In situ forces and length patterns of the fibular collateral ligament under controlled loading: an in vitro biomechanical study using a robotic system.

PubMed

Liu, Ping; Wang, Jianquan; Xu, Yan; Ao, Yingfang

2015-04-01

The aim of this study was to determine the in situ forces and length patterns of the fibular collateral ligament (FCL) and kinematics of the knee under various loading conditions. Six fresh-frozen cadaveric knees were used (mean age 46 ± 14.4 years; range 20-58). In situ forces and length patterns of FCL and kinematics of the knee were determined under the following loading conditions using a robotic/universal force-moment sensor testing system: no rotation, varus (10 Nm), external rotation (5 Nm), and internal rotation (5 Nm) at 0°, 15°, 30°, 60º, 90°, and 120° of flexion, respectively. Under no rotation loading, the distances between the centres of the FCL attachments decreased as the knee flexed. Under varus loading, the force in FCL peaked at 15° of flexion and decreased with further knee flexion, while distances remained nearly constant and the varus rotation increased with knee flexion. Using external rotation, the force in the FCL also peaked at 15° flexion and decreased with further knee flexion, the distances decreased with flexion, and external rotation increased with knee flexion. Using internal rotation load, the force in the FCL was relatively small across all knee flexion angles, and the distances decreased with flexion; the amount of internal rotation was fairly constant. FCL has a primary role in preventing varus and external rotation at 15° of flexion. The FCL does not perform isometrically following knee flexion during neutral rotation, and tibia rotation has significant effects on the kinematics of the FCL. Varus and external rotation laxity increased following knee flexion. By providing more realistic data about the function and length patterns of the FCL and the kinematics of the intact knee, improved reconstruction and rehabilitation protocols can be developed.

Immediate effect of valgus bracing on knee joint moments in meniscectomised patients: An exploratory study.

PubMed

Thorning, Maria; Thorlund, Jonas B; Roos, Ewa M; Wrigley, Tim V; Hall, Michelle

2016-12-01

Patients undergoing medial arthroscopic partial meniscectomy are at increased risk of developing and/or progressing knee osteoarthritis, with increased medial compartment load being a potential contributor. The aim of this study was to evaluate the immediate effect of a valgus unloader knee brace on knee joint moments in patients following medial arthroscopic partial meniscectomy. Within-participant design. Twenty-two patients (age 35-55 years) who had undergone medial arthroscopic partial meniscectomy within the previous 8-15 months completed three-dimensional analysis of gait, forward lunge and one-leg rise during two conditions: with and without a valgus unloader knee brace. Outcome measures included the peak and impulse of the knee adduction moment and the peak knee flexion moment. The peak knee flexion moment increased during brace condition for forward lunge (mean difference [95% CI]) 0.54 [0.27-0.82] (Nm/(BW×HT)%), p<0.001 and one-leg rise (mean difference 0.45 [95% CI 0.08-0.82] (Nm/(BW×HT)%), p=0.022). No other significant differences were found between conditions in any of the included tasks. A significant effect of the knee brace was detected in terms of an increase in peak knee flexion moment during the more demanding tasks such as forward lunge and one-leg rise. This increase implies enhanced stability of the knee provided by the brace, which may induce increased knee function and knee-related confidence during strenuous tasks. Future research is required to explore the structural implications. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Elongation of the collateral ligaments after cruciate retaining total knee arthroplasty and the maximum flexion of the knee.

PubMed

Park, Kwan Kyu; Hosseini, Ali; Tsai, Tsung-Yuan; Kwon, Young-Min; Li, Guoan

2015-02-05

The mechanisms that affect knee flexion after total knee arthroplasty (TKA) are still debatable. This study investigated the elongation of the superficial medial (sMCL) and lateral collateral ligaments (LCL) before and after a posterior cruciate retaining (CR) TKA. We hypothesized that overstretching of the collateral ligaments in high flexion after TKA could reduce maximal flexion of the knee. Three-dimensional models of 11 osteoarthritic knees of 11 patients including the insertions of the collateral ligaments were created using MR images. Each ligament was divided into three equal portions: anterior, middle and posterior portions. The shortest 3D wrapping length of each ligament portion was determined before and after the TKA surgery along a weight-bearing, single leg flexion path. The relationship between the changes of ligament elongation and the changes of the maximal knee flexion after TKAs was quantitatively analyzed. The sMCL showed significant increases in length only at low flexion after TKA; the LCL showed decreases in length at full extension, but increases with further flexion after TKA. The amount of increases of the maximum flexion angle after TKA was negatively correlated with the increases of the elongations of the anterior portion (p=0.010, r=0.733) and middle portion (p=0.049, r=0.604) of the sMCL as well as the anterior portion (p=0.010, r=0.733) of the LCL at maximal flexion of the knee. The results indicated that the increases of the length of the collateral ligaments at maximal flexion after TKA were associated with the decreases of the maximal flexion of the knee. Our data suggest that collateral ligament management should also be evaluated at higher knee flexion angles in order to optimize maximal flexion of the knee after TKAs. Copyright © 2014 Elsevier Ltd. All rights reserved.

In vivo Length Change Patterns of the Medial and Lateral Collateral Ligaments along the Flexion Path of the Knee

PubMed Central

Hosseini, Ali; Qi, Wei; Tsai, Tsung-Yuan; Liu, Yujie; Rubash, Harry; Li, Guoan

2014-01-01

Purpose The knowledge of the function of the collateral ligaments – i.e., superficial medial collateral ligament (sMCL), deep medial collateral ligament (dMCL) and lateral collateral ligament (LCL) – in the entire range of knee flexion is important for soft tissue balance during total knee arthroplasty. The objective of this study was to investigate the length changes of different portions (anterior, middle and posterior) of the sMCL, dMCL and LCL during in vivo weightbearing flexion from full extension to maximal knee flexion. Methods Using a dual fluoroscopic imaging system eight healthy knees were imaged while performing a lunge from full extension to maximal flexion. The length changes of each portion of the collateral ligaments were measured along the flexion path of the knee. Results All anterior portions of the collateral ligaments were shown to have increasing length with flexion except that of the sMCL which showed a reduction in length at high flexion. The middle portions showed minimal change in lengths except that of the sMCL which showed a consistent reduction in length with flexion. All posterior portions showed reduction in lengths with flexion. Conclusions These data indicated that every portion of the ligaments may play important roles in knee stability at different knee flexion range. The soft tissue releasing during TKA may need to consider the function of the ligament portions along the entire flexion path including maximum flexion. PMID:25239504

Bracing of the Reconstructed and Osteoarthritic Knee during High Dynamic Load Tasks.

PubMed

Hart, Harvi F; Crossley, Kay M; Collins, Natalie J; Ackland, David C

2017-06-01

Lateral compartment osteoarthritis accompanied by abnormal knee biomechanics is frequently reported in individuals with knee osteoarthritis after anterior cruciate ligament reconstruction (ACLR). The aim of this study was to evaluate changes in knee biomechanics produced by an adjusted and unadjusted varus knee brace during high dynamic loading activities in individuals with lateral knee osteoarthritis after ACLR and valgus malalignment. Nineteen participants who had undergone ACLR 5 to 20 yr previously and had symptomatic and radiographic lateral knee osteoarthritis with valgus malalignment were assessed. Quantitative motion analysis experiments were conducted during hopping, stair ascent, and descent under three test conditions: (i) no brace, (ii) unadjusted brace with sagittal plane support and neutral frontal plane alignment, and (iii) adjusted brace with sagittal plane support and varus realignment (valgus to neutral). Sagittal, frontal, and transverse plane knee kinematics, external joint moment, and angular impulse data were calculated. Relative to an unbraced knee, braced conditions significantly increased knee flexion and adduction angles during hopping (P = 0.003 and P = 0.005; respectively), stair ascent (P = 0.003 and P < 0.001, respectively), and descent (P = 0.009 and P < 0.001, respectively). In addition, the brace conditions increased knee flexion (P < 0.001) and adduction (P = 0.001) angular impulses and knee stiffness (P < 0.001) during hopping, as well as increased knee adduction moments during stair ascent (P = 0.008) and flexion moments during stair descent (P = 0.006). There were no significant differences between the adjusted and the unadjusted brace conditions (P > 0.05). A knee brace, with or without varus alignment, can modulate knee kinematics and external joint moments during hopping, stairs ascent, and descent in individuals with predominant lateral knee osteoarthritis after ACLR. Longer-term use of a brace may have implications in slowing osteoarthritis progression.

The importance of bony impingement in restricting flexion after total knee arthroplasty: computer simulation model with clinical correlation.

PubMed

Mizu-Uchi, Hideki; Colwell, Clifford W; Fukagawa, Shingo; Matsuda, Shuichi; Iwamoto, Yukihide; D'Lima, Darryl D

2012-10-01

We constructed patient-specific models from computed tomography data after total knee arthroplasty to predict knee flexion based on implant-bone impingement. The maximum flexion before impingement between the femur and the tibial insert was computed using a musculoskeletal modeling program (KneeSIM; LifeModeler, Inc, San Clemente, California) during a weight-bearing deep knee bend. Postoperative flexion was measured in a clinical cohort of 21 knees (low-flex group: 6 knees with <100° of flexion and high-flex group: 15 size-matched knees with >125° of flexion at 2 years). Average predicted flexion angles were within 2° of clinical measurements for the high-flex group. In the low-flex group, 4 cases had impingement involving the bone cut at the posterior condyle, and the average predicted knee flexion was 102° compared with 93° measured clinically. These results indicate that the level of the distal femoral resection should be carefully planned and that exposed bone proximal to the tips of the posterior condyles of the femoral component should be removed if there is risk of impingement. Copyright © 2012 Elsevier Inc. All rights reserved.

Impact of Soft Tissue Imbalance on Knee Flexion Angle After Posterior Stabilized Total Knee Arthroplasty.

PubMed

Tsukada, Sachiyuki; Fujii, Tomoko; Wakui, Motohiro

2017-08-01

This study was performed to assess the impact of soft tissue imbalance on the knee flexion angle 2 years after posterior stabilized total knee arthroplasty (TKA). A total of 329 consecutive varus knees were included to assess the association of knee flexion angle 2 years after TKA with preoperative, intraoperative, and postoperative variables. All intraoperative soft tissue measurements were performed by a single surgeon under spinal anesthesia in a standardized manner including the subvastus approach, reduced patella, and without use of a pneumonic tourniquet. Multiple linear regression analysis showed no significant correlations in terms of intraoperative valgus imbalance at 90-degree flexion or the difference in soft tissue tension between 90-degree flexion and 0-degree extension (β = -0.039; 95% confidence interval [CI], -0.88 to 0.80; P = .93 and β = 0.015; 95% CI, -0.29 to 0.32; P = .92, respectively). Preoperative flexion angle was significantly correlated with knee flexion angle 2 years after TKA (β = 0.42; 95% CI, 0.33 to 0.51; P < .0001). Avoiding valgus imbalance at 90-degree flexion and aiming for strictly equal soft tissue tension between 90-degree flexion and 0-degree extension had little practical value with regard to knee flexion angle 2 years after posterior stabilized TKA. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Long-term results after distal rectus femoris transfer as a part of multilevel surgery for the correction of stiff-knee gait in spastic diplegic cerebral palsy.

PubMed

Dreher, Thomas; Wolf, Sebastian I; Maier, Michael; Hagmann, Sébastien; Vegvari, Dóra; Gantz, Simone; Heitzmann, Daniel; Wenz, Wolfram; Braatz, Frank

2012-10-03

The evidence for distal rectus femoris transfer as a part of multilevel surgery for the correction of stiff-knee gait in children with spastic diplegic cerebral palsy is limited because of inconsistent outcomes reported in various studies and the lack of long-term evaluations. This study investigated the long-term results (mean, nine years) for fifty-three ambulatory patients with spastic diplegic cerebral palsy and stiff-knee gait treated with standardized distal rectus femoris transfer as a part of multilevel surgery. Standardized three-dimensional gait analysis and clinical examination were carried out before surgery and at one year and nine years after surgery. Patients with decreased peak knee flexion in swing phase who had distal rectus femoris transfer to correct the decreased peak knee flexion in swing phase (C-DRFT) were evaluated separately from those with normal or increased peak knee flexion in swing phase who had distal rectus femoris transfer done as a prophylactic procedure (P-DRFT). A significantly increased peak knee flexion in swing phase was found in the C-DRFT group one year after surgery, while a significant loss (15°) in peak knee flexion in swing phase was noted in the P-DRFT group. A slight but not significant increase in peak knee flexion in swing phase in both groups was noted at the time of the long-term follow-up. A significant improvement in timing of peak knee flexion in swing phase was only found for the C-DRFT group, and was maintained after nine years. Knee motion and knee flexion velocity were significantly increased in both groups and were maintained at long-term follow-up in the C-DRFT group, while the P-DRFT showed a deterioration of knee motion. Distal rectus femoris transfer is an effective procedure to treat stiff-knee gait featuring decreased peak knee flexion in swing phase and leads to a long-lasting increase of peak knee flexion in swing phase nine years after surgery. Patients with more involvement showed a greater potential to benefit from distal rectus femoris transfer. However, 18% of the patients showed a permanently poor response and 15% developed recurrence. In patients with severe knee flexion who underwent a prophylactic distal rectus femoris transfer, a significant loss in peak knee flexion in swing phase was noted and thus a prophylactic distal rectus femoris transfer may not be indicated in these patients. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Sharper angle, higher risk? The effect of cutting angle on knee mechanics in invasion sport athletes.

PubMed

Schreurs, Mervin J; Benjaminse, Anne; Lemmink, Koen A P M

2017-10-03

Cutting is an important skill in team-sports, but unfortunately is also related to non-contact ACL injuries. The purpose was to examine knee kinetics and kinematics at different cutting angles. 13 males and 16 females performed cuts at different angles (45°, 90°, 135° and 180°) at maximum speed. 3D kinematics and kinetics were collected. To determine differences across cutting angles (45°, 90°, 135° and 180°) and sex (female, male), a 4×2 repeated measures ANOVA was conducted followed by post hoc comparisons (Bonferroni) with alpha level set at α≤0.05a priori. At all cutting angles, males showed greater knee flexion angles than females (p<0.01). Also, where males performed all cutting angles with no differences in the amount of knee flexion -42.53°±8.95°, females decreased their knee flexion angle from -40.6°±7.2° when cutting at 45° to -36.81°±9.10° when cutting at 90°, 135° and 180° (p<0.01). Knee flexion moment decreased for both sexes when cutting towards sharper angles (p<0.05). At 90°, 135° and 180°, males showed greater knee valgus moments than females. For both sexes, knee valgus moment increased towards the sharper cutting angles and then stabilized compared to the 45° cutting angle (p<0.01). Both females and males showed smaller vGRF when cutting to sharper angles (p<0.01). It can be concluded that different cutting angles demand different knee kinematics and kinetics. Sharper cutting angles place the knee more at risk. However, females and males handle this differently, which has implications for injury prevention. Copyright © 2017 Elsevier Ltd. All rights reserved.

Contributions of muscles and passive dynamics to swing initiation over a range of walking speeds.

PubMed

Fox, Melanie D; Delp, Scott L

2010-05-28

Stiff-knee gait is a common walking problem in cerebral palsy characterized by insufficient knee flexion during swing. To identify factors that may limit knee flexion in swing, it is necessary to understand how unimpaired subjects successfully coordinate muscles and passive dynamics (gravity and velocity-related forces) to accelerate the knee into flexion during double support, a critical phase just prior to swing that establishes the conditions for achieving sufficient knee flexion during swing. It is also necessary to understand how contributions to swing initiation change with walking speed, since patients with stiff-knee gait often walk slowly. We analyzed muscle-driven dynamic simulations of eight unimpaired subjects walking at four speeds to quantify the contributions of muscles, gravity, and velocity-related forces (i.e. Coriolis and centrifugal forces) to preswing knee flexion acceleration during double support at each speed. Analysis of the simulations revealed contributions from muscles and passive dynamics varied systematically with walking speed. Preswing knee flexion acceleration was achieved primarily by hip flexor muscles on the preswing leg with assistance from biceps femoris short head. Hip flexors on the preswing leg were primarily responsible for the increase in preswing knee flexion acceleration during double support with faster walking speed. The hip extensors and abductors on the contralateral leg and velocity-related forces opposed preswing knee flexion acceleration during double support. Copyright 2010 Elsevier Ltd. All rights reserved.

Contributions of muscles and passive dynamics to swing initiation over a range of walking speeds

PubMed Central

Fox, Melanie D.; Delp, Scott L.

2010-01-01

Stiff-knee gait is a common walking problem in cerebral palsy characterized by insufficient knee flexion during swing. To identify factors that may limit knee flexion in swing, it is necessary to understand how unimpaired subjects successfully coordinate muscles and passive dynamics (gravity and velocity-related forces) to accelerate the knee into flexion during double support, a critical phase just prior to swing that establishes the conditions for achieving sufficient knee flexion during swing. It is also necessary to understand how contributions to swing initiation change with walking speed, since patients with stiff-knee gait often walk slowly. We analyzed muscle-driven dynamic simulations of eight unimpaired subjects walking at four speeds to quantify the contributions of muscles, gravity, and velocity-related forces (i.e. Coriolis and centrifugal forces) to preswing knee flexion acceleration during double support at each speed. Analysis of the simulations revealed contributions from muscles and passive dynamics varied systematically with walking speed. Preswing knee flexion acceleration was achieved primarily by hip flexor muscles on the preswing leg with assistance from biceps femoris short head. Hip flexors on the preswing leg were primarily responsible for the increase in preswing knee flexion acceleration during double support with faster walking speed. The hip extensors and abductors on the contralateral leg and velocity-related forces opposed preswing knee flexion acceleration during double support. PMID:20236644

Contact forces in the tibiofemoral joint from soft tissue tensions: Implications to soft tissue balancing in total knee arthroplasty.

PubMed

Verstraete, Matthias A; Meere, Patrick A; Salvadore, Gaia; Victor, Jan; Walker, Peter S

2017-06-14

Proper tension of the knee's soft tissue envelope is important during total knee arthroplasty; incorrect tensioning potentially leads to joint stiffness or instability. The latter remains an important trigger for revision surgery. The use of sensors quantifying the intra-articular loads, allows surgeons to assess the ligament tension at the time of surgery. However, realistic target values are missing. In the framework of this paper, eight non-arthritic cadaveric specimens were tested and the intra-articular loads transferred by the medial and lateral compartment were measured using custom sensor modules. These modules were inserted below the articulating surfaces of the proximal tibia, with the specimens mounted on a test setup that mimics surgical conditions. For both compartments, the highest loads are observed in full extension. While creating knee flexion by lifting the femur and flexing the hip, mean values (standard deviation) of 114N (71N) and 63N (28N) are observed at 0° flexion for the medial and lateral compartment respectively. Upon flexion, both medial and lateral loads decrease with mean values at 90° flexion of 30N (22N) and 6N (5N) respectively. The majority of the load is transmitted through the medial compartment. These observations are linked to the deformation of the medial and lateral collaterals, in addition to the anatomy of the passive soft tissues surrounding the knee. In conclusion, these findings provide tangible clinical guidance in assessing the soft tissue loads when dealing with anatomically designed total knee implants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modelling and Analysis on Biomechanical Dynamic Characteristics of Knee Flexion Movement under Squatting

PubMed Central

Wang, Jianping; Tao, Kun; Li, Huanyi; Wang, Chengtao

2014-01-01

The model of three-dimensional (3D) geometric knee was built, which included femoral-tibial, patellofemoral articulations and the bone and soft tissues. Dynamic finite element (FE) model of knee was developed to simulate both the kinematics and the internal stresses during knee flexion. The biomechanical experimental system of knee was built to simulate knee squatting using cadaver knees. The flexion motion and dynamic contact characteristics of knee were analyzed, and verified by comparing with the data from in vitro experiment. The results showed that the established dynamic FE models of knee are capable of predicting kinematics and the contact stresses during flexion, and could be an efficient tool for the analysis of total knee replacement (TKR) and knee prosthesis design. PMID:25013852

Target of physiological gait: Realization of speed adaptive control for a prosthetic knee during swing flexion.

PubMed

Cao, Wujing; Yu, Hongliu; Zhao, Weiliang; Li, Jin; Wei, Xiaodong

2018-01-01

Prosthetic knee is the most important component of lower limb prosthesis. Speed adaptive for prosthetic knee during swing flexion is the key method to realize physiological gait. This study aims to discuss the target of physiological gait, propose a speed adaptive control method during swing flexion and research the damping adjustment law of intelligent hydraulic prosthetic knee. According to the physiological gait trials of healthy people, the control target during swing flexion is defined. A new prosthetic knee with fuzzy logical control during swing flexion is designed to realize the damping adjustment automatically. The function simulation and evaluation system of intelligent knee prosthesis is provided. Speed adaptive control test of the intelligent prosthetic knee in different velocities are researched. The maximum swing flexion of the knee angle is set between sixty degree and seventy degree as the target of physiological gait. Preliminary experimental results demonstrate that the prosthetic knee with fuzzy logical control is able to realize physiological gait under different speeds. The faster the walking, the bigger the valve closure percentage of the hydraulic prosthetic knee. The proposed fuzzy logical control strategy and intelligent hydraulic prosthetic knee are effective for the amputee to achieve physiological gait.

Examining Ankle-Joint Laxity Using 2 Knee Positions and With Simulated Muscle Guarding

PubMed Central

Hanlon, Shawn; Caccese, Jaclyn; Knight, Christopher A.; Swanik, Charles “Buz”; Kaminski, Thomas W.

2016-01-01

Context:  Several factors affect the reliability of the anterior drawer and talar tilt tests, including the individual clinician's experience and skill, ankle and knee positioning, and muscle guarding. Objectives:  To compare gastrocnemius activity during the measurement of ankle-complex motion at different knee positions, and secondarily, to compare ankle-complex motion during a simulated trial of muscle guarding. Design:  Cross-sectional study. Setting:  Research laboratory. Patients or Other Participants:  Thirty-three participants aged 20.2 ± 1.7 years were tested. Intervention(s):  The ankle was loaded under 2 test conditions (relaxed, simulated muscle guarding) at 2 knee positions (0°, 90° of flexion) while gastrocnemius electromyography (EMG) activity was recorded. Main Outcome Measure(s):  Anterior displacement (mm), inversion-eversion motion (°), and peak EMG amplitude values of the gastrocnemius (μV). Results:  Anterior displacement did not differ between the positions of 0° and 90° of knee flexion (P = .193). Inversion-eversion motion was greater at 0° of knee flexion compared with 90° (P < .001). Additionally, peak EMG amplitude of the gastrocnemius was not different between 0° and 90° of knee flexion during anterior displacement (P = .101). As expected, the simulated muscle-guarding trial reduced anterior displacement compared with the relaxed condition (0° of knee flexion, P = .008; 90° of knee flexion, P = .016) and reduced inversion-eversion motion (0° of knee flexion, P = .03; 90° of knee flexion, P < .001). Conclusions:  In a relaxed state, the gastrocnemius muscle did not appear to affect anterior ankle laxity at the 2 most common knee positions for anterior drawer testing; however, talar tilt testing may be best performed with the knee in 0° of knee flexion. Finally, our outcomes from the simulated muscle-guarding condition suggest that clinicians should use caution and be aware of reduced perceived laxity when performing these clinical examination techniques immediately postinjury. PMID:26881870

Examining Ankle-Joint Laxity Using 2 Knee Positions and With Simulated Muscle Guarding.

PubMed

Hanlon, Shawn; Caccese, Jaclyn; Knight, Christopher A; Swanik, Charles Buz; Kaminski, Thomas W

2016-02-01

Several factors affect the reliability of the anterior drawer and talar tilt tests, including the individual clinician's experience and skill, ankle and knee positioning, and muscle guarding. To compare gastrocnemius activity during the measurement of ankle-complex motion at different knee positions, and secondarily, to compare ankle-complex motion during a simulated trial of muscle guarding. Cross-sectional study. Research laboratory. Thirty-three participants aged 20.2 ± 1.7 years were tested. The ankle was loaded under 2 test conditions (relaxed, simulated muscle guarding) at 2 knee positions (0°, 90° of flexion) while gastrocnemius electromyography (EMG) activity was recorded. Anterior displacement (mm), inversion-eversion motion (°), and peak EMG amplitude values of the gastrocnemius (μV). Anterior displacement did not differ between the positions of 0° and 90° of knee flexion (P = .193). Inversion-eversion motion was greater at 0° of knee flexion compared with 90° (P < .001). Additionally, peak EMG amplitude of the gastrocnemius was not different between 0° and 90° of knee flexion during anterior displacement (P = .101). As expected, the simulated muscle-guarding trial reduced anterior displacement compared with the relaxed condition (0° of knee flexion, P = .008; 90° of knee flexion, P = .016) and reduced inversion-eversion motion (0° of knee flexion, P = .03; 90° of knee flexion, P < .001). In a relaxed state, the gastrocnemius muscle did not appear to affect anterior ankle laxity at the 2 most common knee positions for anterior drawer testing; however, talar tilt testing may be best performed with the knee in 0° of knee flexion. Finally, our outcomes from the simulated muscle-guarding condition suggest that clinicians should use caution and be aware of reduced perceived laxity when performing these clinical examination techniques immediately postinjury.

Active Flexion in Weight Bearing Better Correlates with Functional Outcomes of Total Knee Arthroplasty than Passive Flexion.

PubMed

Song, Young Dong; Jain, Nimash; Kang, Yeon Gwi; Kim, Tae Yune; Kim, Tae Kyun

2016-06-01

Correlations between maximum flexion and functional outcomes in total knee arthroplasty (TKA) patients are reportedly weak. We investigated whether there are differences between passive maximum flexion in nonweight bearing and other types of maximum flexion and whether the type of maximum flexion correlates with functional outcomes. A total of 210 patients (359 knees) underwent preoperative evaluation and postoperative follow-up evaluations (6, 12, and 24 months) for the assessment of clinical outcomes including maximum knee flexion. Maximum flexion was measured under five conditions: passive nonweight bearing, passive weight bearing, active nonweight bearing, and active weight bearing with or without arm support. Data were analyzed for relationships between passive maximum flexion in nonweight bearing by Pearson correlation analyses, and a variance comparison between measurement techniques via paired t test. We observed substantial differences between passive maximum flexion in nonweight bearing and the other four maximum flexion types. At all time points, passive maximum flexion in nonweight bearing correlated poorly with active maximum flexion in weight bearing with or without arm support. Active maximum flexion in weight bearing better correlated with functional outcomes than the other maximum flexion types. Our study suggests active maximum flexion in weight bearing should be reported together with passive maximum flexion in nonweight bearing in research on the knee motion arc after TKA.

Active Flexion in Weight Bearing Better Correlates with Functional Outcomes of Total Knee Arthroplasty than Passive Flexion

PubMed Central

Song, Young Dong; Jain, Nimash; Kang, Yeon Gwi; Kim, Tae Yune

2016-01-01

Purpose Correlations between maximum flexion and functional outcomes in total knee arthroplasty (TKA) patients are reportedly weak. We investigated whether there are differences between passive maximum flexion in nonweight bearing and other types of maximum flexion and whether the type of maximum flexion correlates with functional outcomes. Materials and Methods A total of 210 patients (359 knees) underwent preoperative evaluation and postoperative follow-up evaluations (6, 12, and 24 months) for the assessment of clinical outcomes including maximum knee flexion. Maximum flexion was measured under five conditions: passive nonweight bearing, passive weight bearing, active nonweight bearing, and active weight bearing with or without arm support. Data were analyzed for relationships between passive maximum flexion in nonweight bearing by Pearson correlation analyses, and a variance comparison between measurement techniques via paired t test. Results We observed substantial differences between passive maximum flexion in nonweight bearing and the other four maximum flexion types. At all time points, passive maximum flexion in nonweight bearing correlated poorly with active maximum flexion in weight bearing with or without arm support. Active maximum flexion in weight bearing better correlated with functional outcomes than the other maximum flexion types. Conclusions Our study suggests active maximum flexion in weight bearing should be reported together with passive maximum flexion in nonweight bearing in research on the knee motion arc after TKA. PMID:27274468

Global analysis of sagittal spinal alignment in major deformities: correlation between lack of lumbar lordosis and flexion of the knee.

PubMed

Obeid, Ibrahim; Hauger, Olivier; Aunoble, Stéphane; Bourghli, Anouar; Pellet, Nicolas; Vital, Jean-Marc

2011-09-01

It has become well recognised that sagittal balance of the spine is the result of an interaction between the spine and the pelvis. Knee flexion is considered to be the last compensatory mechanism in case of sagittal imbalance, but only few studies have insisted on the relationship between spino-pelvic parameters and lower extremity parameters. Correlation between the lack of lumbar lordosis and knee flexion has not yet been established. A retrospective study was carried out on 28 patients with major spinal deformities. The EOS system was used to measure spinal and pelvic parameters and the knee flexion angle; the lack of lumbar lordosis was calculated after prediction of lumbar lordosis with two different formulas. Correlation analysis between the different measured parameters was performed. Lumbar lordosis correlated with sacral slope (r = -0.71) and moderately with knee flexion angle (r = 0.42). Pelvic tilt correlated moderately with knee flexion angle (r = 0.55). Lack of lumbar lordosis correlated best with knee flexion angle (r = 0.72 and r = 0.63 using the two formulas, respectively). Knee flexion as a compensatory mechanism to sagittal imbalance was well correlated to the lack of lordosis and, depending on the importance of the former parameter, the best procedure to correct sagittal imbalance could be chosen.

Does patella position influence ligament balancing in total knee arthroplasty?

PubMed

Yoon, Jung-Ro; Oh, Kwang-Jun; Wang, Joon Ho; Yang, Jae-Hyuk

2015-07-01

In vivo comparative gap measurements were performed in three different patella positions (reduced, subluxated and everted) using offset-type-force-controlled-spreader-system. Prospectively, 50 knees were operated by total knee arthroplasty using a navigation-assisted gap-balancing technique. The offset-type-force-controlled-spreader-system was used for gap measurements. This commercially available instrument allows controllable tension in patella-reduced position. The mediolateral gaps of knee extension (0°) and flexion (90°) angle were recorded in three different patella positions; reduced, subluxated and everted. Any gap differences of more than 3 mm were considered as a meaningful difference. Correlation between the difference with the demographic data, preoperative radiologic alignment and intraoperative data was analysed. For statistical analysis, ANOVA and Pearson's correlation test were used. The gaps in patella eversion demonstrated smaller gaps both in knee extension and flexion position compared to the gaps of patella reduction position. The amount of decreased gaps was more definite in knee flexion position. Statistically significant difference was observed for the lateral gap of patella eversion compared to gap of patella reduction in knee flexion position (p < 0.05). There were notable cases of variability in knee flexion position. Significant portion of 12 (24 %) knees of patella subluxation and 33 (66 %) knees of patella evertion demonstrated either increased or decreased gaps in knee flexion position compared to the gaps of patella reduction position. The gaps in patella eversion demonstrated smaller gaps both in knee extension and flexion position compared to the gaps of patella reduction position. The amount of decreased gaps was more definite in knee flexion position. Therefore, the intraoperative patellar positioning has influence on the measurement of the joint gap. Keeping the patella in reduced position is important during gap balancing. I.

Immersive virtual reality improves movement patterns in patients after ACL reconstruction: implications for enhanced criteria-based return-to-sport rehabilitation.

PubMed

Gokeler, Alli; Bisschop, Marsha; Myer, Gregory D; Benjaminse, Anne; Dijkstra, Pieter U; van Keeken, Helco G; van Raay, Jos J A M; Burgerhof, Johannes G M; Otten, Egbert

2016-07-01

The purpose of this study was to evaluate the influence of immersion in a virtual reality environment on knee biomechanics in patients after ACL reconstruction (ACLR). It was hypothesized that virtual reality techniques aimed to change attentional focus would influence altered knee flexion angle, knee extension moment and peak vertical ground reaction force (vGRF) in patients following ACLR. Twenty athletes following ACLR and 20 healthy controls (CTRL) performed a step-down task in both a non-virtual reality environment and a virtual reality environment displaying a pedestrian traffic scene. A motion analysis system and force plates were used to measure kinematics and kinetics during a step-down task to analyse each single-leg landing. A significant main effect was found for environment for knee flexion excursion (P = n.s.). Significant interaction differences were found between environment and groups for vGRF (P = 0.004), knee moment (P < 0.001), knee angle at peak vGRF (P = 0.01) and knee flexion excursion (P = 0.03). There was larger effect of virtual reality environment on knee biomechanics in patients after ACLR compared with controls. Patients after ACLR immersed in virtual reality environment demonstrated knee joint biomechanics that approximate those of CTRL. The results of this study indicate that a realistic virtual reality scenario may distract patients after ACLR from conscious motor control. Application of clinically available technology may aid in current rehabilitation programmes to target altered movement patterns after ACLR. Diagnostic study, Level III.

Continuous femoral versus epidural block for attainment of 120° knee flexion after total knee arthroplasty: a randomized controlled trial.

PubMed

Sakai, Norihiro; Inoue, Takaya; Kunugiza, Yasuo; Tomita, Tetsuya; Mashimo, Takashi

2013-05-01

We conducted the prospective randomized controlled trial to test that continuous femoral nerve block (CFNB) improves attainment of 120° knee flexion compared to continuous epidural analgesia (CEA). Sixty-six patients scheduled for unilateral total knee arthroplasty were randomized into two groups; infusion of ropivacaine 0.15% into CEA or CFNB to third postoperative days. We studied the time required to attain 120° knee flexion, variations in thigh and calf circumferences around the treated knee, pain scores, rehabilitation milestones, the need for adjuvant analgesics, and side effects. CFNB patients attained earlier knee flexion to 120°, lower variations in thigh and calf circumferences, less pain during rehabilitation, and less need for adjuvant analgesics. CFNB is a better pain management strategy that accelerates knee flexion rehabilitation. Copyright © 2013 Elsevier Inc. All rights reserved.

Influence of bi- and tri-compartmental knee arthroplasty on the kinematics of the knee joint.

PubMed

Wünschel, Markus; Lo, Jiahsuan; Dilger, Torsten; Wülker, Nikolaus; Müller, Otto

2011-01-27

The cruciate ligaments are important stabilizers of the knee joint and determine joint kinematics in the natural knee and after cruciate retaining arthroplasty.No in vitro data is available to biomechanically evaluate the ability of the anterior cruciate ligament (ACL) to maintain knee joint kinematics after bicruciate-retaining bi-compartmental knee arthroplasty (BKA).Therefore, the objective of the current study was to investigate the kinematics of the natural knee joint, before and after installing bicruciate-retaining BKA and posterior cruciate retaining total knee arthroplasty. Specifically, we incorporated a dynamic knee simulator to simulate weight-bearing flexions on cadaveric knee specimen before and after surgical manipulations. In this cadaveric study we investigated rotational and translational tibiofemoral kinematics during simulated weight-bearing flexions of the intact knee, after bi-compartmental knee arthroplasty (BKA+), after resecting the ACL in BKA (BKA-), and after posterior cruciate retaining total knee arthroplasty (TKA). Rotation of BKA+ is closest to the intact knee joint, whereas TKA shows significant differences from 30 to 90 degree of flexion. Within the tested flexion range (15 to 90 degree of flexion), there was no significant difference in the anterior-posterior translation among intact, BKA+, and TKA knees. Resecting the ACL in BKA leads to a significant anterior tibial translation. BKA with intact cruciate ligaments resembles rotation and translation of the natural knee during a simulated weight-bearing flexion. It is a suitable treatment option for medial and patellofemoral osteoarthritis with advantages in rotational characteristics compared to TKA.

Does the Q - H index show a stronger relationship than the H:Q ratio in regard to knee pain during daily activities in patients with knee osteoarthritis?

PubMed

Fujita, Remi; Matsui, Yasumoto; Harada, Atsushi; Takemura, Marie; Kondo, Izumi; Nemoto, Tetsuya; Sakai, Tadahiro; Hiraiwa, Hideki; Ota, Susumu

2016-12-01

[Purpose] The purpose of this study was to elucidate the relationship between knee muscle strength and knee pain in activities of daily living, based on consideration of the difference between extension and flexion strength (Q - H) and the hamstring:quadriceps (H:Q) ratio in patients with knee osteoarthritis. [Subjects and Methods] The participants were 78 females with knee osteoarthritis, and a total of 133 knees that had not been treated surgically were the targets of this research. The legs were divided according to dominance. Isometric knee extension and flexion muscle strength and knee pain during activities of daily living were measured. The H:Q ratio (flexion/extension muscle strength) and the difference between extension and flexion strength, (extension muscle strength/weight) minus (flexion muscle strength/weight), that is, Q - H, were calculated. The correlation between these indices and the knee pain score during activities of daily living was investigated. [Results] Greater knee pain during activities of daily living was related to lower knee extension muscle strength and Q - H in both the dominant and nondominant legs. Knee flexion muscle strength and the H:Q ratio were not significantly correlated with knee pain during any activities of daily living. [Conclusion] Knee extension muscle strength and Q - H were found to be significantly correlated with knee pain during activities of daily living, whereas the H:Q ratio was not.

Analysis of the Flexion Gap on In Vivo Knee Kinematics Using Fluoroscopy.

PubMed

Nakamura, Shinichiro; Ito, Hiromu; Yoshitomi, Hiroyuki; Kuriyama, Shinichi; Komistek, Richard D; Matsuda, Shuichi

2015-07-01

There is a paucity of information on the relationships between postoperative knee laxity and in vivo knee kinematics. The correlations were analyzed in 22 knees with axial radiographs and fluoroscopy based 3D model fitting approach after a tri-condylar total knee arthroplasty. During deep knee bend activities, the medial flexion gap had significant correlations with the medial contact point (r=0.529, P=0.011) and axial rotation at full extension. During kneeling activities, a greater medial flexion gap caused larger anterior translation at complete contact (r=0.568, P=0.011). Meanwhile, the lateral flexion gap had less effect. In conclusion, laxity of the medial collateral ligament should be avoided because the magnitude of medial flexion stability was crucial for postoperative knee kinematics. Copyright © 2015 Elsevier Inc. All rights reserved.

Measurement of knee stiffness and laxity in patients with documented absence of the anterior cruciate ligament.

PubMed

Markolf, K L; Kochan, A; Amstutz, H C

1984-02-01

Thirty-five patients with documented absence of the anterior cruciate ligament were tested on the University of California, Los Angeles, instrumented clinical knee-testing apparatus and we measured the response curves for the following testing modes: anterior-posterior force versus displacement at full extension and at 20 and 90 degrees of flexion; varus-valgus moment versus angulation at full extension and 20 degrees of flexion; and tibial torque versus rotation at 20 degrees of flexion. Absolute values of stiffness and laxity and right-left differences for these injured knees were compared with identical quantities measured previously for a control population of forty-nine normal subjects with no history of treatment for injury to the knee. For both the uninjured knees and the knees without an anterior cruciate ligament, at 20 and 90 degrees of flexion the anterior-posterior laxity was greatest at approximately 15 degrees of external rotation of the foot. The injured knees demonstrated significantly increased total anterior-posterior laxity and decreased anterior stiffness when compared with the uninjured knees in all tested positions of the foot and knee. The mean increase in paired anterior-posterior laxity for the injured knees in this group of patients at +/- 200 newtons of applied anterior-posterior force was 3.1 millimeters (+39 per cent) at full extension, 5.5 millimeters (+57 per cent) at 20 degrees of flexion, and 2.5 millimeters (+34 per cent) at 90 degrees of flexion. The mean reduction in anterior stiffness for injured knees was also greatest (-54 per cent) at 20 degrees of knee flexion. Only slight reduction in posterior stiffness (-16 per cent) was measured at 20 degrees of flexion, and this probably reflected the presence of associated capsular and meniscal injuries. In the group of anterior cruciate-deficient knees, the patients with an absent medial meniscus showed greater total anterior-posterior laxity in all three positions of knee flexion than did the patients with an intact or torn meniscus. Varus-valgus laxity at full extension increased an average of 1.7 degrees (+36 per cent) for the injured knees, while varus and valgus stiffness decreased 21 per cent and 24 per cent. Absence of the medial meniscus (in a knee with absence of the anterior cruciate ligament) increased varus-valgus laxity at zero and 20 degrees of flexion.(ABSTRACT TRUNCATED AT 400 WORDS)

Changes in the activity of trunk and hip extensor muscles during bridge exercises with variations in unilateral knee joint angle.

PubMed

Kim, Juseung; Park, Minchul

2016-09-01

[Purpose] This study compared abdominal and hip extensor muscle activity during a bridge exercise with various knee joint angles. [Subjects and Methods] Twenty-two healthy male subjects performed a bridge exercise in which the knee joint angle was altered. While subjects performed the bridge exercise, external oblique, internal oblique, gluteus maximus, and semitendinosus muscle activity was measured using electromyography. [Results] The bilateral external and internal oblique muscle activity was significantly higher at 0° knee flexion compared to 120°, 90°, and 60°. The bilateral gluteus maximus muscle activity was significantly different at 0° of knee flexion compared to 120°, 90°, and 60°. The ipsilateral semitendinosus muscle activity was significantly increased at 90° and 60° of knee flexion compared to 120°, and significantly decreased at 0° knee flexion compared with 120°, 90°, and 60°. The contralateral semitendinosus muscle activity was significantly higher at 60° of knee flexion than at 120°, and significantly higher at 0° of knee flexion than at 120°, 90°, and 60°. [Conclusion] Bridge exercises performed with knee flexion less than 90° may be used to train the ipsilateral semitendinosus. Furthermore, bridge exercise performed with one leg may be used to train abdominal and hip extensor muscles.

Anteroposterior translation does not correlate with knee flexion after total knee arthroplasty.

PubMed

Ishii, Yoshinori; Noguchi, Hideo; Takeda, Mitsuhiro; Sato, Junko; Toyabe, Shin-ichi

2014-02-01

Stiffness after a TKA can cause patient dissatisfaction and diminished function, therefore it is important to characterize predictors of ROM after TKA. Studies of AP translation in conscious individuals disagree whether AP translation affects maximum knee flexion angle after implantation of a highly congruent sphere and trough geometry PCL-substituting prosthesis in a TKA. We investigated whether AP translation correlated with maximum knee flexion angle (1) in patients who were awake, and (2) who were under anesthesia (to minimize the effects of voluntary muscle contraction) in a TKA with implantation of a PCL-substituting mobile-bearing prosthesis. AP translation was examined under both conditions in 34 primary TKAs. Measurements under anesthesia were performed when the patients were having anesthesia for a contralateral TKA. Awake measurements were made within 4 days of that anesthetic session in patients who had no residual sedative effects. The average postoperative interval for the index TKA flexion measurements was 23 months (range, 6-114 months). AP translation was evaluated at 75° flexion using an arthrometer. There was no correlation between postoperative maximum knee flexion and AP translation at 75° during consciousness. There was no correlation between postoperative maximum knee flexion and AP translation under anesthesia. AP translation at 75° flexion did not correlate with postoperative maximum knee flexion in either awake or anesthetized patients during a TKA with implantation of a posterior cruciate-substituting prosthesis.

Primary and coupled motions of the native knee in response to applied varus and valgus load.

PubMed

Gladnick, Brian P; Boorman-Padgett, James; Stone, Kyle; Kent, Robert N; Cross, Michael B; Mayman, David J; Pearle, Andrew D; Imhauser, Carl W

2016-06-01

Knowledge of the complex kinematics of the native knee is a prerequisite for a successful reconstructive procedure. The aim of this study is to describe the primary and coupled motions of the native knee throughout the range of knee flexion, in response to applied varus and valgus loads. Twenty fresh-frozen cadaver knees were affixed to a six degree of freedom robotic arm with a universal force-moment sensor, and loaded with a 4Nm moment in varus and valgus at 0, 15, 30, 45, and 90° of knee flexion. The resulting tibiofemoral angulation, displacement, and rotation were recorded. For each parameter investigated, the knee joint demonstrated more laxity at higher flexion angles. Varus angulation increased progressively from zero (2.0° varus) to 90 (5.2° varus) degrees of knee flexion (p<0.001). Valgus angulation also increased progressively, from zero (1.5° valgus) to 90 (3.9° valgus) degrees of knee flexion (p<0.001). At all flexion angles, the magnitude of tibiofemoral angle deviation was larger with varus than with valgus loading (p<0.05). We conclude that the native knee exhibits small increases in coronal plane laxity as the flexion angle increases, and that the knee has generally more laxity under varus load than with valgus load throughout the Range of Motion (ROM). Larger differences in laxity of more than 2 to 3°, or peak laxity specifically during the range of mid-flexion, were not found in our cadaver model and are not likely to represent normal coronal plane kinematics. Level V, biomechanical cadaveric study. Copyright © 2016 Elsevier B.V. All rights reserved.

Influence of bi- and tri-compartmental knee arthroplasty on the kinematics of the knee joint

PubMed Central

2011-01-01

Background The cruciate ligaments are important stabilizers of the knee joint and determine joint kinematics in the natural knee and after cruciate retaining arthroplasty. No in vitro data is available to biomechanically evaluate the ability of the anterior cruciate ligament (ACL) to maintain knee joint kinematics after bicruciate-retaining bi-compartmental knee arthroplasty (BKA). Therefore, the objective of the current study was to investigate the kinematics of the natural knee joint, before and after installing bicruciate-retaining BKA and posterior cruciate retaining total knee arthroplasty. Specifically, we incorporated a dynamic knee simulator to simulate weight-bearing flexions on cadaveric knee specimen before and after surgical manipulations. Methods In this cadaveric study we investigated rotational and translational tibiofemoral kinematics during simulated weight-bearing flexions of the intact knee, after bi-compartmental knee arthroplasty (BKA+), after resecting the ACL in BKA (BKA-), and after posterior cruciate retaining total knee arthroplasty (TKA). Results Rotation of BKA+ is closest to the intact knee joint, whereas TKA shows significant differences from 30 to 90 degree of flexion. Within the tested flexion range (15 to 90 degree of flexion), there was no significant difference in the anterior-posterior translation among intact, BKA+, and TKA knees. Resecting the ACL in BKA leads to a significant anterior tibial translation. Conclusions BKA with intact cruciate ligaments resembles rotation and translation of the natural knee during a simulated weight-bearing flexion. It is a suitable treatment option for medial and patellofemoral osteoarthritis with advantages in rotational characteristics compared to TKA. PMID:21272328

Arthrometric Evaluation of Stabilizing Effect of Knee Functional Bracing at Different Flexion Angles

PubMed Central

Seyed Mohseni, Saeedeh; Moss, Farzam; Karimi, Hossein; Kamali, Mohammad

2009-01-01

Previous in-vivo investigations on the stabilizing efficacy of knee bracing for ACL reconstructed patients have been often limited to 20-30 degrees of knee flexion. In this study, the effectiveness of a uniaxial hinged functional brace to improve the knee stability was assessed at 30, 60 and 90 degrees of knee flexion. Arthrometry tests were conducted on 15 healthy subjects before and following wearing the brace and the tibial displacements were measured at up to 150 N anterior forces. Results indicated that functional bracing has a significant stabilizing effect throughout the range of knee flexion examined (p < 0.05). The rate of effectiveness, however, was not consistent across the flexion range, e.g., 50% at 30 degrees and only 4% at 90 degrees. It was suggested that accurate sizing and fitting as well as attention to correct hinge placement relative to the femoral condyles can limit brace migration and improve its effectiveness in mid and deep knee flexion. With using adaptive limb fittings, through flexible pads, and a polycentric joint a more significant improvement of the overall brace performance and efficacy might be obtained. Key points Functional bracing improves the knee joint stability mostly in extension posture. Unlike the non-braced condition, the least knee joint stability appears in mid and deep flexion angles when using a hinged brace. Accurate sizing and fitting and attention to correct hinge placement relative to the femoral condyles can limit brace migration and improve its effectiveness in mid and deep knee flexion. The overall brace performance and efficacy might be improved significantly using adaptive limb fittings through flexible pads and/or polycentric joints. PMID:24149533

The biomechanical effect of increased valgus on total knee arthroplasty: a cadaveric study.

PubMed

Bryant, Brandon J; Tilan, Justin U; McGarry, Michelle H; Takenaka, Nobuyuki; Kim, William C; Lee, Thay Q

2014-04-01

The effects of valgus load on cadaveric knees following total knee arthroplasty (TKA) were investigated using a custom testing system. TKAs were performed on 8 cadaveric knees and tested at 0°, 30°, and 60° knee flexion in both neutral and 5° valgus. Fuji pressure sensitive film was used to quantify contact areas and pressures and MCL strain was determined using a Microscribe digitizing system. Lateral tibiofemoral pressures increased (P < 0.05) at all knee flexion angles with valgus loading. Patellofemoral contact characteristics did not change significantly (P > 0.05). Significant increases in strain were observed along the anterior and posterior border of the MCL at all knee flexion angles. These findings suggest that valgus loading increases TKA joint contact pressures and MCL strain with increasing knee flexion which may increase implant instability. © 2014.

Factors affecting the achievement of Japanese-style deep knee flexion after total knee arthroplasty using posterior-stabilized prosthesis with high-flex knee design.

PubMed

Niki, Yasuo; Takeda, Yuki; Harato, Kengo; Suda, Yasunori

2015-11-01

Achievement of very deep knee flexion after total knee arthroplasty (TKA) can play a critical role in the satisfaction of patients who demand a floor-sitting lifestyle and engage in high-flexion daily activities (e.g., seiza-sitting). Seiza-sitting is characterized by the knees flexed >145º and feet turned sole upwards underneath the buttocks with the tibia internally rotated. The present study investigated factors affecting the achievement of seiza-sitting after TKA using posterior-stabilized total knee prosthesis with high-flex knee design. Subjects comprised 32 patients who underwent TKA with high-flex knee prosthesis and achieved seiza-sitting (knee flexion >145º) postoperatively. Another 32 patients served as controls who were capable of knee flexion >145º preoperatively, but failed to achieve seiza-sitting postoperatively. Accuracy of femoral and tibial component positions was assessed in terms of deviation from the ideal position using a two-dimensional to three-dimensional matching technique. Accuracies of the component position, posterior condylar offset ratio and intraoperative gap length were compared between the two groups. The proportion of patients with >3º internally rotated tibial component was significantly higher in patients who failed at seiza-sitting (41 %) than among patients who achieved it (13 %, p = 0.021). Comparison of intraoperative gap length between patient groups revealed that gap length at 135º flexion was significantly larger in patients who achieved seiza-sitting (4.2 ± 0.4 mm) than in patients who failed at it (2.7 ± 0.4 mm, p = 0.007). Conversely, no significant differences in gap inclination were seen between the groups. From the perspective of surgical factors, accurate implant positioning, particularly rotational alignment of the tibial component, and maintenance of a sufficient joint gap at 135º flexion appear to represent critical factors for achieving >145º of deep knee flexion after TKA.

Identification of types of landings after blocking in volleyball associated with risk of ACL injury.

PubMed

Zahradnik, David; Jandacka, Daniel; Farana, Roman; Uchytil, Jaroslav; Hamill, Joseph

2017-03-01

Landing with a low knee flexion angle after volleyball block jumps may be associated with an increased risk of anterior cruciate ligament (ACL) injury. The aim of the present study was to identify the types of volleyball landings after blocks where the knee flexion angle is found to be under a critical knee flexion angle value of 30° at the instant of the first peak of the ground reaction force (GRF). Synchronized kinematic and kinetic data were collected for each trial. T-tests were used to determine if each knee flexion angle at the instant of the peak GRF was significantly different from the critical value of 30°. A repeated measures ANOVA was used to compare knee flexion angle, time to first peak and the magnitude of the first peak of the resultant GRF and knee stiffness. Significantly lower knee flexion angles were found in the "go" landing (p = .01, ES = 0.6) and the "reverse" landing (p = .02, ES = 0.6) only. The results for knee flexion angle and GRF parameters indicated a significant difference between a "reverse" and "go" and other types of landings, except the "side stick" landing for GRF. The "reverse" and "go" landings may present a risk for ACL injury due to the single-leg landing of these activities that have an associated mediolateral movement.

Hip and knee effects after implantation of a drop foot stimulator.

PubMed

Yao, Daiwei; Lahner, Matthias; Jakubowitz, Eike; Thomann, Anna; Ettinger, Sarah; Noll, Yvonne; Stukenborg-Colsman, Christina; Daniilidis, Kiriakos

2017-01-01

An active ankle dorsiflexion is essential for a proper gait pattern. If there is a failure of the foot lifting, considerable impairments occur. The therapeutic effect of an implantable peroneus nerve stimulator (iPNS) for the ankle dorsiflexion is already approved by recent studies. However, possible affection for knee and hip motion after implantation of an iPNS is not well described. The objective of this retrospective study was to examine with a patient cohort whether the use of iPNS induces a lower-extremity flexion withdrawal response in the form of an increased knee and hip flexion during swing phase. Eighteen subjects (12 m/6 w) treated with an iPNS (ActiGait®, Otto Bock, Duderstadt, Germany) were examined in knee and hip motion by gait analysis with motion capture system (Vicon Motion System Ltd®, Oxford, UK) and Plug-in-Gait model after a mean follow up from 12.5 months. The data were evaluated and compared in activated and deactivated iPNS. Only little changes could be documented, as a slight average improvement in peak knee flexion during stand phase from 1.0° to 2.5° and peak hip flexion in stance from 3.1° to 2.1° In contrast, peak knee flexion during swing appeared similar (25.3° to 25.7°) same as peak hip flexion during swing. In comparison with the healthy extremity, a more symmetric course of the knee flexion during stand phase could be shown. No statistical significant improvements or changes in hip and knee joint could be shown in this study. Only a more symmetric knee flexion during stand phase and a less hip flexion during stand phase might be hints for a positive affection of iPNS for knee and hip joint. It seems that the positive effect of iPNS is only based on the improvement in ankle dorsiflexion according to the recent literature.

Continuous passive motion with accelerated flexion after total knee arthroplasty.

PubMed

Yashar, A A; Venn-Watson, E; Welsh, T; Colwell, C W; Lotke, P

1997-12-01

The use of continuous passive motion after total knee arthroplasty remains controversial. A new approach, starting continuous passive motion at 70 degrees to 100 degrees flexion in the recovery room (Group I) was evaluated. A randomized, prospective study of 210 consecutive total knee arthroplasties was performed at two institutions. The control population (Group II) started continuous passive motion at 0 degree to 30 degrees, and progressed toward 100 degrees flexion. Flexion at postoperative Day 3 (Group I = 82.5 degrees, Group II = 72.8 degrees), and at discharge (Group I = 89.1 degrees, Group II = 84.3 degrees) were significantly different. There was no significant difference between the groups at 4 weeks (Group I = 5.0 degrees-104.1 degrees, Group II = 5.6 degrees-102.0 degrees), 6 weeks (Group I = 2.3 degrees-104.8 degrees, Group II = 2.7 degrees-103.6 degrees), 12 weeks (Group I = 1.7 degrees-107.7 degrees, Group II = 4.7 degrees-108.2 degrees), or at 1 year (Group I = 0.5 degree-113.2 degrees, Group II = 1.8 degrees-110.5 degrees). In Group I, wound necrosis developed in one patient that required a gastrocnemius flap. This major complication was caused by a tight dressing, and not necessarily to the accelerated flexion continuous passive motion. This investigation shows that continuous passive motion using accelerated flexion allows increased flexion during the hospital stay without increased risk of complications, pain, or blood loss. This has significant implications for achieving safe, early discharge. However, no difference was found at followup of 4 weeks or greater, and this did not add significantly to the final outcome.

LIMITED HIP AND KNEE FLEXION DURING LANDING IS ASSOCIATED WITH INCREASED FRONTAL PLANE KNEE MOTION AND MOMENTS

PubMed Central

Pollard, Christine D.; Sigward, Susan M.; Powers, Christopher M.

2009-01-01

Background It has been proposed that female athletes who limit knee and hip flexion during athletic tasks rely more on the passive restraints in the frontal plane to deceleration their body center of mass. This biomechanical pattern is thought to increase the risk for anterior cruciate ligament injury. To date, the relationship between sagittal plane kinematics and frontal plane knee motion and moments has not been explored. Methods Subjects consisted of fifty-eight female club soccer players (age range: 11 to 20 years) with no history of knee injury. Kinematics, ground reaction forces, and surface electromyography were collected while each subject performed a drop landing task. Subjects were divided into two groups based on combined sagittal plane knee and hip flexion angles during the deceleration phase of landing (high flexion and low flexion). Findings Subjects in the low flexion group demonstrated increased knee valgus angles (P = 0.02, effect size 0.27), increased knee adductor moments (P = 0.03, effect size 0.24), decreased energy absorption at the knee and hip (P = 0.02, effect size 0.25; and P< 0.001, effect size 0.59), and increased vastus lateralis EMG when compared to subjects in the high flexion group (P = 0.005, effect size 0.35). Interpretation Female athletes with limited sagittal plane motion during landing exhibit a biomechanical profile that may put these individuals at greater risk for anterior cruciate ligament injury. PMID:19913961

Stance controlled knee flexion improves stimulation driven walking after spinal cord injury

PubMed Central

2013-01-01

Background Functional neuromuscular stimulation (FNS) restores walking function after paralysis from spinal cord injury via electrical activation of muscles in a coordinated fashion. Combining FNS with a controllable orthosis to create a hybrid neuroprosthesis (HNP) has the potential to extend walking distance and time by mechanically locking the knee joint during stance to allow knee extensor muscle to rest with stimulation turned off. Recent efforts have focused on creating advanced HNPs which couple joint motion (e.g., hip and knee or knee and ankle) to improve joint coordination during swing phase while maintaining a stiff-leg during stance phase. Methods The goal of this study was to investigate the effects of incorporating stance controlled knee flexion during loading response and pre-swing phases on restored gait. Knee control in the HNP was achieved by a specially designed variable impedance knee mechanism (VIKM). One subject with a T7 level spinal cord injury was enrolled and served as his own control in examining two techniques to restore level over-ground walking: FNS-only (which retained a stiff knee during stance) and VIKM-HNP (which allowed controlled knee motion during stance). The stimulation pattern driving the walking motion remained the same for both techniques; the only difference was that knee extensor stimulation was constant during stance with FNS-only and modulated together with the VIKM to control knee motion during stance with VIKM-HNP. Results Stance phase knee angle was more natural during VIKM-HNP gait while knee hyperextension persisted during stiff-legged FNS-only walking. During loading response phase, vertical ground reaction force was less impulsive and instantaneous gait speed was increased with VIKM-HNP, suggesting that knee flexion assisted in weight transfer to the leading limb. Enhanced knee flexion during pre-swing phase also aided flexion during swing, especially when response to stimulation was compromised. Conclusions These results show the potential advantages of incorporating stance controlled knee flexion into a hybrid neuroprosthesis for walking. The addition of such control to FNS driven walking could also enable non-level walking tasks such as uneven terrain, slope navigation and stair descent where controlled knee flexion during weight bearing is critical. PMID:23826711

Knee joint moments during high flexion movements: Timing of peak moments and the effect of safety footwear.

PubMed

Chong, Helen C; Tennant, Liana M; Kingston, David C; Acker, Stacey M

2017-03-01

(1) Characterize knee joint moments and peak knee flexion moment timing during kneeling transitions, with the intent of identifying high-risk postures. (2) Determine whether safety footwear worn by kneeling workers (construction workers, tile setters, masons, roofers) alters high flexion kneeling mechanics. Fifteen males performed high flexion kneeling transitions. Kinetics and kinematics were analyzed for differences in ascent and descent in the lead and trail legs. Mean±standard deviation peak external knee adduction and flexion moments during transitions ranged from 1.01±0.31 to 2.04±0.66% body weight times height (BW∗Ht) and from 3.33 to 12.6% BW∗Ht respectively. The lead leg experienced significantly higher adduction moments compared to the trail leg during descent, when work boots were worn (interaction, p=0.005). There was a main effect of leg (higher lead vs. trail) on the internal rotation moment in both descent (p=0.0119) and ascent (p=0.0129) phases. Peak external knee adduction moments during transitions did not exceed those exhibited during level walking, thus increased knee adduction moment magnitude is likely not a main factor in the development of knee OA in occupational kneelers. Additionally, work boots only significantly increased the adduction moment in the lead leg during descent. In cases where one knee is painful, diseased, or injured, the unaffected knee should be used as the lead leg during asymmetric bilateral kneeling. Peak flexion moments occurred at flexion angles above the maximum flexion angle exhibited during walking (approximately 60°), supporting the theory that the loading of atypical surfaces may aid disease development or progression. Copyright © 2016 Elsevier B.V. All rights reserved.

Immediate effect of Masai Barefoot Technology shoes on knee joint moments in women with knee osteoarthritis.

PubMed

Tateuchi, Hiroshige; Taniguchi, Masashi; Takagi, Yui; Goto, Yusuke; Otsuka, Naoki; Koyama, Yumiko; Kobayashi, Masashi; Ichihashi, Noriaki

2014-01-01

Footwear modification can beneficially alter knee loading in patients with knee osteoarthritis. This study evaluated the effect of Masai Barefoot Technology shoes on reductions in external knee moments in patients with knee osteoarthritis. Three-dimensional motion analysis was used to examine the effect of Masai Barefoot Technology versus control shoes on the knee adduction and flexion moments in 17 women (mean age, 63.6 years) with radiographically confirmed knee osteoarthritis. The lateral and anterior trunk lean values, knee flexion and adduction angles, and ground reaction force were also evaluated. The influence of the original walking pattern on the changes in knee moments with Masai Barefoot Technology shoes was evaluated. The knee flexion moment in early stance was significantly reduced while walking with the Masai Barefoot Technology shoes (0.25±0.14Nm/kgm) as compared with walking with control shoes (0.30±0.19 Nm/kgm); whereas the knee adduction moment showed no changes. Masai Barefoot Technology shoes did not increase compensatory lateral and anterior trunk lean. The degree of knee flexion moment in the original walking pattern with control shoes was correlated directly with its reduction when wearing Masai Barefoot Technology shoes by multiple linear regression analysis (adjusted R2=0.44, P<0.01). Masai Barefoot Technology shoes reduced the knee flexion moment during walking without increasing the compensatory trunk lean and may therefore reduce external knee loading in women with knee osteoarthritis. Copyright © 2014 Elsevier B.V. All rights reserved.

[Research progress of larger flexion gap than extension gap in total knee arthroplasty].

PubMed

Zhang, Weisong; Hao, Dingjun

2017-05-01

To summarize the progress of larger flexion gap than extension gap in total knee arthro-plasty (TKA). The domestic and foreign related literature about larger flexion gap than extension gap in TKA, and its impact factors, biomechanical and kinematic features, and clinical results were summarized. During TKA, to adjust the relations of flexion gap and extension gap is one of the key factors of successful operation. The biomechanical, kinematic, and clinical researches show that properly larger flexion gap than extension gap can improve both the postoperative knee range of motion and the satisfaction of patients, but does not affect the stability of the knee joint. However, there are also contrary findings. So adjustment of flexion gap and extension gap during TKA is still in dispute. Larger flexion gap than extension gap in TKA is a new joint space theory, and long-term clinical efficacy, operation skills, and related complications still need further study.

Eliminating impingement optimizes patellar biomechanics in high knee flexion.

PubMed

Tang, Qi-heng; Zhou, Yi-xin; Tang, Jing; Shao, Hong-yi; Wang, Guang-zhi

2010-08-01

We investigated the impact of eliminating the impingement between extensor mechanism and tibial insert on patellar tracking and patellar ligament tension in high knee flexion. Six cadaveric specimens were tested on an Oxford-type testing rig. The Genesis II knee system was implanted into each specimen knee with the traditional tibial insert and high-flex insert successively. Compared to traditional insert, the high-flex insert was characterized with a chambered anterior post and a chambered anterior lip which eliminates patella-post and patellar ligament-anterior lip impingements. The patella was tracked with an NDI Optotrak Certus system. The patellar ligament tension was measured using a NKB S-type tension transducer. There was a decrease of resultant patellar translation relative to the femur with statistically significant (P<0.05) at 90 degrees to 150 degrees of knee flexion and a decrease of patellar ligament tension with statistical significance (P<0.05) at 100 degrees, 120 degrees, 130 degrees, and 140 degrees of flexion using high-flex insert compared to traditional insert. Eliminating the impingement between extensor mechanism and implant in high knee flexion altered patellar tracking and reduced patellar ligament tension, which would facilitate high knee flexion.

Compressive tibiofemoral force during crouch gait.

PubMed

Steele, Katherine M; Demers, Matthew S; Schwartz, Michael H; Delp, Scott L

2012-04-01

Crouch gait, a common walking pattern in individuals with cerebral palsy, is characterized by excessive flexion of the hip and knee. Many subjects with crouch gait experience knee pain, perhaps because of elevated muscle forces and joint loading. The goal of this study was to examine how muscle forces and compressive tibiofemoral force change with the increasing knee flexion associated with crouch gait. Muscle forces and tibiofemoral force were estimated for three unimpaired children and nine children with cerebral palsy who walked with varying degrees of knee flexion. We scaled a generic musculoskeletal model to each subject and used the model to estimate muscle forces and compressive tibiofemoral forces during walking. Mild crouch gait (minimum knee flexion 20-35°) produced a peak compressive tibiofemoral force similar to unimpaired walking; however, severe crouch gait (minimum knee flexion>50°) increased the peak force to greater than 6 times body-weight, more than double the load experienced during unimpaired gait. This increase in compressive tibiofemoral force was primarily due to increases in quadriceps force during crouch gait, which increased quadratically with average stance phase knee flexion (i.e., crouch severity). Increased quadriceps force contributes to larger tibiofemoral and patellofemoral loading which may contribute to knee pain in individuals with crouch gait. Copyright © 2011 Elsevier B.V. All rights reserved.

Osteoarthritis of the patella, lateral femoral condyle and posterior medial femoral condyle correlate with range of motion.

PubMed

Suzuki, Takashi; Motojima, Sayaka; Saito, Shu; Ishii, Takao; Ryu, Keinosuke; Ryu, Junnosuke; Tokuhashi, Yasuaki

2013-11-01

The type of osteoarthritis and the degree of severity which causes restriction of knee range of motion (ROM) is still largely unknown. The objective of this study was to analyse the location and the degree of cartilage degeneration that affect knee range of motion and the connection, if any, between femorotibial angle (FTA) and knee ROM restriction. Four hundreds and fifty-six knees in 230 subjects with knee osteoarthritis undergoing knee arthroplasty were included. Articular surface was divided into eight sections, and cartilage degeneration was evaluated macroscopically during the operation. Cartilage degeneration was classified into four grades based on the degree of exposure of subchondral bone. A Pearson correlation was conducted between FTA and knee flexion angle to determine whether high a degree of FTA caused knee flexion restriction. A logistic regression analysis was also conducted to detect the locations and levels of cartilage degeneration causing knee flexion restriction. No correlation was found between FTA and flexion angle (r = -0.08). Flexion angle was not restricted with increasing FTA. Logistic regression analysis showed significant correlation between restricted knee ROM and levels of knee cartilage degeneration in the patella (odds ratio (OR) = 1.77; P = 0.01), the lateral femoral condyle (OR = 1.62; P = 0.03) and the posterior medial femoral condyle (OR = 1.80; P = 0.03). For clinical relevance, soft tissue release and osteophyte resection around the patella, lateral femoral condyle and posterior medial femoral condyle might be indicated to obtain a higher degree of knee flexion angle.

Relative variances of the cadence frequency of cycling under two differential saddle heights

PubMed Central

Chang, Wen-Dien; Fan Chiang, Chin-Yun; Lai, Ping-Tung; Lee, Chia-Lun; Fang, Sz-Ming

2016-01-01

[Purpose] Bicycle saddle height is a critical factor for cycling performance and injury prevention. The present study compared the variance in cadence frequency after exercise fatigue between saddle heights with 25° and 35° knee flexion. [Methods] Two saddle heights, which were determined by setting the pedal at the bottom dead point with 35° and 25° knee flexion, were used for testing. The relative variances of the cadence frequency were calculated at the end of a 5-minute warm-up period and 5 minutes after inducing exercise fatigue. Comparison of the absolute values of the cadence frequency under the two saddle heights revealed a difference in pedaling efficiency. [Results] Five minutes after inducing exercise fatigue, the relative variances of the cadence frequency for the saddle height with 35° knee flexion was higher than that for the saddle height with 25° knee flexion. [Conclusion] The current finding demonstrated that a saddle height with 25° knee flexion is more appropriate for cyclists than a saddle height with 35° knee flexion. PMID:27065522

Estimating the Mechanical Behavior of the Knee Joint during Crouch Gait: Implications for Real-Time Motor Control of Robotic Knee Orthoses

PubMed Central

Damiano, Diane L.; Bulea, Thomas C.

2016-01-01

Individuals with cerebral palsy frequently exhibit crouch gait, a pathological walking pattern characterized by excessive knee flexion. Knowledge of the knee joint moment during crouch gait is necessary for the design and control of assistive devices used for treatment. Our goal was to 1) develop statistical models to estimate knee joint moment extrema and dynamic stiffness during crouch gait, and 2) use the models to estimate the instantaneous joint moment during weight-acceptance. We retrospectively computed knee moments from 10 children with crouch gait and used stepwise linear regression to develop statistical models describing the knee moment features. The models explained at least 90% of the response value variability: peak moment in early (99%) and late (90%) stance, and dynamic stiffness of weight-acceptance flexion (94%) and extension (98%). We estimated knee extensor moment profiles from the predicted dynamic stiffness and instantaneous knee angle. This approach captured the timing and shape of the computed moment (root-mean-squared error: 2.64 Nm); including the predicted early-stance peak moment as a correction factor improved model performance (root-mean-squared error: 1.37 Nm). Our strategy provides a practical, accurate method to estimate the knee moment during crouch gait, and could be used for real-time, adaptive control of robotic orthoses. PMID:27101612

Sex differences in lower extremity biomechanics during single leg landings.

PubMed

Schmitz, Randy J; Kulas, Anthony S; Perrin, David H; Riemann, Bryan L; Shultz, Sandra J

2007-07-01

Females have an increased incident rate of anterior cruciate ligament tears compared to males. Biomechanical strategies to decelerate the body in the vertical direction have been implicated as a contributing cause. This study determined if females would exhibit single leg landing strategies characterized by decreased amounts of hip, knee, and ankle flexion resulting in greater vertical ground reaction forces and altered energy absorption patterns when compared to males. Recreationally active males (N=14) and females (N=14), completed five single leg landings from a 0.3m height onto a force platform while three-dimensional kinematics and kinetics were simultaneously collected. Compared to males, females exhibited (1) less total hip and knee flexion displacements (40% and 64% of males, respectively, P<0.05) and less time to peak hip and knee flexion (48% and 78% of males, respectively, P<0.05), (2) 9% greater peak vertical ground reaction forces (P<0.05), (3) less total lower body energy absorption (76% of males, P<0.05), and (4) 11% greater relative energy absorption at the ankle (P<0.05). Females in this study appear to adopt a single leg landing style using less hip and knee flexion, absorbing less total lower body energy with more relative energy at the ankle resulting in a landing style that can be described as stiff. This may potentially cause increased demands on non-contractile components of the lower extremity. Preventative training programs designed to prevent knee injury may benefit from the biomechanical description of sex-specific landing methods demonstrated by females in this study by focusing on the promotion of more reliance on using the contractile components to absorb impact energy during landings.

Spontaneous Improvement of Compensatory Knee Flexion After Surgical Correction of Mismatch Between Pelvic Incidence and Lumbar Lordosis.

PubMed

Cheng, Xiaofei; Zhang, Feng; Wu, Jigong; Zhu, Zhenan; Dai, Kerong; Zhao, Jie

2016-08-15

A retrospective study. The aim of this study was to investigate the correlation between pelvic incidence (PI) and lumbar lordosis (LL) mismatch and knee flexion during standing in patients with lumbar degenerative diseases and to examine the effects of surgical correction of the PI-LL mismatch on knee flexion. Only several studies focused on knee flexion as a compensatory mechanism of the PI-LL mismatch. Little information is currently available on the effects of lumbar correction on knee flexion in patients with the PI-LL mismatch. A group of patients with lumbar degenerative diseases were divided into PI-LL match group (PI-LL ≤ 10°) and PI-LL mismatch group (PI-LL > 10°). A series of radiographic parameters and knee flexion angle (KFA) were compared between the two groups. The PI-LL mismatch group was further subdivided into operative and nonoperative group. The changes in KFA with PI-LL were examined. The PI-LL mismatch group exhibited significantly greater sagittal vertical axis (SVA), pelvic tilt (PT) and KFA, and smaller LL, thoracic kyphosis (TK), and sacral slope than the PI-LL match group. PI-LL, LL, PI, SVA, and PT were significantly correlated with KFA in the PI-LL mismatch group. From baseline to 6-month follow-up, all variables were significantly different in the operative group with the exception of PI, although there was no significant difference in any variable in the nonoperative group. The magnitude of surgical correction in the PI-LL mismatch was significantly correlated with the degree of spontaneous changes in KFA, PT, and TK. The PI-LL mismatch would contribute to compensatory knee flexion during standing in patients with lumbar degenerative disease. Surgical correction of the PI-LL mismatch could lead to a spontaneous improvement of compensatory knee flexion. The degree of improvement in knee flexion depends in part on the amount of correction in the PI-LL mismatch. 3.

Effect of the Distal Femoral Joint Line on Ligament Tensions in Flexion with Cruciate-Retaining Total Knee Prostheses.

PubMed

Narayanan, Rajkishen; Lenz, Nathaniel; Werner, Jordan Alexander; Cross, Michael B; Hughes, Dean; Laster, Scott; Schwarzkopf, Ran

2018-04-13

Proper ligament tension in knee flexion within cruciate-retaining (CR) total knee arthroplasty has long been associated with clinical success; however, traditional balancing principles have assumed that the distal femoral joint line (DFJL) affects only extension. The purpose of this study was to determine the effect DFJL may have on ligament strains and tibiofemoral kinematics of CR knee designs in flexion. A computational analysis was performed using a musculoskeletal modeling system for two different knee implants, the high-flex CR (HFCR) and guided-motion CR (GMCR). Tibiofemoral kinematics and ligament strain were measured at 90-degree knee flexion while the implants' DFJL was incrementally shifted proximally. Femoral implant position and kinematics were used to determine the femur's anteroposterior position relative to the tibia. The change in the femoral medial condyle position relative to the tibia was 0.33 mm and 0.53 mm more anterior per each 1-mm elevation of the DFJL for HFCR and GMCR, respectively. The change in the lateral condyle position was 0.20 mm more anterior and 0.06 mm more posterior for HFCR and GMCR, respectively. The strain in the lateral and medial collateral ligaments changed minimally with elevation of the DFJL. In both implants, strain increased in the anterior lateral and posterior medial bundles of the posterior collateral ligament with elevation of the DFJL, whereas strain decreased in the iliotibial band and iliotibial patellar band. Our findings suggest that DFJL affects ligament tension at 90-degree knee flexion and therefore flexion balance for CR implants. Elevating the DFJL to address tight extension space in a CR knee while flexion space is well balanced could result in increased flexion tension especially when the flexion-extension mismatch is large. To achieve balanced flexion and extension, the amount of DFJL elevation may need to be reduced. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Can in vitro systems capture the characteristic differences between the flexion-extension kinematics of the healthy and TKA knee?

PubMed

Varadarajan, Kartik M; Harry, Rubash E; Johnson, Todd; Li, Guoan

2009-10-01

In vitro systems provide a powerful means to evaluate the efficacy of total knee arthroplasty (TKA) in restoring normal knee kinematics. The Oxford knee rig (OKR) and the robotic knee testing system (RKTS) represent two systems that have been extensively used to study TKA biomechanics. Nonetheless, a frequently asked question is whether in vitro simulations can capture the in vivo behavior of the knee. Here, we compared the flexion-extension kinematics of intact knees and knees after TKA tested on the OKR and RKTS, to results of representative in vivo studies. The goal was to determine if the in vitro systems could capture the key kinematic features of knees in healthy subjects and TKA patients. Results showed that the RKTS and the OKR can replicate the femoral rollback and 'screw home' tibial rotation between 0 degrees and 30 degrees flexion seen in healthy subjects, and the reduced femoral rollback and absence of 'screw home' motion in TKA patients. The RKTS also replicated the overall internally rotated position of the tibia beyond 30 degrees flexion. However, ability of the OKR to replicate the internally rotated position of the knee beyond 30 degrees flexion was inconsistent. These data could aid in validation of new in vitro systems and physiologic interpretations of in vitro results.

Native Knee Laxities at 0°, 45°, and 90° of Flexion and Their Relationship to the Goal of the Gap-Balancing Alignment Method of Total Knee Arthroplasty.

PubMed

Roth, Joshua D; Howell, Stephen M; Hull, Maury L

2015-10-21

Gap-balancing is an alignment method for total knee arthroplasty with the goal of creating uniform tension in the periarticular soft-tissue restraints and equal laxities throughout the arc of flexion. However, there is little evidence that achieving equal laxities prevents either overly tight or overly loose soft-tissue restraints after total knee arthroplasty. Accordingly, the purpose of the present study was to determine whether the laxities at 0°, 45°, and 90° of flexion are equal in the native knee. Seven different laxities were measured at 0°, 45°, and 90° of flexion in ten fresh-frozen native cadaveric knees (with intact menisci, cartilage, and ligaments) by applying loads of ±5 Nm in varus-valgus rotation, ±3 Nm in internal-external rotation, 100 N in distraction, and ±45 N in anterior-posterior translation with use of a six-degrees-of-freedom load application system. The mean laxities (and standard deviations) at 45° of flexion were 1.7° ± 0.6° greater in varus, 0.9° ± 0.4° greater in valgus, 10.2° ± 2.7° greater in internal rotation, 10.1° ± 2.0° greater in external rotation, 1.7 ± 1.0 mm greater in distraction translation, and 3.3 ± 1.5 mm greater in anterior translation than those at 0° of flexion. The mean laxities at 90° of flexion were 2.5° ± 0.8° greater in varus, 1.0° ± 0.5° greater in valgus, 10.0° ± 4.6° greater in internal rotation, 10.1° ± 4.5° greater in external rotation, 1.8 ± 0.7 mm greater in distraction, and 1.6 ± 1.2 mm greater in anterior translation than those at 0° of flexion. The mean anterior translation at 90° of flexion was 1.7 ± 0.9 mm less than that at 45° of flexion. Because five of the seven laxities were at least 1.7° or 1.6 mm greater at both 45° and 90° of flexion than those at 0° of flexion, the laxities of the native knee measured in this study are unequal at these flexion angles and therefore do not support the goal of gap-balancing in total knee arthroplasty. One possible disadvantage of changing the native laxities at 45° and 90° of flexion to match those at 0° of flexion in a total knee arthroplasty is the overly tight soft-tissue restraints relative to those of the native knee, which patients may perceive as pain, stiffness, and/or limited flexion. Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.

A Highly Backdrivable, Lightweight Knee Actuator for Investigating Gait in Stroke

PubMed Central

Sulzer, James S.; Roiz, Ronald A.; Peshkin, Michael A.; Patton, James L.

2012-01-01

Many of those who survive a stroke develop a gait disability known as stiff-knee gait (SKG). Characterized by reduced knee flexion angle during swing, people with SKG walk with poor energy efficiency and asymmetry due to the compensatory mechanisms required to clear the foot. Previous modeling studies have shown that knee flexion activity directly before the foot leaves the ground, and this should result in improved knee flexion angle during swing. The goal of this research is to physically test this hypothesis using robotic intervention. We developed a device that is capable of assisting knee flexion torque before swing but feels imperceptible (transparent) for the rest of the gait cycle. This device uses sheathed Bowden cable to control the deflection of a compliant torsional spring in a configuration known as a Series Elastic Remote Knee Actuator (SERKA). In this investigation, we describe the design and evaluation of SERKA, which includes a pilot experiment on stroke subjects. SERKA could supply a substantial torque (12 N· m) in less than 20 ms, with a maximum torque of 41 N·m. The device resisted knee flexion imperceptibly when desired, at less than 1 N·m rms torque during normal gait. With the remote location of the actuator, the user experiences a mass of only 1.2 kg on the knee. We found that the device was capable of increasing both peak knee flexion angle and velocity during gait in stroke subjects. Thus, the SERKA is a valid experimental device that selectively alters knee kinetics and kinematics in gait after stroke. PMID:22563305

Significant effect of the posterior tibial slope and medial/lateral ligament balance on knee flexion in total knee arthroplasty.

PubMed

Fujimoto, Eisaku; Sasashige, Yoshiaki; Masuda, Yasuji; Hisatome, Takashi; Eguchi, Akio; Masuda, Tetsuo; Sawa, Mikiya; Nagata, Yoshinori

2013-12-01

The intra-operative femorotibial joint gap and ligament balance, the predictors affecting these gaps and their balances, as well as the postoperative knee flexion, were examined. These factors were assessed radiographically after a posterior cruciate-retaining total knee arthroplasty (TKA). The posterior condylar offset and posterior tibial slope have been reported as the most important intra-operative factors affecting cruciate-retaining-type TKAs. The joint gap and balance have not been investigated in assessments of the posterior condylar offset and the posterior tibial slope. The femorotibial gap and medial/lateral ligament balance were measured with an offset-type tensor. The femorotibial gaps were measured at 0°, 45°, 90° and 135° of knee flexion, and various gap changes were calculated at 0°-90° and 0°-135°. Cruciate-retaining-type arthroplasties were performed in 98 knees with varus osteoarthritis. The 0°-90° femorotibial gap change was strongly affected by the posterior condylar offset value (postoperative posterior condylar offset subtracted by the preoperative posterior condylar offset). The 0°-135° femorotibial gap change was significantly correlated with the posterior tibial slope and the 135° medial/lateral ligament balance. The postoperative flexion angle was positively correlated with the preoperative flexion angle, γ angle and the posterior tibial slope. Multiple-regression analysis demonstrated that the preoperative flexion angle, γ angle, posterior tibial slope and 90° medial/lateral ligament balance were significant independent factors for the postoperative knee flexion angle. The flexion angle change (postoperative flexion angle subtracted by the preoperative flexion angle) was also strongly correlated with the preoperative flexion angle, posterior tibial slope and 90° medial/lateral ligament balance. The postoperative flexion angle is affected by multiple factors, especially in cruciate-retaining-type TKAs. However, it is important to pay attention not only to the posterior tibial slope, but also to the flexion medial/lateral ligament balance during surgery. A cruciate-retaining-type TKA has the potential to achieve both stability and a wide range of motion and to improve the patients' activities of daily living.

Knee rotation influences the femoral tunnel angle measurement after anterior cruciate ligament reconstruction: a 3-dimensional computed tomography model study

PubMed Central

Tang, Jing; Thorhauer, Eric; Marsh, Chelsea; Fu, Freddie H.

2013-01-01

Purpose Femoral tunnel angle (FTA) has been proposed as a metric for evaluating whether ACL reconstruction was performed anatomically. In clinic, radiographic images are typically acquired with an uncertain amount of internal/external knee rotation. The extent to which knee rotation will influence FTA measurement is unclear. Furthermore, differences in FTA measurement between the two common positions (0° and 45° knee flexion) have not been established. The purpose of this study was to investigate the influence of knee rotation on FTA measurement after ACL reconstruction. Methods Knee CT data from 16 subjects were segmented to produce 3D bone models. Central axes of tunnels were identified. The 0° and 45° flexion angles were simulated. Knee internal/external rotations were simulated in a range of ±20°. FTA was defined as the angle between the tunnel axis and femoral shaft axis, orthogonally projected into the coronal plane. Results Femoral tunnel angle was positively/negatively correlated with knee rotation angle at 0°/45° knee flexion. At 0° knee flexion, FTA for anterio-medial (AM) tunnels was significantly decreased at 20° of external knee rotation. At 45° knee flexion, more than 16° external or 19° internal rotation significantly altered FTA measurements for single-bundle tunnels; smaller rotations (±9° for AM, ±5° for PL) created significant errors in FTA measurements after double-bundle reconstruction. Conclusion Femoral tunnel angle measurements were correlated with knee rotation. Relatively small imaging malalignment introduced significant errors with knee flexed 45°. This study supports using the 0° flexion position for knee radiographs to reduce errors in FTA measurement due to knee internal/external rotation. Level of evidence Case–control study, Level III. PMID:23589127

The effect of posterior tibial slope on knee flexion in posterior-stabilized total knee arthroplasty.

PubMed

Shi, Xiaojun; Shen, Bin; Kang, Pengde; Yang, Jing; Zhou, Zongke; Pei, Fuxing

2013-12-01

To evaluate and quantify the effect of the tibial slope on the postoperative maximal knee flexion and stability in the posterior-stabilized total knee arthroplasty (TKA). Fifty-six patients (65 knees) who had undergone TKA with the posterior-stabilized prostheses were divided into the following 3 groups according to the measured tibial slopes: Group 1: ≤4°, Group 2: 4°-7° and Group 3: >7°. The preoperative range of the motion, the change in the posterior condylar offset, the elevation of the joint line, the postoperative tibiofemoral angle and the preoperative and postoperative Hospital for Special Surgery (HSS) scores were recorded. The tibial anteroposterior translation was measured using the Kneelax 3 Arthrometer at both the 30° and the 90° flexion angles. The mean values of the postoperative maximal knee flexion were 101° (SD 5), 106° (SD 5) and 113° (SD 9) in Groups 1, 2 and 3, respectively. A significant difference was found in the postoperative maximal flexion between the 3 groups (P < 0.001). However, no significant differences were found between the 3 groups in the postoperative HSS scores, the changes in the posterior condylar offset, the elevation of the joint line or the tibial anteroposterior translation at either the 30° or the 90° flexion angles. A 1° increase in the tibial slope resulted in a 1.8° flexion increment (r = 1.8, R (2) = 0.463, P < 0.001). An increase in the posterior tibial slope can significantly increase the postoperative maximal knee flexion. The tibial slope with an appropriate flexion and extension gap balance during the operation does not affect the joint stability.

Differences in knee flexion between the Genium and C-Leg microprocessor knees while walking on level ground and ramps.

PubMed

Lura, Derek J; Wernke, Matthew M; Carey, Stephanie L; Kahle, Jason T; Miro, Rebecca M; Highsmith, M Jason

2015-02-01

Microprocessor knees have improved the gait and functional abilities of persons with transfemoral amputation. The Genium prosthetic knee offers an advanced sensor and control system designed to decrease impairment by: allowing greater stance phase flexion, easing transitions between gait phases, and compensating for changes in terrain. The aim of this study was to determine differences between the knee flexion angle of persons using the Genium knee, the C-Leg knee, and non-amputee controls; and to evaluate the impact the prostheses on gait and level of impairment of the user. This study used a randomized experimental crossover of persons with transfemoral amputation using the Genium and C-Leg microprocessor knees (n=25), with an observational sample of non-amputee controls (n=5). Gait analysis by 3D motion tracking of subjects ambulating at different speeds on level ground and on 5° and 10° ramps was completed. Use of the Genium resulted in a significant increase in peak knee flexion for swing (5°, p<0.01, d=0.34) and stance (2°, p<0.01, d=0.19) phases relative to C-Leg use. There was a high degree of variability between subjects, and significant differences still remain between the Genium group and the control group's knee flexion angles for most speeds and slopes. The Genium knee generally increases flexion in swing and stance, potentially decreasing the level of impairment for persons with transfemoral amputation. This study demonstrates functional differences between the C-Leg and Genium knees to help prosthetists determine if the Genium will provide functional benefits to individual patients. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Textile-Based Wearable Sensing Device Designed for Monitoring the Flexion Angle of Elbow and Knee Movements

PubMed Central

Shyr, Tien-Wei; Shie, Jing-Wen; Jiang, Chang-Han; Li, Jung-Jen

2014-01-01

In this work a wearable gesture sensing device consisting of a textile strain sensor, using elastic conductive webbing, was designed for monitoring the flexion angle of elbow and knee movements. The elastic conductive webbing shows a linear response of resistance to the flexion angle. The wearable gesture sensing device was calibrated and then the flexion angle-resistance equation was established using an assembled gesture sensing apparatus with a variable resistor and a protractor. The proposed device successfully monitored the flexion angle during elbow and knee movements. PMID:24577526

Sagittal Plane Hip, Knee, and Ankle Biomechanics and the Risk of Anterior Cruciate Ligament Injury: A Prospective Study

PubMed Central

Leppänen, Mari; Pasanen, Kati; Krosshaug, Tron; Kannus, Pekka; Vasankari, Tommi; Kujala, Urho M.; Bahr, Roald; Perttunen, Jarmo; Parkkari, Jari

2017-01-01

Background: Stiff landings with less knee flexion and high vertical ground-reaction forces have been shown to be associated with an increased risk of anterior cruciate ligament (ACL) injury. The literature on the association between other sagittal plane measures and the risk of ACL injuries with a prospective study design is lacking. Purpose: To investigate the relationship between selected sagittal plane hip, knee, and ankle biomechanics and the risk of ACL injury in young female team-sport athletes. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 171 female basketball and floorball athletes (age range, 12-21 years) participated in a vertical drop jump test using 3-dimensional motion analysis. All new ACL injuries, as well as match and training exposure data, were recorded for 1 to 3 years. Biomechanical variables, including hip and ankle flexion at initial contact (IC), hip and ankle ranges of motion (ROMs), and peak external knee and hip flexion moments, were selected for analysis. Cox regression models were used to calculate hazard ratios (HRs) with 95% CIs. The combined sensitivity and specificity of significant test variables were assessed using a receiver operating characteristic (ROC) curve analysis. Results: A total of 15 noncontact ACL injuries were recorded during follow-up (0.2 injuries/1000 player-hours). Of the variables investigated, landing with less hip flexion ROM (HR for each 10° increase in hip ROM, 0.61 [95% CI, 0.38-0.99]; P < .05) and a greater knee flexion moment (HR for each 10-N·m increase in knee moment, 1.21 [95% CI, 1.04-1.40]; P = .01) was significantly associated with an increased risk of ACL injury. Hip flexion at IC, ankle flexion at IC, ankle flexion ROM, and peak external hip flexion moment were not significantly associated with the risk of ACL injury. ROC curve analysis for significant variables showed an area under the curve of 0.6, indicating a poor combined sensitivity and specificity of the test. Conclusion: Landing with less hip flexion ROM and a greater peak external knee flexion moment was associated with an increased risk of ACL injury in young female team-sport players. Studies with larger populations are needed to confirm these findings and to determine the role of ankle flexion ROM as a risk factor for ACL injury. Increasing knee and hip flexion ROMs to produce soft landings might reduce knee loading and risk of ACL injury in young female athletes. PMID:29318174

Knee Joint Kinematics and Kinetics During a Lateral False-Step Maneuver

PubMed Central

Golden, Grace M.; Pavol, Michael J.; Hoffman, Mark A.

2009-01-01

Abstract Context: Cutting maneuvers have been implicated as a mechanism of noncontact anterior cruciate ligament (ACL) injuries in collegiate female basketball players. Objective: To investigate knee kinematics and kinetics during running when the width of a single step, relative to the path of travel, was manipulated, a lateral false-step maneuver. Design: Crossover design. Setting: University biomechanics laboratory. Patients or Other Participants: Thirteen female collegiate basketball athletes (age  =  19.7 ± 1.1 years, height  =  172.3 ± 8.3 cm, mass  =  71.8 ± 8.7 kg). Intervention(s): Three conditions: normal straight-ahead running, lateral false step of width 20% of body height, and lateral false step of width 35% of body height. Main Outcome Measure(s): Peak angles and internal moments for knee flexion, extension, abduction, adduction, internal rotation, and external rotation. Results: Differences were noted among conditions in peak knee angles (flexion [P < .01], extension [P  =  .02], abduction [P < .01], and internal rotation [P < .01]) and peak internal knee moments (abduction [P < .01], adduction [P < .01], and internal rotation [P  =  .03]). The lateral false step of width 35% of body height was associated with larger peak flexion, abduction, and internal rotation angles and larger peak abduction, adduction, and internal rotation moments than normal running. Peak flexion and internal rotation angles were also larger for the lateral false step of width 20% of body height than for normal running, whereas peak extension angle was smaller. Peak internal rotation angle increased progressively with increasing step width. Conclusions: Performing a lateral false-step maneuver resulted in changes in knee kinematics and kinetics compared with normal running. The differences observed for lateral false steps were consistent with proposed mechanisms of ACL loading, suggesting that lateral false steps represent a hitherto neglected mechanism of noncontact ACL injury. PMID:19771289

Anteroposterior Stability of the Knee during the Stance Phase of Gait after Anterior Cruciate Ligament Deficiency

PubMed Central

Chen, CH; Li, JS; Hosseini, A; Gadikota, HR; Gill, TJ; Li, G

2011-01-01

Quadriceps avoidance and higher flexion strategy have been assumed as effects of ACL deficiency on knee joint function during gait. However, the effect of ACL deficiency on anteroposterior stability of the knee during gait is not well defined. In this study, ten patients with unilateral acute ACL ruptures and the contralateral side intact performed gait on a treadmill. Flexion angles and anteroposterior translation of the ACL injured and the intact controlateral knees were measured at every 10% of the stance phase of the gait (from heel strike to toe-off) using a combined MRI and dual fluoroscopic image system (DFIS). The data indicated that during the stance phase of the gait, the ACL-deficient knees showed higher flexion angles compared to the intact contralateral side, consistent with the assumption of a higher flexion gait strategy. However, the data also revealed that the ACL-deficient knees had higher anterior tibial translation compared to the intact contralateral side during the stance phase of the gait. The higher flexion gait strategy was not shown to correlate to a reduction of the anterior tibial translation in ACL deficient knees. These data may provide indications for conservative treatment or surgical reconstruction of the ACL injured knees in restoration of the knee kinematics during daily walking activities. PMID:22169387

The Effects of Fatigue and Local Carriage on Musculoskeletal Injury Mechanisms

DTIC Science & Technology

2012-09-01

the mean and SD of the pelvis, hip, knee , and ankle angles at heel contact and stance of walking. Table 5 shows the mean and SD of the hip, knee , and...22.9 (8.6) Hip flexion at heel contact (deg) 32.1 (4.3) 28.2 (10.4) 45.4 (5.2) 40.6 (10.9) Knee flexion at heel contact (deg) -2.5 (3.1...1.1 (4.5) 3.9 (3.2) 4.7 (4.9) Maximum knee flexion at stance (deg) 19.0 (2.8) 20.7 (4.4) 24.6 (4.5) 25.0 (5.3) Ankle dorsi-flexion at heel

The role of the deep medial collateral ligament in controlling rotational stability of the knee.

PubMed

Cavaignac, Etienne; Carpentier, Karel; Pailhé, Regis; Luyckx, Thomas; Bellemans, Johan

2015-10-01

The tibial insertion of the deep medial collateral ligament (dMCL) is frequently sacrificed when the proximal tibial cut is performed during total knee arthroplasty. The role of the dMCL in controlling the knee's rotational stability is still controversial. The aim of this study was to quantify the rotational laxity induced by an isolated lesion of the dMCL as it occurs during tibial preparation for knee arthroplasty. An isolated resection of the deep MCL was performed in 10 fresh-frozen cadaver knees. Rotational laxity was measured during application of a standard 5.0 N.m rotational torque. Maximal tibial rotation was measured at different knee flexion angles using an image-guided navigation system (Medivision Surgetics system, Praxim, Grenoble, France) before and after dMCL resection. In all cases, internal and external tibial rotation increased after dMCL resection. Total rotational laxity increased significantly for all knee flexion angles, with an average difference of +7.8° (SD 5.7) with the knee in extension, +8.9° (SD 1.9) in 30° flexion, +7° (SD 2.9) in 60° flexion and +5.3° (SD 2.8) in 90° flexion. Sacrificing the tibial insertion of the deep MCL increases rotational laxity of the knee by 5°-9°, depending on the knee flexion angle. Based on our findings, new surgical techniques and implants that preserve the dMCL insertion such as tibial inlay components should be developed. Further clinical evaluations are necessary.

Kinematic comparison between mobile-bearing and fixed-bearing inserts in NexGen legacy posterior stabilized flex total knee arthroplasty.

PubMed

Shi, Kenrin; Hayashida, Kenji; Umeda, Naoya; Yamamoto, Kengo; Kawai, Hideo

2008-02-01

Femoral component rollback and tibial rotation were evaluated using lateral radiographs taken during passive knee flexion under fluoroscopy in NexGen Legacy Posterior Stabilized Flex (Zimmer, Warsaw, Ind) total knee arthroplasties (TKAs; 30 with mobile insert and 26 with fixed insert). Measured maximal flexion angle demonstrated no significant differences. Femoral component rollback was observed predominantly in TKAs with fixed insert in more than 45 degrees flexion and correlated with maximal flexion angle in each group. Tibial internal rotation was more significant in TKAs with mobile insert in maximal flexion. However, tibial internal rotation from 90 degrees to maximal flexion, which demonstrated correlation with maximal flexion angle in each group, did not show significant difference. The kinematic differences between 2 inserts seemed to have little relevance to the maximal flexion angle.

The Effect of Patellar Thickness on Intraoperative Knee Flexion and Patellar Tracking in Patients With Arthrofibrosis Undergoing Total Knee Arthroplasty.

PubMed

Kim, Abraham D; Shah, Vivek M; Scott, Richard D

2016-05-01

We evaluated the intraoperative effect of patellar thickness on intraoperative passive knee flexion and patellar tracking during total knee arthroplasty (TKA) in patients with preoperative arthrofibrosis and compared them to patients with normal preoperative range of motion (ROM) documented in a prior study. Routine posterior cruciate ligament-retaining TKA was performed in a total of 34 knees, 23 with normal ROM and 11 with arthrofibrosis, defined as ≤100° of passive knee flexion against gravity under anesthesia. Once clinical balance and congruent patellar tracking were established, custom trial patellar components thicker than the standard trial by 2-mm increments (2-8 mm) were sequentially placed and trialed. Passive flexion against gravity was recorded using digital photograph goniometry. Gross mechanics of patellofemoral tracking were visually assessed. On average, passive knee flexion decreased 2° for every 2-mm increment of patellar thickness (P < .0001), which was similar to patients with normal preoperative ROM. In addition, increased patellar thickness had no gross effect on patellar subluxation and tilt in patients with arthrofibrosis as well as those with normal ROM. Patellar thickness had a modest effect on intraoperative passive flexion and no effect on patellar tracking in patients with arthrofibrosis undergoing TKA. There was no marked difference in intraoperative flexion and patellar tracking between patients with arthrofibrosis and patients with normal preoperative ROM. Copyright © 2016 Elsevier Inc. All rights reserved.

The relationship between quadriceps muscle force, knee flexion, and anterior cruciate ligament strain in an in vitro simulated jump landing.

PubMed

Withrow, Thomas J; Huston, Laura J; Wojtys, Edward M; Ashton-Miller, James A

2006-02-01

An instrumented cadaveric knee construct was used to quantify the association between impact force, quadriceps force, knee flexion angle, and anterior cruciate ligament relative strain in simulated unipedal jump landings. Anterior cruciate ligament strain will correlate with impact force, quadriceps force, and knee flexion angle. Descriptive laboratory study. Eleven cadaveric knees (age, 70.8 [19.3] years; 5 male; 6 female) were mounted in a custom fixture with the tibia and femur secured to a triaxial load cell. Quadriceps, hamstring, and gastrocnemius muscle forces were simulated using pretensioned steel cables (stiffness, 7 kN/cm), and the quadriceps tendon force was measured using a load cell. Mean strain on the anteromedial bundle of the anterior cruciate ligament was measured using a DVRT. With the knee in 25 degrees of flexion, the construct was vertically loaded by an impact force initially directed 4 cm posterior to the knee joint center. Tibiofemoral kinematics was measured using a 3D optoelectronic tracking system. The increase in anterior cruciate ligament relative strain was proportional to the increase in quadriceps force (r(2) = 0.74; P < .00001) and knee flexion angle (r(2) = 0.88; P < .00001) but was not correlated with the impact force (r(2) = 0.009; P = .08). The increase in knee flexion and quadriceps force during this simulated 1-footed landing strongly influenced the relative strain on the anteromedial bundle of the anterior cruciate ligament. These results suggest that even in the presence of knee flexor muscle forces, the increase in quadriceps force required to prevent the knee from flexing during landing can place the anterior cruciate ligament at risk for large strains.

Knee Muscular Control During Jump Landing in Multidirections.

PubMed

Sinsurin, Komsak; Vachalathiti, Roongtiwa; Jalayondeja, Wattana; Limroongreungrat, Weerawat

2016-06-01

Jump landing is a complex movement in sports. While competing and practicing, athletes frequently perform multi-planar jump landing. Anticipatory muscle activity could influence the amount of knee flexion and prepare the knee for dynamic weight bearing such as landing tasks. The aim of the present study was to examine knee muscle function and knee flexion excursion as athletes naturally performed multi-direction jump landing. Eighteen male athletes performed the jump-landing test in four directions: forward (0°), 30° diagonal, 60° diagonal, and lateral (90°). Muscles tested were vastus medialis (VM), vastus lateralis (VL), rectus femoris (RF), semitendinosus (ST), and biceps femoris (BF). A Vicon(TM) 612 workstation collected the kinematic data. An electromyography was synchronized with the Vicon(TM) Motion system to quantify dynamic muscle function. Repeated measure ANOVA was used to analyze the data. Jump-landing direction significantly influenced (P < 0.05) muscle activities of VL, RF, and ST and knee flexion excursion. Jumpers landed with a trend of decreasing knee flexion excursion and ST muscle activity 100 ms before foot contact progressively from forward to lateral directions of jump landing. A higher risk of knee injury might occur during lateral jump landing than forward and diagonal directions. Athletes should have more practice in jump landing in lateral direction to avoid injury. Landing technique with high knee flexion in multi-directions should be taught to jumpers for knee injury prevention.

Angular-velocity control approach for stance-control orthoses.

PubMed

Lemaire, Edward D; Goudreau, Louis; Yakimovich, Terris; Kofman, Jonathan

2009-10-01

Currently, stance-control knee orthoses require external control mechanisms to control knee flexion during stance and allow free knee motion during the swing phase of gait. A new angular-velocity control approach that uses a rotary-hydraulic device to resist knee flexion when the knee angular velocity passes a preset threshold is presented. This angular-velocity approach for orthotic stance control is based on the premise that knee-flexion angular velocity during a knee-collapse event, such as a stumble or fall, is greater than that during walking. The new hydraulic knee-flexion control device does not require an external control mechanism to switch from free motion to stance control mode. Functional test results demonstrated that the hydraulic angular-velocity activated knee joint provided free knee motion during walking, engaged upon knee collapse, and supported body weight while the end-user recovered to a safe body position. The joint was tested to 51.6 Nm in single loading tests and passed 200,000 repeated loading cycles with a peak load of 88 Nm per cycle. The hydraulic, angular velocity activation approach has potential to improve safety and security for people with lower extremity weakness or when recovering from joint trauma.

THE BIOMECHANICAL RESPONSE OF PERSONS WITH TRANSFEMORAL AMPUTATION TO VARIATIONS IN PROSTHETIC KNEE ALIGNMENT DURING LEVEL WALKING

PubMed Central

Koehler-McNicholas, Sara R.; Lipschutz, Robert D.; Gard, Steven A.

2017-01-01

Prosthetic alignment is an important factor in the overall fit and performance of a lower-limb prosthesis. However, the association between prosthetic alignment and control strategies used by persons with transfemoral amputation to coordinate the movement of a passive prosthetic knee is poorly understood. This study investigated the biomechanical response of persons with transfemoral amputation to systematic perturbations in knee joint alignment during a level walking task. Quantitative gait data were collected for three alignment conditions: bench alignment, 2 cm anterior knee translation (ANT), and 2 cm posterior knee translation (POST). In response to a destabilizing alignment perturbation (ANT), subjects significantly increased their early-stance hip extension moment, confirming that persons with transfemoral amputation rely on a hip extensor strategy to maintain knee joint stability. However, subjects also decreased the rate at which they loaded their prosthesis, decreased their step length, increased their trunk flexion, and maintained their limb in a more vertical posture at the time of opposite toe off. Collectively, these results suggest that persons with transfemoral amputation rely on a combination of strategies to coordinate stance-phase knee flexion. Further, no significant changes were observed in response to the POST condition, suggesting that a bias toward posterior alignment may have fewer implications in terms of stance-phase, knee-joint control. PMID:28355034

The biomechanical response of persons with transfemoral amputation to variations in prosthetic knee alignment during level walking.

PubMed

Koehler-McNicholas, Sara R; Lipschutz, Robert D; Gard, Steven A

2016-01-01

Prosthetic alignment is an important factor in the overall fit and performance of a lower-limb prosthesis. However, the association between prosthetic alignment and control strategies used by persons with transfemoral amputation to coordinate the movement of a passive prosthetic knee is poorly understood. This study investigated the biomechanical response of persons with transfemoral amputation to systematic perturbations in knee joint alignment during a level walking task. Quantitative gait data were collected for three alignment conditions: bench alignment, 2 cm anterior knee translation (ANT), and 2 cm posterior knee translation (POST). In response to a destabilizing alignment perturbation (i.e., the ANT condition), participants significantly increased their early-stance hip extension moment, confirming that persons with transfemoral amputation rely on a hip extensor strategy to maintain knee joint stability. However, participants also decreased the rate at which they loaded their prosthesis, decreased their affected-side step length, increased their trunk flexion, and maintained their prosthesis in a more vertical posture at the time of opposite toe off. Collectively, these results suggest that persons with transfemoral amputation rely on a combination of strategies to coordinate stance-phase knee flexion. Further, comparatively few significant changes were observed in response to the POST condition, suggesting that a bias toward posterior alignment may have fewer implications in terms of stance-phase, knee joint control.

Early clinical results of a high-flexion, posterior-stabilized, mobile-bearing total knee arthroplasty: a US investigational device exemption trial.

PubMed

Scuderi, Giles R; Hedden, David R; Maltry, John A; Traina, Steven M; Sheinkop, Mitchell B; Hartzband, Mark A

2012-03-01

Between May 2001 and June 2004, 388 total knee arthroplasty cases were enrolled in a prospective, randomized, multicenter investigational device exemption trial. Patients received either the investigational high-flexion mobile-bearing knee or a fixed-bearing control. At 2 to 4 years of follow-up, results in 293 patients with degenerative joint disease were compared using Knee Society Assessment and Function scores, radiographic results, complications analysis, and survival estimates. The mobile-bearing and fixed-bearing groups demonstrated similar, significant improvement over preoperative assessments in Knee Scores, maximum flexion, and range of motion. One mobile-bearing arthroplasty required revision. Radiographic results were unremarkable, and implant-related complications were rare in both groups. At this early follow-up, the investigational high-flexion mobile-bearing knee and its fixed-bearing counterpart demonstrated comparable, effective performance. Copyright © 2012 Elsevier Inc. All rights reserved.

Dynamic restraint capacity of the hamstring muscles has important functional implications after anterior cruciate ligament injury and anterior cruciate ligament reconstruction.

PubMed

Bryant, Adam L; Creaby, Mark W; Newton, Robert U; Steele, Julie R

2008-12-01

The purpose of this study was to investigate the relation between knee functionality of anterior cruciate ligament deficient (ACLD) and anterior cruciate ligament reconstruction (ACLR) patients and hamstring antagonist torque generated during resisted knee extension. Cross-sectional. Laboratory based. Male ACLD subjects (n=10) (18-35 y) and 27 matched males who had undergone ACLR (14 patella tendon [PT] grafts and 13 combined semitendinosus/gracilis tendon grafts). Not applicable. Knee functionality was rated (0- to 100-point scale) by using the Cincinnati Knee Rating System. Using electromyography data from the semitendinosus (ST) and biceps femoris muscles, we created a mathematical model to estimate the opposing torque generated by the hamstrings during isokinetic knee extension in 10 degrees intervals from 80 degrees to 10 degrees knee flexion. Pearson product-moment correlations revealed that more functional ACLD subjects generated significantly (P<.05) higher hamstring antagonist torque throughout knee extension. In contrast, more functional PT subjects produced significantly lower hamstring antagonist torque at 80 degrees to 70 degrees knee flexion, whereas no significant associations were found between hamstring antagonist torque and knee functionality for the ST/gracilis tendon subjects. An increased hamstring antagonist torque generated by the more functional ACLD subjects, reflective of increased hamstring contractile force, is thought to represent a protective mechanism to compensate for mechanical instability. The restoration of anterior knee stability through ACLR negates the need for augmented hamstring antagonist torque.

Variability of Measurement of Patellofemoral Indices with Knee Flexion and Quadriceps Contraction: An MRI-Based Anatomical Study

PubMed Central

Laugharne, Edward; Bali, Navi; Purushothamdas, Sanjay; Almallah, Faris; Kundra, Rik

2016-01-01

Purpose The purpose of this study was to investigate the impact of varying knee flexion and quadriceps activity on patellofemoral indices measured on magnetic resonance imaging (MRI). Materials and Methods MRI of the knee was performed in 20 patients for indications other than patellar or patellofemoral pathology. Axial and sagittal sequences were performed in full extension of the knee with the quadriceps relaxed, full extension of the knee with the quadriceps contracted, 30° flexion of the knee with the quadriceps relaxed, and 30° flexion with the quadriceps contracted. Bisect offset, patella tilt angle, Insall-Salvati ratio and Caton-Deschamps index were measured. Results With the knee flexed to 30° and quadriceps relaxed, the mean values of patellar tilt angle, bisect offset, Insall-Salvati ratio and Caton-Deschamps index were all within normal limits. With the knee extended and quadriceps contracted, the mean patellar tilt angle (normal value, <15°) was 14.6° and the bisect offset (normal value, <65%) was 65%, while the Caton-Deschamps index was 1.34 (normal range, 0.6 to 1.3). With the knee extended and quadriceps relaxed, the mean Caton-Deschamps index was 1.31. Conclusions MRI scanning of the knee in extension with the quadriceps contracted leads to elevated patellofemoral indices. MRI taken with the knee in 30° of flexion allows more reliable assessment of the patellofemoral joint and minimises the confounding effect of quadriceps contraction. PMID:27894177

A Biomechanical Investigation of A Single-Limb Squat: Implications for Lower Extremity Rehabilitation Exercise

PubMed Central

Richards, Jim; Thewlis, Dominic; Selfe, James; Cunningham, Andrew; Hayes, Colin

2008-01-01

Context: Single-limb squats on a decline angle have been suggested as a rehabilitative intervention to target the knee extensors. Investigators, however, have presented very little empirical research in which they have documented the biomechanics of these exercises or have determined the optimum angle of decline used. Objective: To determine the involvement of the gastrocnemius and rectus femoris muscles and the external ankle and knee joint moments at 60° of knee flexion while performing a single-limb squat at different decline angles. Design: Participants acted as their own controls in a repeated-measures design. Patients or Other Participants: We recruited 10 participants who had no pain, injury, or neurologic disorder. Intervention(s): Participants performed single-limb squats at different decline angles. Main Outcome Measure(s): Angle-specific knee and ankle moments were calculated at 60° of knee flexion. Angle-specific electromyography (EMG) activity was calculated at 60° of knee flexion. Integrated EMG also was calculated to determine the level of muscle activity over the entire squat. Results: An increase was seen in the knee moments (P < .05) and integrated EMG in the rectus femoris (P < .001) as the decline angle increased. A decrease was seen in the ankle moments as the decline angle increased (P  =  .001), but EMG activity in the gastrocnemius increased between 16° and 24° (P  =  .018). Conclusions: As the decline angle increased, the knee extensor moment and EMG activity increased. As the decline angle increased, the ankle plantar-flexor moments decreased; however, an increase in the EMG activity was seen with the 24° decline angle compared with the 16° decline angle. This indicates that decline squats at an angle greater than 16° may not reduce passive calf tension, as was suggested previously, and may provide no mechanical advantage for the knee. PMID:18833310

Squat exercise to estimate knee megaprosthesis rehabilitation: a pilot study

PubMed Central

Lovecchio, Nicola; Zago, Matteo; Sciumè, Luciana; Lopresti, Maurizio; Sforza, Chiarella

2015-01-01

[Purpose] This study evaluated a specific rehabilitation protocol using a half squat after total knee reconstruction with distal femur megaprosthesis and tibial allograft-prosthesis composite. [Subject and Methods] Squat execution was recorded by a three-dimensional system before and after a specific rehabilitation program on a 28-year-old patient. Squat duration, body center of mass trajectory, and vertical range of motion were determined. Step width and joint angles and symmetry (hip flexion, extension, and rotation, knee flexion, and ankle dorsal and plantar flexion) were estimated. Knee and hip joint symmetry was computed using a bilateral cyclogram technique. [Results] After rehabilitation, the squat duration was longer (75%), step width was similar, and vertical displacement was higher. Hip flexion increased by over 20%, and ankle dorsiflexion diminished by 14%. The knee had the highest symmetry gain (4.1–3.4%). Angle-angle plot subtended areas decreased from 108° to 40°2 (hip) and from 204° to 85°2 (knee), showing improvement in movement symmetry. [Conclusion] We concluded that the squat is an effective multifactorial exercise to estimate rehabilitation outcomes after megaprosthesis, also considering that compressive and shear forces are minimal up to 60–70° of knee flexion. PMID:26311992

Wound closure in flexion versus extension following total knee arthroplasty: a systematic review.

PubMed

Smith, Toby O; Davies, Leigh; Hing, Caroline B

2010-06-01

Optimising knee range of motion following total knee arthroplasty (TKA) is important for patient satisfaction, functional outcome and early rehabilitation to promote accelerated discharge. Historically, wound closure following TKA has been performed in extension. It has been suggested that knee position during wound closure may influence range of motion and clinical outcomes following TKA. The purpose of this study was to determine whether TKA wounds should be closed in flexion or extension. An electronic search of MEDLINE, EMBASE, CINAHL and AMED databases was made in addition to a review of unpublished material. All included papers were critically appraised using a modified PEDro (Physiotherapy Evidence Database) critical appraisal tool. Three papers were eligible, assessing 237 TKAs. On analysis, patients with TKA wounds closed in flexion had greater flexion range of motion and required less domiciliary physiotherapy compared to those with wounds closed in full extension. The specific degree of knee flexion used when closing total knee replacement wounds may be an important variable to clinical outcome. However, the present evidence-base is limited in both size and methodological quality.

Effect of different postoperative limb positions on blood loss and range of motion in total knee arthroplasty: An updated meta-analysis of randomized controlled trials.

PubMed

Wu, Yuangang; Yang, Timin; Zeng, Yi; Si, Haibo; Li, Canfeng; Shen, Bin

2017-01-01

Postoperative limb positioning has been reported to be an efficient and simple way to reduce blood loss and improve range of motion following total knee arthroplasty (TKA). This meta-analysis was designed to compare the effectiveness of two different limb positions in primary TKA. A meta-analysis of the PubMed, CENTRAL, Web of Science, EMBASE and Google Search Engine electronic databases was performed. In this meta-analysis, two postoperative limb positions were considered: mild-flexion (flexion less than 60°) and high-flexion (flexion at 60° or more). The subgroups were analysed using RevMan 5.3. Nine RCTs were included with a total sample size of 913 patients. The mild- and high-flexion positions significantly reduced postoperative total blood loss (P = 0.04 and P = 0.01; respectively). Subgroup analysis indicated that knee flexion significantly reduced hidden blood loss when the knee was fixed in mild-flexion (P = 0.0004) and significantly reduced transfusion requirements (P = 0.03) and improved range of motion (ROM) (P < 0.00001) when the knee was fixed in high-flexion. However, the rates of wound-related infection, deep venous thrombosis (DVT) and pulmonary embolism (PE) did not significantly differ between the two flexion groups. This meta-analysis suggests that mild- and high-flexion positions have similar efficacy in reducing total blood loss. In addition, subgroup analysis indicates that the mild-flexion position is superior in decreasing hidden blood loss compared with high-flexion; the high-flexion position is superior to mild-flexion in reducing transfusion requirements and improving postoperative ROM. Thus, the use of the high-flexion position is a viable option to reduce blood loss in patients following primary TKA without increasing the risk of wound-related infection, DVT or PE. Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Reduced knee flexion is a possible cause of increased loading rates in individuals with patellofemoral pain.

PubMed

Silva, Danilo de Oliveira; Briani, Ronaldo Valdir; Pazzinatto, Marcella Ferraz; Ferrari, Deisi; Aragão, Fernando Amâncio; Azevedo, Fábio Mícolis de

2015-11-01

Stair ascent is an activity that exacerbates symptoms of individuals with patellofemoral pain. The discomfort associated with this activity usually results in gait modification such as reduced knee flexion in an attempt to reduce pain. Although such compensatory strategy is a logical approach to decrease pain, it also reduces the normal active shock absorption increasing loading rates and may lead to deleterious and degenerative changes of the knee joint. Thus, the aims of this study were (i) to investigate whether there is reduced knee flexion in adults with PFP compared to healthy controls; and (ii) to analyze loading rates in these subjects, during stair climbing. Twenty-nine individuals with patellofemoral pain and twenty-five control individuals (18-30 years) participated in this study. Each subject underwent three-dimensional kinematic and kinetic analyses during stair climbing on two separate days. Between-groups analyses of variance were performed to identify differences in peak knee flexion and loading rates. Intraclass correlation coefficient was performed to verify the reliability of the variables. On both days, the patellofemoral pain group demonstrated significantly reduced peak knee flexion and increased loading rates. In addition, the two variables obtained high to very high reliability. Reduced knee flexion during stair climbing as a strategy to avoid anterior knee pain does not seem to be healthy for lower limb mechanical distributions. Repeated loading at higher loading rates may be damaging to lower limb joints. Copyright © 2015 Elsevier Ltd. All rights reserved.

The effects of joint aspiration and intra-articular corticosteroid injection on flexion reflex excitability, quadriceps strength and pain in individuals with knee synovitis: a prospective observational study.

PubMed

Rice, David Andrew; McNair, Peter John; Lewis, Gwyn Nancy; Dalbeth, Nicola

2015-07-28

Substantial weakness of the quadriceps muscles is typically observed in patients with arthritis. This is partly due to ongoing neural inhibition that prevents the quadriceps from being fully activated. Evidence from animal studies suggests enhanced flexion reflex excitability may contribute to this weakness. This prospective observational study examined the effects of joint aspiration and intra-articular corticosteroid injection on flexion reflex excitability, quadriceps muscle strength and knee pain in individuals with knee synovitis. Sixteen patients with chronic arthritis and clinically active synovitis of the knee participated in this study. Knee pain flexion reflex threshold, and quadriceps peak torque were measured at baseline, immediately after knee joint aspiration alone and 5 ± 2 and 15 ± 2 days after knee joint aspiration and the injection of 40 mg of methylprednisolone acetate. Compared to baseline, knee pain was significantly reduced 5 (p = 0.001) and 15 days (p = 0.009) post intervention. Flexion reflex threshold increased immediately after joint aspiration (p = 0.009) and 5 (p = 0.01) and 15 days (p = 0.002) post intervention. Quadriceps peak torque increased immediately after joint aspiration (p = 0.004) and 5 (p = 0.001) and 15 days (p <0.001) post intervention. The findings from this study suggest that altered sensory output from an inflamed joint may increase flexion reflex excitability in humans, as has previously been shown in animals. Joint aspiration and corticosteroid injection may be a clinically useful intervention to reverse quadriceps muscle weakness in individuals with knee synovitis.

Lower limb flexion posture relates to energy absorption during drop landings with soldier-relevant body borne loads.

PubMed

Brown, T N; O'Donovan, M; Hasselquist, L; Corner, B; Schiffman, J M

2016-01-01

Fifteen military personnel performed 30-cm drop landings to quantify how body borne load (light, ∼6 kg, medium, ∼20 kg, and heavy, ∼40 kg) impacts lower limb kinematics and knee joint energy absorption during landing, and determine whether greater lower limb flexion increases energy absorption while landing with load. Participants decreased peak hip (P = 0.002), and knee flexion (P = 0.007) posture, but did not increase hip (P = 0.796), knee (P = 0.427) or ankle (P = 0.161) energy absorption, despite exhibiting greater peak hip (P = 0.003) and knee (P = 0.001) flexion, and ankle (P = 0.003) dorsiflexion angular impulse when landing with additional load. Yet, when landing with the light and medium loads, greater hip (R(2) = 0.500, P = 0.003 and R(2) = 0.314, P = 0.030) and knee (R(2) = 0.431, P = 0.008 and R(2) = 0.342, P = 0.022) flexion posture predicted larger knee joint energy absorption. Thus, military training that promotes hip and knee flexion, and subsequently greater energy absorption during landing, may potentially reduce risk of musculoskeletal injury and optimize soldier performance. Published by Elsevier Ltd.

Stiff Landings Are Associated With Increased ACL Injury Risk in Young Female Basketball and Floorball Players.

PubMed

Leppänen, Mari; Pasanen, Kati; Kujala, Urho M; Vasankari, Tommi; Kannus, Pekka; Äyrämö, Sami; Krosshaug, Tron; Bahr, Roald; Avela, Janne; Perttunen, Jarmo; Parkkari, Jari

2017-02-01

Few prospective studies have investigated the biomechanical risk factors of anterior cruciate ligament (ACL) injury. To investigate the relationship between biomechanical characteristics of vertical drop jump (VDJ) performance and the risk of ACL injury in young female basketball and floorball players. Cohort study; Level of evidence, 3. At baseline, a total of 171 female basketball and floorball players (age range, 12-21 years) participated in a VDJ test using 3-dimensional motion analysis. The following biomechanical variables were analyzed: (1) knee valgus angle at initial contact (IC), (2) peak knee abduction moment, (3) knee flexion angle at IC, (4) peak knee flexion angle, (5) peak vertical ground-reaction force (vGRF), and (6) medial knee displacement. All new ACL injuries, as well as match and training exposure, were then recorded for 1 to 3 years. Cox regression models were used to calculate hazard ratios (HRs) and 95% CIs. Fifteen new ACL injuries occurred during the study period (0.2 injuries/1000 player-hours). Of the 6 factors considered, lower peak knee flexion angle (HR for each 10° increase in knee flexion angle, 0.55; 95% CI, 0.34-0.88) and higher peak vGRF (HR for each 100-N increase in vGRF, 1.26; 95% CI, 1.09-1.45) were the only factors associated with increased risk of ACL injury. A receiver operating characteristic (ROC) curve analysis showed an area under the curve of 0.6 for peak knee flexion and 0.7 for vGRF, indicating a failed-to-fair combined sensitivity and specificity of the test. Stiff landings, with less knee flexion and greater vGRF, in a VDJ test were associated with increased risk of ACL injury among young female basketball and floorball players. However, although 2 factors (decreased peak knee flexion and increased vGRF) had significant associations with ACL injury risk, the ROC curve analyses revealed that these variables cannot be used for screening of athletes.

Alterations in neuromuscular function in girls with generalized joint hypermobility.

PubMed

Jensen, Bente Rona; Sandfeld, Jesper; Melcher, Pia Sandfeld; Johansen, Katrine Lyders; Hendriksen, Peter; Juul-Kristensen, Birgit

2016-10-03

Generalized Joint Hypermobility (GJH) is associated with increased risk of musculoskeletal joint pain. We investigated neuromuscular performance and muscle activation strategy. Girls with GJH and non-GJH (NGJH) performed isometric knee flexions (90°,110°,130°), and extensions (90°) at 20 % Maximum Voluntary Contraction, and explosive isometric knee flexions while sitting. EMG was recorded from knee flexor and extensor muscles. Early rate of torque development was 53 % faster for GJH. Reduced hamstring muscle activation in girls with GJH was found while knee extensor and calf muscle activation did not differ between groups. Flexion-extension and medial-lateral co-activation ratio during flexions were higher for girls with GJH than NGJH girls. Girls with GJH had higher capacity to rapidly generate force than NGJH girls which may reflect motor adaptation to compensate for hypermobility. Higher medial muscle activation indicated higher levels of medial knee joint compression in girls with GJH. Increased flexion-extension co-activation ratios in GJH were explained by decreased agonist drive to the hamstrings.

Anteroposterior stability of the knee during the stance phase of gait after anterior cruciate ligament deficiency.

PubMed

Chen, Chih-Hui; Li, Jing-Sheng; Hosseini, Ali; Gadikota, Hemanth R; Gill, Thomas J; Li, Guoan

2012-03-01

Quadriceps avoidance and higher flexion strategies have been assumed as effects of ACL deficiency on knee joint function during gait. However, the effect of ACL deficiency on anteroposterior stability of the knee during gait is not well defined. In this study, 10 patients with unilateral acute ACL ruptures and the contralateral side intact performed gait on a treadmill. Flexion angles and anteroposterior translation of the ACL injured and the intact controlateral knees were measured at every 10% of the stance phase of the gait (from heel strike to toe-off) using a combined MRI and dual fluoroscopic imaging system (DFIS). The data indicated that during the stance phase of the gait, the ACL-deficient knees showed higher flexion angles compared to the intact contralateral side, consistent with the assumption of a higher flexion gait strategy. However, the data also revealed that the ACL-deficient knees had higher anterior tibial translation compared to the intact contralateral side during the stance phase of the gait. The higher flexion gait strategy was not shown to correlate to a reduction of the anterior tibial translation in ACL deficient knees. These data may provide indications for conservative treatment or surgical reconstruction of the ACL injured knees in restoration of the knee kinematics during daily walking activities. Copyright © 2011 Elsevier B.V. All rights reserved.

Influence of prolonged intermittent high-intensity exercise on knee flexor strength in male and female soccer players.

PubMed

Mercer, Tom H; Gleeson, Nigel P; Wren, Karen

2003-06-01

This study investigated the effect of an acute, prolonged, intermittent, high-intensity single-leg pedalling exercise task (PIHIET) on the isokinetic leg strength of the knee flexors in six male and seven female collegiate soccer players. Following determination of single-leg VO(2peak), subjects completed a PIHIET designed to simulate the energetics of soccer match play (approximately 90 min in total; approximately 70% single-leg VO(2peak)). Pre-, mid- and post-PIHIET gravity-corrected indices of knee flexion peak torque (PT) and range of motion-relativised torque at 15% of knee flexion (RRT(15%); 0% = full knee extension) were assessed at a lever-arm angular velocity of 1.05 rad.s(-1)for intervention and control limbs using an isokinetic dynamometer. Repeated measures ANOVAs revealed significant condition (PIHIET, control) x time (pre-, mid-, post-PIHIET) interactions for knee flexion PT (F([2,22])=26.2; P<0.001) and RRT(15%) (F([2,22])=20.1; P<0.001). Flexion PT and RRT(15% )were observed to decrease, pre- to post-intervention, from 92.8 (28.7) N.m to 72.1 (28.0) N.m and from 63.8 (17.5) N.m to 47.9 (18.4) N.m respectively, for the intervention limb alone. These data corresponded to 22.3% and 24.9% mean reductions pre-post intervention in PT and RRT(15%). Exploratory post hoc analysis of the pattern of the relative deterioration (%) of PT and RRT(15%), for the intervention limb alone, revealed a three-way interaction [group (male, female) x parameter (PT, RRT(15%)) x assessment phase (pre- to mid-PIHIET, mid- to post-PIHIET)] (F(1,11)=5.2; P<0.05). This interaction characterised a greater deterioration of strength performance during the mid- to post-PIHIET assessment phase, at the extremes of range of motion (RRT(15%)) for the female group. The greater percentage of mid-post phase strength loss observed in women near the end-range extension may potentially be implicated in the higher incidence of knee injury reported in female soccer players.

The effect of spinal manipulation on imbalances in leg strength.

PubMed

Chilibeck, Philip D; Cornish, Stephen M; Schulte, Al; Jantz, Nathan; Magnus, Charlene R A; Schwanbeck, Shane; Juurlink, Bernhard H J

2011-09-01

We hypothesized that spinal manipulation (SM) would reduce strength imbalances between legs. Using an un-blinded randomized design, 28 males and 21 females (54 ± 19y) with at least a 15% difference in isometric strength between legs for hip flexion, extension, abduction, or knee flexion were randomized to treatment or placebo (mock spinal manipulation). Strength of the stronger and weaker legs for hip flexion, extension, abduction, and/or knee flexion was assessed before and after the intervention. SM reduced the relative strength difference between legs for knee flexion (mean ± SD 57 ± 53 to 5 ± 14%) and hip flexion (24 ± 12 to 11 ± 15%) compared to placebo (34 ± 29 to 24 ± 36%, and 20 ± 18 to 22 ± 26%, respectively) (p = 0.05). SM also improved strength in the weak leg for hip abduction (104 ± 43 to 116 ± 43 Nm) compared to placebo (84 ± 24 to 85 ± 31 Nm) (p = 0.03). This study suggests that spinal manipulation may reduce imbalances in strength between legs for knee and hip flexion.

Mobile-bearing TKA improved the anteroposterior joint stability in mid-flexion range comparing to fixed-bearing TKA.

PubMed

Minoda, Yukihide; Ikebuchi, Mitsuhiko; Mizokawa, Shigekazu; Ohta, Yoichi; Nakamura, Hiroaki

2016-11-01

Proper anteroposterior (AP) joint displacement is an important indicator of good clinical outcome following total knee arthroplasty (TKA). We hypothesized that a newly introduced mobile-bearing posterior stabilized (PS) prosthesis reduces the AP joint displacement. The aim of this study is to compare the AP joint displacement between a newly introduced mobile-bearing PS TKA in one knee and a conventional fixed-bearing PS TKA in other knee. 82 knees in 41 patients who had bilateral TKAs were investigated. All the patients received a conventional fixed-bearing PS prosthesis in one knee and a highly congruent mobile-bearing PS prosthesis in the other knee. AP joint displacement was measured using the KT-2000 arthrometer, at 30° and 75° in flexion, at average of 3.3 years after the operation. AP joint displacements at 30° in flexion were 6 ± 3 mm in the knees with the mobile-bearing PS prosthesis and 9 ± 4 mm in the knee with fixed-bearing PS prosthesis (p < 0.001). AP joint displacements at 75° in flexion were 4 ± 2 mm in the knees with the mobile-bearing PS prosthesis and 6 ± 3 mm in the knee with fixed-bearing PS prosthesis (p < 0.001). This study suggested that the design of the prosthesis can improve the AP joint stability in mid-flexion range.

Cartilage loss patterns within femorotibial contact regions during deep knee bend.

PubMed

Michael Johnson, J; Mahfouz, Mohamed R

2016-06-14

Osteoarthritis (OA) can alter knee kinematics and stresses. The relationship between cartilage loss in OA and kinematics is unclear, with existing work focusing on static wear and morphology. In this work, femorotibial cartilage maps were coupled with kinematics to investigate the relationship between kinematics and cartilage loss, allowing for more precise treatment and intervention. Cartilage thickness maps were created from healthy and OA subgroups (varus, valgus, and neutral) and mapped to a statistical bone atlas. Video fluoroscopy determined contact regions from 0° to 120° flexion. Varus and valgus subgroups displayed different wear patterns across the range of flexion, with varus knees showing more loss in early flexion and valgus in deeper flexion. For the femur, varus knees had more wear in the medial compartment than neutral or valgus and most wear at both 0° and 20° flexion. In the lateral femoral compartment, the valgus subgroup showed significantly more wear from 20° to 60° flexion as compared to other angles, though varus knees displayed highest magnitude of wear. For the tibia, most medial wear occurred at 0-40° flexion and most lateral occurred after 60° flexion. Knowing more about cartilage changes in OA knees provides insight as to expected wear or stresses on implanted components after arthroplasty. Combining cartilage loss patterns with kinematics allows for pre-surgical intervention and treatments tailored to the patient׳s alignment and kinematics. Reported wear patterns may also serve as a gauge for post-operative loading to be considered when placing implant components. Copyright © 2016. Published by Elsevier Ltd.

Predicting the Functional Roles of Knee Joint Muscles from Internal Joint Moments.

PubMed

Flaxman, Teresa E; Alkjær, Tine; Simonsen, Erik B; Krogsgaard, Michael R; Benoit, Daniel L

2017-03-01

Knee muscles are commonly labeled as flexors or extensors and aptly stabilize the knee against sagittal plane loads. However, how these muscles stabilize the knee against adduction-abduction and rotational loads remains unclear. Our study sought 1) to classify muscle roles as they relate to joint stability by quantifying the relationship between individual muscle activation patterns and internal net joint moments in all three loading planes and 2) to determine whether these roles change with increasing force levels. A standing isometric force matching protocol required subjects to modulate ground reaction forces to elicit various combinations and magnitudes of sagittal, frontal, and transverse internal joint moments. Surface EMG measured activities of 10 lower limb muscles. Partial least squares regressions determined which internal moment(s) were significantly related to the activation of individual muscles. Rectus femoris and tensor fasciae latae were classified as moment actuators for knee extension and hip flexion. Hamstrings were classified as moment actuators for hip extension and knee flexion. Gastrocnemius and hamstring muscles were classified as specific joint stabilizers for knee rotation. Vastii were classified as general joint stabilizers because activation was independent of moment generation. Muscle roles did not change with increasing effort levels. Our findings indicate muscle activation is not dependent on anatomical orientation but perhaps on its role in maintaining knee joint stability in the frontal and transverse loading planes. This is useful for delineating the roles of biarticular knee joint muscles and could have implications in robotics, musculoskeletal modeling, sports sciences, and rehabilitation.

Volitional Spine Stabilization During a Drop Vertical Jump From Different Landing Heights: Implications for Anterior Cruciate Ligament Injury.

PubMed

Haddas, Ram; Hooper, Troy; James, C Roger; Sizer, Phillip S

2016-12-01

Volitional preemptive abdominal contraction (VPAC) during dynamic activities may alter trunk motion, but the role of the core musculature in positioning the trunk during landing tasks is unclear. To determine whether volitional core-muscle activation incorporated during a drop vertical jump alters lower extremity kinematics and kinetics, as well as trunk and lower extremity muscle activity at different landing heights. Controlled laboratory study. Clinical biomechanics laboratory. Thirty-two young healthy adults, consisting of 17 men (age = 25.24 ± 2.88 years, height = 1.85 ± 0.06 m, mass = 89.68 ± 16.80 kg) and 15 women (age = 23.93 ± 1.33 years, height = 1.67 ± 0.08 m, mass = 89.68 ± 5.28 kg). Core-muscle activation using VPAC. We collected 3-dimensional ankle, knee, and hip motions, moments, and powers; ground reaction forces; and trunk and lower extremity muscle activity during 0.30- and 0.50-m drop vertical-jump landings. During landing from a 0.30-m height, VPAC performance increased external oblique and semitendinosis activity, knee flexion, and knee internal rotation and decreased knee-abduction moment and knee-energy absorption. During the 0.50-m landing, the VPAC increased external oblique and semitendinosis activity, knee flexion, and hip flexion and decreased ankle inversion and hip-energy absorption. The VPAC performance during landing may protect the anterior cruciate ligament during different landing phases from different heights, creating a protective advantage just before ground contact and after the impact phase. Incorporating VPAC during high injury-risk activities may enhance pelvic stability, improve lower extremity positioning and sensorimotor control, and reduce anterior cruciate ligament injury risk while protecting the lumbar spine.

An improved OpenSim gait model with multiple degrees of freedom knee joint and knee ligaments.

PubMed

Xu, Hang; Bloswick, Donald; Merryweather, Andrew

2015-08-01

Musculoskeletal models are widely used to investigate joint kinematics and predict muscle force during gait. However, the knee is usually simplified as a one degree of freedom joint and knee ligaments are neglected. The aim of this study was to develop an OpenSim gait model with enhanced knee structures. The knee joint in this study included three rotations and three translations. The three knee rotations and mediolateral translation were independent, with proximodistal and anteroposterior translations occurring as a function of knee flexion/extension. Ten elastic elements described the geometrical and mechanical properties of the anterior and posterior cruciate ligaments (ACL and PCL), and the medial and lateral collateral ligaments (MCL and LCL). The three independent knee rotations were evaluated using OpenSim to observe ligament function. The results showed that the anterior and posterior bundles of ACL and PCL (aACL, pACL and aPCL, pPCL) intersected during knee flexion. The aACL and pACL mainly provided force during knee flexion and adduction, respectively. The aPCL was slack throughout the range of three knee rotations; however, the pPCL was utilised for knee abduction and internal rotation. The LCL was employed for knee adduction and rotation, but was slack beyond 20° of knee flexion. The MCL bundles were mainly used during knee adduction and external rotation. All these results suggest that the functions of knee ligaments in this model approximated the behaviour of the physical knee and the enhanced knee structures can improve the ability to investigate knee joint biomechanics during various gait activities.

The effects of 2 landing techniques on knee kinematics, kinetics, and performance during stop-jump and side-cutting tasks.

PubMed

Dai, Boyi; Garrett, William E; Gross, Michael T; Padua, Darin A; Queen, Robin M; Yu, Bing

2015-02-01

Anterior cruciate ligament injuries (ACL) commonly occur during jump landing and cutting tasks. Attempts to land softly and land with greater knee flexion are associated with decreased ACL loading. However, their effects on performance are unclear. Attempts to land softly will decrease peak posterior ground-reaction force (PPGRF) and knee extension moment at PPGRF compared with a natural landing during stop-jump and side-cutting tasks. Attempts to land with greater knee flexion at initial ground contact will increase knee flexion at PPGRF compared with a natural landing during both tasks. In addition, both landing techniques will increase stance time and lower extremity mechanical work as well as decrease jump height and movement speed compared with a natural landing during both tasks. Controlled laboratory study. A total of 18 male and 18 female recreational athletes participated in the study. Three-dimensional kinematic and kinetic data were collected during stop-jump and side-cutting tasks under 3 conditions: natural landing, soft landing, and landing with greater knee flexion at initial ground contact. Attempts to land softly decreased PPGRF and knee extension moment at PPGRF compared with a natural landing during stop-jump tasks. Attempts to land softly decreased PPGRF compared with a natural landing during side-cutting tasks. Attempts to land with greater knee flexion at initial ground contact increased knee flexion angle at PPGRF compared with a natural landing during both stop-jump and side-cutting tasks. Attempts to land softly and land with greater knee flexion at initial ground contact increased stance time and lower extremity mechanical work, as well as decreased jump height and movement speed during both stop-jump and side-cutting tasks. Although landing softly and landing with greater knee flexion at initial ground contact may reduce ACL loading during stop-jump and side-cutting tasks, the performance of these tasks decreased, as indicated by increased stance time and mechanical work as well as decreased jump height and movement speed. Training effects tested in laboratory environments with the focus on reducing ACL loading may be reduced in actual competition environments when the focus is on athlete performance. The effects of training programs for ACL injury prevention on lower extremity biomechanics in athletic tasks may need to be evaluated in laboratories as well as in actual competitions. © 2014 The Author(s).

Effect of Rhythmic Auditory Stimulation on Hemiplegic Gait Patterns.

PubMed

Shin, Yoon-Kyum; Chong, Hyun Ju; Kim, Soo Ji; Cho, Sung-Rae

2015-11-01

The purpose of our study was to investigate the effect of gait training with rhythmic auditory stimulation (RAS) on both kinematic and temporospatial gait patterns in patients with hemiplegia. Eighteen hemiplegic patients diagnosed with either cerebral palsy or stroke participated in this study. All participants underwent the 4-week gait training with RAS. The treatment was performed for 30 minutes per each session, three sessions per week. RAS was provided with rhythmic beats using a chord progression on a keyboard. Kinematic and temporospatial data were collected and analyzed using a three-dimensional motion analysis system. Gait training with RAS significantly improved both proximal and distal joint kinematic patterns in hip adduction, knee flexion, and ankle plantar flexion, enhancing the gait deviation index (GDI) as well as ameliorating temporal asymmetry of the stance and swing phases in patients with hemiplegia. Stroke patients with previous walking experience demonstrated significant kinematic improvement in knee flexion in mid-swing and ankle dorsiflexion in terminal stance. Among stroke patients, subacute patients showed a significantly increased GDI score compared with chronic patients. In addition, household ambulators showed a significant effect on reducing anterior tilt of the pelvis with an enhanced GDI score, while community ambulators significantly increased knee flexion in mid-swing phase and ankle dorsiflexion in terminal stance phase. Gait training with RAS has beneficial effects on both kinematic and temporospatial patterns in patients with hemiplegia, providing not only clinical implications of locomotor rehabilitation with goal-oriented external feedback using RAS but also differential effects according to ambulatory function.

Effects of hamstring stretching on passive muscle stiffness vary between hip flexion and knee extension maneuvers.

PubMed

Miyamoto, N; Hirata, K; Kanehisa, H

2017-01-01

The purpose of this study was to examine whether the effects of hamstring stretching on the passive stiffness of each of the long head of the biceps femoris (BFl), semitendinosus (ST), and semimembranosus (SM) vary between passive knee extension and hip flexion stretching maneuvers. In 12 male subjects, before and after five sets of 90 s static stretching, passive lengthening measurements where knee or hip joint was passively rotated to the maximal range of motion (ROM) were performed. During the passive lengthening, shear modulus of each muscle was measured by ultrasound shear wave elastography. Both stretching maneuvers significantly increased maximal ROM and decreased passive torque at a given joint angle. Passive knee extension stretching maneuver significantly reduced shear modulus at a given knee joint angle in all of BFl, ST, and SM. In contrast, the stretching effect by passive hip flexion maneuver was significant only in ST and SM. The present findings indicate that the effects of hamstring stretching on individual passive muscles' stiffness vary between passive knee extension and hip flexion stretching maneuvers. In terms of reducing the muscle stiffness of BFl, stretching of the hamstring should be performed by passive knee extension rather than hip flexion. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Laxity Profiles in the Native and Replaced Knee-Application to Robotic-Assisted Gap-Balancing Total Knee Arthroplasty.

PubMed

Shalhoub, Sami; Moschetti, Wayne E; Dabuzhsky, Leonid; Jevsevar, David S; Keggi, John M; Plaskos, Christopher

2018-05-14

The traditional goal of the gap-balancing method in total knee arthroplasty is to create equal and symmetric knee laxity throughout the arc of flexion. The purpose of this study was to (1) quantify the laxity in the native and the replaced knee throughout the range of flexion in gap-balancing total knee arthroplasty (TKA) and (2) quantify the precision in achieving a targeted gap profile throughout flexion using a robotic-assisted technique with active ligament tensioning. Robotic-assisted, gap-balancing TKA was performed in 14 cadaver specimens. The proximal tibia was resected, and the native tibiofemoral gaps were measured using a robotic tensioner that dynamically tensioned the soft-tissue envelope throughout the arc of flexion. The femoral implant was then aligned to balance the gaps at 0° and 90° of flexion. The postoperative gaps were then measured during final trialing with the robotic tensioner and compared with the planned gaps. The native gaps increased by 3.4 ± 1.7 mm medially and 3.7 ± 2.1 mm laterally from full extension to 20° of flexion (P < .001) and then remained consistent through the remaining arc of flexion. Gap balancing after TKA produced equal gaps at 0° and 90° of flexion, but the gap laxity in midflexion was 2-4 mm greater than at 0° and 90° (P < .001). The root mean square error between the planned gaps and actual measured postoperative gaps was 1.6 mm medially and 1.7 mm laterally throughout the range of motion. Aiming for equal gaps at 0° and 90° of flexion produced equal gaps in extension and flexion with larger gaps in midflexion. Consistent soft-tissue balance to a planned gap profile could be achieved by using controlled ligament tensioning in robotic-assisted TKA. Copyright © 2018 Elsevier Inc. All rights reserved.

Influence of post-cam design of posterior stabilized knee prosthesis on tibiofemoral motion during high knee flexion.

PubMed

Lin, Kun-Jhih; Huang, Chang-Hung; Liu, Yu-Liang; Chen, Wen-Chuan; Chang, Tsung-Wei; Yang, Chan-Tsung; Lai, Yu-Shu; Cheng, Cheng-Kung

2011-10-01

The post-cam design of contemporary posterior stabilized knee prosthesis can be categorized into flat-on-flat or curve-on-curve contact surfaces. The curve-on-curve design has been demonstrated its advantage of reducing stress concentration when the knee sustained an anteroposterior force with tibial rotation. How the post-cam design affects knee kinematics is still unknown, particularly, to compare the difference between the two design features. Analyzing knee kinematics of posterior stabilized knee prosthesis with various post-cam designs should provide certain instructions to the modification of prosthesis design. A dynamic knee model was utilized to investigate tibiofemoral motion of various post-cam designs during high knee flexion. Two posterior stabilized knee models were constructed with flat-on-flat and curve-on-curve contact surfaces of post-cam. Dynamic data of axial tibial rotation and femoral translation were measured from full-extension to 135°. Internal tibial rotation increased with knee flexion in both designs. Before post-cam engagement, the magnitude of internal tibial rotation was close in the two designs. However, tibial rotation angle decreased beyond femoral cam engaged with tibial post. The rate of reduction of tibial rotation was relatively lower in the curve-on-curve design. From post-cam engagement to extreme flexion, the curve-on-curve design had greater internal tibial rotation. Motion constraint was generated by medial impingement of femoral cam on tibial post. It would interfere with the axial motion of the femur relative to the tibia, resulting in decrease of internal tibial rotation. Elimination of rotational constraint should be necessary for achieving better tibial rotation during high knee flexion. Copyright © 2011 Elsevier Ltd. All rights reserved.

The Influence of Knee Flexion Angle for Graft Fixation on Rotational Knee Stability During Anterior Cruciate Ligament Reconstruction: A Biomechanical Study.

PubMed

Debandi, Aníbal; Maeyama, Akira; Hoshino, Yuichi; Asai, Shigehiro; Goto, Bunsei; Smolinski, Patrick; Fu, Freddie H

2016-11-01

To evaluate the effect of knee flexion angle for hamstring graft fixation, full extension (FE), or 30°, on acceleration of the knee motion during pivot-shift testing after either anatomic or nonanatomic anterior cruciate ligament (ACL) reconstruction using triaxial accelerometry. Two types of ACL reconstructions (anatomic and nonanatomic) using 2 different angles of knee flexion during graft fixation (FE and 30°) were performed on 12 fresh-frozen human knees making 4 groups: anatomic-FE, anatomic-30°, nonanatomic-FE, and nonanatomic-30°. Manual pivot-shift testing was performed at ACL-intact, ACL-deficient, and ACL-reconstructed conditions. Three-dimensional acceleration of knee motion was recorded using a triaxial accelerometer. The anatomic-30° group showed the smallest overall magnitude of acceleration among the ACL-reconstructed groups (P = .0039). There were no significant differences among the anatomic-FE group, the nonanatomic-FE group, and the nonantomic-30° group (anatomic-FE vs nonanatomic-FE, P = .1093; anatomic-FE vs nonanatomic-30°, P = .8728; and nonanatomic-FE vs nonanatomic-30°, P = .1093). After ACL transection, acceleration was reduced by ACL reconstruction with the exception of the nonanatomic-FE group that did not show a significant difference when compared with the ACL-deficient (P = .4537). The anatomic ACL reconstruction with the graft fixed at 30° of knee flexion better restored rotational knee stability compared with FE. An ACL graft fixed with the knee at FE in anatomic position did not show a significant difference compared with the nonanatomic ACL reconstructions. Knee flexion angle at the time of graft fixation for ACL reconstruction can be considered to maximize the rotational knee stability. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

The comparison of transfemoral amputees using mechanical and microprocessor- controlled prosthetic knee under different walking speeds: A randomized cross-over trial.

PubMed

Cao, Wujing; Yu, Hongliu; Zhao, Weiliang; Meng, Qiaoling; Chen, Wenming

2018-04-20

The microprocessor-controlled prosthetic knees have been introduced to transfemoral amputees due to advances in biomedical engineering. A body of scientific literature has shown that the microprocessor-controlled prosthetic knees improve the gait and functional abilities of persons with transfemoral amputation. The aim of this study was to propose a new microprocessor-controlled prosthetic knee (MPK) and compare it with non-microprocessor-controlled prosthetic knees (NMPKs) under different walking speeds. The microprocessor-controlled prosthetic knee (i-KNEE) with hydraulic damper was developed. The comfortable self-selected walking speeds of 12 subjects with i-KNEE and NMPK were obtained. The maximum swing flexion knee angle and gait symmetry were compared in i-KNEE and NMPK condition. The comfortable self-selected walking speeds of some subjects were higher with i-KNEE while some were not. There was no significant difference in comfortable self-selected walking speed between the i-KNEE and the NMPK condition (P= 0.138). The peak prosthetic knee flexion during swing in the i-KNEE condition was between sixty and seventy degree under any walking speed. In the NMPK condition, the maximum swing flexion knee angle changed significantly. And it increased with walking speed. There is no significant difference in knee kinematic symmetry when the subjects wear the i-KNEE or NMPK. The results of this study indicated that the new microprocessor-controlled prosthetic knee was suitable for transfemoral amputees. The maximum swing flexion knee angle under different walking speeds showed different properties in the NMPK and i-KNEE condition. The i-KNEE was more adaptive to speed changes. There was little difference of comfortable self-selected walking speed between i-KNEE and NMPK condition.

Human torque velocity adaptations to sprint, endurance, or combined modes of training

NASA Technical Reports Server (NTRS)

Shealy, M. J.; Callister, R.; Dudley, G. A.; Fleck, S. J.

1992-01-01

We had groups of athletes perform sprint and endurance run training independently or concurrently for 8 weeks to examine the voluntary in vivo mechanical responses to each type of training. Pre- and posttraining angle-specific peak torque during knee extension and flexion were determined at 0, 0.84, 1.65, 2.51, 3.35, 4.19, and 5.03 radian.sec-1 and normalized for lean body mass. Knee extension torque in the sprint-trained group increased across all test velocities, the endurance-trained group increased at 2.51, 3.34, 4.19, and 5.03 radian.sec-1, and the group performing the combined training showed no change at any velocity. Knee flexion torque of the sprint and combined groups decreased at 0.84, 1.65, and 2.51 radian.sec-1. Knee flexion torque in the sprint-trained group also decreased at 0 radian.sec-1 and in the combined group at 3.34 radian.sec-1. Knee flexion torque in the endurance-trained group showed no change at any velocity of contraction. Mean knee flexion:extension ratios across the test velocities significantly decreased in the sprint-trained group. Knee extension endurance during 30 seconds of maximal contractions significantly increased in all groups. Only the sprint-trained group showed a significant increase in endurance of the knee flexors. These data suggest that changes in the voluntary in vivo mechanical characteristics of knee extensor and flexor skeletal muscles are specific to the type of run training performed.

Gender differences in tibio-femoral kinematics and quadriceps muscle force during weight-bearing knee flexion in vitro.

PubMed

Wünschel, Markus; Wülker, Nikolaus; Müller, Otto

2013-11-01

Females have a higher risk in terms of anterior cruciate ligament injuries during sports than males. Reasons for this fact may be different anatomy and muscle recruitment patterns leading to less protection for the cruciate- and collateral-ligaments. This in vitro study aims to evaluate gender differences in knee joint kinematics and muscle force during weight-bearing knee flexions. Thirty-four human knee specimens (17 females/17 males) were mounted on a dynamic knee simulator. Weight-bearing single-leg knee flexions were performed with different amounts of simulated body weight (BW). Gender-specific kinematics was measured with an ultrasonic motion capture system and different loading conditions were examined. Knee joint kinematics did not show significant differences regarding anteroposterior and medial-lateral movement as well as tibial varus-valgus and internal-external rotation. This applied to all simulated amounts of BW. Simulating 100 N BW in contrast to AF50 led to a significant higher quadriceps overall force in female knees from 45° to 85° of flexion in contrast to BW 50 N. In these female specimens, the quadriceps overall force was about 20 % higher than in male knees being constant in higher flexion angles. It is indicated by our results that in a squatting movement females compared with males produce higher muscle forces, suggesting an increased demand for muscular stabilization, whereas tibio-femoral kinematics was similar for both genders.

Medial Patellofemoral Ligament Reconstruction: Impact of Knee Flexion Angle During Graft Fixation on Dynamic Patellofemoral Contact Pressure-A Biomechanical Study.

PubMed

Lorbach, Olaf; Zumbansen, Nikolaus; Kieb, Matthias; Efe, Turgay; Pizanis, Antonius; Kohn, Dieter; Haupert, Alexander

2018-04-01

Objective evaluation of the optimal graft tension angle to fully restore patellofemoral contact pressure in reconstruction of the medial patellofemoral ligament (MPFL) in comparison to the native knee. Twelve cadaveric knee specimens were fixed in a custom-made fixation device. A sensitive pressure film (Tekscan) was fixed in the patellofemoral joint, and patellofemoral contact pressure was assessed during a dynamic flexion movement from 0° to 90°. The MPFL was cut and measurements were repeated. Reconstruction of the MPFL was performed with the gracilis tendon subsequently fixed in the femur at 15°, 30°, 45°, 60°, 75°, and 90° of knee flexion under controlled tension (2 N). The sequence of the flexion angles was alternated. Pressure measurements were repeated after every fixation of the graft. No significant differences were seen in the overall patellofemoral contact pressure compared to the native knee (P > .05). However, medial patellofemoral pressure showed a significant increased patellofemoral contact pressure after MPFL reconstruction at a knee flexion angle during graft fixation of 15° (P = .027), 45° (P = .050, P = .044), and 75° (P = .039). Moreover, proximal/distal patellofemoral contact pressure revealed a significantly reduced contact pressure at 15° (P = .003), 30° (P = .009), 45° (P = .025), 75° (P = .021), and 90° (P = .022) of flexion distal after MPFL reconstruction compared with the intact knee. Lateral patellofemoral contact pressure was significantly reduced in all performed reconstructions (P < .05). The flexion angle during graft fixation for MPFL reconstruction did not have a significant impact on the overall patellofemoral contact pressure. However, selective medial, proximal, distal, and lateral patellofemoral contact pressure was significantly altered for all reconstructions. Fixation of the MPFL graft at 60° of flexion was able to most closely restore patellofemoral contact pressure compared with the intact knee. Based on the findings of the present study, fixation of the graft in anatomic reconstruction of the MPFL should be considered in 60° of flexion under low tension (2 N) to most closely restore patellofemoral contact pressure compared with the native knee. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

The relation between knee flexion angle and anterior cruciate ligament femoral tunnel characteristics: a cadaveric study comparing a standard and a far anteromedial portal.

PubMed

Alavekios, Damon; Peterson, Alexander; Patton, John; McGarry, Michelle H; Lee, Thay Q

2014-11-01

The purpose of this study was to compare the anterior cruciate ligament (ACL) femoral tunnel characteristics between 2 common arthroscopic portals used for ACL reconstruction, a standard anteromedial portal and a far anteromedial portal. Seven cadaveric knees were used. A 1.25-mm Kirschner wire was drilled through the center of the ACL femoral footprint and through the distal femur from the standard anteromedial and far anteromedial portals at knee flexion angles of 100°, 120°, and 140°. No formal tunnels were drilled. Each tunnel exit point was marked with a colored pin. After all tunnels were created, the specimens were digitized with a MicroScribe device (Revware, Raleigh, NC) to measure the tunnel length; distance to the posterior femoral cortical wall (posterior cortical margin); and tunnel orientation in the sagittal, coronal, and axial planes. The standard anteromedial portal resulted in a longer tunnel length, a less horizontal tunnel in the coronal plane, and a greater posterior cortical margin compared with the far anteromedial portal at all knee flexion angles. For both portal locations, the tunnel length and posterior cortical margin increased, and the tunnel position became more horizontal in the coronal plane, more anterior in the sagittal plane, and less horizontal in the transverse plane as knee flexion increased. Portal position affects femoral tunnel characteristics, with results favoring the more laterally positioned standard anteromedial portal at all flexion angles. Increasing the knee flexion angle leads to a longer femoral tunnel length and posterior femoral cortical margin with either portal position. Understanding how portal positioning and knee flexion angle affect femoral tunnel orientation and characteristics may lead to improved surgical outcomes after ACL reconstruction. Published by Elsevier Inc.

MRI-based analysis of patellofemoral cartilage contact, thickness, and alignment in extension, and during moderate and deep flexion.

PubMed

Freedman, Benjamin R; Sheehan, Frances T; Lerner, Amy L

2015-10-01

Several factors are believed to contribute to patellofemoral joint function throughout knee flexion including patellofemoral (PF) kinematics, contact, and bone morphology. However, data evaluating the PF joint in this highly flexed state have been limited. Therefore, the purpose of this study was to evaluate patellofemoral contact and alignment in low (0°), moderate (60°), and deep (140°) knee flexion, and then correlate these parameters to each other, as well as to femoral morphology. Sagittal magnetic resonance images were acquired on 14 healthy female adult knees (RSRB approved) using a 1.5 T scanner with the knee in full extension, mid-flexion, and deep flexion. The patellofemoral cartilage contact area, lateral contact displacement (LCD), cartilage thickness, and lateral patellar displacement (LPD) throughout flexion were defined. Intra- and inter-rater repeatability measures were determined. Correlations between patellofemoral contact parameters, alignment, and sulcus morphology were calculated. Measurement repeatability ICCs ranged from 0.94 to 0.99. Patellofemoral cartilage contact area and thickness, LCD, and LPD were statistically different throughout all levels of flexion (p<0.001). The cartilage contact area was correlated to LPD, cartilage thickness, sulcus angle, and epicondylar width (r=0.47-0.72, p<0.05). This study provides a comprehensive analysis of the patellofemoral joint throughout its range of motion. This study agrees with past studies that investigated patellofemoral measures at a single flexion angle, and provides new insights into the relationship between patellofemoral contact and alignment at multiple flexion angles. The study provides a detailed analysis of the patellofemoral joint in vivo, and demonstrates the feasibility of using standard clinical magnetic resonance imaging scanners to image the knee joint in deep flexion. Copyright © 2015 Elsevier B.V. All rights reserved.

Predictors of outcome after manipulation under anaesthesia in patients with a stiff total knee arthroplasty.

PubMed

Vanlommel, L; Luyckx, T; Vercruysse, G; Bellemans, J; Vandenneucker, H

2017-11-01

Flexion in a stiff total knee arthroplasty (TKA) can be improved by manipulation under anaesthesia (MUA). Although this intervention usually results in an improvement in range of motion, the expected result is not always achieved. The purpose of this study is to determine which factors affect range of motion after manipulation in patients with a stiff total knee. After exclusion (n = 22), the data of 158 patients (138 knees) with a stiff knee after TKA who received a manipulation under anaesthesia between 2004 and 2014 were retrospectively analysed. Pre-, peri- and post-operative variables were identified and examined for their influence on flexion after the manipulation using Kruskal-Wallis and Mann-Whitney U tests and Spearman correlations. After MUA, a mean improvement in flexion of 30.3° was observed at the final follow-up. Preoperative TKA flexion, design of TKA and interval between TKA procedure and MUA were positive associated with an increase in flexion after MUA. MUA performed 12 weeks or more after TKA procedure deteriorated the outcome. Three factors, pre-TKA flexion type of prosthesis and interval between TKA procedure and manipulation under anaesthesia, were found to have impact on flexion after TKA and MUA were identified. Results are expected to be inferior in patients with low flexion before TKA procedure or with a long interval (>12 weeks) between the TKA procedure and the manipulation under anaesthesia. IV.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Niitsu, Mamoru; Ikeda, Kotaroh; Fukubayashi, Tohru

Our goal was to assess the effect of joint position of semiflexed and extended knees in MR delineation of the anterior cruciate ligament (ACL). With a mobile knee brace and a flexible surface coil, the knee joint was either fully extended or bent to a semiflexed position (average 45{degrees} of flexion) within the magnet bore. Sets of oblique sagittal MR images were obtained for both extended and flexed knee positions. Thirty-two knees with intact ACLs and 43 knees with arthroscopically proven ACL tears were evaluated. Two observers compared paired MR images of both extended and flexed positions and rated themmore » by a relative three point scale. Anatomic correlation in MR images was obtained by a cadaveric knee with incremental flexion. The MR images of flexed knees were more useful than of extended knees in 53% of the case reviews of femoral attachments and 36% of reviews of midportions of normal ACLs. Compared with knee extensions, the MR images for knee flexion provided better clarity in 48% of reviews of disrupted sites and 52% of residual bundles of torn ACLs. Normal ACL appeared taut in the knee extension and lax in semiflexion. Compared with MR images of knees in extension, MR images of knees in flexion more clearly delineate the femoral side of the ligament with wider space under the intercondylar roof and with decreased volume-averaging artifacts, providing superior visualization of normal and torn ACLs. 13 refs., 7 figs., 1 tab.« less

Assessment of the midflexion rotational laxity in posterior-stabilized total knee arthroplasty.

PubMed

Hino, Kazunori; Kutsuna, Tatsuhiko; Oonishi, Yoshio; Watamori, Kunihiko; Kiyomatsu, Hiroshi; Iseki, Yasutake; Watanabe, Seiji; Ishimaru, Yasumitsu; Miura, Hiromasa

2017-11-01

To evaluate changes in midflexion rotational laxity before and after posterior-stabilized (PS)-total knee arthroplasty (TKA). Twenty-nine knees that underwent PS-TKA were evaluated. Manual mild passive rotational stress was applied to the knees, and the internal-external rotational angle was measured automatically by a navigation system at 30°, 45°, 60°, and 90° of knee flexion. The post-operative internal rotational laxity was statistically significantly increased compared to the preoperative level at 30°, 45°, 60°, and 90° of flexion. The post-operative external rotational laxity was statistically significantly decreased compared to the preoperative level at 45° and 60° of flexion. The post-operative internal-external rotational laxity was statistically significantly increased compared to the preoperative level only at 30° of flexion. The preoperative and post-operative rotational laxity showed a significant correlation at 30°, 45°, 60°, and 90° of flexion. Internal-external rotational laxity increases at the initial flexion range due to resection of both the anterior or posterior cruciate ligaments and retention of the collateral ligaments in PS-TKA. Preoperative and post-operative rotational laxity indicated a significant correlation at the midflexion range. This study showed that a large preoperative rotational laxity increased the risk of a large post-operative laxity, especially at the initial flexion range in PS-TKA. III.

Effect of a pelvic wedge and belt on the medial and lateral hamstring muscles during knee flexion.

PubMed

Yoo, Won-Gyu

2017-01-01

[Purpose] This study developed a pelvic wedge and belt and investigated their effects on the selective activation of medial and lateral hamstring muscles during knee flexion. [Subjects and Methods] Nine adults were enrolled. The participants performed exercises without and with the pelvic wedge and belt, and the electromyographic activities of the medial and lateral hamstring muscles were recorded. [Results] The activity of the medial hamstring was increased significantly when using the pelvic wedge and belt, while the activity of the lateral hamstring did not differ significantly. [Conclusion] The pelvic wedge and belt provide a self-locked position during knee flexion in the prone position. Prone knee flexion in this position is an effective self-exercise for balanced strengthening of the medial hamstring.

Effect of a pelvic wedge and belt on the medial and lateral hamstring muscles during knee flexion

PubMed Central

Yoo, Won-gyu

2017-01-01

[Purpose] This study developed a pelvic wedge and belt and investigated their effects on the selective activation of medial and lateral hamstring muscles during knee flexion. [Subjects and Methods] Nine adults were enrolled. The participants performed exercises without and with the pelvic wedge and belt, and the electromyographic activities of the medial and lateral hamstring muscles were recorded. [Results] The activity of the medial hamstring was increased significantly when using the pelvic wedge and belt, while the activity of the lateral hamstring did not differ significantly. [Conclusion] The pelvic wedge and belt provide a self-locked position during knee flexion in the prone position. Prone knee flexion in this position is an effective self-exercise for balanced strengthening of the medial hamstring. PMID:28210048

Influence of Medial Collateral Ligament Release for Internal Rotation of Tibia in Posterior-Stabilized Total Knee Arthroplasty: A Cadaveric Study.

PubMed

Wada, Keizo; Hamada, Daisuke; Tamaki, Shunsuke; Higashino, Kosaku; Fukui, Yoshihiro; Sairyo, Koichi

2017-01-01

Previous studies suggested that changes in kinematics in total knee arthroplasty (TKA) affected satisfaction level. The aim of this cadaveric study was to evaluate the effect of medial collateral ligament (MCL) release by multiple needle puncture on knee rotational kinematics in posterior-stabilized TKA. Six fresh, frozen cadaveric knees were included in this study. All TKA procedures were performed with an image-free navigation system using a 10-mm polyethylene insert. Tibial internal rotation was assessed to evaluate intraoperative knee kinematics. Multiple needle puncturing was performed 5, 10, and 15 times for the hard portion of the MCL at 90° knee flexion. Kinematic analysis was performed after every 5 punctures. After performing 15 punctures, a 14-mm polyethylene insert was inserted, and kinematic analysis was performed. The tibial internal rotation angle at maximum knee flexion without multiple needle puncturing was significantly larger (9.42°) than that after 15 punctures (3°). Negative correlation (Pearson r = -0.715, P < .001) between tibial internal rotation angle at maximum knee flexion and frequency of puncture was observed. The tibial internal rotation angle with a 14-mm insert was significantly larger (7.25°) compared with the angle after 15 punctures. Tibial internal rotation during knee flexion was reduced by extensive MCL release using multiple needle puncturing and was recovered by increasing of medial tightness. From the point of view of knee kinematics, medial tightness should be allowed to maintain the internal rotation angle of the tibia during knee flexion which might lead to patient satisfaction. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of Single-Bundle and Double-Bundle ACL Reconstruction on Tibiofemoral Compressive Stresses and Joint Kinematics During Simulated Squatting

PubMed Central

Mulcahey, Mary K.; Monchik, Keith O.; Yongpravat, Charlie; Badger, Gary J.; Fadale, Paul D.; Hulstyn, Michael J.; Fleming, Braden C.

2011-01-01

The purpose of this study was to compare tibiofemoral (TF) kinematics and TF compressive stresses between single bundle- (SB-) and double bundle-ACL reconstruction (DB-ACLR) during simulated squatting. Twelve matched pairs of fresh frozen cadaver knees were utilized. A simulated squat through 100° of knee flexion was performed in the ACL-intact joint. The ACL was transected and SB- and DB-ACLR procedures were performed in one knee of each pair. The squat was repeated. Knee kinematics were measured using a motion tracking system and the TF compressive forces were measured using thin film pressure sensors. The posterior shifts of the tibia for SB- and DB-ACLR knees were significantly greater than the ACL-intact condition for knee flexion angles 0° to 40° (p<.05). However, there was no difference between the SB- and DB-ACLR knees at any flexion angle (0° to 100°; p=.37). SB- and DB-ACLR knees had greater IE rotation than intact knees from 90° through 50° of flexion (p<.05), but not between 40° and full extension. There was no difference between SB- and DB-ACLR knees (p=.68). The TF compressive stresses of the DB-ACLR were significantly lower than intact for all angles except 10° (p=.06), whereas SB-ACLR knees did not differ from intact at flexion angles between 30° and 50° (p>.32). There were no significant differences between the two reconstruction conditions (p=.74). This study showed that there was no difference in the TF kinematics or compressive stresses between SB- and DB-ACLR, and only minor differences when compared to the intact state. PMID:21696962

The Mediolateral Excursion of the Meniscal Bearing during Flexion and Extension of the Knee after Medial Mobile-Bearing Unicompartmental Knee Arthroplasty.

PubMed

Lee, Seung-Yup; Bae, Ji-Hoon; Suh, Dong-Won; Kim, Han-Ju; Lim, Hong-Chul

2017-02-01

This mediolateral excursion of the bearing during knee motion is supposed to be caused by external rotation of the tibia during knee extension. However, to our knowledge, there is no published clinical evidence supporting these hypotheses. The current study aimed to evaluate the mediolateral excursion of the bearing during flexion-extension motion of the knee after medial unicompartmental knee arthroplasty (UKA). In 52 knees, varus/valgus (F-VarVal) or rotational position (F-Rot) of the femoral component and relative location of the bearing were measured with the standing anteroposterior and modified axial view, respectively. We adopted the modified axial radiographs that are simple to assess the bearing position in the flexed knee. The modified axial view showed excellent inter- and intraobserver agreements. F-Rot in the modified axial view and CT showed a high agreement in terms of validity (r = 0.98; p  < 0.0001). On average, the bearing showed more medial position in extension than flexion of the knee. No correlation was found between the femoral component positions (F-VarVal and F-Rot) and mediolateral bearing excursion ( p  = 0.68 and 0.80, respectively). In conclusion, coronal location of bearing according to flexion-extension of the knee is not influenced by the coronal and axial alignment of the femoral component. With simple radiographic method, more medial position of the bearing according to flexion-extension of the knee. Our method could be used to assess axial rotation of the femoral component and spin-out phenomenon of the bearing following the medial UKA. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

The effect of a dynamic PCL brace on patellofemoral compartment pressures in PCL-and PCL/PLC-deficient knees.

PubMed

Welch, Tyler; Keller, Thomas; Maldonado, Ruben; Metzger, Melodie; Mohr, Karen; Kvitne, Ronald

2017-12-01

The natural history of posterior cruciate ligament (PCL) deficiency includes the development of arthrosis in the patellofemoral joint (PFJ). The purpose of this biomechanical study was to evaluate the hypothesis that dynamic bracing reduces PFJ pressures in PCL- and combined PCL/posterolateral corner (PLC)-deficient knees. Controlled Laboratory Study. Eight fresh frozen cadaveric knees with intact cruciate and collateral ligaments were included. PFJ pressures and force were measured using a pressure mapping system via a lateral arthrotomy at knee flexion angles of 30°, 60°, 90°, and 120° in intact, PCL-deficient, and PCL/PLC-deficient knees under a combined quadriceps/hamstrings load of 400 N/200 N. Testing was then repeated in PCL- and PCL/PLC-deficient knees after application of a dynamic PCL brace. Application of a dynamic PCL brace led to a reduction in peak PFJ pressures in PCL-deficient knees. In addition, the brace led to a significant reduction in peak pressures in PCL/PLC-deficient knees at 60°, 90°, and 120° of flexion. Application of the dynamic brace also led to a reduction in total PFJ force across all flexion angles for both PCL- and PCL/PLC-deficient knees. Dynamic bracing reduces PFJ pressures in PCL- and combined PCL/PLC-deficient knees, particularly at high degrees of knee flexion.

The influence of a powered knee-ankle-foot orthosis on walking in poliomyelitis subjects: A pilot study.

PubMed

Arazpour, Mokhtar; Moradi, Alireza; Samadian, Mohammad; Bahramizadeh, Mahmood; Joghtaei, Mahmoud; Ahmadi Bani, Monireh; Hutchins, Stephen W; Mardani, Mohammad A

2016-06-01

Traditionally, the anatomical knee joint is locked in extension when walking with a conventional knee-ankle-foot orthosis. A powered knee-ankle-foot orthosis was developed to provide restriction of knee flexion during stance phase and active flexion and extension of the knee during swing phase of gait. The purpose of this study was to determine differences of the powered knee-ankle-foot orthosis compared to a locked knee-ankle-foot orthosis in kinematic data and temporospatial parameters during ambulation. Quasi-experimental design. Subjects with poliomyelitis (n = 7) volunteered for this study and undertook gait analysis with both the powered and the conventional knee-ankle-foot orthoses. Three trials per orthosis were collected while each subject walked along a 6-m walkway using a calibrated six-camera three-dimensional video-based motion analysis system. Walking with the powered knee-ankle-foot orthosis resulted in a significant reduction in both walking speed and step length (both 18%), but a significant increase in stance phase percentage compared to walking with the conventional knee-ankle-foot orthosis. Cadence was not significantly different between the two test conditions (p = 0.751). There was significantly higher knee flexion during swing phase and increased hip hiking when using the powered orthosis. The new powered orthosis permitted improved knee joint kinematic for knee-ankle-foot orthosis users while providing knee support in stance and active knee motion in swing in the gait cycle. Therefore, the new powered orthosis provided more natural knee flexion during swing for orthosis users compared to the locked knee-ankle-foot orthosis. This orthosis has the potential to improve knee joint kinematics and gait pattern in poliomyelitis subjects during walking activities. © The International Society for Prosthetics and Orthotics 2015.

Continuous passive motion and its effects on knee flexion after total knee arthroplasty in patients with knee osteoarthritis.

PubMed

Liao, Chun-De; Huang, Yi-Ching; Lin, Li-Fong; Chiu, Yen-Shuo; Tsai, Jui-Chen; Chen, Chun-Lung; Liou, Tsan-Hon

2016-08-01

This study evaluated the effects of continuous passive motion (CPM) on accelerated flexion after total knee arthroplasty (TKA) and whether CPM application measures (i.e. initial angle and daily increment) are associated with functional outcomes. A retrospective investigation was conducted at the rehabilitation centre of a university-based teaching hospital. Patients who received CPM therapy immediately after TKA surgery were categorized into rapid-, normal-, and slow-progress groups according to their response to CPM during their acute inpatient stay. Knee pain, passive knee flexion, and knee function-measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)-were assessed preoperatively at discharge and at 3- and 6-month outpatient follow-up visits. A total of 354 patients were followed for 6 months after inpatient-stay discharge. The patients in the rapid-progress group (n = 119) exhibited significantly greater knee flexions than those in the slow-progress group did (n = 103) at the 3-month follow-up [mean difference (MD) = 10.3°, 95 % confidence interval (CI) 4.3°-16.3°, p < 0.001] and 6-month follow-up (MD = 10.9°, 95 % CI 6.3°-15.6°, p < 0.001). Significant WOMAC score differences between the rapid- and slow-progress groups were observed at the 3-month follow-up (MD = 7.2, 95 % CI 5.4-9.1, p < 0.001) and 6-month follow-up (MD = 16.1, 95 % CI 13.4-18.7, p < 0.001). CPM initial angles and rapid progress significantly predicted short- and long-term outcomes in knee flexion and WOMAC scores (p < 0.001). When CPM is used, early application with initial high flexion and rapid progress benefits knee function up to 6 months after TKA. II.

Preoperative varus-valgus kinematic pattern throughout flexion persists more strongly after cruciate-retaining than after posterior-stabilized total knee arthroplasty.

PubMed

Hino, Kazunori; Oonishi, Yoshio; Kutsuna, Tatsuhiko; Watamori, Kunihiko; Iseki, Yasutake; Kiyomatsu, Hiroshi; Watanabe, Seiji; Miura, Hiromasa

2016-08-01

Restoration of normal knee kinematics is key to improving patient satisfaction and functional outcomes after total knee arthroplasty (TKA). However, the effect of preoperative varus-valgus kinematics due to knee osteoarthritis on the postoperative kinematics is unclear. The function of the knee ligament contributes to both knee stability and kinematics. The aim of this study was to evaluate changes in varus-valgus kinematics before and after TKA using a navigation system, in addition to comparing the pre- and postoperative changes in kinematic patterns between cruciate-retaining (CR)- and posterior-stabilized (PS)-TKAs. Forty knees treated with TKA were evaluated (CR-TKA 20; PS-TKA 20). Manual mild passive knee flexion was applied while moving the leg from full extension to flexion. The varus-valgus angle was automatically measured by a navigation system at every 10° of the flexion angle, and the kinematics were evaluated. Kinematic patterns throughout flexion can be classified into five types. The pre- and postoperative kinematic patterns were similar in 60% of patients who underwent CR-TKA, whereas they were similar in only 25% of those who underwent PS-TKA. The mean change in the size of the varus-valgus angle throughout flexion did not differ between CR-TKA and PS-TKA. However, the distribution of changes in the size of the varus-valgus angle differed between CR-TKA and PS-TKA. We obtained the following results: 1) some patterns of varus-valgus kinematics are noted under unloading conditions despite recovery of neutral alignment in extension and 2) the preoperative varus-valgus kinematic pattern persisted more strongly after CR-TKA than after PS-TKA. Copyright © 2015 Elsevier B.V. All rights reserved.

Assessment of tibial rotation and meniscal movement using kinematic magnetic resonance imaging

PubMed Central

2014-01-01

Objective This work aimed to assess tibial rotations, meniscal movements, and morphological changes during knee flexion and extension using kinematic magnetic resonance imaging (MRI). Methods Thirty volunteers with healthy knees were examined using kinematic MRI. The knees were imaged in the transverse plane with flexion and extension angles from 0° to 40° and 40° to 0°, respectively. The tibial interior and exterior rotation angles were measured, and the meniscal movement range, height change, and side movements were detected. Results The tibia rotated internally (11.55° ± 3.20°) during knee flexion and rotated externally (11.40° ± 3.0°) during knee extension. No significant differences were observed between the internal and external tibial rotation angles (P > 0.05), between males and females (P > 0.05), or between the left and right knee joints (P > 0.05). The tibial rotation angle with a flexion angle of 0° to 24° differed significantly from that with a flexion angle of 24° to 40° (P < 0.01). With knee flexion, the medial and lateral menisci moved backward and the height of the meniscus increased. The movement range was greater in the anterior horn than in the posterior horn and greater in the lateral meniscus than in the medial meniscus (P < 0.01). During backward movements of the menisci, the distance between the anterior and posterior horns decreased, with the decrease more apparent in the lateral meniscus (P < 0.01). The side movements of the medial and lateral menisci were not obvious, and a smaller movement range was found than that of the forward and backward movements. Conclusion Knee flexion and extension facilitated internal and external tibial rotations, which may be related to the ligament and joint capsule structure and femoral condyle geometry. PMID:25142267

Femoral articular geometry and patellofemoral stability.

PubMed

Iranpour, Farhad; Merican, Azhar M; Teo, Seow Hui; Cobb, Justin P; Amis, Andrew A

2017-06-01

Patellofemoral instability is a major cause of anterior knee pain. The aim of this study was to examine how the medial and lateral stability of the patellofemoral joint in the normal knee changes with knee flexion and measure its relationship to differences in femoral trochlear geometry. Twelve fresh-frozen cadaveric knees were used. Five components of the quadriceps and the iliotibial band were loaded physiologically with 175N and 30N, respectively. The force required to displace the patella 10mm laterally and medially at 0°, 20°, 30°, 60° and 90° knee flexion was measured. Patellofemoral contact points at these knee flexion angles were marked. The trochlea cartilage geometry at these flexion angles was visualized by Computed Tomography imaging of the femora in air with no overlying tissue. The sulcus, medial and lateral facet angles were measured. The facet angles were measured relative to the posterior condylar datum. The lateral facet slope decreased progressively with flexion from 23°±3° (mean±S.D.) at 0° to 17±5° at 90°. While the medial facet angle increased progressively from 8°±8° to 36°±9° between 0° and 90°. Patellar lateral stability varied from 96±22N at 0°, to 77±23N at 20°, then to 101±27N at 90° knee flexion. Medial stability varied from 74±20N at 0° to 170±21N at 90°. There were significant correlations between the sulcus angle and the medial facet angle with medial stability (r=0.78, p<0.0001). These results provide objective evidence relating the changes of femoral profile geometry with knee flexion to patellofemoral stability. Copyright © 2017 Elsevier B.V. All rights reserved.

Six degree-of-freedom knee joint kinematics in obese individuals with knee pain during gait.

PubMed

Li, Jing-Sheng; Tsai, Tsung-Yuan; Felson, David T; Li, Guoan; Lewis, Cara L

2017-01-01

Knee joint pain is a common symptom in obese individuals and walking is often prescribed as part of management programs. Past studies in obese individuals have focused on standing alignment and kinematics in the sagittal and coronal planes. Investigation of 6 degree-of-freedom (6DOF) knee joint kinematics during standing and gait is important to thoroughly understand knee function in obese individuals with knee pain. This study aimed to investigate the 6DOF knee joint kinematics in standing and during gait in obese patients using a validated fluoroscopic imaging system. Ten individuals with obesity and knee pain were recruited. While standing, the knee was in 7.4±6.3°of hyperextension, 2.8±3.3° of abduction and 5.6±7.3° of external rotation. The femoral center was located 0.7±3.1mm anterior and 5.1±1.5mm medial to the tibial center. During treadmill gait, the sagittal plane motion, i.e., flexion/extension and anterior-posterior translation, showed a clear pattern. Specifically, obese individuals with knee pain maintained the knee in more flexion and more anterior tibial translation during most of the stance phase of the gait cycle and had a reduced total range of knee flexion when compared to a healthy non-obese group. In conclusion, obese individuals with knee pain used hyperextension knee posture while standing, but maintained the knee in more flexion during gait with reduced overall range of motion in the 6DOF analysis.

Six degree-of-freedom knee joint kinematics in obese individuals with knee pain during gait

PubMed Central

Li, Jing-Sheng; Tsai, Tsung-Yuan; Felson, David T.; Li, Guoan; Lewis, Cara L.

2017-01-01

Knee joint pain is a common symptom in obese individuals and walking is often prescribed as part of management programs. Past studies in obese individuals have focused on standing alignment and kinematics in the sagittal and coronal planes. Investigation of 6 degree-of-freedom (6DOF) knee joint kinematics during standing and gait is important to thoroughly understand knee function in obese individuals with knee pain. This study aimed to investigate the 6DOF knee joint kinematics in standing and during gait in obese patients using a validated fluoroscopic imaging system. Ten individuals with obesity and knee pain were recruited. While standing, the knee was in 7.4±6.3°of hyperextension, 2.8±3.3° of abduction and 5.6±7.3° of external rotation. The femoral center was located 0.7±3.1mm anterior and 5.1±1.5mm medial to the tibial center. During treadmill gait, the sagittal plane motion, i.e., flexion/extension and anterior-posterior translation, showed a clear pattern. Specifically, obese individuals with knee pain maintained the knee in more flexion and more anterior tibial translation during most of the stance phase of the gait cycle and had a reduced total range of knee flexion when compared to a healthy non-obese group. In conclusion, obese individuals with knee pain used hyperextension knee posture while standing, but maintained the knee in more flexion during gait with reduced overall range of motion in the 6DOF analysis. PMID:28339477

Effect of surgical closing in total knee arthroplasty at flexion or extension: a prospective, randomized study.

PubMed

Kömürcü, Erkam; Yüksel, Halil Yalçın; Ersöz, Murat; Aktekin, Cem Nuri; Hapa, Onur; Çelebi, Levent; Akbal, Ayla; Biçimoğlu, Ali

2014-12-01

The aim of this study was to evaluate the effect of knee position during wound closure (flexed vs. extended) in total knee arthroplasty on knee strength and function, as determined by knee society scores and isokinetic testing of extensor and flexor muscle groups. In a prospective, randomized, double-blind trial, 29 patients were divided in two groups: for Group 1 patients, surgical closing was performed with the knee extended, and for Group 2 patients, the knee flexed at 90°. All the patients were treated with the same anaesthesia method, surgical team, surgical technique, prosthesis type, and rehabilitation process. American Knee Society Score values and knee flexion degrees were recorded. Isokinetic muscle strength measurements of both knees in flexion and extension were taken using 60° and 180°/s angular velocity. The peak torque and total work values, isokinetic muscle strength differences, and total work difference values were calculated for surgically repaired and healthy knees. No significant difference in the mean American Knee Society Score values and knee flexion degrees was observed between the two groups. However, using isokinetic evaluation, a significant difference was found in the isokinetic muscle strength differences and total work difference of the flexor muscle between the two groups when patients were tested at 180°/s. Less loss of strength was detected in the isokinetic muscle strength differences of the flexor muscle in Group 2 (-4.2%) than in Group 1 (-23.1%). For patients undergoing total knee arthroplasty, post-operative flexor muscle strength is improved if the knee is flexed during wound closure. II.

Development of a subject-specific model to predict the forces in the knee ligaments at high flexion angles.

PubMed

Yang, Zhaochun; Wickwire, Alexis C; Debski, Richard E

2010-11-01

Recent clinical evidence has suggested that tasks performed in kneeling or squatting postures place the knee at a higher risk for injury because loads across the knee might overload the ligaments. The objective of this study was to develop a subject-specific model of the knee that is kinematically driven to predict the forces in the major ligaments at high flexion angles. The geometry of the femur, tibia, and fibula and the load-elongation curves representing the structural properties of the ACL, PCL, LCL, and MCL served as inputs to the model, which represented each ligament as a nonlinear elastic spring. To drive the model, kinematic data was obtained while loads were applied to the same cadaveric knee at four flexion angles. The force in each ligament during the recorded kinematic data allowed an optimization procedure to determine the location of the ligament attachment sites on each bone and their reference lengths. The optimization procedure could successfully minimize the differences between the experimental and predicted forces only when the kinematics at 90°, 120°, and 140° of flexion were utilized. This finding suggests that the ligaments at the knee function differently at high-flexion angles compared to low flexion angles and separate models must be used to examine each range of motion. In the future, the novel experimental and computational methodology will be used to construct additional models and additional knee kinematics will be input to help elucidate mechanisms of injury during tasks performed in kneeling or squatting postures.

Timing of intermittent torque control with wire-driven gait training robot lifting toe trajectory for trip avoidance.

PubMed

Miyake, Tamon; Kobayashi, Yo; Fujie, Masakatsu G; Sugano, Shigeki

2017-07-01

Gait training robots are useful for changing gait patterns and decreasing risk of trip. Previous research has reported that decreasing duration of the assistance or guidance of the robot is beneficial for efficient gait training. Although robotic intermittent control method for assisting joint motion has been established, the effect of the robot intervention timing on change of toe clearance is unclear. In this paper, we tested different timings of applying torque to the knee, employing the intermittent control of a gait training robot to increase toe clearance throughout the swing phase. We focused on knee flexion motion and designed a gait training robot that can apply flexion torque to the knee with a wire-driven system. We used a method of timing detecting for the robot conducting torque control based on information from the hip, knee, and ankle angles to establish a non-time dependent parameter that can be used to adapt to gait change, such as gait speed. We carried out an experiment in which the conditions were four time points: starting the swing phase, lifting the foot, maintaining knee flexion, and finishing knee flexion. The results show that applying flexion torque to the knee at the time point when people start lifting their toe is effective for increasing toe clearance in the whole swing phase.

Single-Leg Hop Test Performance and Isokinetic Knee Strength After Anterior Cruciate Ligament Reconstruction in Athletes

PubMed Central

Sueyoshi, Ted; Nakahata, Akihiro; Emoto, Gen; Yuasa, Tomoki

2017-01-01

Background: Isokinetic strength and hop tests are commonly used to assess athletes’ readiness to return to sport after knee surgery. Purpose/Hypothesis: The purpose of this study was to investigate the results of single-leg hop and isokinetic knee strength testing in athletes who underwent anterior cruciate ligament reconstruction (ACLR) upon returning to sport participation as well as to study the correlation between these 2 test batteries. The secondary purpose was to compare the test results by graft type (patellar tendon or hamstring). It was hypothesized that there would be no statistically significant limb difference in either isokinetic knee strength or single-leg hop tests, that there would be a moderate to strong correlation between the 2 test batteries, and that there would be no significant difference between graft types. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Twenty-nine high school and collegiate athletes who underwent ACLR participated in this study. At the time of return to full sport participation, a series of hop tests and knee extension/flexion isokinetic strength measurements were conducted. The results were analyzed using analysis of variance and Pearson correlation (r). Results: The timed 6-m hop test was the only hop test that showed a significant difference between the involved and uninvolved limbs (2.3 and 2.2 seconds, respectively; P = .02). A significant difference between limbs in knee strength was found for flexion peak torque/body weight at 180 deg/s (P = .03), flexion total work/body weight at 180 deg/s (P = .04), and flexion peak torque/body weight at 300 deg/s (P = .03). The strongest correlation between the hop tests and knee strength was found between the total distance of the hop tests and flexion total work/body weight at 300 deg/s (r = 0.69) and between the timed 6-m hop test and flexion peak torque/body weight at 300 deg/s (r = –0.54). There was no statistically significant difference in hop test performance or isokinetic knee strength between graft types. Conclusion: The single-leg hop tests and isokinetic strength measurements were both useful for a bilateral comparison of knee functional performance and strength. Knee flexion strength deficits and flexion-to-extension ratios seemed to be correlated with single-leg hop test performance. There was no difference in postoperative hop test performance or knee strength according to graft type. PMID:29164167

Biomechanical and Performance Differences Between Female Soccer Athletes in National Collegiate Athletic Association Divisions I and III

PubMed Central

Smith, Rose; Ford, Kevin R; Myer, Gregory D; Holleran, Adam; Treadway, Erin; Hewett, Timothy E

2007-01-01

Context: The recent increase in women's varsity soccer participation has been accompanied by a lower extremity injury rate that is 2 to 6 times that of their male counterparts. Objective: To define the differences between lower extremity biomechanics (knee abduction and knee flexion measures) and performance (maximal vertical jump height) between National Collegiate Athletic Association Division I and III female soccer athletes during a drop vertical jump. Design: Mixed 2 × 2 design. Setting: Research laboratory. Patients or Other Participants: Thirty-four female collegiate soccer players (Division I: n = 19; Division III: n = 15) participated in the study. The groups were similar in height and mass. Intervention(s): Each subject performed a maximal vertical jump, followed by 3 drop vertical jumps. Main Outcome Measure(s): Kinematics (knee abduction and flexion angles) and kinetics (knee abduction and flexion moments) were measured with a motion analysis system and 2 force platforms during the drop vertical jumps. Results: Knee abduction angular range of motion and knee abduction external moments were not different between groups (P > .05). However, Division I athletes demonstrated decreased knee flexion range of motion (P = .038) and greater peak external knee flexion moment (P = .009) compared with Division III athletes. Division I athletes demonstrated increased vertical jump height compared with Division III (P = .008). Conclusions: Division I athletes demonstrated different sagittal-plane mechanics than Division III athletes, which may facilitate improved performance. The similarities in anterior cruciate ligament injury risk factors (knee abduction torques and angles) may correlate with the consistent incidence of anterior cruciate ligament injury across divisions. PMID:18174935

Evaluation of the Microsoft Kinect for screening ACL injury.

PubMed

Stone, Erik E; Butler, Michael; McRuer, Aaron; Gray, Aaron; Marks, Jeffrey; Skubic, Marjorie

2013-01-01

A study was conducted to evaluate the use of the skeletal model generated by the Microsoft Kinect SDK in capturing four biomechanical measures during the Drop Vertical Jump test. These measures, which include: knee valgus motion from initial contact to peak flexion, frontal plane knee angle at initial contact, frontal plane knee angle at peak flexion, and knee-to-ankle separation ratio at peak flexion, have proven to be useful in screening for future knee anterior cruciate ligament (ACL) injuries among female athletes. A marker-based Vicon motion capture system was used for ground truth. Results indicate that the Kinect skeletal model likely has acceptable accuracy for use as part of a screening tool to identify elevated risk for ACL injury.

Intraoperative evaluation of total knee replacement: kinematic assessment with a navigation system.

PubMed

Casino, Daniela; Zaffagnini, Stefano; Martelli, Sandra; Lopomo, Nicola; Bignozzi, Simone; Iacono, Francesco; Russo, Alessandro; Marcacci, Maurilio

2009-04-01

Interest in the kinematics of reconstructed knees has increased since it was shown that the alteration of knee motion could lead to abnormal wear and damage to soft tissues. We performed intraoperative kinematic measurements using a navigation system to study knee kinematics before and after posterior substituting rotating platform total knee arthroplasty (TKA). We verified intraoperatively (1) if varus/valgus (VV) laxity and anterior/posterior (AP) laxity were restored after TKA; (2) if TKA induced abnormal femoral rollback; and (3) how tibial axial rotation was influenced by TKA throughout the range of flexion. We found that TKA improved alignment in preoperative osteoarthritic varus knees which became neutral after surgery and maintained a neutral alignment in neutral knees. The VV stability at 0 degrees was restored while AP laxity at 90 degrees significantly increased after TKA. Following TKA, the femur had an abnormal anterior translation up to 60 degrees of flexion, followed by a small rollback of 12 +/- 5 mm. TKA influenced the tibia rotation pattern during flexion, but not the total amount of internal/external rotation throughout whole range of flexion, which was preserved after TKA (6 degrees +/- 5 degrees ). This study showed that the protocol proposed might be useful to adjust knee stability at time zero and that knee kinematic outcome during total knee replacement can be monitored by a navigation system.

Semimembranosus Release for Medial Soft Tissue Balancing Does Not Weaken Knee Flexion Strength in Patients Undergoing Varus Total Knee Arthroplasty.

PubMed

Jang, Sung Won; Koh, In Jun; Kim, Man Soo; Kim, Ju Yeong; In, Yong

2016-11-01

The sequential medial release technique including semimembranosus (semiM) release is effective and safe during varus total knee arthroplasty (TKA). However, there are concerns about weakening of knee flexion strength after semiM release. We determined whether semiM release to balance the medial soft tissue decreased knee flexion strength after TKA. Fifty-nine consecutive varus knees undergoing TKA were prospectively enrolled. A 3-step sequential release protocol which consisted of release of (1) the deep medial collateral ligament (dMCL), (2) the semiM, and (3) the superficial medial collateral ligament based on medial tightness. Gap balancing was obtained after dMCL release in 31 knees. However, 28 knees required semiM release or more after dMCL release. Isometric muscle strength of the knee was compared 6 months postoperatively between the semiM release and semiM nonrelease groups. Knee stability and clinical outcomes were also compared. No differences in knee flexor or extensor peak torque were observed between the groups 6 months postoperatively (P = .322 and P = .383, respectively). No group difference was observed in medial joint opening angle on valgus stress radiographs (P = .327). No differences in the Knee Society or Western Ontario and McMaster Universities Osteoarthritis Index scores were detected between the groups (P = .840 and P = .682, respectively). These results demonstrate that semiM release as a sequential step to balance medial soft tissue in varus knees did not affect knee flexion strength after TKA. Copyright © 2016 Elsevier Inc. All rights reserved.

Differences in Lower Extremity and Trunk Kinematics between Single Leg Squat and Step Down Tasks

PubMed Central

Lewis, Cara L.; Foch, Eric; Luko, Marc M.; Loverro, Kari L.; Khuu, Anne

2015-01-01

The single leg squat and single leg step down are two commonly used functional tasks to assess movement patterns. It is unknown how kinematics compare between these tasks. The purpose of this study was to identify kinematic differences in the lower extremity, pelvis and trunk between the single leg squat and the step down. Fourteen healthy individuals participated in this research and performed the functional tasks while kinematic data were collected for the trunk, pelvis, and lower extremities using a motion capture system. For the single leg squat task, the participant was instructed to squat as low as possible. For the step down task, the participant was instructed to stand on top of a box, slowly lower him/herself until the non-stance heel touched the ground, and return to standing. This was done from two different heights (16cm and 24cm). The kinematics were evaluated at peak knee flexion as well as at 60° of knee flexion. Pearson correlation coefficients (r) between the angles at those two time points were also calculated to better understand the relationship between each task. The tasks resulted in kinematics differences at the knee, hip, pelvis, and trunk at both time points. The single leg squat was performed with less hip adduction (p ≤ 0.003), but more hip external rotation and knee abduction (p ≤ 0.030), than the step down tasks at 60° of knee flexion. These differences were maintained at peak knee flexion except hip external rotation was only significant in the 24cm step down task (p ≤ 0.029). While there were multiple differences between the two step heights at peak knee flexion, the only difference at 60° of knee flexion was in trunk flexion (p < 0.001). Angles at the knee and hip had a moderate to excellent correlation (r = 0.51–0.98), but less consistently so at the pelvis and trunk (r = 0.21–0.96). The differences in movement patterns between the single leg squat and the step down should be considered when selecting a single leg task for evaluation or treatment. The high correlation of knee and hip angles between the three tasks indicates that similar information about knee and hip kinematics was gained from each of these tasks, while pelvis and trunk angles were less well predicted. PMID:25955321

Ankle-Dorsiflexion Range of Motion and Landing Biomechanics

PubMed Central

Fong, Chun-Man; Blackburn, J. Troy; Norcross, Marc F.; McGrath, Melanie; Padua, Darin A.

2011-01-01

Abstract Context: A smaller amount of ankle-dorsiflexion displacement during landing is associated with less knee-flexion displacement and greater ground reaction forces, and greater ground reaction forces are associated with greater knee-valgus displacement. Additionally, restricted dorsiflexion range of motion (ROM) is associated with greater knee-valgus displacement during landing and squatting tasks. Because large ground reaction forces and valgus displacement and limited knee-flexion displacement during landing are anterior cruciate ligament (ACL) injury risk factors, dorsiflexion ROM restrictions may be associated with a greater risk of ACL injury. However, it is unclear whether clinical measures of dorsiflexion ROM are associated with landing biomechanics. Objective: To evaluate relationships between dorsiflexion ROM and landing biomechanics. Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: Thirty-five healthy, physically active volunteers. Intervention(s): Passive dorsiflexion ROM was assessed under extended-knee and flexed-knee conditions. Landing biomechanics were assessed via an optical motion-capture system interfaced with a force plate. Main Outcome Measure(s): Dorsiflexion ROM was measured in degrees using goniometry. Knee-flexion and knee-valgus displacements and vertical and posterior ground reaction forces were calculated during the landing task. Simple correlations were used to evaluate relationships between dorsiflexion ROM and each biomechanical variable. Results: Significant correlations were noted between extended-knee dorsiflexion ROM and knee-flexion displacement (r  =  0.464, P  =  .029) and vertical (r  =  −0.411, P  =  .014) and posterior (r  =  −0.412, P  =  .014) ground reaction forces. All correlations for flexed-knee dorsiflexion ROM and knee-valgus displacement were nonsignificant. Conclusions: Greater dorsiflexion ROM was associated with greater knee-flexion displacement and smaller ground reaction forces during landing, thus inducing a landing posture consistent with reduced ACL injury risk and limiting the forces the lower extremity must absorb. These findings suggest that clinical techniques to increase plantar-flexor extensibility and dorsiflexion ROM may be important additions to ACL injury-prevention programs. PMID:21214345

Tibiofemoral and patellofemoral joint 3D-kinematics in patients with posterior cruciate ligament deficiency compared to healthy volunteers.

PubMed

von Eisenhart-Rothe, Ruediger; Lenze, Ulrich; Hinterwimmer, Stefan; Pohlig, Florian; Graichen, Heiko; Stein, Thomas; Welsch, Frederic; Burgkart, Rainer

2012-11-26

The posterior cruciate ligament (PCL) plays an important role in maintaining physiological kinematics and function of the knee joint. To date mainly in-vitro models or combined magnetic resonance and fluoroscopic systems have been used for quantifying the importance of the PCL. We hypothesized, that both tibiofemoral and patellofemoral kinematic patterns are changed in PCL-deficient knees, which is increased by isometric muscle flexion. Therefore the aim of this study was to simultaneously investigate tibiofemoral and patellofemoral 3D kinematics in patients suffering from PCL deficiency during different knee flexion angles and under neuromuscular activation. We enrolled 12 patients with isolated PCL-insufficiency as well as 20 healthy volunteers. Sagittal MR-images of the knee joint were acquired in different positions of the knee joint (0°, 30°, 90° flexion, with and without flexing isometric muscle activity) on a 0.2 Tesla open MR-scanner. After segmentation of the patella, femur and tibia local coordinate systems were established to define the spatial position of these structures in relation to each other. At full extension and 30° flexion no significant difference was observed in PCL-deficient knee joints neither for tibiofemoral nor for patellofemoral kinematics. At 90° flexion the femur of PCL-deficient patients was positioned significantly more anteriorly in relation to the tibia and both, the patellar tilt and the patellar shift to the lateral side, significantly increased compared to healthy knee joints. While no significant effect of isometric flexing muscle activity was observed in healthy individuals, in PCL-deficient knee joints an increased paradoxical anterior translation of the femur was observed at 90° flexion compared to the status of muscle relaxation. Significant changes in tibiofemoral and patellofemoral joint kinematics occur in patients with isolated PCL-insufficiency above 30 degrees of flexion compared to healthy volunteers. Since this could be one reasonable mechanism in the development of osteoarthritis (OA) our results might help to understand the long-term development of tibiofemoral and/or patellofemoral OA in PCL-insufficient knee joints.

The Incidence and Short Term Functional Effect of Partial PCL Release in Fixed and Mobile Bearing PCL Retaining TKA.

PubMed

Schwarzkopf, Ran; Woolwine, Spencer; Josephs, Lee; Scott, Richard D

2015-12-01

Posterior cruciate ligament (PCL) release may be required to balance the flexion gap in PCL retaining TKA. This study examines the incidence and functional consequences of PCL release in both fixed and mobile bearing TKA. A consecutive series of 1388 TKAs with 1014 fixed bearing, and 374 mobile bearing implants were reviewed for prevalence of partial PCL release, restoration of potential flexion and objective knee stability at minimum one-year follow-up. Patients receiving mobile bearing inserts were more likely to need partial PCL release (42% versus 17.5%). The occurrence of partial PCL release did not have a significant impact on knee range of motion and subjective knee stability. The need for a partial PCL release appears to be greater in mobile than in fixed bearing. Knees that required a release in both groups demonstrated no difference in restoration of flexion compared with unreleased knees and no adverse effects on flexion stability. Copyright © 2015 Elsevier Inc. All rights reserved.

Association of lower extremity range of motion and muscle strength with physical performance of community-dwelling older women.

PubMed

Jung, Hungu; Yamasaki, Masahiro

2016-12-08

Reduced lower extremity range of motion (ROM) and muscle strength are related to functional disability in older adults who cannot perform one or more activities of daily living (ADL) independently. The purpose of this study was to determine which factors of seven lower extremity ROMs and two muscle strengths play dominant roles in the physical performance of community-dwelling older women. Ninety-five community-dwelling older women (mean age ± SD, 70.7 ± 4.7 years; age range, 65-83 years) were enrolled in this study. Seven lower extremity ROMs (hip flexion, hip extension, knee flexion, internal and external hip rotation, ankle dorsiflexion, and ankle plantar flexion) and two muscle strengths (knee extension and flexion) were measured. Physical performance tests, including functional reach test (FRT), 5 m gait test, four square step test (FSST), timed up and go test (TUGT), and five times sit-to-stand test (FTSST) were performed. Stepwise regression models for each of the physical performance tests revealed that hip extension ROM and knee flexion strength were important explanatory variables for FRT, FSST, and FTSST. Furthermore, ankle plantar flexion ROM and knee extension strength were significant explanatory variables for the 5 m gait test and TUGT. However, ankle dorsiflexion ROM was a significant explanatory variable for FRT alone. The amount of variance on stepwise multiple regression for the five physical performance tests ranged from 25 (FSST) to 47% (TUGT). Hip extension, ankle dorsiflexion, and ankle plantar flexion ROMs, as well as knee extension and flexion strengths may play primary roles in the physical performance of community-dwelling older women. Further studies should assess whether specific intervention programs targeting older women may achieve improvements in lower extremity ROM and muscle strength, and thereby play an important role in the prevention of dependence on daily activities and loss of physical function, particularly focusing on hip extension, ankle dorsiflexion, and ankle plantar flexion ROMs as well as knee extension and flexion strength.

Effect of Rhythmic Auditory Stimulation on Hemiplegic Gait Patterns

PubMed Central

Shin, Yoon-Kyum; Chong, Hyun Ju

2015-01-01

Purpose The purpose of our study was to investigate the effect of gait training with rhythmic auditory stimulation (RAS) on both kinematic and temporospatial gait patterns in patients with hemiplegia. Materials and Methods Eighteen hemiplegic patients diagnosed with either cerebral palsy or stroke participated in this study. All participants underwent the 4-week gait training with RAS. The treatment was performed for 30 minutes per each session, three sessions per week. RAS was provided with rhythmic beats using a chord progression on a keyboard. Kinematic and temporospatial data were collected and analyzed using a three-dimensional motion analysis system. Results Gait training with RAS significantly improved both proximal and distal joint kinematic patterns in hip adduction, knee flexion, and ankle plantar flexion, enhancing the gait deviation index (GDI) as well as ameliorating temporal asymmetry of the stance and swing phases in patients with hemiplegia. Stroke patients with previous walking experience demonstrated significant kinematic improvement in knee flexion in mid-swing and ankle dorsiflexion in terminal stance. Among stroke patients, subacute patients showed a significantly increased GDI score compared with chronic patients. In addition, household ambulators showed a significant effect on reducing anterior tilt of the pelvis with an enhanced GDI score, while community ambulators significantly increased knee flexion in mid-swing phase and ankle dorsiflexion in terminal stance phase. Conclusion Gait training with RAS has beneficial effects on both kinematic and temporospatial patterns in patients with hemiplegia, providing not only clinical implications of locomotor rehabilitation with goal-oriented external feedback using RAS but also differential effects according to ambulatory function. PMID:26446657

Characterizing the recovery trajectories of knee range of motion for one year after total knee replacement.

PubMed

Mehta, Saurabh; Rigney, Andrew; Webb, Kyle; Wesney, Jacob; Stratford, Paul W; Shuler, Franklin D; Oliashirazi, Ali

2018-06-13

Retrospective analysis of routinely collected clinical data. This study modeled the recovery in knee flexion and extension range of motion (ROM) over 1 year after total knee replacement (TKR). Recovery after TKR has been characterized for self-reported pain and functional status. Literature describing target knee ROM at different follow-up periods after TKR is scarce. Data were extracted for patients who had undergone TKR at a tertiary care hospital at 2, 8, 12, 26, and 52 weeks after TKR. A linear mixed-effects growth model was constructed that investigated the following covariates age, sex, pre-TKR range, body mass index, duration of symptoms, and their interaction with weeks post TKR. Of the 559 patients included (age 64.8 ± 8.5 years), 370 were women and 189 were men. Knee ROM showed the greatest change during the first 12 weeks after TKR, plateauing by 26 weeks. For an average patient, knee flexion increased from approximately 100º 2 weeks post TKR to 117º 52 weeks post TKR. Knee extension increased from approximately 3º knee flexion 2 weeks post TKR to 1º flexion 52 weeks post TKR. The results showed that the maximum gains in knee ROM should be expected within the first 12 weeks with small changes occurring up to 26 weeks after TKR. In addition, age and presurgery knee ROM are associated with the gains in knee ROM and should be factored into the estimation of expected knee ROM at a given follow-up interval after TKR.

Changes of contact pressure and area in patellofemoral joint after different meniscectomies.

PubMed

Bai, Bo; Shun, Hui; Yin, Zhi Xun; Liao, Zhuang-Wen; Chen, Ni

2012-05-01

We investigated the contact pressure and area of the patellofemoral joint both before and after different meniscectomies to provide a biomechanical basis for selecting meniscectomy and its clinical application for meniscus injuries. Six fresh cadaveric knees were used in the study. Using Staubli robots and an ultra-low-min-type pressure-sensitive tablet, changes in contact area and stress in the patellofemoral joint were measured at various flexion angles following different parts and degrees of meniscectomy. The patellofemoral contact area enlarged with the increase of knee flexion angle. From the values obtained from contact areas and average contact pressure of the patellofemoral joint, we found no significant difference between partial meniscectomy and intact knees, but a significant difference was found between total meniscectomy and intact knees. The contact area after lateral meniscectomy was statistically less than that of intact knees. The mean patellofemoral contact pressure after lateral meniscectomy was larger than in intact knees at each angle of flexion. No significant difference in contact area was observed between intact knees and medial meniscectomy. The average patellofemoral contact pressure after medial meniscectomy was larger than in intact knees from 0° ~ 30° of knee flexion, and no significant differences were found between intact knees and medial meniscectomy while knee bending from 60° to 90°. Different meniscectomies result in high contact pressure or disordered distribution of contact pressure, which may be the cause of postoperative patellofemoral degenerative arthrosis.

Measurement of knee joint gaps without bone resection: "physiologic" extension and flexion gaps in total knee arthroplasty are asymmetric and unequal and anterior and posterior cruciate ligament resections produce different gap changes.

PubMed

Nowakowski, Andrej Maria; Majewski, Martin; Müller-Gerbl, Magdalena; Valderrabano, Victor

2012-04-01

General agreement is that flexion and extension gaps should be equal and symmetrical in total knee arthroplasty (TKA) procedures. However, comparisons using a standard TKA approach to normal knee joints that have not undergone bone resection are currently unavailable. Since bony preparation can influence capsule and ligament tension, our purpose was to perform measurements without this influence. Ten normal cadaveric knees were assessed using a standard medial parapatellar TKA approach with patellar subluxation. Gap measurements were carried out twice each alternating 100 and 200 N per compartment using a prototypical force-determining ligament balancer without the need for bony resection. Initial measurements were performed in extension, followed by 908 of flexion. The ACL was then resected, and finally the PCL was resected, and measurements were carried out in an analogous fashion. In general, the lateral compartment could be stretched further than the medial compartment, and the corresponding flexion gap values were significantly larger. ACL resection predominantly increased extension gaps, while PCL resection increased flexion gaps. Distraction force of 100 N per compartment appeared adequate; increasing to 200 N did not improve the results.

A Study of Knee Joint Kinematics and Mechanics using a Human FE Model.

PubMed

Kitagawa, Yuichi; Hasegawa, Junji; Yasuki, Tsuyoshi; Iwamoto, Masami; Miki, Kazuo

2005-11-01

Posterior translation of the tibia with respect to the femur can stretch the posterior cruciate ligament (PCL). Fifteen millimeters of relative displacement between the femur and tibia is known as the Injury Assessment Reference Value (IARV) for the PCL injury. Since the anterior protuberance of the tibial plateau can be the first site of contact when the knee is flexed, the knee bolster is generally designed with an inclined surface so as not to directly load the projection in frontal crashes. It should be noted, however, that the initial flexion angle of the occupant knee can vary among individuals and the knee flexion angle can change due to the occupant motion. The behavior of the tibial protuberance related to the knee flexion angle has not been described yet. The instantaneous angle of the knee joint at the timing of restraining the knee should be known to manage the geometry and functions of knee restraint devices. The purposes of this study are first to understand the kinematics of the knee joint during flexion, and second to characterize the mechanics of the knee joint under anterior-posterior loading. A finite element model of the knee joint, extracted from the Total Human Model for Safety (THUMS), was used to analyze the mechanism. The model was validated against kinematics and mechanical responses of the human knee joint. By tracking the relative positions and angles between the patella and the tibia in a knee flexing simulation, the magnitude of the tibial anterior protuberance was described as a function of the knee joint angle. The model revealed that the mechanics of the knee joint was characterized as a combination of stiffness of the patella-femur structure and the PCL It was also found that the magnitude of the tibial anterior protuberance determined the amount of initial stretch of the PCL in anterior-posterior loading. Based on the knee joint kinematics and mechanics, an interference boundary was proposed for different knee flexion angles, so as not to directly load the anterior protuberance of the tibial plateau in restraining of the knee. A frontal crash simulation was performed using a partial vehicle model with the THUMS seated. The performance and effects of the knee airbag, as one of the candidates for knee restraint devices, were evaluated through the simulation.

Posterior cruciate-substituting total knee replacement recovers the flexion arc faster in the early postoperative period in knees with high varus deformity: a prospective randomized study.

PubMed

Öztürk, Alpaslan; Akalın, Yavuz; Çevik, Nazan; Otuzbir, Ali; Özkan, Yüksel; Dostabakan, Yasin

2016-07-01

Posterior cruciate retention (CR) and substitution (PS) has been controversial in knee replacement surgery. Satisfactory medium and long-term results have been reported in knees with and without deformity but there are limited studies about early functional comparison in terms of recovery of flexion arc, stair activity, walking ability and straight leg raising, especially, in early postoperative period in knees with deformity. Therefore, we aimed to compare the flexion arc in CR and PS knees in postoperative first year including early postoperative days prospectively. Consecutive patients with a deformity of >10° were included and allocated to CR and PS groups randomly. KSS and Feller-patella scores were recorded both preoperatively and postoperatively (1st, 2nd, 3rd and 12th months). Flexion and extension were measured both preoperatively and postoperatively (1st, 2nd, 3rd day and discharge day as well as 1st, 2nd, 3rd and 12th months). Visual analog scale (VAS) was recorded postoperatively at the 1st, 2nd, 3rd and discharge day and at 1st, 2nd, 3rd and 12th months. The walking ability, stair activity and straight leg raising were recorded. Patients were also examined at the last visit with minimum 7-year follow-up with KSS, Feller-patella and VAS scores. Their mean flexion arcs were measured and recorded. There were 61 TKR evaluated. KSS knee and function scores at the 3rd month and KSS Knee Score at 1st year were superior in PS knees (p = 0.029, p = 0.046, p = 0.026). Flexion arc was found larger on day 1, 2, 3 and discharge day, and at 1st, 2nd, 3rd and 12th month in PS group (p = 0.048, p = 0.002, p = 0.027, p = 0.043, p = 0.014, p = 0.003, p = 0.002, p = 0.018). Walking and stair activity showed no difference but straight leg raising was better in CR knees (p = 0.02). Mean flexion arc was larger in PS knees at the last visit after 7 years (119.0° ± 7.5° in PS and 113.8° ± 8.7° in CR, p = 0.02). There was no revision required in that time interval. The other parameters were similar between groups. PS knees gained active flexion arc faster and larger. But straight leg raising activity recovered early in CR knees. Both types of prosthesis produced satisfactory outcome. PS and CR TKRs can be performed with the same performance in osteoarthritic knees even with high varus deformity. Prospective Randomized Controlled Trial, Level II.

Does patella lowering improve crouch gait in cerebral palsy? Comparative retrospective study.

PubMed

Desailly, E; Thévenin-Lemoine, C; Khouri, N

2017-09-01

Patella lowering aims to improve quadriceps function as a means of correcting crouch gait in patients with cerebral palsy. Few studies have assessed the effects of patella lowering as a component of multilevel surgery. Including patella lowering into the components of multilevel surgery is beneficial in patients with crouch gait and patella alta. In 12 lower limbs with patella alta (Caton-Deschamps index>1.4) in 41 children with cerebral palsy, patella lowering was performed, without distal femoral extension osteotomy or hamstring release. Among limbs with similar surgical procedures (e.g., hamstring lengthening, rectus femoris transfer) except for patella lowering, controls were selected retrospectively by matching on a propensity score for patella lowering. The propensity score was computed based on preoperative knee flexion contracture, knee extension lag, and minimum knee flexion at mid-stance. Clinical and 3D kinematic data were compared between the two groups. The improvement in minimum knee flexion at mid-stance was significantly greater in the group with patellar lowering (-24°±12°vs. -12°±7°). The Gait Deviation Index improved similarly in the two groups. Knee flexion contracture improved only in the group with patellar lowering. Extension lag did not improve in either group. Peak knee flexion during the swing phase remained unchanged in both groups. Patellar lowering is effective in diminishing minimum knee flexion at mid-stance in patients with patella alta and crouch gait due to cerebral palsy. Patellar lowering has not adverse effects on gait. These findings cannot be assumed to apply to patients with normal patellar height. IV (retrospective study). Copyright © 2017. Published by Elsevier Masson SAS.

Comparison of High-Flexion Fixed-Bearing and High-Flexion Mobile-Bearing Total Knee Arthroplasties-A Prospective Randomized Study.

PubMed

Kim, Young-Hoo; Park, Jang-Won; Kim, Jun-Shik

2018-01-01

There is none, to our knowledge, about comparison of high-flexion fixed-bearing and high-flexion mobile-bearing total knee arthroplasties (TKAs) in the same patients. The purpose of this study was to determine whether clinical results; radiographic and computed tomographic scan results; and the survival rate of a high-flexion mobile-bearing TKA is better than that of a high-flexion fixed-bearing TKA. The present study consisted of 92 patients (184 knees) who underwent same-day bilateral TKA. Of those, 17 were men and 75 were women. The mean age at the time of index arthroplasty was 61.5 ± 8.3 years (range 52-65 years). The mean body mass index was 26.2 ± 3.3 kg/m 2 (range 23-34 kg/m 2 ). The mean follow-up was 11.2 years (range 10-12 years). The Knee Society knee scores (93 vs 92 points; P = .531) and function scores (80 vs 80 points; P = 1.000), WOMAC scores (14 vs 15 points; P = .972), and UCLA activity scores (6 vs 6 points; P = 1.000) were not different between the 2 groups at 12 years follow-up. There were no differences in any radiographic and CT scan parameters between the 2 groups. Kaplan-Meier survivorship of the TKA component was 98% (95% confidence interval, 93-100) in the high-flexion fixed-bearing TKA group and 99% (95% confidence interval, 94-100) in the high-flexion mobile-bearing TKA group 12 years after the operation. We found no benefit to mobile-bearing TKA in terms of pain, function, radiographic and CT scan results, and survivorship. Longer-term follow-up is necessary to prove the benefit of the high-flexion mobile-bearing TKA over the high-flexion fixed-bearing TKA. Copyright © 2017 Elsevier Inc. All rights reserved.

Factors affecting the impingement angle of fixed- and mobile-bearing total knee replacements: a laboratory study.

PubMed

Walker, Peter S; Yildirim, Gokce; Sussman-Fort, Jon; Roth, Jonathan; White, Brian; Klein, Gregg R

2007-08-01

Maximum flexion-or impingement angle-is defined as the angle of flexion when the posterior femoral cortex impacts the posterior edge of the tibial insert. We examined the effects of femoral component placement on the femur, the slope angle of the tibial component, the location of the femoral-tibial contact point, and the amount of internal or external rotation. Posterior and proximal femoral placement, a more posterior femoral-tibial contact point, and a more tibial slope all increased maximum flexion, whereas rotation reduced it. A mobile-bearing knee gave results similar to those of the fixed-bearing knee, but there was no loss of flexion in internal or external rotation if the mobile bearing moved with the femur. In the absence of negative factors, a flexion angle of 150 degrees can be reached before impingement.

Knee and Hip Joint Kinematics Predict Quadriceps and Hamstrings Neuromuscular Activation Patterns in Drop Jump Landings.

PubMed

Malfait, Bart; Dingenen, Bart; Smeets, Annemie; Staes, Filip; Pataky, Todd; Robinson, Mark A; Vanrenterghem, Jos; Verschueren, Sabine

2016-01-01

The purpose was to assess if variation in sagittal plane landing kinematics is associated with variation in neuromuscular activation patterns of the quadriceps-hamstrings muscle groups during drop vertical jumps (DVJ). Fifty female athletes performed three DVJ. The relationship between peak knee and hip flexion angles and the amplitude of four EMG vectors was investigated with trajectory-level canonical correlation analyses over the entire time period of the landing phase. EMG vectors consisted of the {vastus medialis(VM),vastus lateralis(VL)}, {vastus medialis(VM),hamstring medialis(HM)}, {hamstring medialis(HM),hamstring lateralis(HL)} and the {vastus lateralis(VL),hamstring lateralis(HL)}. To estimate the contribution of each individual muscle, linear regressions were also conducted using one-dimensional statistical parametric mapping. The peak knee flexion angle was significantly positively associated with the amplitudes of the {VM,HM} and {HM,HL} during the preparatory and initial contact phase and with the {VL,HL} vector during the peak loading phase (p<0.05). Small peak knee flexion angles were significantly associated with higher HM amplitudes during the preparatory and initial contact phase (p<0.001). The amplitudes of the {VM,VL} and {VL,HL} were significantly positively associated with the peak hip flexion angle during the peak loading phase (p<0.05). Small peak hip flexion angles were significantly associated with higher VL amplitudes during the peak loading phase (p = 0.001). Higher external knee abduction and flexion moments were found in participants landing with less flexed knee and hip joints (p<0.001). This study demonstrated clear associations between neuromuscular activation patterns and landing kinematics in the sagittal plane during specific parts of the landing. These findings have indicated that an erect landing pattern, characterized by less hip and knee flexion, was significantly associated with an increased medial and posterior neuromuscular activation (dominant hamstrings medialis activity) during the preparatory and initial contact phase and an increased lateral neuromuscular activation (dominant vastus lateralis activity) during the peak loading phase.

Posterior tibial slope impacts intraoperatively measured mid-flexion anteroposterior kinematics during cruciate-retaining total knee arthroplasty.

PubMed

Dai, Yifei; Cross, Michael B; Angibaud, Laurent D; Hamad, Cyril; Jung, Amaury; Jenny, Jean-Yves

2018-02-23

Posterior tibial slope (PTS) for cruciate-retaining (CR) total knee arthroplasty (TKA) is usually pre-determined by the surgeon. Limited information is available comparing different choices of PTS on the kinematics of the CR TKA, independent of the balancing of the extension gap. This study hypothesized that with the same balanced extension gap, the choice of PTS significantly impacts the intraoperatively measured kinematics of CR TKA. Navigated CR TKAs were performed on seven fresh-frozen cadavers with healthy knees and intact posterior cruciate ligament (PCL). A custom designed tibial baseplate was implanted to allow in situ modification of the PTS, which altered the flexion gap but maintained the extension gap. Knee kinematics were measured by performing passive range of motion (ROM) tests from full extension to 120° of flexion on the intact knee and CR TKAs with four different PTSs (1°, 4°, 7°, and 10°). The measured kinematics were compared across test conditions to assess the impact of PTS. With a consistent extension gap, the change of PTS had significant impact on the anteroposterior (AP) kinematics of the CR TKA knees in mid-flexion range (45°-90°), but not so much for the high-flexion range (90°-120°). No considerable impacts were found on internal/external (I/E) rotation and hip-knee-ankle (HKA) angle. However, the findings on the individual basis suggested the impact of PTS on I/E rotation and HKA angle may be patient-specific. The data suggested that the choice of PTS had the greatest impact on the mid-flexion AP translation among the intraoperatively measured kinematics. This impact may be considered while making surgical decisions in the context of AP kinematics. When using a tibial component designed with "center" pivoting PTS, a surgeon may be able to fine tune the PTS to achieve proper mid-flexion AP stability.

Serial casting versus stretching technique to treat knee flexion contracture in children with spina bifida: a comparative study.

PubMed

Al-Oraibi, S; Tariah, Hashem Abu; Alanazi, Abdullah

2013-01-01

Severe knee contractures that develop soon after muscle imbalance may not improve with stretching exercises and splinting. An alternative treatment is serial casting, which has been used to promote increased range of motion. The purpose of this study was to compare the effectiveness of using serial casting and passive stretching approaches to treat knee flexion contracture in children with spina bifida. In a pre/post randomized controlled study, ten participants were included in the serial casting group, while eight participants were included in the passive stretching intervention group. The degree of knee extension was measured at baseline, immediately after intervention, and at a one-year follow-up using a standard goniometer. Both groups showed significant improvements in the degree of flexion contracture at the post-treatment evaluation and the follow-up evaluation. The serial casting group showed significant improvements in knee flexion contracture at the post-treatment evaluation, t (9)=13.4, p < 0.001, and the one-year follow-up evaluation, t (9) = 7.46, p < 0.001. The passive stretching group also showed significant improvements in knee flexion contracture at the post-treatment evaluation, t (7) =2.6, p < 0.05, and the one-year follow-up evaluation, t (7) = 3.6, p < 0.05. However, statistically significant improvements in the serial casting group compared with passive stretching group in relation to the degree of flexion contracture were found at the immediate post-treatment evaluation, F(1, 15)=246, p=0.0001, and the one-year follow-up evaluation, F (1, 15)=51.5, p=0.0001. The outcomes of this study provide the first evidence that serial casting may be a useful intervention in treating knee flexion contracture in children with spina bifida. However, further investigations into serial casting, as well as investigations into the use of serial casting with other interventions, are warranted.

Longitudinal tear of the medial meniscus posterior horn in the anterior cruciate ligament-deficient knee significantly influences anterior stability.

PubMed

Ahn, Jin Hwan; Bae, Tae Soo; Kang, Ki-Ser; Kang, Soo Yong; Lee, Sang Hak

2011-10-01

Longitudinal tears of the medial meniscus posterior horn (MMPH) are commonly associated with a chronic anterior cruciate ligament (ACL) deficiency. Many studies have demonstrated the importance of the medial meniscus in terms of limiting the amount of anterior-posterior tibial translation in response to anterior tibial loads in ACL-deficient knees. An MMPH tear in an ACL-deficient knee increases the anterior-posterior tibial translation and rotatory instability. In addition, MMPH repair will restore the tibial translation to the level before the tear. Controlled laboratory study. Ten human cadaveric knees were tested sequentially using a custom testing system under 5 conditions: intact, ACL deficient, ACL deficient with an MMPH peripheral longitudinal tear, ACL deficient with an MMPH repair, and ACL deficient with a total medial meniscectomy. The knee kinematics were measured at 0°, 15°, 30°, 60°, and 90° of flexion in response to a 134-N anterior and 200-N axial compressive tibial load. The rotatory kinematics were also measured at 15° and 30° of flexion in a combined rotatory load of 5 N·m of internal tibial torque and 10 N·m of valgus torque. Medial meniscus posterior horn longitudinal tears in ACL-deficient knees resulted in a significant increase in anterior-posterior tibial translation at all flexion angles except 90° (P < .05). An MMPH repair in an ACL-deficient knee showed a significant decrease in anterior-posterior tibial translation at all flexion angles except 60° compared with the ACL-deficient/MMPH tear state (P < .05). The total anterior-posterior translation of the ACL-deficient/MMPH repaired knee was not significantly increased compared with the ACL (only)-deficient knee but was increased compared with the ACL-intact knee (P > .05). A total medial meniscectomy in an ACL-deficient knee did not increase the anterior-posterior tibial translation significantly compared with MMPH tears in ACL-deficient knees at all flexion angles (P > .05). In a combined rotatory load, tibial rotation after MMPH tears or a total medial meniscectomy in an ACL-deficient knee were not affected significantly at all flexion angles. This study shows that an MMPH longitudinal tear in an ACL-deficient knee alters the knee kinematics, particularly the anterior-posterior tibial translation. MMPH repair significantly improved anterior-posterior tibial translation in ACL-deficient knees. These findings may help improve the treatment of patients with ACL and MMPH longitudinal tear by suggesting that the medial meniscal repairs should be performed for greater longevity when combined with an ACL reconstruction.

Neuromuscular adaptations induced by adjacent joint training.

PubMed

Ema, R; Saito, I; Akagi, R

2018-03-01

Effects of resistance training are well known to be specific to tasks that are involved during training. However, it remains unclear whether neuromuscular adaptations are induced after adjacent joint training. This study examined the effects of hip flexion training on maximal and explosive knee extension strength and neuromuscular performance of the rectus femoris (RF, hip flexor, and knee extensor) compared with the effects of knee extension training. Thirty-seven untrained young men were randomly assigned to hip flexion training, knee extension training, or a control group. Participants in the training groups completed 4 weeks of isometric hip flexion or knee extension training. Standardized differences in the mean change between the training groups and control group were interpreted as an effect size, and the substantial effect was assumed to be ≥0.20 of the between-participant standard deviation at baseline. Both types of training resulted in substantial increases in maximal (hip flexion training group: 6.2% ± 10.1%, effect size = 0.25; knee extension training group: 20.8% ± 9.9%, effect size = 1.11) and explosive isometric knee extension torques and muscle thickness of the RF in the proximal and distal regions. Improvements in strength were accompanied by substantial enhancements in voluntary activation, which was determined using the twitch interpolation technique and RF activation. Differences in training effects on explosive torques and neural variables between the two training groups were trivial. Our findings indicate that hip flexion training results in substantial neuromuscular adaptations during knee extensions similar to those induced by knee extension training. © 2017 The Authors. Scandinavian Journal of Medicine & Science In Sports Published by John Wiley & Sons Ltd.

[Investigation of body weight ratios on joint structures at different knee flexion angles in patients with unilateral knee arthroplasty].

PubMed

Bakırhan, Serkan; Unver, Bayram; Karatosun, Vasfi

2013-01-01

The study aims to determine body weight ratios between extremities in patients with unilateral total knee arthroplasty (TKA) at 12 months postoperatively at the static-standing position at 30, 60 and 90 degrees of knee flexion. The study included 52 female patients (mean age 65.6±10.6 years; range 40 to 83 years) who underwent unilateral primary TKA. The force-platform was used to calculate the body-weight ratios of the patients. Body weight ratios on the operated and non-operated limbs of the unilateral TKA patients were examined at standing-static position at 30, 60 and 90 degrees of knee flexion on the force-platform according to their age and body mass index (BMI). The pain levels of the patients were evaluated using the visual analog scale. It was found that unilateral TKA patients placed their body weight on the non-operated limb more at the standing-static position, and 30, 60 and 90 degrees of knee flexion at 12 months postoperatively (p<0.05). It was also found that as the knee flexion degree increased with age, so did TKA patients place their body weight on the nonoperated limb more (p<0.05), and that BMI had no effect on the load distribution difference over the two extremities (p>0.05). During the postoperative period, load asymmetry between the two extremities in patients with unilateral TKA remains the same due to advancing age. This accelerates the osteoarthritis process on the non-operated knee. It is concluded that the age factor should be taken into account while planning physiotherapy and rehabilitation programs for unilateral TKA patients and knee exercise programs aiming to place load over the operated limb should be arranged.

Analysis of Balance Ability Dependent on the Angle of the Knee Joint in Females in Their 20s

PubMed Central

Yoon, Se-Won; Lee, Jeong-Woo; Cho, Woon-Su; Kim, An-Na; Lee, Kyung-Hee

2013-01-01

The aim of this study was to investigate how balance ability according to angle of the knee joint changes in young female adults wearing a knee orthosis. [Methods] This study was conducted with 11 healthy female adults. The subjects used a knee brace that could be set to angles of 0°, 15°, and 30° of knee flexion. The ability to balance was evaluated by balance assessment. A total of four postures were used for measurements: a forward-facing posture with the eyes open on a stable surface (NO), a forward-facing posture with the eyes closed on a stable surface (NC), a forward-facing posture with the eyes open on an unstable surface (PO), and a forward-facing posture with the eyes closed on an unstable surface (PC). [Results] Regarding the weight distribution index and stability index on a stable surface, there was no interaction according to whether there was visual deprivation or not or according to knee flexion angle. Furthermore, the stability index on an unstable surface showed no interaction according to whether there was visual deprivation or not or according to knee flexion angle. But the WDI on a stable surface showed no interaction according to whether there was visual deprivation or not or according to knee flexion angle. [Conclusion] There were significant differences in the knee extension range of motion of normal elderly people and knee osteoarthritis, and the quadriceps femoris played an important role in knee function in individuals with knee osteoarthritis. PMID:24259902

Relationships among spinal mobility and sagittal alignment of spine and lower extremity to quality of life and risk of falls.

PubMed

Ishikawa, Yoshinori; Miyakoshi, Naohisa; Hongo, Michio; Kasukawa, Yuji; Kudo, Daisuke; Shimada, Yoichi

2017-03-01

Spinal deformities can affect quality of life (QOL) and risk of falling, but no studies have explored the relationships of spinal mobility and sagittal alignment of spine and the lower extremities simultaneously. Purpose of this study is to clarify the relationship of those postural parameters to QOL and risk of falling. The study evaluated 110 subjects (41 men, 69 women; mean age, 73 years). Upright and flexion and extension angles for thoracic kyphosis, lumbar lordosis, and spinal inclination were evaluated with SpinalMouse ® . Total-body inclination and hip and knee flexion angles in upright position were measured from lateral photographs. Subjects were divided into Fallers (n=23, 21%) and Non-fallers (n=87, 79%) based on past history of falls. QOL was assessed using the Short Form 36 Health Survey (SF-36 ® ). Age, total-body inclination, spinal inclination upright and in extension, thoracic kyphosis in flexion, lumbar lordosis upright and in extension, and knee flexion correlated significantly with the SF-36. Multiple regression analysis revealed total-body inclination and knee flexion to have the most significant relationships with the SF-36. SF-36, total-body inclination, spinal inclination in extension, thoracic kyphosis in flexion, lumbar lordosis upright and in extension, and hip and knee flexion angles differed significantly between Fallers and Non-fallers (P<0.05 for all). Multivariate logistic regression analyses revealed lumbar lordosis in extension to be a significant predictor of falling (P=0.038). Forward-stooped posture and knee-flexion deformity could be important indicator of lower QOL. Moreover, limited extension in the lumbar spine could be a useful screening examination for fall prevention in the elderly. Copyright © 2017 Elsevier B.V. All rights reserved.

Randomized trial investigating the efficacy of manual lymphatic drainage to improve early outcome after total knee arthroplasty.

PubMed

Ebert, Jay R; Joss, Brendan; Jardine, Berit; Wood, David J

2013-11-01

To investigate the efficacy of manual lymphatic drainage (MLD) in the early postoperative period after total knee arthroplasty (TKA) to reduce edema and pain and improve knee range of motion. Prospective randomized controlled trial. Private hospital and functional rehabilitation clinic. Consecutive sample of patients (N=43; 53 knees) scheduled for TKA. MLD (vs no MLD) on days 2, 3, and 4 postoperatively. Both groups underwent conventional, concomitant physical therapy. Clinical assessment was undertaken pre- and postoperatively prior to and after the designated postoperative MLD sessions (days 2, 3, and 4) and at 6 weeks postsurgery. This included active knee flexion and extension range of motion, lower limb girths (ankle, midpatella, thigh, and calf), and knee pain using a numeric rating scale and the Knee Injury and Osteoarthritis Outcome Score. A significant group effect was observed for active knee flexion, with post hoc tests demonstrating a significantly greater active knee flexion in the MLD group when compared with the control (no MLD) group at the final measure prior to hospital discharge (day 4 postsurgery) and at 6 weeks postsurgery. There were no further group effects observed for the remaining patient-reported and functional outcomes. MLD in the early postoperative stages after TKA appears to improve active knee flexion up to 6 weeks postsurgery, in addition to conventional care. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Does a microprocessor-controlled prosthetic knee affect stair ascent strategies in persons with transfemoral amputation?

PubMed

Aldridge Whitehead, Jennifer M; Wolf, Erik J; Scoville, Charles R; Wilken, Jason M

2014-10-01

Stair ascent can be difficult for individuals with transfemoral amputation because of the loss of knee function. Most individuals with transfemoral amputation use either a step-to-step (nonreciprocal, advancing one stair at a time) or skip-step strategy (nonreciprocal, advancing two stairs at a time), rather than a step-over-step (reciprocal) strategy, because step-to-step and skip-step allow the leading intact limb to do the majority of work. A new microprocessor-controlled knee (Ottobock X2(®)) uses flexion/extension resistance to allow step-over-step stair ascent. We compared self-selected stair ascent strategies between conventional and X2(®) prosthetic knees, examined between-limb differences, and differentiated stair ascent mechanics between X2(®) users and individuals without amputation. We also determined which factors are associated with differences in knee position during initial contact and swing within X2(®) users. Fourteen individuals with transfemoral amputation participated in stair ascent sessions while using conventional and X2(®) knees. Ten individuals without amputation also completed a stair ascent session. Lower-extremity stair ascent joint angles, moment, and powers and ground reaction forces were calculated using inverse dynamics during self-selected strategy and cadence and controlled cadence using a step-over-step strategy. One individual with amputation self-selected a step-over-step strategy while using a conventional knee, while 10 individuals self-selected a step-over-step strategy while using X2(®) knees. Individuals with amputation used greater prosthetic knee flexion during initial contact (32.5°, p = 0.003) and swing (68.2°, p = 0.001) with higher intersubject variability while using X2(®) knees compared to conventional knees (initial contact: 1.6°, swing: 6.2°). The increased prosthetic knee flexion while using X2(®) knees normalized knee kinematics to individuals without amputation during swing (88.4°, p = 0.179) but not during initial contact (65.7°, p = 0.002). Prosthetic knee flexion during initial contact and swing were positively correlated with prosthetic limb hip power during pull-up (r = 0.641, p = 0.046) and push-up/early swing (r = 0.993, p < 0.001), respectively. Participants with transfemoral amputation were more likely to self-select a step-over-step strategy similar to individuals without amputation while using X2(®) knees than conventional prostheses. Additionally, the increased prosthetic knee flexion used with X2(®) knees placed large power demands on the hip during pull-up and push-up/early swing. A modified strategy that uses less knee flexion can be used to allow step-over-step ascent in individuals with less hip strength.

Assessing coronal laxity in extension and flexion at a minimum of 10 years after primary total knee arthroplasty.

PubMed

Yoshihara, Yasushi; Arai, Yuji; Nakagawa, Shuji; Inoue, Hiroaki; Ueshima, Keiichiro; Fujiwara, Hiroyoshi; Oda, Ryo; Taniguchi, Daigo; Kubo, Toshikazu

2016-08-01

Favourable long-term results after total knee arthroplasty (TKA) require appropriate soft tissue balance. However, the relationships between long-term results after TKA surgery and mediolateral laxities at extension and at 90° flexion remain unknown. This study therefore quantitatively assessed ligament balance at extension and at 90° knee flexion at least 10 years after primary TKA, as well as clarifying the relationships between long-term outcomes and mediolateral laxities. This study included 49 knees (19 CR type and 30 PS type) of 33 patients followed up for at least 10 years after TKA at our hospital. Plain radiographs were obtained with about 150 N of varus or valgus stress using a Telos arthrometer at extension. At 90° flexion, epicondylar views were obtained under a 1.5-kg load and with about 10 kg of varus or valgus stress. Lateral laxity of about 5° was observed in both extension and flexion, with total laxities of varus and valgus stress each less than 10°. Postoperative clinical outcomes were good, with significant improvements in extension angle, femorotibial angle, and KSS, and no loosening in any knee. Good long-term results of TKA can be obtained with a lateral laxity of about 5°, equivalent to that of healthy knees. III.

Tibiofemoral forces for the native and post-arthroplasty knee: relationship to maximal laxity through a functional arc of motion.

PubMed

Manning, William A; Ghosh, Kanishka; Blain, Alasdair; Longstaff, Lee; Deehan, David John

2017-06-01

Accurate soft tissue balance must be achieved to improve functional outcome after total knee arthroplasty (TKA). Sensor-integrated tibial trials have been introduced that allow real-time measurement of tibiofemoral kinematics during TKA. This study examined the interplay between tibiofemoral force and laxity, under defined intraoperative conditions, so as to quantify the kinematic behaviour of the CR femoral single-radius knee. TKA was undertaken in eight loaded cadaveric specimens. Computer navigation in combination with sensor data defined laxity and tibiofemoral contact force, respectively, during manual laxity testing. Fixed-effect linear modelling allowed quantification of the effect for flexion angle, direction of movement and TKA implantation upon the knee. An inverse relationship between laxity and contact force was demonstrated. With flexion, laxity increased as contact force decreased under manual stress. Change in laxity was significant beyond 30° for coronal plane laxity and beyond 60° for rotatory laxity (p < 0.01). Rotational stress in mid-flexion demonstrated the greatest mismatch in inter-compartmental forces. Contact point position over the tibial sensor demonstrated paradoxical roll-forward with knee flexion. Traditional balancing techniques may not reliably equate to uniform laxity or contact forces across the tibiofemoral joint through a range of flexion and argue for the role of per-operative sensor use to aid final balancing of the knee.

Medial meniscus posterior root tear induces pathological posterior extrusion of the meniscus in the knee-flexed position: An open magnetic resonance imaging analysis.

PubMed

Masuda, S; Furumatsu, T; Okazaki, Y; Kodama, Y; Hino, T; Kamatsuki, Y; Miyazawa, S; Ozaki, T

2018-04-10

A medial meniscus posterior root tear (MMPRT) is defined as an injury to the posterior meniscal insertion on the tibia. In MMPRT, the medial meniscus (MM) hoop function is damaged, and the MM undergoes a medial extrusion into the interior from the superior articular surface of the tibia. However, the details of MM position and movement during knee joint movement are unclear in MMPRT cases. The present study aims to evaluate MM position and movement via magnetic resonance imaging (MRI) examination of the MM posterior extrusion (MMPE) at knee flexion angles of 10° and 90°. We hypothesized that, during knee flexion, the MM will shift to the posterior and the posterior extrusion will increase compared to that when the knee is extended. Twenty-four patients were diagnosed with symptomatic MMPRT on open MRI examination. Preoperative MMPE, anteroposterior interval (API) of the MM, and MM medial extrusion (MMME) at knee flexion angles of 10° and 90° were measured. For patients with MMPRT, the MMPE increased from -4.77±1.43mm to 3.79±1.17mm (p<0.001) when the knee flexion angle increased from 10° to 90°. Further, flexing the knee from 10° to 90° decreased the API of the MM from 20.19±4.22mm to 16.41±5.14mm (p<0.001). MMME showed no significant change between knee flexion angles of 10° and 90°. This study demonstrated that, in cases of MMPRT, the MMPE clearly increases when the knee is flexed to 90°, while MMME does not change. Our results suggest that open MRI examination can be used to evaluate the dynamic position of the posterior MM by scanning the knee as it flexes to 90°. IV: retrospective cohort study. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Comparison of in situ forces and knee kinematics in anteromedial and high anteromedial bundle augmentation for partially ruptured anterior cruciate ligament.

PubMed

Xu, Yan; Liu, Jianyu; Kramer, Scott; Martins, Cesar; Kato, Yuki; Linde-Rosen, Monica; Smolinski, Patrick; Fu, Freddie H

2011-02-01

High tunnel placement is common in single- and double-bundle anterior cruciate ligament (ACL) reconstructions. Similar nonanatomic tunnel placement may also occur in ACL augmentation surgery. In this study, in situ forces and knee kinematics were compared between nonanatomic high anteromedial (AM) and anatomic AM augmentation in a knee with isolated AM bundle injury. Controlled laboratory study. Seven fresh-frozen cadaver knees were used (age, 48 ± 12.5 years). First, intact knee kinematics was tested with a robotic-universal force sensor testing system under 2 loading conditions. An 89-N anterior load was applied, and an anterior tibial translation was measured at knee flexion angles of 0°, 30°, 60°, and 90°. Then, combined rotatory loads of 7-N·m valgus and 5-N·m internal tibial rotation were applied at 15° and 30° of knee flexion angles, which mimic the pivot shift. Afterward, only the AM bundle of the ACL was cut arthroscopically, keeping the posterolateral bundle intact. The knee was again tested using the intact knee kinematics to measure the in situ force of the AM bundle. Then, arthroscopic anatomic AM bundle reconstruction was performed with an allograft, and the knee was tested to give the in situ force of the reconstructed AM bundle. Knee kinematics under the 3 conditions (intact, anatomic AM augmentation, and nonanatomic high AM augmentation) and the in situ force were compared and analyzed. The high AM graft had significantly lower in situ force than the intact and anatomic reconstructed AM bundle at 0° of knee flexion (P < .05) and the intact AM bundle at 30° of knee flexion under anterior tibial loading. There were no differences between anatomic graft and intact AM bundle. The high AM graft also had a significantly lower in situ force than the intact and anatomic reconstructed AM with simulated pivot-shift loading at 15° and 30° of flexion (P < .05). Under anterior tibial and rotatory loading, there was a difference in tibial displacement between anatomic and high AM reconstructions and between the high AM graft and intact ACL under rotational loading with the knee at 15° of flexion. Anatomic AM augmentation can lead to biomechanical advantages at time zero when compared with the nonanatomic (high AM) augmentation. Anatomic AM augmentation better restores the knee kinematics to the intact ACL state.

Altered Knee and Ankle Kinematics During Squatting in Those With Limited Weight-Bearing–Lunge Ankle-Dorsiflexion Range of Motion

PubMed Central

Dill, Karli E.; Begalle, Rebecca L.; Frank, Barnett S.; Zinder, Steven M.; Padua, Darin A.

2014-01-01

Context: Ankle-dorsiflexion (DF) range of motion (ROM) may influence movement variables that are known to affect anterior cruciate ligament loading, such as knee valgus and knee flexion. To our knowledge, researchers have not studied individuals with limited or normal ankle DF-ROM to investigate the relationship between those factors and the lower extremity movement patterns associated with anterior cruciate ligament injury. Objective: To determine, using 2 different measurement techniques, whether knee- and ankle-joint kinematics differ between participants with limited and normal ankle DF-ROM. Design: Cross-sectional study. Setting: Sports medicine research laboratory. Patients or Other Participants: Forty physically active adults (20 with limited ankle DF-ROM, 20 with normal ankle DF-ROM). Main Outcome Measure(s): Ankle DF-ROM was assessed using 2 techniques: (1) nonweight-bearing ankle DF-ROM with the knee straight, and (2) weight-bearing lunge (WBL). Knee flexion, knee valgus-varus, knee internal-external rotation, and ankle DF displacements were assessed during the overhead-squat, single-legged squat, and jump-landing tasks. Separate 1-way analyses of variance were performed to determine whether differences in knee- and ankle-joint kinematics existed between the normal and limited groups for each assessment. Results: We observed no differences between the normal and limited groups when classifying groups based on nonweight-bearing passive-ankle DF-ROM. However, individuals with greater ankle DF-ROM during the WBL displayed greater knee-flexion and ankle-DF displacement and peak knee flexion during the overhead-squat and single-legged squat tasks. In addition, those individuals also demonstrated greater knee-varus displacement during the single-legged squat. Conclusions: Greater ankle DF-ROM assessed during the WBL was associated with greater knee-flexion and ankle-DF displacement during both squatting tasks as well as greater knee-varus displacement during the single-legged squat. Assessment of ankle DF-ROM using the WBL provided important insight into compensatory movement patterns during squatting, whereas nonweight-bearing passive ankle DF-ROM did not. Improving ankle DF-ROM during the WBL may be an important intervention for altering high-risk movement patterns commonly associated with noncontact anterior cruciate ligament injury. PMID:25144599

Altered knee and ankle kinematics during squatting in those with limited weight-bearing-lunge ankle-dorsiflexion range of motion.

PubMed

Dill, Karli E; Begalle, Rebecca L; Frank, Barnett S; Zinder, Steven M; Padua, Darin A

2014-01-01

Ankle-dorsiflexion (DF) range of motion (ROM) may influence movement variables that are known to affect anterior cruciate ligament loading, such as knee valgus and knee flexion. To our knowledge, researchers have not studied individuals with limited or normal ankle DF-ROM to investigate the relationship between those factors and the lower extremity movement patterns associated with anterior cruciate ligament injury. To determine, using 2 different measurement techniques, whether knee- and ankle-joint kinematics differ between participants with limited and normal ankle DF-ROM. Cross-sectional study. Sports medicine research laboratory. Forty physically active adults (20 with limited ankle DF-ROM, 20 with normal ankle DF-ROM). Ankle DF-ROM was assessed using 2 techniques: (1) nonweight-bearing ankle DF-ROM with the knee straight, and (2) weight-bearing lunge (WBL). Knee flexion, knee valgus-varus, knee internal-external rotation, and ankle DF displacements were assessed during the overhead-squat, single-legged squat, and jump-landing tasks. Separate 1-way analyses of variance were performed to determine whether differences in knee- and ankle-joint kinematics existed between the normal and limited groups for each assessment. We observed no differences between the normal and limited groups when classifying groups based on nonweight-bearing passive-ankle DF-ROM. However, individuals with greater ankle DF-ROM during the WBL displayed greater knee-flexion and ankle-DF displacement and peak knee flexion during the overhead-squat and single-legged squat tasks. In addition, those individuals also demonstrated greater knee-varus displacement during the single-legged squat. Greater ankle DF-ROM assessed during the WBL was associated with greater knee-flexion and ankle-DF displacement during both squatting tasks as well as greater knee-varus displacement during the single-legged squat. Assessment of ankle DF-ROM using the WBL provided important insight into compensatory movement patterns during squatting, whereas nonweight-bearing passive ankle DF-ROM did not. Improving ankle DF-ROM during the WBL may be an important intervention for altering high-risk movement patterns commonly associated with noncontact anterior cruciate ligament injury.

Obliteration of Intercondylar Notch Mimicking Flexion-Extension Gap Imbalance in a Cruciate Retaining Total Knee Arthroplasty

PubMed Central

Gungor, Harun Resit; Kiter, Esat; Akkaya, Semih; Ok, Nusret; Yorukoglu, Cagdas

2015-01-01

Following total knee arthroplasty (TKA), the most frequent cause of extension deficit and limitation of range of motion in early postoperative period is related to improper tensioning of soft tissues and failure to balance extension and flexion gaps. If a cruciate retaining (CR) prosthesis is the planned implant, then attention should be given to balancing the posterior cruciate ligament (PCL), and any factor that alters this balance may also cause deterioration of knee balance in postoperative period. Here, we report on an unusual case referred from another hospital because of continuous pain and restriction of knee motion in early postoperative period following CR-designed TKA that was initially thought to be due to flexion-extension imbalance. However, during the revision procedure, extruded cement to the intercondylar notch was found to be both mechanically blocking terminal extension and limiting flexion by possible mechanism of irritation of the synovial nerve endings around the stretched anterior fibers of PCL during flexion. This case was successfully treated by removal of extruded cement from intercondylar notch to decompress PCL, polyethylene exchange, and secondary patellar resurfacing. PMID:26185697

What is the normal response to structural differentiation within the slump and straight leg raise tests?

PubMed

Herrington, Lee; Bendix, Katie; Cornwell, Catherine; Fielden, Nicola; Hankey, Karen

2008-08-01

The purpose of the study was to assess the effect of structural differentiation or sensitising manoeuvres on responses of normal subjects to standard neurodynamic tests of straight leg raise (SLR) and slump test. Eighty-eight (39 males and 49 females) asymptomatic subjects were examined (aged 18-39 mean age 21.9+/-4.1 years). Knee flexion angle was measured using a goniometer during the slump test in two conditions cervical flexion and extension. Hip flexion angle was measured using a goniometer during SLR test in two conditions; ankle dorsi-flexion and neutral. The change in knee flexion, following addition of the structural differentiating manoeuvre to the slump test, was a significant increase in knee flexion angle for both males (change in knee angle; 6.6+/-4.7 degrees /18.7+/-17.5%, p<0.01) and females (change in knee angle 5.4+/-5.8 degrees /17.6+/-23.7%, p<0.01), though showed no difference between sides (p>0.05). During the SLR test, a significant reduction in hip flexion occurred following structural differentiation for both groups (change in hip angle; males = 9.5+/-8.3 degrees /21.5+/-18.8%, p<0.01; females = 15.2+/-9.5 degrees /25.9+/-13.9%, p<0.01), though showed no difference between sides (p>0.05). Structural differentiating manoeuvres have a significant effect on test response in terms of range of movement even in normal asymptomatic individuals. These responses should be taken into account during the assessment clinical reasoning process.

Upright Magnetic Resonance Imaging Tasks in the Knee Osteoarthritis Population: Relationships Between Knee Flexion Angle, Self-Reported Pain, and Performance.

PubMed

Gade, Venkata; Allen, Jerome; Cole, Jeffrey L; Barrance, Peter J

2016-07-01

To characterize the ability of patients with symptomatic knee osteoarthritis (OA) to perform a weight-bearing activity compatible with upright magnetic resonance imaging (MRI) scanning and how this ability is affected by knee pain symptoms and flexion angles. Cross-sectional observational study assessing effects of knee flexion angle, pain level, and study sequence on accuracy and duration of performing a task used in weight-bearing MRI evaluation. Visual feedback of knee position from an MRI compatible sensor was provided. Pain levels were self-reported on a standardized scale. Simulated MRI setup in a research laboratory. Convenience sample of individuals (N=14; 9 women, 5 men; mean, 69±14y) with symptomatic knee OA. Not applicable. Averaged absolute and signed angle error from target knee flexion for each minute of trial and duration tolerance (the duration that subjects maintained position within a prescribed error threshold). Absolute targeting error increased at longer trial durations (P<.001). Duration tolerance decreased with increasing pain (mean ± SE, no pain: 3min 19s±11s; severe pain: 1min 49s±23s; P=.008). Study sequence affected duration tolerance (first knee: 3min 5s±9.1s; second knee: 2min 19s±9.7s; P=.015). The study provided evidence that weight-bearing MRI evaluations based on imaging protocols in the range of 2 to 3 minutes are compatible with patients reporting mild to moderate knee OA-related pain. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Innovative application of Cox Flexion Distraction Decompression to the knee: a retrospective case series

PubMed Central

Albano, Luigi

2017-01-01

Objective The purpose of this study is to introduce the application of Cox flexion distraction decompression as an innovative approach to treating knee pain and osteoarthritis. Methods Six months of clinical files from one chiropractic practice were retrospectively screened for patients who had been treated for knee pain. Twenty-five patients met the criteria for inclusion. The treatment provided was Cox flexion distraction decompression. Pre-treatment and post-treatment visual analog pain scales (VAS) were used to measure the results. In total, eight patients presented with acute knee pain (less than three months’ duration) and 18 patients presented with chronic knee pain (greater than three months) including two patients with continued knee pain after prosthetic replacement surgery. Results For all 25 patients, a change was observed in the mean VAS scores from 7.7 to 1.8. The mean number of treatments was 5.3 over an average of 3.0 weeks. Acute patient mean VAS scores dropped from 8.1 to 1.1 within 4.8 treatments over 2.4 weeks. Chronic patient mean VAS scores dropped from 7.5 to 2.2 within 5.4 treatments over 3.3 weeks. No adverse events were reported. Conclusion This study showed clinical improvement in patients with knee pain who were managed with Cox flexion distraction decompression applied to the knee. PMID:28928498

Comparison of erector spinae and hamstring muscle activities and lumbar motion during standing knee flexion in subjects with and without lumbar extension rotation syndrome.

PubMed

Kim, Si-hyun; Kwon, Oh-yun; Park, Kyue-nam; Kim, Moon-Hwan

2013-12-01

The aim of this study was to compare the activity of the erector spinae (ES) and hamstring muscles and the amount and onset of lumbar motion during standing knee flexion between individuals with and without lumbar extension rotation syndrome. Sixteen subjects with lumbar extension rotation syndrome (10 males, 6 females) and 14 healthy subjects (8 males, 6 females) participated in this study. During the standing knee flexion, surface electromyography (EMG) was used to measure muscle activity, and surface EMG electrodes were attached to both the ES and hamstring (medial and lateral) muscles. A three-dimensional motion analysis system was used to measure kinematic data of the lumbar spine. An independent-t test was conducted for the statistical analysis. The group suffering from lumbar extension rotation syndrome exhibited asymmetric muscle activation of the ES and decreased hamstring activity. Additionally, the group with lumbar extension rotation syndrome showed greater and earlier lumbar extension and rotation during standing knee flexion compared to the control group. These data suggest that asymmetric ES muscle activation and a greater amount of and earlier lumbar motion in the sagittal and transverse plane during standing knee flexion may be an important factor contributing to low back pain. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparing the effects of mechanical perturbation training with a compliant surface and manual perturbation training on joints kinematics after ACL-rupture.

PubMed

Nawasreh, Zakariya; Failla, Mathew; Marmon, Adam; Logerstedt, David; Snyder-Mackler, Lynn

2018-05-23

Performing physical activities on a compliant surface alters joint kinematics and increases joints stiffness. However, the effect of compliant surface on joint kinematics after ACL-rupture is yet unknown. To compare the effects of mechanical perturbation training with a compliant surface to manual perturbation training on joint kinematics after ACL-rupture. Sixteen level I/II athletes with ACL-rupture participated in this preliminary study. Eight patients received mechanical perturbation with compliant surface (Mechanical) and 8 patients received manual perturbation training (Manual). Patients completed standard gait analysis before (Pre) and after (Post) training. Significant group-by-time interactions were found for knee flexion angle at initial contact (IC) and peak knee flexion (PKF) (p<0.004), with manual group significantly increased knee flexion angle at IC and PKF (p<0.03). Main effects of group were found for hip flexion angle at IC (Manual:34.34+3.51°, Mechanical:27.68+4.08°, p = 0.011), hip rotation angle at PKE (Manual:-3.40+4.78°, Mechanical:5.43+4.78°, p < 0.0001), and knee adduction angle at PKE (Manual:-2.00+2.23°, Mechanical:0.55+2.23°, p = 0.039). Main effects of time were found for hip adduction angle at PKE (Pre:6.98+4.48°, Post:8.41+4.91°, p = 0.04), knee adduction angle at IC (Pre:-2.90+3.50°, Post:-0.62+2.58°, p = 0.03), ankle adduction angle at IC (Pre:2.16+3.54, Post:3.8+3.68, p = 0.008), and ankle flexion angle at PKF (Pre:-4.55+2.77°, Post:-2.39+3.48°, p = 0.01). Training on a compliant surface induces different effects on joint kinematics compared to manual perturbation training after ACL-rupture. Manual perturbation improved hip alignment and increased knee flexion angles, while mechanical training decreased knee flexion angles throughout the stance phase. Administering training on a compliant surface after ACL-rupture may help improving dynamic knee stability, however, long-term effects on knee health needs to be determined. Copyright © 2018 Elsevier B.V. All rights reserved.

Trapezoid supracondylar femoral extension osteotomy for knee flexion contractures in patients with haemophilia.

PubMed

Mortazavi, S M J; Heidari, P; Esfandiari, H; Motamedi, M

2008-01-01

Flexion deformity of the haemophilic knee is a considerable cause of disability and may need to be managed surgically in severe cases. We have used a trapezoid supracondylar femoral extension osteotomy to correct severe knee flexion deformity. Nine severe haemophilic patients with contractures >30 degrees that were unresponsive to conservative measures underwent 11 trapezoid osteotomies. The angle of deformity was measured using anteroposterior and lateral knee X-ray films at maximum extension. Factor levels of 80-100% were achieved before the operation. A trapezoid osteotomy of the distal femur bone was performed using a lateral approach. The frontal plane angular deformity (if any) was corrected at the same time. The osteotomy site was fixed using an Arbeitsgemeinschaft für Osteo synthesefragen (AO) condylar blade plate. Following surgery, the knee was supported by a plaster splint at 20 degrees of flexion. Physiotherapy was started on third postoperative day and continued three times a week. There was no serious complication. The deformities were corrected in all of the patients and the mean range of motion increased form 68.6 degrees to 98.1 degrees . Bleeding episodes decreased in all four knees which had a bleeding score of 3 before surgery. Using the Orthopaedic Advisory Committee of the World Federation of Haemophilia scores, nine good and two fair results were obtained. All patients regained the ability to walk for both short and long distance without any aid, climb the stairs, bath, and use public transportation. Trapezoid supracondylar femoral extension osteotomy should be considered in the surgical management of severe haemophilic flexion deformity of the knee joint.

Non-invasive, non-radiological quantification of anteroposterior knee joint ligamentous laxity

PubMed Central

Russell, D. F.; Deakin, A. H.; Fogg, Q. A.; Picard, F.

2013-01-01

Objectives We performed in vitro validation of a non-invasive skin-mounted system that could allow quantification of anteroposterior (AP) laxity in the outpatient setting. Methods A total of 12 cadaveric lower limbs were tested with a commercial image-free navigation system using trackers secured by bone screws. We then tested a non-invasive fabric-strap system. The lower limb was secured at 10° intervals from 0° to 60° of knee flexion and 100 N of force was applied perpendicular to the tibia. Acceptable coefficient of repeatability (CR) and limits of agreement (LOA) of 3 mm were set based on diagnostic criteria for anterior cruciate ligament (ACL) insufficiency. Results Reliability and precision within the individual invasive and non-invasive systems was acceptable throughout the range of flexion tested (intra-class correlation coefficient 0.88, CR 1.6 mm). Agreement between the two systems was acceptable measuring AP laxity between full extension and 40° knee flexion (LOA 2.9 mm). Beyond 40° of flexion, agreement between the systems was unacceptable (LOA > 3 mm). Conclusions These results indicate that from full knee extension to 40° flexion, non-invasive navigation-based quantification of AP tibial translation is as accurate as the standard validated commercial system, particularly in the clinically and functionally important range of 20° to 30° knee flexion. This could be useful in diagnosis and post-operative evaluation of ACL pathology. Cite this article: Bone Joint Res 2013;2:233–7. PMID:24184443

Association of Quadriceps Strength and Psychosocial Factors With Single-Leg Hop Performance in Patients With Meniscectomy.

PubMed

Hsu, Chao-Jung; George, Steven Z; Chmielewski, Terese L

2016-12-01

Clinicians use the single-leg hop test to assess readiness for return to sports after knee injury. Few studies have reported the results of single-leg hop testing after meniscectomy. Additionally, the contributions of impairments in quadriceps strength and psychosocial factors to single-leg hop performance are unknown. To compare single-leg hop performance (distance and landing mechanics) between limbs and to examine the association of single-leg hop performance with quadriceps strength and psychosocial factors in patients with meniscectomy. Descriptive laboratory study. A total of 22 subjects who underwent meniscectomy for traumatic meniscal tears received either standard rehabilitation alone or with additional quadriceps strengthening. Testing was conducted immediately postrehabilitation and at 1 year postsurgery. A single-leg hop test was performed bilaterally, and hop distance was used to create a hop symmetry index. Landing mechanics (peak knee flexion angle, knee extension moment, and peak vertical ground-reaction force) were analyzed with a motion-capture system and a force plate. An isokinetic dynamometer (60 deg/s) assessed knee extensor peak torque and rate of torque development (RTD 0-200ms and RTD 0-peak torque ). Questionnaires assessed fear of reinjury (Tampa Scale for Kinesiophobia [TSK-11]) and self-efficacy (Knee Activity Self-Efficacy [KASE]). Rehabilitation groups did not significantly differ in single-leg hop performance; therefore, groups were combined for further analyses. The mean hop symmetry index was 88.6% and 98.9% at postrehabilitation and 1 year postsurgery, respectively. Compared with the nonsurgical limb, the surgical limb showed decreased peak knee flexion angle at postrehabilitation and decreased knee extension moment at 1 year postsurgery. The hop symmetry index was positively associated with peak torque, RTD 0-200ms , and the KASE score at postrehabilitation. Moreover, at postrehabilitation, the peak knee flexion angle was positively associated with peak torque and RTD 0-200ms , and the knee extension moment was positively associated with RTD 0-200ms . At 1 year postsurgery, peak knee flexion angle and knee extension moment were both positively associated with peak torque, RTD 0-200ms , and RTD 0-peak torque . Although the hop symmetry index could be considered satisfactory for returning to sports, asymmetries in landing mechanics still exist in the first year postmeniscectomy. Greater quadriceps strength was associated with greater single-leg hop distance and better landing mechanics at both postrehabilitation and 1 year postsurgery. Knee activity self-efficacy was the only psychosocial factor associated with single-leg hop performance and isolated to a positive association with single-leg hop distance at postrehabilitation. Rate of development is not typically measured in the clinic but can be an additional quadriceps measure to monitor for single-leg hop performance. Quadriceps strength and psychosocial factors appear to have separate influence on single-leg hop performance after meniscectomy, which has implications for developing appropriate interventions for optimal single-leg hop performance.

Association of Quadriceps Strength and Psychosocial Factors With Single-Leg Hop Performance in Patients With Meniscectomy

PubMed Central

Hsu, Chao-Jung; George, Steven Z.; Chmielewski, Terese L.

2016-01-01

Background: Clinicians use the single-leg hop test to assess readiness for return to sports after knee injury. Few studies have reported the results of single-leg hop testing after meniscectomy. Additionally, the contributions of impairments in quadriceps strength and psychosocial factors to single-leg hop performance are unknown. Purpose: To compare single-leg hop performance (distance and landing mechanics) between limbs and to examine the association of single-leg hop performance with quadriceps strength and psychosocial factors in patients with meniscectomy. Study Design: Descriptive laboratory study. Methods: A total of 22 subjects who underwent meniscectomy for traumatic meniscal tears received either standard rehabilitation alone or with additional quadriceps strengthening. Testing was conducted immediately postrehabilitation and at 1 year postsurgery. A single-leg hop test was performed bilaterally, and hop distance was used to create a hop symmetry index. Landing mechanics (peak knee flexion angle, knee extension moment, and peak vertical ground-reaction force) were analyzed with a motion-capture system and a force plate. An isokinetic dynamometer (60 deg/s) assessed knee extensor peak torque and rate of torque development (RTD0-200ms and RTD0–peak torque). Questionnaires assessed fear of reinjury (Tampa Scale for Kinesiophobia [TSK-11]) and self-efficacy (Knee Activity Self-Efficacy [KASE]). Results: Rehabilitation groups did not significantly differ in single-leg hop performance; therefore, groups were combined for further analyses. The mean hop symmetry index was 88.6% and 98.9% at postrehabilitation and 1 year postsurgery, respectively. Compared with the nonsurgical limb, the surgical limb showed decreased peak knee flexion angle at postrehabilitation and decreased knee extension moment at 1 year postsurgery. The hop symmetry index was positively associated with peak torque, RTD0-200ms, and the KASE score at postrehabilitation. Moreover, at postrehabilitation, the peak knee flexion angle was positively associated with peak torque and RTD0-200ms, and the knee extension moment was positively associated with RTD0-200ms. At 1 year postsurgery, peak knee flexion angle and knee extension moment were both positively associated with peak torque, RTD0-200ms, and RTD0–peak torque. Conclusion: Although the hop symmetry index could be considered satisfactory for returning to sports, asymmetries in landing mechanics still exist in the first year postmeniscectomy. Greater quadriceps strength was associated with greater single-leg hop distance and better landing mechanics at both postrehabilitation and 1 year postsurgery. Knee activity self-efficacy was the only psychosocial factor associated with single-leg hop performance and isolated to a positive association with single-leg hop distance at postrehabilitation. Clinical Relevance: Rate of development is not typically measured in the clinic but can be an additional quadriceps measure to monitor for single-leg hop performance. Quadriceps strength and psychosocial factors appear to have separate influence on single-leg hop performance after meniscectomy, which has implications for developing appropriate interventions for optimal single-leg hop performance. PMID:28210647

An Investigation into the Relation between the Technique of Movement and Overload in Step Aerobics

PubMed Central

Wysocka, Katarzyna

2017-01-01

The aim of this research was to determine the features of a step workout technique which may be related to motor system overloading in step aerobics. Subjects participating in the research were instructors (n = 15) and students (n = 15) without any prior experience in step aerobics. Kinematic and kinetic data was collected with the use of the BTS SMART system comprised of 6 calibrated video cameras and two Kistler force plates. The subjects' task was to perform basic steps. The following variables were analyzed: vertical, anteroposterior, and mediolateral ground reaction forces; foot flexion and abduction and adduction angles; knee joint flexion angle; and trunk flexion angle in the sagittal plane. The angle of a foot adduction recorded for the instructors was significantly smaller than that of the students. The knee joint angle while stepping up was significantly higher for the instructors compared to that for the students. Our research confirmed that foot dorsal flexion and adduction performed while stepping up increased load on the ankle joint. Both small and large angles of knee flexion while stepping up and down resulted in knee joint injuries. A small trunk flexion angle in the entire cycle of step workout shut down dorsal muscles, which stopped suppressing the load put on the spine. PMID:28348501

Body size and lower limb posture during walking in humans.

PubMed

Hora, Martin; Soumar, Libor; Pontzer, Herman; Sládek, Vladimír

2017-01-01

We test whether locomotor posture is associated with body mass and lower limb length in humans and explore how body size and posture affect net joint moments during walking. We acquired gait data for 24 females and 25 males using a three-dimensional motion capture system and pressure-measuring insoles. We employed the general linear model and commonality analysis to assess the independent effect of body mass and lower limb length on flexion angles at the hip, knee, and ankle while controlling for sex and velocity. In addition, we used inverse dynamics to model the effect of size and posture on net joint moments. At early stance, body mass has a negative effect on knee flexion (p < 0.01), whereas lower limb length has a negative effect on hip flexion (p < 0.05). Body mass uniquely explains 15.8% of the variance in knee flexion, whereas lower limb length uniquely explains 5.4% of the variance in hip flexion. Both of the detected relationships between body size and posture are consistent with the moment moderating postural adjustments predicted by our model. At late stance, no significant relationship between body size and posture was detected. Humans of greater body size reduce the flexion of the hip and knee at early stance, which results in the moderation of net moments at these joints.

Alterations in walking knee joint stiffness in individuals with knee osteoarthritis and self-reported knee instability.

PubMed

Gustafson, Jonathan A; Gorman, Shannon; Fitzgerald, G Kelley; Farrokhi, Shawn

2016-01-01

Increased walking knee joint stiffness has been reported in patients with knee osteoarthritis (OA) as a compensatory strategy to improve knee joint stability. However, presence of episodic self-reported knee instability in a large subgroup of patients with knee OA may be a sign of inadequate walking knee joint stiffness. The objective of this work was to evaluate the differences in walking knee joint stiffness in patients with knee OA with and without self-reported instability and examine the relationship between walking knee joint stiffness with quadriceps strength, knee joint laxity, and varus knee malalignment. Overground biomechanical data at a self-selected gait velocity was collected for 35 individuals with knee OA without self-reported instability (stable group) and 17 individuals with knee OA and episodic self-reported instability (unstable group). Knee joint stiffness was calculated during the weight-acceptance phase of gait as the change in the external knee joint moment divided by the change in the knee flexion angle. The unstable group walked with lower knee joint stiffness (p=0.01), mainly due to smaller heel-contact knee flexion angles (p<0.01) and greater knee flexion excursions (p<0.01) compared to their knee stable counterparts. No significant relationships were observed between walking knee joint stiffness and quadriceps strength, knee joint laxity or varus knee malalignment. Reduced walking knee joint stiffness appears to be associated with episodic knee instability and independent of quadriceps muscle weakness, knee joint laxity or varus malalignment. Further investigations of the temporal relationship between self-reported knee joint instability and walking knee joint stiffness are warranted. Copyright © 2015 Elsevier B.V. All rights reserved.

Alterations in walking knee joint stiffness in individuals with knee osteoarthritis and self-reported knee instability

PubMed Central

Gustafson, Jonathan A.; Gorman, Shannon; Fitzgerald, G. Kelley; Farrokhi, Shawn

2017-01-01

Increased walking knee joint stiffness has been reported in patients with knee osteoarthritis (OA) as a compensatory strategy to improve knee joint stability. However, presence of episodic self-reported knee instability in a large subgroup of patients with knee OA may be a sign of inadequate walking knee joint stiffness. The objective of this work was to evaluate the differences in walking knee joint stiffness in patients with knee OA with and without self-reported instability and examine the relationship between walking knee joint stiffness with quadriceps strength, knee joint laxity, and varus knee malalignment. Overground biomechanical data at a self-selected gait velocity was collected for 35 individuals with knee OA without self-reported instability (stable group) and 17 individuals with knee OA and episodic self-reported instability (unstable group). Knee joint stiffness was calculated during the weight-acceptance phase of gait as the change in the external knee joint moment divided by the change in the knee flexion angle. The unstable group walked with lower knee joint stiffness (p=0.01), mainly due to smaller heel-contact knee flexion angles (p<0.01) and greater knee flexion excursions (p<0.01) compared to their knee stable counterparts. No significant relationships were observed between walking knee joint stiffness and quadriceps strength, knee joint laxity or varus knee malalignment. Reduced walking knee joint stiffness appears to be associated with episodic knee instability and independent of quadriceps muscle weakness, knee joint laxity or varus malalignment. Further investigations of the temporal relationship between self-reported knee joint instability and walking knee joint stiffness are warranted. PMID:26481256

Measurement of Knee Rotation Angles Using a Smartphone Application: An Experimental Study of Porcine Knees.

PubMed

Kim, Hee-June; Lee, Hyun-Joo; Shin, Ji-Yeon; Choi, Young-Seo; Kyung, Hee-Soo

2017-12-01

This study evaluated the efficacy of a smartphone application in the measurement of rotation angles in porcine knees. Two K-wires were fixated to the femoral condyle and anterior tibial crest of 10 porcine legs. The angle created between the K-wires with an external rotation force applied was measured on a photograph and defined as the true angle. The same force was applied to the legs placed on a splint with a smartphone attached to the plantar side. The angle presented on a smartphone application was determined as the measured angle. The differences between the true and measured angles in 30° and 90° knee flexion and differences in measured angles depending on the status of the popliteus tendon were compared. In the intact knees, the mean true angles in 30° and 90° flexion were 20.5°±1.4° and 19.1°±1.3°, respectively, and the mean measured angles in 30° and 90° flexion were 21.1°±0.9° and 18.6°±1.6°, respectively. When the popliteus tendon was cut, the mean true angles in 30° and 90° flexion were 31.4°±1.1° and 38.5°±2.5°, respectively, and the mean measured angles in 30° and 90° flexion were 31.8°±1.2° and 39.2°±2.8°, respectively. The differences between the true and measured angles were not significant. The measured angle increased by more than 10° after cutting of the popliteus tendon in both 30° and 90° flexion. Using a smartphone application could be a good method of measuring knee rotation.

The effect of a knee ankle foot orthosis incorporating an active knee mechanism on gait of a person with poliomyelitis.

PubMed

Arazpour, Mokhtar; Chitsazan, Ahmad; Bani, Monireh Ahmadi; Rouhi, Gholamreza; Ghomshe, Farhad Tabatabai; Hutchins, Stephen W

2013-10-01

The aim of this case study was to identify the effect of a powered stance control knee ankle foot orthosis on the kinematics and temporospatial parameters of walking by a person with poliomyelitis when compared to a knee ankle foot orthosis. A knee ankle foot orthosis was initially manufactured by incorporating drop lock knee joints and custom molded ankle foot orthoses and fitted to a person with poliomyelitis. The orthosis was then adapted by adding electrically activated powered knee joints to provide knee extension torque during stance and also flexion torque in swing phase. Lower limb kinematic and kinetic data plus data for temporospatial parameters were acquired from three test walks using each orthosis. Walking speed, step length, and vertical and horizontal displacement of the pelvis decreased when walking with the powered stance control knee ankle foot orthosis compared to the knee ankle foot orthosis. When using the powered stance control knee ankle foot orthosis, the knee flexion achieved during swing and also the overall pattern of walking more closely matched that of normal human walking. The reduced walking speed may have caused the smaller compensatory motions detected when the powered stance control knee ankle foot orthosis was used. The new powered SCKAFO facilitated controlled knee flexion and extension during ambulation for a volunteer poliomyelitis person.

Impingement of the Mobile Bearing on the Lateral Wall of the Tibial Tray in Unicompartmental Knee Arthroplasty.

PubMed

Inui, Hiroshi; Taketomi, Shuji; Yamagami, Ryota; Sanada, Takaki; Shirakawa, Nobuyuki; Tanaka, Sakae

2016-07-01

Tilting of the mobile bearing relative to the tibial tray in the flexion position may result from the implantation of femoral components more laterally relative to tibial components during unicompartmental knee arthroplasty (UKA) using the Oxford Knee. The purpose of the present study was to compare femoral component positions after UKA using the phase 3 device and a novel device. We further evaluated the placement of the femoral components with the new device in the flexion position to determine the association with short-term prognosis. The location of femoral and tibial components in the flexion position of 38 knees implanted using the phase 3 device and 49 knees using a novel device was assessed at 1 year postoperatively using radiography of the proximal tibia and distal femur in the flexion position. The femoral component was implanted more laterally using the new device than using the phase 3 device in the flexion position (P = .012), which caused the impingement of the mobile bearing against the lateral wall of the tibial tray. After UKA using the new device, 10% of patients exhibited the tilting phenomenon of the mobile bearing because of the lateral implantation of the femoral implant. To prevent implantation of the femoral component too laterally using the new device during UKA, knee surgeons should set the drill guide more medially such that the center of the drill is aligned with the middle of the medial femoral condyle. Copyright © 2016 Elsevier Inc. All rights reserved.

The effect of tibio-femoral traction mobilization on passive knee flexion motion impairment and pain: a case series

PubMed Central

Maher, Sara; Creighton, Doug; Kondratek, Melodie; Krauss, John; Qu, Xianggui

2010-01-01

The purpose of this case series was to explore the effects of tibio-femoral (TF) manual traction on pain and passive range of motion (PROM) in individuals with unilateral motion impairment and pain in knee flexion. Thirteen participants volunteered for the study. All participants received 6 minutes of TF traction mobilization applied at end-range passive knee flexion. PROM measurements were taken before the intervention and after 2, 4, and 6 minutes of TF joint traction. Pain was measured using a visual analog scale with the TF joint at rest, at end-range passive knee flexion, during the application of joint traction, and immediately post-treatment. There were significant differences in PROM after 2 and 4 minutes of traction, with no significance noted after 4 minutes. A significant change in knee flexion of 25.9°, which exceeded the MDC95, was found when comparing PROM measurements pre- to final intervention. While pain did not change significantly over time, pain levels did change significantly during each treatment session. Pain significantly increased when the participant’s knee was passively flexed to end range; it was reduced, although not significantly, during traction mobilization; and it significantly decreased following traction. This case series supports TF joint traction as a means of stretching shortened articular and periarticular tissues without increasing reported levels of pain during or after treatment. In addition, this is the first study documenting the temporal aspects of treatment effectiveness in motion restoration. PMID:21655421

A Novel, Nonoperative Treatment Demonstrates Success for Stiff Total Knee Arthroplasty after Failure of Conventional Therapy.

PubMed

Chughtai, Morad; Mont, Michael A; Cherian, Chris; Cherian, Jeffrey Jai; Elmallah, Randa D K; Naziri, Qais; Harwin, Steven F; Bhave, Anil

2016-04-01

Certain patients continue to suffer from knee stiffness following total knee arthroplasty (TKA) despite undergoing conventional therapies. Astym therapy to these patients may offer an effective, safe, nonoperative treatment. This study evaluates the effects of Astym therapy upon (1) range of motion and (2) subjective functional improvements in post-TKA patients who suffered from stiffness recalcitrant to other nonoperative interventions. Twenty-three post-TKA patients (29 knees) who had recalcitrant knee stiffness were included in this study. Pre- and post-Astym improvements in range of motion and Knee Society scores were compared. We analyzed knees based on the presence of flexion deficit or contracture. Further stratification was made into knees that received Astym therapy before and after a 3-month period of standard rehabilitation. Differences in range of motion from pre- to post-Astym were evaluated by measuring (1) degree of flexion deficit or contracture and (2) total arc of passive motion. Improvements in subjective functional status were determined by evaluating Knee Society scores pre- and post-Astym therapy. A two-tailed Student t-test was used to compare weighted mean differences from pre- to post-Astym for the above parameters. The mean flexion deficit improved significantly (p < 0.001) in all patients after Astym therapy. The mean flexion contracture improved significantly in (p = 0.001) in 91% of patients after Astym therapy. Knees with flexion deficits or contractures both improved in total arc of motion when compared with pretherapy. Overall, patients who underwent treatment with Astym therapy reported significant mean improvements in both Knee Society objective (80 vs. 57 points; p < 0.0001) and functional scores (80 vs. 54 points; p = 0.0003) when compared with their pretherapy objective and functional scores. No harms were reported. Astym therapy is a novel, nonoperative treatment that may be an effective treatment option for post-TKA patients suffering from persistent knee stiffness. Further studies are needed to validate this intervention as a part of cost-effective, standard treatment after TKA. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Knee flexion deformity from poliomyelitis treated by supracondylar femoral extension osteotomy.

PubMed

de Moraes Barros Fucs, Patricia M; Svartman, Celso; de Assumpção, Rodrigo Montezuma César

2005-12-01

Between April 1979 and August 1993, we treated 39 patients (49 knees) with knee flexion deformity after Poliomyelitis. All were subjected to fractional hamstring lengthening and supracondylar femoral extension osteotomy in the same surgical procedure. The goal was to correct the deformity and fit the lower extremities in long braces to improve or promote gait. Patients' mean age was 19.5 (6.5-39) years and the mean knee flexion deformity was 65 degrees (24-158 degrees). The mean follow-up was 15.5 (11.5-25) years. Postoperatively, 22 knees had full extension, in 26 there was an extension lag between -1 and -10 degrees and in one a lag greater than 10 degrees. There were no neurovascular complications and all patients were fitted with long leg braces. Surgical planning is important, especially in severe deformities, where shortening of the femur is necessary to facilitate the osteotomy and relax the neurovascular structures.

Does high flexion after total knee replacement really improve our patients' quality of life at a short-term follow-up? : a comparative case-control study with hyperflex PFC Sigma versus a Triathlon knee series.

PubMed

Mencière, Maxime L; Epinette, Jean-Alain; Gabrion, Antoine; Arnalsteen, Damien; Mertl, Patrice

2014-10-01

A full range of motion after total knee arthroplasty has become more and more requested by our patients, leading to novel designs of knee implants, the so-called "hyperflex" knees. The aim of the present study was to confirm whether or not hyperflexion of operated knees really improves the patients' quality of life. A retrospective comparative case-control study has been carried out to compare clinical results shown in two types of knee prosthesis, from two homogeneous paired groups of patients including 45 cases of a "hyperflex" model (RP-F), while the control group consisted of 43 cases of a "regular design" model (Triathlon) in terms of expected postoperative flexion. The hyperflex group demonstrated significant higher mean values of passive flexion at 119.9° in the RP-F group versus 111.1° in the Triathlon group. However, global results in the "regular" control group were significantly better than the "hyperflex" study group, in both IKS knee and functional scores at 84.4 points (RP-F) vs. 89.8 points (Triathlon), and 84.6 points (RP-F) vs. 89.5 points (Triathlon), respectively. Moreover, the self-administered KOOS questionnaire was significantly in favor of the control group, with 73.5 points in RP-F knees versus 86.0 points for Triathlon knees at global KOOS postoperative scores. The quality of life of operated patients after TKA obviously would be considered as the main priority, which was better obtained by a "regular design" in our study. Hence "high flexion" cannot be considered as an absolute target when choosing a model for total knee arthroplasty.

Knee and Hip Joint Kinematics Predict Quadriceps and Hamstrings Neuromuscular Activation Patterns in Drop Jump Landings

PubMed Central

Malfait, Bart; Dingenen, Bart; Smeets, Annemie; Staes, Filip; Pataky, Todd; Robinson, Mark A.; Vanrenterghem, Jos; Verschueren, Sabine

2016-01-01

Purpose The purpose was to assess if variation in sagittal plane landing kinematics is associated with variation in neuromuscular activation patterns of the quadriceps-hamstrings muscle groups during drop vertical jumps (DVJ). Methods Fifty female athletes performed three DVJ. The relationship between peak knee and hip flexion angles and the amplitude of four EMG vectors was investigated with trajectory-level canonical correlation analyses over the entire time period of the landing phase. EMG vectors consisted of the {vastus medialis(VM),vastus lateralis(VL)}, {vastus medialis(VM),hamstring medialis(HM)}, {hamstring medialis(HM),hamstring lateralis(HL)} and the {vastus lateralis(VL),hamstring lateralis(HL)}. To estimate the contribution of each individual muscle, linear regressions were also conducted using one-dimensional statistical parametric mapping. Results The peak knee flexion angle was significantly positively associated with the amplitudes of the {VM,HM} and {HM,HL} during the preparatory and initial contact phase and with the {VL,HL} vector during the peak loading phase (p<0.05). Small peak knee flexion angles were significantly associated with higher HM amplitudes during the preparatory and initial contact phase (p<0.001). The amplitudes of the {VM,VL} and {VL,HL} were significantly positively associated with the peak hip flexion angle during the peak loading phase (p<0.05). Small peak hip flexion angles were significantly associated with higher VL amplitudes during the peak loading phase (p = 0.001). Higher external knee abduction and flexion moments were found in participants landing with less flexed knee and hip joints (p<0.001). Conclusion This study demonstrated clear associations between neuromuscular activation patterns and landing kinematics in the sagittal plane during specific parts of the landing. These findings have indicated that an erect landing pattern, characterized by less hip and knee flexion, was significantly associated with an increased medial and posterior neuromuscular activation (dominant hamstrings medialis activity) during the preparatory and initial contact phase and an increased lateral neuromuscular activation (dominant vastus lateralis activity) during the peak loading phase. PMID:27101130

Effect of repair of radial tears at the root of the posterior horn of the medial meniscus with the pullout suture technique: a biomechanical study using porcine knees.

PubMed

Seo, Jeong-Hee; Li, Guoan; Shetty, Gautam M; Kim, Ji-Hoon; Bae, Ji-Hoon; Jo, Myoung-Lae; Kim, Jung-Sung; Lee, Sung-Jae; Nha, Kyung-Wook

2009-11-01

Our purpose was to evaluate the result of radial tears at the root of the posterior horn of the medial meniscus (PHMM) in terms of tibiofemoral contact mechanics and the effectiveness of pullout sutures for such tears. Eleven mature pig knees each underwent 15 different testing conditions with an intact, simulated (incised) radial tear at the root of the PHMM and placement of pullout sutures in the radial tears of the medial meniscus at 5 different angles of flexion (0 degrees, 15 degrees, 30 degrees, 60 degrees, and 90 degrees ) under a 1,500-N axial load. A K-Scan pressure sensor (Tekscan, Boston, MA) was used to measure medial tibiofemoral contact area and peak tibiofemoral contact pressure. Data were analyzed to assess the difference in medial contact area and tibiofemoral peak contact pressure among the 3 meniscal conditions at various degrees of knee flexion. The mean contact area was significantly lower, and the peak tibiofemoral contact pressure was significantly high in knees with simulated radial tears at all angles of knee flexion compared with knees with intact menisci (P < .0001). The peak tibiofemoral contact pressure after the pullout suture technique was significantly high at 0 degrees and 15 degrees of flexion (P < .0001) compared with intact knee specimens. Failure of sutures occurred in 45% of the specimens at 0 degrees of flexion. Radial tears at the root of the PHMM in a porcine model significantly increased medial tibiofemoral contact pressure and decreased contact area. Although repair of tears of the PHMM with the pullout suture technique aids in significantly reducing tibiofemoral peak contact pressure between 30 degrees and 90 degrees , it remains significantly high at 0 degrees and 15 degrees of flexion. Pullout sutures for radial tears at the root of the PHMM may lead to an increase in peak medial tibiofemoral contact pressure and may be prone to mechanical failure, especially during the stance (loading) phase of gait (mean, 15 degrees of flexion).

Torsion and bending imposed on a new anterior cruciate ligament prosthesis during knee flexion: an evaluation method.

PubMed

Gely, P; Drouin, G; Thiry, P S; Tremblay, G R

1984-11-01

A new composite prosthesis was recently proposed for the anterior cruciate ligament. It is implanted in the femur and the tibia through two anchoring channels. Its intra-articular portion, composed of a fiber mesh sheath wrapped around a silicone rubber cylindrical core, reproduces satisfactorily the ligament response in tension. However, the prosthesis does not only undergo elongation. In addition, it is submitted to torsion in its intra-articular portion and bending at its ends. This paper presents a new method to evaluate these two types of deformations throughout a knee flexion by means of a geometric model of the implanted prosthesis. Input data originate from two sources: (i) a three-dimensional anatomic topology of the knee joint in full extension, providing the localization of the prosthesis anchoring channels, and ii) a kinematic model of the knee describing the motion of these anchoring channels during a physiological flexion of the knee joint. The evaluation method is independent of the way input data are obtained. This method, applied to a right cadaveric knee, shows that the orientation of the anchoring channels has a large effect on the extent of torsion and bending applied to the implanted prosthesis throughout a knee flexion, especially on the femoral side. The study suggests also the best choice for the anchoring channel axes orientation.

The Effects of Injury Prevention Programs on the Biomechanics of Landing Tasks: A Systematic Review With Meta-analysis.

PubMed

Lopes, Thiago Jambo Alves; Simic, Milena; Myer, Gregory D; Ford, Kevin R; Hewett, Timothy E; Pappas, Evangelos

2018-05-01

Anterior cruciate ligament (ACL) tear is a common injury in sports and often occurs during landing from a jump. To synthesize the evidence on the effects of injury prevention programs (IPPs) on landing biomechanics as they relate to the ligament, quadriceps, trunk, and leg dominance theories associated with ACL injury risk. Meta-analysis. Six electronic databases were searched for studies that investigated the effect of IPPs on landing task biomechanics. Prospective studies that reported landing biomechanics at baseline and post-IPP were included. Results from trunk, hip, and knee kinematics and kinetics related to the ACL injury theories were extracted, and meta-analyses were performed when possible. The criteria were met by 28 studies with a total of 466 participants. Most studies evaluated young females, bilateral landing tasks, and recreational athletes, while most variables were related to the ligament and quadriceps dominance theories. An important predictor of ACL injury, peak knee abduction moment, decreased ( P = .01) after the IPPs while other variables related to the ligament dominance theory did not change. Regarding the quadriceps dominance theory, after the IPPs, angles of hip flexion at initial contact ( P = .009), peak hip flexion ( P = .002), and peak knee flexion ( P = .007) increased, while knee flexion at initial contact did not change ( P = .18). Moreover, peak knee flexion moment decreased ( P = .005) and peak vertical ground-reaction force did not change ( P = .10). The exercises used in IPPs might have the potential to improve landing task biomechanics related to the quadriceps dominance theory, especially increasing peak knee and hip flexion angles. Importantly, peak knee abduction moment decreased, which indicates that IPPs influence a desired movement strategy to help athletes overcome dangerous ligament dominance loads arising from lack of frontal plane control during dynamic tasks. The lack of findings for some biomechanical variables suggests that future IPPs may be enhanced by targeting participants' baseline profile deficits, highlighting the need to deliver an individualized and task-specific IPP.

Instruction of jump-landing technique using videotape feedback: altering lower extremity motion patterns.

PubMed

Oñate, James A; Guskiewicz, Kevin M; Marshall, Stephen W; Giuliani, Carol; Yu, Bing; Garrett, William E

2005-06-01

Anterior cruciate ligament injury prevention programs have used videotapes of jump-landing technique as a key instructional component to improve landing performance. All videotape feedback model groups will increase knee flexion angles at initial contact and overall knee flexion motion and decrease peak vertical ground reaction forces and peak proximal anterior tibial shear forces to a greater extent than will a nonfeedback group. The secondary hypothesis is that the videotape feedback using the combination of the expert and self models will create the greatest change in each variable. Controlled laboratory study. Knee kinematics and kinetics of college-aged recreational athletes randomly placed in 3 different videotape feedback model groups (expert only, self only, combination of expert and self) and a nonfeedback group were collected while participants performed a basketball jump-landing task on 3 testing occasions. All feedback groups significantly increased knee angular displacement flexion angles [F(6,70) = 8.03, P = .001] and decreased peak vertical ground reaction forces [F(6,78) = 2.68, P = .021] during performance and retention tests. The self and combination groups significantly increased knee angular displacement flexion angles more than the control group did; the expert model group did not change significantly more than the control group did. All feedback groups and the nonfeedback group significantly reduced peak vertical forces across performance and retention tests. There were no statistically significant changes in knee flexion angle at initial ground contact (P = .111) and peak proximal anterior tibial shear forces (P = .509) for both testing sessions for each group. The use of self or combination videotape feedback is most useful for increasing knee angular displacement flexion angles and reducing peak vertical forces during landing. The use of self or combination modeling is more effective than is expert-only modeling for the implementation of instructional programs aimed at reducing the risk of jump-landing anterior cruciate ligament injuries.

Manipulation under anaesthesia versus low stretch device in poor range of motion after TKA.

PubMed

Witvrouw, E; Bellemans, J; Victor, J

2013-12-01

The purpose of this study was to evaluate the effectiveness of two frequently used non-operative treatment techniques for a stiff knee after total knee arthroplasty. Sixty-four patients with a stiff knee after total knee arthroplasty (TKA) were randomized into a manipulation under anaesthesia group, or a low load stretch (stretch) group. The patients were followed up for 6 weeks and were evaluated for maximum flexion and extension, range of motion (ROM), pain, stiffness and function. Both groups showed a significant increase in knee flexion in this study. Only the stretch group showed a significant increase in extension ROM. In both groups, a significant increase in Western Ontario and McMaster Universities was observed. No significant difference was observed between both groups for the flexion or extension ROM, or for any of the pain, function or stiffness scores during this study. The results of this study showed that the stretch technique had equal or superior results concerning ROM and function compared to manipulation under anaesthesia. The stretch technique achieved this without requiring the patient to undergo in-hospital treatment or anaesthesia, limiting the costs and the risks for complications. The results of this study showed that stretching is a valuable tool for treating joint contractures of the knee. Therefore, the use of this stretching technique may be an excellent first choice of treatment modality in patients with slow progress of knee flexion or persistent knee stiffness following TKA, prior to manipulation under anaesthesia or lysis of adhesions.

Patellofemoral joint contact forces during activities with high knee flexion.

PubMed

Trepczynski, Adam; Kutzner, Ines; Kornaropoulos, Evgenios; Taylor, William R; Duda, Georg N; Bergmann, Georg; Heller, Markus O

2012-03-01

The patellofemoral (PF) joint plays an essential role in knee function, but little is known about the in vivo loading conditions at the joint. We hypothesized that the forces at the PF joint exceed the tibiofemoral (TF) forces during activities with high knee flexion. Motion analysis was performed in two patients with telemetric knee implants during walking, stair climbing, sit-to-stand, and squat. TF and PF forces were calculated using a musculoskeletal model, which was validated against the simultaneously measured in vivo TF forces, with mean errors of 10% and 21% for the two subjects. The in vivo peak TF forces of 2.9-3.4 bodyweight (BW) varied little across activities, while the peak PF forces showed significant variability, ranging from less than 1 BW during walking to more than 3 BW during high flexion activities, exceeding the TF forces. Together with previous in vivo measurements at the hip and knee, the PF forces determined here provide evidence that peak forces across these joints reach values of around 3 BW during high flexion activities, also suggesting that the in vivo loading conditions at the knee can only be fully understood if the forces at the TF and the PF joints are considered together. Copyright © 2011 Orthopaedic Research Society.

Maximal voluntary isokinetic knee flexion torque is associated with femoral shaft bone strength indices in knee replacement patients.

PubMed

Rantalainen, T; Valtonen, A; Sipilä, S; Pöyhönen, T; Heinonen, A

2012-03-01

It is currently unknown whether knee replacement-associated bone loss is modified by rehabilitation programs. Thus, a sample of 45 (18 men and 25 women) persons with unilateral knee replacement were recruited; age 66 years (sd 6), height 169 cm (sd 8), body mass 83 kg (sd 15), time since operation 10 months (sd 4) to explore the associations between maximal torque/power in knee extension/flexion and femoral mid-shaft bone traits (Cortical cross-sectional area (CoA, mm(2)), cortical volumetric bone mineral density (CoD, mg/mm(3)) and bone bending strength index (SSI, mm(3))). Bone traits were calculated from a single computed tomography slice from the femoral mid-shaft. Pain in the operated knee was assessed with the WOMAC questionnaire. Stepwise regression models were built for the operated leg bone traits, with knee extension and flexion torque and power, age, height, body mass, pain score and time since operation as independent variables. CoA was 2.3% (P=0.015), CoD 1.2% (P<0.001) and SSI 1.6% (P=0.235) lower in the operated compared to non-operated leg. The overall proportions of the variation explained by the regression models were 50%, 29% and 55% for CoA, CoD and SSI, respectively. Body mass explained 12% of Coa, 11% of CoD and 11% of SSI (P≤0.003). Maximal knee flexion torque explained 38% of Coa, 7% of CoD and 44% of SSI (p≤0.047). For CoD time since operation also became a significant predictor (11%, P=0.045). Knee flexion torque of the operated leg was positively associated with bone strength in the operated leg. Thus, successful rehabilitation may diminish bone loss in the operated leg. Copyright © 2011 Elsevier B.V. All rights reserved.

Hip proprioceptors preferentially modulate reflexes of the leg in human spinal cord injury

PubMed Central

Onushko, Tanya; Hyngstrom, Allison

2013-01-01

Stretch-sensitive afferent feedback from hip muscles has been shown to trigger long-lasting, multijoint reflex responses in people with chronic spinal cord injury (SCI). These reflexes could have important implications for control of leg movements during functional activities, such as walking. Because the control of leg movement relies on reflex regulation at all joints of the limb, we sought to determine whether stretch of hip muscles modulates reflex activity at the knee and ankle and, conversely, whether knee and ankle stretch afferents affect hip-triggered reflexes. A custom-built servomotor apparatus was used to stretch the hip muscles in nine chronic SCI subjects by oscillating the legs about the hip joint bilaterally from 10° of extension to 40° flexion. To test whether stretch-related feedback from the knee or ankle would be affected by hip movement, patellar tendon percussions and Achilles tendon vibration were delivered when the hip was either extending or flexing. Surface electromyograms (EMGs) and joint torques were recorded from both legs. Patellar tendon percussions and Achilles tendon vibration both elicited reflex responses local to the knee or ankle, respectively, and did not influence reflex responses observed at the hip. Rather, the movement direction of the hip modulated the reflex responses local to the joint. The patellar tendon reflex amplitude was larger when the perturbation was delivered during hip extension compared with hip flexion. The response to Achilles vibration was modulated by hip movement, with an increased tonic component during hip flexion compared with extension. These results demonstrate that hip-mediated sensory signals modulate activity in distal muscles of the leg and appear to play a unique role in modulation of spastic muscle activity throughout the leg in SCI. PMID:23615544

[In vitro analysis of the continuous active patellofemoral kinematics of the normal and prosthetic knee].

PubMed

Jenny, J-Y; Lefèbvre, Y; Vernizeau, M; Lavaste, F; Skalli, W

2002-12-01

In vitro experiments are particularly useful for studying kinematic changes from the normal knee to experimental conditions simulating different disease states. We developed an experimental protocol allowing a kinematic analysis of the femorotibial and femoropatellar joints in the healthy knee and after implantation of a knee prosthesis, according to the central pivot during simulated active loaded movement from the standing to sitting position. An experimental device was designed to apply force to the femur of a cadaveric specimen including the femur, the patella and the tibia. The tibia was angled in the sagittal plane and the femur was free to move in space in response to the geometric movement of the knee joint, the capsuloligamentary structures, the quadriceps tendon and gravity. Variation in the length of the quadriceps tendon controlled the flexion-extension movement. The experimental setup included computer-controlled activation allowing continuous coordinated movement of the femur relative to the tibia and of the tibia relative to the ground. Standard activations simulated movement from the standing to the sitting position. Five pairs of fresh-frozen cadaver specimens including the entire femur, patella, tibia and fibula, the capsuloligamentary and intra-articular structures of the knee, the superior and inferior tibiofibular ligaments and the quadriceps tendon were studied. The quadriceps tendon was connected to the computer-guided activation device. Reflectors were fixed onto the anterior aspect of the femur, the superior tibial epiphysis and the center of the patella. Anatomic landmarks on the femur, the tibia, and the patella were identified to determine the plane of movement of each bone in the three rotation axes and the three translation directions. Three infrared cameras recorded movements of the reflectors fixed on the bony segments and, by mathematical transformation, the movement of the corresponding bony segment, displayed in time-course curves. The patella moved in continuous fashion over the femur, directly following the angle of knee flexion with a ratio of about 60%, which was constant for all knees studied and for all configurations. The patella of healthy knees and knees implanted with a unicompartmental prosthesis exhibited medial rotation during the first 30 degrees of flexion, with a movement of about of 10 degrees, then a lateral rotation of about 10 degrees to 20 degrees when the flexion reached 90 degrees; implantation of a total knee prosthesis led to a medial rotation which was continuous from 5 degrees to 15 degrees. There was a trend towards continuous abduction of about 10 degrees. The patella exhibited a continuous anterior translation of 10 to 20 mm from the tibia with increasing knee flexion, in both normal and prosthetic knees (unicompartmental prosthesis); knees implanted with a total knee prosthesis exhibited 5 to 10 mm anterior translation from 0 degrees to 50 degrees flexion, then an equivalent posterior translation for 50 degrees to 90 degrees flexion. The patella made a continuous 5 to 10 mm medial translation movement over the tibia in both normal and prosthetic (unicompartmental) knees; knees implanted with a total knee prosthesis exhibited 0 to 5 mm lateral translation starting after 50 degrees flexion. The patella also exhibited a continuous distal translation over the tibia of about 20 to 30 mm, for all configurations. The experimental set up enables a comparison of the kinetics of a normal knee with the kinetics observed after implantation of a prosthesis on the same knee. Implantation of a unicompartmental medial prosthesis, leaving the posterior cruciate ligament intact and irrespective of the status of the anterior cruciate ligament, did not, in these experimental conditions, exhibit any significant difference in the femorotibial or femoropatellar kinetics compared with the same normal knee. Implantation of a total knee prosthesis had a significant effect on the femoropatellar kinematics, compared with the same knee before implantation. The main anomalies were related to the medial-lateral rotation of the patella which exhibited an abnormal lateral rotation, possibly favorable for subluxation; these changes were directly related to femorotibial rotation after implantation of the total prosthesis and appeared to be related to the symmetry of the femoral condyles of the prosthesis model studied, perturbing the normal automatic rotation of the knee. There is thus a strong relationship between femorotibial and femoropatellar kinetics in the total knee prosthesis.

Validation of a novel smartphone accelerometer-based knee goniometer.

PubMed

Ockendon, Matthew; Gilbert, Robin E

2012-09-01

Loss of full knee extension following anterior cruciate ligament surgery has been shown to impair knee function. However, there can be significant difficulties in accurately and reproducibly measuring a fixed flexion of the knee. We studied the interobserver and the intraobserver reliabilities of a novel, smartphone accelerometer-based, knee goniometer and compared it with a long-armed conventional goniometer for the assessment of fixed flexion knee deformity. Five healthy male volunteers (age range 30 to 40 years) were studied. Measurements of knee flexion angle were made with a telescopic-armed goniometer (Lafayette Instrument, Lafayette, IN) and compared with measurements using the smartphone (iPhone 3GS, Apple Inc., Cupertino, CA) knee goniometer using a novel trigonometric technique based on tibial inclination. Bland-Altman analysis of validity and reliability including statistical analysis of correlation by Pearson's method was undertaken. The iPhone goniometer had an interobserver correlation (r) of 0.994 compared with 0.952 for the Lafayette. The intraobserver correlation was r = 0.982 for the iPhone (compared with 0.927). The datasets from the two instruments correlate closely (r = 0.947) are proportional and have mean difference of only -0.4 degrees (SD 3.86 degrees). The Lafayette goniometer had an intraobserver reliability +/- 9.6 degrees. The interobserver reliability was +/- 8.4 degrees. By comparison the iPhone had an interobserver reliability +/- 2.7 degrees and an intraobserver reliability +/- 4.6 degrees. We found the iPhone goniometer to be a reliable tool for the measurement of subtle knee flexion in the clinic setting.

Strategies utilized to transfer weight during knee flexion and extension with rotation for individuals with a total knee replacement.

PubMed

Ferris, Lauren A; Denney, Linda M; Maletsky, Lorin P

2013-02-01

Functional activities in daily life can require squatting and shifting body weight during transverse plane rotations. Stability of the knee can be challenging for people with a total knee replacement (TKR) due to reduced proprioception, nonconforming articular geometry, muscle strength, and soft tissue weakness. The objective of this study was to identify strategies utilized by individuals with TKR in double-stance transferring load during rotation and flexion. Twenty-three subjects were recruited for this study: 11 TKR subjects (age: 65 ± 6 years; BMI 27.4 ± 4.1) and 12 healthy subjects (age: 63 ± 7; BMI 24.6 ± 3.8). Each subject completed a novel crossover button push task where rotation, flexion, and extension of the knee were utilized. Each subject performed two crossover reaching tasks where the subject used the opposite hand to cross over their body and press a button next to either their shoulder (high) or knee (low), then switched hands and rotated to press the opposite button, either low or high. The two tasks related to the order they pressed the buttons while crossing over, either low-to-high (L2H) or high-to-low (H2L). Force platforms measured ground reaction forces under each foot, which were then converted to lead force ratios (LFRs) based on the total force. Knee flexion angles were also measured. No statistical differences were found in the LFRs during the H2L and L2H tasks for the different groups, although differences in the variation of the loading within subjects were noted. A significant difference was found between healthy and unaffected knee angles and a strong trend between healthy and affected subject's knee angles in both H2L and L2H tasks. Large variations in the LFR at mid-task in the TKR subjects suggested possible difficulties in maintaining positional stability during these tasks. The TKR subjects maintained more of an extended knee, which is a consistent quadriceps avoidance strategy seen by other researchers in different tasks. These outcomes suggest that individuals with a TKR utilize strategies, such as keeping an extended knee, to achieve rotary tasks during knee flexion and extension. Repeated compensatory movements could result in forces that may cause difficulty over time in the hip joints or low back. Early identification of these strategies could improve TKR success and the return to activities of daily living that involve flexion and rotation.

Instruction and jump-landing kinematics in college-aged female athletes over time.

PubMed

Etnoyer, Jena; Cortes, Nelson; Ringleb, Stacie I; Van Lunen, Bonnie L; Onate, James A

2013-01-01

Instruction can be used to alter the biomechanical movement patterns associated with anterior cruciate ligament (ACL) injuries. To determine the effects of instruction through combination (self and expert) feedback or self-feedback on lower extremity kinematics during the box-drop-jump task, running-stop-jump task, and sidestep-cutting maneuver over time in college-aged female athletes. Randomized controlled clinical trial. Laboratory. Forty-three physically active women (age = 21.47 ± 1.55 years, height = 1.65 ± 0.08 m, mass = 63.78 ± 12.00 kg) with no history of ACL or lower extremity injuries or surgery in the 2 months before the study were assigned randomly to 3 groups: self-feedback (SE), combination feedback (CB), or control (CT). Participants performed a box-drop-jump task for the pretest and then received feedback about their landing mechanics. After the intervention, they performed an immediate posttest of the box-drop-jump task and a running-stop-jump transfer test. Participants returned 1 month later for a retention test of each task and a sidestep-cutting maneuver. Kinematic data were collected with an 8-camera system sampled at 500 Hz. The independent variables were feedback group (3), test time (3), and task (3). The dependent variables were knee- and hip-flexion, knee-valgus, and hip- abduction kinematics at initial contact and at peak knee flexion. For the box-drop-jump task, knee- and hip-flexion angles at initial contact were greater at the posttest than at the retention test (P < .001). At peak knee flexion, hip flexion was greater at the posttest than at the pretest (P = .003) and was greater at the retention test than at the pretest (P = .04); knee valgus was greater at the retention test than at the pretest (P = .03) and posttest (P = .02). Peak knee flexion was greater for the CB than the SE group (P = .03) during the box-drop-jump task at posttest. For the running-stop-jump task at the posttest, the CB group had greater peak knee flexion than the SE and CT (P ≤ .05). Our results suggest that feedback involving a combination of self-feedback and expert video feedback with oral instruction effectively improved lower extremity kinematics during jump-landing tasks.

Instruction and Jump-Landing Kinematics in College-Aged Female Athletes Over Time

PubMed Central

Etnoyer, Jena; Cortes, Nelson; Ringleb, Stacie I.; Van Lunen, Bonnie L.; Onate, James A.

2013-01-01

Context: Instruction can be used to alter the biomechanical movement patterns associated with anterior cruciate ligament (ACL) injuries. Objective: To determine the effects of instruction through combination (self and expert) feedback or self-feedback on lower extremity kinematics during the box–drop-jump task, running–stop-jump task, and sidestep-cutting maneuver over time in college-aged female athletes. Design: Randomized controlled clinical trial. Setting: Laboratory. Patients or Other Participants: Forty-three physically active women (age = 21.47 ± 1.55 years, height = 1.65 ± 0.08 m, mass = 63.78 ± 12.00 kg) with no history of ACL or lower extremity injuries or surgery in the 2 months before the study were assigned randomly to 3 groups: self-feedback (SE), combination feedback (CB), or control (CT). Intervention(s): Participants performed a box–drop-jump task for the pretest and then received feedback about their landing mechanics. After the intervention, they performed an immediate posttest of the box–drop-jump task and a running–stop-jump transfer test. Participants returned 1 month later for a retention test of each task and a sidestep-cutting maneuver. Kinematic data were collected with an 8-camera system sampled at 500 Hz. Main Outcome Measure(s): The independent variables were feedback group (3), test time (3), and task (3). The dependent variables were knee- and hip-flexion, knee-valgus, and hip- abduction kinematics at initial contact and at peak knee flexion. Results: For the box–drop-jump task, knee- and hip-flexion angles at initial contact were greater at the posttest than at the retention test (P < .001). At peak knee flexion, hip flexion was greater at the posttest than at the pretest (P = .003) and was greater at the retention test than at the pretest (P = .04); knee valgus was greater at the retention test than at the pretest (P = .03) and posttest (P = .02). Peak knee flexion was greater for the CB than the SE group (P = .03) during the box–drop-jump task at posttest. For the running–stop-jump task at the posttest, the CB group had greater peak knee flexion than the SE and CT (P ≤ .05). Conclusions: Our results suggest that feedback involving a combination of self-feedback and expert video feedback with oral instruction effectively improved lower extremity kinematics during jump-landing tasks. PMID:23672380

Correlations among pelvic positions and differences in lower extremity joint angles during walking in female university students.

PubMed

Cho, Misuk

2015-06-01

[Purpose] This study aimed to identify correlations among pelvic positions and differences in lower extremity joint angles during walking in female university students. [Subjects] Thirty female university students were enrolled and their pelvic positions and differences in lower extremity joint angles were measured. [Methods] Pelvic position, pelvic torsion, and pelvic rotation were assessed using the BackMapper. In addition, motion analysis was performed to derive differences between left and right flexion, abduction, and external rotation ranges of hip joints; flexion, abduction, and external rotation ranges of knee joints; and dorsiflexion, inversion, and abduction ranges of ankle joints, according to X, Y, and Z-axes. [Results] Pelvic position was found to be positively correlated with differences between left and right hip flexion (r=0.51), hip abduction (r=0.62), knee flexion (r=0.45), knee abduction (r=0.42), and ankle inversion (r=0.38). In addition, the difference between left and right hip abduction showed a positive correlation with difference between left and right ankle dorsiflexion (r=0.64). Moreover, differences between left and right knee flexion exhibited positive correlations with differences between left and right knee abduction (r=0.41) and ankle inversion (r=0.45). [Conclusion] Bilateral pelvic tilt angles are important as they lead to bilateral differences in lower extremity joint angles during walking.

Influences of trunk flexion on mechanical energy flow in the lower extremities during gait.

PubMed

Takeda, Takuya; Anan, Masaya; Takahashi, Makoto; Ogata, Yuta; Tanimoto, Kenji; Shinkoda, Koichi

2016-05-01

[Purpose] The time-series waveforms of mechanical energy generation, absorption, and transfer through the joints indicate how movements are produced and controlled. Previous studies have used these waveforms to evaluate and describe the efficiency of human movements. The purpose of this study was to examine the influence of trunk flexion on mechanical energy flow in the lower extremities during gait. [Subjects and Methods] The subjects were 8 healthy young males (mean age, 21.8 ± 1.3 years, mean height, 170.5 ± 6.8 cm, and mean weight, 60.2 ± 6.8 kg). Subjects walked at a self-selected gait speed under 2 conditions: normal gait (condition N), and gait with trunk flexion formed with a brace to simulate spinal curvature (condition TF). The data collected from initial contact to the mid-stance of gait was analyzed. [Results] There were no significant differences between the 2 conditions in the mechanical energy flow in the knee joint and negative mechanical work in the knee joint. However, the positive mechanical work of the knee joint under condition TF was significantly less than that under condition N. [Conclusion] Trunk flexion led to knee flexion in a standing posture. Thus, a strategy of moving of center of mass upward by knee extension using less mechanical energy was selected during gait in the trunk flexed posture.

An extended OpenSim knee model for analysis of strains of connective tissues.

PubMed

Marieswaran, M; Sikidar, Arnab; Goel, Anu; Joshi, Deepak; Kalyanasundaram, Dinesh

2018-04-17

OpenSim musculoskeletal models provide an accurate simulation environment that eases limitations of in vivo and in vitro studies. In this work, a biomechanical knee model was formulated with femoral articular cartilages and menisci along with 25 connective tissue bundles representing ligaments and capsules. The strain patterns of the connective tissues in the presence of femoral articular cartilage and menisci in the OpenSim knee model was probed in a first of its kind study. The effect of knee flexion (0°-120°), knee rotation (- 40° to 30°) and knee adduction (- 15° to 15°) on the anterior cruciate, posterior cruciate, medial collateral, lateral collateral ligaments and other connective tissues were studied by passive simulation. Further, a new parameter for assessment of strain namely, the differential inter-bundle strain of the connective tissues were analyzed to provide new insights for injury kinematics. ACL, PCL, LCL and PL was observed to follow a parabolic strain pattern during flexion while MCL represented linear strain patterns. All connective tissues showed non-symmetric parabolic strain variation during rotation. During adduction, the strain variation was linear for the knee bundles except for FL, PFL and TL. Strains higher than 0.1 were observed in most of the bundles during lateral rotation followed by abduction, medial rotation and adduction. In the case of flexion, highest strains were observed in aACL and aPCL. A combination of strains at a flexion of 0° with medial rotation of 30° or a flexion of 80° with rotation of 30° are evaluated as rupture-prone kinematics.

Outcomes after arthroscopic excision of the bony prominence in the treatment of tibial spine avulsion fractures.

PubMed

Shelbourne, K Donald; Urch, Scott E; Freeman, Heather

2011-06-01

The purpose of this study was to determine the outcomes after arthroscopic excision of the bony prominence after a tibial spine avulsion fracture. This study included 7 subjects (5 female and 2 male subjects; mean age, 21.4 years). All subjects underwent preoperative rehabilitation focused on range of motion (ROM) and swelling control. Postoperative rehabilitation focused on regaining symmetric knee hyperextension and flexion. Objective examinations and subjective surveys were obtained at least 1 year after surgery. All subjects achieved normal knee extension; 6 patients achieved normal knee flexion, whereas 1 patient had nearly normal flexion. Physical examination showed a negative Lachman test with a firm end point in all patients, and the mean side-to-side difference for the KT-1000 manual maximum test (MEDmetric, San Diego, CA) was 1.3 mm. No subjects required subsequent anterior cruciate ligament reconstruction. All subjects returned to their previous level of activity without instability symptoms. At a mean of 5.7 years after surgery, the mean International Knee Documentation Committee subjective survey score was 90.6 points overall, with 4.7 out of 5 possible points for the instability question. At latest follow-up, the mean ROM was from 6° of hyperextension to 147° of flexion in the involved knee, compared with 6° of hyperextension to 148° of flexion for the noninvolved knee. The results of arthroscopic excision of the bony fragment after type II, III, or III+ tibial spine avulsion fracture are positive, with good stability, symmetric ROM, and high subjective scores. Most importantly, this procedure allows patients to regain full, symmetric hyperextension of the knee, avoiding the complications associated with extension loss. Level IV, therapeutic case series. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Kinematic Analysis of Gait Following Intra-articular Corticosteroid Injection into the Knee Joint with an Acute Exacerbation of Arthritis

PubMed Central

Mehta, Saurabh; Szturm, Tony; El-Gabalawy, Hani S.

2011-01-01

ABSTRACT Purpose: The objective of this study was to examine the effects of intra-articular corticosteroid injection (ICI) on ipsilateral knee flexion/extension, ankle dorsiflexion/plantarflexion (DF/PF), and hip abduction/adduction (abd/add) during stance phase in people with an acute exacerbation of rheumatoid arthritis (RA) of the knee joint. The study also assessed the effects of ICI on spatiotemporal parameters of gait and functional status in this group. Methods: Nine people with an exacerbation of RA of the knee were recruited. Kinematic and spatiotemporal gait parameters were obtained for each participant. Knee-related functional status was assessed using the Knee injury and Osteoarthritis Outcome Score (KOOS). Spatiotemporal gait parameters and joint angles (knee flexion, ankle DF/PF, hip abd/add) of the affected side were compared pre- and post-ICI. Results: Data for eight people were available for analysis. Median values for knee flexion and ankle PF increased significantly following ICI. Gait parameters of cadence, velocity, bilateral stride length, bilateral step length, step width, double-support percentage, and step time on the affected side also showed improvement. Pain and knee-related functional status as measured by the KOOS showed improvement. Conclusions: This study demonstrated a beneficial short-term effect of ICI on knee-joint movements, gait parameters, and knee-related functional status in people with acute exacerbation of RA of the knee. PMID:22942516

Dual-task and anticipation impact lower limb biomechanics during a single-leg cut with body borne load.

PubMed

Seymore, Kayla D; Cameron, Sarah E; Kaplan, Jonathan T; Ramsay, John W; Brown, Tyler N

2017-12-08

This study quantified how a dual cognitive task impacts lower limb biomechanics during anticipated and unanticipated single-leg cuts with body borne load. Twenty-four males performed anticipated and unanticipated cuts with and without a dual cognitive task with three load conditions: no load (∼6 kg), medium load (15% of BW), and heavy load (30% of BW). Lower limb biomechanics were submitted to a repeated measures linear mixed model to test the main and interaction effects of load, anticipation, and dual task. With body borne load, participants increased peak stance (PS) hip flexion (p = .004) and hip internal rotation (p = .001) angle, and PS hip flexion (p = .001) and internal rotation (p = .018), and knee flexion (p = .016) and abduction (p = .001) moments. With the dual task, participants decreased PS knee flexion angle (p < .001) and hip flexion moment (p = .027), and increased PS knee external rotation angle (p = .034). During the unanticipated cut, participants increased PS hip (p = .040) and knee flexion angle (p < .001), and decreased PS hip adduction (p = .001), and knee abduction (p = .005) and external rotation (p = .026) moments. Adding body borne load produces lower limb biomechanical adaptations thought to increase risk of musculoskeletal injury, but neither anticipation nor dual task exaggerated those biomechanical adaptations. With a dual task, participants adopted biomechanics known to increase injury risk; whereas, participants used lower limb biomechanics thought to decrease injury risk during unanticipated cuts. Copyright © 2017 Elsevier Ltd. All rights reserved.

Intrarater reliability of measuring the patella position by ultrasonography in weight-bearing condition.

PubMed

Chen, Chia Lin; Lo, Chu Ling; Huang, Kai Chu; Huang, Chen Fu

2017-10-01

[Purpose] The aim of this study was to determine the intrarater reliability of using ultrasonography as a measurement tool to assess the patella position in a weight-bearing condition. [Subjects and Methods] Ten healthy adults participated in this study. Ultrasonography was used to assess the patella position during step down with the loading knee in flexion (0° and 20°). The distance between the patella and lateral condyle was measured to represent the patella position on the condylar groove. Two measurements were obtained on the first day and the day after 1 week by the same investigator. [Results] Excellent intrarater reliability, ranging from 0.83 to 0.93, was shown in both conditions. Standard errors of the measurements were 0.5 mm in the straight knee and 0.7 mm in the knee flexion at 20°. Minimal differences in knee flexion at 0° and knee flexion at 20° were 1.5 mm and 1.9 mm, respectively. [Conclusion] Ultrasonography is a reliable assessment tool for evaluating the positional changes of the patella in weight-bearing activities, and it can be easily used by practitioners in the clinical setting.

The risk of manipulation under anesthesia due to unsatisfactory knee flexion after fast-track total knee arthroplasty.

PubMed

Wied, Christian; Thomsen, Morten G; Kallemose, Thomas; Myhrmann, Lis; Jensen, Lotte S; Husted, Henrik; Troelsen, Anders

2015-10-01

Fast-track TKA has significantly shortened the time available for physiotherapists to optimize knee ROM before discharge. Safety aspects concerning knee stiffness and the need for manipulation in a fast-track setting need to be illuminated. The study aims were to analyze if fast-track TKA can be considered safe considering rates of knee manipulation and if there is an association between knee ROM at time of discharge and the need for later manipulation. Primary TKAs operated in 2011 at our institution were eligible for inclusion. The study group consisted of 359 TKAs. Manipulation of the knee was performed in 21 of 359 TKAs (5.8%). Seventy-one percent were discharged with a flexion ≥70° combined with an extension deficit of ≤10°. The occurrence of MUA for these patients was 4.3%. The prevalence of knee manipulation showed a statistically significant association with the achieved knee flexion at discharge (p=0.02). Median length of stay was two days. Compared with literature findings fast-track TKA surgery may be considered safe based on the acceptable rate of knee manipulations after TKA (5.8%). We suggest ROM of ≥70° flexion combined with an extension deficit of ≤10° as an "optimal-zone" for ROM at discharge. The reason for this is the low occurrence of MUA (4.3%) in relation to the large amount of TKAs it represents (71%). The indication for MUA is multifactorial and ROM at discharge serves only as an indicator of later MUA risk. Copyright © 2015 Elsevier B.V. All rights reserved.

Intra-articular collagenase injection increases range of motion in a rat knee flexion contracture model

PubMed Central

Wong, Kayleigh; Trudel, Guy; Laneuville, Odette

2018-01-01

Objectives A knee joint contracture, a loss in passive range of motion (ROM), can be caused by prolonged immobility. In a rat knee immobilization flexion contracture model, the posterior capsule was shown to contribute to an irreversible limitation in ROM, and collagen pathways were identified as differentially expressed over the development of a contracture. Collagenases purified from Clostridium histolyticum are currently prescribed to treat Dupuytren’s and Peyronie’s contractures due to their ability to degrade collagen. The potential application of collagenases to target collagen in the posterior capsule was tested in this model. Materials and methods Rats had one hind leg immobilized, developing a knee flexion contracture. After 4 weeks, the immobilization device was removed, and the rats received one 50 µL intra-articular injection of 0.6 mg/mL purified collagenase. Control rats were injected with only the buffer. After 2 weeks of spontaneous remobilization following the injections, ROM was measured with a rat knee arthrometer, and histological sections were immunostained with antibodies against rat collagen types I and III. Results/conclusion Compared with buffer-injected control knees, collagenase-treated knees showed increased ROM in extension by 8.0°±3.8° (p-value <0.05). Immunohistochemical analysis revealed an increase in collagen type III staining (p<0.01) in the posterior capsule of collagenase-treated knees indicating an effect on the extracellular matrix due to the collagenase. Collagen I staining was unchanged (p>0.05). The current study provides experimental evidence for the pharmacological treatment of knee flexion contractures with intra-articular collagenase injection, improving the knee ROM. PMID:29317799

Body mass index affects knee joint mechanics during gait differently with and without moderate knee osteoarthritis.

PubMed

Harding, Graeme T; Hubley-Kozey, Cheryl L; Dunbar, Michael J; Stanish, William D; Astephen Wilson, Janie L

2012-11-01

Obesity is a highly cited risk factor for knee osteoarthritis (OA), but its role in knee OA pathogenesis and progression is not as clear. Excess weight may contribute to an increased mechanical burden and altered dynamic movement and loading patterns at the knee. The objective of this study was to examine the interacting role of moderate knee OA disease presence and obesity on knee joint mechanics during gait. Gait analysis was performed on 104 asymptomatic and 140 individuals with moderate knee OA. Each subject group was divided into three body mass categories based on body mass index (BMI): healthy weight (BMI<25), overweight (25≤BMI≤30), and obese (BMI>30). Three-dimensional knee joint angles and net external knee joint moments were calculated and waveform principal component analysis (PCA) was applied to extract major patterns of variability from each. PC scores for major patterns were compared between groups using a two-factor ANOVA. Significant BMI main effects were found in the pattern of the knee adduction moment, the knee flexion moment, and the knee rotation moment during gait. Two interaction effects between moderate OA disease presence and BMI were also found that described different changes in the knee flexion moment and the knee flexion angle with increased BMI with and without knee OA. Our results suggest that increased BMI is associated with different changes in biomechanical patterns of the knee joint during gait depending on the presence of moderate knee OA. Copyright © 2012 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Body size and lower limb posture during walking in humans

PubMed Central

Hora, Martin; Soumar, Libor; Pontzer, Herman; Sládek, Vladimír

2017-01-01

We test whether locomotor posture is associated with body mass and lower limb length in humans and explore how body size and posture affect net joint moments during walking. We acquired gait data for 24 females and 25 males using a three-dimensional motion capture system and pressure-measuring insoles. We employed the general linear model and commonality analysis to assess the independent effect of body mass and lower limb length on flexion angles at the hip, knee, and ankle while controlling for sex and velocity. In addition, we used inverse dynamics to model the effect of size and posture on net joint moments. At early stance, body mass has a negative effect on knee flexion (p < 0.01), whereas lower limb length has a negative effect on hip flexion (p < 0.05). Body mass uniquely explains 15.8% of the variance in knee flexion, whereas lower limb length uniquely explains 5.4% of the variance in hip flexion. Both of the detected relationships between body size and posture are consistent with the moment moderating postural adjustments predicted by our model. At late stance, no significant relationship between body size and posture was detected. Humans of greater body size reduce the flexion of the hip and knee at early stance, which results in the moderation of net moments at these joints. PMID:28192522

Biomechanical Evaluation of Knee Joint Laxities and Graft Forces After Anterior Cruciate Ligament Reconstruction by Anteromedial Portal, Outside-In, and Transtibial Techniques

PubMed Central

Sim, Jae Ang; Gadikota, Hemanth R.; Li, Jing-Sheng; Li, Guoan; Gill, Thomas J.

2013-01-01

Background Recently, anatomic anterior cruciate ligament (ACL) reconstruction is emphasized to improve joint laxity and to potentially avert initiation of cartilage degeneration. There is a paucity of information on the efficacy of ACL reconstructions by currently practiced tunnel creation techniques in restoring normal joint laxity. Study Design Controlled laboratory study. Hypothesis Anterior cruciate ligament reconstruction by the anteromedial (AM) portal technique, outside-in (OI) technique, and modified transtibial (TT) technique can equally restore the normal knee joint laxity and ACL forces. Methods Eight fresh-frozen human cadaveric knee specimens were tested using a robotic testing system under an anterior tibial load (134 N) at 0°, 30°, 60°, and 90° of flexion and combined torques (10-N·m valgus and 5-N·m internal tibial torques) at 0° and 30° of flexion. Knee joint kinematics, ACL, and ACL graft forces were measured in each knee specimen under 5 different conditions (ACL-intact knee, ACL-deficient knee, ACL-reconstructed knee by AM portal technique, ACL-reconstructed knee by OI technique, and ACL-reconstructed knee by TT technique). Results Under anterior tibial load, no significant difference was observed between the 3 reconstructions in terms of restoring anterior tibial translation (P > .05). However, none of the 3 ACL reconstruction techniques could completely restore the normal anterior tibial translations (P <.05). Under combined tibial torques, both AM portal and OI techniques closely restored the normal knee anterior tibial translation (P > .05) at 0° of flexion but could not do so at 30° of flexion (P <.05). The ACL reconstruction by the TT technique was unable to restore normal anterior tibial translations at both 0° and 30° of flexion under combined tibial torques (P <.05). Forces experienced by the ACL grafts in the 3 reconstruction techniques were lower than those experienced by normal ACL under both the loading conditions. Conclusion Anterior cruciate ligament reconstructions by AM portal, OI, and modified TT techniques are biomechanically comparable with each other in restoring normal knee joint laxity and in situ ACL forces. Clinical Relevance Anterior cruciate ligament reconstructions by AM portal, OI, and modified TT techniques result in similar knee joint laxities. Technical perils and pearls should be carefully considered before choosing a tunnel creating technique. PMID:21908717

Simulation of Anterior Cruciate Ligament Deficiency in a Musculoskeletal Model with Anatomical Knees

PubMed Central

Guess, Trent M; Stylianou, Antonis

2012-01-01

Abnormal knee kinematics and meniscus injury resulting from anterior cruciate ligament (ACL) deficiency are often implicated in joint degeneration even though changes in tibio-femoral contact location after injury are small, typically only a few millimeters. Ligament reconstruction surgery does not significantly reduce the incidence of early onset osteoarthritis. Increased knowledge of knee contact mechanics would increase our understanding of the effects of ACL injury and help guide ACL reconstruction methods. Presented here is a cadaver specific computational knee model combined with a body-level musculoskeletal model from a subject of similar height and weight as the cadaver donor. The knee model was developed in the multi-body framework and includes representation of the menisci. Experimental body-level measurements provided input to the musculoskeletal model. The location of tibio-menisco-femoral contact as well as contact pressures were compared for models with an intact ACL, partial ACL transection (posterolateral bundle transection), and full ACL transection during a muscle driven forward dynamics simulation of a dual limb squat. During the squat, small changes in femur motion relative to the tibia for both partial and full ACL transection push the lateral meniscus in the posterior direction at extension. The central-anterior region of the lateral meniscus then becomes “wedged” between the tibia and femur during knee flexion. This “wedging” effect does not occur for the intact knee. Peak contact pressure and contact locations are similar for the partial tear and complete ACL transection during the deep flexion portion of the squat, particularly on the lateral side. The tibio-femoral contact location on the tibia plateau shifts slightly to the posterior and lateral direction with ACL transection. PMID:22470411

A Comparison of Two Surgical Techniques Using the Unity Knee™ Total Knee System

ClinicalTrials.gov

2018-04-24

Osteoarthritis, Knee; Rheumatoid Arthritis; Post-Traumatic Osteoarthritis of Knee; Varus Deformity, Not Elsewhere Classified, Knee; Valgus Deformity, Not Elsewhere Classified, Knee; Flexion Deformity, Knee; Fracture of Distal End of Femur; Fracture of Upper End of Tibia

The acute effect of the tongue position in the mouth on knee isokinetic test performance: a highly surprising pilot study

PubMed Central

di Vico, Rosa; Ardigò, Luca Paolo; Salernitano, Gianluca; Chamari, Karim; Padulo, Johnny

2013-01-01

Summary The tongue involvement within the isokinetic knee extension/flexion exercises has been investigated. Eighteen participants randomly underwent isokinetic testing at 90 and 180°/s with three different tongue positions: middle position (MID, thrusting on the lingual surface of incisive teeth), lying on the lower arch of the mouth (LOW) and extended up to the palatine spot (UP). Statistical analysis of the data revealed an about 30% significant increase of knee flexion peak torque in UP with respect to MID at both angular speeds. Such a difference could have had a confounding effect on results from numerous past studies using isokinetic knee flexion testing. This study alerts future researchers about standardization of tongue position and warrants further investigations on the explicative processes of this phenomenon. PMID:24596696

Novel knee joint mechanism of transfemoral prosthesis for stair ascent.

PubMed

Inoue, Koh; Wada, Takahiro; Harada, Ryuchi; Tachiwana, Shinichi

2013-06-01

The stability of a transfemoral prosthesis when walking on flat ground has been established by recent advances in knee joint mechanisms and their control methods. It is, however, difficult for users of a transfemoral prosthesis to ascend stairs. This difficulty is mainly due to insufficient generation of extension moment around the knee joint of the prosthesis to lift the body to the next step on the staircase and prevent any unexpected flexion of the knee joint in the stance phase. Only a prosthesis with an actuator has facilitated stair ascent using a step-over-step gait (1 foot is placed per step). However, its use has issues associated with the durability, cost, maintenance, and usage environment. Therefore, the purpose of this research is to develop a novel knee joint mechanism for a prosthesis that generates an extension moment around the knee joint in the stance phase during stair ascent, without the use of any actuators. The proposed mechanism is based on the knowledge that the ground reaction force increases during the stance phase when the knee flexion occurs. Stair ascent experiments with the prosthesis showed that the proposed prosthesis can realize stair ascent without any undesirable knee flexion. In addition, the prosthesis is able to generate a positive knee joint moment power in the stance phase even without any power source.

[Effect of posterior condylar offset on knee flexion after high-flex posterior-stabilized total knee arthroplasty].

PubMed

Zhang, Yu; Liu, Jun; Tian, Meng-qiang; Cheng, Yu; Tian, Zheng-wei; Sun, Zhen-hui; Ma, Xin-long

2010-05-15

To determine the effect of the posterior condylar offset (PCO) on intra- and post-operative knee flexion after total knee arthroplasty (TKA) using a high-flex posterior-stabilized (PS) fixed-bearing prosthesis and to discuss it's importance in femoral prosthesis design. The clinical and radiographic materials of 100 consecutive patients (100 knees) were prospectively studied, including 50 men and 50 women, who had undergone primary NexGen LPS-Flex TKAs for end-stage osteoarthritis. All operations were performed by a single surgeon using the same operative technique between March 2005 and October 2006. Pearson's regression analysis was used to assess the relationship between the difference in the pre- and post-operative PCO on true lateral radiographs and the change in knee range of flexion (ROF) under non-weight-bearing conditions. The decrease of the corrected PCO was (3.4 ± 3.3) mm compared with the preoperative value, the restoration of PCO was better in male than female [female (-5.4 ± 3.1) mm vs. male (-1.5 ± 2.0) mm, P < 0.05]. The difference in the corrected PCO after PS TKA demonstrated significantly correlated with the change in 2 years postoperative ROF in male and female, respectively (P < 0.05). While no statistically correlation was observed in the overall group (P > 0.05). Intraoperatively, the difference in the corrected PCO was significantly correlated with the change in ROF in male, female, and the overall group, respectively (P < 0.05). Restoration of PCO plays an important role in the optimization of knee flexion after high-flex PS TKA. Femoral components based on Caucasian anatomic characteristics could not match the native anatomy of distal femurs of Chinese population especially female Chinese. Rotated resection of distal femur with anterior referencing technique usually leads to a decreased PCO and therefore reduces maximal obtainable flexion. Sexual dimorphism in humans and anatomic variations in various ethnic groups should be seriously considered in total knee prosthesis design.

NOT ALL SINGLE LEG SQUATS ARE EQUAL: A BIOMECHANICAL COMPARISON OF THREE VARIATIONS.

PubMed

Khuu, Anne; Foch, Eric; Lewis, Cara L

2016-04-01

The single leg squat (SLS) is a functional task used by practitioners to evaluate and treat multiple pathologies of the lower extremity. Variations of the SLS may have different neuromuscular and biomechanical demands. The effect of altering the non-stance leg position during the SLS on trunk, pelvic, and lower extremity mechanics has not been reported. The purpose of this study was to compare trunk, pelvic, hip, knee, and ankle kinematics and hip, knee, and ankle kinetics of three variations of the SLS using different non-stance leg positions: SLS-Front, SLS-Middle, and SLS-Back. Sixteen healthy women performed the three SLS tasks while data were collected using a motion capture system and force plates. Joint mechanics in the sagittal, frontal, and transverse planes were compared for the SLS tasks using a separate repeated-measures analysis of variance (ANOVA) for each variable at two analysis points: peak knee flexion (PKF) and 60 ° of knee flexion (60KF). Different non-stance leg positions during the SLS resulted in distinct movement patterns and moments at the trunk, pelvis, and lower extremity. At PKF, SLS-Back exhibited the greatest kinematic differences (p < 0.05) from SLS-Front and SLS-Middle with greater ipsilateral trunk flexion, pelvic anterior tilt and drop, hip flexion and adduction, and external rotation as well as less knee flexion and abduction. SLS-Back also showed the greatest kinetic differences (p < 0.05) from SLS-Front and SLS-Middle with greater hip external rotator moment and knee extensor moment as well as less hip extensor moment and knee adductor moment at PKF. At 60KF, the findings were similar except at the knee. The mechanics of the trunk, pelvis, and lower extremity during the SLS were affected by the position of the non-stance leg in healthy females. Practitioners can use these findings to distinguish between SLS variations and to select the appropriate SLS for assessment and rehabilitation. 3.

An Accurate Full-flexion Anterolateral Portal for Needle Placement in the Knee Joint With Dry Osteoarthritis.

PubMed

Hussein, Mohamed

2017-07-01

Accurate delivery of an injection into the intra-articular space of the knee is achieved in only two thirds of knees when using the standard anterolateral portal. The use of a modified full-flexion anterolateral portal provides a highly accurate, less painful, and more effective method for reproducible intra-articular injection without the need for ultrasonographic or fluoroscopic guidance in patients with dry osteoarthritis of the knee. The accuracy of needle placement was assessed in a prospective series of 140 consecutive injections in patients with symptomatic degenerative knee arthritis without clinical knee effusion. Procedural pain was determined using the Numerical Rating Scale. The accuracy rates of needle placement were confirmed with fluoroscopic imaging to document the dispersion pattern of injected contrast material. Using the standard anterolateral portal, 52 of 70 injections were confirmed to have been placed in the intra-articular space on the first attempt (accuracy rate, 74.2%). Using the modified full-flexion anterolateral portal, 68 of 70 injections were placed in the intra-articular space on the first attempt (accuracy rate, 97.1%; P = 0.000). This study revealed that using the modified full-flexion anterolateral portal for injections into the knee joint resulted in more accurate and less painful injections than those performed by the same orthopaedic surgeon using the standard anterolateral portal. In addition, the technique offered therapeutic delivery into the joint without the need for fluoroscopic confirmation. Therapeutic Level II.

Mechanical factors relate to pain in knee osteoarthritis.

PubMed

Maly, Monica R; Costigan, Patrick A; Olney, Sandra J

2008-07-01

Pain experienced by people with knee osteoarthritis is related to psychosocial factors and damage to articular tissues and/or the pain pathway itself. Mechanical factors have been speculated to trigger this pain experience; yet mechanics have not been identified as a source of pain in this population. The purpose of this study was to identify whether mechanics could explain variance in pain intensity in people with knee osteoarthritis. Data from 53 participants with physician-diagnosed knee osteoarthritis (mean age=68.5 years; standard deviation=8.6 years) were analyzed. Pain intensity was reported on the Western Ontario and McMaster Universities Osteoarthritis Index. Mechanical measures included weight-bearing varus-valgus alignment, body mass index and isokinetic quadriceps torque. Gait analysis captured the range of adduction-abduction angle, range of flexion-extension angle and external knee adduction moment during level walking. Pain intensity was significantly related to the dynamic range of flexion-extension during gait and body mass index. A total of 29% of the variance in pain intensity was explained by mechanical variables. The range of flexion-extension explained 18% of variance in pain intensity. Body mass index added 11% to the model. The knee adduction moment was unrelated to pain intensity. The findings support that mechanical factors are related to knee osteoarthritis pain. Because limitations in flexion-extension range of motion and body size are modifiable factors, future research could examine whether interventions targeting these mechanics would facilitate pain management.

Comparison of 2 surgical techniques for reconstructing posterolateral corner of the knee: a cadaveric study evaluated by navigation system.

PubMed

Ho, Eric Po-Yan; Lam, Mak-Ham; Chung, Mandy Man-Ling; Fong, Daniel Tik-Pui; Law, Billy Kan-Yip; Yung, Patrick Shu-Hang; Chan, Wood-Yee; Chan, Kai-Ming

2011-01-01

This study aimed to evaluate the immediate effect on knee kinematics by 2 different techniques of posterolateral corner (PLC) reconstruction. Five intact formalin-preserved cadaveric knees were used in this study. A navigation system was used to measure knee kinematics (posterior translation, varus angulation, and external rotation) after application of a constant force and torque to the tibia. Four different conditions of the knee were evaluated during the biomechanical test: intact knee and PLC-sectioned knee and PLC-reconstructed knee by the double-femoral tunnel technique and single-femoral tunnel technique. Sectioning of the PLC structures resulted in significant increases in external rotation at 30° of flexion from 11.2° (SD, 2.6) to 24.6° (SD, 6.2), posterior translation at 30° of flexion from 3.4 mm (SD, 1.5) to 7.4 mm (SD, 3.8), and varus angulation at 0° of flexion from 2.3° (SD, 2.1) to 7.9° (SD, 5.1). Both reconstruction techniques significantly restored the varus stability. The external rotation and posterior translation at 30° of flexion after reconstruction with the double-femoral tunnel technique were 10.2° (SD, 1.3) and 3.4° (SD, 2.7), respectively, which were significantly better than those of the single-femoral tunnel technique. Both techniques of reconstruction showed improved stability compared with PLC-sectioned knees. The double-femoral tunnel technique in PLC reconstruction showed better rotational stability and resistance to posterior translation than the single-femoral tunnel technique without compromising varus stability. PLC reconstruction by a double-femoral tunnel technique achieves better rotational control and resistance to posterior translation. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Reliability and validity of the Performance Recorder 1 for measuring isometric knee flexor and extensor strength.

PubMed

Neil, Sarah E; Myring, Alec; Peeters, Mon Jef; Pirie, Ian; Jacobs, Rachel; Hunt, Michael A; Garland, S Jayne; Campbell, Kristin L

2013-11-01

Muscular strength is a key parameter of rehabilitation programs and a strong predictor of functional capacity. Traditional methods to measure strength, such as manual muscle testing (MMT) and hand-held dynamometry (HHD), are limited by the strength and experience of the tester. The Performance Recorder 1 (PR1) is a strength assessment tool attached to resistance training equipment and may be a time- and cost-effective tool to measure strength in clinical practice that overcomes some limitations of MMT and HHD. However, reliability and validity of the PR1 have not been reported. Test-retest and inter-rater reliability was assessed using the PR1 in healthy adults (n  =  15) during isometric knee flexion and extension. Criterion-related validity was assessed through comparison of values obtained from the PR1 and Biodex® isokinetic dynamometer. Test-retest reliability was excellent for peak knee flexion (intra-class correlation coefficient [ICC] of 0.96, 95% CI: 0.85, 0.99) and knee extension (ICC  =  0.96, 95% CI: 0.87, 0.99). Inter-rater reliability was also excellent for peak knee flexion (ICC  =  0.95, 95% CI: 0.85, 0.99) and peak knee extension (ICC  =  0.97, 95% CI: 0.91, 0.99). Validity was moderate for peak knee flexion (ICC  =  0.75, 95% CI: 0.38, 0.92) but poor for peak knee extension (ICC  =  0.37, 95% CI: 0, 0.73). The PR1 provides a reliable measure of isometric knee flexor and extensor strength in healthy adults that could be used in the clinical setting, but absolute values may not be comparable to strength assessment by gold-standard measures.

Brief followup report: Does high-flexion total knee arthroplasty allow deep flexion safely in Asian patients?

PubMed

Han, Hyuk-Soo; Kang, Seung-Baik

2013-05-01

The long-term survivorship of TKA in Asian countries is comparable to that in Western countries. High-flexion TKA designs were introduced to improve flexion after TKA. However, several studies suggest high-flexion designs are at greater risk of femoral component loosening compared with conventional TKA designs. We previously reported a revision rate of 21% at 11 to 45 months; this report is intended as a followup to that study. Do implant survival and function decrease with time and do high-flexion activities increase the risk of premature failure? We prospectively followed 72 Nexgen LPS-flex fixed TKAs in 47 patients implanted by a single surgeon between March 2003 and September 2004. We determined the probability of survival using revision as an end point and compared survival between those who could and those who could not perform high-flexion activities. Minimum followup was 0.9 years (median, 6.5 years; range, 0.9-8.6 years). Twenty-five patients (33 knees) underwent revision for aseptic loosening of the femoral component at a mean of 4 years (range, 1-8 years). The probability of revision-free survival for aseptic loosening was 67% and 52% at 5 and 8 years, respectively. Eight-year cumulative survivorship was lower in patients capable of squatting, kneeling, or sitting crosslegged (31% compared with 78%). There were no differences in the pre- and postoperative mean Hospital for Special Surgery scores and maximum knee flexion degrees whether or not high-flexion activities could be achieved. Overall midterm high-flexion TKA survival in our Asian cohort was lower than that of conventional and other high-flexion designs. This unusually high rate of femoral component loosening was associated with postoperative high-flexion activities.

Knee flexion with quadriceps cocontraction: A new therapeutic exercise for the early stage of ACL rehabilitation.

PubMed

Biscarini, Andrea; Contemori, Samuele; Busti, Daniele; Botti, Fabio M; Pettorossi, Vito E

2016-12-08

Quadriceps strengthening exercises designed for the early phase of anterior cruciate ligament (ACL) rehabilitation should limit the anterior tibial translation developed by quadriceps contraction near full knee extension, in order to avoid excessive strain on the healing tissue. We hypothesize that knee-flexion exercises with simultaneous voluntary contraction of quadriceps (voluntary quadriceps cocontraction) can yield considerable levels of quadriceps activation while preventing the tibia from translating forward relative to the femur. Electromyographic activity in quadriceps and hamstring muscles was measured in 20 healthy males during isometric knee-flexion exercises executed near full knee extension with maximal voluntary effort of quadriceps cocontraction and external resistance (R) ranging from 0% to 60% of the 1-repetition maximum (1RM). Biomechanical modeling was applied to derive the shear (anterior/posterior) tibiofemoral force developed in each exercise condition. Isometric knee-flexion exercises with small external resistance (R=10% 1RM) and maximal voluntary effort of quadriceps cocontraction yielded a net posterior (ACL-unloading) tibial pull (P=0.005) and levels of activation of 32%, 50%, and 45% of maximum voluntary isometric contraction, for the rectus femoris, vastus medialis, and vastus lateralis, respectively. This exercise might potentially rank as one of the most appropriate quadriceps strengthening interventions in the early phase of ACL rehabilitation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Tactile cues can change movement: An example using tape to redistribute flexion from the lumbar spine to the hips and knees during lifting.

PubMed

Pinto, Brendan L; Beaudette, Shawn M; Brown, Stephen H M

2018-05-14

Given the appropriate cues, kinematic factors associated with low back injury risk and pain, such as spine flexion, can be avoided. Recent research has demonstrated the potential for tactile sensory information to change movement. In this study an athletic strapping tape was applied bilaterally along the lumbar extensor muscles to provide continuous tactile feedback information during a repeated lifting and lowering task. The presence of the tape resulted in a statistically significant reduction in lumbar spine flexion when compared to a baseline condition in which no tape was present. This reduction was further increased with the explicit instruction to pay attention to the sensations elicited by the tape. In both cases, the reduction in lumbar spine flexion was compensated for by increases in hip and knee flexion. When the tape was then removed and participants were instructed to continue lifting as if it was still present, the reduction in lumbar flexion and increases in hip and knee flexion were retained. Thus this study provides evidence that tactile cues can provide vital feedback information that can cue human lumbar spine movement to reduce kinematic factors associated with injury risk and pain. Copyright © 2018 Elsevier B.V. All rights reserved.

Tibiofemoral joint contact area and pressure after single- and double-bundle anterior cruciate ligament reconstruction.

PubMed

Morimoto, Yusuke; Ferretti, Mario; Ekdahl, Max; Smolinski, Patrick; Fu, Freddie H

2009-01-01

The purpose of this study was to compare the tibiofemoral contact area and pressure after single-bundle (SB) and double-bundle (DB) anterior cruciate ligament (ACL) reconstruction by use of 2 femoral and 2 tibial tunnels in intact cadaveric knees. Tibiofemoral contact area and mean and maximum pressures were measured by pressure-sensitive film (Fujifilm, Valhalla, NY) inserted between the tibia and femur. The knee was subjected to a 1,000-N axial load by use of a uniaxial testing machine at 0 degrees , 15 degrees , 30 degrees , and 45 degrees of flexion. Three conditions were evaluated: (1) intact ACL, (2) SB ACL reconstruction (n = 10 knees), and (3) DB ACL reconstruction (n = 9 knees). When compared with the intact knee, DB ACL reconstruction showed no significant difference in tibiofemoral contact area and mean and maximum pressures. SB ACL reconstruction had a significantly smaller contact area on the lateral and medial tibiofemoral joints at 30 degrees and 15 degrees of flexion. SB ACL reconstruction also had significantly higher mean pressures at 15 degrees of flexion on the medial tibiofemoral joint and at 0 degrees and 15 degrees of flexion on the lateral tibiofemoral joint, as well as significantly higher maximum pressures at 15 degrees of flexion on the lateral tibiofemoral joint. SB ACL reconstruction resulted in a significantly smaller tibiofemoral contact area and higher pressures. DB ACL more closely restores the normal contact area and pressure mainly at low flexion angles. Our findings suggest that the changes in the contact area and pressures after SB ACL reconstruction may be one of the causes of osteoarthritis on long-term follow-up. DB ACL reconstruction may reduce the incidence of osteoarthritis by closely restoring contact area and pressure.

Varus-valgus stability at 90° flexion correlates with the stability at midflexion range more widely than that at 0° extension in posterior-stabilized total knee arthroplasty.

PubMed

Hino, Kazunori; Kutsuna, Tatsuhiko; Watamori, Kunihiko; Kiyomatsu, Hiroshi; Ishimaru, Yasumitsu; Takeba, Jun; Watanabe, Seiji; Shiraishi, Yoshitaka; Miura, Hiromasa

2017-10-01

Midflexion stability can potentially improve the outcome of total knee arthroplasty (TKA). The purpose of this study was to evaluate the correlation between varus-valgus stability at 0° of extension and 90° of flexion and that at the midflexion range in posterior-stabilized (PS)-TKA. Forty-three knees that underwent PS-TKA were evaluated. Manual mild passive varus-valgus stress was applied to the knees, and the postoperative maximum varus-valgus stability was measured every 10° throughout range of motion, using a navigation system. Correlations between the stability at 0°, 90° of flexion, and that at each midflexion angle were evaluated using Spearman's correlation coefficients. The stability of 0° modestly correlated with that of 10°-20°, but it did not significantly correlate with that of 30°-80°. However, the stability of 90° strongly correlated with that of 60°-80°, modestly correlated with that of 40°-50°, weakly correlated with that of 20°-30°, and did not correlate with that of 10°. The present study confirmed the importance of acquiring stability at 90° flexion to achieve midflexion stability in PS-TKA. However, initial flexion stability did not strongly correlate with the stability at either 0° or 90°. Our findings can provide useful information for understanding varus-valgus stability throughout the range of motion in PS-TKA. Attention to soft tissue balancing is necessary to stabilize a knee at the initial flexion range in PS-TKA.

Biomechanical consequences of a nonanatomic posterior medial meniscal root repair.

PubMed

LaPrade, Christopher M; Foad, Abdullah; Smith, Sean D; Turnbull, Travis Lee; Dornan, Grant J; Engebretsen, Lars; Wijdicks, Coen A; LaPrade, Robert F

2015-04-01

Posterior medial meniscal root tears have been reported to extrude with the meniscus becoming adhered posteromedially along the posterior capsule. While anatomic repair has been reported to restore tibiofemoral contact mechanics, it is unknown whether nonanatomic positioning of a meniscal root repair to a posteromedial location would restore the loading profile of the knee joint. The purpose of this study was to compare the tibiofemoral contact mechanics of a nonanatomic posterior medial meniscal tear with that of the intact knee or anatomic repair. It was hypothesized that a nonanatomic root repair would not restore the tibiofemoral contact pressures and areas to that of the intact or anatomic repair state. Controlled laboratory study. Tibiofemoral contact mechanics were recorded in 6 male human cadaveric knee specimens (average age, 45.8 years) using pressure sensors. Each knee underwent 5 testing conditions for the posterior medial meniscal root: (1) intact knee; (2) root tear; (3) anatomic transtibial pull-out repair; (4) nonanatomic transtibial pull-out repair, placed 5 mm posteromedially along the edge of the articular cartilage; and (5) root tear concomitant with an ACL tear. Knees were loaded with a 1000-N axial compressive force at 4 flexion angles (0°, 30°, 60°, 90°), and contact area, mean contact pressure, and peak contact pressure were calculated. Contact area was significantly lower after nonanatomic repair than for the intact knee at all flexion angles (mean = 44% reduction) and significantly higher for anatomic versus nonanatomic repair at all flexion angles (mean = 27% increase). At 0° and 90°, and when averaged across flexion angles, the nonanatomic repair significantly increased mean contact pressures in comparison to the intact knee or anatomic repair. When averaged across flexion angles, the peak contact pressures after nonanatomic repair were significantly higher than the intact knee but not the anatomic repair. In contrast, when averaged across all flexion angles, the anatomic repair resulted in a 17% reduction in contact area and corresponding increases in mean and peak contact pressures of 13% and 26%, respectively, compared with the intact knee. For most testing conditions, the nonanatomic repair did not restore the contact area or mean contact pressures to that of the intact knee or anatomic repair. However, the anatomic repair produced near-intact contact area and resulted in relatively minimal increases in mean and peak contact pressures compared with the intact knee. Results emphasize the importance of ensuring an anatomic posterior medial meniscal root repair by releasing the extruded menisci from adhesions and the posteromedial capsule. Similar caution toward preventing displacement of the meniscal root repair construct should be emphasized. © 2015 The Author(s).

Biomechanical comparison of two surgical techniques for press-fit reconstruction of the posterolateral complex of the knee.

PubMed

Panzica, Martin; Janzik, Janne; Bobrowitsch, Evgenij; Krettek, Christian; Hawi, Nael; Hurschler, Christof; Jagodzinski, Michael

2015-11-01

To date, various surgical techniques to treat posterolateral knee instability have been described. Recent studies recommended an anatomical and isometric reconstruction of the posterolateral corner addressing the key structures, such as lateral collateral ligament (LCL), popliteus tendon (POP) and popliteofibular ligament (PFL). Two clinical established autologous respective local reconstruction methods of the posterolateral complex were tested for knot-bone cylinder press-fit fixation to assess efficacy of each reconstruction technique in comparison to the intact knee. The knot-bone cylinder press-fit fixation for both anatomic and isometric reconstruction techniques of the posterolateral complex shows equal biomechanical stability as the intact posterolateral knee structures. This was a controlled laboratory study. Two surgical techniques (Larson: fibula-based semitendinosus autograft for LCL and PFL reconstruction/Kawano: biceps femoris and iliotibial tract autograft for LCL, PFL and POP reconstruction) with press-fit fixation were used for restoration of posterolateral knee stability. Seven cadaveric knees (66 ± 3.4 years) were tested under three conditions: intact knee, sectioned state and reconstructed knee for each surgical technique. Biomechanical stress tests were performed for every state at 30° and 90° knee flexion for anterior-posterior translation (60 N), internal-external and varus-valgus rotation (5 Nm) at 0°, 30° and 90° using a kinemator (Kuka robot). At 30° and 90° knee flexion, no significant differences between the four knee states were registered for anterior-posterior translation loading. Internal-external and varus-valgus rotational loading showed significantly higher instability for the sectioned state than for the intact or reconstructed posterolateral structures (p < 0.05). There were no significant differences between the intact and reconstructed knee states for internal-external rotation, varus-valgus rotation and anterior-posterior translation at any flexion angles (p > 0.05). Comparing both reconstruction techniques, significant higher varus-/valgus stability was registered for the fibula-based Larson technique at 90° knee flexion (p < 0.05). Both PLC reconstructions showed equal biomechanical stability as the intact posterolateral knee structures when using knot-bone cylinder press-fit fixation. We registered restoration of the rotational and varus-valgus stability with both surgical techniques. The anterior-posterior translational stability was not influenced significantly. The Larson technique showed significant higher varus/valgus stability in 90° flexion. The latter is easier to perform and takes half the preparation time, but needs grafting of the semitendinosus tendon. The Kawano reconstruction technique is an interesting alternative in cases of missing autografts.

Kinematically aligned total knee arthroplasty limits high tibial forces, differences in tibial forces between compartments, and abnormal tibial contact kinematics during passive flexion.

PubMed

Roth, Joshua D; Howell, Stephen M; Hull, Maury L

2018-06-01

Following total knee arthroplasty (TKA), high tibial forces, large differences in tibial forces between the medial and lateral compartments, and anterior translation of the contact locations of the femoral component on the tibial component during passive flexion indicate abnormal knee function. Because the goal of kinematically aligned TKA is to restore native knee function without soft tissue release, the objectives were to determine how well kinematically aligned TKA limits high tibial forces, differences in tibial forces between compartments, and anterior translation of the contact locations of the femoral component on the tibial component during passive flexion. Using cruciate retaining components, kinematically aligned TKA was performed on thirteen human cadaveric knee specimens with use of manual instruments without soft tissue release. The tibial forces and tibial contact locations were measured in both the medial and lateral compartments from 0° to 120° of passive flexion using a custom tibial force sensor. The average total tibial force (i.e. sum of medial + lateral) ranged from 5 to 116 N. The only significant average differences in tibial force between compartments occurred at 0° of flexion (29 N, p = 0.0008). The contact locations in both compartments translated posteriorly in all thirteen kinematically aligned TKAs by an average of 14 mm (p < 0.0001) and 18 mm (p < 0.0001) in the medial and lateral compartments, respectively, from 0° to 120° of flexion. After kinematically aligned TKA, average total tibial forces due to the soft tissue restraints were limited to 116 N, average differences in tibial forces between compartments were limited to 29 N, and a net posterior translation of the tibial contact locations was observed in all kinematically aligned TKAs during passive flexion from 0° to 120°, which are similar to what has been measured previously in native knees. While confirmation in vivo is warranted, these findings give surgeons who perform kinematically aligned TKA confidence that the alignment method and surgical technique limit high tibial forces, differences in tibial forces between compartments, and anterior translation of the tibial contact locations during passive flexion.

The Effects of Comprehensive Warm-Up Programs on Proprioception, Static and Dynamic Balance on Male Soccer Players

PubMed Central

Daneshjoo, Abdolhamid; Mokhtar, Abdul Halim; Rahnama, Nader; Yusof, Ashril

2012-01-01

Purpose The study investigated the effects of FIFA 11+ and HarmoKnee, both being popular warm-up programs, on proprioception, and on the static and dynamic balance of professional male soccer players. Methods Under 21 year-old soccer players (n = 36) were divided randomly into 11+, HarmoKnee and control groups. The programs were performed for 2 months (24 sessions). Proprioception was measured bilaterally at 30°, 45° and 60° knee flexion using the Biodex Isokinetic Dynamometer. Static and dynamic balances were evaluated using the stork stand test and Star Excursion Balance Test (SEBT), respectively. Results The proprioception error of dominant leg significantly decreased from pre- to post-test by 2.8% and 1.7% in the 11+ group at 45° and 60° knee flexion, compared to 3% and 2.1% in the HarmoKnee group. The largest joint positioning error was in the non-dominant leg at 30° knee flexion (mean error value = 5.047), (p<0.05). The static balance with the eyes opened increased in the 11+ by 10.9% and in the HarmoKnee by 6.1% (p<0.05). The static balance with eyes closed significantly increased in the 11+ by 12.4% and in the HarmoKnee by 17.6%. The results indicated that static balance was significantly higher in eyes opened compared to eyes closed (p = 0.000). Significant improvements in SEBT in the 11+ (12.4%) and HarmoKnee (17.6%) groups were also found. Conclusion Both the 11+ and HarmoKnee programs were proven to be useful warm-up protocols in improving proprioception at 45° and 60° knee flexion as well as static and dynamic balance in professional male soccer players. Data from this research may be helpful in encouraging coaches or trainers to implement the two warm-up programs in their soccer teams. PMID:23251579

Should the Ipsilateral Hamstrings Be Used for Anterior Cruciate Ligament Reconstruction in the Case of Medial Collateral Ligament Insufficiency? Biomechanical Investigation Regarding Dynamic Stabilization of the Medial Compartment by the Hamstring Muscles.

PubMed

Herbort, Mirco; Michel, Philipp; Raschke, Michael J; Vogel, Nils; Schulze, Martin; Zoll, Alexander; Fink, Christian; Petersen, Wolf; Domnick, Christoph

2017-03-01

Semitendinosus and gracilis muscles are frequently harvested for autologous tendon grafts for cruciate ligament reconstruction. This study investigated the joint-stabilizing effects of these hamstring muscles in cases of insufficiency of the medial collateral ligament (MCL). First, both the semitendinosus and gracilis muscles can actively stabilize the joint against valgus moments in the MCL-deficient knee. Second, the stabilizing influence of these muscles decreases with an increasing knee flexion angle. Controlled laboratory study. The kinematics was examined in 10 fresh-frozen human cadaveric knees using a robotic/universal force moment sensor system and an optical tracking system. The knee kinematics under 5- and 10-N·m valgus moments were determined in the different flexion angles of the (1) MCL-intact and (2) MCL-deficient knee using the following simulated muscle loads: (1) 0-N (idle) load, (2) 200-N semitendinosus (ST) load, and (3) 280-N (200/80-N) combined semitendinosus/gracilis (STGT) load. Cutting the MCL increased the valgus angle under all tested conditions and angles compared with the MCL-intact knee by 4.3° to 8.1° for the 5-N·m valgus moment and 6.5° to 11.9° for the 10-N·m valgus moment ( P < .01). The applied 200-N simulated ST load reduced the valgus angle significantly at 0°, 10°, 20°, and 30° of flexion under 5- and 10-N·m valgus moments ( P < .05). At 0°, 10°, and 20° of flexion, these values were close to those for the MCL-intact joint under the respective moments (both P > .05). The combined 280-N simulated STGT load significantly reduced the valgus angle in 0°, 10°, and 20° of flexion under 5- and 10-N·m valgus moments ( P < .05) to values near those for the intact joint (5 N·m: 0°, 10°; 10 N·m: 0°, 10°, 20°; P > .05). In 60° and 90° of flexion, ST and STGT loads did not decrease the resulting valgus angle of the MCL-deficient knee without hamstring loads ( P > .05 vs deficient; P = .0001 vs intact). In this human cadaveric study, semitendinosus and gracilis muscles successfully stabilize valgus moments applied to the MCL-insufficient knee when the knee is near extension. In the valgus-unstable knee, these data suggest that the hamstring muscles should be preserved in (multi-) ligament surgery when possible.

Comparison of Three Methods of Assessing Muscle Strength and Imbalance Ratios of the Knee

PubMed Central

Moss, Crayton L.; Wright, P. Thomas

1993-01-01

Three strength measurement methods for determining muscle strength and imbalance ratios of the knee were compared in 41 (23 female, 18 male) NCAA Division I track and field athletes. Peak quadriceps extensions and hamstring flexions were measured isotonically, isometrically, and isokinetically. Isokinetic measurements were performed on a Cybex II at 60°/s. Isometric extension and flexion measurements were performed using the Nicholas Manual Muscle Tester (Lafayette Instruments; Lafayette, Ind). Isotonic measurements were done on both Universal and Nautilus apparatuses. Testing order was randomized to avoid a treatment order effect. A repeated measures ANOVA and a post hoc Tukey test were used to compare the three methods of assessing strength and imbalance ratios of the knee. Absolute strength values were significantly different according to gender and mode of testing. Bilateral strength imbalance ratios for knee flexion were significantly lower for the Nautilus leg curl machine. Ipsilateral strength imbalance ratios were significantly greater for the Cybex II. Our results indicated that absolute strength values cannot be interchanged between testing modes. Except for Cybex II (ipsilateral) and Nautilus (bilateral knee flexion), strength imbalance ratios could be interchanged. ImagesFig 1.Fig 2.Fig 3.Fig 4.Fig 5.Fig 6.Fig 7.INGING PMID:16558207

Accurate joint space quantification in knee osteoarthritis: a digital x-ray tomosynthesis phantom study

NASA Astrophysics Data System (ADS)

Sewell, Tanzania S.; Piacsek, Kelly L.; Heckel, Beth A.; Sabol, John M.

2011-03-01

The current imaging standard for diagnosis and monitoring of knee osteoarthritis (OA) is projection radiography. However radiographs may be insensitive to markers of early disease such as osteophytes and joint space narrowing (JSN). Relative to standard radiography, digital X-ray tomosynthesis (DTS) may provide improved visualization of the markers of knee OA without the interference of superimposed anatomy. DTS utilizes a series of low-dose projection images over an arc of +/-20 degrees to reconstruct tomographic images parallel to the detector. We propose that DTS can increase accuracy and precision in JSN quantification. The geometric accuracy of DTS was characterized by quantifying joint space width (JSW) as a function of knee flexion and position using physical and anthropomorphic phantoms. Using a commercially available digital X-ray system, projection and DTS images were acquired for a Lucite rod phantom with known gaps at various source-object-distances, and angles of flexion. Gap width, representative of JSW, was measured using a validated algorithm. Over an object-to-detector-distance range of 5-21cm, a 3.0mm gap width was reproducibly measured in the DTS images, independent of magnification. A simulated 0.50mm (+/-0.13) JSN was quantified accurately (95% CI 0.44-0.56mm) in the DTS images. Angling the rods to represent knee flexion, the minimum gap could be precisely determined from the DTS images and was independent of flexion angle. JSN quantification using DTS was insensitive to distance from patient barrier and flexion angle. Potential exists for the optimization of DTS for accurate radiographic quantification of knee OA independent of patient positioning.

Evaluation of spinal internal loads and lumbar curvature under holding static load at different trunk and knee positions.

PubMed

Kahrizi, Sedighe; Parnianpour, Mohammad; Firoozabadi, Seyyed Mohammad; Kasemnejad, Anoshirvan; Karimi, Elham

2007-04-01

A study was performed to investigate how different trunk and knee positions while holding static loads affect the lumbar curvature and internal loads on the lumbar spine at L4-L5. Ten healthy male subjects participated in this study. Two inclinometers were used to evaluate the curvature of lumbar spine, lordosis, while a 3D static biomechanical model was used to predict the spinal compression and shear forces at L4-L5. Eighteen static tasks while holding three level of load (0, 10 and 20 kg), two levels of knee position (45 and 180 degrees of flexion) and three levels of trunk position (neutral, 15 and 30 degree of flexion) were simulated for 10 healthy male subjects. The results of this study revealed that the lordosis of lumbar spine changed to kyphosis with increasing weight of load from 0 to 20 kg in trunk flexion position (p<0.05), but in squatting position (45 degrees knee full flexion) the higher load did not affect the curvature. The results of this study suggested, at a more flexed trunk and standing position with higher loads both external moment and internal loads increased significantly at L4-L5 level but with 45 knee flexion external moment and compression force increased and shear force decreased significantly (p < 0.05). Subjects made more effort to maintain stability of the body in squat position. The highest external moment and compression force were computed at flexed knee and trunk position with highest loads. Hence holding weight in this position must be avoided by implementing ergonomic change to the workplace.

In vitro kinematic measurements of the patellar tendon in two different types of posterior-stabilized total knee arthroplasties.

PubMed

Zhu, Zhonglin; Ding, Hui; Dang, Xiao; Tang, Jing; Zhou, Yixin; Wang, Guangzhi

2010-01-01

Fixed-bearing posterior-stabilized (PS) total knee arthroplasty (TKA) has been used in Asian countries for several years, but few studies have investigated differences in the kinematic properties of the patellar tendon after standard PS TKA as compared to high-flex PS TKA. To quantify the in vitro three-dimensional (3D) kinematics of the patellar tendon during passive high flexion and full extension before and after two different types of PS TKAs. Six fresh-frozen cadaveric knees were tested under the following conditions: the unaltered state, status-post traditional PS prostheses (Simth-nephew GENESIS II) replacement, and status-post high-flexion PS prostheses replacement. The soft tissue around the knee and the quadriceps muscle were preserved, then tested under the load of a specific weight in an Oxford knee rig. We designed a specialized rigid body with four active markers fixed to each bone to track the 3D passive motion of the cadaveric knees. Flexion and extension was controlled by the knee rig and captured by an Optotrak Certus high precision optical tracking system. The attachment sites of the patellar tendon were registered as virtual markers to calculate the 3D kinematics. The patellar tendon of the unaltered knee and both TKA knees showed similar deformation. We found the length of the patellar tendon changed significantly during a motion from full extension to 30°, but there was no significant change in length while undergoing a motion from 30° to full flexion. Both the sagittal plane and coronal plane angles of the patellar tendon decreased after PS TKAs. There was no significant difference in patellar tendon kinematics between the two types of PS TKAs. We believe the changes observed in the sagittal plane and coronal plane angles of the patellar tendon after PS TKAs may influence the extensor mechanism and be an important cause of patella-femoral complications. These data may be used to assess patella-femoral complications after surgery so as to improve the design of high-flexion TKAs for Asians and achieve long-term stability.

Analysis of the load on the knee joint and vertebral column with changes in squatting depth and weight load.

PubMed

Hartmann, Hagen; Wirth, Klaus; Klusemann, Markus

2013-10-01

It has been suggested that deep squats could cause an increased injury risk of the lumbar spine and the knee joints. Avoiding deep flexion has been recommended to minimize the magnitude of knee-joint forces. Unfortunately this suggestion has not taken the influence of the wrapping effect, functional adaptations and soft tissue contact between the back of thigh and calf into account. The aim of this literature review is to assess whether squats with less knee flexion (half/quarter squats) are safer on the musculoskeletal system than deep squats. A search of relevant scientific publications was conducted between March 2011 and January 2013 using PubMed. Over 164 articles were included in the review. There are no realistic estimations of knee-joint forces for knee-flexion angles beyond 50° in the deep squat. Based on biomechanical calculations and measurements of cadaver knee joints, the highest retropatellar compressive forces and stresses can be seen at 90°. With increasing flexion, the wrapping effect contributes to an enhanced load distribution and enhanced force transfer with lower retropatellar compressive forces. Additionally, with further flexion of the knee joint a cranial displacement of facet contact areas with continuous enlargement of the retropatellar articulating surface occurs. Both lead to lower retropatellar compressive stresses. Menisci and cartilage, ligaments and bones are susceptible to anabolic metabolic processes and functional structural adaptations in response to increased activity and mechanical influences. Concerns about degenerative changes of the tendofemoral complex and the apparent higher risk for chondromalacia, osteoarthritis, and osteochondritis in deep squats are unfounded. With the same load configuration as in the deep squat, half and quarter squat training with comparatively supra-maximal loads will favour degenerative changes in the knee joints and spinal joints in the long term. Provided that technique is learned accurately under expert supervision and with progressive training loads, the deep squat presents an effective training exercise for protection against injuries and strengthening of the lower extremity. Contrary to commonly voiced concern, deep squats do not contribute increased risk of injury to passive tissues.

ACL-reconstructed and ACL-deficient individuals show differentiated trunk, hip, and knee kinematics during vertical hops more than 20 years post-injury.

PubMed

Markström, Jonas L; Tengman, Eva; Häger, Charlotte K

2018-02-01

Little is known regarding movement strategies in the long term following injury of the anterior cruciate ligament (ACL), and even less about comparisons of reconstructed and deficient knees in relation to healthy controls. The present purpose was to compare trunk, hip, and knee kinematics during a one-leg vertical hop (VH) ~20 years post-ACL injury between persons treated with surgery and physiotherapy (ACL R ), solely physiotherapy (ACL PT ), and controls (CTRL). Between-leg kinematic differences within groups were also investigated. Sixty-six persons who suffered unilateral ACL injury on average 23 ± 2 years ago (32 ACL R , 34 ACL PT ) and 33 controls performed the VH. Peak trunk, hip, and knee angles during Take-off and Landing phases recorded with a 3D motion capture system were analysed with multivariate statistics. Significant group effects during both Take-off and Landing were found, with ACL PT differing from CTRL in Take-off with a combination of less knee flexion and knee internal rotation, and from both ACL R and CTRL in Landing with less hip and knee flexion, knee internal rotation, and greater hip adduction. ACL R also presented different kinematics to ACL PT and CTRL in Take-off with a combination of greater trunk flexion, hip flexion, hip internal rotation, and less knee abduction, and in Landing with greater trunk flexion and hip internal rotation. Further, different kinematics and hop height were found between legs within groups in both Take-off and Landing for both ACL groups, but not for CTRL. Different kinematics for the injured leg for both ACL groups compared to CTRL and between treatment groups, as well as between legs within treatment groups, indicate long-term consequences of injury. Compensatory mechanisms for knee protection seem to prevail over time irrespective of initial treatment, possibly increasing the risk of re-injury and triggering the development of osteoarthritis. Detailed investigation of movement strategies during the VH provides important information and a more comprehensive evaluation of knee function than merely hop height. More attention should also be given to the trunk and hip in clinics when evaluating movement strategies after ACL injury. Prospective cohort study, Level II.

Kinematic analysis of a posterior-stabilized knee prosthesis.

PubMed

Zhao, Zhi-Xin; Wen, Liang; Qu, Tie-Bing; Hou, Li-Li; Xiang, Dong; Bin, Jia

2015-01-20

The goal of total knee arthroplasty (TKA) is to restore knee kinematics. Knee prosthesis design plays a very important role in successful restoration. Here, kinematics models of normal and prosthetic knees were created and validated using previously published data. Computed tomography and magnetic resonance imaging scans of a healthy, anticorrosive female cadaver were used to establish a model of the entire lower limbs, including the femur, tibia, patella, fibula, distal femur cartilage, and medial and lateral menisci, as well as the anterior cruciate, posterior cruciate, medial collateral, and lateral collateral ligaments. The data from the three-dimensional models of the normal knee joint and a posterior-stabilized (PS) knee prosthesis were imported into finite element analysis software to create the final kinematic model of the TKA prosthesis, which was then validated by comparison with a previous study. The displacement of the medial/lateral femur and the internal rotation angle of the tibia were analyzed during 0-135° flexion. Both the output data trends and the measured values derived from the normal knee's kinematics model were very close to the results reported in a previous in vivo study, suggesting that this model can be used for further analyses. The PS knee prosthesis underwent an abnormal forward displacement compared with the normal knee and has insufficient, or insufficiently aggressive, "rollback" compared with the lateral femur of the normal knee. In addition, a certain degree of reverse rotation occurs during flexion of the PS knee prosthesis. There were still several differences between the kinematics of the PS knee prosthesis and a normal knee, suggesting room for improving the design of the PS knee prosthesis. The abnormal kinematics during early flexion shows that the design of the articular surface played a vital role in improving the kinematics of the PS knee prosthesis.

Young Athletes After Anterior Cruciate Ligament Reconstruction With Single-Leg Landing Asymmetries at the Time of Return to Sport Demonstrate Decreased Knee Function 2 Years Later.

PubMed

Ithurburn, Matthew P; Paterno, Mark V; Ford, Kevin R; Hewett, Timothy E; Schmitt, Laura C

2017-09-01

Previous work shows that young athletes after anterior cruciate ligament reconstruction (ACLR) demonstrate single-leg (SL) landing movement asymmetries at the time of return to sport (RTS); however, the effect of movement asymmetries on longitudinal knee-related function after ACLR has not been examined. Hypothesis/Purpose: The purpose of this study was to examine the effect of SL drop-landing movement symmetry at the time of RTS on knee-related function 2 years later in young athletes after ACLR. The first hypothesis was that young athletes who demonstrated SL drop-landing asymmetries at RTS would demonstrate decreased knee function 2 years later compared with those who demonstrated symmetric SL drop-landing mechanics. The second hypothesis was that SL drop-landing movement symmetry at RTS would be associated with knee functional recovery 2 years later. Cohort study; Level of evidence, 2. This study included 48 young athletes who had undergone ACLR and were assessed at the time of RTS (77% female; mean [±SD] age at RTS, 17.6 ± 2.6 years) and followed for 2 years after RTS. Three sagittal-plane landing variables of interest were calculated using 3-dimensional motion analysis during an SL drop-landing task at the time of RTS: knee flexion excursion, peak internal knee extension moment, and peak trunk flexion. The limb symmetry index (LSI) was calculated for each landing variable using the following: LSI = (involved/uninvolved) × 100%. The LSI was used to divide the cohort into symmetric (SYM) and asymmetric (ASYM) groups for each landing variable: knee flexion excursion (SYM: LSI ≥ 90% [n = 23]; ASYM: LSI < 85% [n = 18]), peak internal knee extension moment (SYM: LSI ≥ 90% [n = 19]; ASYM: LSI < 85% [n = 22]), and peak trunk flexion (SYM: LSI ≤ 105% [n = 25]; ASYM: LSI > 115% [n = 19]). At 2 years after RTS, knee-related function was evaluated using the Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC) subjective knee form, and performance on SL hop tests. Functional recovery was defined based on literature cutoffs for knee-related functional measures. Differences in 2-year function were compared between the symmetry groups using Mann-Whitney U tests because of nonnormality. Logistic regression was used to determine if landing symmetry at the time of RTS would be associated with 2-year knee functional recovery after RTS. The ASYM knee flexion excursion group demonstrated decreased function at 2 years after RTS compared with the SYM group on the KOOS-Pain (ASYM: 93.0 ± 8.2; SYM: 98.4 ± 3.0; P = .008) and the KOOS-Quality of Life (ASYM: 81.6 ± 16.1; SYM: 94.1 ± 9.7; P = .008). Knee flexion excursion was associated with knee functional recovery on the KOOS-Pain and the KOOS-Quality of Life ( P = .033 and P = .012, respectively) at 2 years after RTS, after controlling for the quadriceps strength LSI and graft type. Young athletes after ACLR with asymmetries in knee kinematics at the time of RTS reported decreased self-reported function 2 years later; however, the clinical importance of these differences needs to be further understood.

Lateral trunk lean and medializing the knee as gait strategies for knee osteoarthritis.

PubMed

Gerbrands, T A; Pisters, M F; Theeven, P J R; Verschueren, S; Vanwanseele, B

2017-01-01

To determine (1) if Medial Thrust or Trunk Lean reduces the knee adduction moment (EKAM) the most during gait in patients with medial knee osteoarthritis, (2) if the best overall strategy is the most effective for each patient and (3) if these strategies affect ankle and hip kinetics. Thirty patients with symptomatic medial knee osteoarthritis underwent 3-dimensional gait analysis. Participants received verbal instructions on two gait strategies (Trunk Lean and Medial Thrust) in randomized order after comfortable walking was recorded. The peaks and impulse of the EKAM and strategy-specific kinematic and kinetic variables were calculated for all conditions. Early stance EKAM peak was significantly reduced during Medial Thrust (-29%). During Trunk Lean, early and late stance EKAM peak and EKAM impulse reduced significantly (38%, 21% and -25%, respectively). In 79% of the subjects, the Trunk Lean condition was significantly more effective in reducing EKAM peak than Medial Thrust. Peak ankle dorsi and plantar flexion, knee flexion and hip extension and adduction moments were not significantly increased. Medial Thrust and Trunk Lean reduced the EKAM during gait in patients with knee osteoarthritis. Individual selection of the most effective gait modification strategy seems vital to optimally reduce dynamic knee loading during gait. No detrimental effects on external ankle and hip moments or knee flexion moments were found for these conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

Multijoint kinetic chain analysis of knee extension during the soccer instep kick.

PubMed

Naito, Kozo; Fukui, Yosuke; Maruyama, Takeo

2010-04-01

Although previous studies have shown that motion-dependent interactions between adjacent segments play an important role in producing knee extension during the soccer instep kick, detailed knowledge about the mechanisms underlying those interactions is lacking. The present study aimed to develop a 3-D dynamical model for the multijoint kinetic chain of the instep kick in order to quantify the contributions of the causal dynamical factors to the production of maximum angular velocity during knee extension. Nine collegiate soccer players volunteered to participate in the experiment and performed instep kicking movements while 3-D positional data and the ground reaction force were measured. A dynamical model was developed in the form of a linked system containing 8 segments and 18 joint rotations, and the knee extension/flexion motion was decomposed into causal factors related to muscular moment, gyroscopic moment, centrifugal force, Coriolis force, gravity, proximal endpoint linear acceleration, and external force-dependent terms. The rapid knee extension during instep kicking was found to result almost entirely from kicking leg centrifugal force, trunk rotation muscular moment, kicking leg Coriolis force, and trunk rotation gyroscopic-dependent components. Based on the finding that rapid knee extension during instep kicking stems from multiple dynamical factors, it is suggested that the multijoint kinetic chain analysis used in the present study is more useful for achieving a detailed understanding of the cause of rapid kicking leg movement than the previously used 2-D, two-segment kinetic chain model. The present results also indicated that the centrifugal effect due to the kicking hip flexion angular velocity contributed substantially to the generation of a rapid knee extension, suggesting that the adjustment between the kicking hip flexion angular velocity and the leg configuration (knee flexion angle) is more important for effective instep kicking than other joint kinematics.

Effects of Neuromuscular Fatigue on Quadriceps Strength and Activation and Knee Biomechanics in Individuals Post-Anterior Cruciate Ligament Reconstruction and Healthy Adults.

PubMed

Thomas, Abbey C; Lepley, Lindsey K; Wojtys, Edward M; McLean, Scott G; Palmieri-Smith, Riann M

2015-12-01

Laboratory-based experiment using a pretest/posttest design. To determine the effects of neuromuscular fatigue on quadriceps strength and activation and sagittal and frontal plane knee biomechanics during dynamic landing following anterior cruciate ligament reconstruction (ACLR). Impaired quadriceps central activation occurs post-ACLR, likely altering lower extremity biomechanics. Neuromuscular fatigue similarly reduces volitional muscle activation and impairs neuromuscular control. Upon return to full activity post-ACLR, individuals likely concurrently experience quadriceps central activation deficits and neuromuscular fatigue, though the effects of fatigue on muscle strength and activation and biomechanics post-ACLR are unknown. Seventeen individuals 7 to 10 months post-ACLR and 16 controls participated. Quadriceps strength and central activation ratio were recorded prefatigue and postfatigue, which was induced via sets of double-leg squats. Knee biomechanics were recorded during a dynamic landing activity prefatigue and postfatigue. Both groups demonstrated smaller knee flexion (initial contact, P = .017; peak, P = .004) and abduction (initial contact, P = .005; peak, P = .009) angles postfatigue. The ACLR group had smaller peak knee flexion angles (P<.001) prefatigue and postfatigue than controls. Knee flexion moment was smaller in those post-ACLR than controls prefatigue (P<.001), but not postfatigue (P = .103). Controls had smaller knee flexion moments postfatigue (P = .001). Knee abduction moment was smaller in both groups postfatigue (P = .003). All participants demonstrated significantly lower strength (P<.001) and activation (P = .003) postfatigue. Impaired strength, central activation, and biomechanics were present postfatigue in both groups, suggesting that neuromuscular fatigue may increase noncontact ACL injury risk. However, these changes were not exaggerated in those post-ACLR, likely because they already demonstrated a stiff-legged landing strategy prefatigue.

Femoral graft-tunnel angles in posterior cruciate ligament reconstruction: analysis with 3-dimensional models and cadaveric experiments.

PubMed

Kim, Sung-Jae; Chun, Yong-Min; Kim, Sung-Hwan; Moon, Hong-Kyo; Jang, Jae-Won

2013-07-01

The purpose of this study was to compare four graft-tunnel angles (GTA), the femoral GTA formed by three different femoral tunneling techniques (the outside-in, a modified inside-out technique in the posterior sag position with knee hyperflexion, and the conventional inside-out technique) and the tibia GTA in 3-dimensional (3D) knee flexion models, as well as to examine the influence of femoral tunneling techniques on the contact pressure between the intra-articular aperture of the femoral tunnel and the graft. Twelve cadaveric knees were tested. Computed tomography scans were performed at different knee flexion angles (0°, 45°, 90°, and 120°). Femoral and tibial GTAs were measured at different knee flexion angles on the 3D knee models. Using pressure sensitive films, stress on the graft of the angulation of the femoral tunnel aperture was measured in posterior cruciate ligament reconstructed cadaveric knees. Between 45° and 120° of knee flexion, there were no significant differences between the outside-in and modified inside-out techniques. However, the femoral GTA for the conventional inside-out technique was significantly less than that for the other two techniques (p<0.001). In cadaveric experiments using pressure-sensitive film, the maximum contact pressure for the modified inside-out and outside-in technique was significantly lower than that for the conventional inside-out technique (p=0.024 and p=0.017). The conventional inside-out technique results in a significantly lesser GTA and higher stress at the intra-articular aperture of the femoral tunnel than the outside-in technique. However, the results for the modified inside-out technique are similar to those for the outside-in technique.

The Lower Extremity Biomechanics of Single- and Double-Leg Stop-Jump Tasks

PubMed Central

2011-01-01

The anterior cruciate ligament (ACL) injury is a common occurrence in sports requiring stop-jump tasks. Single- and double-leg stop-jump techniques are frequently executed in sports. The higher risk of ACL injury in single-leg drop landing task compared to a double-leg drop landing task has been identified. However the injury bias between single- and double-leg landing techniques has not been investigated for stop-jump tasks. The purpose of this study was to determine the differences between single- and double-leg stop-jump tasks in knee kinetics that were influenced by the lower extremity kinematics during the landing phase. Ground reaction force, lower extremity kinematics, and knee kinetics data during the landing phase were obtained from 10 subjects performing single- and double-leg stop-jump tasks, using motion-capture system and force palates. Greater peak posterior and vertical ground reaction forces, and peak proximal tibia anterior and lateral shear forces (p < 0.05) during landing phase were observed of single-leg stop-jump. Single-leg stop-jump exhibited smaller hip and knee flexion angle, and knee flexion angular velocity at initial foot contact with the ground (p < 0.05). We found smaller peak hip and knee flexion angles (p < 0.05) during the landing phase of single-leg stop-jump. These results indicate that single-leg landing may have higher ACL injury risk than double-leg landing in stop-jump tasks that may be influenced by the lower extremity kinematics during the landing phase. Key points Non-contact ACL injuries are more likely to occur during the single-leg stop-jump task than during the double-leg stop-jump task. Single-leg stop-jump exhibited greater peak proximal tibia anterior and lateral shear forces, and peak posterior and vertical ground reaction forces during the landing phase than the double-leg stop-jump task. Single-leg stop-jump exhibited smaller hip flexion angle, knee flexion angle, and knee flexion angular velocity at initial foot contact with the ground. Single-leg stop-jump exhibited greater peak knee extension and valgus moment during the landing phase than the double-leg stop-jump task. Single-leg stop-jump extended the hip joint at initial foot contact with the ground. PMID:24149308

A self-aligning knee joint for walking assistance devices.

PubMed

Byungjune Choi; Younbaek Lee; Jeonghun Kim; Minhyung Lee; Jongwon Lee; Se-Gon Roh; Hyundo Choi; Yong-Jae Kim; Jung-Yun Choi

2016-08-01

This paper presents a novel self-aligning knee mechanism for walking assistance devices for the elderly to provide physical gait assistance. Self-aligning knee joints can assist in flexion/extension motions of the knee joint and compensate the knee's transitional movements in the sagittal plane. In order to compensate the center of rotation, which moves with the flexion/extension motion of the human knee joint, a self-aligning knee joint is proposed that adds redundant degrees of freedom (i.e., 2-DoF) to the 1-DoF revolute joint. The key idea of the proposed mechanism is to decouple joint rotations and translations for use in lower-extremity wearable devices. This paper describes the mechanical design of this self-aligning knee mechanism and its implementation on a wearable robot and in preliminary experiments. The performance of the proposed mechanism is verified by simulations and experiments.

Association of baseline knee sagittal dynamic joint stiffness during gait and 2-year patellofemoral cartilage damage worsening in knee osteoarthritis.

PubMed

Chang, A H; Chmiel, J S; Almagor, O; Guermazi, A; Prasad, P V; Moisio, K C; Belisle, L; Zhang, Y; Hayes, K; Sharma, L

2017-02-01

Knee sagittal dynamic joint stiffness (DJS) describes the biomechanical interaction between change in external knee flexion moment and flexion angular excursion during gait. In theory, greater DJS may particularly stress the patellofemoral (PF) compartment and thereby contribute to PF osteoarthritis (OA) worsening. We hypothesized that greater baseline knee sagittal DJS is associated with PF cartilage damage worsening 2 years later. Participants all had OA in at least one knee. Knee kinematics and kinetics during gait were recorded using motion capture systems and force plates. Knee sagittal DJS was computed as the slope of the linear regression line for knee flexion moments vs angles during the loading response phase. Knee magnetic resonance imaging (MRI) scans were obtained at baseline and 2 years later. We assessed the association between baseline DJS and baseline-to-2-year PF cartilage damage worsening using logistic regression with generalized estimating equations (GEE). Our sample had 391 knees (204 persons): mean age 64.2 years (SD 10.0); body mass index (BMI) 28.4 kg/m 2 (5.7); 76.5% women. Baseline knee sagittal DJS was associated with baseline-to-2-year cartilage damage worsening in the lateral (OR = 5.35, 95% CI: 2.37-12.05) and any PF (OR = 2.99, 95% CI: 1.27-7.04) compartment. Individual components of baseline DJS (i.e., change in knee moment or angle) were not associated with subsequent PF disease worsening. Capturing the concomitant effect of knee kinetics and kinematics during gait, knee sagittal DJS is a potentially modifiable risk factor for PF disease worsening. Copyright © 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Association of Baseline Knee Sagittal Dynamic Joint Stiffness during Gait and 2-year Patellofemoral Cartilage Damage Worsening in Knee Osteoarthritis

PubMed Central

Chang, Alison H.; Chmiel, Joan S.; Almagor, Orit; Guermazi, Ali; Prasad, Pottumarthi V.; Moisio, Kirsten C.; Belisle, Laura; Zhang, Yunhui; Hayes, Karen; Sharma, Leena

2016-01-01

Objective Knee sagittal dynamic joint stiffness (DJS) describes the biomechanical interaction between change in external knee flexion moment and flexion angular excursion during gait. In theory, greater DJS may particularly stress the patellofemoral (PF) compartment and thereby contribute to PF osteoarthritis (OA) worsening. We hypothesized that greater baseline knee sagittal DJS is associated with PF cartilage damage worsening 2 years later. Methods Participants all had OA in at least one knee. Knee kinematics and kinetics during gait were recorded using motion capture systems and force plates. Knee sagittal DJS was computed as the slope of the linear regression line for knee flexion moments vs. angles during the loading response phase. Knee MRI scans were obtained at baseline and 2 years later. We assessed the association between baseline DJS and baseline-to-2-year PF cartilage damage worsening using logistic regression with generalized estimating equations. Results Our sample had 391 knees (204 persons): mean age 64.2 years (SD 10.0); BMI 28.4 kg/m2 (5.7); 76.5% women. Baseline knee sagittal DJS was associated with baseline-to-2-year cartilage damage worsening in the lateral (OR=5.35, 95% CI: 2.37–12.05) and any PF (OR=2.99, 95% CI: 1.27–7.04) compartment. Individual components of baseline DJS (i.e., change in knee moment or angle) were not associated with subsequent PF disease worsening. Conclusion Capturing the concomitant effect of knee kinetics and kinematics during gait, knee sagittal DJS is a potentially modifiable risk factor for PF disease worsening. PMID:27729289

Kinematic Patterns Associated with the Vertical Force Produced during the Eggbeater Kick.

PubMed

Oliveira, Nuno; Chiu, Chuang-Yuan; Sanders, Ross H

2015-01-01

The purpose of this study was to determine the kinematic patterns that maximized the vertical force produced during the water polo eggbeater kick. Twelve water polo players were tested executing the eggbeater kick with the trunk aligned vertically and with the upper limbs above water while trying to maintain as high a position as possible out of the water for nine eggbeater kick cycles. Lower limb joint angular kinematics, pitch angles and speed of the feet were calculated. The vertical force produced during the eggbeater kick cycle was calculated using inverse dynamics for the independent lower body segments and combined upper body segments, and a participant-specific second-degree regression equation for the weight and buoyancy contributions. Vertical force normalized to body weight was associated with hip flexion (average, r = 0.691; maximum, r = 0.791; range of motion, r = 0.710), hip abduction (maximum, r = 0.654), knee flexion (average, r = 0.716; minimum, r = 0.653) and knee flexion-extension angular velocity (r = 0.758). Effective orientation of the hips resulted in fast horizontal motion of the feet with positive pitch angles. Vertical motion of the feet was negatively associated with vertical force. A multiple regression model comprising the non-collinear variables of maximum hip abduction, hip flexion range of motion and knee flexion angular velocity accounted for 81% of the variance in normalized vertical force. For high performance in the water polo, eggbeater kick players should execute fast horizontal motion with the feet by having large abduction and flexion of the hips, and fast extension and flexion of the knees.

Effects of upright weight bearing and the knee flexion angle on patellofemoral indices using magnetic resonance imaging in patients with patellofemoral instability.

PubMed

Becher, Christoph; Fleischer, Benjamin; Rase, Marten; Schumacher, Thees; Ettinger, Max; Ostermeier, Sven; Smith, Tomas

2017-08-01

This study analysed the effects of upright weight bearing and the knee flexion angle on patellofemoral indices, determined using magnetic resonance imaging (MRI), in patients with patellofemoral instability (PI). Healthy volunteers (control group, n = 9) and PI patients (PI group, n = 16) were scanned in an open-configuration MRI scanner during upright weight bearing and supine non-weight bearing positions at full extension (0° flexion) and at 15°, 30°, and 45° flexion. Patellofemoral indices included the Insall-Salvati Index, Caton-Deschamp Index, and Patellotrochlear Index (PTI) to determine patellar height and the patellar tilt angle (PTA), bisect offset (BO), and the tibial tubercle-trochlear groove (TT-TG) distance to assess patellar rotation and translation with respect to the femur and alignment of the extensor mechanism. A significant interaction effect of weight bearing by flexion angle was observed for the PTI, PTA, and BO for subjects with PI. At full extension, post hoc pairwise comparisons revealed a significant effect of weight bearing on the indices, with increased patellar height and increased PTA and BO in the PI group. Except for the BO, no such changes were seen in the control group. Independent of weight bearing, flexing the knee caused the PTA, BO, and TT-TG distance to be significantly reduced. Upright weight bearing and the knee flexion angle affected patellofemoral MRI indices in PI patients, with significantly increased values at full extension. The observations of this study provide a caution to be considered by professionals when treating PI patients. These patients should be evaluated clinically and radiographically at full extension and various flexion angles in context with quadriceps engagement. Explorative case-control study, Level III.

In vivo anteroposterior translation after meniscal-bearing total knee arthroplasty: effects of soft tissue conditions and flexion angle.

PubMed

Ishii, Yoshinori; Noguchi, Hideo; Takeda, Mitsuhiro; Sato, Junko; Sakurai, Tetsuya; Toyabe, Shin-Ichi

2014-08-01

Anteroposterior (AP) joint translation is an important indicator of good clinical outcome following total knee arthroplasty (TKA). This study evaluated the in vivo relationship between changes in the degree of voluntary soft tissue tension and flexion angle versus simultaneous AP translation after TKA. A posterior cruciate ligament (PCL)-retaining meniscal-bearing design was investigated in 20 knees of 20 patients. AP translation was measured at 30° and 75° flexion with the KT-2000 arthrometer while patients were anesthetized and non-anesthetized. The mean translations at 30° and 75° were 10.5 and 10.4 mm, respectively, in non-anesthetized patients and 13.8 and 12.7 mm, respectively, in patients under anesthesia. AP translation showed a significant positive correlation with soft tissue tension (p < 0.001), but not with flexion angle (p = 0.366). No interaction was observed between soft tissue tension and the flexion angle in terms of AP translation (p = 0.431). Surgeons should recognize that AP translation is greater in anesthetized patients than in non-anesthetized patients, regardless of the flexion angle, with no significant correlation between flexion angle and translation, regardless of the level of consciousness. Because conformity between the tibial insert and femoral component decreases with flexion, whereas the opposing effects of supporting structures, such as muscles, ligaments, and capsules, increases, proper soft tissue tension, particularly retention of a functional PCL, could have an important role in determining AP translation in the current prosthesis design.

3D in vivo femoro-tibial kinematics of tri-condylar total knee arthroplasty during kneeling activities.

PubMed

Nakamura, Shinichiro; Sharma, Adrija; Kobayashi, Masahiko; Ito, Hiromu; Nakamura, Kenji; Zingde, Sumesh M; Nakamura, Takashi; Komistek, Richard D

2014-01-01

Kneeling position can serve as an important posture, providing stability and balance from a standing position to sitting on the floor or vice-versa. The purpose of the current study was to determine the kinematics during kneeling activities after subjects were implanted with a tri-condylar total knee arthroplasty. Kinematics was evaluated in 54 knees using fluoroscopy and a three-dimensional model fitting approach. The average knee flexion at before contact status, at complete contact and at maximum flexion was 98.1±9.0°, 107.2±6.7°, and 139.6±12.3°, respectively. On average, there was no gross anterior displacement from before contact status to complete contact. Only slight posterior rollback motion of both condyles from complete contact to maximum flexion was observed. Three of 39 (7.7%) knees experienced anterior movement of both condyles more than 2mm from before contact status to complete contact. Reverse rotation pattern from before contact status to complete contact and then normal rotation pattern from complete contact to maximum flexion were observed. Condylar lift-off greater than 1.0 mm was observed in 45 knees (83.3%). The presence of the ball-and-socket joint articulation provides sufficient antero-posterior stability in these designs to enable the patients to kneel safely without the incidence of any dislocation. This study suggests a safe implant design for kneeling. © 2013.

Lower-extremity isokinetic strength profiling in professional rugby league and rugby union.

PubMed

Brown, Scott R; Brughelli, Matt; Griffiths, Peter C; Cronin, John B

2014-03-01

While several studies have documented isokinetic knee strength in junior and senior rugby league players, investigations of isokinetic knee and hip strength in professional rugby union players are limited. The purpose of this study was to provide lower-extremity strength profiles and compare isokinetic knee and hip strength of professional rugby league and rugby union players. 32 professional rugby league and 25 professional rugby union players. Cross-sectional analysis. Isokinetic dynamometry was used to evaluate peak torque and strength ratios of the dominant and nondominant legs during seated knee-extension/ flexion and supine hip-extension/flexion actions at 60°/s. Forwards from both codes were taller and heavier and had a higher body-mass index than the backs of each code. Rugby union forwards produced significantly (P < .05) greater peak torque during knee flexion in the dominant and nondominant legs (ES = 1.81 and 2.02) compared with rugby league forwards. Rugby league backs produced significantly greater hip-extension peak torque in the dominant and nondominant legs (ES = 0.83 and 0.77) compared with rugby union backs. There were no significant differences in hamstring-to-quadriceps ratios between code, position, or leg. Rugby union forwards and backs produced significantly greater knee-flexion-to-hip-extension ratios in the dominant and nondominant legs (ES = 1.49-2.26) than rugby union players. It seems that the joint torque profiles of players from rugby league and union codes differ, which may be attributed to the different demands of each code.

Magnetic resonance evaluation of the knee in children and adolescents with achondroplasia.

PubMed

Akyol, Yakup; Averill, Lauren W; Atanda, Alfred; Kecskemethy, Heidi H; Bober, Michael B; Mackenzie, William G

2015-06-01

Achondroplasia is the most common form of skeletal dysplasia. Although the radiographic features are well described, MRI features of the knee in achondroplasia have not been reported. To describe common MRI characteristics of the knee joint in symptomatic children and adolescents with achondroplasia. We retrospectively evaluated 10 knee MRI examinations in 8 children and young adults (age range 11-20 years, mean 16.3 years) with achondroplasia. We measured modified Insall-Salvati index, knee flexion angle, anterior cruciate ligament (ACL)-Blumensaat line angle, ACL-tibial angle, posterior cruciate ligament (PCL) angle, intercondylar notch width index, and intercondylar notch depth index. We compared our findings with an age- and gender-matched control group of 20 children (age range 15-18 years; mean 16 years) with normal knee MRIs. All 10 knees in the achondroplasia group had discoid lateral meniscus; 8 meniscal tears were identified. Patella baja was present in half of the study cases. Greater knee flexion and increased ACL-Blumensaat line and PCL angles were seen in all achondroplasia knees. ACL-tibial angle was similar in the study and in the control group. Children with achondroplasia had deeper A-shape femoral notches that extended more anteriorly than those seen in the control group. MRI findings were confirmed in all seven knees with arthroscopic correlation. Discoid lateral meniscus, often with tear, is a consistent feature in knee MRIs of symptomatic children and adolescents with achondroplasia. Other findings include patella baja, knee flexion, deep A-shape intercondylar notch, increased ACL-Blumensaat line angle and taut PCL.

Tibiofemoral Contact Mechanics with Horizontal Cleavage Tear and Resection of the Medial Meniscus in the Human Knee.

PubMed

Koh, Jason L; Yi, Seung Jin; Ren, Yupeng; Zimmerman, Todd A; Zhang, Li-Qun

2016-11-02

The meniscus is known to increase the contact area and decrease contact pressure in the tibiofemoral compartments of the knee. Radial tears of the meniscal root attachment along with partial resections of the torn meniscal tissue decrease the contact area and increase pressure; however, there is a lack of information on the effects of a horizontal cleavage tear (HCT) and partial leaf meniscectomy of such tears on tibiofemoral contact pressure and contact area. Twelve fresh-frozen human cadaveric knees were tested under 10 conditions: 5 serial conditions of posterior medial meniscectomy (intact meniscus, HCT, repaired HCT, inferior leaf resection, and resection of both inferior and superior leaves), each at 2 knee flexion angles (0° and 60°) under an 800-N axial load. Tekscan sensors (model 4000) were used to measure the contact pressure and contact area. HCT and HCT repair resulted in small changes in the contact area and an increase in contact pressure compared with the intact condition. Resection of the inferior leaf resulted in significantly decreased contact area (to a mean 82.3% of the intact condition at 0° of flexion and 81.8% at 60° of flexion; p < 0.05) and increased peak contact pressure (a mean 36.3% increase at 0° flexion and 43.2% increase at 60° flexion; p < 0.05) in the medial compartment. Further resection of the remaining superior leaf resulted in additional significant decreases in contact area (to a mean 60.1% of the intact condition at 0° of flexion and 49.7% at 60° of flexion; p < 0.05) and increases in peak contact pressure (a mean 79.2% increase at 0° of flexion and 74.9% increase at 60° of flexion; p < 0.05). Resection of meniscal tissue forming the inferior leaf of an HCT resulted in substantially decreased contact area and increased contact pressure. Additional resection of the superior leaf resulted in a further significant decrease in contact area and increase in contact pressure in the medial compartment. Repair or minimal resection of meniscal tissue of an HCT may be preferred to complete leaf resection to maintain knee tibiofemoral contact mechanics. Copyright © 2016 by The Journal of Bone and Joint Surgery, Incorporated.

Proximal mechanics during stair ascent are more discriminate of females with patellofemoral pain than distal mechanics.

PubMed

de Oliveira Silva, Danilo; Barton, Christian John; Pazzinatto, Marcella Ferraz; Briani, Ronaldo Valdir; de Azevedo, Fábio Mícolis

2016-06-01

Several hypotheses have been proposed to explain the pathomechanisms underlying patellofemoral pain (PFP). Concurrent evaluation of lower limb mechanics in the same PFP population is needed to determine which may be more important to target during rehabilitation. This study aimed to investigate possible differences in rearfoot eversion, hip adduction, and knee flexion during stair ascent; the relationship between these variables; and the discriminatory capability of each in identifying females with PFP. Thirty-six females with PFP and 31 asymptomatic controls underwent three-dimensional kinematic analyses during stair ascent. Between-group comparisons were made for peak rearfoot eversion, hip adduction, and knee flexion. Pearson's correlation coefficients were calculated to evaluate relationships among these parameters. Receiver operating characteristic curves were applied to identify the discriminatory capability of each. Females with PFP ascended stairs with reduced peak knee flexion, greater peak hip adduction and peak rearfoot eversion. Peak hip adduction (>10.6°; sensitivity=67%, specificity=77%) discriminated females with PFP more effectively than rearfoot eversion (>5.0°; sensitivity=58%, specificity=67%). Reduced peak hip adduction was found to be associated with reduced peak knee flexion (r=0.54, p=0.002) in females with PFP. These findings indicate that proximal, local, and distal kinematics should be considered in PFP management, but proximally targeted interventions may be most important. The relationship of reduced knee flexion with reduced hip adduction also indicates a possible compensatory strategy to reduce patellofemoral joint stress, and this may need to be addressed during rehabilitation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Upright weight-bearing CT of the knee during flexion: changes of the patellofemoral and tibiofemoral articulations between 0° and 120°.

PubMed

Hirschmann, Anna; Buck, Florian M; Herschel, Ramin; Pfirrmann, Christian W A; Fucentese, Sandro F

2017-03-01

To prospectively compare patellofemoral and tibiofemoral articulations in the upright weight-bearing position with different degrees of flexion using CT in order to gain a more thorough understanding of the development of diseases of the knee joint in a physiological position. CT scans of the knee in 0°, 30°, 60° flexion in the upright weight-bearing position and in 120° flexion upright without weight-bearing were obtained of 10 volunteers (mean age 33.7 ± 6.1 years; range 24-41) using a cone-beam extremity-CT. Two independent readers quantified tibiofemoral and patellofemoral rotation, tibial tuberosity-trochlear groove distance (TTTG) and patellofemoral distance. Tibiofemoral contact points were assessed in relation to the anteroposterior distance of the tibial plateau. Significant differences between degrees of flexion were sought using Wilcoxon signed-rank test (P < 0.05). With higher degrees of flexion, internal tibiofemoral rotation increased (0°/120° flexion; mean, 0.5° ± 4.5/22.4° ± 7.6); external patellofemoral rotation decreased (10.6° ± 7.6/1.6° ± 4.2); TTTG decreased (11.1 mm ±3.7/-2.4 mm ±6.4) and patellofemoral distance decreased (38.7 mm ±3.0/21.0 mm ±7.0). The CP shifted posterior, more pronounced laterally. Significant differences were found for all measurements at all degrees of flexion (P = 0.005-0.037), except between 30° and 60°. ICC was almost perfect (0.80-0.99), except for the assessment of the CP (0.20-0.96). Knee joint articulations change significantly during flexion using upright weight-bearing CT. Progressive internal tibiofemoral rotation leads to a decrease in the TTTG and a posterior shift of the contact points in higher degrees of flexion. This elucidates patellar malalignment predominantly close to extension and meniscal tears commonly affecting the posterior horns.

Balanced Flexion and Extension Gaps Are Not Always of Equal Size.

PubMed

Kinsey, Tracy L; Mahoney, Ormonde M

2018-04-01

It has been widely accepted in total knee arthroplasty (TKA) that flexion and extension gaps in the disarticulated knee during surgery should be equalized. We hypothesized that tensioning during assessment of the flexion gap can induce temporary widening of the gap due to posterior tibial translation. We aimed to describe posterior tibial translation at flexion gap (90°) assessments and assess the correlation of tibial translation with laxity (flexion space increase) using constrained and non-constrained inserts. Imageless navigation was used to measure flexion angle, tibial position relative to the femoral axis, and lateral/medial laxity in 30 patients undergoing primary TKA. Trialing was conducted using posteriorly stabilized and cruciate retaining trials of the same size to elucidate the association of posterior tibial translation with changes in joint capsule laxity at 90° knee flexion. All patients demonstrated posterior tibial translation during flexion gap assessment relative to their subsequent final implantation [mean ± standard deviation (range), 11.3 ± 4.4 (4-21) mm]. Positive linear correlation [r = 0.69, 95% confidence interval (CI) 0.44-0.84, P ≤ .001] was demonstrated between translations [8.7 ± 2.4 (3-13) mm] and laxity changes [2.9° ± 2.0° (-0.7° to 7.4°)] at 90° of flexion. Posterior tibial translation can cause artifactual widening of the flexion gap during gap balancing in posteriorly stabilized TKA, which can be of sufficient magnitude to alter femoral component size selection for some patients. Recognition and management of these intra-operative dynamics for optimal kinematics could be feasible with the advent of robotic applications. Copyright © 2017 Elsevier Inc. All rights reserved.

Ankle Dorsiflexion Displacement During Landing is Associated With Initial Contact Kinematics but not Joint Displacement.

PubMed

Begalle, Rebecca L; Walsh, Meghan C; McGrath, Melanie L; Boling, Michelle C; Blackburn, J Troy; Padua, Darin A

2015-08-01

The ankle, knee, and hip joints work together in the sagittal plane to absorb landing forces. Reduced sagittal plane motion at the ankle may alter landing strategies at the knee and hip, potentially increasing injury risk; however, no studies have examined the kinematic relationships between the joints during jump landings. Healthy adults (N = 30; 15 male, 15 female) performed jump landings onto a force plate while three-dimensional kinematic data were collected. Joint displacement values were calculated during the loading phase as the difference between peak and initial contact angles. No relationship existed between ankle dorsiflexion displacement during landing and three-dimensional knee and hip displacements. However, less ankle dorsiflexion displacement was associated with landing at initial ground contact with larger hip flexion, hip internal rotation, knee flexion, knee varus, and smaller plantar flexion angles. Findings of the current study suggest that restrictions in ankle motion during landing may contribute to contacting the ground in a more flexed position but continuing through little additional motion to absorb the landing. Transverse plane hip and frontal plane knee positioning may also occur, which are known to increase the risk of lower extremity injury.

Effect of partial meniscectomy at the medial posterior horn on tibiofemoral contact mechanics and meniscal hoop strains in human knees.

PubMed

Seitz, Andreas Martin; Lubomierski, Anja; Friemert, Benedikt; Ignatius, Anita; Dürselen, Lutz

2012-06-01

We examined the influence of partial meniscectomy of 10 mm width on 10 human cadaveric knee joints, as it is performed during the treatment of radial tears in the posterior horn of the medial meniscus, on maximum contact pressure, contact area (CA), and meniscal hoop strain in the lateral and medial knee compartments. In case of 0° and 30° flexion angle, 20% and 50% partial meniscectomy did not influence maximum contact pressure and area. Only in case of 60° knee flexion, 50% partial resection increased medial maximum contact pressure and decreased the medial CA statistically significant. However, 100% partial resection increased maximum contact pressure and decreased CA significantly in the meniscectomized medial knee compartment in all tested knee positions. No significant differences were noted for meniscal hoop strain. From a biomechanical point of view, our in vitro study suggests that the medial joint compartment is not in danger of accelerated cartilage degeneration up to a resection limit of 20% meniscal depth and 10 mm width. Contact mechanics are likely to be more sensitive to partial meniscectomy at higher flexion angles, which has to be further investigated. Copyright © 2011 Orthopaedic Research Society.

Proprioception in patients with posterior cruciate ligament tears: A meta-analysis comparison of reconstructed and contralateral normal knees

PubMed Central

Ko, Seung-Nam

2017-01-01

Posterior cruciate ligament (PCL) reconstruction for patients with PCL insufficiency has been associated with postoperative improvements in proprioceptive function due to mechanoreceptor regeneration. However, it is unclear whether reconstructed PCL or contralateral normal knees have better proprioceptive function outcomes. This meta-analysis was designed to compare the proprioceptive function of reconstructed PCL or contralateral normal knees in patients with PCL insufficiency. All studies that compared proprioceptive function, as assessed with threshold to detect passive movement (TTDPM) or joint position sense (JPS) in PCL reconstructed or contralateral normal knees were included. JPS was calculated by reproducing passive positioning (RPP). Five studies met the inclusion/exclusion criteria for the meta-analysis. The proprioceptive function, defined as TTDPM (95% CI: 0.25 to 0.51°; P<0.00001) and RPP (95% CI: 0.19 to 0.45°; P<0.00001), was significantly different between the reconstructed PCL and contralateral normal knees. The mean difference in angle of error between the reconstructed PCL and contralateral normal knees was 0.06° greater in TTDPM than by RPP. In addition, results from subgroup analyses, based on the starting angles and the moving directions of the knee, that evaluated TTDPM at 15° flexion to 45° extension, TTDPM at 45° flexion to 110° flexion, RPP in flexion, and RPP in extension demonstrated that mean angles of error were significantly greater, by 0.38° (P = 0.0001), 0.36° (P = 0.02), 0.36° (P<0.00001), and 0.23° (P = 0.04), respectively, in reconstructed PCL than in contralateral normal knees. The proprioceptive function of PCL reconstructed knees was decreased, compared with contralateral normal knees, as determined by both TTDPM and RPP. In addition, the amount of loss of proprioception was greater in TTDPM than in RPP, even with minute differences. Results from subgroup analysis, that evaluated the mean angles of error in moving directions through RPP, suggested that the moving direction of flexion has a significantly greater mean for angles of error than the moving direction of extension. Although the level of differences between various parameters were statistically significant, further studies are needed to determine whether the small differences (>1°) of the loss of proprioception are clinically relevant. PMID:28922423

Differences in knee joint kinematics and forces after posterior cruciate retaining and stabilized total knee arthroplasty.

PubMed

Wünschel, Markus; Leasure, Jeremi M; Dalheimer, Philipp; Kraft, Nicole; Wülker, Nikolaus; Müller, Otto

2013-12-01

Posterior cruciate ligament (PCL) retaining (CR) and -sacrificing (PS) total knee arthroplasties (TKA) are widely-used to treat osteoarthritis of the knee joint. The PS design substitutes the function of the PCL with a cam-spine mechanism which may produce adverse changes to joint kinematics and kinetics. CR- and PS-TKA were performed on 11 human knee specimens. Joint kinematics were measured with a dynamic knee simulator and motion tracking equipment. In-situ loads of the PCL and cam-spine were measured with a robotic force sensor system. Partial weight bearing flexions were simulated and external forces were applied. The PS-TKA rotated significantly less throughout the whole flexion range compared to the CR-TKA. Femoral roll back was greater in the PS-TKA; however, this was not correlated with lower quadriceps forces. Application of external loads produced significantly different in-situ force profiles between the TKA systems. Our data demonstrate that the PS-design significantly alters kinematics of the knee joint. Our data also suggest the cam-spine mechanism may have little influence on high flexion kinematics (such as femoral rollback) with most of the load burden shared by supporting implant and soft-tissue structures. Copyright © 2013 Elsevier B.V. All rights reserved.

The Effects of Varying Ankle Foot Orthosis Stiffness on Gait in Children with Spastic Cerebral Palsy Who Walk with Excessive Knee Flexion

PubMed Central

Kerkum, Yvette L.; Buizer, Annemieke I.; van den Noort, Josien C.; Becher, Jules G.; Harlaar, Jaap; Brehm, Merel-Anne

2015-01-01

Introduction Rigid Ankle-Foot Orthoses (AFOs) are commonly prescribed to counteract excessive knee flexion during the stance phase of gait in children with cerebral palsy (CP). While rigid AFOs may normalize knee kinematics and kinetics effectively, it has the disadvantage of impeding push-off power. A spring-like AFO may enhance push-off power, which may come at the cost of reducing the knee flexion less effectively. Optimizing this trade-off between enhancing push-off power and normalizing knee flexion in stance is expected to maximize gait efficiency. This study investigated the effects of varying AFO stiffness on gait biomechanics and efficiency in children with CP who walk with excessive knee flexion in stance. Fifteen children with spastic CP (11 boys, 10±2 years) were prescribed with a ventral shell spring-hinged AFO (vAFO). The hinge was set into a rigid, or spring-like setting, using both a stiff and flexible performance. At baseline (i.e. shoes-only) and for each vAFO, a 3D-gait analysis and 6-minute walk test with breath-gas analysis were performed at comfortable speed. Lower limb joint kinematics and kinetics were calculated. From the 6-minute walk test, walking speed and the net energy cost were determined. A generalized estimation equation (p<0.05) was used to analyze the effects of different conditions. Compared to shoes-only, all vAFOs improved the knee angle and net moment similarly. Ankle power generation and work were preserved only by the spring-like vAFOs. All vAFOs decreased the net energy cost compared to shoes-only, but no differences were found between vAFOs, showing that the effects of spring-like vAFOs to promote push-off power did not lead to greater reductions in walking energy cost. These findings suggest that, in this specific group of children with spastic CP, the vAFO stiffness that maximizes gait efficiency is primarily determined by its effect on knee kinematics and kinetics rather than by its effect on push-off power. Trial Registration Dutch Trial Register NTR3418 PMID:26600039

The Effects of Varying Ankle Foot Orthosis Stiffness on Gait in Children with Spastic Cerebral Palsy Who Walk with Excessive Knee Flexion.

PubMed

Kerkum, Yvette L; Buizer, Annemieke I; van den Noort, Josien C; Becher, Jules G; Harlaar, Jaap; Brehm, Merel-Anne

2015-01-01

Rigid Ankle-Foot Orthoses (AFOs) are commonly prescribed to counteract excessive knee flexion during the stance phase of gait in children with cerebral palsy (CP). While rigid AFOs may normalize knee kinematics and kinetics effectively, it has the disadvantage of impeding push-off power. A spring-like AFO may enhance push-off power, which may come at the cost of reducing the knee flexion less effectively. Optimizing this trade-off between enhancing push-off power and normalizing knee flexion in stance is expected to maximize gait efficiency. This study investigated the effects of varying AFO stiffness on gait biomechanics and efficiency in children with CP who walk with excessive knee flexion in stance. Fifteen children with spastic CP (11 boys, 10±2 years) were prescribed with a ventral shell spring-hinged AFO (vAFO). The hinge was set into a rigid, or spring-like setting, using both a stiff and flexible performance. At baseline (i.e. shoes-only) and for each vAFO, a 3D-gait analysis and 6-minute walk test with breath-gas analysis were performed at comfortable speed. Lower limb joint kinematics and kinetics were calculated. From the 6-minute walk test, walking speed and the net energy cost were determined. A generalized estimation equation (p<0.05) was used to analyze the effects of different conditions. Compared to shoes-only, all vAFOs improved the knee angle and net moment similarly. Ankle power generation and work were preserved only by the spring-like vAFOs. All vAFOs decreased the net energy cost compared to shoes-only, but no differences were found between vAFOs, showing that the effects of spring-like vAFOs to promote push-off power did not lead to greater reductions in walking energy cost. These findings suggest that, in this specific group of children with spastic CP, the vAFO stiffness that maximizes gait efficiency is primarily determined by its effect on knee kinematics and kinetics rather than by its effect on push-off power. Dutch Trial Register NTR3418.

Young Athletes With Quadriceps Femoris Strength Asymmetry at Return to Sport After Anterior Cruciate Ligament Reconstruction Demonstrate Asymmetric Single-Leg Drop-Landing Mechanics.

PubMed

Ithurburn, Matthew P; Paterno, Mark V; Ford, Kevin R; Hewett, Timothy E; Schmitt, Laura C

2015-11-01

Young athletes who have had anterior cruciate ligament (ACL) reconstruction demonstrate suboptimal rates of return to sport, high rates of second ACL injuries, and persistent movement asymmetries. Therefore, the influence of musculoskeletal impairments on movement mechanics in this population needs to be further evaluated. The primary hypothesis was that among young athletes who have had ACL reconstruction, those with greater quadriceps strength asymmetry would demonstrate altered single-leg drop-landing mechanics at return to sport compared with individuals with more symmetric quadriceps strength and also compared with healthy controls (ie, those with no ACL reconstruction). A second hypothesis was that quadriceps strength symmetry would predict single-leg drop-landing symmetry in individuals who have undergone ACL reconstruction. Controlled laboratory study. The study entailed a total of 103 participants (age, 17.4 years) at the time of return to sport after ACL reconstruction and 47 control participants (age, 17.0 years). The quadriceps index (QI) was calculated for isometric quadriceps strength, which was then used to divide the ACL reconstruction participants into high-quadriceps (QI ≥90%; n = 52) and low-quadriceps (QI <85%; n = 41) subgroups. Biomechanical data were collected by use of 3-dimensional motion analysis during a single-leg drop-landing task. The LSI was calculated for kinematic and kinetic sagittal-plane variables of interest during landing. Group differences were compared by use of 1-way analysis of variance and linear regression analyses (α < .05). Both the low- and high-quadriceps groups demonstrated greater limb asymmetry during landing compared with the control group in knee flexion excursion (mean LSI ± SD: low quadriceps, 85.8% ± 15.5% [P < .001]; high quadriceps, 94.2% ± 15.6% [P = .019]; control, 102.7% ± 14.1%), peak trunk flexion angle (low quadriceps, 129.2% ± 36.6% [P < .001]; high quadriceps, 110.5% ± 22.6% [P = .03]; control, 95.5% ± 26.2%), and peak knee extension moment (low quadriceps, 79.5% ± 25.2% [P < .001]; high quadriceps, 89.9% ± 19.8% [P = .005]; control, 102.2% ± 10.9%). Compared with the high-quadriceps group, the low-quadriceps group also demonstrated greater asymmetry during landing in knee flexion excursion (P = .026), peak trunk flexion angle (P = .006), and peak knee extension moment (P = .034). In the ACL reconstruction group, quadriceps strength symmetry predicted symmetry in knee flexion excursion, peak trunk flexion, and peak knee extension moment (all P < .001) and predicted symmetry in peak trunk flexion angle (P < .001) after controlling for graft type, knee-related pain, function with activities of daily living, and sport function. At the time of return to sport, athletes who had undergone ACL reconstruction, including those in both the high- and low-quadriceps groups, demonstrated asymmetry during a single-leg drop-landing task compared with controls. Compensations included increased trunk flexion, decreased knee flexion excursion, and decreased knee extension moments on the involved limb. In addition, individuals in the low-quadriceps group demonstrated greater movement asymmetry compared with individuals in the high-quadriceps group. Restoration of symmetric quadriceps strength after ACL reconstruction is associated with more symmetric mechanics during a single-leg drop-landing movement. However, this appears to be multifactorial, as the high-quadriceps group also demonstrated landing asymmetries. Restoration of symmetric quadriceps strength may improve postoperative athletic participation; however, future study is warranted. © 2015 The Author(s).

Manipulation for stiffness following total knee arthroplasty: when and how often to do it?

PubMed

Desai, Aravind S; Karmegam, Anand; Dramis, Asterios; Board, Tim N; Raut, Videsh

2014-10-01

Stiffness following total knee arthroplasty is a disabling complication. One of the management options of stiffness includes manipulation under anaesthesia, but no real consensus exist on appropriate timing of intervention, and the timing and results of the manipulation under anaesthesia (MUA) are under debate in the literature. Our aim was to determine the efficacy of single and multiple manipulations under anaesthesia following total knee arthroplasty and to determine the most appropriate timing for manipulation. We retrospectively reviewed 86 patients who underwent manipulation for stiffness following primary total knee replacement with at least 1-year follow-up. Range of motion before surgery, at the time of the MUA, immediately after MUA and at 6 weeks and 1 year post-MUA were recorded. At the end of 1 year post-manipulation, manipulations performed at less than 20 weeks, following primary total knee arthroplasty, showed 31° of flexion gain as compared to only 1.5° of flexion gain when manipulation was undertaken after 20 weeks. Of the 86 patients, 21 had multiple manipulations with no significant difference in flexion gain after the second manipulation. Patients on warfarin (26%) had an increased incidence of stiffness and poor flexion gain. This study showed that better results were achieved when manipulation was performed at less than 20 weeks (particularly between 12 and 14 weeks) from primary surgery with no added benefit from re-manipulations.

Analysis of Impingement between Patella Bone and Bearing Post in Cruciate-Substituting High-Flexion Total Knee Arthroplasty

PubMed Central

Chon, Jegyun; Shin, Sangyeop; Jang, Gunil; Jeon, Taehyeon

2016-01-01

Background We investigated the causes of impingement between the patella bone and the bearing post during high flexion in cruciate-substituting total knee arthroplasty and proposed a treatment strategy. Methods This prospective cohort study included 218 cases that had undergone cruciate-substituting total knee arthroplasty from February 2014 to January 2015; a single surgeon performed the operation using the same method without patellar resurfacing in all patients. Results In these patients, the occurrence of impingement was determined by performing more than 120° high knee flexion after inserting a bearing perioperatively. The incidence of impingement was significantly associated with bearing design, femoral implant size, patella bone length, and patella inferior pole angle (p < 0.05). The impingement was resolved by resection of the lower articular side of the patella bone. Conclusions In the cruciate-substituting high-flexion total knee arthroplasty, impingement between the patella bone and bearing post was more common in patients with mobile bearing, small-size femoral component, and a long patella or a large inferior pole angle. In cases of intraoperative impingement between the patella bone and the bearing post, resection in the lower portion of the patella prevented impingement of the bearing with soft tissue or the patella by widening the space between the patella and the bearing post, which in turn prevented postoperative reduction in range of motion. PMID:27247740

Analysis of Impingement between Patella Bone and Bearing Post in Cruciate-Substituting High-Flexion Total Knee Arthroplasty.

PubMed

Chon, Jegyun; Lee, Bongju; Shin, Sangyeop; Jang, Gunil; Jeon, Taehyeon

2016-06-01

We investigated the causes of impingement between the patella bone and the bearing post during high flexion in cruciate-substituting total knee arthroplasty and proposed a treatment strategy. This prospective cohort study included 218 cases that had undergone cruciate-substituting total knee arthroplasty from February 2014 to January 2015; a single surgeon performed the operation using the same method without patellar resurfacing in all patients. In these patients, the occurrence of impingement was determined by performing more than 120° high knee flexion after inserting a bearing perioperatively. The incidence of impingement was significantly associated with bearing design, femoral implant size, patella bone length, and patella inferior pole angle (p < 0.05). The impingement was resolved by resection of the lower articular side of the patella bone. In the cruciate-substituting high-flexion total knee arthroplasty, impingement between the patella bone and bearing post was more common in patients with mobile bearing, small-size femoral component, and a long patella or a large inferior pole angle. In cases of intraoperative impingement between the patella bone and the bearing post, resection in the lower portion of the patella prevented impingement of the bearing with soft tissue or the patella by widening the space between the patella and the bearing post, which in turn prevented postoperative reduction in range of motion.

Evaluation of total knee mechanics using a crouching simulator with a synthetic knee substitute.

PubMed

Lowry, Michael; Rosenbaum, Heather; Walker, Peter S

2016-05-01

Mechanical evaluation of total knees is frequently required for aspects such as wear, strength, kinematics, contact areas, and force transmission. In order to carry out such tests, we developed a crouching simulator, based on the Oxford-type machine, with novel features including a synthetic knee including ligaments. The instrumentation and data processing methods enabled the determination of contact area locations and interface forces and moments, for a full flexion-extension cycle. To demonstrate the use of the simulator, we carried out a comparison of two different total knee designs, cruciate retaining and substituting. The first part of the study describes the simulator design and the methodology for testing the knees without requiring cadaveric knee specimens. The degrees of freedom of the anatomic hip and ankle joints were reproduced. Flexion-extension was obtained by changing quadriceps length, while variable hamstring forces were applied using springs. The knee joint was represented by three-dimensional printed blocks on to which the total knee components were fixed. Pretensioned elastomeric bands of realistic stiffnesses passed through holes in the block at anatomical locations to represent ligaments. Motion capture of the knees during flexion, together with laser scanning and computer modeling, was used to reconstruct contact areas on the bearing surfaces. A method was also developed for measuring tibial component interface forces and moments as a comparative assessment of fixation. The method involved interposing Tekscan pads at locations on the interface. Overall, the crouching machine and the methodology could be used for many different mechanical measurements of total knee designs, adapted especially for comparative or parametric studies. © IMechE 2016.

Quantification of functional brace forces for posterior cruciate ligament injuries on the knee joint: an in vivo investigation.

PubMed

LaPrade, Robert F; Smith, Sean D; Wilson, Katharine J; Wijdicks, Coen A

2015-10-01

Counteracting posterior translation of the tibia with an anterior force on the posterior proximal tibia has been demonstrated clinically to improve posterior knee laxity following posterior cruciate ligament (PCL) injury. This study quantified forces applied to the posterior proximal tibia by two knee braces designed for treatment of PCL injuries. The forces applied by two knee braces to the posterior proximal tibia and in vivo three-dimensional knee kinematics of six adult, male, healthy volunteer subjects (mean ± standard deviation: height, 182.5 ± 5.2 cm; body mass, 83.2 ± 9.3 kg; body mass index, 24.9 ± 1.5 kg/m(2); age, 25.8 ± 2.9 years) were measured using a custom pressure mapping technique and traditional surface marker motion capture techniques, while subjects performed three functional activities. The activities included seated unloaded knee flexion, squatting, and stair descent in a new generation dynamic force (DF) PCL brace and a static force (SF) PCL brace. During unloaded flexion at the lowest force level setting, the force applied by the DF brace increased as a function of flexion angle (slope = 0.7 N/°; p < 0.001) compared to the SF brace effect. Force applied by the SF brace did not significantly change as a function of flexion angle (slope = 0.0 N/°; n.s.). By 45° of flexion, the average force applied by the DF brace (48.1 N) was significantly larger (p < 0.001) than the average force applied by the SF brace (25.0 N). The difference in force continued to increase as flexion angle increased. During stair descent, average force (mean ± standard deviation) at toe off was significantly higher (p = 0.013) for the DF brace (78.7 ± 21.6 N) than the SF brace (37.3 ± 7.2 N). Similar trends were observed for squatting and for the higher force level settings. The DF brace applied forces to the posterior proximal tibia that dynamically increased with increased flexion angle. Additionally, the DF brace applied significantly larger forces at higher flexion angles compared to the SF brace where the PCL is known to experience larger in situ forces. Clinical studies are necessary to determine whether the loading characteristics of the DF brace, which more closely replicated the in situ loading profile of the native PCL, results in long-term improved posterior knee laxity following PCL injury. II.

The effects of knee direction, physical activity and age on knee joint position sense.

PubMed

Relph, Nicola; Herrington, Lee

2016-06-01

Previous research has suggested a decline in knee proprioception with age. Furthermore, regular participation in physical activity may improve proprioceptive ability. However, there is no large scale data on uninjured populations to confirm these theories. The aim of this study was to provide normative knee joint position data (JPS) from healthy participants aged 18-82years to evaluate the effects of age, physical activity and knee direction. A sample of 116 participants across five age groups was used. The main outcome measures were knee JPS absolute error scores into flexion and extension, Tegner activity levels and General Practitioner Physical Activity Questionnaire results. Absolute error scores in to knee flexion were 3.6°, 3.9°, 3.5°, 3.7° and 3.1° and knee extension were 2.7°, 2.5°, 2.9°, 3.4° and 3.9° for ages 15-29, 30-44, 45-59, 60-74 and 75 years old respectively. Knee extension and flexion absolute error scores were significantly different when age group data were pooled. There was a significant effect of age and activity level on joint position sense into knee extension. Age and lower Tegner scores were also negatively correlated to joint position sense into knee extension. The results provide some evidence for a decline in knee joint position sense with age. Further, active populations may have heightened static proprioception compared to inactive groups. Normative knee joint position sense data is provided and may be used by practitioners to identify patients with reduced proprioceptive ability. Copyright © 2016 Elsevier B.V. All rights reserved.

Does joint line elevation after revision knee arthroplasty affect tibio-femoral kinematics, contact pressure or collateral ligament lengths? An in vitro analysis

PubMed Central

Kowalczewski, Jacek B.; Chevalier, Yan; Okon, Tomasz; Innocenti, Bernardo; Bellemans, Johan

2015-01-01

Introduction Correct restoration of the joint line is generally considered as crucial when performing total knee arthroplasty (TKA). During revision knee arthroplasty however, elevation of the joint line occurs frequently. The general belief is that this negatively affects the clinical outcome, but the reasons are still not well understood. Material and methods In this cadaveric in vitro study the biomechanical consequences of joint line elevation were investigated using a previously validated cadaver model simulating active deep knee squats and passive flexion-extension cycles. Knee specimens were sequentially tested after total knee arthroplasty with joint line restoration and after 4 mm joint line elevation. Results The tibia rotated internally with increasing knee flexion during both passive and squatting motion (range: 17° and 7° respectively). Joint line elevation of 4 mm did not make a statistically significant difference. During passive motion, the tibia tended to become slightly more adducted with increasing knee flexion (range: 2°), while it went into slighlty less adduction during squatting (range: –2°). Neither of both trends was influenced by joint line elevation. Also anteroposterior translation of the femoral condyle centres was not affected by joint line elevation, although there was a tendency for a small posterior shift (of about 3 mm) during squatting after joint line elevation. In terms of kinetics, ligaments lengths and length changes, tibiofemoral contact pressures and quadriceps forces all showed the same patterns before and joint line elevation. No statistically significant changes could be detected. Conclusions Our study suggests that joint line elevation by 4 mm in revision total knee arthroplasty does not cause significant kinematic and kinetic differences during passive flexion/extension movement and squatting in the tibio-femoral joint, nor does it affect the elongation patterns of collateral ligaments. Therefore, clinical problems after joint line elevation are probably situated in the patello-femoral joint or caused by joint line elevation of more than 4 mm. PMID:25995746

Progressive Changes in Walking Kinematics and Kinetics After Anterior Cruciate Ligament Injury and Reconstruction: A Review and Meta-Analysis.

PubMed

Slater, Lindsay V; Hart, Joseph M; Kelly, Adam R; Kuenze, Christopher M

2017-09-01

  Anterior cruciate ligament (ACL) injury and ACL reconstruction (ACLR) result in persistent alterations in lower extremity movement patterns. The progression of lower extremity biomechanics from the time of injury has not been described.   To compare the 3-dimensional (3D) lower extremity kinematics and kinetics of walking among individuals with ACL deficiency (ACLD), individuals with ACLR, and healthy control participants from 3 to 64 months after ACLR.   We searched PubMed and Web of Science from 1970 through 2013.   We selected only articles that provided peak kinematic and kinetic values during walking in individuals with ACLD or ACLR and comparison with a healthy control group or the contralateral uninjured limb.   A total of 27 of 511 identified studies were included. Weighted means, pooled standard deviations, and 95% confidence intervals were calculated for the healthy control, ACLD, and ACLR groups at each reported time since surgery. The magnitude of between-groups (ACLR versus ACLD, control, or contralateral limb) differences at each time point was evaluated using Cohen d effect sizes and associated 95% confidence intervals. Peak knee-flexion angle (Cohen d = -0.41) and external knee-extensor moment (Cohen d = -0.68) were smaller in the ACLD than in the healthy control group. Peak knee-flexion angle (Cohen d range = -0.78 to -1.23) and external knee-extensor moment (Cohen d range = -1.39 to -2.16) were smaller in the ACLR group from 10 to 40 months after ACLR. Reductions in external knee-adduction moment (Cohen d range = -0.50 to -1.23) were present from 9 to 42 months after ACLR.   Reductions in peak knee-flexion angle, external knee-flexion moment, and external knee-adduction moment were present in the ACLD and ACLR groups. This movement profile during the loading phase of gait has been linked to knee-cartilage degeneration and may contribute to the development of osteoarthritis after ACLR.

Standard versus physiologic bone preparation in total knee arthroplasty and the effect on joint space opening.

PubMed

Burkhart, Timothy A; Herman, Benjamin V; Perry, Kevin; Vandekerckhove, Pieter-Jan; Howard, James; Lanting, Brent

2017-11-01

Total knee arthroplasty is an effective treatment for osteoarthritis. Restoration of physiologic varus alignment may restore the native soft tissue tension and improve outcomes. Six paired fresh-frozen knee specimens were used to perform total knee arthroplastys. The left and right sides of were randomly assigned to have either a physiologic alignment cut or a standard of care neutral alignment bony cut prior to the implantation. Loads of 100 and 200N were applied at 0, 30, 60, and 90° of flexion and the magnitude of the medial and lateral compartment distraction was measured. The loads were applied with the knee specimen intact and post arthroplasty. The physiologic alignment had no difference between medial and lateral gaps at either load. With 100N of load the physiologic alignment had a greater gap at 90° than at full extension while the standard alignment had significantly more gap at 60° of flexion than full extension. The physiologic alignment had a significantly greater gap with the implant compared to the intact condition at both loads. The standard alignment had no significant difference in overall gap between the implant and intact condition with any load. Although performing a physiologic aligned TKA resulted in medial-lateral soft tissue balance, the flexion gap was found to have greater magnitude than the intact knee. Notably, a neutral aligned TKA was found to be balanced, but also was found to recreate the intact knee flexion gaps. These results suggest that coronal plane stability can be achieved with physiologic alignment objectives, but the clinician needs to be aware of the potential to have greater laxity than the intact and neutral alignment surgical objectives. Copyright © 2017 Elsevier Ltd. All rights reserved.

In-vivo evaluation of the kinematic behavior of an artificial medial meniscus implant: A pilot study using open-MRI.

PubMed

De Coninck, Tineke; Elsner, Jonathan J; Linder-Ganz, Eran; Cromheecke, Michiel; Shemesh, Maoz; Huysse, Wouter; Verdonk, René; Verstraete, Koenraad; Verdonk, Peter

2014-09-01

In this pilot study we wanted to evaluate the kinematics of a knee implanted with an artificial polycarbonate-urethane meniscus device, designed for medial meniscus replacement. The static kinematic behavior of the implant was compared to the natural medial meniscus of the non-operated knee. A second goal was to evaluate the motion pattern, the radial displacement and the deformation of the meniscal implant. Three patients with a polycarbonate-urethane implant were included in this prospective study. An open-MRI was used to track the location of the implant during static weight-bearing conditions, within a range of motion of 0° to 120° knee flexion. Knee kinematics were evaluated by measuring the tibiofemoral contact points and femoral roll-back. Meniscus measurements (both natural and artificial) included anterior-posterior meniscal movement, radial displacement, and meniscal height. No difference (P>0.05) was demonstrated in femoral roll-back and tibiofemoral contact points during knee flexion between the implanted and the non-operated knees. Meniscal measurements showed no significant difference in radial displacement and meniscal height (P>0.05) at all flexion angles, in both the implanted and non-operated knees. A significant difference (P ≤ 0.05) in anterior-posterior movement during flexion was observed between the two groups. In this pilot study, the artificial polycarbonate-urethane implant, indicated for medial meniscus replacement, had no influence on femoral roll-back and tibiofemoral contact points, thus suggesting that the joint maintains its static kinematic properties after implantation. Radial displacement and meniscal height were not different, but anterior-posterior movement was slightly different between the implant and the normal meniscus. Copyright © 2014 Elsevier Ltd. All rights reserved.

Hip- and knee-strength assessments using a hand-held dynamometer with external belt-fixation are inter-tester reliable.

PubMed

Thorborg, Kristian; Bandholm, Thomas; Hölmich, Per

2013-03-01

In football, ice-hockey, and track and field, injuries have been predicted, and hip- and knee-strength deficits quantified using hand-held dynamometry (HHD). However, systematic bias exists when testers of different sex and strength perform the measurements. Belt-fixation of the dynamometer may resolve this. The aim of the present study was therefore to examine the inter-tester reliability concerning strength assessments of isometric hip abduction, adduction, flexion, extension and knee-flexion strength, using HHD with external belt-fixation. Twenty-one healthy athletes (6 women), 30 (8.6) (mean (SD)) years of age, were included. Two physiotherapy students (1 female and 1 male) performed all the measurements after careful instruction and procedure training. Isometric hip abduction, adduction, flexion, extension, and knee-flexion strength were tested. The tester-order and hip-action order were randomised. No systematic between-tester differences (bias) were observed for any of the hip or knee actions. The intra-class correlation coefficients (ICC 2.1) ranged from 0.76 to 0.95. Furthermore, standard errors of measurement in per cent (SEM %) ranged from 5 to 11 %, and minimal detectable change in per cent (MDC %) from 14 to 29 % for the different hip and knee actions. The present study shows that isometric hip- and knee-strength measurements have acceptable inter-tester reliability at the group level, when testing strong individuals, using HHD with belt-fixation. This procedure is therefore perfectly suited for the evaluation and monitoring of strong athletes with hip, groin and hamstring injuries, some of the most common and troublesome injuries in sports. Diagnostic, Level III.

Soldier-relevant loads impact lower limb biomechanics during anticipated and unanticipated single-leg cutting movements.

PubMed

Brown, Tyler N; O'Donovan, Meghan; Hasselquist, Leif; Corner, Brian; Schiffman, Jeffrey M

2014-11-07

This study quantified how body borne load impacts hip and knee biomechanics during anticipated and unanticipated single-leg cutting maneuvers. Fifteen male military personnel performed a series of single-leg cutting maneuvers with three different load configurations (light, ~6 kg, medium, ~20 kg, and heavy, ~40 kg). Subject-based means of the specific lower limb biomechanical variables were submitted to repeated measures ANOVA to test the main and interaction effects of body borne load and movement type. With body borne load, stance time (P<0.001) increased, while larger hip (P=0.027) and knee flexion (P=0.004), and hip adduction (P<0.001) moments, and decreased hip (P=0.002) and knee flexion (P<0.001), and hip adduction (P=0.003) postures were evident. Further, the hip (P<0.001) and ankle (P=0.024) increased energy absorption, while the knee (P=0.020) increased energy generation with body borne load. During the unanticipated maneuvers, the hip (P=0.009) and knee (P=0.032) increased energy generation, and peak hip flexion moment (P=0.002) increased relative to the anticipated movements. With the body borne load, participants adopted biomechanical patterns that decreased their locomotive ability including larger moments and reduced flexion postures of the lower limb. During the single-leg cut, participants used greater energy absorption from the large, proximal muscles of the hip and greater energy generation from the knee with the addition of load. Participant's performance when carrying a range of loads was not compromised by anticipation, as they did not exhibit the hip and knee kinetic and kinematic adaptations previously demonstrated when reacting to an unplanned stimulus. Published by Elsevier Ltd.

Posterior Shift of Contact Point between Femoral Component and Polyethylene in the LCS Rotating Platform Implant under Weight Bearing Condition.

PubMed

Oh, Won Seok; Lee, Yong Seuk; Kim, Byung Kak; Sim, Jae Ang; Lee, Beom Koo

2016-06-01

To analyze the contact mechanics of the femoral component and polyethylene of the Low Contact Stress rotating platform (LCS-RP) in nonweight bearing and weight bearing conditions using full flexion lateral radiographs. From May 2009 to December 2013, 58 knees in 41 patients diagnosed with osteoarthritis and treated with total knee arthroplasty (TKA) were included in this study. TKA was performed using an LCS-RP knee prosthesis. Full flexion lateral radiographs in both weight bearing and nonweight bearing condition were taken at least one month postoperatively (average, 28.8 months). Translation of femoral component was determined by the contact point between the femoral component and polyethylene. Maximum flexion was measured as the angle between the lines drawn at the midpoint of the femur and tibia. Posterior shift of the contact point in LCS-RP TKA was observed under weight bearing condition, which resulted in deeper flexion compared to LCS-RP TKA under nonweight bearing condition. In the LCS-RP TKA, the contact point between the femoral component and polyethylene moved posteriorly under weight bearing condition, and the joint was more congruent and maximum flexion increased with weight bearing.

Comparison of reaction forces on the anterior cruciate and anterolateral ligaments during internal rotation and anterior drawer forces at different flexion angles of the knee joint.

PubMed

Uğur, Levent

2017-12-01

Having a complicated anatomy, the knee joint has been further detailed and a new formation defined, the anterolateral ligament (ALL), in recent studies. While the importance of this ligament, which previously was associated with Segond fractures, was explained via clinical, radiologic and biomechanical studies, and basically, is thought to be a fixator structures for the tibia against internal rotation stress. Although in recent studies efficient surgical treatment was applied to patients who underwent anterior cruciate ligament (ACL) operation, some patients having a positive pivot test highlights the clinical importance of the ALL. The aim of this study is to evaluate reaction forces of different flexion angles on the tibia during internal rotation and anterior drawer tests on both the ALL and ACL, and to examine theimportance of this ligament in knee biomechanics by a finite element analysis method. In this study, normal anatomy knee joint was modelled using Computed Tomography images from lower extremity length in DICOM format. 0°, 15°,30°,45°,60°,75° and 90° angles of flexion were applied, respectively, to these models and reaction force vectors formed on both ligaments were examined separately and as total vector and size by applying internal rotation and anterior drawer forces on each model. Non-linear analysis was conducted using ANSYS (version 17) with the same limit conditions applied to all models. After all models were examined, in general when comparing reaction forces, those on the ACL were found to be higher. However, when vectoral directions were examined, forces on ALL increased with increased flexion ratio and internal rotation momentum. Beyond 30° flexion, the tensile force on the ALL is increased and compressive overload on the ACL occurs. The ALL plays an important role in stability, especially against internal rotation forces, and an increased knee joint flexion ratio increases the stability contribution ratio. In particular, at 30° and higher angles, ACL reflects an antagonist effect and contributes to knee joint stability for rotational and mediolateral transposition. Copyright © 2017 John Wiley & Sons, Ltd.

Measurement of the end-to-end distances between the femoral and tibial insertion sites of the anterior cruciate ligament during knee flexion and with rotational torque.

PubMed

Wang, Joon Ho; Kato, Yuki; Ingham, Sheila J M; Maeyama, Akira; Linde-Rosen, Monica; Smolinski, Patrick; Fu, Freddie H

2012-10-01

The aim of this study was to determine the end-to-end distance changes in anterior cruciate ligament (ACL) fibers during flexion/extension and internal/external rotation of the knee. The positional relation between the femur and tibia of 10 knees was digitized on a robotic system during flexion/extension and with an internal/external rotational torque (5 Nm). The ACL insertion site data, acquired by 3-dimensional scanning, were superimposed on the positional data. The end-to-end distances of 5 representative points on the femoral and tibial insertion sites of the ACL were calculated. The end-to-end distances of all representative points except the most anterior points were longest at full extension and shortest at 90°. The distances of the anteromedial (AM) and posterolateral (PL) bundles were 37.2 ± 2.1 mm and 27.5 ± 2.8 mm, respectively, at full extension and 34.7 ± 2.4 mm and 20.7 ± 2.3 mm, respectively, at 90°. Only 4 knees had an isometric point, which was 1 of the 3 anterior points. Under an internal torque, both bundles became longer with statistical meaning at all flexion angles (P = .005). The end-to-end distances of all points became longest with internal torque at full extension and shortest with an external torque at 90°. Only 4 of 10 specimens had an isometric point at a variable anterior point. The end-to-end distances of the AM and PL bundles were longer in extension and shorter in flexion. The nonisometric tendency of the ACL and the end-to-end distance change during knee flexion/extension and internal/external rotation should be considered during ACL reconstruction to avoid overconstraint of the graft. Copyright © 2012 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Contact Stress and Kinematic Analysis of All-Epiphyseal and Over-the-Top Pediatric Reconstruction Techniques for the Anterior Cruciate Ligament

PubMed Central

McCarthy, Moira M.; Tucker, Scott; Nguyen, Joseph T.; Green, Daniel W.; Imhauser, Carl W.; Cordasco, Frank A.

2014-01-01

Background Anterior cruciate ligament (ACL) injuries are an increasingly recognized problem in the pediatric population. Unfortunately, outcomes with conservative treatment are extremely poor. Furthermore, adult reconstruction techniques may be inappropriate to treat skeletally immature patients due to the risk of physeal complications. “Physeal-sparing” reconstruction techniques exist but their ability to restore knee stability and contact mechanics is not well understood. Purpose (1) To assess the ability of the all-epiphyseal (AE) and over-the-top (OT) reconstructions to restore knee kinematics; (2) to assess whether these reconstructions decrease the high posterior contact stresses seen with ACL deficiency; (3) to determine whether the AE or OT produce abnormal tibiofemoral contact stresses. Hypothesis The AE reconstruction will restore contact mechanics and kinematics similarly to that of the ACL intact knee. Methods Ten fresh-frozen human cadaveric knees were tested using a robotic manipulator. Tibiofemoral motions were recorded with the ACL intact, after sectioning the ACL, and after both reconstructions in each of the 10 specimens. The AE utilized an all-inside technique with tunnels exclusively within the epiphysis and fixed with suspensory cortical fixation devices. The OT had a central and vertical tibial tunnel with an over-the-top femur position and was fixed with staples and posts on both ends. Anterior stability was assessed with 134N anterior force at 0, 15, 30, 60, and 90° of knee flexion. Rotational stability was assessed with combined 8 Nm and 4 Nm of abduction and internal rotation, respectively, at 5, 15, and 30° of knee flexion. Results Both reconstruction techniques offloaded the posterior aspect of the tibial plateau compared to the ACL deficient knee in response to both anterior loads and combined moments as demonstrated by reduced contact stresses in this region at all flexion angles. Compared to the ACL intact condition, both the AE and OT had increased posteromedial contact stresses in response to anterior load at some flexion angles and the OT had increased peripheral posterolateral contact stresses at 15° in response to combined moments. Neither reconstruction completely restored the mid-joint contact stresses. Both reconstruction techniques restored anterior stability at flexion angles less than or equal to 30°. In contrast, neither reconstruction restored anterior stability at 60 and 90° flexion. Both reconstructions restored coupled anterior translation under combined moments. Additionally, the AE over-constrained internal rotation in response to the combined moments by 12% at 15° flexion. Conclusions Both reconstructions provide anterior and rotational stability, and decrease posterior joint contact stresses compared to the ACL deficient knee. However, neither reconstruction restored the contact mechanics and kinematics of the ACL intact knee. Clinical Relevance Since the AE reconstruction has clinical advantages over the OT, our results support the hypothesis that the new AE technique is a potential candidate for use in the skeletally immature athlete. PMID:23613444

Influence of knee flexion angle and transverse drill angle on creation of femoral tunnels in double-bundle anterior cruciate ligament reconstruction using the transportal technique: Three-dimensional computed tomography simulation analysis.

PubMed

Choi, Chong Hyuk; Kim, Sung-Jae; Chun, Yong-Min; Kim, Sung-Hwan; Lee, Su-Keon; Eom, Nam-Kyu; Jung, Min

2018-01-01

The purpose of this study was to find appropriate flexion angle and transverse drill angle for optimal femoral tunnels of anteromedial (AM) bundle and posterolateral (PL) bundle in double-bundle ACL reconstruction using transportal technique. Thirty three-dimensional knee models were reconstructed. Knee flexion angles were altered from 100° to 130° at intervals of 10°. Maximum transverse drill angle (MTA), MTA minus 10° and 20° were set up. Twelve different tunnels were determined by four flexion angles and three transverse drill angles for each bundle. Tunnel length, wall breakage, inter-tunnel communication and graft-bending angle were assessed. Mean tunnel length of AM bundle was >30mm at 120° and 130° of flexion in all transverse drill angles. Mean tunnel length of PL bundle was >30mm during every condition. There were ≥1 cases of wall breakage except at 120° and 130° of flexion with MTA for AM bundle. There was no case of wall breakage for PL bundle. Considering inter-tunnel gap of >2mm without communication and obtuse graft-bending angle, 120° of flexion and MTA could be recommended as optimal condition for femoral tunnels of AM and PL bundles. Flexion angle and transverse drill angle had combined effect on femoral tunnel in double-bundle ACL reconstruction using transportal technique. Achieving flexion angle of 120° and transverse drill angle close to the medial femoral condyle could be recommended as optimal condition for femoral tunnels of AM and PL bundles to avoid insufficient tunnel length, wall breakage, inter-tunnel communication and acute graft-bending angle. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of Proud Large Osteochondral Plugs on Contact Forces and Knee Kinematics: A Robotic Study.

PubMed

Du, Peter Z; Markolf, Keith L; Boguszewski, Daniel V; Yamaguchi, Kent T; Lama, Christopher J; McAllister, David R; Jones, Kristofer J

2018-05-01

Osteochondral allograft (OCA) transplantation is used to treat large focal femoral condylar articular cartilage defects. A proud plug could affect graft survival by altering contact forces (CFs) and knee kinematics. A proud OCA plug will significantly increase CF and significantly alter knee kinematics throughout controlled knee flexion. Controlled laboratory study. Human cadaver knees had miniature load cells, each with a 20-mm-diameter cylinder of native bone/cartilage attached at its exact anatomic position, installed in both femoral condyles at standardized locations representative of clinical defects. Spacers were inserted to create proud plug conditions of +0.5, +1.0, and +1.5 mm. CFs and knee kinematics were recorded as a robot flexed the knee continuously from 0° to 50° under 1000 N of tibiofemoral compression. CFs were increased significantly (vs flush) for all proudness conditions between 0° and 45° of flexion (medial) and 0° to 50° of flexion (lateral). At 20°, the average increases in medial CF for +0.5-mm, +1-mm, and +1.5-mm proudness were +80 N (+36%), +155 N (+70%), and +193 N (+87%), respectively. Corresponding increases with proud lateral plugs were +44 N (+14%), +90 N (+29%), and +118 N (+38%). CF increases for medial plugs at 20° of flexion were significantly greater than those for lateral plugs at all proudness conditions. At 50°, a 1-mm proud lateral plug significantly decreased internal tibial rotation by 15.4° and decreased valgus rotation by 2.5°. A proud medial or lateral plug significantly increased CF between 0° and 45° of flexion. Our results suggest that a medial plug at 20° may be more sensitive to graft incongruity than a lateral plug. The changes in rotational kinematics with proud lateral plugs were attributed to earlier contact between the proud plug's surface and the lateral meniscus, leading to rim impingement with decreased tibial rotation. Increased CF and altered knee kinematics from a proud femoral plug could affect graft viability. Plug proudness of only 0.5 mm produced significant changes in CF and knee kinematics, and the clinically accepted 1-mm tolerance may need to be reexamined in view of our findings.

What clinical characteristics and radiographic parameters are associated with patellofemoral instability after kinematically aligned total knee arthroplasty?

PubMed

Nedopil, Alexander J; Howell, Stephen M; Hull, Maury L

2017-02-01

Thirteen patients presented with patellofemoral instability out of 3212 knees treated with kinematically aligned total knee arthroplasty (KA TKA) during a nine year period. We determined the clinical characteristics and post-operative radiographic parameters associated with patellofemoral instability, and whether re-operation and patient reported outcome measures are different between patients with and without patellofemoral instability. Patients with patellofemoral instability were matched 1:3 to a control cohort based on date of surgery (±3 months), age (±10 years), sex, pre-operative knee deformity (varus or valgus), and implant brand. We analyzed clinical characteristics and seven post-operative radiographic parameters. Patellofemoral instability presented atraumatically (12 of 13) at 5 ± 4.7 months for a 0.4 % incidence at a mean follow-up of 43 ± 36 months. No pre-operative clinical characteristics were associated with instability. Patients with patellofemoral instability had greater flexion of the femoral component (11° versus 5°; p = 0.0012), a trend toward greater external rotation of the tibial component (2° versus 0°; p = 0.2704), more reoperations (9 versus 0; p = 0.0026) and a lower Oxford Knee Score (36 versus 42; p = 0.0045) than controls. Patellofemoral instability after kinematically aligned TKA is infrequent, presents atraumatically, and is associated with greater flexion of the femoral component than the control group. Minimizing flexion of the femoral component might reduce the risk of patellofemoral instability by promoting early engagement of the patella in the trochlear during knee flexion.

Lower limb kinematics of male and female soccer players during a self-selected cutting maneuver: Effects of prolonged activity.

PubMed

McGovern, Andrew; Dude, Christopher; Munkley, Daniel; Martin, Thomas; Wallace, David; Feinn, Richard; Dione, Donald; Garbalosa, Juan C

2015-12-01

Despite the recent emphasis on injury prevention, anterior cruciate ligament (ACL) injury rates remain high. This study aimed to ascertain the effects of prolonged activity on lower limb kinematics during a self-selected cutting maneuver. Angular kinematics were recorded during an agility test performed until the completion time was greater than the mean plus one SD of baseline trials. Cut type was identified and the hip and knee angles at 33 ms post heel strike were determined. A linear mixed effects model assessed the effects of cut type, gender, and activity status on the hip and knee angles. Males performed sidestep cuts more frequently than females. Females increased the incidence of sidestep cuts after prolonged activity. At the hip, a gender-cut type interaction existed for the transverse (p=0.001) and sagittal (p=0.11) planes. Females showed more internal rotation during sidestep and more external rotation and less flexion during crossover cuts. For the frontal plane, a gender-activity status interaction (p = 0.032) was due to no change within females but greater hip adduction during prolonged activity within males. With prolonged activity, both genders displayed less hip (p=0.29) and knee (p=0.009) flexion and more knee (p=0.001) adduction. Females displayed less hip and knee flexion than men (p=0.001). Sidestep may be more risky than crossover cuts. Both genders place themselves in at-risk postures with prolonged activity due to less hip and knee flexion. Copyright © 2015 Elsevier B.V. All rights reserved.

Decreased muscle strength is associated with impaired long-term functional outcome after intramedullary nailing of femoral shaft fracture.

PubMed

Larsen, P; Elsoe, R; Graven-Nielsen, T; Laessoe, U; Rasmussen, S

2015-12-01

To examine the long-term outcome after intramedullary nailing of femoral diaphysial fractures measured as disease-specific patient reported function, walking ability, muscle strength, pain and quality of life (QOL). Cross-sectional study. Retrospective review and follow-up with clinical examination of 48 patients treated with intramedullary nailing after femoral shaft fracture between 2007 and 2010. The patients underwent a clinical examination and assessment of walking ability, maximal muscle strength during knee flexion and extension and hip abduction. Hip disability and Osteoarthritis Outcome Score (HOOS) and questionnaire evaluating QOL (Eq5D-5L) were completed by patients. Fourty-eight patients agreed to participate. Mean time for follow-up was 4.7 years. The mean HOOS scores were 84.9 (Pain), 86.6 (ADL), 85.0 (Symptoms), 72.6 (QOL), and 69.1 (Sport). The mean muscle strength of knee flexion with the injured leg (226.0 N) was significantly lower then knee flexion with the non-injured leg (259.5 N, P < 0.0001). Likewise for knee extension (335.2 vs 406.4 N, P < 0.001) and hip abduction (129.2 vs 156.0 N, P < 0.001). Significant association between HOOS and an increase in the difference in muscle strength were observed as well as between worse HOOS outcome and increasing body mass index. This study showed that decreased muscle strength for knee flexion, knee extension and hip abduction was associated with worse long-term functional outcome measured with a disease-specific questionnaire (HOOS) after intramedullary nailing of femoral shaft fracture.

Reduction Osteotomy vs Pie-Crust Technique as Possible Alternatives for Medial Release in Total Knee Arthroplasty and Compared in a Prospective Randomized Controlled Trial.

PubMed

Ahn, Ji Hyun; Yang, Tae Yeong; Lee, Jang Yun

2016-07-01

To compare the gap change between the pie-crust technique and reduction osteotomy to determine their effects on flexion and extension gaps and their success rates in achieving ligament balancing during total knee arthroplasty. In a prospective randomized controlled trial, 106 total knee arthroplasties were allocated to each group with 53 cases. If there was a narrow medial gap with an imbalance of ≥3 mm after the initial limited medial release, either reduction osteotomy or pie-crust technique was performed. The changes of extension and flexion medial gaps along with the success rate of mediolateral balancing were compared. There was a significant difference in the change of medial gap in knee extension with mean changes of 3.5 ± 0.5 mm and 2.3 ± 0.8 mm in the reduction osteotomy and pie-crust groups, respectively (P < .001). For flexion gap, greater change was found in the pie-crust group compared with the reduction osteotomy group; the mean medial gap changes in knee flexion were 1.1 ± 0.5 mm and 2.3 ± 1.2 mm in the reduction osteotomy and pie-crust groups, respectively. The success rates were 90.6% and 67.9% in reduction osteotomy and pie-crust groups, respectively (P = .007). As an alternative medial release method, reduction osteotomy was more effective in extension gap balancing, and pie-crust technique was more effective in flexion gap balancing. The overall success rate of mediolateral ligament balancing was higher in the reduction osteotomy group than in the pie-crust group. Copyright © 2016 Elsevier Inc. All rights reserved.

Direct measurement of hoop strains in the intact and torn human medial meniscus.

PubMed

Jones, R Spencer; Keene, G C R; Learmonth, D J A; Bickerstaff, D; Nawana, N S; Costi, J J; Pearcy, M J

1996-07-01

OBJECTIVE: To measure the circumferential or hoop strains generated in the medial meniscus during loading of the knee joint and to examine the effect of longitudinal and radial tears in the meniscus on these strain values. DESIGN: An in vitro investigation measuring the circumferential strains in the medial menisci of cadaveric human knees as they were loaded in a materials testing machine. BACKGROUND: The menisci transmit approximately 50% of the load through the knee, the rest being transmitted by direct contact of the articular cartilage. Damage to the menisci will alter the pattern of load transmission as will meniscectomy. This study examined the changes in the mechanics of the meniscus in situ as a result of simulated tears to assess the effect of its load carrying capacity and the implications of surgery to remove part or all of a damaged meniscus. METHODS: Nineteen human cadaveric knees were tested. Windows were made in the joint capsule and strain gauges inserted into the anterior, middle and posterior sections of the medial meniscus. The knees were then loaded to three times body weight at speeds of 50 and 500 mm/min, with the knee joint at 0 degrees and 30 degrees of flexion. The tests were repeated following the creation of a longitudinal or a radial tear in the meniscus. RESULTS: The intact menisci showed significantly less strain in the posterior section compared to the anterior and middle sections (P < 0.003, with strains of 1.54%, 2.86% and 2.65% respectively). With a longitudinal tear this pattern changed with strains decreasing anteriorly and increasing posteriorly. There were also significant differences at different angles of knee joint flexion not seen in the intact meniscus. 50% radial tears reduced the strains anteriorly whilst a complete radial tear completely defunctioned the meniscus. CONCLUSIONS: This study has shown that there are significantly different hoop strains produced in different sections of the medial meniscus under load and the patterns of strain distribution are disturbed by meniscal tears. RELEVANCE: These results provide important data for mathematical models which must include non-uniform behaviour. They also have implications for the surgical management of torn menisci. Undamaged portions should be preserved and the integrity of the circumferential fibres maintained to ensure the menisci retain a load bearing capability.

Longitudinal changes in knee kinematics and moments following knee arthroplasty: a systematic review.

PubMed

Sosdian, L; Dobson, F; Wrigley, T V; Paterson, K; Bennell, K; Dowsey, M; Choong, P; Allison, K; Hinman, R S

2014-12-01

Knee arthroplasty (KA) is recognized as an effective treatment of knee joint osteoarthritis and up to 90% of patients experience substantial pain relief. There has been no systematic review synthesizing the longitudinal changes in gait following KA. The aims of this systematic review were to determine the effects of KA on (i) frontal plane and (ii) sagittal plane kinematic and kinetic parameters during the stance phase of gait. MEDLINE (PubMed), CINAHL, SPORTdiscus (EBSCO), and Cochrane Library (Wiley) were searched until April 10th, 2014. 1,765 articles were identified, of which 19 studies describing 3-dimensional gait analysis pre- and post-KA were included. Study quality was evaluated by two reviewers independently using the Downs and Black checklist. Following KA, in the frontal plane, the maximum knee adduction angle and external knee adduction moment (KAM) tended to decrease. In the sagittal plane, findings suggest that the maximum knee flexion moment is increased. From the ten studies that included a healthy reference group, it was unclear whether gait variables returned to normal following KA. Overall, it appears that KA results in a decreased peak KAM and maximum knee adduction angles, an increased peak knee flexion moment and inconsistent changes in the peak knee flexion angle. Knowledge gaps remain due to methodological inconsistencies across studies, limited statistical analysis, and largely heterogeneous sample populations. More research is needed to determine whether KA restores gait patterns to normal, or if additional rehabilitation may be needed to optimize gait following surgery for osteoarthritis. Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of Knee Joint Angle and Contraction Intensity on Hamstrings Coactivation.

PubMed

Wu, Rui; Delahunt, Eamonn; Ditroilo, Massimiliano; Lowery, Madeleine M; DE Vito, Giuseppe

2017-08-01

This study investigated the effect of knee joint angle and contraction intensity on the coactivation of the hamstring muscles (when acting as antagonists to the quadriceps) in young and older individuals of both sexes. A total of 25 young (24 ± 2.6 yr) and 26 older (70 ± 2.5 yr) healthy men and women participated. Maximal voluntary isometric contraction of the knee extensors and flexors was assessed at two knee joint angles (90° and 60°, 0° = full extension). At each angle, participants performed submaximal contractions of the knee extensors (20%, 50%, and 80% maximal voluntary isometric contraction), whereas surface EMG was simultaneously acquired from the vastus lateralis and biceps femoris muscles to assess the level (EMG root-mean-square) of agonist activation and antagonist coactivation. Subcutaneous adipose tissue in the areas corresponding to surface EMG electrode placements was measured via ultrasonography. The contractions performed at 90° knee flexion demonstrated higher levels of antagonist coactivation (all P < 0.01) and agonist activation (all P < 0.01) as a function of contraction intensity compared with the 60° knee flexion. Furthermore, after controlling for subcutaneous adipose tissue, older participants exhibited a higher level of antagonist coactivation at 60° knee flexion compared with young participants (P < 0.05). The results of the present study suggest that 1) the antagonist coactivation is dependent on knee joint angle and contraction intensity and 2) subcutaneous adipose tissue may affect the measured coactivation level likely because of a cross-talk effect. Antagonist coactivation may play a protective role in stabilizing the knee joint and maintaining constant motor output.

Kinematic Analysis of a Posterior-stabilized Knee Prosthesis

PubMed Central

Zhao, Zhi-Xin; Wen, Liang; Qu, Tie-Bing; Hou, Li-Li; Xiang, Dong; Bin, Jia

2015-01-01

Background: The goal of total knee arthroplasty (TKA) is to restore knee kinematics. Knee prosthesis design plays a very important role in successful restoration. Here, kinematics models of normal and prosthetic knees were created and validated using previously published data. Methods: Computed tomography and magnetic resonance imaging scans of a healthy, anticorrosive female cadaver were used to establish a model of the entire lower limbs, including the femur, tibia, patella, fibula, distal femur cartilage, and medial and lateral menisci, as well as the anterior cruciate, posterior cruciate, medial collateral, and lateral collateral ligaments. The data from the three-dimensional models of the normal knee joint and a posterior-stabilized (PS) knee prosthesis were imported into finite element analysis software to create the final kinematic model of the TKA prosthesis, which was then validated by comparison with a previous study. The displacement of the medial/lateral femur and the internal rotation angle of the tibia were analyzed during 0–135° flexion. Results: Both the output data trends and the measured values derived from the normal knee's kinematics model were very close to the results reported in a previous in vivo study, suggesting that this model can be used for further analyses. The PS knee prosthesis underwent an abnormal forward displacement compared with the normal knee and has insufficient, or insufficiently aggressive, “rollback” compared with the lateral femur of the normal knee. In addition, a certain degree of reverse rotation occurs during flexion of the PS knee prosthesis. Conclusions: There were still several differences between the kinematics of the PS knee prosthesis and a normal knee, suggesting room for improving the design of the PS knee prosthesis. The abnormal kinematics during early flexion shows that the design of the articular surface played a vital role in improving the kinematics of the PS knee prosthesis. PMID:25591565

A functional comparison of conventional knee-ankle-foot orthoses and a microprocessor-controlled leg orthosis system based on biomechanical parameters.

PubMed

Schmalz, Thomas; Pröbsting, Eva; Auberger, Roland; Siewert, Gordon

2016-04-01

The microprocessor-controlled leg orthosis C-Brace enables patients with paretic or paralysed lower limb muscles to use dampened knee flexion under weight-bearing and speed-adapted control of the swing phase. The objective of the present study was to investigate the new technical functions of the C-Brace orthosis, based on biomechanical parameters. The study enrolled six patients. The C-Brace orthosis is compared with conventional leg orthoses (four stance control orthoses, two locked knee-ankle-foot orthoses) using biomechanical parameters of level walking, descending ramps and descending stairs. Ground reaction forces, joint moments and kinematic parameters were measured for level walking as well as ascending and descending ramps and stairs. With the C-Brace, a nearly natural stance phase knee flexion was measured during level walking (mean value 11° ± 5.6°). The maximum swing phase knee flexion angle of the C-Brace approached the normal value of 65° more closely than the stance control orthoses (66° ± 8.5° vs 74° ± 6.4°). No significant differences in the joint moments were found between the C-Brace and stance control orthosis conditions. In contrast to the conventional orthoses, all patients were able to ambulate ramps and stairs using a step-over-step technique with C-Brace (flexion angle 64.6° ± 8.2° and 70.5° ± 12.4°). The results show that the functions of the C-Brace for situation-dependent knee flexion under weight bearing have been used by patients with a high level of confidence. The functional benefits of the C-Brace in comparison with the conventional orthotic mechanisms could be demonstrated most clearly for descending ramps and stairs. The C-Brace orthosis is able to combine improved orthotic function with sustained orthotic safety. © The International Society for Prosthetics and Orthotics 2014.

Soft-tissue tension total knee arthroplasty.

PubMed

Asano, Hiroshi; Hoshino, Akiho; Wilton, Tim J

2004-08-01

It is far from clear how best to define the proper strength of soft-tissue tensioning in total knee arthroplasty (TKA). We attached a torque driver to the Monogram balancer/tensor device and measured soft-tissue tension in full extension and 90 degrees flexion during TKA. In our surgical procedure, when we felt proper soft-tissue tension was being applied, the mean distraction force was noted to be 126N in extension and 121N in flexion. There was no significant correlation between soft-tissue tension and the postoperative flexion angle finally achieved. To the best of our knowledge, this is the first study to assess the actual distraction forces in relation to soft-tissue tension in TKA. Further study may reveal the most appropriate forces to achieve proper soft-tissue tension in the wide variety of circumstances presenting at knee arthroplasty.

Patellar tendon rupture repair using Dall-Miles cable.

PubMed

Shelbourne, K D; Darmelio, M P; Klootwyk, T E

2001-01-01

Ten patients underwent patellar tendon repair with end-to-end suture technique and medial and lateral retinacular repair, as well as reinforcement with a Dall-Miles cable through the patella and tibial tubercle. The cable was tensioned at 60 degrees of flexion to allow immediate range of motion to at least 100 degrees of flexion and to protect the repair from undue tension while healing. Accurate tendon length was obtained from a lateral radiograph of the noninvolved knee in 60 degrees of flexion. Patients were allowed to bear full weight as tolerated postoperatively. A knee immobilizer was worn for approximately 2 weeks when adequate muscular control of the leg was attained. The cable was removed 6-8 weeks postoperatively, at which time range of motion equal to the opposite extremity was sought. Full extension was obtained by 1 week postoperatively. Average postoperative knee flexion was 88 degrees at 2 weeks, 112 degrees at 1 month, 133 at 3 months, and 138 degrees at 6 months compared to flexion of 141 degrees in the noninvolved knee. Mean quadriceps muscle strength 1 year postoperatively was 72%+/-11% of the noninvolved leg. No patient had patella infera or rerupture after surgery. Repair of a patellar tendon rupture with end-to-end techniques reinforced with a Dall-Miles cable allows immediate rehabilitation without the need for prolonged immobilization. This technique allows restoration of full range of motion early postoperatively and enables patients to regain adequate quadriceps strength.

Combined Effects of Lignosus rhinocerotis Supplementation and Resistance Training on Isokinetic Muscular Strength and Power, Anaerobic and Aerobic Fitness Level, and Immune Parameters in Young Males.

PubMed

Chen, Chee Keong; Hamdan, Nor Faeiza; Ooi, Foong Kiew; Wan Abd Hamid, Wan Zuraida

2016-01-01

This study investigated the effects of Lignosus rhinocerotis (LRS) supplementation and resistance training (RT) on isokinetic muscular strength and power, anaerobic and aerobic fitness, and immune parameters in young males. Participants were randomly assigned to four groups: Control (C), LRS, RT, and combined RT-LRS (RT-LRS). Participants in the LRS and RT-LRS groups consumed 500 mg of LRS daily for 8 weeks. RT was conducted 3 times/week for 8 weeks for participants in the RT and RT-LRS groups. The following parameters were measured before and after the intervention period: Anthropometric data, isokinetic muscular strength and power, and anaerobic and aerobic fitness. Blood samples were also collected to determine immune parameters. Isokinetic muscular strength and power were increased ( P < 0.05) in participants of both RT and RT-LRS groups. RT-LRS group had shown increases ( P < 0.05) in shoulder extension peak torque, shoulder flexion and extension average power, knee flexion peak torque, and knee flexion and extension average power. There were also increases ( P < 0.05) in anaerobic power and capacity and aerobic fitness in this group. Similarly, RT group had increases ( P < 0.05) in shoulder flexion average power, knee flexion and extension peak torque, and knee flexion and extension average power. In addition, increases ( P < 0.05) in anaerobic power and capacity, aerobic fitness, T lymphocytes (CD3 and CD4), and B lymphocytes (CD19) counts were observed in the RT group. RT elicited increased isokinetic muscular strength and power, anaerobic and aerobic fitness, and immune parameters among young males. However, supplementation with LRS during RT did not provide additive benefits.

Combined Effects of Lignosus rhinocerotis Supplementation and Resistance Training on Isokinetic Muscular Strength and Power, Anaerobic and Aerobic Fitness Level, and Immune Parameters in Young Males

PubMed Central

Chen, Chee Keong; Hamdan, Nor Faeiza; Ooi, Foong Kiew; Wan Abd Hamid, Wan Zuraida

2016-01-01

Background: This study investigated the effects of Lignosus rhinocerotis (LRS) supplementation and resistance training (RT) on isokinetic muscular strength and power, anaerobic and aerobic fitness, and immune parameters in young males. Methods: Participants were randomly assigned to four groups: Control (C), LRS, RT, and combined RT-LRS (RT-LRS). Participants in the LRS and RT-LRS groups consumed 500 mg of LRS daily for 8 weeks. RT was conducted 3 times/week for 8 weeks for participants in the RT and RT-LRS groups. The following parameters were measured before and after the intervention period: Anthropometric data, isokinetic muscular strength and power, and anaerobic and aerobic fitness. Blood samples were also collected to determine immune parameters. Results: Isokinetic muscular strength and power were increased (P < 0.05) in participants of both RT and RT-LRS groups. RT-LRS group had shown increases (P < 0.05) in shoulder extension peak torque, shoulder flexion and extension average power, knee flexion peak torque, and knee flexion and extension average power. There were also increases (P < 0.05) in anaerobic power and capacity and aerobic fitness in this group. Similarly, RT group had increases (P < 0.05) in shoulder flexion average power, knee flexion and extension peak torque, and knee flexion and extension average power. In addition, increases (P < 0.05) in anaerobic power and capacity, aerobic fitness, T lymphocytes (CD3 and CD4), and B lymphocytes (CD19) counts were observed in the RT group. Conclusions: RT elicited increased isokinetic muscular strength and power, anaerobic and aerobic fitness, and immune parameters among young males. However, supplementation with LRS during RT did not provide additive benefits. PMID:27833721

Mid-term Results of Total Knee Arthroplasty Using PFC Sigma RP-F.

PubMed

Kim, Jun-Young; Cheon, Sang-Ho; Kyung, Hee-Soo

2012-12-01

We compared the mid-term results after total knee arthroplasty (TKA) using PFC Sigma RP-F mobile model with PFC Sigma PS fixed model. We analyzed 45 knees that underwent TKA with PFC Sigma RP-Fn (study group) and 45 knees with PFC Sigma PS (control group). The mean follow-up period was 65 months (range, 60-69 months). The evaluation system of the American knee society was used for clinical and radiological assessment. Also, the maximal knee flexion angle was assessed. The mean maximum flexion angle in the study group (135°) was greater than that in the control group (125°) at the early post-operation & final follow-up period (p=0.033). The range of motion (ROM) in the study group was recovered earlier at the postoperative 6 months, and ROM gain was improved to a greater extent at the final follow-up period (p=0.039). The knee score and function score and radiographic evaluation were no difference between the two groups (p>0.05) at the final follow-up. The two cases of radiolucency in posterior condyle and medial tibial plateau and one case of patellar elongation were seen in the study group. The PFC Sigma RP-F mobile system appears to facilitate greater maximum flexion angle and ROM gain with two cases of radiolucent line.

Design, analysis and verification of a knee joint oncological prosthesis finite element model.

PubMed

Zach, Lukáš; Kunčická, Lenka; Růžička, Pavel; Kocich, Radim

2014-11-01

The aim of this paper was to design a finite element model for a hinged PROSPON oncological knee endoprosthesis and to verify the model by comparison with ankle flexion angle using knee-bending experimental data obtained previously. Visible Human Project CT scans were used to create a general lower extremity bones model and to compose a 3D CAD knee joint model to which muscles and ligaments were added. Into the assembly the designed finite element PROSPON prosthesis model was integrated and an analysis focused on the PEEK-OPTIMA hinge pin bushing stress state was carried out. To confirm the stress state analysis results, contact pressure was investigated. The analysis was performed in the knee-bending position within 15.4-69.4° hip joint flexion range. The results showed that the maximum stress achieved during the analysis (46.6 MPa) did not exceed the yield strength of the material (90 MPa); the condition of plastic stability was therefore met. The stress state analysis results were confirmed by the distribution of contact pressure during knee-bending. The applicability of our designed finite element model for the real implant behaviour prediction was proven on the basis of good correlation of the analytical and experimental ankle flexion angle data. Copyright © 2014 Elsevier Ltd. All rights reserved.

Lower-limb kinematics of single-leg squat performance in young adults.

PubMed

Horan, Sean A; Watson, Steven L; Carty, Christopher P; Sartori, Massimo; Weeks, Benjamin K

2014-01-01

To determine the kinematic parameters that characterize good and poor single-leg squat (SLS) performance. A total of 22 healthy young adults free from musculoskeletal impairment were recruited for testing. For each SLS, both two-dimensional video and three-dimensional motion analysis data were collected. Pelvis, hip, and knee angles were calculated using a reliable and validated lower-limb (LL) biomechanical model. Two-dimensional video clips of SLSs were blindly assessed in random order by eight musculoskeletal physiotherapists using a 10-point ordinal scale. To facilitate between-group comparisons, SLS performances were stratified by tertiles corresponding to poor, intermediate, and good SLS performance. Mean ratings of SLS performance assessed by physiotherapists were 8.3 (SD 0.5), 6.8 (SD 0.7), and 4.0 (SD 0.8) for good, intermediate, and poor squats, respectively. Three-dimensional analysis revealed that people whose SLS performance was assessed as poor exhibited increased hip adduction, reduced knee flexion, and increased medio-lateral displacement of the knee joint centre compared to those whose SLS performance was assessed as good (p≤0.05). Overall, poor SLS performance is characterized by inadequate knee flexion and excessive frontal plane motion of the knee and hip. Future investigations of SLS performance should consider standardizing knee flexion angle to illuminate other influential kinematic parameters.

Anticipatory postural adjustments during cutting manoeuvres in football and their consequences for knee injury risk.

PubMed

Mornieux, Guillaume; Gehring, Dominic; Fürst, Patrick; Gollhofer, Albert

2014-01-01

Anticipatory postural adjustments (APAs), i.e. preparatory positioning of the head, the trunk and the foot, are essential to initiate cutting manoeuvres during football games. The aim of the present study was to determine how APA strategies during cutting manoeuvres are influenced by a reduction of the time available to prepare the movement. Thirteen football players performed different cutting tasks, with directions of cutting either known prior to the task or indicated by a light signal occurring 850, 600 or 500 ms before ground contact. With less time available to prepare the cutting manoeuvre, the head was less orientated towards the cutting direction (P = 0.033) and the trunk was even more rotated in the opposite direction (P = 0.002), while the foot placement was not significantly influenced. Moreover, the induced higher lateral trunk flexion correlated with the increased knee abduction moment (r = 0.41; P = 0.009). Increasing lateral trunk flexion is the main strategy used to successfully perform a cutting manoeuvre when less time is available to prepare the movement. However, higher lateral trunk flexion was associated with an increased knee abduction moment and therefore an increased knee injury risk. Reducing lateral trunk flexion during cutting manoeuvres should be part of training programs seeking the optimisation of APAs.

Increased knee valgus alignment and moment during single-leg landing after overhead stroke as a potential risk factor of anterior cruciate ligament injury in badminton.

PubMed

Kimura, Yuka; Ishibashi, Yasuyuki; Tsuda, Eiichi; Yamamoto, Yuji; Hayashi, Yoshimitsu; Sato, Shuichi

2012-03-01

In badminton, knees opposite to the racket-hand side received anterior cruciate ligament (ACL) injuries during single-leg landing after overhead stroke. Most of them occurred in the backhand-side of the rear court. Comparing lower limb biomechanics during single-leg landing after overhead stroke between the forehand-side and backhand-side court may help explain the different injury rates depending on court position. The knee kinematics and kinetics during single-leg landing after overhead stroke following back-stepping were different between the forehand-side and backhand-side court. Controlled laboratory study. Hip, knee and ankle joint kinematic and knee kinetic data were collected for 17 right-handed female college badminton players using a 3-dimensional motion analysis system. Subjects performed single-left-legged landing after an overhead stroke following left and right back-stepping. The kinematic and kinetic data of the left lower extremities during landing were measured and compared between left and right back-steps. Hip flexion and abduction and knee valgus at the initial contact, hip and knee flexion and knee valgus at the maximum knee flexion and the maximum knee valgus moment were significantly larger for the left back-step than the right back-step (p<0.05). Significant differences in joint kinematics and kinetics of the lower extremity during single-leg landing after overhead stroke were observed between different back-step directions. Increased knee valgus angle and moment following back-stepping to the backhand-side might be related to the higher incidence of ACL injury during single-leg landing after overhead stroke.

A practical solution to reduce soft tissue artifact error at the knee using adaptive kinematic constraints.

PubMed

Potvin, Brigitte M; Shourijeh, Mohammad S; Smale, Kenneth B; Benoit, Daniel L

2017-09-06

Musculoskeletal modeling and simulations have vast potential in clinical and research fields, but face various challenges in representing the complexities of the human body. Soft tissue artifact from skin-mounted markers may lead to non-physiological representation of joint motions being used as inputs to models in simulations. To address this, we have developed adaptive joint constraints on five of the six degree of freedom of the knee joint based on in vivo tibiofemoral joint motions recorded during walking, hopping and cutting motions from subjects instrumented with intra-cortical pins inserted into their tibia and femur. The constraint boundaries vary as a function of knee flexion angle and were tested on four whole-body models including four to six knee degrees of freedom. A musculoskeletal model developed in OpenSim simulation software was constrained to these in vivo boundaries during level gait and inverse kinematics and dynamics were then resolved. Statistical parametric mapping indicated significant differences (p<0.05) in kinematics between bone pin constrained and unconstrained model conditions, notably in knee translations, while hip and ankle flexion/extension angles were also affected, indicating the error at the knee propagates to surrounding joints. These changes to hip, knee, and ankle kinematics led to measurable changes in hip and knee transverse plane moments, and knee frontal plane moments and forces. Since knee flexion angle can be validly represented using skin mounted markers, our tool uses this reliable measure to guide the five other degrees of freedom at the knee and provide a more valid representation of the kinematics for these degrees of freedom. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anterior cruciate ligament injury about 20 years post-treatment: A kinematic analysis of one-leg hop.

PubMed

Tengman, E; Grip, H; Stensdotter, Ak; Häger, C K

2015-12-01

Reduced dynamic knee stability, often evaluated with one-leg hops (OLHs), is reported after anterior cruciate ligament (ACL) injury. This may lead to long-standing altered movement patterns, which are less investigated. 3D kinematics during OLH were explored in 70 persons 23 ± 2 years after ACL injury; 33 were treated with physiotherapy in combination with ACL reconstruction (ACL(R)) and 37 with physiotherapy alone (ACL(PT)). Comparisons were made to 33 matched controls. We analyzed (a) maximal knee joint angles and range of motion (flexion, abduction, rotation); (b) medio-lateral position of the center of mass (COM) in relation to knee and ankle joint centers, during take-off and landing phases. Unlike controls, ACL-injured displayed leg asymmetries: less knee flexion and less internal rotation at take-off and landing and more lateral COM related to knee and ankle joint of the injured leg at landing. Compared to controls, ACL(R) had larger external rotation of the injured leg at landing. ACL(PT) showed less knee flexion and larger external rotation at take-off and landing, and larger knee abduction at Landing. COM was more medial in relation to the knee at take-off and less laterally placed relative to the ankle at landing. ACL injury results in long-term kinematic alterations during OLH, which are less evident for ACL(R). © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The superficial medial collateral ligament is the primary medial restraint to knee laxity after cruciate-retaining or posterior-stabilised total knee arthroplasty: effects of implant type and partial release.

PubMed

Athwal, Kiron K; Daou, Hadi El; Kittl, Christoph; Davies, Andrew J; Deehan, David J; Amis, Andrew A

2016-08-01

The aim of this study was to quantify the contributions of medial soft tissues to stability following cruciate-retaining (CR) or posterior-stabilised (PS) total knee arthroplasty (TKA). Using a robotic system, eight cadaveric knees were subjected to ±90-N anterior-posterior force, ±5-Nm internal-external and ±8-Nm varus-valgus torques at various flexion angles. The knees were tested intact and then with CR and PS implants, and successive cuts of the deep and superficial medial collateral ligaments (dMCL, sMCL) and posteromedial capsule (PMC) quantified the percentage contributions of each structure to restraining the applied loads. In implanted knees, the sMCL restrained valgus rotation (62 % across flexion angles), anterior-posterior drawer (24 and 10 %, respectively) and internal-external rotation (22 and 37 %). Changing from CR TKA to PS TKA increased the load on the sMCL when resisting valgus loads. The dMCL restrained 11 % of external and 13 % of valgus rotations, and the PMC was significant at low flexion angles. This work has shown that medial release in the varus knee should be minimised, as it may inadvertently result in a combined laxity pattern. There is increasing interest in preserving constitutional varus in TKA, and this work argues for preservation of the sMCL to afford the surgeon consistent restraint and maintain a balanced knee for the patient.

Change in collateral ligament length and tibiofemoral movement following joint line variation in TKA.

PubMed

Lin, Kun-Jhih; Wei, Hung-Wen; Huang, Chang-Hung; Liu, Yu-Liang; Chen, Wen-Chuan; McClean, Colin Joseph; Cheng, Cheng-Kung

2016-08-01

The primary intent of total knee arthroplasty is the restoration of normal knee kinematics, with ligamentous constraint being a key influential factor. Displacement of the joint line may lead to alterations in ligament attachment sites relative to knee flexion axis and variance of ligamentous constraints on tibiofemoral movement. This study aimed to investigate collaterals strains and tibiofemoral kinematics with different joint line levels. A previously validated knee model was employed to analyse the change in length of the collateral ligaments and tibiofemoral motion during knee flexion. The models shifted the joint line by 3 and 5 mm both proximally and distally from the anatomical level. The data were captured from full extension to flexion 135°. The elevated joint line revealed a relative increase in distance between ligament attachments for both collateral ligaments in comparison with the anatomical model. Also, tibiofemoral movement decreased with an elevation in the joint line. Conversely, lowering the joint line led to a significant decrease in distance between ligament attachments, but greater tibiofemoral motion. Elevation of the joint line would strengthen the capacity of collateral ligaments for knee motion constraint, whereas a distally shifted joint line might have the advantage of improving tibiofemoral movement by slackening the collaterals. It implies that surgeons can appropriately change the joint line position in accordance with patient's requirement or collateral tensions. A lowered joint line level may improve knee kinematics, whereas joint line elevation could be useful to maintain knee stability. V.

Mobile bearing medial unicompartmental knee arthroplasty in patients whose lifestyles involve high degrees of knee flexion: A 10-14year follow-up study.

PubMed

Choy, Won Sik; Lee, Kwang Won; Kim, Ha Yong; Kim, Kap Jung; Chun, Young Sub; Yang, Dae Suk

2017-08-01

Because Asian populations have different lifestyles, such as squatting and sitting on the floor, from those of Western populations, it is possible that the clinical results and survival rate of unicompartmental knee arthroplasty (UKA) for Asian patients may be different. This study described outcomes of mobile bearing medial UKA for Korean patients. A total of the 164 knees treated with mobile bearing UKAs in 147 patients (14 males and 133 females) were reviewed. The mean follow-up period was 12.1years (range 10.1-14). The clinical outcomes, such as the Hospital for Special Surgery Knee score, the Oxford Knee Score and the Knee Society rating system, showed statistically significant improvement from pre-operative to final follow-up (P<0.05). A total of 26 UKAs (15.8%) required revision; the most common reason was bearing dislocation. The 95% confidence interval of survival rate at 12years was 84.1%, with revision for any reason as the end point. Minimally invasive mobile bearing UKA in Asian patients who required high degrees of knee flexion showed rapid recovery and good clinical outcome. However, they also showed relatively high rates of bearing dislocation and aseptic loosening. Therefore, mobile bearing UKA should only be performed in patients whose lifestyle involves high flexions after carefully considering these risks and benefits. Copyright © 2017 Elsevier B.V. All rights reserved.

The effects of the sagittal plane malpositioning of the patella and concomitant quadriceps hypotrophy on the patellofemoral joint: a finite element analysis.

PubMed

Aksahin, Ertugrul; Kocadal, Onur; Aktekin, Cem N; Kaya, Defne; Pepe, Murad; Yılmaz, Serdar; Yuksel, H Yalcin; Bicimoglu, Ali

2016-03-01

Anterior knee pain is a common symptom after intramedullary nailing in tibia shaft fracture. Moreover, patellofemoral malalignment is also known to be a major reason for anterior knee pain. Patellofemoral malalignment predisposes to increased loading in patellar cartilage. In the previous study, we have demonstrated the quadriceps atrophy and patellofemoral malalignment after intramedullary nailing due to tibia shaft fracture. In this study, our aim was to clarify the effects of quadriceps atrophy and patellofemoral malalignment with the pathologic loading on the joint cartilage. Mesh models of patellofemoral joint were constructed with CT images and integrated with soft tissue components such as menisci and ligaments. Physiological and sagittal tilt models during extension and flexion at 15°, 30° and 60° were created generating eight models. All the models were applied with 137 N force to present the effects of normal loading and 115.7 N force for the simulation of quadriceps atrophy. Different degrees of loading were applied to evaluate the joint contact area and pressure value with the finite element analysis. There was increased patellofemoral contact area in patellar tilt models with respect to normal models. The similar loading patterns were diagnosed in all models at 0° and 15° knee flexion when 137 N force was applied. Higher loading values were obtained at 30° and 60° knee flexions in sagittal tilt models. Furthermore, in the sagittal tilt models, in which the quadriceps atrophy was simulated, the loadings at 30° and 60° knee flexion were higher than in the physiological ones. Sagittal malalignment of the patellofemoral joint is a new concept that results in different loading patterns in the patellofemoral joint biomechanics. This malalignment in sagittal plane leads to increased loading values on the patellofemoral joint at 30° and 60° of the knee flexions. This new concept should be kept in mind during the course of diagnosis and treatment in patients with anterior knee pain. Definition of the exact biomechanical effects of the sagittal tilting will lead to the development of new treatment modalities.

Acute Lower Extremity Running Kinematics After a Hamstring Stretch

PubMed Central

Davis Hammonds, Autumn L.; Laudner, Kevin G.; McCaw, Steve; McLoda, Todd A.

2012-01-01

Context: Limited passive hamstring flexibility might affect kinematics, performance, and injury risk during running. Pre-activity static straight-leg raise stretching often is used to gain passive hamstring flexibility. Objective: To investigate the acute effects of a single session of passive hamstring stretching on pelvic, hip, and knee kinematics during the swing phase of running. Design: Randomized controlled clinical trial. Setting: Biomechanics research laboratory. Patients or Other Participants: Thirty-four male (age = 21.2 ± 1.4 years) and female (age = 21.3±2.0 years) recreational athletes. Intervention(s): Participants performed treadmill running pretests and posttests at 70% of their age-predicted maximum heart rate. Pelvis, hip, and knee joint angles during the swing phase of 5 consecutive gait cycles were collected using a motion analysis system. Right and left hamstrings of the intervention group participants were passively stretched 3 times for 30 seconds in random order immediately after the pretest. Control group participants performed no stretching or movement between running sessions. Main Outcome Measure(s): Six 2-way analyses of variance to determine joint angle differences between groups at maximum hip flexion and maximum knee extension with an α level of .008. Results: Flexibility increased between pretest and post-test in all participants (F1,30 = 80.61, P<.001). Anterior pelvic tilt (F1,30 = 0.73, P=.40), hip flexion (F1,30 = 2.44, P=.13), and knee extension (F1,30 = 0.06, P=.80) at maximum hip flexion were similar between groups throughout testing. Anterior pelvic tilt (F1,30 = 0.69, P=.41), hip flexion (F1,30 = 0.23, P=.64), and knee extension (F1,30 = 3.38, P=.62) at maximum knee extension were similar between groups throughout testing. Men demonstrated greater anterior pelvic tilt than women at maximum knee extension (F1,30 = 13.62, P=.001). Conclusions: A single session of 3 straight-leg raise hamstring stretches did not change pelvis, hip, or knee running kinematics. PMID:22488225

Different Exercise Training Interventions and Drop-Landing Biomechanics in High School Female Athletes

PubMed Central

Pfile, Kate R.; Hart, Joseph M.; Herman, Daniel C.; Hertel, Jay; Kerrigan, D. Casey; Ingersoll, Christopher D.

2013-01-01

Context: Anterior cruciate ligament (ACL) injuries are common in female athletes and are related to poor neuromuscular control. Comprehensive neuromuscular training has been shown to improve biomechanics; however, we do not know which component of neuromuscular training is most responsible for the changes. Objective: To assess the efficacy of either a 4-week core stability program or plyometric program in altering lower extremity and trunk biomechanics during a drop vertical jump (DVJ). Design: Cohort study. Setting: High school athletic fields and motion analysis laboratory. Patients or Other Participants: Twenty-three high school female athletes (age = 14.8 ± 0.8 years, height = 1.7 ± 0.07 m, mass = 57.7 ± 8.5 kg). Intervention(s): Independent variables were group (core stability, plyometric, control) and time (pretest, posttest). Participants performed 5 DVJs at pretest and posttest. Intervention participants engaged in a 4-week core stability or plyometric program. Main Outcome Measure(s): Dependent variables were 3-dimensional hip, knee, and trunk kinetics and kinematics during the landing phase of a DVJ. We calculated the group means and associated 95% confidence intervals for the first 25% of landing. Cohen d effect sizes with 95% confidence intervals were calculated for all differences. Results: We found within-group differences for lower extremity biomechanics for both intervention groups (P ≤ .05). The plyometric group decreased the knee-flexion and knee internal-rotation angles and the knee-flexion and knee-abduction moments. The core stability group decreased the knee-flexion and knee internal-rotation angles and the hip-flexion and hip internal-rotation moments. The control group decreased the knee external-rotation moment. All kinetic changes had a strong effect size (Cohen d > 0.80). Conclusions: Both programs resulted in biomechanical changes, suggesting that both types of exercises are warranted for ACL injury prevention and should be implemented by trained professionals. PMID:23768121

Repeated Kicking Actions in Karate: Effect on Technical Execution in Elite Practitioners.

PubMed

Quinzi, Federico; Camomilla, Valentina; Di Mario, Alberto; Felici, Francesco; Sbriccoli, Paola

2016-04-01

Training in martial arts is commonly performed by repeating a technical action continuously for a given number of times. This study aimed to investigate if the repetition of the task alters the proper technical execution, limiting the training efficacy for the technical evaluation during competition. This aim was pursued analyzing lower-limb kinematics and muscle activation during repeated roundhouse kicks. Six junior karate practitioners performed continuously 20 repetitions of the kick. Hip and knee kinematics and sEMG of vastus lateralis, biceps (BF), and rectus femoris were recorded. For each repetition, hip abduction-adduction and flexion-extension and knee flexion-extension peak angular displacements and velocities, agonist and antagonist muscle activation were computed. Moreover, to monitor for the presence of myoelectric fatigue, if any, the median frequency of the sEMG was computed. All variables were normalized with respect to their individual maximum observed during the sequence of kicks. Linear regressions were fitted to each normalized parameter to test its relationship with the repetition number. Linear-regression analysis showed that, during the sequence, the athletes modified their technique: Knee flexion, BF median frequency, hip abduction, knee-extension angular velocity, and BF antagonist activation significantly decreased. Conversely, hip flexion increased significantly. Since karate combat competitions require proper technical execution, training protocols combining severe fatigue and technical actions should be carefully proposed because of technique adaptations. Moreover, trainers and karate masters should consider including specific strength exercises for the BF and more generally for knee flexors.

Quasi-stiffness of the knee joint in flexion and extension during the golf swing.

PubMed

Choi, Ahnryul; Sim, Taeyong; Mun, Joung Hwan

2015-01-01

Biomechanical understanding of the knee joint during a golf swing is essential to improve performance and prevent injury. In this study, we quantified the flexion/extension angle and moment as the primary knee movement, and evaluated quasi-stiffness represented by moment-angle coupling in the knee joint. Eighteen skilled and 23 unskilled golfers participated in this study. Six infrared cameras and two force platforms were used to record a swing motion. The anatomical angle and moment were calculated from kinematic and kinetic models, and quasi-stiffness of the knee joint was determined as an instantaneous slope of moment-angle curves. The lead knee of the skilled group had decreased resistance duration compared with the unskilled group (P < 0.05), and the resistance duration of the lead knee was lower than that of the trail knee in the skilled group (P < 0.01). The lead knee of the skilled golfers had greater flexible excursion duration than the trail knee of the skilled golfers, and of both the lead and trail knees of the unskilled golfers. These results provide critical information for preventing knee injuries during a golf swing and developing rehabilitation strategies following surgery.

Stance control knee mechanism for lower-limb support in hybrid neuroprosthesis

PubMed Central

To, Curtis S.; Kobetic, Rudi; Bulea, Thomas C.; Audu, Musa L.; Schnellenberger, John R.; Pinault, Gilles; Triolo, Ronald J.

2014-01-01

A hydraulic stance control knee mechanism (SCKM) was developed to fully support the knee against flexion during stance and allow uninhibited motion during swing for individuals with paraplegia using functional neuromuscular stimulation (FNS) for gait assistance. The SCKM was optimized for maximum locking torque for body-weight support and minimum resistance when allowing for free knee motion. Ipsilateral and contralateral position and force feedback were used to control the SCKM. Through bench and nondisabled testing, the SCKM was shown to be capable of supporting up to 70 N-m, require no more than 13% of the torque achievable with FNS to facilitate free motion, and responsively and repeatedly unlock under an applied flexion knee torque of up to 49 N-m. Preliminary tests of the SCKM with an individual with paraplegia demonstrated that it could support the body and maintain knee extension during stance without the stimulation of the knee extensor muscles. This was achieved without adversely affecting gait, and knee stability was comparable to gait assisted by knee extensor stimulation during stance. PMID:21938668

Relationship between selected measures of strength and hip and knee excursion during unilateral and bilateral landings in women.

PubMed

McCurdy, Kevin; Walker, John; Armstrong, Rusty; Langford, George

2014-09-01

The purpose of this study was to compare the relationship between several measures of single-joint, isometric, eccentric, and squat strength and unilateral and bilateral landing mechanics at the hip and knee in women. Twenty six healthy female subjects with previous athletic experience (height, 165.1 ± 7.01 cm; mass, 60.91 ± 7.14 kg; age, 20.9 ± 1.62 years) participated in this study. Hip and knee mechanics were measured using the MotionMonitor capture system (Innovative Sports Training, Inc.) with 3-dimensional electromagnetic sensors during bilateral (60 cm) and unilateral drop jumps (30 cm). On a separate day, isometric hip extension, external rotation, and abduction strength (lbs) were measured using a handheld dynamometer (Hoggan Health Industries, Inc.). Eccentric and isometric knee strength were measured on the Biodex IV Isokinetic Dynamometer (Biodex Medical Systems, Inc.). Free weight was used to measure the bilateral squat and a modified single-leg squat. The strongest correlations were found between squat strength and knee valgus (-0.77 ≤ r ≤ -0.83) and hip adduction (-0.5 ≤ r ≤ -0.65). After controlling for squat strength, hip external rotation strength and unilateral knee valgus (-0.41), hip abduction strength and bilateral knee valgus (-0.43), and knee flexion strength and bilateral hip adduction (-0.57) remained significant. Eccentric knee flexion strength and unilateral knee internal rotation was the only significant correlation for eccentric strength (-0.40). Squat strength seems to be the best predictor of knee valgus and was consistently related to hip adduction. Isometric and eccentric measures demonstrated few significant correlations with hip and knee excursion while demonstrating a low-to-moderate relationship. Hip and knee flexion and rotation do not seem to be related to strength. Squat strength should receive consideration during risk assessment for noncontact knee injury.

Nils Silfverskiöld (1888-1957) and gastrocnemius contracture.

PubMed

Singh, Dishan

2013-06-01

Nils Silfverskiöld was an orthopaedic surgeon, Swedish aristocrat, bon vivant, Olympic gymnast, left wing intellectual and anti-Nazi who described that the force required to dorsiflex the ankle in spastic equinus contracture decreased with knee flexion in isolated gastrocnemius contracture. He advocated detaching the origins of the gastrocnemii from the femur and reattaching them to the tibia. The Silfverskiöld knee flexion test has now also been adapted to distinguish between isolated gastrocnemius contracture and combined shortening of the gastrocnemius-soleus complex in non-spastic contracture by measuring the range of ankle dorsiflexion with the knee flexed and the knee straight. Copyright © 2012 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

A Comparison of 2 Tibial Inserts of Different Constraint for Cruciate-Retaining Primary Total Knee Arthroplasty: An Additional Tool for Balancing the Posterior Cruciate Ligament.

PubMed

Emerson, Roger H; Barrington, John W; Olugbode, Seun A; Alnachoukati, Omar K

2016-02-01

Frequently, a normal posterior-cruciate ligament (PCL) is removed at the surgeon's discretion, converting the normal 4-ligament knee to a 2-ligament knee, thus eliminating the need to balance all 4 ligaments. The development of modular tibial components has led to the availability of differing polyethylene inserts that permit adjustment to the flexion gap independent of the extension gap, permitting PCL balancing not previously available. The purpose of this study is to analyze a specific cruciate-retaining (CR) prosthesis which has 2 polyethylene inserts intended for CR knee use. Between February 2004 and February 2013, the senior author (R.H.E.) has performed 930 total knee arthroplasties using the CR flat insert and 424 knees using the CR lipped insert. The inserts were selected during surgery, based on the assessed tension and function of the PCL. The patients were followed up as part of a prospective total joint program with the Knee Society clinical scoring, range of motion, complications, revisions, preoperative coronal deformity, gender, body mass index, and status of the anterior-cruciate ligament intraoperatively. The average Knee Score was 92.4 for the flat group and 92.1 for the lipped group. Average knee flexion was 116.2° for the flat group and 114.4° for the lipped group (P=.2). Average knee extension (flexion deformity) was 2.1° for the flat group and 0.9° for the lipped group The results reported here show that clinical outcomes and survivorship were no different for either insert option, leading to indirect evidence that appropriate soft tissue balance had been achieved. Published by Elsevier Inc.

Effect of Reduced Stiffness Dance Flooring on Lower Extremity Joint Angular Trajectories During a Ballet Jump.

PubMed

Hackney, James; Brummel, Sara; Newman, Mary; Scott, Shannon; Reinagel, Matthew; Smith, Jennifer

2015-09-01

We carried out a study to investigate how low stiffness flooring may help prevent overuse injuries of the lower extremity in dancers. It was hypothesized that performing a ballet jump (sauté) on a reduced stiffness dance floor would decrease maximum joint flexion angles and negative angular velocities at the hips, knees, or ankles compared to performing the same jump on a harder floor. The participants were 15 young adult female dancers (age range 18 to 28, mean = 20.89 ± 2.93 years) with at least 5 years of continuous ballet experience and without history of serious lower body injury, surgery, or recent pain. They performed sautés on a (low stiffness) Harlequin ® WoodSpring Floor and on a vinyl-covered hardwood on concrete floor. Maximum joint flexion angles and negative velocities at bilateral hips, knees, and ankles were measured with the "Ariel Performance Analysis System" (APAS). Paired one-tailed t-tests yielded significant decreases in maximum knee angle (average decrease = 3.4° ± 4.2°, p = 0.026) and angular negative velocity of the ankles (average decrease = 18.7°/sec ± 27.9°/sec, p = 0.009) with low stiffness flooring. If the knee angle is less acute, then the length of the external knee flexion moment arm will also be shorter and result in a smaller external knee flexion moment, given an equal landing force. Also, high velocities of eccentric muscle contraction, which are necessary to control negative angular velocity of the ankle joint, are associated with higher risk of musculotendinous injury. Hence, our findings indicate that reduced floor stiffness may indeed help decrease the likelihood of lower extremity injuries.

Tibiofemoral Contact Forces in the Anterior Cruciate Ligament-Reconstructed Knee.

PubMed

Saxby, David John; Bryant, Adam L; Modenese, Luca; Gerus, Pauline; Killen, Bryce A; Konrath, Jason; Fortin, Karine; Wrigley, Tim V; Bennell, Kim L; Cicuttini, Flavia M; Vertullo, Christopher; Feller, Julian A; Whitehead, Tim; Gallie, Price; Lloyd, David G

2016-11-01

To investigate differences in anterior cruciate ligament-reconstructed (ACLR) and healthy individuals in terms of the magnitude of the tibiofemoral contact forces, as well as the relative muscle and external load contributions to those contact forces, during walking, running, and sidestepping gait tasks. A computational EMG-driven neuromusculoskeletal model was used to estimate the muscle and tibiofemoral contact forces in those with single-bundle combined semitendinosus and gracilis tendon autograft ACLR (n = 104, 29.7 ± 6.5 yr, 78.1 ± 14.4 kg) and healthy controls (n = 60, 27.5 ± 5.4 yr, 67.8 ± 14.0 kg) during walking (1.4 ± 0.2 m·s), running (4.5 ± 0.5 m·s) and sidestepping (3.7 ± 0.6 m·s). Within the computational model, the semitendinosus of ACLR participants was adjusted to account for literature reported strength deficits and morphological changes subsequent to autograft harvesting. ACLR had smaller maximum total and medial tibiofemoral contact forces (~80% of control values, scaled to bodyweight) during the different gait tasks. Compared with controls, ACLR were found to have a smaller maximum knee flexion moment, which explained the smaller tibiofemoral contact forces. Similarly, compared with controls, ACLR had both a smaller maximum knee flexion angle and knee flexion excursion during running and sidestepping, which may have concentrated the articular contact forces to smaller areas within the tibiofemoral joint. Mean relative muscle and external load contributions to the tibiofemoral contact forces were not significantly different between ACLR and controls. ACLR had lower bodyweight-scaled tibiofemoral contact forces during walking, running, and sidestepping, likely due to lower knee flexion moments and straighter knee during the different gait tasks. The relative contributions of muscles and external loads to the contact forces were equivalent between groups.

Weakening iliopsoas muscle in healthy adults may induce stiff knee pattern.

PubMed

Akalan, N Ekin; Kuchimov, Shavkat; Apti, Adnan; Temelli, Yener; Nene, Anand

2016-12-01

The goal of the present study was to investigate the relationship between iliopsoas muscle group weakness and related hip joint velocity reduction and stiff-knee gait (SKG) during walking in healthy individuals. A load of 5% of each individual's body weight was placed on non-dominant thigh of 15 neurologically intact, able-bodied participants (average age: 22.4 ± 0.81 years). For 33 min (135 s × 13 repetitions × 5 s rest), a passive stretch (PS) was applied with the load in place until hip flexor muscle strength dropped from 5/5 to 3+/5 according to manual muscle test. All participants underwent gait analysis before and after PS to compare sagittal plane hip, knee, and ankle kinematics and kinetics and temporo-spatial parameters. Paired t-test was used to compare pre- and post-stretch findings and Pearson correlation coefficient (r) was calculated to determine strength of correlation between SKG parameters and gait parameters of interest (p < 0.05). Reduced hip flexion velocity (mean: 21.5%; p = 0.005) was a contributor to SKG, decreasing peak knee flexion (PKF) (-20%; p = 0.0008), total knee range (-18.9%; p = 0.003), and range of knee flexion between toe-off and PKF (-26.7%; p = 0.001), and shortening duration between toe-off to PKF (-16.3%; p = 0.0005). These findings verify that any treatment protocol that slows hip flexion during gait by weakening iliopsoas muscle may have great potential to produce SKG pattern combined with reduced gait velocity. Copyright © 2016 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

Is latero-medial patellar mobility related to the range of motion of the knee joint after total knee arthroplasty?

PubMed

Ota, Susumu; Nakashima, Takeshi; Morisaka, Ayako; Omachi, Takaaki; Ida, Kunio; Kawamura, Morio

2010-12-01

Diminished range of motion (ROM) of the knee joint after total knee arthroplasty (TKA) is thought to be related to reduced patellar mobility. This has not been confirmed clinically due to a lack of quantitative methods adequate for measuring patellar mobility. We investigated the relationship between patellar mobility by a reported quantitative method and knee joint ROM after TKA. Forty-nine patients [osteoarthritis--OA: 29 knees; rheumatoid arthritis--RA: 20 knees] were examined after TKA. Respective medial and lateral patellar mobility was measured 1 and 6 months postoperatively using a patellofemoral arthrometer (PFA). Knee joint ROM was also measured in each of those 2 sessions. Although the flexion and extension of the knee joints improved significantly from 1 to 6 months after TKA, the medial and lateral patellar displacements (LPDs) failed to improve during that same period. Moreover, only the changes in knee flexion and medial patellar displacement (MPD) between the two sessions were positively correlated (r = 0.31, p < 0.05). However, our findings demonstrated that medial and lateral patellar mobility had no sufficient longitudinal relationship with knee ROM after TKA. Copyright © 2010 Elsevier Ltd. All rights reserved.

[Dynamic analysis in the knees with chronic anterior cruciate ligament insufficiency--an evaluation of antero-posterior instability, leg rotation and ground reaction force].

PubMed

Kanai, H

1993-07-01

A dynamic analysis was made on the knees with chronic anterior cruciate ligament (ACL) insufficiency for antero-posterior instability and abnormal rotation, also evaluating them for ground reaction force and muscle strength of knee extension. Studies were carried out on 51 patients with chronic unilateral ACL insufficiency and 80 knees of 40 healthy male and female young adults as controls. Using a knee motion analyser, an apparatus designed to analyse three dimensional knee motion, the gait was studied on a force plate. At the same time, the muscle strength of knee extension was measured with a Kinetic-Communicator (KIN-COM). In the dynamic analysis of the knee motion anterior instability was notable at a small angle of flexion. Qualitative evaluation of the knee motion revealed three patterns of rotation. The evaluation of ground reaction force showed that the rise from the heel strike was slow, its slope was gentle and the effect of weight removal was unclear. The evaluation of the muscle strength of knee extension revealed a decrease in torque of muscular contraction at 20 degrees of knee flexion.

Association between composites of selected motion palpation and pain provocation tests for sacroiliac joint disorders.

PubMed

Soleimanifar, Manijeh; Karimi, Noureddin; Arab, Amir Massoud

2017-04-01

The sacroiliac joint (SIJ) has been implicated as a potential source of low back and buttock pain. Several types of motion palpation and pain provocation tests are used to evaluate SIJ dysfunction. The purpose of this study was to investigate the relationship between motion palpation and pain provocation tests in assessment of SIJ problems. This study is Descriptive Correlation. 50 patients between the ages of 20 and 65 participated. Four motion palpation tests (Sitting flexion, Standing flexion, Prone knee flexion, Gillet test) and three pain provocation tests (FABER, Posterior shear, Resisted abduction test) were examined. Chi-square analysis was used to assess the relationship between results of the individuals and composites of these two groups of tests. No significant relationship was found between these two groups of tests. It seems that motion palpation tests assess SIJ dysfunction and provocative tests assessed SIJ pain which do not appear to be related. Copyright © 2016 Elsevier Ltd. All rights reserved.

Navigation-based femorotibial rotation pattern correlated with flexion angle after total knee arthroplasty.

PubMed

Ishida, Kazunari; Shibanuma, Nao; Matsumoto, Tomoyuki; Sasaki, Hiroshi; Takayama, Koji; Matsuzaki, Tokio; Tei, Katsumasa; Kuroda, Ryosuke; Kurosaka, Masahiro

2016-01-01

To investigate whether intraoperative kinematics obtained by navigation systems can be divided into several kinematic patterns and to assess the correlation between the intraoperative kinematics with maximum flexion angles before and after total knee arthroplasty (TKA). Fifty-four posterior-stabilised (PS) TKA implanted using an image-free navigation system were evaluated. At registration and after implantation, tibial internal rotation angles at maximum extension, 30°, 45°, 60°, 90°, and maximum flexion were collected. The rotational patterns were divided into four groups and were examined the correlation with maximum flexion before and after operation. Tibial internal rotation from 90° of flexion to maximum flexion at registration was correlated with maximum flexion angles pre- and postoperatively. The four groups showed statistically different kinematic patterns. The group with tibial external rotation up to 90° of flexion, following tibial internal rotation at registration, achieved better flexion angles, compared to those of another groups (126.7° ± 12.0°, p < 0.05). The group with tibial external rotation showed the worst flexion angles (80.0° ± 40.4°, p < 0.05). Furthermore, the group with limited extension showed worse flexion angles (111.6° ± 8.9°, p < 0.05). Navigation-based kinematic patterns found at registration predict postoperative maximum flexion angle in PS TKA. Navigation-based kinematics can be useful information during TKA surgery. Diagnostic studies, development of diagnostic criteria in a consecutive series of patients and a universally applied "gold" standard, Level II.

Rupture of posterior cruciate ligament leads to radial displacement of the medial meniscus.

PubMed

Zhang, Can; Deng, Zhenhan; Luo, Wei; Xiao, Wenfeng; Hu, Yihe; Liao, Zhan; Li, Kanghua; He, Hongbo

2017-07-11

To explore the association between the rupture of posterior cruciate ligament (PCL) and the radial displacement of medial meniscus under the conditions of different flexion and various axial loads. The radial displacement value of medial meniscus was measured for the specimens of normal adult knee joints, including 12 intact PCLs, 6 ruptures of the anterolateral bundle (ALB), 6 ruptures of the postmedial bundle (PMB), and 12 complete ruptures. The measurement was conducted at 0°, 30°, 60°, and 90° of knee flexion angles under 200 N, 400 N, 600 N, 800 N and 1000 N of axial loads respectively. The displacement values of medial meniscus of the ALB rupture group increased at 0° flexion under 800 N and 1000 N, and at 30°, 60° and 90° flexion under all loads in comparison with the PCL intact group. The displacement values of the PMB rupture group was higher at 0° and 90° flexion under all loads, and at 30° and 60° flexion under 800 N and 1000 N loads. The displacement of the PCL complete rupture group increased at all flexion angles under all loads. Either partial or complete rupture of the PCL can increase in the radial displacement of the medial meniscus, which may explain the degenerative changes that occuring in the medial meniscus due to PCL injury. Therefore, early reestablishment of the PCL is necessarily required in order to maintain stability of the knee joint after PCL injury.

Kinetic and kinematic differences between first and second landings of a drop vertical jump task: implications for injury risk assessments.

PubMed

Bates, Nathaniel A; Ford, Kevin R; Myer, Gregory D; Hewett, Timothy E

2013-04-01

Though the first landing of drop vertical jump task is commonly used to assess biomechanical performance measures that are associated with anterior cruciate ligament injury risk in athletes, the implications of the second landing in this task have largely been ignored. We examined the first and second landings of a drop vertical jump for differences in kinetic and kinematic behaviors at the hip and knee. A cohort of 239 adolescent female basketball athletes (age=13.6 (1.6) years) completed drop vertical jump tasks from an initial height of 31 cm. A three dimensional motion capture system recorded positional data while dual force platforms recorded ground reaction forces for each trial. The first landing demonstrated greater hip adduction angle, knee abduction angle, and knee abduction moment than the second landing (P-values<0.028). The second landing demonstrated smaller flexion angles and moments at the hip and knee than the first landing (P-values<0.035). The second landing also demonstrated greater side-to-side asymmetry in hip and knee kinematics and kinetics for both the frontal and sagittal planes (P-values<0.044). The results have important implications for the future use of the drop vertical jump as an assessment tool for anterior cruciate ligament injury risk behaviors in adolescent female athletes. The second landing may be a more rigorous task and provides a superior tool to evaluate sagittal plane risk factors than the first landing, which may be better suited to evaluate frontal plane risk factors. Copyright © 2013 Elsevier Ltd. All rights reserved.

Kinetic and kinematic differences between first and second landings of a drop vertical jump task: Implications for injury risk assessments✩

PubMed Central

Bates, Nathaniel A.; Ford, Kevin R.; Myer, Gregory D.; Hewett, Timothy E.

2013-01-01

Background Though the first landing of drop vertical jump task is commonly used to assess biomechanical performance measures that are associated with anterior cruciate ligament injury risk in athletes, the implications of the second landing in this task have largely been ignored. We examined the first and second landings of a drop vertical jump for differences in kinetic and kinematic behaviors at the hip and knee. Methods Acohort of 239 adolescent female basketball athletes (age = 13.6 (1.6) years) completed drop vertical jump tasks from an initial height of 31 cm. A three dimensional motion capture system recorded positional data while dual force platforms recorded ground reaction forces for each trial. Findings The first landing demonstrated greater hip adduction angle, knee abduction angle, and knee abduction moment than the second landing (P-values < 0.028). The second landing demonstrated smaller flexion angles and moments at the hip and knee than the first landing (P-values < 0.035). The second landing also demonstrated greater side-to-side asymmetry in hip and knee kinematics and kinetics for both the frontal and sagittal planes (P-values < 0.044). Interpretation The results have important implications for the future use of the drop vertical jump as an assessment tool for anterior cruciate ligament injury risk behaviors in adolescent female athletes. The second landing may be a more rigorous task and provides a superior tool to evaluate sagittal plane risk factors than the first landing, which may be better suited to evaluate frontal plane risk factors. PMID:23562293

Landing mechanics during single hop for distance in females following anterior cruciate ligament reconstruction compared to healthy controls.

PubMed

Trigsted, Stephanie M; Post, Eric G; Bell, David R

2017-05-01

To determine possible differences in single-hop kinematics and kinetics in females with anterior cruciate ligament reconstruction compared to healthy controls. A second purpose was to make comparisons between the healthy and reconstructed limbs. Subjects were grouped based on surgical status (33 ACLR patients and 31 healthy controls). 3D motion capture synchronized with force plates was used to capture the landing phase of three successful trials of single hop for distance during a single data collection session. Peak values during the loading phase were analysed. Subjects additionally completed three successful trials of the triple hop for distance Tegner activity scale and International Knee Document Committee 2000 (IKDC). Controls demonstrated greater peak knee flexion and greater internal knee extension moment and hip extension moment than ACLR subjects. Within the ACLR group, the healthy limb exhibited greater peak knee flexion, hip flexion, hip extension moment, single hop and triple hops for distance and normalized quadriceps strength. Patients who undergo anterior cruciate ligament reconstruction land in a more extended posture when compared to healthy controls and compared to their healthy limb. III.

Evaluation of the Length and Isometric Pattern of the Anterolateral Ligament With Serial Computer Tomography

PubMed Central

Helito, Camilo Partezani; Helito, Paulo Victor Partezani; Bonadio, Marcelo Batista; da Mota e Albuquerque, Roberto Freire; Bordalo-Rodrigues, Marcelo; Pecora, Jose Ricardo; Camanho, Gilberto Luis; Demange, Marco Kawamura

2014-01-01

Background: Recent anatomical studies have identified the anterolateral ligament (ALL). Injury to this structure may lead to the presence of residual pivot shift in some reconstructions of the anterior cruciate ligament. The behavior of the length of this structure and its tension during range of motion has not been established and is essential when planning reconstruction. Purpose: To establish differences in the ALL length during range of knee motion. Study Design: Descriptive laboratory study. Methods: Ten unpaired cadavers were dissected. The attachments of the ALL were isolated. Its origin and insertion were marked with a 2 mm–diameter metallic sphere. Computed tomography scans were performed on the dissected parts under extension and 30°, 60°, and 90° of flexion; measurements of the distance between the 2 markers were taken at all mentioned degrees of flexion. The distances between the points were compared. Results: The mean ALL length increased with knee flexion. Its mean length at full extension and at 30°, 60°, and 90° of flexion was 37.9 ± 5.3, 39.3 ± 5.4, 40.9 ± 5.4, and 44.1 ± 6.4 mm, respectively. The mean increase in length from 0° to 30° was 3.99% ± 4.7%, from 30° to 60° was 4.20% ± 3.2%, and from 60° to 90° was 7.45% ± 4.8%. From full extension to 90° of flexion, the ligament length increased on average 16.7% ± 12.1%. From 60° to 90° of flexion, there was a significantly higher increase in the mean distance between the points compared with the flexion from 0° to 30° and from 30° to 60°. Conclusion: The ALL shows no isometric behavior during the range of motion of the knee. The ALL increases in length from full extension to 90° of flexion by 16.7%, on average. The increase in length was greater from 60° to 90° than from 0° to 30° and from 30° to 60°. The increase in length at higher degrees of flexion suggests greater tension with increasing flexion. Clinical Relevance: Knowledge of ALL behavior during the range of motion of the knee will allow for fixation (during its reconstruction) to be performed with a higher or lower tension, depending on the chosen degree of flexion. PMID:26535292

Kinematics of ACL and anterolateral ligament. Part II: anterolateral and anterior cruciate ligament reconstruction.

PubMed

Bonanzinga, T; Signorelli, C; Grassi, A; Lopomo, N; Jain, M; Mosca, M; Iacono, F; Marcacci, M; Zaffagnini, S

2017-04-01

To quantify the influence of Single-Bundle with Lateral Plasty and Double-Bundle reconstruction on static and dynamic laxity in combined ACL- and ALL-deficient knees. The study included 10 fresh-frozen human knees. The joints were analyzed in the following conditions: ACL + ALL resection, Single-Bundle with Lateral Plasty (SBLP) reconstruction, Double-Bundle (DB) reconstruction. Testing parameters were: anterior displacement at 30° and 90° of flexion (AP30, AP90) applying a manual maximum load; internal rotation at 30° and 90° of flexion (INT30, INT90) applying a 5 Nm torque and acceleration and internal rotation Pivot-Shift (PS) test. Kinematics was acquired by a navigation system. Paired Student's t test was conducted to assess statistical difference (P < 0.05). At both 30° and 90° of knee flexion, both SBLP and DB surgical techniques showed a significant reduction (P < 0.01) of anterior-posterior tibial displacement compared to the resection of ACL + ALL. At 30° on knee flexion it is the SBLP that allows the greatest reduction of internal rotational laxity when compared to DB reconstruction. Concerning the PS test, only SBPL procedure had a significant laxity decrease considering the acceleration reached by the joint when compared with the ACL + ALL state (P < 0.01). Clinical relevance of this study is that the internal rotation and PS test were more efficiently controlled by the SBLP technique than by the DB one at both 30° and 90° of flexion in case of ACL + ALL lesions.

Phosphocreatine resynthesis during recovery in different muscles of the exercising leg by 31P-MRS.

PubMed

Yoshida, T; Abe, D; Fukuoka, Y

2013-10-01

To investigate the high-energy phosphate metabolism by (31) P-nuclear magnetic resonance spectroscopy during off-transition of exercise in different muscle groups, such as calf muscles and biceps femoris muscles, seven male long-distance runners (LDR) and nine untrained males (UT) performed both submaximal constant and incremental exercises. The relative exercise intensity was set at 60% of the maximal work rate (60%W max) during both knee flexion and plantar flexion submaximal constant load exercises. The relative areas under the inorganic phosphate (Pi ) and phosphocreatine (PCr) peaks were determined. During the 5-min recovery following the 60%W max, the time constant for the PCr off-kinetics was significantly faster in the plantar flexion (LDR: 17.3 ± 3.6 s, UT: 26.7 ± 6.7 s) than in the knee flexion (LDR: 29.7 ± 4.7 s, UT: 42.7 ± 2.8 s, P < 0.05). In addition, a significantly faster PCr off-kinetics was observed in LDR than in UT for both exercises. The ratio of Pi to PCr (Pi /PCr) during exercise was significantly lower during the plantar flexion than during the knee flexion (P < 0.01). These findings indicated that the calf muscles had relatively higher potential for oxidative capacity than that of biceps femoris muscles with an association of training status. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

How joint torques affect hamstring injury risk in sprinting swing-stance transition.

PubMed

Sun, Yuliang; Wei, Shutao; Zhong, Yunjian; Fu, Weijie; Li, Li; Liu, Yu

2015-02-01

The potential mechanisms of hamstring strain injuries in athletes are not well understood. The study, therefore, was aimed at understanding hamstring mechanics by studying loading conditions during maximum-effort overground sprinting. Three-dimensional kinematics and ground reaction force data were collected from eight elite male sprinters sprinting at their maximum effort. Maximal isometric torques of the hip and knee were also collected. Data from the sprinting gait cycle were analyzed via an intersegmental dynamics approach, and the different joint torque components were calculated. During the initial stance phase, the ground reaction force passed anteriorly to the knee and hip, producing an extension torque at the knee and a flexion torque at the hip joint. Thus, the active muscle torque functioned to produce flexion torque at the knee and extension torque at the hip. The maximal muscle torque at the knee joint was 1.4 times the maximal isometric knee flexion torque. During the late swing phase, the muscle torque counterbalanced the motion-dependent torque and acted to flex the knee joint and extend the hip joint. The loading conditions on the hamstring muscles were similar to those of the initial stance phase. During both the initial stance and late swing phases, the large passive torques at both the knee and hip joints acted to lengthen the hamstring muscles. The active muscle torques generated mainly by the hamstrings functioned to counteract those passive effects. As a result, during sprinting or high-speed locomotion, the hamstring muscles may be more susceptible to high risk of strain injury during these two phases.

Mid-term development of hamstring tendon length and velocity after distal femoral extension osteotomy in children with bilateral cerebral palsy: a retrospective cohort study.

PubMed

Salami, Firooz; Wagner, Julia; van Drongelen, Stefan; Klotz, Matthias C M; Dreher, Thomas; Wolf, Sebastian I; Niklasch, Mirjam

2018-03-14

Flexed knee gait can be treated with distal femoral extension osteotomy (DFEO) and additional patellar tendon advancement (PTA) in children with cerebral palsy (CP). This study assesses changes in hamstring muscle tendon length (MTL) and velocity after DFEO (+PTA). Nineteen children (mean age 13y [standard deviation 3y] at surgery) with CP and flexed knee gait who were treated with DFEO (15 limbs) or DFEO+PTA (10 limbs) were retrospectively included in this study. Gait analyses were performed preoperatively (E0), 1 year postoperatively (E1), and for 10 limbs additionally 2 to 5 years postoperatively (E2). Hamstring MTL and velocities were assessed at all examination dates using OpenSim. Hamstring MTL and velocity did not change significantly over time. From E0 to E1, knee flexion in stance improved for both DFEO and DFEO+PTA (p<0.05), knee flexion in swing only improved after DFEO+PTA (p<0.05). The improved knee flexion in stance and swing was maintained at E2. DFEO led to a significant improvement in knee kinematics at E1 which was maintained at E2. DFEO seems to prevent recurrent hamstring tightness but does not lead to lengthened or fastened hamstrings. Distal femoral extension osteotomy (DFEO) does not change hamstring muscle tendon length. DFEO does not change hamstring lengthening velocity. DFEO leads to a significant improvement in knee kinematics. Changes in knee kinematics after DFEO can be maintained at mid-term. DFEO seems to prevent recurrent hamstring tightness. © 2018 Mac Keith Press.

A study on muscle activity and ratio of the knee extensor depending on the types of squat exercise

PubMed Central

Kang, Jeong-Il; Park, Joon-Su; Choi, Hyun; Jeong, Dae-Keun; Kwon, Hye-Min; Moon, Young-Jun

2017-01-01

[Purpose] For preventing the patellofemoral pain syndrome, this study aims to suggest a proper squat method, which presents selective muscle activity of Vastus Medialis Oblique and muscle activity ratios of Vastus Medialis Oblique/Vastus Lateralis by applying squat that is a representative weight bearing exercise method in various ways depending on the surface conditions and knee bending angles. [Subjects and Methods] An isometric squat that was accompanied by hip adduction, depending on the surface condition and the knee joint flexion angle, was performed by 24 healthy students. The muscle activity and the ratio of muscle activity were measured. [Results] In a comparison of muscle activity depending on the knee joint flexion angle on a weight-bearing surface, the vastus medialis oblique showed a significant difference at 15° and 60°. Meanwhile, in a comparison of the muscle activity ratio between the vastus medialis oblique and the vastus lateralis depending on the knee joint flexion angle on a weight-bearing surface, significant differences were observed at 15° and 60°. [Conclusion] An efficient squat exercise posture for preventing the patellofemoral pain syndrome is to increase the knee joint bending angle on a stable surface. But it would be efficient for patients with difficulties in bending the knee joint to keep a knee joint bending angle of 15 degrees or less on an unstable surface. It is considered that in future, diverse studies on selective Vastus Medialis Oblique strengthening exercise methods would be needed after applying them to patients with the patellofemoral pain syndrome. PMID:28210036

Core strength and lower extremity alignment during single leg squats.

PubMed

Willson, John D; Ireland, Mary Lloyd; Davis, Irene

2006-05-01

Muscles of the trunk, hip, and knee influence the orientation of the lower extremity during weight bearing activities. The purpose of this study was threefold: first, to compare the orientation of the lower extremity during a single leg (SL) squat among male and female athletes; second, to compare the strength of muscle groups in the trunk, hips, and knees between these individuals; and third, to evaluate the association between trunk, hip, and knee strength and the orientation of the knee joint during this activity. Twenty-four male and 22 female athletes participated in this study. Peak isometric torque was determined for the following muscle actions: trunk flexion, extension, and lateral flexion, hip abduction and external rotation, and knee flexion and extension. The frontal plane projection angle (FPPA) of the knee during a 45 degrees SL squat was determined using photo editing software. Males and females moved in opposite directions during the SL squat test (F(1,42) = 5.05, P = 0.03). Females typically moved toward more extreme FPPA during SL squats (P = 0.056), while males tended to move toward more neutral alignment (P = 0.066). Females also generated less torque in all muscle groups, with the exception of trunk extension. The projection angle of the knee during the SL squat test was most closely associated with hip external rotation strength. Using instruments suitable for a clinical setting, females were found to have greater FPPA and generally decreased trunk, hip, and knee isometric torque. Hip external rotation strength was most closely associated with the frontal plane projection angle.

How Joint Torques Affect Hamstring Injury Risk in Sprinting Swing–Stance Transition

PubMed Central

SUN, YULIANG; WEI, SHUTAO; ZHONG, YUNJIAN; FU, WEIJIE; LI, LI; LIU, YU

2015-01-01

ABSTRACT Purpose The potential mechanisms of hamstring strain injuries in athletes are not well understood. The study, therefore, was aimed at understanding hamstring mechanics by studying loading conditions during maximum-effort overground sprinting. Methods Three-dimensional kinematics and ground reaction force data were collected from eight elite male sprinters sprinting at their maximum effort. Maximal isometric torques of the hip and knee were also collected. Data from the sprinting gait cycle were analyzed via an intersegmental dynamics approach, and the different joint torque components were calculated. Results During the initial stance phase, the ground reaction force passed anteriorly to the knee and hip, producing an extension torque at the knee and a flexion torque at the hip joint. Thus, the active muscle torque functioned to produce flexion torque at the knee and extension torque at the hip. The maximal muscle torque at the knee joint was 1.4 times the maximal isometric knee flexion torque. During the late swing phase, the muscle torque counterbalanced the motion-dependent torque and acted to flex the knee joint and extend the hip joint. The loading conditions on the hamstring muscles were similar to those of the initial stance phase. Conclusions During both the initial stance and late swing phases, the large passive torques at both the knee and hip joints acted to lengthen the hamstring muscles. The active muscle torques generated mainly by the hamstrings functioned to counteract those passive effects. As a result, during sprinting or high-speed locomotion, the hamstring muscles may be more susceptible to high risk of strain injury during these two phases. PMID:24911288

How exactly can computer simulation predict the kinematics and contact status after TKA? Examination in individualized models.

PubMed

Tanaka, Yoshihisa; Nakamura, Shinichiro; Kuriyama, Shinichi; Ito, Hiromu; Furu, Moritoshi; Komistek, Richard D; Matsuda, Shuichi

2016-11-01

It is unknown whether a computer simulation with simple models can estimate individual in vivo knee kinematics, although some complex models have predicted the knee kinematics. The purposes of this study are first, to validate the accuracy of the computer simulation with our developed model during a squatting activity in a weight-bearing deep knee bend and then, to analyze the contact area and the contact stress of the tri-condylar implants for individual patients. We compared the anteroposterior (AP) contact positions of medial and lateral condyles calculated by the computer simulation program with the positions measured from the fluoroscopic analysis for three implanted knees. Then the contact area and the stress including the third condyle were calculated individually using finite element (FE) analysis. The motion patterns were similar in the simulation program and the fluoroscopic surveillance. Our developed model could nearly estimate the individual in vivo knee kinematics. The mean and maximum differences of the AP contact positions were 1.0mm and 2.5mm, respectively. At 120° of knee flexion, the contact area at the third condyle was wider than the both condyles. The mean maximum contact stress at the third condyle was lower than the both condyles at 90° and 120° of knee flexion. Individual bone models are required to estimate in vivo knee kinematics in our simple model. The tri-condylar implant seems to be safe for deep flexion activities due to the wide contact area and low contact stress. Copyright © 2016 Elsevier Ltd. All rights reserved.

Non-invasive quantification of lower limb mechanical alignment in flexion

PubMed Central

Deakin, Angela; Fogg, Quentin A.; Picard, Frederic

2014-01-01

Objective Non-invasive navigation techniques have recently been developed to determine mechanical femorotibial alignment (MFTA) in extension. The primary aim of this study was to evaluate the precision and accuracy of an image-free navigation system with new software designed to provide multiple kinematic measurements of the knee. The secondary aim was to test two types of strap material used to attach optical trackers to the lower limb. Methods Seventy-two registrations were carried out on 6 intact embalmed cadaveric specimens (mean age: 77.8 ± 12 years). A validated fabric strap, bone screws and novel rubber strap were used to secure the passive tracker baseplate for four full experiments with each knee. The MFTA angle was measured under the conditions of no applied stress, valgus stress, and varus stress. These measurements were carried out at full extension and at 30°, 40°, 50° and 60° of flexion. Intraclass correlation coefficients, repeatability coefficients, and limits of agreement (LOA) were used to convey precision and agreement in measuring MFTA with respect to each of the independent variables, i.e., degree of flexion, applied coronal stress, and method of tracker fixation. Based on the current literature, a repeatability coefficient and LOA of ≤3° were deemed acceptable. Results The mean fixed flexion for the 6 specimens was 12.8° (range: 6–20°). The mean repeatability coefficient measuring MFTA in extension with screws or fabric strapping of the baseplate was ≤2°, compared to 2.3° using rubber strapping. When flexing the knee, MFTA measurements taken using screws or fabric straps remained precise (repeatability coefficient ≤3°) throughout the tested range of flexion (12.8–60°); however, using rubber straps, the repeatability coefficient was >3° beyond 50° flexion. In general, applying a varus/valgus stress while measuring MFTA decreased precision beyond 40° flexion. Using fabric strapping, excellent repeatability (coefficient ≤2°) was observed until 40° flexion; however, beyond 50° flexion, the repeatability coefficient was >3°. As was the case with precision, agreement between the invasive and non-invasive systems was satisfactory in extension and worsened with flexion. Mean limits of agreement between the invasive and non-invasive system using fabric strapping to assess MFTA were 3° (range: 2.3–3.8°) with no stress applied and 3.9° (range: 2.8–5.2°) with varus and valgus stress. Using rubber strapping, the corresponding values were 4.4° (range: 2.8–8.5°) with no stress applied, 5.5° (range: 3.3–9.0°) with varus stress, and 5.6° (range: 3.3–11.9°) with valgus stress. Discussion Acceptable precision and accuracy may be possible when measuring knee kinematics in early flexion using a non-invasive system; however, we do not believe passive trackers should be mounted with rubber strapping such as was used in this study. Flexing the knee appears to decrease the precision and accuracy of the system. The functions of this new software using image-free navigation technology have many potential clinical applications, including assessment of bony and soft tissue deformity, pre-operative planning, and post-operative evaluation, as well as in further pure research comparing kinematics of the normal and pathological knee. PMID:24856249

High incidence of loosening of the femoral component in legacy posterior stabilised-flex total knee replacement.

PubMed

Han, H S; Kang, S-B; Yoon, K S

2007-11-01

We have examined the results obtained with 72 NexGen legacy posterior stabilised-flex fixed total knee replacements in 47 patients implanted by a single surgeon between March 2003 and September 2004. Aseptic loosening of the femoral component was found in 27 (38%) of the replacements at a mean follow-up of 32 months (30 to 48) and 15 knees (21%) required revision at a mean of 23 months (11 to 45). We compared the radiologically-loose and revised knees with those which had remained well-fixed to identify the factors which had contributed to this high rate of aseptic loosening. Post-operatively, the mean maximum flexion was 136 degrees (110 degrees to 140 degrees) in the loosened group and 125 degrees (95 degrees to 140 degrees) in the well-fixed group (independent t-test, p = 0.022). Squatting, kneeling, or sitting cross-legged could be achieved by 23 (85%) of the loosened knees, but only 22 (49%) of the well-fixed knees (chi-squared test, p = 0.001). The loosened femoral components were found to migrate into a more flexed position, but no migration was detected in the well-fixed group. These implants allowed a high degree of flexion, but showed a marked rate of early loosening of the femoral component, which was associated with weight-bearing in maximum flexion.

Kinematic analysis of anterior cruciate ligament reconstruction in total knee arthroplasty

PubMed Central

Liu, Hua-Wei; Ni, Ming; Zhang, Guo-Qiang; Li, Xiang; Chen, Hui; Zhang, Qiang; Chai, Wei; Zhou, Yong-Gang; Chen, Ji-Ying; Liu, Yu-Liang; Cheng, Cheng-Kung; Wang, Yan

2016-01-01

Background: This study aims to retain normal knee kinematics after knee replacement surgeries by reconstructing anterior cruciate ligament during total knee arthroplasty. Method: We use computational simulation tools to establish four dynamic knee models, including normal knee model, posterior cruciate ligament retaining knee model, posterior cruciate ligament substituting knee model, and anterior cruciate ligament reconstructing knee model. Our proposed method utilizes magnetic resonance images to reconstruct solid bones and attachments of ligaments, and assemble femoral and tibial components according representative literatures and operational specifications. Dynamic data of axial tibial rotation and femoral translation from full-extension to 135 were measured for analyzing the motion of knee models. Findings: The computational simulation results show that comparing with the posterior cruciate ligament retained knee model and the posterior cruciate ligament substituted knee model, reconstructing anterior cruciate ligament improves the posterior movement of the lateral condyle, medial condyle and tibial internal rotation through a full range of flexion. The maximum posterior translations of the lateral condyle, medial condyle and tibial internal rotation of the anterior cruciate ligament reconstructed knee are 15.3 mm, 4.6 mm and 20.6 at 135 of flexion. Interpretation: Reconstructing anterior cruciate ligament in total knee arthroplasty has been approved to be an more efficient way of maintaining normal knee kinematics comparing to posterior cruciate ligament retained and posterior cruciate ligament substituted total knee arthroplasty. PMID:27347334

Joint angle affects volitional and magnetically-evoked neuromuscular performance differentially.

PubMed

Minshull, C; Rees, D; Gleeson, N P

2011-08-01

This study examined the volitional and magnetically-evoked neuromuscular performance of the quadriceps femoris at functional knee joint angles adjacent to full extension. Indices of volitional and magnetically-evoked neuromuscular performance (N=15 healthy males, 23.5 ± 2.9 years, 71.5 ± 5.4 kg, 176.5 ± 5.5 cm) were obtained at 25°, 35° and 45° of knee flexion. Results showed that volitional and magnetically-evoked peak force (PF(V) and P(T)F(E), respectively) and electromechanical delay (EMD(V) and EMD(E), respectively) were enhanced by increased knee flexion. However, greater relative improvements in volitional compared to evoked indices of neuromuscular performance were observed with increasing flexion from 25° to 45° (e.g. EMD(V), EMD(E): 36% vs. 11% improvement, respectively; F([2,14])=6.8, p<0.05). There were no significant correlations between EMD(V) and EMD(E) or PF(V) and P(T)F(E), at analogous joint positions. These findings suggest that the extent of the relative differential between volitional and evoked neuromuscular performance capabilities is joint angle-specific and not correlated with performance capabilities at adjacent angles, but tends to be smaller with increased flexion. As such, effective prediction of volitional from evoked performance capabilities at both analogous and adjacent knee joint positions would lack robustness. Copyright © 2011 Elsevier Ltd. All rights reserved.

A flexible wearable sensor for knee flexion assessment during gait.

PubMed

Papi, Enrica; Bo, Yen Nee; McGregor, Alison H

2018-05-01

Gait analysis plays an important role in the diagnosis and management of patients with movement disorders but it is usually performed within a laboratory. Recently interest has shifted towards the possibility of conducting gait assessments in everyday environments thus facilitating long-term monitoring. This is possible by using wearable technologies rather than laboratory based equipment. This study aims to validate a novel wearable sensor system's ability to measure peak knee sagittal angles during gait. The proposed system comprises a flexible conductive polymer unit interfaced with a wireless acquisition node attached over the knee on a pair of leggings. Sixteen healthy volunteers participated to two gait assessments on separate occasions. Data was simultaneously collected from the novel sensor and a gold standard 10 camera motion capture system. The relationship between sensor signal and reference knee flexion angles was defined for each subject to allow the transformation of sensor voltage outputs to angular measures (degrees). The knee peak flexion angle from the sensor and reference system were compared by means of root mean square error (RMSE), absolute error, Bland-Altman plots and intra-class correlation coefficients (ICCs) to assess test-retest reliability. Comparisons of knee peak flexion angles calculated from the sensor and gold standard yielded an absolute error of 0.35(±2.9°) and RMSE of 1.2(±0.4)°. Good agreement was found between the two systems with the majority of data lying within the limits of agreement. The sensor demonstrated high test-retest reliability (ICCs>0.8). These results show the ability of the sensor to monitor knee peak sagittal angles with small margins of error and in agreement with the gold standard system. The sensor has potential to be used in clinical settings as a discreet, unobtrusive wearable device allowing for long-term gait analysis. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Dynamic augmentation restores anterior tibial translation in ACL suture repair: a biomechanical comparison of non-, static and dynamic augmentation techniques.

PubMed

Hoogeslag, Roy A G; Brouwer, Reinoud W; Huis In 't Veld, Rianne; Stephen, Joanna M; Amis, Andrew A

2018-02-03

There is a lack of objective evidence investigating how previous non-augmented ACL suture repair techniques and contemporary augmentation techniques in ACL suture repair restrain anterior tibial translation (ATT) across the arc of flexion, and after cyclic loading of the knee. The purpose of this work was to test the null hypotheses that there would be no statistically significant difference in ATT after non-, static- and dynamic-augmented ACL suture repair, and they will not restore ATT to normal values across the arc of flexion of the knee after cyclic loading. Eleven human cadaveric knees were mounted in a test rig, and knee kinematics from 0° to 90° of flexion were recorded by use of an optical tracking system. Measurements were recorded without load and with 89-N tibial anterior force. The knees were tested in the following states: ACL-intact, ACL-deficient, non-augmented suture repair, static tape augmentation and dynamic augmentation after 10 and 300 loading cycles. Only static tape augmentation and dynamic augmentation restored ATT to values similar to the ACL-intact state directly postoperation, and maintained this after cyclic loading. However, contrary to dynamic augmentation, the ATT after static tape augmentation failed to remain statistically less than for the ACL-deficient state after cyclic loading. Moreover, after cyclic loading, ATT was significantly less with dynamic augmentation when compared to static tape augmentation. In contrast to non-augmented ACL suture repair and static tape augmentation, only dynamic augmentation resulted in restoration of ATT values similar to the ACL-intact knee and decreased ATT values when compared to the ACL-deficient knee immediately post-operation and also after cyclic loading, across the arc of flexion, thus allowing the null hypotheses to be rejected. This may assist healing of the ruptured ACL. Therefore, this study would support further clinical evaluation of dynamic augmentation of ACL repair.

Towards understanding knee joint laxity: errors in non-invasive assessment of joint rotation can be corrected.

PubMed

Moewis, P; Boeth, H; Heller, M O; Yntema, C; Jung, T; Doyscher, R; Ehrig, R M; Zhong, Y; Taylor, W R

2014-07-01

The in vivo quantification of rotational laxity of the knee joint is of importance for monitoring changes in joint stability or the outcome of therapies. While invasive assessments have been used to study rotational laxity, non-invasive methods are attractive particularly for assessing young cohorts. This study aimed to determine the conditions under which tibio-femoral rotational laxity can be assessed reliably and accurately in a non-invasive manner. The reliability and error of non-invasive examinations of rotational joint laxity were determined by comparing the artefact associated with surface mounted markers against simultaneous measurements using fluoroscopy in five knees including healthy and ACL deficient joints. The knees were examined at 0°, 30°, 60° and 90° flexion using a device that allows manual axial rotation of the joint. With a mean RMS error of 9.6°, the largest inaccuracy using non-invasive assessment was present at 0° knee flexion, whereas at 90° knee flexion, a smaller RMS error of 5.7° was found. A Bland and Altman assessment indicated that a proportional bias exists between the non-invasive and fluoroscopic approaches, with limits of agreement that exceeded 20°. Correction using average linear regression functions resulted in a reduction of the RMS error to below 1° and limits of agreement to less than ±1° across all knees and flexion angles. Given the excellent reliability and the fact that a correction of the surface mounted marker based rotation values can be achieved, non-invasive evaluation of tibio-femoral rotation could offer opportunities for simplified devices for use in clinical settings in cases where invasive assessments are not justified. Although surface mounted marker based measurements tend to overestimate joint rotation, and therefore joint laxity, our results indicate that it is possible to correct for this error. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

Decreased flexion contracture after total knee arthroplasty using Botulinum toxin A: a randomized controlled trial.

PubMed

Smith, Eric B; Shafi, Karim A; Greis, Ari C; Maltenfort, Mitchell G; Chen, Antonia F

2016-10-01

Flexion contracture after total knee arthroplasty (TKA) can cause significant dissatisfaction. Botulinum toxin A has shown improved extension in patients with spastic flexion contractures after TKA. The purpose of this study was to evaluate whether Botulinum toxin A improves knee extension for any patient with flexion contractures following TKA. A prospective, double-blinded, randomized controlled trial was conducted. Fourteen patients (15 knees), with a flexion contracture (≥10°) one month postoperatively, were randomized to receive either Botulinum toxin A or saline placebo to the affected hamstrings. The subject, surgeon, and administering physiatrist were blinded to the treatment group throughout the study. Subject range of motion (ROM) was evaluated at 1, 6, and 12 months following injection. Differences were tested using mixed-effects regression to control for multiple measurements. The initial post-operative flexion contracture averaged 19° ± 6° in the Botulinum toxin A group and 13° ± 3° in the saline group. Injections were performed 53 and 57 days after TKA in the Botulinum toxin A and saline groups, respectively. Post-injection extension improved to an average of 8, 5, and 1 degrees for BTX and 4, 2, and 1 degrees for SAL, at 1, 6, and 12 months, respectively, compared to pre-injection extension (p < 0.0001). Improvement in knee extension at 1 year improved 18° ± 7.5° for Botulinum toxin A and 12° ± 2° for saline (p = 0.04). No complications resulted from either injection. Patients who received Botulinum toxin A or placebo were able to achieve near full extension one year after surgery. There was a statistically significant improvement in the amount of extension achieved at 1 year with Botulinum toxin A, but this may be of little clinical significance. Since achieving full extension is important for patient function and satisfaction, novel techniques to address this issue deserve special attention. I.

Hydraulic distension of the knee: a novel treatment for arthrofibrosis after total knee replacement (case series).

PubMed

Formby, Peter M; Donohue, Michael A; Cannova, Christopher J; Caulfield, J Patrick

2016-06-01

Arthrofibrosis following total knee arthroplasty (TKA) is a common problem, which can be frustrating to both the patient and treating physician and can dramatically compromise post-operative function. Current treatment options for TKA arthrofibrosis include watchful waiting, injections, physical therapy, manipulation under anaesthesia, arthroscopic/open lysis of adhesions and revision surgery. We present a novel technique to treat acute and chronic stiffness following TKA, which we call hydraulic distension. A retrospective pre- and post-operative inpatient and outpatient record review of three patients treated with hydraulic distension for arthrofibrosis following TKA at a single institution. Three patients with a mean age of 74 years (68-78) underwent hydraulic distension of the knee at a mean of 23.4 ± 18.4 months (9 weeks to 36 months) following primary TKA. The mean pre-distension maximum flexion was 86.7 ± 10.4°, and the mean post-distension flexion was 110 ± 13.2° (23.3° increase). The patients maintained a mean 110 ± 20° flexion (23.3° increase) at a mean follow-up of 11.7 months (1 week to 29 months). There were no complications. We present a novel technique for managing arthrofibrosis following TKA that has not been previously reported. This is an effective, safe procedure, with our patients experiencing a mean 23° increased knee flexion at the most recent follow-up. Published 2016. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Role of central command in carotid baroreflex resetting in humans during static exercise

NASA Technical Reports Server (NTRS)

Ogoh, S.; Wasmund, W. L.; Keller, D. M.; O-Yurvati, A.; Gallagher, K. M.; Mitchell, J. H.; Raven, P. B.

2002-01-01

The purpose of the experiments was to examine the role of central command in the exercise-induced resetting of the carotid baroreflex. Eight subjects performed 30 % maximal voluntary contraction (MVC) static knee extension and flexion with manipulation of central command (CC) by patellar tendon vibration (PTV). The same subjects also performed static knee extension and flexion exercise without PTV at a force development that elicited the same ratings of perceived exertion (RPE) as those observed during exercise with PTV in order to assess involvement of the exercise pressor reflex. Carotid baroreflex (CBR) function curves were modelled from the heart rate (HR) and mean arterial pressure (MAP) responses to rapid changes in neck pressure and suction during steady state static exercise. Knee extension exercise with PTV (decreased CC activation) reset the CBR-HR and CBR-MAP to a lower operating pressure (P < 0.05) and knee flexion exercise with PTV (increased CC activation) reset the CBR-HR and CBR-MAP to a higher operating pressure (P < 0.05). Comparison between knee extension and flexion exercise at the same RPE with and without PTV found no difference in the resetting of the CBR-HR function curves (P > 0.05) suggesting the response was determined primarily by CC activation. However, the CBR-MAP function curves were reset to operating pressures determined by both exercise pressor reflex (EPR) and central command activation. Thus the physiological response to exercise requires CC activation to reset the carotid-cardiac reflex but requires either CC or EPR to reset the carotid-vasomotor reflex.

Muscle strength and knee range of motion after femoral lengthening.

PubMed

Bhave, Anil; Shabtai, Lior; Woelber, Erik; Apelyan, Arman; Paley, Dror; Herzenberg, John E

2017-04-01

Background and purpose - Femoral lengthening may result in decrease in knee range of motion (ROM) and quadriceps and hamstring muscle weakness. We evaluated preoperative and postoperative knee ROM, hamstring muscle strength, and quadriceps muscle strength in a diverse group of patients undergoing femoral lengthening. We hypothesized that lengthening would not result in a significant change in knee ROM or muscle strength. Patients and methods - This prospective study of 48 patients (mean age 27 (9-60) years) compared ROM and muscle strength before and after femoral lengthening. Patient age, amount of lengthening, percent lengthening, level of osteotomy, fixation time, and method of lengthening were also evaluated regarding knee ROM and strength. The average length of follow-up was 2.9 (2.0-4.7) years. Results - Mean amount of lengthening was 5.2 (2.4-11.0) cm. The difference between preoperative and final knee flexion ROM was 2° for the overall group. Congenital shortening cases lost an average of 5% or 6° of terminal knee flexion, developmental cases lost an average of 3% or 4°, and posttraumatic cases regained all motion. The difference in quadriceps strength at 45° preoperatively and after lengthening was not statistically or clinically significant (2.7 Nm; p = 0.06). Age, amount of lengthening, percent lengthening, osteotomy level, fixation time, and lengthening method had no statistically significant influence on knee ROM or quadriceps strength at final follow-up. Interpretation - Most variables had no effect on ROM or strength, and higher age did not appear to be a limiting factor for femoral lengthening. Patients with congenital causes were most affected in terms of knee flexion.

Effects of physiotherapy treatment on knee osteoarthritis gait data using principal component analysis.

PubMed

Gaudreault, Nathaly; Mezghani, Neila; Turcot, Katia; Hagemeister, Nicola; Boivin, Karine; de Guise, Jacques A

2011-03-01

Interpreting gait data is challenging due to intersubject variability observed in the gait pattern of both normal and pathological populations. The objective of this study was to investigate the impact of using principal component analysis for grouping knee osteoarthritis (OA) patients' gait data in more homogeneous groups when studying the effect of a physiotherapy treatment. Three-dimensional (3D) knee kinematic and kinetic data were recorded during the gait of 29 participants diagnosed with knee OA before and after they received 12 weeks of physiotherapy treatment. Principal component analysis was applied to extract groups of knee flexion/extension, adduction/abduction and internal/external rotation angle and moment data. The treatment's effect on parameters of interest was assessed using paired t-tests performed before and after grouping the knee kinematic data. Increased quadriceps and hamstring strength was observed following treatment (P<0.05). Except for the knee flexion/extension angle, two different groups (G(1) and G(2)) were extracted from the angle and moment data. When pre- and post-treatment analyses were performed considering the groups, participants exhibiting a G(2) knee moment pattern demonstrated a greater first peak flexion moment, lower adduction moment impulse and smaller rotation angle range post-treatment (P<0.05). When pre- and post-treatment comparisons were performed without grouping, the data showed no treatment effect. The results of the present study suggest that the effect of physiotherapy on gait mechanics of knee osteoarthritis patients may be masked or underestimated if kinematic data are not separated into more homogeneous groups when performing pre- and post-treatment comparisons. Copyright © 2010 Elsevier Ltd. All rights reserved.

Knee kinematics and joint moments during gait following anterior cruciate ligament reconstruction: a systematic review and meta-analysis.

PubMed

Hart, Harvi F; Culvenor, Adam G; Collins, Natalie J; Ackland, David C; Cowan, Sallie M; Machotka, Zuzana; Crossley, Kay M

2016-05-01

Abnormal gait after anterior cruciate ligament reconstruction (ACLR) may contribute to development and/or progression of knee osteoarthritis. To conduct a systematic review and meta-analysis of knee kinematics and joint moments during walking after ACLR. We searched seven electronic databases and reference lists of relevant papers, for cross-sectional, human-based observational studies comparing knee joint kinematics and moments during level walking in individuals with ACLR, with the uninjured contralateral knee or healthy individuals as a control. Two independent reviewers appraised methodological quality (modified Downs and Black scale). Where possible, data were pooled by time post-ACLR (RevMan), otherwise narrative synthesis was undertaken. Thirty-four studies were included. Meta-analysis revealed significant sagittal plane deficits in ACLR knees. We found greater knee flexion angles (standardised mean difference: 1.06; 95% CI 0.39 to 1.74) and joint moments (1.61; 0.87 to 2.35) <6 months post-ACLR, compared to healthy controls. However, lower peak knee flexion angles were identified 1-3 years (-2.21; -3.16 to -1.26) and ≥3 years post-ACLR (-1.38, -2.14 to -0.62), and lower knee flexion moment 6-12 months post-ACLR (-0.76; -1.40 to -0.12). Pooled data provided strong evidence of no difference in peak knee adduction moment >3 years after ACLR (vs healthy controls) (0.09; -0.63 to 0.81). No transverse plane conclusions could be drawn. Sagittal plane biomechanics, rather than the knee adduction moment, appear to be more relevant post-ACLR. Better understanding of sagittal plane biomechanics is necessary for optimal post-operative recovery, and to potentially prevent early onset and progression of knee OA after ACLR. PROSPERO systematic review protocol registration number CRD4201400882 2. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

[Restricted motion after total knee arthroplasty].

PubMed

Kucera, T; Urban, K; Karpas, K; Sponer, P

2007-10-01

The aim of the study was to ascertain what proportion of patients undergoing total knee arthroplasty (TKA) complain of restricted knee joint motion, and to investigate options for improvement of this situation. Our evaluation included a group of 796 patients treated with TKA at our department in the period from January 1, 1990, to December 31, 2004. In all cases, a condylar implant with preservation of the posterior cruciate ligaments was used. In addition to medical history, the range of motion, knee joint malalignment and radiological findings were assessed before surgery. After THA, the type of implant and complications, if any, were recorded, and improvement in joint motion was followed up. Based on the results of Kim et al., flexion contracture equal to or higher than 15 degrees and/or flexion less than 75 degrees were made the criteria of stiffness after THA. Patients with restricted THA motion who had aseptic or septic implant loosening were not included. Of the 796 evaluated patients, 32 (4.14 %) showed restricted motion after total knee arthroplasty, as assessed by the established criteria. In 16 patients, stiffness defined by these criteria had existed before surgery, and three patients showed an excessive production of adhesions and heterotopic ossifications. In three patients, the implantation procedure resulted in an elevated level of the original joint line and subsequent development of patella infera and increased tension of the posterior cruciate ligament. Four patients declined physical therapy and, in six, the main cause of stiffness could not be found. Seventeen patients did not require surgical therapy for restricted motion; TKA provided significant pain relief and they considered the range of motion achieved to be sufficient. One patient underwent redress 3 months after surgery, but with no success. Repeated releases of adhesions, replacement of a polyethylene liner and revision surgery of the extensor knee structures were performed in 15 patients. In these, the average value of knee flexion increased by 17 degrees only and, in the patients suffering from excessive adhesion production, this value remained almost unchanged. Revision TKA was carried out in four patients, in whom knee joint flexion increased on average by 35 degrees to achieve an average flexion of 83 degrees. Restricted motion after TKA has been reported to range from 1.3 % to 12.0 %, but consistent criteria have not been set up. In our study it was 4.14 %. In agreement with the literature data, one of the reasons was pre-operative restricted motion, which was recorded in 16 of 32 patients. Similarly, also in our patients, biological predisposition to excessive production of fibrocartilage associated with adhesions in all knee joint compartments was the major therapeutic problem. Intra-operative fractures, ligament tears requiring post-operative fixation and unremoved dorsal osteophytes lead to the restriction of knee joint motion. By inadequate resection of articular surface, the original joint line may be at a higher level; this results in an increased tension of the posterior cruciate ligament and patella infera development, both influencing knee flexion. In our study, three patients were affected. Knee joint stiffness can also develop in patients declining physical therapy or in whom this is not correctly performed, often for insufficient analgesia. In contrast to the data reported in the literature, 17 of 32 patients in this study had no need for surgical treatment of restricted knee joint motion. Redress under general anesthesia was not effective. For markedly restricted motion of the knee joint, reimplantation can be recommended or, in less severe cases, an intervention on adjacent soft tissues. Restricted motion of the knee joint after TKA is difficult to treat and, therefore, prevention is recommended. This should include thorough conservative treatment of gonarthrosis, early indication for surgery, prevention of elevation in the joint line and consistent rehabilitation with appropriate analgesia. For severe stiffness of the knee joint, as evaluated by the criteria of Kim et al., revision arthroplasty can be recommended.

Femoral Component External Rotation Affects Knee Biomechanics: A Computational Model of Posterior-stabilized TKA.

PubMed

Kia, Mohammad; Wright, Timothy M; Cross, Michael B; Mayman, David J; Pearle, Andrew D; Sculco, Peter K; Westrich, Geoffrey H; Imhauser, Carl W

2018-01-01

The correct amount of external rotation of the femoral component during TKA is controversial because the resulting changes in biomechanical knee function associated with varying degrees of femoral component rotation are not well understood. We addressed this question using a computational model, which allowed us to isolate the biomechanical impact of geometric factors including bony shapes, location of ligament insertions, and implant size across three different knees after posterior-stabilized (PS) TKA. Using a computational model of the tibiofemoral joint, we asked: (1) Does external rotation unload the medial collateral ligament (MCL) and what is the effect on lateral collateral ligament tension? (2) How does external rotation alter tibiofemoral contact loads and kinematics? (3) Does 3° external rotation relative to the posterior condylar axis align the component to the surgical transepicondylar axis (sTEA) and what anatomic factors of the femoral condyle explain variations in maximum MCL tension among knees? We incorporated a PS TKA into a previously developed computational knee model applied to three neutrally aligned, nonarthritic, male cadaveric knees. The computational knee model was previously shown to corroborate coupled motions and ligament loading patterns of the native knee through a range of flexion. Implant geometries were virtually installed using hip-to-ankle CT scans through measured resection and anterior referencing surgical techniques. Collateral ligament properties were standardized across each knee model by defining stiffness and slack lengths based on the healthy population. The femoral component was externally rotated from 0° to 9° relative to the posterior condylar axis in 3° increments. At each increment, the knee was flexed under 500 N compression from 0° to 90° simulating an intraoperative examination. The computational model predicted collateral ligament forces, compartmental contact forces, and tibiofemoral internal/external and varus-valgus rotation through the flexion range. The computational model predicted that femoral component external rotation relative to the posterior condylar axis unloads the MCL and the medial compartment; however, these effects were inconsistent from knee to knee. When the femoral component was externally rotated by 9° rather than 0° in knees one, two, and three, the maximum force carried by the MCL decreased a respective 55, 88, and 297 N; the medial contact forces decreased at most a respective 90, 190, and 570 N; external tibial rotation in early flexion increased by a respective 4.6°, 1.1°, and 3.3°; and varus angulation of the tibia relative to the femur in late flexion increased by 8.4°, 8.0°, and 7.9°, respectively. With 3° of femoral component external rotation relative to the posterior condylar axis, the femoral component was still externally rotated by up to 2.7° relative to the sTEA in these three neutrally aligned knees. Variations in MCL force from knee to knee with 3° of femoral component external rotation were related to the ratio of the distances from the femoral insertion of the MCL to the posterior and distal cuts of the implant; the closer this ratio was to 1, the more uniform were the MCL tensions from 0° to 90° flexion. A larger ratio of distances from the femoral insertion of the MCL to the posterior and distal cuts may cause clinically relevant increases in both MCL tension and compartmental contact forces. To obtain more consistent ligament tensions through flexion, it may be important to locate the posterior and distal aspects of the femoral component with respect to the proximal insertion of the MCL such that a ratio of 1 is achieved.

Intraarticular arthrofibrosis of the knee alters patellofemoral contact biomechanics.

PubMed

Mikula, Jacob D; Slette, Erik L; Dahl, Kimi D; Montgomery, Scott R; Dornan, Grant J; O'Brien, Luke; Turnbull, Travis Lee; Hackett, Thomas R

2017-12-19

Arthrofibrosis in the suprapatellar pouch and anterior interval can develop after knee injury or surgery, resulting in anterior knee pain. These adhesions have not been biomechanically characterized. The biomechanical effects of adhesions in the suprapatellar pouch and anterior interval during simulated quadriceps muscle contraction from 0 to 90° of knee flexion were assessed. Adhesions of the suprapatellar pouch and anterior interval were hypothesized to alter the patellofemoral contact biomechanics and increase the patellofemoral contact force compared to no adhesions. Across all flexion angles, suprapatellar adhesions increased the patellofemoral contact force compared to no adhesions by a mean of 80 N. Similarly, anterior interval adhesions increased the contact force by a mean of 36 N. Combined suprapatellar and anterior interval adhesions increased the mean patellofemoral contact force by 120 N. Suprapatellar adhesions resulted in a proximally translated patella from 0 to 60°, and anterior interval adhesions resulted in a distally translated patella at all flexion angles other than 15° (p < 0.05). The most important finding in this study was that patellofemoral contact forces were significantly increased by simulated adhesions in the suprapatellar pouch and anterior interval. Anterior knee pain and osteoarthritis may result from an increase in patellofemoral contact force due to patellar and quadriceps tendon adhesions. For these patients, arthroscopic lysis of adhesions may be beneficial.

Joint torques and joint reaction forces during squatting with a forward or backward inclined Smith machine.

PubMed

Biscarini, Andrea; Botti, Fabio M; Pettorossi, Vito E

2013-02-01

We developed a biomechanical model to determine the joint torques and loadings during squatting with a backward/forward-inclined Smith machine. The Smith squat allows a large variety of body positioning (trunk tilt, foot placement, combinations of joint angles) and easy control of weight distribution between forefoot and heel. These distinctive aspects of the exercise can be managed concurrently with the equipment inclination selected to unload specific joint structures while activating specific muscle groups. A backward (forward) equipment inclination decreases (increases) knee torque, and compressive tibiofemoral and patellofemoral forces, while enhances (depresses) hip and lumbosacral torques. For small knee flexion angles, the strain-force on the posterior cruciate ligament increases (decreases) with a backward (forward) equipment inclination, whereas for large knee flexion angles, this behavior is reversed. In the 0 to 60 degree range of knee flexion angles, loads on both cruciate ligaments may be simultaneously suppressed by a 30 degree backward equipment inclination and selecting, for each value of the knee angle, specific pairs of ankle and hip angles. The anterior cruciate ligament is safely maintained unloaded by squatting with backward equipment inclination and uniform/forward foot weight distribution. The conditions for the development of anterior cruciate ligament strain forces are clearly explained.

Clinical, objective, and functional outcomes of manipulation under anesthesia to treat knee stiffness following total knee arthroplasty.

PubMed

Issa, Kimona; Kapadia, Bhaveen H; Kester, Mark; Khanuja, Harpal S; Delanois, Ronald E; Mont, Michael A

2014-03-01

The purpose of this study was to determine the clinical outcomes of manipulation under anesthesia (MUA) in a cohort who had developed knee stiffness following total knee arthroplasty (TKA). One-hundred and forty-five TKAs in 134 patients who had undergone MUA were compared to the remaining 1973 TKAs in 1671 patients who did not develop this condition. At a mean follow-up of 51 months (range, 24 to 85 months), the mean gains in flexion in the MUA cohort were 33° (range, 5° to 65°). The final range-of-motion in the MUA cohort was lower than the comparison cohort (114° versus 125°) however, this would meet the required flexion for activities of daily living. There were no differences in the Knee Society objective and functional scores between the two cohorts. It is encouraging that MUA cohort outcomes were comparable to outcomes of patients who did not develop knee stiffness. © 2014.

Squatting, lunging and kneeling provided similar kinematic profiles in healthy knees-A systematic review and meta-analysis of the literature on deep knee flexion kinematics.

PubMed

Galvin, Catherine R; Perriman, Diana M; Newman, Phillip M; Lynch, Joseph T; Smith, Paul N; Scarvell, Jennie M

2018-05-22

Understanding healthy deep flexion kinematics will inform the design of conservative clinical rehabilitation strategies for knee osteoarthritis and contribute to improved knee prosthesis design. This study is a systematic review and meta-analysis of the kinematic outcomes measured at the healthy tibiofemoral joint during loaded deep knee flexion. A computerised literature search and bibliography review without date restriction identified twelve studies with 164 participants aged 25-61 years in-vivo, and 69-93 years in-vitro. Flexion higher than 120° was achieved by squatting, lunging or kneeling. Measurement technologies in-vivo included radiographs, open MRI and 2D-3D MRI or CT image registration on fluoroscopy. Microscribe was used in-vitro. Outcomes were either six degrees-of-freedom based on femur movement or contact patterns on the tibial plateau. The meta-analysis demonstrated that in-vivo, between 120° and 135° of flexion, the tibia internally rotated (mean difference (MD) = 4.6°, 95% CI 3.55° to 5.64°). Both the medial-femoral-condyle and lateral-femoral-condyle translated posteriorly, (MD = 10.4 mm, 95% CI 6.9 to 13.9 mm) and (MD = 5.55 mm, 95% CI 4.64 to 6.46 mm) respectively. There was some evidence of femoral medial translation (3.8 mm) and adduction (1.9° to 3.3°), together with medial compression (1.7 mm) and lateral distraction (1.9) mm. Across the in-vivo studies, consistent kinematic patterns emerged; despite the various measurement technologies and reference methods. In contrast, in-vivo and in-vitro results were contradictory. This systematic review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) on 25 February 2017 (registration number: 42017057614). Copyright © 2018 Elsevier B.V. All rights reserved.

[Clinical significance of Q-angle under different conditions in recurrent patellar dislocation].

PubMed

Wang, Zhijie; Chen, You; Li, Anping; Long, Yi

2014-01-01

To investigate the clinical significance of Q-angle measuring under different conditions in female recurrent patellar dislocation female patients. Between August 2012 and March 2013, 10 female patients (11 knees) with recurrent patellar dislocation were collected as trial group; 20 female patients (20 knees) with simple meniscus injury were collected as control group at the same time. Q-angle was measured in extension, 30 degrees flexion, 30 degrees flexion with manual correction, and surgical correction in the trial group, and only in extension and 30 degrees flexion in the control group. Then the difference value of Q-angle between extension and 30 degrees flexion (Q-angle in extension subtracts Q-angle in 30 flexion) were calculated. Independent sample t-test was used to analyze Q-angle degrees in extension, 30 degrees flexion, and the changed degrees of 2 groups. The Q-angle between manual correction and surgical correction of the trial group was analyzed by paired t-test. The Q-angle in extension, Q-angle in 30 degrees flexion, and difference value of Q-angle between extension and 30 degrees flexion were (17.2 +/- 3.6), (14.3 +/- 3.0), and (2.9 +/- 1.9) degrees in the trial group and were (15.2 +/- 3.4), (14.4 +/- 3.5), and (0.8 +/- 1.7) degrees in the control group. No significant difference was found in Q-angle of extension or Q-angle of 30 degrees flexion between 2 groups (P > 0.05), but the difference value of Q-angle between extension and 30 degrees flexion in the trial group was significantly larger than that in the control group (t = 3.253, P = 0.003). The Q-angle in 30 degrees flexion with manual correction and surgical correction in the trial group was (19.8 +/- 3.4) degrees and (18.9 +/- 3.8) degrees respectively, showing no significant difference (t = 2.193, P = 0.053). When a female patient's Q-angle in 30 degrees flexion knee changes obviously compared with Q-angle in extension position, recurrent patellar dislocation should be considered. For female patients with recurrent patellar dislocation, the preoperative Q-angle in 30 degrees flexion with manual correction should be measured, which can help increasing the accuracy of evaluation whether rearrangement should be performed.

Fatigue influences lower extremity angular velocities during a single-leg drop vertical jump.

PubMed

Tamura, Akihiro; Akasaka, Kiyokazu; Otsudo, Takahiro; Shiozawa, Junya; Toda, Yuka; Yamada, Kaori

2017-03-01

[Purpose] Fatigue alters lower extremity landing strategies and decreases the ability to attenuate impact during landing. The purpose of this study was to reveal the influence of fatigue on dynamic alignment and joint angular velocities in the lower extremities during a single leg landing. [Subjects and Methods] The 34 female college students were randomly assigned to either the fatigue or control group. The fatigue group performed single-leg drop vertical jumps before, and after, the fatigue protocol, which was performed using a bike ergometer. Lower extremity kinematic data were acquired using a three-dimensional motion analysis system. The ratio of each variable (%), for the pre-fatigue to post-fatigue protocols, were calculated to compare differences between each group. [Results] Peak hip and knee flexion angular velocities increased significantly in the fatigue group compared with the control group. Furthermore, hip flexion angular velocity increased significantly between each group at 40 milliseconds after initial ground contact. [Conclusion] Fatigue reduced the ability to attenuate impact by increasing angular velocities in the direction of hip and knee flexion during landings. These findings indicate a requirement to evaluate movement quality over time by measuring hip and knee flexion angular velocities in landings during fatigue conditions.

Effects of fatigue on lower limb, pelvis and trunk kinematics and muscle activation: Gender differences.

PubMed

Lessi, Giovanna Camparis; Dos Santos, Ana Flávia; Batista, Luis Fylipe; de Oliveira, Gabriela Clemente; Serrão, Fábio Viadanna

2017-02-01

Muscle fatigue is associated with biomechanical changes that may lead to anterior cruciate ligament (ACL) injuries. Alterations in trunk and pelvis kinematics may also be involved in ACL injury. Although some studies have compared the effects of muscle fatigue on lower limb kinematics between men and women, little is known about its effects on pelvis and trunk kinematics. The aim of the study was to compare the effects of fatigue on lower limb, pelvis and trunk kinematics and muscle activation between men and women during landing. The participants included forty healthy subjects. We performed kinematic analysis of the trunk, pelvis, hip and knee and muscle activation analysis of the gluteal muscles, vastus lateralis and biceps femoris, during a single-leg landing before and after fatigue. Men had greater trunk flexion than women after fatigue. After fatigue, a decrease in peak knee flexion and an increase in Gmax and BF activation were observed. The increase in the trunk flexion can decrease the anterior tibiofemoral shear force resulted from the lower knee flexion angle, thereby decreasing the stress on the ACL. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of robotic-assisted and conventional manual implantation of a primary total knee arthroplasty.

PubMed

Park, Sang Eun; Lee, Chun Taek

2007-10-01

This study was aimed to compare robotic-assisted implantation of a total knee arthroplasty with conventional manual implantation. We controlled, randomized, and reviewed 72 patients for total knee arthroplasty assigned to undergo either conventional manual implantation (excluding navigation-assisted implantation cases) of a Zimmer LPS prosthesis (Zimmer, Warsaw, Ind) (30 patients: group 1) or robotic-assisted implantation of such a prosthesis (32 patients: group 2). The femoral flexion angle (gamma angle) and tibial angle (delta angle) in the lateral x-ray of group 1 were 4.19 +/- 3.28 degrees and 89.7 +/- 1.7 degrees, and those of group 2 were 0.17 +/- 0.65 degrees and 85.5 +/- 0.92 degrees. The major complications were from improper small skin incision during a constraint attempt of minimally invasive surgery and during bulk fixation frame pins insertion. Robotic-assisted technology had definite advantages in terms of preoperative planning, accuracy of the intraoperative procedure, and postoperative follow-up, especially in the femoral flexion angle (gamma angle) and tibial flexion angle (delta angle) in the lateral x-ray, and in the femoral flexion angle (alpha angle) in the anteroposterior x-ray. But a disadvantage was the high complication rate in early stage.

Effect of Human Movement on Galvanic Intra-Body Communication during Single Gait Cycle

NASA Astrophysics Data System (ADS)

Ibrahim, I. W.; Razak, A. H. A.; Ahmad, A.; Salleh, M. K. M.

2015-11-01

Intra-body communication (IBC) is a communication system that uses human body as a signal transmission medium. From previous research, two coupling methods of IBC were concluded which are capacitive coupling and galvanic coupling. This paper investigates the effect of human movement on IBC using the galvanic coupling method. Because the human movement is control by the limb joint, the knee flexion angle during gait cycle was used to examine the influence of human movement on galvanic coupling IBC. The gait cycle is a cycle of people walking that start from one foot touch the ground till that foot touch the ground again. Frequency range from 300 kHz to 200MHz was swept in order to investigate the signal transmission loss and the result was focused on operating frequency 70MHz to 90MHz. Results show that the transmission loss varies when the knee flexion angle increased. The highest loss of signal at frequency range between 70MHz to 90 MHz was 69dB when the knee flexion angle is 50° and the minimum loss was 51dB during the flexion angle is 5°.

Variability of Plyometric and Ballistic Exercise Technique Maintains Jump Performance.

PubMed

Chandler, Phillip T; Greig, Matthew; Comfort, Paul; McMahon, John J

2018-06-01

Chandler, PT, Greig, M, Comfort, P, and McMahon, JJ. Variability of plyometric and ballistic exercise technique maintains jump performance. J Strength Cond Res 32(6): 1571-1582, 2018-The aim of this study was to investigate changes in vertical jump technique over the course of a training session. Twelve plyometric and ballistic exercise-trained male athletes (age = 23.4 ± 4.6 years, body mass = 78.7 ± 18.8 kg, height = 177.1 ± 9.0 cm) performed 3 sets of 10 repetitions of drop jump (DJ), rebound jump (RJ) and squat jump (SJ). Each exercise was analyzed from touchdown to peak joint flexion and peak joint flexion to take-off. Squat jump was analyzed from peak joint flexion to take-off only. Jump height, flexion and extension time and range of motion, and instantaneous angles of the ankle, knee, and hip joints were measured. Separate 1-way repeated analyses of variance compared vertical jump technique across exercise sets and repetitions. Exercise set analysis found that SJ had lower results than DJ and RJ for the angle at peak joint flexion for the hip, knee, and ankle joints and take-off angle of the hip joint. Exercise repetition analysis found that the ankle joint had variable differences for the angle at take-off, flexion, and extension time for RJ. The knee joint had variable differences for flexion time for DJ and angle at take-off and touchdown for RJ. There was no difference in jump height. Variation in measured parameters across repetitions highlights variable technique across plyometric and ballistic exercises. This did not affect jump performance, but likely maintained jump performance by overcoming constraints (e.g., level of rate coding).

The relationship of lateral anatomic structures to exiting guide pins during femoral tunnel preparation utilizing an accessory medial portal.

PubMed

Farrow, Lutul D; Parker, Richard D

2010-06-01

Anatomic reconstruction of the anterior cruciate ligament through an accessory medial portal has become increasingly popular. The purpose of this study is to describe the relationship of guide pin exit points to the lateral anatomic structures when preparing the anterior cruciate ligament femoral tunnel through an accessory medial portal. We utilized seven fresh frozen cadaveric knees. Utilizing an anteromedial approach, a guide wire was placed into the center of each bundle's footprint. Each guide wire was advanced through the lateral femoral cortex. The guide pins were passed at 90, 110, and 130 degrees of knee flexion. The distances from each guide pin to the closest relevant structures on the lateral side of the knee were measured. At 90 degrees the posterolateral bundle guide pin was closest to the lateral condyle articular cartilage (mean 5.4 +/- 2.2 mm) and gastrocnemius tendon (mean 5.7 +/- 2.1 mm). At 110 degrees the posterolateral bundle pin was closest to the gastrocnemius tendon (mean 4.5 +/- 3.4 mm). At 130 degrees the posterolateral bundle pin was closest to the gastrocnemius tendon (mean 7.2 +/- 5.5 mm) and lateral collateral ligament (mean 6.8 +/- 2.1 mm). At 90 degrees the anteromedial bundle guide pin was closest to the articular cartilage (mean 2.0 +/- 2.0 mm). At 110 degrees the anteromedial bundle pin was closest to the articular cartilage (mean 7.4 +/- 3.5 mm) and gastrocnemius tendon (mean 12.3 +/- 3.1 mm). At 130 degrees the AM bundle pin was closest to the gastrocnemius tendon (mean 8.2 +/- 3.2 mm) and LCL (mean 15.1 +/- 2.9 mm). Neither guide pin (anteromedial or posterolateral bundle) put the peroneal nerve at risk at any knee flexion angle. At low knee flexion angles the anteromedial and posterolateral bundle guide pins closely approximated multiple lateral structures when using an accessory medial arthroscopic portal. Utilizing higher flexion angles increases the margin of error when preparing both femoral tunnels. During preparation of the anterior cruciate ligament femoral tunnel through an accessory anteromedial portal the tunnels should be drilled in at least 110 degrees of knee flexion in order to move guide pin exit points away from important lateral knee structures.

Movement Patterns of the Knee During Gait Following ACL Reconstruction: A Systematic Review and Meta-Analysis.

PubMed

Kaur, Mandeep; Ribeiro, Daniel Cury; Theis, Jean-Claude; Webster, Kate E; Sole, Gisela

2016-12-01

Altered gait patterns follow ing anterior cruciate ligament reconstruction (ACLR) may be associated with long-term impairments and post-traumatic osteoarthritis. This systematic review and meta-analysis compared lower limb kinematics and kinetics of the ACL reconstructed knee with (1) the contralateral limb and (2) healthy age-matched participants during walking, stair climbing, and running. The secondary aim was to describe the differences over time following ACLR for these biomechanical variables. Database searches were conducted from inception to July 2014 and updated in August 2015 for studies exploring peak knee angles and moments following ACLR during walking, stair negotiation, and running. Risk of bias was assessed with a modified Downs and Black quality index for all included studies, and meta-analyses were performed. Forest plots were explored qualitatively for recovery of gait variables over time after surgery. A total of 40 studies were included in the review; 26 of these were rated as low risk and 14 as high risk of bias. The meta-analysis included 27 studies. Strong to moderate evidence indicated no significant difference in peak flexion angles between ACLR and control groups during walking and stair ascent. Strong evidence was found for lower peak flexion moments in participants with ACLR compared with control groups and contralateral limb during walking and stair activities. Strong to moderate evidence was found for lower peak adduction moment in ACLR participants for the injured compared with the contralateral limbs during walking and stair descent. The qualitative assessment for recovery over time indicated a pattern towards restoration of peak knee flexion angle with increasing time from post-surgery. Peak knee adduction moments were lower within the first year following surgery and higher than controls during later phases (5 years). Joint kinematics are restored, on average, 6 years following reconstruction, while knee external flexion moments remain lower than controls. Knee adduction moments are lower during early phases following reconstruction, but are higher than controls, on average, 5 years post-surgery. Findings indicate that knee function is not fully restored following reconstruction, and long-term maintenance programs may be needed.

The Effect of Upper Body Mass and Initial Knee Flexion on the Injury Outcome of Post Mortem Human Subject Pedestrian Isolated Legs.

PubMed

Petit, Philippe; Trosseille, Xavier; Dufaure, Nicolas; Dubois, Denis; Potier, Pascal; Vallancien, Guy

2014-11-01

In the ECE 127 Regulation on pedestrian leg protection, as well as in the Euro NCAP test protocol, a legform impactor hits the vehicle at the speed of 40 kph. In these tests, the knee is fully extended and the leg is not coupled to the upper body. However, the typical configuration of a pedestrian impact differs since the knee is flexed during most of the gait cycle and the hip joint applies an unknown force to the femur. This study aimed at investigating the influence of the inertia of the upper body (modelled using an upper body mass fixed at the proximal end of the femur) and the initial knee flexion angle on the lower limb injury outcome. In total, 18 tests were conducted on 18 legs from 9 Post Mortem Human Subjects (PMHS). The principle of these tests was to impact the leg at 40 kph using a sled equipped with 3 crushing steel tubes, the stiffness of which were representative of the front face of a European sedan (bonnet leading edge, bumper and spoiler). The mass of the equipped sled was 74.5 kg. The test matrix was designed to perform 4 tests in 4 configurations combining two upper body masses (either 0 or 3 kg) and two knee angles (0 or 20 degrees) at 40 kph (11 m/s) plus 2 tests at 9 m/s. Autopsies were performed on the lower limbs and an injury assessment was established. The findings of this study were first that the increase of the upper body mass resulted in more severe injuries, second that an initial flexion of the knee, corresponding to its natural position during the gait cycle, decreased the severity of the injuries, and third that based on the injury outcome, a test conducted with no upper body mass and the knee fully extended was as severe as a test conducted with a 3 kg upper body mass and an initial knee flexion of 20°.

Running in ostriches (Struthio camelus): three-dimensional joint axes alignment and joint kinematics.

PubMed

Rubenson, Jonas; Lloyd, David G; Besier, Thor F; Heliams, Denham B; Fournier, Paul A

2007-07-01

Although locomotor kinematics in walking and running birds have been examined in studies exploring many biological aspects of bipedalism, these studies have been largely limited to two-dimensional analyses. Incorporating a five-segment, 17 degree-of-freedom (d.f.) kinematic model of the ostrich hind limb developed from anatomical specimens, we quantified the three-dimensional (3-D) joint axis alignment and joint kinematics during running (at approximately 3.3 m s(-1)) in the largest avian biped, the ostrich. Our analysis revealed that the majority of the segment motion during running in the ostrich occurs in flexion/extension. Importantly, however, the alignment of the average flexion/extension helical axes of the knee and ankle are rotated externally to the direction of travel (37 degrees and 21 degrees , respectively) so that pure flexion and extension at the knee will act to adduct and adbuct the tibiotarsus relative to the plane of movement, and pure flexion and extension at the ankle will act to abduct and adduct the tarsometatarsus relative to the plane of movement. This feature of the limb anatomy appears to provide the major lateral (non-sagittal) displacement of the lower limb necessary for steering the swinging limb clear of the stance limb and replaces what would otherwise require greater adduction/abduction and/or internal/external rotation, allowing for less complex joints, musculoskeletal geometry and neuromuscular control. Significant rotation about the joints' non-flexion/extension axes nevertheless occurs over the running stride. In particular, hip abduction and knee internal/external and varus/valgus motion may further facilitate limb clearance during the swing phase, and substantial non-flexion/extension movement at the knee is also observed during stance. Measurement of 3-D segment and joint motion in birds will be aided by the use of functionally determined axes of rotation rather than assumed axes, proving important when interpreting the biomechanics and motor control of avian bipedalism.

Effects of High Velocity Elastic Band versus Heavy Resistance Training on Hamstring Strength, Activation, and Sprint Running Performance

PubMed Central

Janusevicius, Donatas; Snieckus, Audrius; Skurvydas, Albertas; Silinskas, Viktoras; Trinkunas, Eugenijus; Cadefau, Joan Aureli; Kamandulis, Sigitas

2017-01-01

Hamstring muscle injuries occur during high-speed activities, which suggests that muscular strength at high velocities may be more important than maximal strength. This study examined hamstring adaptations to training for maximal strength and for strength at high velocities. Physically active men (n = 25; age, 23.0 ± 3.2 years) were randomly divided into: (1) a resistance training (RT, n = 8) group, which performed high-load, low-velocity concentric–eccentric hamstring contractions; (2) a resistance training concentric (RTC; n = 9) group, which performed high-load, low-velocity concentric-only hamstring contractions; and (3) a high-velocity elastic band training (HVT, n = 8) group, which performed low-load, high-velocity concentric–eccentric hamstring contractions. Pre- and posttraining tests included hamstring strength on a hamstring-curl apparatus, concentric knee extension–flexion at 60°/s, 240°/s, and 450°/s, eccentric knee flexion at 60°/s and 240°/s, hamstring and quadriceps coactivation, knee flexion and extension frequency in the prone position, and 30-m sprint running speed from a stationary start and with a running start. Knee flexor torque increased significantly by 21.1% ± 8.1% in the RTC group and 16.2% ± 4.2% in the RT group (p < 0.05 for both groups). Hamstring coactivation decreased significantly in both groups. In the HVT group, knee flexion and extension frequency increased by 17.8% ± 8.2%, concentric peak torque of the knee flexors at 450°/s increased by 31.0% ± 12.0%, hamstring coactivation decreased, and running performance over 30 m improved (p < 0.05 for all parameters). These findings suggest that resistance training at high velocities is superior to traditional heavy resistance training for increasing knee flexor strength at high velocities, movement frequency, and sprint running performance. These findings also indicate that traditional training approaches are effective for increasing knee flexor strength and reducing knee extensor coactivation, but this outcome is limited to low and moderate speeds. Key points Resistance training performed at high load and low velocities increases knee flexor strength and decreases hamstring coactivation, whereas does not change strength at high velocity. Elastic band training at high velocities increases strength and decreases hamstring coactivation, particularly at high muscle velocities. Elastic band hamstring training at high velocities has positive effects on both knee flexors and knee extensors, and these benefits transfer positively to sprint performance. PMID:28630577

Post-Cam Design and Contact Stress on Tibial Posts in Posterior-Stabilized Total Knee Prostheses: Comparison Between a Rounded and a Squared Design.

PubMed

Watanabe, Toshifumi; Koga, Hideyuki; Horie, Masafumi; Katagiri, Hiroki; Sekiya, Ichiro; Muneta, Takeshi

2017-12-01

The post-cam mechanism in posterior stabilized (PS) prostheses plays an important role in total knee arthroplasty (TKA). The purpose of this study is to clarify the difference of the contact stress on the tibial post between a rounded post-cam design and a squared design during deep knee flexion and at hyperextension using the three-dimensional (3D) finite element models. We created 2 types of 3D, finite element models of PS prostheses (types A and B), whose surfaces were identical except for the post-cam geometries: type A has a rounded post-cam design, while type B has a squared design. Both types have a similar curved-shape intercondylar notch of the femoral component. Stress distributions, peak contact stresses, and contact areas on the tibial posts at 90°, 120°, and 150° flexion with/without 10° tibial internal rotation and at 10° hyperextension were compared between the 2 models. Type B demonstrated more concentrated stress distribution compared to type A. The peak contact stresses were similar in both groups during neutral flexion; however, the stresses were much higher in type B during flexion with 10° rotation and at hyperextension. The higher peak contact stresses corresponded to the smaller contact areas in the tibial post. A rounded post-cam design demonstrated less stress concentration during flexion with rotation and at hyperextension compared with a squared design. The results would be useful for development of implant designs and prediction of the contact stress on the tibial post in PS total knee arthroplasty. Copyright © 2017 Elsevier Inc. All rights reserved.

Interdependence of torque, joint angle, angular velocity and muscle action during human multi-joint leg extension.

PubMed

Hahn, Daniel; Herzog, Walter; Schwirtz, Ansgar

2014-08-01

Force and torque production of human muscles depends upon their lengths and contraction velocity. However, these factors are widely assumed to be independent of each other and the few studies that dealt with interactions of torque, angle and angular velocity are based on isolated single-joint movements. Thus, the purpose of this study was to determine force/torque-angle and force/torque-angular velocity properties for multi-joint leg extensions. Human leg extension was investigated (n = 18) on a motor-driven leg press dynamometer while measuring external reaction forces at the feet. Extensor torque in the knee joint was calculated using inverse dynamics. Isometric contractions were performed at eight joint angle configurations of the lower limb corresponding to increments of 10° at the knee from 30 to 100° of knee flexion. Concentric and eccentric contractions were performed over the same range of motion at mean angular velocities of the knee from 30 to 240° s(-1). For contractions of increasing velocity, optimum knee angle shifted from 52 ± 7 to 64 ± 4° knee flexion. Furthermore, the curvature of the concentric force/torque-angular velocity relations varied with joint angles and maximum angular velocities increased from 866 ± 79 to 1,238 ± 132° s(-1) for 90-50° knee flexion. Normalised eccentric forces/torques ranged from 0.85 ± 0.12 to 1.32 ± 0.16 of their isometric reference, only showing significant increases above isometric and an effect of angular velocity for joint angles greater than optimum knee angle. The findings reveal that force/torque production during multi-joint leg extension depends on the combined effects of angle and angular velocity. This finding should be accounted for in modelling and optimisation of human movement.

The effects of onabotulinum toxin A injection into rectus femoris muscle in hemiplegic stroke patients with stiff-knee gait: a placebo-controlled, nonrandomized trial.

PubMed

Tok, Fatih; Balaban, Birol; Yaşar, Evren; Alaca, Rdvan; Tan, Arif Kenan

2012-04-01

This study aimed to compare the efficacy of onabotulinum toxin A (onabot) injection into the rectus femoris muscle with that of placebo in the treatment of hemiplegic stroke patients presenting with stiff-knee gait. Twenty-five chronic hemiparetic stroke patients presenting with a stiff-knee gait were included in this study. Fifteen patients received 100-125 U of onabot, and 10 patients received placebo into the rectus femoris muscle. Three-dimensional gait analysis, energy expenditure, 10-m and 6-min walk tests, and spasticity level of the rectus femoris were evaluated at baseline and 2 mos posttreatment. The mean age of patients who received onabot was 53.86 ± 14.74 yrs and of those who received placebo was 59.00 ± 8.11 yrs. At study onset, groups were similar with respect to all parameters (P > 0.05). We observed significant improvement in knee flexion (7 degrees average) during swing and a reduction in energy cost of 0.8-J/kg per meter response to injection of 100-125 U of onabot into the rectus femoris muscle. Onabot treatment significantly reduced muscle tone and improved knee kinematics, energy expenditure during walking, and functional assessments at 2 mos (P < 0.05); however, placebo had no effects on these parameters. Moreover, maximum knee flexion at swing and energy expenditure in the onabot group was significantly better than placebo at 2 mos (P < 0.05). Our results showed the superiority of onabot over placebo in increasing knee flexion during swing phase and decreasing energy expenditure. The application of onabot into the rectus femoris muscle in stroke patients who presented with stiff-knee gait may be a treatment option to provide independent, safe, and less tiring ambulation.

The effect of technique change on knee loads during sidestep cutting.

PubMed

Dempsey, Alasdair R; Lloyd, David G; Elliott, Bruce C; Steele, Julie R; Munro, Bridget J; Russo, Kylie A

2007-10-01

To identify the effect of modifying sidestep cutting technique on knee loads and predict what impact such change would have on the risk of noncontact anterior cruciate ligament injury. A force platform and motion-analysis system were used to record ground-reaction forces and track the trajectories of markers on 15 healthy males performing sidestep cutting tasks using their normal technique and nine different imposed techniques. A kinematic and inverse dynamic model was used to calculate the three-dimensional knee postures and moments. The imposed techniques of foot wide and torso leaning in the opposite direction to the cut resulted in increased peak valgus moments experienced in weight acceptance. Higher peak internal rotation moments were found for the foot wide and torso rotation in the opposite direction to the cut techniques. The foot rotated in technique resulted in lower mean flexion/extension moments, whereas the foot wide condition resulted in higher mean flexion/extension moments. The flexed knee, torso rotated in the opposite direction to the cut and torso leaning in the same direction as the cut techniques had significantly more knee flexion at heel strike. Sidestep cutting technique had a significant effect on loads experienced at the knee. The techniques that produced higher valgus and internal rotation moments at the knee, such as foot wide, torso leaning in the opposite direction to the cut and torso rotating in the opposite direction to the cut, may place an athlete at higher risk of injury because these knee loads have been shown to increase the strain on the anterior cruciate ligament. Training athletes to avoid such body positions may result in a reduced risk of noncontact anterior cruciate ligament injures.

Magnetic resonance imaging of the posterior cruciate ligament in flexion.

PubMed

Craddock, William; Smithers, Troy; Harris, Craig; du Moulin, William; Molnar, Robert

2018-06-01

Posterior cruciate ligament (PCL) injuries of the knee are common and sometimes difficult to diagnose. Magnetic resonance imaging (MRI), performed using standard orthogonal plane views, is the investigation of choice. It can be particularly difficult to differentiate acute partial and complete tears and identify elongation of chronic healed tears. The aim of the paper is to describe a new method of positioning the patient with the knee flexed at 90°, allowing the PCL to be visualised in a position of greatest length and tension which may assist in differentiating and identifying these injuries. Four symptomatic patients with suspected PCL injuries, two acute and two chronic, were MRI scanned using a routine protocol with the knee in extension before performing oblique sagittal fast spin-echo (FSE) proton-density (PD) sequences with the knee positioned in 90° of flexion. The appearance of the PCLs were then qualitatively assessed. MRI scanning with the knee in flexion identified more extensive PCL injury than standard imaging. In the two patients with acute injuries, partial tears on the standard orthogonal plane views were found to be complete ruptures. In the two patients with chronic injuries, elongation of the PCL not identifiable on the standard orthogonal plane views was apparent. MRI scanning of the PCL with the knee flexed at 90° may help in differentiating partial and complete ruptures of the PCL and identifying elongation of the PCL in chronic injuries. Copyright © 2018 Elsevier B.V. All rights reserved.

Combined Effects of Fatigue and Surface Instability on Jump Biomechanics in Elite Athletes.

PubMed

Prieske, Olaf; Demps, Marie; Lesinski, Melanie; Granacher, Urs

2017-09-01

The present study aimed to examine the effects of fatigue and surface instability on kinetic and kinematic jump performance measures. Ten female and 10 male elite volleyball players (18±2 years) performed repetitive vertical double-leg box jumps until failure. Pre and post fatigue, jump height/performance index, ground reaction force and knee flexion/valgus angles were assessed during drop and countermovement jumps on stable and unstable surfaces. Fatigue, surface condition, and sex resulted in significantly lower drop jump performance and ground reaction force (p≤0.031, 1.1≤d≤3.5). Additionally, drop jump knee flexion angles were significantly lower following fatigue (p=0.006, d=1.5). A significant fatigue×surface×sex interaction (p=0.020, d=1.2) revealed fatigue-related decrements in drop jump peak knee flexion angles under unstable conditions and in men only. Knee valgus angles were higher on unstable compared to stable surfaces during drop jumps and in females compared to males during drop and countermovement jumps (p≤0.054, 1.0≤d≤1.1). Significant surface×sex interactions during countermovement jumps (p=0.002, d=1.9) indicated that knee valgus angles at onset of ground contact were significantly lower on unstable compared to stable surfaces in males but higher in females. Our findings revealed that fatigue and surface instability resulted in sex-specific knee motion strategies during jumping in elite volleyball players. © Georg Thieme Verlag KG Stuttgart · New York.

Isokinetic Strength and Endurance Tests used Pre- and Post-Spaceflight: Test-Retest Reliability

NASA Technical Reports Server (NTRS)

Laughlin, Mitzi S.; Lee, Stuart M. C.; Loehr, James A.; Amonette, William E.

2009-01-01

To assess changes in muscular strength and endurance after microgravity exposure, NASA measures isokinetic strength and endurance across multiple sessions before and after long-duration space flight. Accurate interpretation of pre- and post-flight measures depends upon the reliability of each measure. The purpose of this study was to evaluate the test-retest reliability of the NASA International Space Station (ISS) isokinetic protocol. Twenty-four healthy subjects (12 M/12 F, 32.0 +/- 5.6 years) volunteered to participate. Isokinetic knee, ankle, and trunk flexion and extension strength as well as endurance of the knee flexors and extensors were measured using a Cybex NORM isokinetic dynamometer. The first weekly session was considered a familiarization session. Data were collected and analyzed for weeks 2-4. Repeated measures analysis of variance (alpha=0.05) was used to identify weekly differences in isokinetic measures. Test-retest reliability was evaluated by intraclass correlation coefficients (ICC) (3,1). No significant differences were found between weeks in any of the strength measures and the reliability of the strength measures were all considered excellent (ICC greater than 0.9), except for concentric ankle dorsi-flexion (ICC=0.67). Although a significant difference was noted in weekly endurance measures of knee extension (p less than 0.01), the reliability of endurance measure by week were considered excellent for knee flexion (ICC=0.97) and knee extension (ICC=0.96). Except for concentric ankle dorsi-flexion, the isokinetic strength and endurance measures are highly reliable when following the NASA ISS protocol. This protocol should allow accurate interpretation isokinetic data even with a small number of crew members.

Effect of adductor canal block on pain in patients with severe pain after total knee arthroplasty: a randomized study with individual patient analysis.

PubMed

Grevstad, U; Mathiesen, O; Lind, T; Dahl, J B

2014-05-01

Total knee arthroplasty (TKA) is associated with varying degrees of pain. A considerable proportion (25-40%) of patients experience severe pain, despite a comprehensive multimodal analgesic regimen. We hypothesized that adductor canal block (ACB) would reduce pain in this patient category compared with placebo. Fifty patients with severe pain, defined as having a visual analogue scale (VAS) pain score of >60 during active flexion of the knee on the first or the second postoperative day after TKA, were included in this randomized, double-blind, placebo-controlled trial. All the patients had received a comprehensive multimodal analgesic regimen. Group A received an ACB with ropivacaine 0.75%, 30 ml at time 0 and isotonic saline after 45 min. Group B received an ACB with isotonic saline at time 0 and ropivacaine 0.75%, 30 ml after 45 min. A 32-mm difference in VAS pain score, during active flexion of the knee (primary endpoint), was observed in favour of Group A, 95% confidence interval (CI): 23-42, P<0.0001. At rest, the difference in VAS pain score was 15 mm in favour of Group A, 95% CI: 8-23 mm, P=0.0001. Individual patient analysis revealed that 25% of the patients had no effect during active flexion. At rest, however, only 8% had more than mild pain after ACB compared with 57% at inclusion. ACB reduced VAS with 32 mm, during active flexion of the knee, in patients with severe pain after TKA, but a large proportion (78%) still had at least moderate, movement-related pain. Clinical trial registration www.clinicaltrials.gov, NCT01549704.

Lower Limb Kinematics and Metabolic Cost During Elliptical Exercises and Treadmill Running.

PubMed

Chester, Stephanie; Zucker-Levin, Audrey; Melcher, Daniel A; Peel, Shelby A; Bloomer, Richard J; Paquette, Max R

2016-04-01

The purpose of this study was to compare knee and hip joint kinematics previously associated with anterior knee pain and metabolic cost among conditions including treadmill running (TR), standard elliptical (SE), and lateral elliptical (LE) in healthy runners. Joint kinematics and metabolic parameters of 16 runners were collected during all 3 modalities using motion capture and a metabolic system, respectively. Sagittal knee range of motion (ROM) was greater in LE (P < .001) and SE (P < .001) compared with TR. Frontal and transverse plane hip ROM were greater in LE compared with SE (P < .001) and TR (P < .001). Contralateral pelvic drop ROM was smaller in SE compared with TR (P = .002) and LE (P = .005). Similar oxygen consumption was found during LE and TR (P = .39), but LE (P < .001) and TR (P < .001) required greater oxygen consumption than SE. Although LE yields similar metabolic cost to TR and produces hip kinematics that may help strengthen hip abductors, greater knee flexion and abduction during LE may increase symptoms in runners with anterior knee pain. The findings suggest that research on the implications of elliptical exercise for injured runners is needed.

Gait analysis of patients with knee osteoarthritis highlights a pathological mechanical pathway and provides a basis for therapeutic interventions

PubMed Central

Favre, Julien; Jolles, Brigitte M.

2016-01-01

Knee osteoarthritis (OA) is a painful and incapacitating disease affecting a large portion of the elderly population, for which no cure exists. There is a critical need to enhance our understanding of OA pathogenesis, as a means to improve therapeutic options. Knee OA is a complex disease influenced by many factors, including the loading environment. Analysing knee biomechanics during walking - the primary cyclic load-bearing activity - is therefore particularly relevant. There is evidence of meaningful differences in the knee adduction moment, flexion moment and flexion angle during walking between non-OA individuals and patients with medial knee OA. Furthermore, these kinetic and kinematic gait variables have been associated with OA progression. Gait analysis provides the critical information needed to understand the role of ambulatory biomechanics in OA development, and to design therapeutic interventions. Multidisciplinary research is necessary to relate the biomechanical alterations to the structural and biological components of OA. Cite this article: Favre J, Jolles BM. Analysis of gait, knee biomechanics and the physiopathology of knee osteoarthritis in the development of therapeutic interventions. EFORT Open Rev 2016;1:368-374. DOI: 10.1302/2058-5241.1.000051. PMID:28461915

Different intraoperative kinematics with comparable clinical outcomes of ultracongruent and posterior stabilized mobile-bearing total knee arthroplasty.

PubMed

Kim, Tae Woo; Lee, Sang Min; Seong, Sang Cheol; Lee, Sahnghoon; Jang, Jak; Lee, Myung Chul

2016-09-01

There remains no consensus as to whether mobile total knee arthroplasty (TKA) should use a posterior cruciate ligament-sacrificing ultracongruent (UC) or a posterior cruciate ligament-substituting posterior stabilized (PS) prosthesis. The purpose of this study was to assess intraoperative kinematics and clinical outcomes of UC and PS rotating platform mobile-bearing TKA. In this randomized controlled study, mobile UC TKA prostheses (n = 45) were compared with mobile PS TKA prostheses (n = 45) with regard to intraoperative kinematics and clinical outcomes. The passive kinematic study using intraoperative navigation system included anterior/posterior translation, varus/valgus alignment and rotation of femur during flexion. The patients were clinically and radiographically evaluated over a 3-year follow-up. Paradoxical anterior translation of the femur was 10.8 ± 5.2 mm in the UC knee from 0° to 82° of knee flexion and 8.7 ± 3.0 mm in the PS knee from 0° to 70° of knee flexion (p = 0.027). Paradoxical internal rotation of the femur was 5.8° in the UC knees and 9.9° in the PS knees (p = 0.003). But, there was no significant difference between the groups in regard to the coronal alignment. There was no significant difference in the range of motion, KS knee scores, KS function scores, and WOMAC index scores. Despite different intraoperative kinematics between mobile UC and mobile PS TKA, neither design reproduced physiologic knee kinematics and there was no difference in clinical outcomes between the two groups. The clinical relevance of the study is that despite different intraoperative kinematics, UC design can be a considerable alternative to PS design in mobile-bearing TKA in respect of clinical outcomes. II.

Neuromuscular fatigue and tibiofemoral joint biomechanics when transitioning from non-weight bearing to weight bearing.

PubMed

Schmitz, Randy J; Kim, Hyunsoo; Shultz, Sandra J

2015-01-01

Fatigue is suggested to be a risk factor for anterior cruciate ligament injury. Fatiguing exercise can affect neuromuscular control and laxity of the knee joint, which may render the knee less able to resist externally applied loads. Few authors have examined the effects of fatiguing exercise on knee biomechanics during the in vivo transition of the knee from non-weight bearing to weight bearing, the time when anterior cruciate ligament injury likely occurs. To investigate the effect of fatiguing exercise on tibiofemoral joint biomechanics during the transition from non-weight bearing to early weight bearing. Cross-sectional study. Research laboratory. Ten participants (5 men and 5 women; age = 25.3 ± 4.0 years) with no previous history of knee-ligament injury to the dominant leg. Participants were tested before (preexercise) and after (postexercise) a protocol consisting of repeated leg presses (15 repetitions from 10°-40° of knee flexion, 10 seconds' rest) against a 60% body-weight load until they were unable to complete a full bout of repetitions. Electromagnetic sensors measured anterior tibial translation and knee-flexion excursion during the application of a 40% body-weight axial compressive load to the bottom of the foot, simulating weight acceptance. A force transducer recorded axial compressive force. The axial compressive force (351.8 ± 44.3 N versus 374.0 ± 47.9 N; P = .018), knee-flexion excursion (8.0° ± 4.0° versus 10.2° ± 3.7°; P = .046), and anterior tibial translation (6.7 ± 1.7 mm versus 8.2 ± 1.9 mm; P < .001) increased from preexercise to postexercise. No significant correlations were noted. Neuromuscular fatigue may impair initial knee-joint stabilization during weight acceptance, leading to greater accessory motion at the knee and the potential for greater anterior cruciate ligament loading.

Immediate effects of a new microprocessor-controlled prosthetic knee joint: a comparative biomechanical evaluation.

PubMed

Bellmann, Malte; Schmalz, Thomas; Ludwigs, Eva; Blumentritt, Siegmar

2012-03-01

To investigate the immediate biomechanical effects after transition to a new microprocessor-controlled prosthetic knee joint. Intervention cross-over study with repeated measures. Only prosthetic knee joints were changed. Motion analysis laboratory. Men (N=11; mean age ± SD, 36.7±10.2y; Medicare functional classification level, 3-4) with unilateral transfemoral amputation. Two microprocessor-controlled prosthetic knee joints: C-Leg and a new prosthetic knee joint, Genium. Static prosthetic alignment, time-distance parameters, kinematic and kinetic parameters, and center of pressure. After a half-day training and an additional half-day accommodation, improved biomechanical outcomes were demonstrated by the Genium: lower ground reaction forces at weight acceptance during level walking at various velocities, increased swing phase flexion angles during walking on a ramp, and level walking with small steps. Maximum knee flexion angle during swing phase at various velocities was nearly equal for Genium. Step-over-step stair ascent with the Genium knee was more physiologic as demonstrated by a more equal load distribution between the prosthetic and contralateral sides and a more natural gait pattern. When descending stairs and ramps, knee flexion moments with the Genium tended to increase. During quiet stance on a decline, subjects using Genium accepted higher loading of the prosthetic side knee joint, thus reducing same side hip joint loading as well as postural sway. In comparision to the C-Leg, the Genium demonstrated immediate biomechanical advantages during various daily ambulatory activities, which may lead to an increase in range and diversity of activity of people with above-knee amputations. Results showed that use of the Genium facilitated more natural gait biomechanics and load distribution throughout the affected and sound musculoskeletal structure. This was observed during quiet stance on a decline, walking on level ground, and walking up and down ramps and stairs. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Three-dimensional in vivo patellofemoral kinematics and contact area of anterior cruciate ligament-deficient and -reconstructed subjects using magnetic resonance imaging.

PubMed

Shin, Choongsoo S; Carpenter, R Dana; Majumdar, Sharmila; Ma, C Benjamin

2009-11-01

The purpose of this study was to test whether (1) the 3-dimensional in vivo patellofemoral kinematics and patellofemoral contact area of anterior cruciate ligament (ACL)-deficient knees are different from those of normal, contralateral knees and (2) ACL reconstruction restores in vivo patellofemoral kinematics and contact area. Ten ACL-deficient knees and twelve ACL-reconstructed knees, as well as the contralateral uninjured knees, were tested. Magnetic resonance imaging was performed at full extension and 40 degrees of flexion under simulated partial weight-bearing conditions. Six-degrees of freedom patellofemoral kinematics, patellofemoral contact area, and contact location were analyzed by use of magnetic resonance image-based 3-dimensional patellofemoral knee models. The patella in the ACL-deficient knees underwent significantly more lateral tilt during flexion (P < .05) and tended to translate more laterally (P = .083) than the patella in contralateral knees. After ACL reconstruction, no kinematic parameters were significantly different from those in contralateral knees. The patellofemoral contact areas of ACL-deficient knees at both the extended and flexed positions (37 +/- 22 mm(2) and 357 +/- 53 mm(2), respectively) were significantly smaller than those of contralateral knees (78 +/- 45 mm(2) and 437 +/- 119 mm(2), respectively) (P < .05). After reconstruction, the patellofemoral contact area of ACL-reconstructed knees in the extended position (86 +/- 41 mm(2)) was significantly larger (P < .05) than that of contralateral knees (50 +/- 34 mm(2)), but no difference was detected in the flexed position. Reproducibility of all patellofemoral kinematic parameters, contact centroid translation, and contact area showed coefficients of variation of less than 6.8%. ACL injuries alter patellofemoral kinematics including patellar tilt and patellar lateral translation, but ACL reconstruction with hamstring or allograft restores altered patellar tilt. ACL injuries reduce the patellofemoral contact area at both the extended and flexed positions, but ACL reconstruction enlarges the patellofemoral contact area at extension and restores the normal contact area at low angles of flexion. Level III, case-control study.

Ballistic movements of jumping legs implemented as variable components of cricket behaviour.

PubMed

Hustert, R; Baldus, M

2010-12-01

Ballistic accelerations of a limb or the whole body require special joint mechanisms in many animals. Specialized joints can be moved by stereotypic or variable motor control during motor patterns with and without ballistic components. As a model of variable motor control, the specialized femur-tibia (knee) joints of cricket (Acheta domesticus) hindlegs were studied during ballistic kicking, jumping and swimming and in non-ballistic walking. In this joint the tendons of the antagonistic flexor and the extensor muscles attach at different distances from the pivot and the opposed lever arms form an angle of 120 deg. A 10:1 ratio of their effective lever arms at full knee flexion helps to prepare for most ballistic extensions: the tension of the extensor can reach its peak while it is restrained by flexor co-contraction. In kicks, preparatory flexion is rapid and the co-contraction terminates just before knee extensions. Therefore, mainly the stored tension of the extensor muscle accelerates the small mass of the tibia. Jumps are prepared with slower extensor-flexor co-contractions that flex both knees simultaneously and then halt to rotate both legs outward to a near horizontal level. From there, catapult extension of both knees accelerates the body, supported by continued high frequency motor activity to their tibia extensor muscles during the ongoing push-off from the substrate. Premature extension of one knee instantly takes load from the lagging leg that extends and catches up, which finally results in a straight jump. In swimming, synchronous ballistic power strokes of both hindlegs drive the tibiae on a ventral-to-posterior trajectory through the water, well coordinated with the swimming patterns of all legs. In walking, running and climbing the steps of the hindlegs range between 45 deg flexion and 125 deg extension and use non-ballistic, alternating activity of knee flexor and extensor muscles. Steep climbing requires longer bursts from the extensor tibiae muscles when they support the extended hindlegs against gravity forces when the body hangs over. All ballistic movements of cricket knees are elicited by a basic but variable motor pattern: knee flexions by co-contraction of the antagonists prepare catapult extensions with speeds and forces as required in the different behaviours.

The Effect of Patellar Taping on Squat Depth and the Perception of Pain in People with Anterior Knee Pain

PubMed Central

Clifford, Amanda M.; Harrington, Elaine

Patellar taping is a treatment adjunct commonly used in the management of anterior knee pain. The aim of this cross sectional study was to investigate the effects of medial glide patellar taping on sagittal plane lower-limb joint kinematics and knee pain during a unilateral squat in a symptomatic population complaining of anterior knee pain. Ten participants with a history of unilateral or bilateral anterior knee pain were included in the study. Subjects were required to squat on the symptomatic leg under three conditions: placebo tape, patellar tape and no tape. Kinematic data was recorded using the CODA mpx64 motion analysis system and subjects’ pain was assessed using the Numerical Rating Scale. Patellar taping resulted in a significantly greater single-legged squat depth compared to placebo tape (p=0.008) and no tape (p=0.001) and a statistically significant reduction in pain during a squat compared to placebo tape (p=0.001) or no tape (p=0.001). Significant differences were not identified for maximum knee flexion in the patella taping compared to the no tape condition. This study may have significant clinical implications as participants reported less pain and alterations in sagittal plane movement following the application of patellar tape. PMID:24146711

The Anterolateral Capsule of the Knee Behaves Like a Sheet of Fibrous Tissue.

PubMed

Guenther, Daniel; Rahnemai-Azar, Amir A; Bell, Kevin M; Irarrázaval, Sebastián; Fu, Freddie H; Musahl, Volker; Debski, Richard E

2017-03-01

The function of the anterolateral capsule of the knee has not been clearly defined. However, the contribution of this region of the capsule to knee stability in comparison with other anterolateral structures can be determined by the relative force that each structure carries during loading of the knee. Purpose/Hypothesis: The purpose of this study was to determine the forces in the anterolateral structures of the intact and anterior cruciate ligament (ACL)-deficient knee in response to an anterior tibial load and internal tibial torque. It was hypothesized that the anterolateral capsule would not function like a traditional ligament (ie, transmitting forces only along its longitudinal axis). Controlled laboratory study. Loads (134-N anterior tibial load and 7-N·m internal tibial torque) were applied continuously during flexion to 7 fresh-frozen cadaveric knees in the intact and ACL-deficient state using a robotic testing system. The lateral collateral ligament (LCL) and the anterolateral capsule were separated from the surrounding tissue and from each other. This was done by performing 3 vertical incisions: lateral to the LCL, medial to the LCL, and lateral to the Gerdy tubercle. Attachments of the LCL and anterolateral capsule were detached from the underlying tissue (ie, meniscus), leaving the insertions and origins intact. The force distribution in the anterolateral capsule, ACL, and LCL was then determined at 30°, 60°, and 90° of knee flexion using the principle of superposition. In the intact knee, the force in the ACL in response to an anterior tibial load was greater than that in the other structures ( P < .001). However, in response to an internal tibial torque, no significant differences were found between the ACL, LCL, and forces transmitted between each region of the anterolateral capsule after capsule separation. The anterolateral capsule experienced smaller forces (~50% less) compared with the other structures ( P = .048). For the ACL-deficient knee in response to an anterior tibial load, the force transmitted between each region of the anterolateral capsule was 434% greater than was the force in the anterolateral capsule ( P < .001) and 54% greater than the force in the LCL ( P = .036) at 30° of flexion. In response to an internal tibial torque at 30°, 60°, or 90° of knee flexion, no significant differences were found between the force transmitted between each region of the anterolateral capsule and the LCL. The force in the anterolateral capsule was significantly smaller than that in the other structures at all knee flexion angles for both loading conditions ( P = .004 for anterior tibial load and P = .04 for internal tibial torque). The anterolateral capsule carries negligible forces in the longitudinal direction, and the forces transmitted between regions of the capsule were similar to the forces carried by the other structures at the knee, suggesting that it does not function as a traditional ligament. Thus, the anterolateral capsule should be considered a sheet of tissue. Surgical repair techniques for the anterolateral capsule should restore the ability of the tissue to transmit forces between adjacent regions of the capsule rather than along its longitudinal axis.

Radiographic assessment of knee joint rotation.

PubMed Central

Straiton, J A; Todd, B; Venner, R M

1987-01-01

A radiographic technique for measuring conjunct rotation at the knee joint is described. Conjunct rotation was demonstrated to occur over a greater range of values of flexion than conventionally believed. Rotation increased progressively as the knee extended, and was not confined to the last phase of extension. Consideration of such rotatory movement is relevant to the design of knee arthroplasties and also to possible mechanisms of non-bony injury of the knee. PMID:3503049

Comparison of the angles and corresponding moments in the knee and hip during restricted and unrestricted squats.

PubMed

Lorenzetti, Silvio; Gülay, Turgut; Stoop, Mirjam; List, Renate; Gerber, Hans; Schellenberg, Florian; Stüssi, Edgar

2012-10-01

The aim of this study was to compare the angles and corresponding moments in the knee and hip during squats. Twenty subjects performed restricted and unrestricted squats with barbell loads that were 0, ¼, and ½ their body weight. The experimental setup consisted of a motion capture system and 2 force plates. The moments were calculated using inverse dynamics. During the unrestricted squats, the maximum moments in the knee were significantly higher, and those in the hip were significantly lower than during restricted squats. At the lowest position, the maximum knee flexion angles were approximately 86° for the restricted and approximately 106° for the unrestricted techniques, whereas the maximum hip flexion angle was between 95° and 100°. The higher moments in the hip during restricted squats suggest a higher load of the lower back. Athletes who aim to strengthen their quadriceps should consider unrestricted squats because of the larger knee load and smaller back load.

Secondary nerve lengthening to obtain full knee extension in popliteal pterygium syndrome.

PubMed

Boeckx, Willy; Misani, Marta; Vandermeeren, Liesbeth; Franck, Diane; Zirak, Christophe; Demey, Albert

2014-05-01

Microsurgical nerve lengthening was performed in two siblings presenting a popliteal pterigium syndrome with a knee flexion contracture of 80 degrees. After the first attempt for nerve lengthening and knee extension elsewhere, a repeated lengthening was required due to continuing tip-toe walking and recurrent knee contracture at the age of 3 years. An extensive external and internal interfascicular microsurgical neurolysis resulted in a lengthening of the nerves. A full length of leg procedure had to be performed, inclusive of Achilles tendon lengthening to obtain a complete extension of the knee and a 90-degree ankle flexion. Maintaining the leg in a fully extended position was obtained with a dynamic splinting in the first month after the operation. When timing the operation we have to consider the importance of adequate precision of the microsurgical neurolysis, down to the identification of the Fontana bands, and the adequate postoperative splinting. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Is the posterior cruciate ligament necessary for medial pivot knee prostheses with regard to postoperative kinematics?

PubMed

Fang, Chao-Hua; Chang, Chia-Ming; Lai, Yu-Shu; Chen, Wen-Chuan; Song, Da-Yong; McClean, Colin J; Kao, Hao-Yuan; Qu, Tie-Bing; Cheng, Cheng-Kung

2015-11-01

Excellent clinical and kinematical performance is commonly reported after medial pivot knee arthroplasty. However, there is conflicting evidence as to whether the posterior cruciate ligament should be retained. This study simulated how the posterior cruciate ligament, post-cam mechanism and medial tibial insert morphology may affect postoperative kinematics. After the computational intact knee model was validated according to the motion of a normal knee, four TKA models were built based on a medial pivot prosthesis; PS type, modified PS type, CR type with PCL retained and CR type with PCL sacrificed. Anteroposterior translation and axial rotation of femoral condyles on the tibia during 0°-135° knee flexion were analyzed. There was no significant difference in kinematics between the intact knee model and reported data for a normal knee. In all TKA models, normal motion was almost fully restored, except for the CR type with PCL sacrificed. Sacrificing the PCL produced paradoxical anterior femoral translation and tibial external rotation during full flexion. Either the posterior cruciate ligament or post-cam mechanism is necessary for medial pivot prostheses to regain normal kinematics after total knee arthroplasty. The morphology of medial tibial insert was also shown to produce a small but noticeable effect on knee kinematics. V.

Knee stability before and after total and unicondylar knee replacement: in vivo kinematic evaluation utilizing navigation.

PubMed

Casino, Daniela; Martelli, Sandra; Zaffagnini, Stefano; Lopomo, Nicola; Iacono, Francesco; Bignozzi, Simone; Visani, Andrea; Marcacci, Maurilio

2009-02-01

Surgical navigation systems are currently used to guide the surgeon in the correct alignment of the implant. The aim of this study was to expand the use of navigation systems by proposing a surgical protocol for intraoperative kinematics evaluations during knee arthroplasty. The protocol was evaluated on 20 patients, half undergoing unicondylar knee arthroplasty (UKA) and half undergoing posterior-substituting, rotating-platform total knee arthroplasty (TKA). The protocol includes a simple acquisition procedure and an original elaboration methodology. Kinematic tests were performed before and after surgery and included varus/valgus stress at 0 and 30 degrees and passive range of motion. Both UKA and TKA improved varus/valgus stability in extension and preserved the total magnitude of screw-home motion during flexion. Moreover, compared to preoperative conditions, values assumed by tibial axial rotation during flexion in TKA knees were more similar to the rotating patterns of UKA knees. The analysis of the anteroposterior displacement of the knee compartments confirmed that the two prostheses did not produce medial pivoting, but achieved a postoperative normal behavior. These results demonstrated that proposed intraoperative kinematics evaluations by a navigation system provided new information on the functional outcome of the reconstruction useful to restore knee kinematics during surgery.

Radiographic Measurement of Joint Space Width Using the Fixed Flexion View in 1,102 Knees of Japanese Patients with Osteoarthritis in Comparison with the Standing Extended View

PubMed Central

Kan, Hiroyuki; Arai, Yuji; Kobayashi, Masashi; Nakagawa, Shuji; Inoue, Hiroaki; Hino, Manabu; Komaki, Shintaro; Ikoma, Kazuya; Ueshima, Keiichiro; Fujiwara, Hiroyoshi; Kubo, Toshikazu

2017-01-01

Purpose The fixed flexion view (FFV) of the knee is considered useful for evaluating the joint space when assessing the severity of osteoarthritis (OA) of the knee. To clarify the usefulness of FFV for evaluation of the joint space and severity of knee OA, this study evaluated changes in the joint space on the FFV and standing extended view (SEV) in patients with knee OA. Materials and Methods The SEV and FFV images were acquired in 567 patients (1,102 knees) who visited the hospital with a chief complaint of knee joint pain. Medial joint space width (MJSW) and Kellgren-Lawrence (K-L) classification assessed using the SEV and FFV images were compared. Results Mean MJSW was significantly smaller when assessed on the FFV than on the SEV (3.02±1.55 mm vs. 4.31±1.30 mm; p<0.001). The K-L grade was the same or higher on the FFV than on the SEV. Conclusions The FFV is more useful than the SEV for evaluating the joint space in OA knees. Treatment strategies in patients with knee OA should be determined based on routinely acquired FFV images. PMID:28231651

THE INFLUENCE OF HIP STRENGTH ON KNEE KINEMATICS DURING A SINGLE-LEGGED MEDIAL DROP LANDING AMONG COMPETITIVE COLLEGIATE BASKETBALL PLAYERS.

PubMed

Suzuki, Hidetomo; Omori, Go; Uematsu, Daisuke; Nishino, Katsutoshi; Endo, Naoto

2015-10-01

A smaller knee flexion angle and larger knee valgus angle during weight-bearing activities have been identified as risk factors for non-contact anterior cruciate ligament (ACL) injuries. To prevent such injuries, attention has been focused on the role of hip strength in knee motion control. However, gender differences in the relationship between hip strength and knee kinematics during weight-bearing activities in the frontal plane have not been evaluated. The purpose of this study was to determine the influence of hip strength on knee kinematics in both genders during a single-legged landing task in the frontal plane. The hypotheses were that 1) subjects with a greater hip strength would demonstrate larger knee flexion and smaller knee valgus and internal rotation angles and 2) no gender differences would exist during the single-legged landing task. Forty-three Japanese collegiate basketball players (20 males, 23 females) participated in this study. Three-dimensional motion analysis was used to evaluate knee kinematics during a single-legged medial drop landing (SML). A hand-held dynamometer was used to assess hip extensor (HEXT), abductor (HAB), and external rotator (in two positions: seated position [SHER] and prone [PHER]) isometric strength. Spearman rank correlation coefficients (ρ) were determined for correlations between hip strength and knee kinematics at initial contact (IC) and peak (PK) during SML (p < 0.05). Negative correlations were observed between the knee valgus angle at IC and HEXT (ρ = -0.48, p = 0.02), HAB (ρ = -0.46, p = 0.03) and PHER (ρ = -0.44, p = 0.04) strength in females. In addition, a significant positive correlation was observed between the knee flexion angle at PK and HEXT strength (ρ = 0.61, p = 0.004) in males. Significant correlations between hip strength and knee kinematics during SML were observed in both genders. Hip strength may, therefore, play an important role in knee motion control during sports activities, suggesting that increased hip strength may help to prevent non-contact ACL injuries in athletes of both genders. Moreover, gender-specific programs may be needed to control abnormal knee motion, as the influence of hip strength on knee kinematics may differ based on gender. 3.

Effect of partial and complete posterior cruciate ligament transection on medial meniscus: A biomechanical evaluation in a cadaveric model.

PubMed

Gao, Shu-Guang; Zhang, Can; Zhao, Rui-Bo; Liao, Zhan; Li, Yu-Sheng; Yu, Fang; Zeng, Chao; Luo, Wei; Li, Kang-Hua; Lei, Guang-Hua

2013-09-01

The relationship between medial meniscus tear and posterior cruciate ligament (PCL) injury has not been exactly explained. We studied to investigate the biomechanical effect of partial and complete PCL transection on different parts of medial meniscus at different flexion angles under static loading conditions. TWELVE FRESH HUMAN CADAVERIC KNEE SPECIMENS WERE DIVIDED INTO FOUR GROUPS: PCL intact (PCL-I), anterolateral bundle transection (ALB-T), posteromedial bundle transection (PMB-T) and PCL complete transection (PCL-T) group. Strain on the anterior horn, body part and posterior horn of medial meniscus were measured under different axial compressive tibial loads (200-800 N) at 0°, 30°, 60° and 90° knee flexion in each groups respectively. Compared with the PCL-I group, the PCL-T group had a higher strain on whole medial meniscus at 30°, 60° and 90° flexion in all loading conditions and at 0° flexion with 400, 600 and 800 N loads. In ALB-T group, strain on whole meniscus increased at 30°, 60° and 90° flexion under all loading conditions and at 0° flexion with 800 N only. PMB-T exihibited higher strain at 0° flexion with 400 N, 600 N and 800 N, while at 30° and 60° flexion with 800 N and at 90° flexion under all loading conditions. Partial PCL transection triggers strain concentration on medial meniscus and the effect is more pronounced with higher loading conditions at higher flexion angles.

Does high knee flexion cause separation of meniscal repairs?

PubMed

Lin, David L; Ruh, Sarah S; Jones, Hugh L; Karim, Azim; Noble, Philip C; McCulloch, Patrick C

2013-09-01

Previous clinical studies comparing nonrestrictive and restrictive protocols after meniscal repair have shown no difference in outcomes; however, some surgeons still limit range of motion out of concern that it will place undue stress on the repair. Large acute medial meniscal tears will gap during simulated open chain exercises at high flexion angles, and a repaired construct with vertical mattress sutures will not gap. Controlled laboratory study. Tantalum beads were implanted in the medial menisci of 6 fresh-frozen cadaveric knees via an open posteromedial approach. Each knee underwent 10 simulated open chain flexion cycles with loading of the quadriceps and hamstrings. Testing was performed on 3 different states of the meniscus: intact, torn, and repaired. Biplanar radiographs were taken of the loaded knee in 90°, 110°, and 135° of flexion for each state. A 2.5-cm tear was created in the posteromedial meniscus and repaired with inside-out vertical mattress sutures. Displacement of pairs of beads spanning the tear was measured in all planes by use of radiostereometric analysis (RSA) with an accuracy of better than 80 μm. With a longitudinal tear, compression rather than gapping occurred in all 3 regions of the posterior horn of the meniscus (mean ± standard deviation for medial collateral ligament [MCL], -321 ± 320 μm; midposterior, -487 ± 256 μm; root, -318 ± 150 μm) with knee flexion. After repair, meniscal displacement returned part way to intact values in both the MCL (+55 ± 250 μm) and root region (-170 ± 123 μm) but not the midposterior region, where further compression was seen (-661 ± 278 μm). Acute posteromedial meniscal tears and repairs with vertical mattress sutures do not gap, but rather compress in the transverse plane at higher flexion angles when subjected to physiologic loads consistent with active, open kinetic chain range of motion rehabilitation exercises. The kinematics of the repaired meniscus more closely resemble that of the intact meniscus than that of the torn meniscus in regions adjacent to the MCL and the root but not in the midposterior region, where meniscal repair led to increased compression across the tear plane. This study supports the idea that nonrestrictive unresisted open chain range of motion protocols do not place undue stress on meniscal repairs.

Minimal effect of patella eversion on ligament balancing in cruciate-retaining total knee arthroplasty.

PubMed

Aunan, Eirik; Kibsgård, Thomas; Röhrl, Stephan M

2017-03-01

The effect of patellar eversion on ligament laxity measurements is still unclear. The purpose of this study was to investigate the influence of patellar eversion on medial and lateral ligament laxity measurements performed intra-operatively in total knee arthroplasty (TKA). A total of 49 knees (27 female) with mean age 70 years (42-83) and mean body mass index of 28.5 were operated consecutively with a cruciate-retaining prosthesis. Medial and lateral ligament laxity in extension and in 90° of flexion was measured with the spatula-method intra-operatively after implantation of the prosthetic components with the patella everted and thereafter with the patella repositioned. The corresponding changes in gap height and inclination were calculated. A statistically significant increase of 0.6 mm (p < 0.001) in ligament laxity (condylar lift-off) laterally in flexion was found with the patella repositioned compared to everted. No differences were found in extension or medially in flexion. Correspondingly, the flexion gap increased by 0.4 mm (p < 0.001) and the flexion gap inclination increased by 0.6° (p = 0.002) when the patella was repositioned. Earlier research has shown that ligament laxity must be at least 1-2 mm to cause inferior function after TKA. In the current study, we found that the effect of patellar eversion on ligament laxity measurements is too small to be considered clinically relevant. PROSPECTIVE STUDY EVALUATING THE EFFECT OF PATIENT CHARACTERISTICS: Level II.

Influence of trunk posture on lower extremity energetics during running.

PubMed

Teng, Hsiang-Ling; Powers, Christopher M

2015-03-01

This study aimed to examine the influence of sagittal plane trunk posture on lower extremity energetics during running. Forty asymptomatic recreational runners (20 males and 20 females) ran overground at a speed of 3.4 m·s(-1). Sagittal plane trunk kinematics and lower extremity kinematics and energetics during the stance phase of running were computed. Subjects were dichotomized into high flexion (HF) and low flexion (LF) groups on the basis of the mean trunk flexion angle. The mean (±SD) trunk flexion angles of the HF and LF groups were 10.8° ± 2.2° and 3.6° ± 2.8°, respectively. When compared with the LF group, the HF group demonstrated significantly higher hip extensor energy generation (0.12 ± 0.06 vs 0.05 ± 0.04 J·kg(-1), P < 0.001) and lower knee extensor energy absorption (0.60 ± 0.14 vs 0.74 ± 0.09 J·kg(-1), P = 0.001) and generation (0.30 ± 0.05 vs 0.34 ± 0.06 J·kg(-1), P = 0.02). There was no significant group difference for the ankle plantarflexor energy absorption or generation (P > 0.05). Sagittal plane trunk flexion has a significant influence on hip and knee energetics during running. Increasing forward trunk lean during running may be used as a strategy to reduce knee loading without increasing the biomechanical demand at the ankle plantarflexors.

Temporal gene expression profiling of the rat knee joint capsule during immobilization-induced joint contractures.

PubMed

Wong, Kayleigh; Sun, Fangui; Trudel, Guy; Sebastiani, Paola; Laneuville, Odette

2015-05-26

Contractures of the knee joint cause disability and handicap. Recovering range of motion is recognized by arthritic patients as their preference for improved health outcome secondary only to pain management. Clinical and experimental studies provide evidence that the posterior knee capsule prevents the knee from achieving full extension. This study was undertaken to investigate the dynamic changes of the joint capsule transcriptome during the progression of knee joint contractures induced by immobilization. We performed a microarray analysis of genes expressed in the posterior knee joint capsule following induction of a flexion contracture by rigidly immobilizing the rat knee joint over a time-course of 16 weeks. Fold changes of expression values were measured and co-expressed genes were identified by clustering based on time-series analysis. Genes associated with immobilization were further analyzed to reveal pathways and biological significance and validated by immunohistochemistry on sagittal sections of knee joints. Changes in expression with a minimum of 1.5 fold changes were dominated by a decrease in expression for 7732 probe sets occurring at week 8 while the expression of 2251 probe sets increased. Clusters of genes with similar profiles of expression included a total of 162 genes displaying at least a 2 fold change compared to week 1. Functional analysis revealed ontology categories corresponding to triglyceride metabolism, extracellular matrix and muscle contraction. The altered expression of selected genes involved in the triglyceride biosynthesis pathway; AGPAT-9, and of the genes P4HB and HSP47, both involved in collagen synthesis, was confirmed by immunohistochemistry. Gene expression in the knee joint capsule was sensitive to joint immobility and provided insights into molecular mechanisms relevant to the pathophysiology of knee flexion contractures. Capsule responses to immobilization was dynamic and characterized by modulation of at least three reaction pathways; down regulation of triglyceride biosynthesis, alteration of extracellular matrix degradation and muscle contraction gene expression. The posterior knee capsule may deploy tissue-specific patterns of mRNA regulatory responses to immobilization. The identification of altered expression of genes and biochemical pathways in the joint capsule provides potential targets for the therapy of knee flexion contractures.

Anteroposterior translation and range of motion after total knee arthroplasty using posterior cruciate ligament-retaining versus posterior cruciate ligament-substituting prostheses.

PubMed

Ishii, Yoshinori; Noguchi, Hideo; Sato, Junko; Sakurai, Tetsuya; Toyabe, Shin-Ichi

2017-11-01

It is still controversial whether anteroposterior (AP) translation magnitude after total knee arthroplasty (TKA) affects clinical outcomes, particularly range of motion (ROM). This study examined the following two questions: (1) are AP translations at the mid- and long-term follow-up different for knees within the same patient treated with posterior cruciate ligament-retaining (PCLR) versus posterior cruciate ligament-substituting (PCLS) mobile-bearing TKA prosthesis designs? (2) Is the ROM at the mid- and long-term follow-up for knees treated with PCLR and PCLS designs correlated with the AP translation? Thirty-seven patients undergoing sequential bilateral TKA for osteoarthritis were prospectively enrolled. Patients received a PCLR implant in one knee and a PCLS implant in the other and were followed-up for an average 9.8 ± 3.2 years. The AP translations at 30° and 75° of knee flexion and the ROM of both knees were assessed. The implant design (p < 0.001), but not flexion angle (n.s.), had a significant effect on AP translation. AP translation values were larger in PCLR knees than in PCLS knees at both flexion angles (p < 0.0001). The ROM at the final follow-up in the two implant designs was similar (both 115°, n.s.). There was a weak correlation between ROM and AP translation at 30° in the PCLR knees (r = 0.397, p = 0.015), but no correlation at 75° or in the PCLS knees. Differently constrained prosthesis designs resulted in significantly different AP translational values within the same patient. This indicates that achieving good clinical outcomes and ROM after TKA may not be strongly influenced by the specifics of each patient's anatomical characteristics, but instead by knee constrainment. Clinically, this means that surgeons should familiarize themselves with the AP translation of the implant being used, as this may be the most important factor for optimizing outcomes after mobile-bearing TKA. Level of evidence II, prospective, comparative study.

The effects of military body armour on the lower back and knee mechanics during toe-touch and two-legged squat tasks.

PubMed

Phillips, Megan; Bazrgari, Babak; Shapiro, Robert

2015-01-01

While effective in the prevention of otherwise lethal injuries, military body armour (BA) has been suggested to reduce warfighter's performance and increase injury-related musculoskeletal conditions. Providing the significant role of joint biomechanics in both performance and risk of injury, the immediate and prolonged effects of wearing BA on biomechanics of the lower back and knee during toe-touch (TT) and two-legged squat (TLS) tasks were investigated. The immediate effects of BA were an increase of >40 ms (p ≤ 0.02) in flexion duration of the dominant joint and an ∼1 s (p ≤ 0.02) increase in overall task duration as well as an ∼18% (p = 0.03) decrease in the lumbopelvic rhythm ratio near the mid-range of trunk flexion. In general the prolonged duration of wearing BA (i.e. 45 min of walking) was not found to cause more changes in our measures than walking without BA. The effects of wearing military BA on biomechanics of the lower back and knee during TT and TLS tasks were investigated. The immediate effects of BA were increased flexion duration, increased overall trial duration and decreased lumbopelvic rhythm near the mid-range of trunk flexion.

A Maximum Muscle Strength Prediction Formula Using Theoretical Grade 3 Muscle Strength Value in Daniels et al.'s Manual Muscle Test, in Consideration of Age: An Investigation of Hip and Knee Joint Flexion and Extension.

PubMed

Usa, Hideyuki; Matsumura, Masashi; Ichikawa, Kazuna; Takei, Hitoshi

2017-01-01

This study attempted to develop a formula for predicting maximum muscle strength value for young, middle-aged, and elderly adults using theoretical Grade 3 muscle strength value (moment fair: M f )-the static muscular moment to support a limb segment against gravity-from the manual muscle test by Daniels et al. A total of 130 healthy Japanese individuals divided by age group performed isometric muscle contractions at maximum effort for various movements of hip joint flexion and extension and knee joint flexion and extension, and the accompanying resisting force was measured and maximum muscle strength value (moment max, M m ) was calculated. Body weight and limb segment length (thigh and lower leg length) were measured, and M f was calculated using anthropometric measures and theoretical calculation. There was a linear correlation between M f and M m in each of the four movement types in all groups, excepting knee flexion in elderly. However, the formula for predicting maximum muscle strength was not sufficiently compatible in middle-aged and elderly adults, suggesting that the formula obtained in this study is applicable in young adults only.

Relationships among range of motion, functional mobility, and quality of life in children and adolescents after limb-sparing surgery for lower-extremity sarcoma.

PubMed

Marchese, Victoria G; Spearing, Elena; Callaway, Lulie; Rai, Shesh N; Zhang, Lijun; Hinds, Pamela S; Carlson, Claire A; Neel, Michael D; Rao, Bhaskar N; Ginsberg, Jill

2006-01-01

The study was designed to examine relationships between range of motion (ROM), functional mobility, and quality of life (QL) in patients with lower-extremity sarcoma (LES) after limb-sparing surgery Sixty-eight patients with LES (age, 10-26 years) participated. The patients performed hip flexion, hip extension, knee flexion, and knee extension, Timed Up and Down Stairs (TUDS), Timed Up and Go (TUG), nine-minute run-walk (9-min), and completed the QL measure, Short-Form-36 version two (SF-36v2). Significant correlations (p < 0.01) were found between hip extension and SF-36v2 physical component scale (PCS; r = 0.33), TUDS (r = -0.32), TUG (r = -0.33); hip flexion and TUDS (r = -0.31), TUG (r = -0.39), 9-min (r = 0.44); knee flexion and TUDS (r = -0.52), TUG (r = -0.40), 9-min (r = 0.37); SF-36v2 PCS and TUDS (r = -0.56), TUG (r = -0.51), 9-min (r = 0.60). ROM correlates with functional mobility and QL in patients with LES after limb-sparing surgery. ROM exercises are important component of a physical therapy program for children and adolescents with LES.

Effects of combined linear and nonlinear periodic training on physical fitness and competition times in finswimmers.

PubMed

Yu, Kyung-Hun; Suk, Min-Hwa; Kang, Shin-Woo; Shin, Yun-A

2014-10-01

The purpose of this study was to investigate the effect of combined linear and nonlinear periodic training on physical fitness and competition times in finswimmers. The linear resistance training model (6 days/week) and nonlinear underwater training (4 days/week) were applied to 12 finswimmers (age, 16.08± 1.44 yr; career, 3.78± 1.90 yr) for 12 weeks. Body composition measures included weight, body mass index (BMI), percent fat, and fat-free mass. Physical fitness measures included trunk flexion forward, trunk extension backward, sargent jump, 1-repetition-maximum (1 RM) squat, 1 RM dead lift, knee extension, knee flexion, trunk extension, trunk flexion, and competition times. Body composition and physical fitness were improved after the 12-week periodic training program. Weight, BMI, and percent fat were significantly decreased, and trunk flexion forward, trunk extension backward, sargent jump, 1 RM squat, 1 RM dead lift, and knee extension (right) were significantly increased. The 50- and 100-m times significantly decreased in all 12 athletes. After 12 weeks of training, all finswimmers who participated in this study improved their times in a public competition. These data indicate that combined linear and nonlinear periodic training enhanced the physical fitness and competition times in finswimmers.

A Maximum Muscle Strength Prediction Formula Using Theoretical Grade 3 Muscle Strength Value in Daniels et al.'s Manual Muscle Test, in Consideration of Age: An Investigation of Hip and Knee Joint Flexion and Extension

PubMed Central

Matsumura, Masashi; Ichikawa, Kazuna; Takei, Hitoshi

2017-01-01

This study attempted to develop a formula for predicting maximum muscle strength value for young, middle-aged, and elderly adults using theoretical Grade 3 muscle strength value (moment fair: Mf)—the static muscular moment to support a limb segment against gravity—from the manual muscle test by Daniels et al. A total of 130 healthy Japanese individuals divided by age group performed isometric muscle contractions at maximum effort for various movements of hip joint flexion and extension and knee joint flexion and extension, and the accompanying resisting force was measured and maximum muscle strength value (moment max, Mm) was calculated. Body weight and limb segment length (thigh and lower leg length) were measured, and Mf was calculated using anthropometric measures and theoretical calculation. There was a linear correlation between Mf and Mm in each of the four movement types in all groups, excepting knee flexion in elderly. However, the formula for predicting maximum muscle strength was not sufficiently compatible in middle-aged and elderly adults, suggesting that the formula obtained in this study is applicable in young adults only. PMID:28133549

Dynamic Simulation and Analysis of Human Walking Mechanism

NASA Astrophysics Data System (ADS)

Azahari, Athirah; Siswanto, W. A.; Ngali, M. Z.; Salleh, S. Md.; Yusup, Eliza M.

2017-01-01

Behaviour such as gait or posture may affect a person with the physiological condition during daily activities. The characteristic of human gait cycle phase is one of the important parameter which used to described the human movement whether it is in normal gait or abnormal gait. This research investigates four types of crouch walking (upright, interpolated, crouched and severe) by simulation approach. The assessment are conducting by looking the parameters of hamstring muscle joint, knee joint and ankle joint. The analysis results show that based on gait analysis approach, the crouch walking have a weak pattern of walking and postures. Short hamstring and knee joint is the most influence factor contributing to the crouch walking due to excessive hip flexion that typically accompanies knee flexion.

Male and female runners demonstrate different sagittal plane mechanics as a function of static hamstring flexibility.

PubMed

Williams, D S Blaise; Welch, Lee M

2015-01-01

Injuries to runners are common. However, there are many potential contributing factors to injury. While lack of flexibility alone is commonly related to injury, there are clear differences in hamstring flexibility between males and females. To compare the effect of static hamstring length on sagittal plane mechanics between male and female runners. Forty subjects (30.0±6.4 years) participated and were placed in one of 4 groups: flexible males (n=10), inflexible males (n=10), flexible females (n=10), and inflexible females (n=10). All subjects were free of injury at the time of data collection. Three-dimensional kinematics and kinetics were collected while subjects ran over ground across 2 force platforms. Sagittal plane joint angles and moments were calculated at the knee and hip and compared with a 2-way (sex X flexibility) ANOVA (α=0.05). Males exhibited greater peak knee extension moment than females (M=2.80±0.47, F=2.48±0.52 Nm/kg*m, p=0.05) and inflexible runners exhibited greater peak knee extension moment than flexible runners (In=2.83±0.56, Fl=2.44±0.51 Nm/kg*m, p=0.01). For hip flexion at initial contact, a significant interaction existed (p<0.05). Flexible females (36.7±7.4º) exhibited more hip flexion than inflexible females (27.9±4.6º, p<0.01) and flexible males (30.1±9.5º, p<0.05). No differences existed for knee angle at initial contact, peak knee angle, peak hip angle, or peak hip moment. Hamstring flexibility results in different mechanical profiles in males and females. Flexibility in the hamstrings may result in decreased moments via active or passive tension. These differences may have implications for performance and injury in flexible female runners.

Male and female runners demonstrate different sagittal plane mechanics as a function of static hamstring flexibility

PubMed Central

Williams III, D. S. Blaise; Welch, Lee M.

2015-01-01

ABSTRACT Background: Injuries to runners are common. However, there are many potential contributing factors to injury. While lack of flexibility alone is commonly related to injury, there are clear differences in hamstring flexibility between males and females. Objective: To compare the effect of static hamstring length on sagittal plane mechanics between male and female runners. Method: Forty subjects (30.0±6.4 years) participated and were placed in one of 4 groups: flexible males (n=10), inflexible males (n=10), flexible females (n=10), and inflexible females (n=10). All subjects were free of injury at the time of data collection. Three-dimensional kinematics and kinetics were collected while subjects ran over ground across 2 force platforms. Sagittal plane joint angles and moments were calculated at the knee and hip and compared with a 2-way (sex X flexibility) ANOVA (α=0.05). Results: Males exhibited greater peak knee extension moment than females (M=2.80±0.47, F=2.48±0.52 Nm/kg*m, p=0.05) and inflexible runners exhibited greater peak knee extension moment than flexible runners (In=2.83±0.56, Fl=2.44±0.51 Nm/kg*m, p=0.01). For hip flexion at initial contact, a significant interaction existed (p<0.05). Flexible females (36.7±7.4º) exhibited more hip flexion than inflexible females (27.9±4.6º, p<0.01) and flexible males (30.1±9.5º, p<0.05). No differences existed for knee angle at initial contact, peak knee angle, peak hip angle, or peak hip moment. Conclusion: Hamstring flexibility results in different mechanical profiles in males and females. Flexibility in the hamstrings may result in decreased moments via active or passive tension. These differences may have implications for performance and injury in flexible female runners. PMID:26537812

Adolescent Body Size and Flexibility

ERIC Educational Resources Information Center

Krahenbuhl, Gary S.; Martin, Stephen L.

1977-01-01

Research suggests that differences in body surface area that occur during adolescence are significantly negatively related to knee, hip, and shoulder flexion-extension range, with flexibility decreasing as body surface area increases, with the relationship strongest for the knee. (MJB)

The physiological cost index of walking with a powered knee-ankle-foot orthosis in subjects with poliomyelitis: A pilot study.

PubMed

Arazpour, Mokhtar; Ahmadi Bani, Monireh; Samadian, Mohammad; Mousavi, Mohammad E; Hutchins, Stephen W; Bahramizadeh, Mahmood; Curran, Sarah; Mardani, Mohammad A

2016-08-01

A powered knee-ankle-foot orthosis was developed to provide restriction of knee flexion during stance phase and active flexion and extension of the knee during swing phase of gait. The purpose of this study was to determine its effect on the physiological cost index, walking speed and the distance walked in people with poliomyelitis compared to when walking with a knee-ankle-foot orthosis with drop lock knee joints. Quasi experimental study. Seven subjects with poliomyelitis volunteered for the study and undertook gait analysis with both types of knee-ankle-foot orthosis. Walking with the powered knee-ankle-foot orthosis significantly reduced walking speed (p = 0.015) and the distance walked (p = 0.004), and also, it did not improve physiological cost index values (p = 0.009) compared to walking with the locked knee-ankle-foot orthosis. Using a powered knee-ankle-foot orthosis did not significantly improve any of the primary outcome measures during walking for poliomyelitis subjects. This powered knee-ankle-foot orthosis design did not improve the physiological cost index of walking for people with poliomyelitis when compared to walking with a knee-ankle-foot orthosis with drop lock knee joints. This may have been due to the short training period used or the bulky design and additional weight of the powered orthosis. Further research is therefore warranted. © The International Society for Prosthetics and Orthotics 2015.

Use of the dual force system to correct chronic knee deformities due to severe haemophilia.

PubMed

Kale, J S; Ghosh, K; Mohanty, D; Pathare, A V; Jijina, F

2000-05-01

In this study, the use of the dual force system to correct recent or relatively longstanding knee deformities in ten patients is described. (Nine of the patients had severe haemophilia and one had severe von Willebrand's disease.) The mean duration of deformity in these patients was 10 months. The mean range of movement at the affected knee joints increased from 50 degrees at pre-intervention to 110 degrees following 6 weeks of application of the dual force system. In nine of ten patients (90%) the residual flexion deformity ranged from 0 degrees to 10 degrees. The dual force system offers an easily affordable and effective means of correcting a flexion deformity of the knee joint in severely affected haemophilia and allied disorders. More extensive use of this technique in different centres is required to determine its place in the day-to-day management of such patients.

Does Kinematic Alignment and Flexion of a Femoral Component Designed for Mechanical Alignment Reduce the Proximal and Lateral Reach of the Trochlea?

PubMed

Brar, Abheetinder S; Howell, Stephen M; Hull, Maury L; Mahfouz, Mohamed R

2016-08-01

Kinematically aligned total knee arthroplasty uses a femoral component designed for mechanical alignment (MA) and sets the component in more internal, valgus, and flexion rotation than MA. It is unknown how much kinematic alignment (KA) and flexion of the femoral component reduce the proximal and lateral reach of the trochlea; two reductions that could increase the risk of abnormal patella tracking. We simulated MA and KA of the femoral component in 0° of flexion on 20 3-dimensional bone models of normal femurs. The mechanically and kinematically aligned components were then aligned in 5°, 10°, and 15° of flexion and downsized until the flange contacted the anterior femur. The reductions in the proximal and lateral reach from the proximal point of the trochlea of the MA component set in 0° of flexion were computed. KA at 0° of flexion did not reduce the proximal reach and reduced the lateral reach an average of 3 mm. Flexion of the MA and KA femoral component 5°, 10°, and 15° reduced the proximal reach an average of 4 mm, 8 mm, and 12 mm, respectively (0.8 mm/degree of flexion), and reduced the lateral reach an average of 1 mm and 4 mm regardless of the degree of flexion, respectively. Arthroplasty surgeons and biomechanical engineers striving to optimize patella tracking might consider developing surgical techniques to minimize flexion of the femoral component when performing KA and MA total knee arthroplasty to promote early patella engagement and consider designing a femoral component with a trochlea shaped specifically for KA. Copyright © 2016 Elsevier Inc. All rights reserved.

Customized versus Patient-Sized Cruciate-Retaining Total Knee Arthroplasty: An In Vivo Kinematics Study Using Mobile Fluoroscopy.

PubMed

Zeller, Ian M; Sharma, Adrija; Kurtz, William B; Anderle, Mathew R; Komistek, Richard D

2017-04-01

Historically, knee arthroplasties have been designed using average patient anatomy. Recent advances in imaging and manufacturing have facilitated the development of customized prostheses designed to fit the unique shape of individual patients. The purpose of this study is to determine if improving implant design through customized total knee arthroplasty (TKA) improves kinematic function. Using state-of-the-art mobile fluoroscopy, tibiofemoral kinematics were analyzed for 24 subjects with a customized individually made (CIM), cruciate-retaining TKA, and 14 subjects having an asymmetric condylar cruciate-retaining TKA. Subjects performed a weight-bearing deep knee bend and a rise from a seated position. Each patient was evaluated for weight-bearing range of motion, femorotibial translation, femorotibial axial rotation, and condylar liftoff occurrence. Subjects having a CIM TKA experienced greater weight-bearing knee flexion compared with the traditional posterior cruciate-retaining (PCR) TKA design. During flexion, the CIM TKA subjects consistently exhibited more posterior femoral rollback than the traditional PCR TKA subjects. The CIM TKA was found to have statistically greater axial rotation compared with the traditional PCR TKA (P = .05). Of note, only the CIM TKA patients experienced femoral internal rotation at full extension, as exhibited in a normal knee. Compared with the traditional PCR TKA, the CIM TKAs demonstrated minimal occurrences of paradoxical sliding and reverse rotation during flexion and extension. The CIM TKA subjects showed minimal liftoff and hence better stability in earlyflexion to midflexion compared with the traditional PCR subjects. The CIM TKA demonstrated kinematics more similar to a normal knee. Therefore, using customized implant technology through CIM TKA designs affords benefits including more normal motion compared with a traditional PCR TKA. Copyright © 2016 Elsevier Inc. All rights reserved.

Biomechanics of Hyperflexion and Kneeling before and after Total Knee Arthroplasty

PubMed Central

2014-01-01

The capacity to perform certain activities is frequently compromised after total knee arthroplasty (TKA) due to a functional decline resulting from decreased range of motion and a diminished ability to kneel. In this manuscript, the current biomechanical understanding of hyperflexion and kneeling before and after TKA will be discussed. Patellofemoral and tibiofemoral joint contact area, contact pressure, and kinematics were evaluated in cadaveric studies using a Tekscan pressure measuring system and Microscribe. Testing was performed on intact knees and following cruciate retaining and posterior stabilized TKA at knee flexion angles of 90°, 105°, 120°, and 135°. Three loading conditions were used to simulate squatting, double stance kneeling, and single stance kneeling. Following TKA with double stance kneeling, patellofemoral contact areas did not increase significantly at high knee flexion angle (135°). Kneeling resulted in tibial posterior translation and external rotation at all flexion angles. Moving from double to single stance kneeling tended to increase pressures in the cruciate retaining group, but decreased pressures in the posterior stabilized group. The cruciate retaining group had significantly larger contact areas than the posterior stabilized group, although no significant differences in pressures were observed comparing the two TKA designs (p < 0.05). If greater than 120° of postoperative knee range of motion can be achieved following TKA, then kneeling may be performed with less risk in the patellofemoral joint than was previously believed to be the case. However, kneeling may increase the likelihood of damage to cartilage and menisci in intact knees and after TKA increases in tibiofemoral contact area and pressures may lead to polyethyelene wear if performed on a chronic, repetitive basis. PMID:24900891

Biomechanics of hyperflexion and kneeling before and after total knee arthroplasty.

PubMed

Lee, Thay Q

2014-06-01

The capacity to perform certain activities is frequently compromised after total knee arthroplasty (TKA) due to a functional decline resulting from decreased range of motion and a diminished ability to kneel. In this manuscript, the current biomechanical understanding of hyperflexion and kneeling before and after TKA will be discussed. Patellofemoral and tibiofemoral joint contact area, contact pressure, and kinematics were evaluated in cadaveric studies using a Tekscan pressure measuring system and Microscribe. Testing was performed on intact knees and following cruciate retaining and posterior stabilized TKA at knee flexion angles of 90°, 105°, 120°, and 135°. Three loading conditions were used to simulate squatting, double stance kneeling, and single stance kneeling. Following TKA with double stance kneeling, patellofemoral contact areas did not increase significantly at high knee flexion angle (135°). Kneeling resulted in tibial posterior translation and external rotation at all flexion angles. Moving from double to single stance kneeling tended to increase pressures in the cruciate retaining group, but decreased pressures in the posterior stabilized group. The cruciate retaining group had significantly larger contact areas than the posterior stabilized group, although no significant differences in pressures were observed comparing the two TKA designs (p < 0.05). If greater than 120° of postoperative knee range of motion can be achieved following TKA, then kneeling may be performed with less risk in the patellofemoral joint than was previously believed to be the case. However, kneeling may increase the likelihood of damage to cartilage and menisci in intact knees and after TKA increases in tibiofemoral contact area and pressures may lead to polyethyelene wear if performed on a chronic, repetitive basis.

Anterior cruciate ligament reconstruction and cartilage contact forces--A 3D computational simulation.

PubMed

Wang, Lianxin; Lin, Lin; Feng, Yong; Fernandes, Tiago Lazzaretti; Asnis, Peter; Hosseini, Ali; Li, Guoan

2015-12-01

Clinical outcome studies showed a high incidence of knee osteoarthritis after anterior cruciate ligament reconstruction. Abnormal joint kinematics and loading conditions were assumed as risking factors. However, little is known on cartilage contact forces after the surgery. A validated computational model was used to simulate anatomic and transtibial single-bundle anterior cruciate ligament reconstructions. Two graft fixation angles (0° and 30°) were simulated for each reconstruction. Biomechanics of the knee was investigated in intact, anterior cruciate ligament deficient and reconstructed conditions when the knee was subjected to 134 N anterior load and 400 N quadriceps load at 0°, 30°, 60° and 90° of flexion. The tibial translation and rotation, graft forces, medial and lateral contact forces were calculated. When the graft was fixed at 0°, the anatomic reconstruction resulted in slightly larger lateral contact force at 0° compared to the intact knee while the transtibial technique led to higher contact force at both 0° and 30° under the muscle load. When graft was fixed at 30°, the anatomic reconstruction overstrained the knee at 0° with larger contact forces, while the transtibial technique resulted in slightly larger contact forces at 30°. This study suggests that neither the anatomic nor the transtibial reconstruction can consistently restore normal knee biomechanics at different flexion angles. The anatomic reconstruction may better restore anteroposterior stability and contact force with the graft fixed at 0°. The transtibial technique may better restore knee anteroposterior stability and articular contact force with the graft fixed at 30° of flexion. Copyright © 2015 Elsevier Ltd. All rights reserved.

Reciprocal activation of gastrocnemius and soleus motor units is associated with fascicle length change during knee flexion.

PubMed

Lauber, Benedikt; Lichtwark, Glen A; Cresswell, Andrew G

2014-06-01

While medial gastrocnemius (MG) and soleus (SOL) are considered synergists, they are anatomically exclusive in that SOL crosses only the ankle, while MG crosses both the knee and ankle. Due to the force-length properties of both active and passive structures, activation of SOL and MG must be constantly regulated to provide the required joint torques for any planned movement. As such, the aim of this study was to investigate the neural regulation of MG and SOL when independently changing their length by changing only the knee joint angle, thus exclusively altering the length of MG fibers. MG and SOL motor units (MU) were recorded intramuscularly along with ultrasound imaging of MG and SOL fascicle lengths, while moving the knee through 60° of rotation and maintaining a low level of voluntary plantar flexor torque. The results showed a reciprocal activation of MG and SOL as the knee was moved into flexion and extension. A clear reduction in MG MU firing rates occurred as the knee was flexed (MG fascicles shortening), with de-recruitment of most MG MU occurring at close to full knee flexion. A concomitant increase in SOL MU activity was observed while no change in the length of its fascicles was found. The opposite effects were found when the knee was moved into extension. A strong correlation (ICC = 0.78) was found between the fascicle length at which MG MUs were de-recruited and subsequently re-recruited. This was stronger than the relationship of de-recruitment and re-recruitment with knee angle (ICC = 0.52), indicating that in this instance, muscle fascicle length rather than joint angle is more influential in regulating MG recruitment. Such a reciprocal arrangement like the one presented here for SOL and MG is essential for human voluntary movements such as walking or cycling. © 2014 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Brief communication: Hip joint mobility in free-ranging rhesus macaques

PubMed Central

Hammond, Ashley S.; Johnson, Victoria P.; Higham, James P.

2016-01-01

Objectives We aimed to test for differences in hip joint range of motion (ROM) between captive and free-ranging rhesus macaques (Macaca mulatta), particularly for hip joint abduction, which previous studies of captive macaques have found to be lower than predicted. Materials and Methods Hip ROM was assessed following standard joint measurement methodology in anesthetized adult free-ranging rhesus macaques (n=39) from Cayo Santiago, and compared to published ROM data from captive rhesus macaques (n=16) (Hammond 2014a, American Journal of Physical Anthropology). Significant differences between populations were detected using one-way analysis of variance (p<0.05). Results In a sample of pooled sexes and ages, free-ranging macaques are capable of increased hip abduction, flexion, and internal rotation compared to captive individuals. These differences in joint excursion resulted in free-ranging individuals having significantly increased ROM for hip adduction-abduction, rotation, flexion-extension, and the distance spanned by the knee during hip abduction. When looking at data for a smaller sample of age-matched males, fewer ROM differences are significant, but free-ranging males have significantly increased hip abduction, internal rotation, range of flexion-extension, and distance spanned by the knee during hip abduction compared to captive males of similar age. Discussion Our results suggest that a spatially restrictive environment results in decreased hip mobility in cage-confined animals and ultimately limits the potential limb postures in captive macaques. These results have implications for selection of animal samples in model validation studies, as well as laboratory animal husbandry practices. PMID:27731892

Kinematics of Different Components of the Posterolateral Corner of the Knee in the Lateral Collateral Ligament-intact State: A Human Cadaveric Study.

PubMed

Domnick, Christoph; Frosch, Karl-Heinz; Raschke, Michael J; Vogel, Nils; Schulze, Martin; von Glahn, Mathias; Drenck, Tobias C; Herbort, Mirco

2017-10-01

To determine the static stabilizing effects of different anatomical structures of the posterolateral corner (PLC) of the knee in the lateral collateral ligament (LCL)-intact state. Thirteen fresh-frozen human cadaveric knees were dissected and tested using an industrial robot with an optical tracking system. Kinematics were determined for 134 N anterior/posterior loads, 10 N m valgus/varus loads, and 5 N m internal/external rotatory loads in 0°, 20°, 30°, 60°, and 90° of knee flexion. The PLC structures were dissected and consecutively released: (I) intact knee joint, (II) with released posterior cruciate ligament (PCL), (III) popliteomeniscal fibers, (IV) popliteofibular ligament, (V) arcuat and popliteotibial fibers, (VI) popliteus tendon (PLT), and (VII) LCL. Repeated-measures analysis of variance was performed with significance set at P < .05. After releasing the PCL, posterior tibial translation increased by 5.2 mm at 20° to 9.4 mm at 90° of joint flexion (P < .0001). A mild 1.8° varus instability was measured in 0° of flexion (P = .0017). After releasing the PLC structures, posterior tibial translation further increased by 2.9 mm at 20° to 5.9 mm at 90° of flexion (P < .05) and external rotation angle increased by 2.6° at 0° to 7.9° at 90° of flexion (P < .05, vs II). Varus stability did not decrease. Mild differences between states V and VI were found in 60° and 90° external rotation tests (2.1° and 3.1°; P < .05). The connecting ligaments/fibers to the PLT act as a primary static stabilizer against external rotatory loads and a secondary stabilizer against posterior tibial loads (when PCL is injured). After releasing these structures, most static stabilizing function of the intact PLT is lost. The PLC has no varus-stabilizing function in the LCL-intact knee. Anatomy and function of these structures for primary and secondary joint stability should be considered for clinical diagnostics and when performing surgery in the PLC. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Loading Patterns of the Posterior Cruciate Ligament in the Healthy Knee: A Systematic Review

PubMed Central

List, Renate; Oberhofer, Katja; Fucentese, Sandro F.; Snedeker, Jess G.; Taylor, William R.

2016-01-01

Background The posterior cruciate ligament (PCL) is the strongest ligament of the knee, serving as one of the major passive stabilizers of the tibio-femoral joint. However, despite a number of experimental and modelling approaches to understand the kinematics and kinetics of the ligament, the normal loading conditions of the PCL and its functional bundles are still controversially discussed. Objectives This study aimed to generate science-based evidence for understanding the functional loading of the PCL, including the anterolateral and posteromedial bundles, in the healthy knee joint through systematic review and statistical analysis of the literature. Data sources MEDLINE, EMBASE and CENTRAL Eligibility criteria for selecting studies Databases were searched for articles containing any numerical strain or force data on the healthy PCL and its functional bundles. Studied activities were as follows: passive flexion, flexion under 100N and 134N posterior tibial load, walking, stair ascent and descent, body-weight squatting and forward lunge. Method Statistical analysis was performed on the reported load data, which was weighted according to the number of knees tested to extract average strain and force trends of the PCL and identify deviations from the norms. Results From the 3577 articles retrieved by the initial electronic search, only 66 met all inclusion criteria. The results obtained by aggregating data reported in the eligible studies indicate that the loading patterns of the PCL vary with activity type, knee flexion angle, but importantly also the technique used for assessment. Moreover, different fibres of the PCL exhibit different strain patterns during knee flexion, with higher strain magnitudes reported in the anterolateral bundle. While during passive flexion the posteromedial bundle is either lax or very slightly elongated, it experiences higher strain levels during forward lunge and has a synergetic relationship with the anterolateral bundle. The strain patterns obtained for virtual fibres that connect the origin and insertion of the bundles in a straight line show similar trends to those of the real bundles but with different magnitudes. Conclusion This review represents what is now the best available understanding of the biomechanics of the PCL, and may help to improve programs for injury prevention, diagnosis methods as well as reconstruction and rehabilitation techniques. PMID:27880849

Navigation-based tibial rotation at 90° of flexion is associated with better range of motion in navigated total knee arthroplasty.

PubMed

Ishida, Kazunari; Shibanuma, Nao; Matsumoto, Tomoyuki; Sasaki, Hiroshi; Takayama, Koji; Hiroshima, Yuji; Kuroda, Ryosuke; Kurosaka, Masahiro

2016-08-01

In clinical practice, people with better femorotibial rotation in the flexed position often achieve a favourable postoperative maximum flexion angle (MFA). However, no objective data have been reported to support this clinical observation. In the present study, we aimed to investigate the correlation between the amount of intraoperative rotation and the pre- and postoperative flexion angles. Fifty-five patients with varus osteoarthritis undergoing computer-assisted posterior-stabilized total knee arthroplasty (TKA) were enrolled. After registration, rotational stress was applied towards the knee joint, and the rotational angles were recorded by using a navigation system at maximum extension and 90° of flexion. After implantation, rotational stress was applied for a second time, and the angles were recorded once more. The MFA was measured before surgery and 1 month after surgery, and the correlation between the amount of femorotibial rotation during surgery and the MFA was statistically evaluated. Although the amount of tibial rotation at maximum extension was not correlated with the MFA, the amount of tibial rotation at 90° of flexion after registration was positively correlated with the pre- and postoperative MFA (both p < 0.005). However, no significant relationship was observed between the amount of tibial rotation after implantation and the postoperative MFA (n.s.). The results showed that better femorotibial rotation at 90° of flexion is associated with a favourable postoperative MFA, suggesting that the flexibility of the surrounding soft tissues is an important factor for obtaining a better MFA, which has important clinical relevance. Hence, further evaluation of navigation-based kinematics during TKA may provide useful information on MFA. Diagnostic studies, development of diagnostic criteria in a consecutive series of patients, and a universally applied "gold" standard, Level II.

The Influence of Joint Distraction Force on the Soft-Tissue Balance Using Modified Gap-Balancing Technique in Posterior-Stabilized Total Knee Arthroplasty.

PubMed

Nagai, Kanto; Muratsu, Hirotsugu; Takeoka, Yoshiki; Tsubosaka, Masanori; Kuroda, Ryosuke; Matsumoto, Tomoyuki

2017-10-01

During modified gap-balancing technique, there is no consensus on the best method for obtaining appropriate soft-tissue balance and determining the femoral component rotation. Sixty-five varus osteoarthritic patients underwent primary posterior-stabilized total knee arthroplasty using modified gap-balancing technique. The influence of joint distraction force on the soft-tissue balance measurement during the modified gap-balancing technique was evaluated with Offset Repo-Tensor between the osteotomized surfaces at extension, and between femoral posterior condyles and tibial osteotomized surface at flexion of the knee before the resection of femoral posterior condyles. The joint center gap (millimeters) and varus ligament balance (°) were measured under 20, 40, and 60 pounds of joint distraction forces, and the differences in these values at extension and flexion (the value at flexion minus the value at extension) were also calculated. The differences in joint center gap (-6.7, -6.8, and -6.9 mm for 20, 40, and 60 pounds, respectively) and varus ligament balance (3.5°, 3.8°, and 3.8°) at extension and flexion were not significantly different among different joint distraction forces, although the joint center gap and varus ligament balance significantly increased stepwise at extension and flexion as the joint distraction force increased. The difference in joint center gap and varus ligament balance at extension and flexion were consistent even among the different joint distraction forces. This novel index would be useful for the determination of femoral component rotation during the modified gap-balancing technique. Copyright © 2017 Elsevier Inc. All rights reserved.

Trunk and hip biomechanics influence anterior cruciate loading mechanisms in physically active participants.

PubMed

Frank, Barnett; Bell, David R; Norcross, Marc F; Blackburn, J Troy; Goerger, Benjamin M; Padua, Darin A

2013-11-01

Excessive trunk motion and deficits in neuromuscular control (NMC) of the lumbopelvic hip complex are risk factors for anterior cruciate ligament (ACL) injury. However, the relationship between trunk motion, NMC of the lumbopelvic hip complex, and triplanar knee loads during a sidestep cutting task has not been examined. To determine if there is an association between multiplanar trunk motion, NMC of the lumbopelvic hip complex, and triplanar knee loads with ACL injury during a sidestep cutting task. Descriptive laboratory study. The hip and knee biomechanics and trunk motion of 30 participants (15 male, 15 female) were analyzed during a sidestep cutting task using an optoelectric camera system interfaced to a force plate. Trunk and lower extremity biomechanics were calculated from the kinematic and ground-reaction force data during the first 50% of the stance time during the cutting task. Pearson product moment correlation coefficients were calculated between trunk and lower extremity biomechanics. Multiple linear regression analyses were carried out to determine the amount of variance in triplanar knee loading explained by trunk motion and hip moments. A greater internal knee varus moment (mean, 0.11 ± 0.12 N·m/kg*m) was associated with less transverse-plane trunk rotation away from the stance limb (mean, 20.25° ± 4.42°; r = -0.46, P = .011) and a greater internal hip adduction moment (mean, 0.33 ± 0.25 N·m/kg*m; r = 0.83, P < .05). A greater internal knee external rotation moment (mean, 0.11 ± 0.08 N·m/kg*m) was associated with a greater forward trunk flexion (mean, 7.62° ± 5.28°; r = 0.42, P = .020) and a greater hip internal rotation moment (mean, 0.15 ± 0.16 N·m/kg*m; r = 0.59, P = .001). Trunk rotation and hip adduction moment explained 81% (P < .05) of the variance in knee varus moment. Trunk flexion and hip internal rotation moment explained 48% (P < .05) of the variance in knee external rotation moment. Limited trunk rotation displacement toward the new direction of travel and hip adduction moment are associated with an increased internal knee varus moment, while a combined increase in trunk flexion displacement and hip internal rotation moment is associated with a higher internal knee external rotation moment. Prevention interventions for ACL injury should encourage trunk rotation toward the new direction of travel and limit excessive trunk flexion while adjusting frontal- and transverse-plane hip NMC.

Effectiveness of prolonged use of continuous passive motion (CPM) as an adjunct to physiotherapy following total knee arthroplasty: design of a randomised controlled trial [ISRCTN85759656].

PubMed

Lenssen, Anton F; Crijns, Yvonne H F; Waltjé, Eddie M H; Roox, George M; van Steyn, Mike J A; Geesink, Ruud J T; van den Brandt, Piet A; de Bie, Rob A

2006-02-23

Adequate and intensive rehabilitation is an important requirement for successful Total Knee Arthroplasty. The primary focus of early rehabilitation is ambulation of patients and regaining range of motion in the knee. Although research suggests that Continuous Passive Motion should be implemented in the first rehabilitation phase following surgery, there is substantial debate about the duration of each session and the total period of CPM application and. A Cochrane review on this topic concluded that short-term use of CPM leads to greater short-term range of motion. It also suggested, however, that future research should concentrate on the treatment period during which CPM should be administered. In a randomised controlled trial we intend to investigate the efficacy of prolonged use of a continuous passive motion (CPM) device in the home situation as an adjunct to standardised physical therapy. The experimental treatment is compared to standardised physical therapy, in patients with osteoarthritis of the knee undergoing Total Knee Arthroplasty (TKA). Efficacy will be assessed in terms of faster improvements in range of motion and functional recovery. Seventy patients with knee osteoarthritis undergoing TKA and experiencing early postoperative flexion impairment (less than 80 degrees of knee flexion at the time of discharge) will be randomised over two treatment groups, a usual care group and an experimental group. The experimental group will receive CPM + physiotherapy for 17 consecutive days after surgery, whereas the usual care group will receive the same treatment during the in-hospital phase (i.e. about four days), followed by physical therapy alone (usual care) in the first two weeks after hospital discharge. From 18 days to three months after discharge, both groups will receive standardised PT. The primary focus of rehabilitation will be functional recovery (e.g. ambulation) and regaining range of motion (ROM) in the knee. Because restricted knee ROM affects functional activities, knee ROM and knee function are regarded as the primary indicators of successful TKA. Potential effects of the intervention under study include rapid return of knee flexion accompanied by earlier return to functional activities of daily life. If patients benefit significantly from prolonged CPM use, this treatment should be added to the standard PT treatment at home. We expect the additional home CPM programme to be more effective than the usual physiotherapy programme, resulting in a difference in ROM of at least 5 degrees , 17 days after surgery. This clinically important difference, with a possible flexion ROM of about 100 degrees , is expected to lead to better functioning in activities of daily life, like walking, and earlier ability to cycle. These advantages should result in earlier and increasing independence.

Effectiveness of prolonged use of continuous passive motion (CPM) as an adjunct to physiotherapy following total knee arthroplasty: Design of a randomised controlled trial [ISRCTN85759656

PubMed Central

Lenssen, Anton F; Crijns, Yvonne HF; Waltjé, Eddie MH; Roox, George M; van Steyn, Mike JA; Geesink, Ruud JT; van den Brandt, Piet A; de Bie, Rob A

2006-01-01

Background Adequate and intensive rehabilitation is an important requirement for successful Total Knee Arthroplasty. The primary focus of early rehabilitation is ambulation of patients and regaining range of motion in the knee. Although research suggests that Continuous Passive Motion should be implemented in the first rehabilitation phase following surgery, there is substantial debate about the duration of each session and the total period of CPM application and. A Cochrane review on this topic concluded that short-term use of CPM leads to greater short-term range of motion. It also suggested, however, that future research should concentrate on the treatment period during which CPM should be administered. Methods In a randomised controlled trial we intend to investigate the efficacy of prolonged use of a continuous passive motion (CPM) device in the home situation as an adjunct to standardised physical therapy. The experimental treatment is compared to standardised physical therapy, in patients with osteoarthritis of the knee undergoing Total Knee Arthroplasty (TKA). Efficacy will be assessed in terms of faster improvements in range of motion and functional recovery. Seventy patients with knee osteoarthritis undergoing TKA and experiencing early postoperative flexion impairment (less than 80° of knee flexion at the time of discharge) will be randomised over two treatment groups, a usual care group and an experimental group The experimental group will receive CPM + physiotherapy for 17 consecutive days after surgery, whereas the usual care group will receive the same treatment during the in-hospital phase (i.e. about four days), followed by physical therapy alone (usual care) in the first two weeks after hospital discharge. From 18 days to three months after discharge, both groups will receive standardised PT. The primary focus of rehabilitation will be functional recovery (e.g. ambulation) and regaining range of motion (ROM) in the knee. Discussion Because restricted knee ROM affects functional activities, knee ROM and knee function are regarded as the primary indicators of successful TKA. Potential effects of the intervention under study include rapid return of knee flexion accompanied by earlier return to functional activities of daily life. If patients benefit significantly from prolonged CPM use, this treatment should be added to the standard PT treatment at home. We expect the additional home CPM programme to be more effective than the usual physiotherapy programme, resulting in a difference in ROM of at least 5°, 17 days after surgery. This clinically important difference, with a possible flexion ROM of about 100°, is expected to lead to better functioning in activities of daily life, like walking, and earlier ability to cycle. These advantages should result in earlier and increasing independence. PMID:16504087

Variability of ischiofemoral space dimensions with changes in hip flexion: an MRI study.

PubMed

Johnson, Adam C; Hollman, John H; Howe, Benjamin M; Finnoff, Jonathan T

2017-01-01

The primary aim of this study was to determine if ischiofemoral space (IFS) dimensions vary with changes in hip flexion as a result of placing a bolster behind the knees during magnetic resonance imaging (MRI). A secondary aim was to determine if IFS dimensions vary between supine and prone hip neutral positions. The study employed a prospective design. Sports medicine center within a tertiary care institution. Five male and five female adult subjects (age mean = 29.2, range = 23-35; body mass index [BMI] mean = 23.5, range = 19.5-26.6) were recruited to participate in the study. An axial, T1-weighted MRI sequence of the pelvis was obtained of each subject in a supine position with their hips in neutral and flexed positions, and in a prone position with their hips in neutral position. Supine hip flexion was induced by placing a standard, 9-cm-diameter MRI knee bolster under the subject's knees. The order of image acquisition (supine hip neutral, supine hip flexed, prone hip neutral) was randomized. The IFS dimensions were then measured on a separate workstation. The investigator performing the IFS measurements was blinded to the subject position for each image. The main outcome measurements were the IFS dimensions acquired with MRI. The mean IFS dimensions in the prone position were 28.25 mm (SD 5.91 mm, standard error mean 1.32 mm). In the supine hip neutral position, the IFS dimensions were 25.1 (SD 5.6) mm. The mean difference between the two positions of 3.15 (3.6) mm was statistically significant (95 % CI of the difference = 1.4 to 4.8 mm, t 19  = 3.911, p = .001). The mean IFS dimensions in the hip flexed position were 36.9 (SD 5.7) mm. The mean difference between the two supine positions of 11.8 (4.1) mm was statistically significant (95 % CI of the difference = 9.9 to 13.7 mm, t 19  = 12.716, p < .001). Our findings demonstrate that the IFS measurements obtained with MRI are dependent upon patient positioning with respect to hip flexion and supine versus prone positions. This finding has implications when evaluating for ischiofemoral impingement, an entity resulting in hip and/or buttock pain secondary to impingement of the quadratus femoris muscle within a pathologically narrowed IFS. One will need to account for patient hip flexion and supine versus prone positioning when evaluating individuals with suspected ischiofemoral impingement.

Kinematics and muscle activity of the head, lumbar and knee joints during 180° turning and sitting down task in older adults.

PubMed

Kuo, Fang-Chuan; Hong, Chang-Zern; Liau, Ben-Yi

2014-01-01

The "180° turning and sitting down task" is a very conscious movement that requires focusing on turning at the exact moment, and very few studies address on this topic in older adults. The purpose of the study was to compare kinematics and electromyography of the head, lumbar and knee joints during 180°turning in older and young adults. Twenty older adults and 20 younger adults were assessed. A 16-channel telemetry electromyography system with electrogoniometers and an inclinometer were used to record the head, lumbar and knee joint kinematic and electromyography data during the 180° turning. This movement had been further divided into 4 phases (braking, mid-stance, swing, and terminal loading) for analysis. There were significant differences in the joint displacement and muscular activity among the different phases. Comparison between groups showed that the older adults group had less lateral lumbar flexion, less knee flexion and lower velocity of the head and knee flexion compared to young adults during turning. The electromyography data of the left biceps femoris, left gastrocnemius and left erector spinae muscles in the older adults group showed significantly higher levels than in the young adults. Older adults need to adjust velocities of moving joints and increase the extensor synergy muscles of the back and the stance leg to provide posture stability. Kinematics and neuromuscular modulations of the head, lumbar and knee are required according to the various phases of the turn movements and change with aging. © 2013.

Strength deficit of knee flexors is dependent on hip position in adults with chronic hemiparesis.

PubMed

Michaelsen, Stella M; Ovando, Angélica C; Bortolotti, Adriano; Bandini, Bruno

2013-01-01

The extent to which muscle length affects force production in paretic lower limb muscles after stroke in comparison to controls has not been established. To investigate knee flexor strength deficits dependent on hip joint position in adults with hemiparesis and compare with healthy controls. a cross-sectional study with ten subjects with chronic (63±40 months) hemiparesis with mild to moderate lower limb paresis (Fugl-Meyer score 26±3) and 10 neurologically healthy controls. Isometric knee flexion strength with the hip positioned at 90° and 0° of flexion was assessed randomly on the paretic and non-paretic side of hemiparetic subjects and healthy controls. Subjects were asked to perform a maximal isometric contraction sustained for four seconds and measured by a dynamometer. The ratio of knee flexor strength between these two hip positions was calculated: Hip 0°/Hip 90°. Also, locomotor capacity was evaluated by the timed up and go test and by walking velocity over 10 meters. In subjects with hemiparesis, absolute knee flexion torque decreased (p<0.001) with the hip in extension (at 0°). The ratio of knee flexor torque Hip 0°/Hip 90° on the paretic side in hemiparetics was lower than in controls (p=0.02). Weakness dependent on joint position is more significant in the paretic lower limb of adults with hemiparesis when compared to controls. More attention should be given to lower limb muscle strengthening exercises in individuals with stroke, with emphasis on the strengthening exercises in positions in which the muscle is shortened.

Position of the quadriceps actuator influences knee loads during simulated squat testing.

PubMed

Hast, Michael W; Piazza, Stephen J

2018-05-17

The "Oxford Rig" cadaveric simulator permits researchers and clinicians to study knee mechanics during a simulated squatting motion. The motion of the lower limb in the Oxford Rig is typically controlled by a single actuator that applies tension to the quadriceps tendon. The location of the quadriceps actuator, however, has differed across published descriptions of the Oxford Rig. Actuators have been placed on the femur and pelvis, and on "grounded" locations external to the specimen, but the consequences of this placement for knee kinematics and kinetics are unknown. The purpose of this study was to examine these effects using a validated computational musculoskeletal model. When the actuator was placed on the femur or pelvis, forces realistically increased with knee flexion, with quadriceps and patellofemoral contact forces exceeding 2000 N and 3000 N, respectively, at 100° flexion. When the actuator was grounded, however, forces were substantially reduced and did not monotonically increase with flexion. Articular joint contact forces were not strongly influenced by changing the location of the actuator from the femur to the pelvis, with small RMS differences in quadriceps forces (48.2 N), patellofemoral forces (83.6 N), and tibiofemoral forces (58.9 N) between these conditions. The location of the actuator did not substantially affect knee kinematics. The results of this study suggest that the quadriceps actuator of the Oxford Rig should be attached to either the femur or the pelvis when the goal is to make realistic estimates of quadriceps forces and articular contact forces within the knee joint. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Validity of a New Low-Dose Stereoradiography System to Perform 2D and 3D Knee Prosthetic Alignment Measurements.

PubMed

Meijer, Marrigje F; Velleman, Ton; Boerboom, Alexander L; Bulstra, Sjoerd K; Otten, Egbert; Stevens, Martin; Reininga, Inge H F

2016-01-01

The EOS stereoradiography system has shown to provide reliable varus/valgus (VV) measurements of the lower limb in 2D (VV2D) and 3D (VV3D) after total knee arthroplasty (TKA). Validity of these measurements has not been investigated yet, therefore the purpose of this study was to determine validity of EOS VV2D and VV3D. EOS images were made of a lower limb phantom containing a knee prosthesis, while varying VV angle from 15° varus to 15° valgus and flexion angle from 0° to 20°, and changing rotation from 20° internal to 20° external rotation. Differences between the actual VV position of the lower limb phantom and its position as measured on EOS 2D and 3D images were investigated. Rotation, flexion or VV angle alone had no major impact on VV2D or VV3D. Combination of VV angle and rotation with full extension did not show major differences in VV2D measurements either. Combination of flexion and rotation with a neutral VV angle showed variation of up to 7.4° for VV2D; maximum variation for VV3D was only 1.5°. A combination of the three variables showed an even greater distortion of VV2D, while VV3D stayed relatively constant. Maximum measurement difference between preset VV angle and VV2D was 9.8°, while the difference with VV3D was only 1.9°. The largest differences between the preset VV angle and VV2D were found when installing the leg in extreme angles, for example 15° valgus, 20° flexion and 20° internal rotation. After TKA, EOS VV3D were more valid than VV2D, indicating that 3D measurements compensate for malpositioning during acquisition. Caution is warranted when measuring VV angle on a conventional radiograph of a knee with a flexion contracture, varus or valgus angle and/or rotation of the knee joint during acquisition.

Rater agreement reliability of the dial test in the ACL-deficient knee.

PubMed

Slichter, Malou E; Wolterbeek, Nienke; Auw Yang, K Gie; Zijl, Jacco A C; Piscaer, Tom M

2018-06-14

Posterolateral rotatory instability (PLRI) of the knee can easily be missed, because attention is paid to injury of the cruciate ligaments. If left untreated this clinical instability may persist after reconstruction of the cruciate ligaments and may put the graft at risk of failure. Even though the dial test is widely used to diagnose PLRI, no validity and reliability studies of the manual dial test are yet performed in patients. This study focuses on the reliability of the manual dial test by determining the rater agreement. Two independent examiners performed the dial test in knees of 52 patients after knee distorsion with a suspicion on ACL rupture. The dial test was performed in prone position in 30°, 60° and 90° of flexion of the knees. ≥10° side-to-side difference was considered a positive dial test. For quantification of the amount of rotation in degrees, a measuring device was used with a standardized 6 Nm force, using a digital torque adapter on a booth. The intra-rater, inter-rater and rater-device agreement were determined by calculating kappa (κ) for the dial test. A positive dial test was found in 21.2% and 18.0% of the patients as assessed by a blinded examiner and orthopaedic surgeon respectively. Fair inter-rater agreement was found in 30° of flexion, κ F  = 0.29 (95% CI: 0.01 to 0.56), p = 0.044 and 90° of flexion, κ F  = 0.38 (95% CI: 0.10 to 0.66), p = 0.007. Almost perfect rater-device agreement was found in 30° of flexion, κ C  = 0.84 (95% CI: 0.52 to 1.15), p < 0.001. Moderate rater-device agreement was found in 30° and 90° combined, κ C  = 0.50 (95% CI: 0.13 to 0.86), p = 0.008. No significant intra-rater agreement was found. Rater agreement reliability of the manual dial test is questionable. It has a fair inter-rater agreement in 30° and 90° of flexion.

[Mini-subvastus approach for total knee replacement].

PubMed

Halder, Andreas; Beier, Alexander; Neumann, Wolfram

2009-03-01

Total knee replacement in minimally invasive technique without any trauma to the extensor apparatus and with soft-tissue-referenced bone resections. Only the subvastus approach preserves the integrity of the extensor apparatus and has therefore been modified to become a minimally invasive technique with a shorter skin incision and lateralization instead of eversion of the patella. Soft-tissue balancing is done through this direct anterior approach. Mild to moderate varus osteoarthritis of the knee up to 15 degrees of malalignment, mild and passively correctable valgus osteoarthritis of the knee up to 10 degrees of malalignment. Severe, contract varus osteoarthritis of the knee, severe and moderate, contract valgus osteoarthritis of the knee, severe obesity, exceptionally muscular patients, decreased skin perfusion. Central skin incision from the superior pole of the patella to the tibial tubercle. Exposure of the medial retinaculum and mobilization of the vastus medialis muscle subcutaneously. Incision of the medial retinaculum and blunt separation of the vastus medialis muscle from the intermuscular septum. Lateralization of the patella and flexion of the knee joint. Resection of the tibia perpendicular to the diaphysis. Adjustment of the anteroposterior (AP) resection block at the level of the anterior femoral cortex and of rotation by applying equal tension to the collateral ligaments. Balancing of soft-tissue tension in flexion gap by release, if necessary. After AP resection fixation of distal resection block in planned valgus angle. Balancing of soft-tissue tension in extension gap by release, if necessary. After distal femur resection facet resection, adaptation of posterior femoral condyles, and implantation of prosthesis. Check on stability and range of motion. Wound closure. Full weight bearing from the 1st postoperative day, CPM (continuous passive motion) with up to 90 degrees flexion with peridural anesthesia as tolerated, stair climbing starting on the 7th postoperative day. 100 patients were randomized to total knee replacement via a parapatellar or subvastus approach. Radiologically, there were no differences in operative precision or leg alignment. Patients treated minimally invasively suffered less pain and achieved a higher flexion of 110 degrees versus 95 degrees 6 weeks postoperatively. However, there were two cases of delayed wound healing in this group. The surgical technique is demanding and the operating time is longer. Long-term results are still missing.

WHO Class of Obesity Influences Functional Recovery Post-TKA.

PubMed

Maniar, Rajesh N; Maniar, Parul R; Singhi, Tushar; Gangaraju, Bharat Kumar

2018-03-01

No study in the literature has compared early functional recovery following total knee arthroplasty (TKA) in the obese with the nonobese using World Health Organization (WHO) classes of obesity. Our aim was to compare functional scores and flexion post-TKA in each class of obesity as per WHO classification against a matched control group of nonobese patients. Records of 885 consecutive primary TKA patients (919 knees) operated by a single surgeon were reviewed. The first 35 knees in each class I, class II and class III obesity group during the study period were then matched with a similar number of knees in nonobese TKA patients during the same period. Functional scores recorded pre- and postoperatively at 3 months and 1 year were Western Ontario and McMaster Osteoarthritis Index (WOMAC), Short-Form Health Survey (SF-12) score, and Knee Society Score (KSS). There was no difference in any parameter between the class I obese and matched nonobese at any assessment point. In the class II obese, as compared to the nonobese, there was no difference in any parameter preoperatively and 3 months postoperatively. However, 1 year postoperatively, the SF-12 physical subscore was lower in the class II obese than the nonobese (44.7 vs. 48.6, p = 0.047) and the WOMAC score was significantly higher (15.8 vs. 9.7, p = 0.04). In the class III obese, the WOMAC score was significantly higher than the nonobese (58.1 vs. 44.3, p < 0.001 preoperatively; 15.7 vs. 8.1, p = 0.005 at 1 year) and KSS was significantly lower (83.5 vs. 96.5, p = 0.049 preoperatively; 172 vs. 185; p = 0.003 at 1 year). Knee flexion was significantly lower in the class III obese than the nonobese (95 vs. 113; p < 0.001 preoperatively; 120 vs. 127; p = 0.002 at 1 year). The class I obese can expect good early and late functional recovery as the nonobese. The class II obese can expect comparable early functional recovery as the nonobese but their late function may be lesser. The class III obese would have poorer functional scores and lesser knee flexion postoperatively compared to the nonobese. However, compared to their own preoperative status, there is definite improvement in function and knee flexion.

Predictors of proximal tibia anterior shear force during a vertical stop-jump.

PubMed

Sell, Timothy C; Ferris, Cheryl M; Abt, John P; Tsai, Yung-Shen; Myers, Joseph B; Fu, Freddie H; Lephart, Scott M

2007-12-01

Anterior cruciate ligament (ACL) continues to be a significant medical issue for athletes participating in sports and recreational activities. Biomechanical analyses have determined that anterior shear force is the most direct loading mechanism of the ACL and a probable component of noncontact ACL injury. The purpose of this study was to examine the biomechanical predictors of proximal tibia anterior shear force during a stop-jump task. A biomechanical and electromyographic (EMG) analysis of the knee was conducted while subjects performed a vertical stop-jump task. The task was chosen to simulate an athletic maneuver that included a landing with a sharp deceleration and a change in direction. The final regression model indicated that posterior ground reaction force, external knee flexion moment, knee flexion angle, integrated EMG activity of the vastus lateralis, and sex (female) would significantly predict proximal tibia anterior shear force (p < 0.0001, R2 = 0.8609). Knee flexion moment had the greatest influence on proximal tibia anterior shear force. The mathematical relationships elucidated in the current study support previous clinical and basic science research examining noncontact ACL injuries. This data provides important evidence for clinicians who are examining the risk factors for these injuries and developing/validating training programs to reduce the incidence of injury. Copyright 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Isokinetic strength and endurance during 30-day 6 degrees head-down bed rest with isotonic and isokinetic exercise training

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Bernauer, E. M.; Ertl, A. C.; Bulbulian, R.; Bond, M.

1994-01-01

The purpose of our study was to determine if an intensive, intermittent, isokinetic, lower extremity exercise training program would attenuate or eliminate the decrease of muscular strength and endurance during prolonged bed rest (BR). The 19 male subjects (36 +/- 1 yr, 178 +/- 2 cm, 76.5 +/- 1.7 kg) were allocated into a no exercise (NOE) training group (N = 5), an isotonic (lower extremity cycle ergometer) exercise (ITE) training group (N = 7), and an isokinetic (isokinetic knee flexion-extension) exercise (IKE) training group (N = 7). Peak knee (flexion and extension) and shoulder (abduction-adduction) functions were measured weekly in all groups with one 5-repetition set. After BR, average knee extension total work decreased by 16% with NOE, increased by 27% with IKE, and was unchanged with ITE. Average knee flexion total work and peak torque (strength) responses were unchanged in all groups. Force production increased by 20% with IKE and was unchanged with NOE and ITE. Shoulder total work was unchanged in all groups, while gross average peak torque increased by 27% with ITE and by 22% with IKE, and was unchanged with NOE. Thus, while ITE training can maintain some isokinetic functions during BR, maximal intermittent IKE training can increase other functions above pre-BR control levels.

Isokinetic Strength and Endurance During 30-day 6 deg Head-Down Bed Rest with Isotonic and Isokinetic Exercise Training

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Bernauer, E. M.; Ertl, A. C.; Bond, M.; Bulbulian, R.

1994-01-01

The purpose of our study was to determine if an intensive, intermittent, isokinetic, lower extremity exercise training program would attenuate or eliminate the decrease of muscular strength and endurance during prolonged bed rest (BR). The 19 male subjects (36 +/- 1 yr, 178 +/- 2 cm, 76.5 +/- 1.7 kg) were allocated into a no exercise (NOE) training group (N = 5), an isotonic (lower extremity cycle orgometer) exercise (ITE) training group (N = 7), and an isokinetic (isokinetic knee flexion-extension) exercise (IKE) training group (N = 7). Peak knee (flexion and extension) and shoulder (abduction-adduction) functions were measured weekly in all groups with one 5-repetition set. After BR, average knee extension total work decreased by 16% with NOE, increased by 27% with IKE, and was unchanged with ITE. Average knee flexion total work and peak torque (strength) responses were unchanged in all groups. Force production increased by 20% with IKE and was unchanged with NOE and ITE. Shoulder total work was unchanged in all groups, while gross average peak torque increased by 27% with ITE and by 22% with IKE, and was unchanged with NOE. Thus, while ITE training can maintain some isokinetic functions during BR, maximal intermittent IKE training can increase other functions above pre-BR control levels.

The effect of trunk flexion on lower-limb kinetics of able-bodied gait.

PubMed

Kluger, David; Major, Matthew J; Fatone, Stefania; Gard, Steven A

2014-02-01

Able-bodied individuals spontaneously adopt crouch gait when walking with induced anterior trunk flexion, but the effect of this adaptation on lower-limb kinetics is unknown. Sustained forward trunk displacement during walking can greatly alter body center-of-mass location and necessitate a motor control response to maintain upright balance. Understanding this response may provide insight into the biomechanical demands on the lower-limb joints of spinal pathology that alter trunk alignment (e.g., flatback). The purpose of this study was to determine the effect of sustained trunk flexion on lower-limb kinetics in able-bodied gait, facilitating understanding of the effects of spinal pathologies. Subjects walked with three postures: 0° (normal upright), 25±7°, and 50±7° trunk flexion. With increased trunk flexion, decreased peak ankle plantar flexor moments were observed with increased energy absorption during stance. Sustained knee flexion during mid- and terminal stance decreased knee flexor moments, but energy absorption/generation remained unchanged across postures. Increased trunk flexion placed significant demand on the hip extensors, thus increasing peak hip extensor moments and energy generation. The direct relationship between trunk flexion and energy absorption/generation at the ankle and hip, respectively, suggest increased muscular demand during gait. These findings on able-bodied subjects might shed light on muscular demands associated with individuals having pathology-induced positive sagittal spine balance. Copyright © 2013 Elsevier B.V. All rights reserved.

Lower extremity kinematics and kinetics of Division III collegiate baseball and softball players while performing a modified pro-agility task.

PubMed

Wallace, B J; Kernozek, T W; Bothwell, E C

2007-12-01

Females experience at least twice as many non-contact anterior cruciate ligament (ACL) injuries as males. The aim of this study was to investigate if males and females exhibited different characteristics while performing a modified pro-agility test. Collegiate Division III male baseball (n=14) and female softball (n=13) players performed 4 trials of a modified pro-agility task, which consisted of running toward a force platform target for 5 steps, planting their right foot, and propelling themselves off of the target with their left foot. Kinematic and kinetic parameters were compared using a multivariate analysis of variance between gender with the level of significance set at P<0.05. Males and females exhibited similar knee valgus angles. Females had a greater maximum knee extension angle (10.14 degrees vs 17.43 degrees ), and greater knee range of motion (46.12 degrees vs 40.12 degrees ). Both groups reached maximum knee flexion at 52% of stance. Females had significantly more maximum hip flexion than males (28.86 degrees vs 22.75 degrees ). Females had significantly smaller minimum internal knee varus moments than their male counterparts (1.12 Nm/kg vs 1.55 Nm/kg). Vertical ground reaction forces as a percentage of bodyweight, and stance time, were not statistically different. The female group displayed an external knee rotation angle (2.49 degrees ) during the beginning of their stance, which was significantly different than the internal rotation angle (4.11 degrees ) in the male group. Early in stance knee rotation angle was highly correlated with the lack of internal knee varus moment (males R(2)=0.75, females R(2)=0.88). Females displayed knee moments and kinematics that may place them at greater risk for ACL injury during a stop-cut task. Females should be coached to perform stop cuts with more knee flexion and a more neutral knee rotation angle upon foot contact in an effort to reduce moments that may place the ACL at risk.

Anatomic double-bundle anterior cruciate ligament reconstruction restores patellofemoral contact areas and pressures more closely than nonanatomic single-bundle reconstruction.

PubMed

Tajima, Goro; Iriuchishima, Takanori; Ingham, Sheila J M; Shen, Wei; van Houten, Albert H; Aerts, Maarten M; Shimamura, Tadashi; Smolinski, Patrick; Fu, Freddie H

2010-10-01

To investigate the effects of anterior cruciate ligament (ACL) deficiency and nonanatomic single-bundle (SB) and anatomic double-bundle (DB) ACL reconstruction on the contact characteristics of the patellofemoral (PF) joint. By use of a materials testing system, 7 fresh-frozen human cadaveric knees were tested. The following states were tested: ACL-intact knee, nonanatomic SB ACL reconstruction, anatomic DB ACL reconstruction, and ACL-deficient knee. Hamstring autografts were used. PF contact pressures and areas were measured with pressure-sensitive film at 30°, 60°, and 90° of knee flexion with a constant 100-N load on the quadriceps tendon. The total contact area of ACL-deficient and nonanatomic SB ACL-reconstructed knees (123.8 ± 63.9 and 149.6 ± 79.3 mm(2), respectively) significantly decreased when compared with those of the intact knee (206.1 ± 83.6 mm(2)) at 30° of knee flexion. The lateral-facet peak pressure of ACL-deficient and nonanatomic SB ACL-reconstructed knees (1.12 ± 0.52 and 1.22 ± 0.54 MPa, respectively) significantly decreased when compared with those of the intact knee (0.68 ± 0.38 MPa) at 90° of knee flexion. Anatomic DB ACL reconstruction restored the contact pressures and areas to values similar to those of the intact knee (no significant difference). ACL deficiency resulted in a significant decrease in the total and medial PF contact areas and in an increase in the lateral PF contact pressure. Anatomic DB ACL reconstruction more closely restored normal PF contact area and pressure than did nonanatomic SB ACL reconstruction. Our findings suggest that the changes in the PF contact area and pressures in ACL deficiency and after nonanatomic SB ACL reconstruction may be one of the causes of PF osteoarthritis or other related PF problems found at long-term follow-up. Anatomic DB ACL reconstruction may reduce the incidence of PF problems by closely restoring the contact area and pressure. Copyright © 2010 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

The role of knee joint moments and knee impairments on self-reported knee pain during gait in patients with knee osteoarthritis.

PubMed

O'Connell, Megan; Farrokhi, Shawn; Fitzgerald, G Kelley

2016-01-01

The association between high mechanical knee joint loading during gait with onset and progression of knee osteoarthritis has been extensively studied. However, less attention has been given to risk factors related to increased pain during gait. The purpose of this study was to evaluate knee joint moments and clinical characteristics that may be associated with gait-related knee pain in patients with knee osteoarthritis. Sixty-seven participants with knee osteoarthritis were stratified into three groups of no pain (n=18), mild pain (n=27), or moderate/severe pain (n=22) based on their self-reported symptoms during gait. All participants underwent three-dimensional gait analysis. Quadriceps strength, knee extension range of motion, radiographic knee alignment and self-reported measures of global pain and function were also quantified. The moderate/severe pain group demonstrated worse global pain (P<0.01) and physical function scores (P<0.01) compared to the no pain and the mild pain groups. The moderate/severe pain group also walked with greater knee flexion moments during the midstance phase of gait compared to the no pain group (P=0.02). Additionally, the moderate/severe pain group demonstrated greater varus knee malalignment (P=0.009), which was associated with higher weight acceptance peak knee adduction moments (P=0.003) and worse global pain (P=0.003) and physical function scores (P=0.006). Greater knee flexion moment is present during the midstance phase of gait in patients with knee osteoarthritis and moderate/severe pain during gait. Additionally, greater varus malalignment may be a sign of increased global knee joint dysfunction that can influence many activities of daily living beyond gait. Copyright © 2015 Elsevier Ltd. All rights reserved.

Designs and performance of three new microprocessor-controlled knee joints.

PubMed

Thiele, Julius; Schöllig, Christina; Bellmann, Malte; Kraft, Marc

2018-02-09

A crossover design study with a small group of subjects was used to evaluate the performance of three microprocessor-controlled exoprosthetic knee joints (MPKs): C-Leg 4, Plié 3 and Rheo Knee 3. Given that the mechanical designs and control algorithms of the joints determine the user outcome, the influence of these inherent differences on the functional characteristics was investigated in this study. The knee joints were evaluated during level-ground walking at different velocities in a motion analysis laboratory. Additionally, technical analyses using patents, technical documentations and X-ray computed tomography (CT) for each knee joint were performed. The technical analyses showed that only C-Leg 4 and Rheo Knee 3 allow microprocessor-controlled adaptation of the joint resistances for different gait velocities. Furthermore, Plié 3 is not able to provide stance extension damping. The biomechanical results showed that only if a knee joint adapts flexion and extension resistances by the microprocessor all known advantages of MPKs can become apparent. But not all users may benefit from the examined functions: e.g. a good accommodation to fast walking speeds or comfortable stance phase flexion. Hence, a detailed comparison of user demands and performance of the designated knee joint is mandatory to ensure a maximum in user outcome.

Lean muscle volume of the thigh has a stronger relationship with muscle power than muscle strength in women with knee osteoarthritis.

PubMed

Davison, Michael J; Maly, Monica R; Keir, Peter J; Hapuhennedige, Sandani M; Kron, Amie T; Adachi, Jonathan D; Beattie, Karen A

2017-01-01

Thigh lean muscle and intramuscular fat have been implicated in the impairment of physical function observed in people with knee osteoarthritis. We investigated the relationships of quadriceps and hamstrings intramuscular fat fraction and lean muscle volume with muscle power and strength, controlling for neuromuscular activation, and physical performance in women with knee OA. Women (n=20) 55years or older with symptomatic, radiographic knee osteoarthritis underwent a 3.0T magnetic resonance imaging scan of the thigh of their most symptomatic knee. Axial fat-separated images were analyzed using software to quantify intramuscular fat and lean muscle volumes of the quadriceps and hamstrings. To quantify strength and power of the knee extensors and flexors, participants performed maximum voluntary isometric contraction and isotonic knee extensions and flexions, respectively. Electromyography of the quadriceps and hamstrings was measured. Participants also completed five physical performance tests. Quadriceps and hamstrings lean muscle volumes were related to isotonic knee extensor (B=0.624; p=0.017) and flexor (B=1.518; p=0.032) power, but not knee extensor (B=0.001; p=0.615) or flexor (B=0.001; p=0.564) isometric strength. Intramuscular fat fractions were not related to isotonic knee extensor or flexor power, nor isometric strength. No relationships were found between intramuscular fat or lean muscle volume and physical performance. Muscle power may be more sensitive than strength to lean muscle mass in women with knee osteoarthritis. Thigh lean muscle mass, but neither intramuscular nor intermuscular fat, is related to knee extensor and flexor power in women with knee osteoarthritis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Knee joint kinematics and kinetics during the hop and cut after soft tissue artifact suppression: Time to reconsider ACL injury mechanisms?

PubMed

Smale, Kenneth B; Potvin, Brigitte M; Shourijeh, Mohammad S; Benoit, Daniel L

2017-09-06

The recent development of a soft tissue artifact (STA) suppression method allows us to re-evaluate the tibiofemoral kinematics currently linked to non-contact knee injuries. The purpose of this study was therefore to evaluate knee joint kinematics and kinetics in six degrees of freedom (DoF) during the loading phases of a jump lunge and side cut using this in silico method. Thirty-five healthy adults completed these movements and their surface marker trajectories were then scaled and processed with OpenSim's inverse kinematics (IK) and inverse dynamics tools. Knee flexion angle-dependent kinematic constraints defined based on previous bone pin (BP) marker trajectories were then applied to the OpenSim model during IK and these constrained results were then processed with the standard inverse dynamics tool. Significant differences for all hip, knee, and ankle DoF were observed after STA suppression for both the jump lunge and side cut. Using clinically relevant effect size estimates, we conclude that STA contamination had led to misclassifications in hip transverse plane angles, knee frontal and transverse plane angles, medial/lateral and distractive/compressive knee translations, and knee frontal plane moments between the NoBP and the BP IK solutions. Our results have substantial clinical implications since past research has used joint kinematics and kinetics contaminated by STA to identify risk factors for musculoskeletal injuries. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Surgical technique and clinical results of total knee arthroplasty in treating endstage gonarthrosis combined with valgus knee deformity].

PubMed

Wang, Xingshan; Weng, Xisheng; Lin, Jin; Jin, Jin; Qian, Wenwei

2012-05-01

To investigate the surgical technique and the clinical results of total knee arthroplasty (TKA) in treating end-stage gonarthrosis combined with valgus knee deformity. Between November 1998 and October 2010, 64 patients (72 knees) with end-stage gonarthrosis combined with valgus knee deformity underwent TKA by a medial parapatellar approach. Of the 64 patients, 18 were male and 46 were female with an average age of 62.5 years (range, 23-82 years), including 44 cases (49 knees) of osteoarthritis, 17 cases (20 knees) of rheumatoid arthritis, 2 cases (2 knees) of haemophilic arthritis, and 1 case (1 knee) of post-traumatic arthritis. Bilateral knees were involved in 8 cases, and single knee in 56 cases. The flexion and extension range of motion (ROM) of the knee joint was (82.2 +/- 28.7) degrees; the femur-tibia angle (FTA) was (18.0 +/- 5.8) degrees; according to Knee Society Score (KSS) criterion, the preoperative clinical score was 31.2 +/- 10.1 and functional score was 37.3 +/- 9.0. According to Krackow's classification, there were 65 knees of type I and 7 knees of type II. By medial parapatellar approach, conventional osteotomy and Ranawat soft tissue release were performed in all cases. Prosthesis of preserved posterior cruciate ligament were used in 7 cases (7 knees), posterior stabilize prosthesis in 54 cases (60 knees), constrained prosthesis in 4 cases (5 knees). Incisions healed by first intention in all cases. Peroneal nerve palsy occurred in 1 patient with haemophilic arthritis, severe valgus deformity (FTA was 41 degrees), and flexion contracture (20 degrees), which was cured after 1 year of conservative treatment. Revison surgery was performed in 1 case of deep infection at 2 years after surgery. All the patients were followed up 4.9 years on average (range, 1-13 years). At last follow-up, the FTA was (7.0 +/- 2.5) degrees, showing significant difference when compared with preoperative value (t = 15.502, P = 0.000). The KSS clinical score was 83.0 +/- 6.6 and functional score was 85.1 +/- 10.5, the flexion and extension ROM of the knee joint was (106.1 +/- 17.0) degrees, all showing significant differences when compared with preoperative values (P < 0.05). Five patients had 12-15 degrees valgus knee deformity, but the function of the affect knees were good. TKA is an effective way for the patients with end-stage gonarthrosis combined with valgus knee deformity by medial parapatellar approach combined with conventional osteotomy and Ranawat soft tissue release. The correction of deformity and improvement of joint function can be achieved significantly. The clinical result is satisfactory.

Influence of the posterior tibial slope on the flexion gap in total knee arthroplasty.

PubMed

Okazaki, Ken; Tashiro, Yasutaka; Mizu-uchi, Hideki; Hamai, Satoshi; Doi, Toshio; Iwamoto, Yukihide

2014-08-01

Adjusting the joint gap length to be equal in both extension and flexion is an important issue in total knee arthroplasty (TKA). It is generally acknowledged that posterior tibial slope affects the flexion gap; however, the extent to which changes in the tibial slope angle directly affect the flexion gap remains unclear. This study aimed to clarify the influence of tibial slope changes on the flexion gap in cruciate-retaining (CR) or posterior-stabilizing (PS) TKA. The flexion gap was measured using a tensor device with the femoral trial component in 20 cases each of CR- and PS-TKA. A wedge plate with a 5° inclination was placed on the tibial cut surface by switching its front-back direction to increase or decrease the tibial slope by 5°. The flexion gap after changing the tibial slope was compared to that of the neutral slope measured with a flat plate that had the same thickness as that of the wedge plate center. When the tibial slope decreased or increased by 5°, the flexion gap decreased or increased by 1.9 ± 0.6mm or 1.8 ± 0.4mm, respectively, with CR-TKA and 1.2 ± 0.4mm or 1.1 ± 0.3mm, respectively, with PS-TKA. The influence of changing the tibial slope by 5° on the flexion gap was approximately 2mm with CR-TKA and 1mm with PS-TKA. This information is useful when considering the effect of manipulating the tibial slope on the flexion gap when performing CR- or PS-TKA. Copyright © 2014 Elsevier B.V. All rights reserved.

Flexion and extension gaps created by the navigation-assisted gap technique show small acceptable mismatches and close mutual correlations.

PubMed

Lee, Dae-Hee; Shin, Young-Soo; Jeon, Jin-Ho; Suh, Dong-Won; Han, Seung-Beom

2014-08-01

The aim of this study was to investigate the mechanism underlying the development of gap differences in total knee arthroplasty using the navigation-assisted gap technique and to assess whether these gap differences have statistical significance. Ninety-two patients (105 knees) implanted with cruciate-retaining prostheses using the navigation-assisted gap balancing technique were prospectively analysed. Medial extension and flexion gaps and lateral extension and flexion gaps were measured at full extension and at 90° of flexion. Repeated measures analysis of variance was used to compare the mean values of these four gaps. The correlation coefficient between each pair of gaps was assessed using Pearson's correlation analysis. Mean intra-operative medial and lateral extension gaps were 20.6 ± 2.1 and 21.7 ± 2.2 mm, respectively, and mean intra-operative medial and lateral flexion gaps were 21.6 ± 2.7 and 22.1 ± 2.5 mm, respectively. The pairs of gaps differed significantly (P < 0.05 each), except for the difference between the medial flexion and lateral extension gaps (n.s.). All four gaps were significantly correlated with each other, with the highest correlation between the medial and lateral flexion gaps (r = 0.890, P < 0.001) and the lowest between the medial flexion and lateral extension gaps (r = 0.701, P < 0.001). Medial and lateral flexion and extension gaps created using the navigation-assisted gap technique differed significantly, although the differences between them were <2 mm, and the gaps were closely correlated. These narrow ranges of statistically acceptable gap differences and the strong correlations between gaps should be considered by surgeons, as should the risks of soft tissue over-release or unintentional increases in extension or flexion gap after preparation of the other gap.

Development and validation of a weight-bearing finite element model for total knee replacement.

PubMed

Woiczinski, M; Steinbrück, A; Weber, P; Müller, P E; Jansson, V; Schröder, Ch

2016-01-01

Total knee arthroplasty (TKA) is a successful procedure for osteoarthritis. However, some patients (19%) do have pain after surgery. A finite element model was developed based on boundary conditions of a knee rig. A 3D-model of an anatomical full leg was generated from magnetic resonance image data and a total knee prosthesis was implanted without patella resurfacing. In the finite element model, a restarting procedure was programmed in order to hold the ground reaction force constant with an adapted quadriceps muscle force during a squat from 20° to 105° of flexion. Knee rig experimental data were used to validate the numerical model in the patellofemoral and femorotibial joint. Furthermore, sensitivity analyses of Young's modulus of the patella cartilage, posterior cruciate ligament (PCL) stiffness, and patella tendon origin were performed. Pearson's correlations for retropatellar contact area, pressure, patella flexion, and femorotibial ap-movement were near to 1. Lowest root mean square error for retropatellar pressure, patella flexion, and femorotibial ap-movement were found for the baseline model setup with Young's modulus of 5 MPa for patella cartilage, a downscaled PCL stiffness of 25% compared to the literature given value and an anatomical origin of the patella tendon. The results of the conducted finite element model are comparable with the experimental results. Therefore, the finite element model developed in this study can be used for further clinical investigations and will help to better understand the clinical aspects after TKA with an unresurfaced patella.

Neuromuscular performance of maximal voluntary explosive concentric contractions is influenced by angular acceleration.

PubMed

Hahn, D; Bakenecker, P; Zinke, F

2017-12-01

Torque production during maximal voluntary explosive contractions is considered to be a functionally more relevant neuromuscular measure than steady-state torque, but little is known about accelerated concentric contractions. This study investigated torque, muscle activity, and fascicle behavior during isometric and fast concentric contractions of quadriceps femoris. Ten participants performed maximal voluntary explosive isometric, isovelocity, and additional concentric knee extensions at angular accelerations ranging from 700 to 4000° s -2 that resulted in an angular velocity of 300° s -1 at 40° knee flexion. Concentric torque at 40° knee flexion was corrected for inertia, and the corresponding isometric torque was matched to the time when the target knee angle of 40° was reached during concentric contractions. Electromyography of quadriceps femoris and hamstrings and ultrasound of vastus lateralis were measured to determine muscle activity, fascicle length, and fascicle velocity (FV). The faster the acceleration, the more torque was produced during concentric contractions at 40° knee flexion, which was accompanied by a reduction in FV. In comparison with isometric conditions, concentric quadriceps muscle activity was increased and torque during accelerations ≥3000° s -2 equaled the time-matched isometric torque. Our results provide novel evidence that acceleration influences torque production during maximal voluntary explosive concentric contractions. This is suggested to be due to series elasticity and reduced force depression. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Knee flexion contracture treated with botulinum toxin type A in patients with haemophilia (PWH).

PubMed

Daffunchio, C; Caviglia, H; Nassif, J; Morettil, N; Galatro, G

2016-01-01

Knee flexion contracture (KFC) remains a common complication of haemoarthrosis in children and young adults with haemophilia. If the KFC is not treated properly it produces disability, postural and gait abnormalities. Evaluate the effectiveness of conservative treatment of KFC with Botulinum toxin type A (BTX-A) in PWH. Seventeen patients were treated, with 21 affected knees. Mean age was 26 years. The mean follow up was 12 months. We evaluated flexion and KFC pretreatment BTX-A and up to 12 months posttreatment. BTX-A application was in hamstring and calf muscles. To evaluate the function, a questionnaire about different activities was made, and it was checked 3, 6 and 12 months after BTX-A. According to the degree of KFC, knees were divided into 3 groups: Group 1: -10° to -30° (n = 10), Group 2: -31° to -45° (n = 6) Group 3: -46° or more (n = 5). The average KFC improved from -38° to -24°. The improvement was 14° (P < 0.001). The average KFC improvement was 9° in group 1, 17° in group 2, and 23° in group 3. There was a high correlation between the improvement in KFC and the total score of the questionnaire R = 0.77. Treatment of KFC with BTX-A improves knee-related functional activities, with the advantage of being a low-cost procedure and easy to apply. © 2015 John Wiley & Sons Ltd.

Implant preloading in extension reduces spring length change in dynamic intraligamentary stabilization: a biomechanical study on passive kinematics of the knee.

PubMed

Häberli, Janosch; Voumard, Benjamin; Kösters, Clemens; Delfosse, Daniel; Henle, Philipp; Eggli, Stefan; Zysset, Philippe

2018-06-01

Dynamic intraligamentary stabilization (DIS) is a primary repair technique for acute anterior cruciate ligament (ACL) tears. For internal bracing of the sutured ACL, a metal spring with 8 mm maximum length change is preloaded with 60-80 N and fixed to a high-strength polyethylene braid. The bulky tibial hardware results in bone loss and may cause local discomfort with the necessity of hardware removal. The technique has been previously investigated biomechanically; however, the amount of spring shortening during movement of the knee joint is unknown. Spring shortening is a crucial measure, because it defines the necessary dimensions of the spring and, therefore, the overall size of the implant. Seven Thiel-fixated human cadaveric knee joints were subjected to passive range of motion (flexion/extension, internal/external rotation in 90° flexion, and varus/valgus stress in 0° and 20° flexion) and stability tests (Lachman/KT-1000 testing in 0°, 15°, 30°, 60°, and 90° flexion) in the ACL-intact, ACL-transected, and DIS-repaired state. Kinematic data of femur, tibia, and implant spring were recorded with an optical measurement system (Optotrak) and the positions of the bone tunnels were assessed by computed tomography. Length change of bone tunnel distance as a surrogate for spring shortening was then computed from kinematic data. Tunnel positioning in a circular zone with r = 5 mm was simulated to account for surgical precision and its influence on length change was assessed. Over all range of motion and stability tests, spring shortening was highest (5.0 ± 0.2 mm) during varus stress in 0° knee flexion. During flexion/extension, spring shortening was always highest in full extension (3.8 ± 0.3 mm) for all specimens and all simulations of bone tunnels. Tunnel distance shortening was highest (0.15 mm/°) for posterior femoral and posterior tibial tunnel positioning and lowest (0.03 mm/°) for anterior femoral and anterior tibial tunnel positioning. During passive flexion/extension, the highest spring shortening was consistently measured in full extension with a continuous decrease towards flexion. If preloading of the spring is performed in extension, the spring can be downsized to incorporate a maximum length change of 5 mm resulting in a smaller implant with less bone sacrifice and, therefore, improved conditions in case of revision surgery.

Use of embedded strain gages for the in-vitro study of proximal tibial cancellous bone deformation during knee flexion-extension movement: development, reproducibility and preliminary results of feasibility after frontal low femoral osteotomy

PubMed Central

2011-01-01

Background This paper reports the development of an in-vitro technique allowing quantification of relative (not absolute) deformations measured at the level of the cancellous bone of the tibial proximal epiphysis (CBTPE) during knee flexion-extension. This method has been developed to allow a future study of the effects of low femoral osteotomies consequence on the CBTPE. Methods Six strain gages were encapsulated in an epoxy resin solution to form, after resin polymerisation, six measurement elements (ME). The latter were inserted into the CBTPE of six unembalmed specimens, just below the tibial plateau. Knee motion data were collected by three-dimensional (3D) electrogoniometry during several cycles of knee flexion-extension. Intra- and inter-observer reproducibility was estimated on one specimen for all MEs. Intra-specimen repeatability was calculated to determine specimen's variability and the error of measurement. A varum and valgum chirurgical procedure was realised on another specimen to observed CBTPE deformation after these kind of procedure. Results Average intra-observer variation of the deformation ranged from 8% to 9% (mean coefficient of variation, MCV) respectively for extension and flexion movement. The coefficient of multiple correlations (CMC) ranged from 0.93 to 0.96 for flexion and extension. No phase shift of maximum strain peaks was observed. Inter-observer MCV averaged 23% and 28% for flexion and extension. The CMC were 0.82 and 0.87 respectively for extension and flexion. For the intra-specimen repeatability, the average of mean RMS difference and the mean ICC were calculated only for flexion movement. The mean RMS variability ranged from 7 to 10% and the mean ICC was 0.98 (0.95 - 0.99). A Pearson's correlation coefficient was calculated showing that RMS was independent of signal intensity. For the chirurgical procedure, valgum and varum deviation seems be in agree with the frontal misalignment theory. Conclusions Results show that the methodology is reproducible within a range of 10%. This method has been developed to allow analysis the indirect reflect of deformation variations in CBTPE before and after distal femoral osteotomies. The first results of the valgum and varum deformation show that our methodology allows this kind of measurement and are encourageant for latter studies. It will therefore allow quantification and enhance the understanding of the effects of this kind of surgery on the CBTPE loading. PMID:21371297

Use of embedded strain gages for the in-vitro study of proximal tibial cancellous bone deformation during knee flexion-extension movement: development, reproducibility and preliminary results of feasibility after frontal low femoral osteotomy.

PubMed

Sobczak, Stéphane; Salvia, Patrick; Dugailly, Pierre-Michel; Lefèvre, Philippe; Feipel, Véronique; Van Sint Jan, Serge; Rooze, Marcel

2011-03-03

This paper reports the development of an in-vitro technique allowing quantification of relative (not absolute) deformations measured at the level of the cancellous bone of the tibial proximal epiphysis (CB(TPE)) during knee flexion-extension. This method has been developed to allow a future study of the effects of low femoral osteotomies consequence on the CB(TPE). Six strain gages were encapsulated in an epoxy resin solution to form, after resin polymerisation, six measurement elements (ME). The latter were inserted into the CB(TPE) of six unembalmed specimens, just below the tibial plateau. Knee motion data were collected by three-dimensional (3D) electrogoniometry during several cycles of knee flexion-extension. Intra- and inter-observer reproducibility was estimated on one specimen for all MEs. Intra-specimen repeatability was calculated to determine specimen's variability and the error of measurement. A varum and valgum chirurgical procedure was realised on another specimen to observed CB(TPE) deformation after these kind of procedure. Average intra-observer variation of the deformation ranged from 8% to 9% (mean coefficient of variation, MCV) respectively for extension and flexion movement. The coefficient of multiple correlations (CMC) ranged from 0.93 to 0.96 for flexion and extension. No phase shift of maximum strain peaks was observed. Inter-observer MCV averaged 23% and 28% for flexion and extension. The CMC were 0.82 and 0.87 respectively for extension and flexion. For the intra-specimen repeatability, the average of mean RMS difference and the mean ICC were calculated only for flexion movement. The mean RMS variability ranged from 7 to 10% and the mean ICC was 0.98 (0.95-0.99). A Pearson's correlation coefficient was calculated showing that RMS was independent of signal intensity. For the chirurgical procedure, valgum and varum deviation seems be in agree with the frontal misalignment theory. Results show that the methodology is reproducible within a range of 10%. This method has been developed to allow analysis the indirect reflect of deformation variations in CB(TPE) before and after distal femoral osteotomies. The first results of the valgum and varum deformation show that our methodology allows this kind of measurement and are encourageant for latter studies. It will therefore allow quantification and enhance the understanding of the effects of this kind of surgery on the CB(TPE) loading.

Experimental knee joint pain during strength training and muscle strength gain in healthy subjects: a randomized controlled trial.

PubMed

Sørensen, T J; Langberg, H; Hodges, P W; Bliddal, H; Henriksen, M

2012-01-01

Knee joint pain and reduced quadriceps strength are cardinal symptoms in many knee pathologies. In people with painful knee pathologies, quadriceps exercise reduces pain, improves physical function, and increases muscle strength. A general assumption is that pain compromises muscle function and thus may prevent effective rehabilitation. This study evaluated the effects of experimental knee joint pain during quadriceps strength training on muscle strength gain in healthy individuals. Twenty-seven healthy untrained volunteers participated in a randomized controlled trial of quadriceps strengthening (3 times per week for 8 weeks). Participants were randomized to perform resistance training either during pain induced by injections of painful hypertonic saline (pain group, n = 13) or during a nonpainful control condition with injection of isotonic saline (control group, n = 14) into the infrapatellar fat pad. The primary outcome measure was change in maximal isokinetic muscle strength in knee extension/flexion (60, 120, and 180 degrees/second). The group who exercised with pain had a significantly larger improvement in isokinetic muscle strength at all angular velocities of knee extension compared to the control group. In knee flexion there were improvements in isokinetic muscle strength in both groups with no between-group differences. Experimental knee joint pain improved the training-induced gain in muscle strength following 8 weeks of quadriceps training. It remains to be studied whether knee joint pain has a positive effect on strength gain in patients with knee pathology. Copyright © 2012 by the American College of Rheumatology.

The relationship between leg preference and knee mechanics during sidestepping in collegiate female footballers.

PubMed

Brown, Scott R; Wang, Henry; Dickin, D Clark; Weiss, Kaitlyn J

2014-11-01

This study examined the relationship between leg preference and knee mechanics in females during sidestepping. Three-dimensional data were recorded on 16 female collegiate footballers during a planned 45° sidestep manoeuvre with their preferred and non-preferred kicking leg. Knee kinematics and kinetics during initial contact, weight acceptance, peak push-off, and final push-off phases of sidestepping were analysed in both legs. The preferred leg showed trivial to small increases (ES = 0.19-0.36) in knee flexion angle at initial contact, weight acceptance, and peak push-off, and small increases (ES = 0.21-0.34) in peak power production and peak knee extension velocity. The non-preferred leg showed a trivial increase (ES = 0.10) in knee abduction angle during weight acceptance; small to moderate increases (ES = 0.22-0.64) in knee internal rotation angle at weight acceptance, peak push-off, and final push-off; a small increase (ES = 0.22) in knee abductor moment; and trivial increases (ES = 0.09-0.14) in peak power absorption and peak knee flexion velocity. The results of this study show that differences do exist between the preferred and non-preferred leg in females. The findings of this study will increase the knowledge base of anterior cruciate ligament injury in females and can aid in the design of more appropriate neuromuscular, plyometric, and strength training protocols for injury prevention.

Posterior Tibial Slope Angle Correlates With Peak Sagittal and Frontal Plane Knee Joint Loading During Robotic Simulations of Athletic Tasks.

PubMed

Bates, Nathaniel A; Nesbitt, Rebecca J; Shearn, Jason T; Myer, Gregory D; Hewett, Timothy E

2016-07-01

Tibial slope angle is a nonmodifiable risk factor for anterior cruciate ligament (ACL) injury. However, the mechanical role of varying tibial slopes during athletic tasks has yet to be clinically quantified. To examine the influence of posterior tibial slope on knee joint loading during controlled, in vitro simulation of the knee joint articulations during athletic tasks. Descriptive laboratory study. A 6 degree of freedom robotic manipulator positionally maneuvered cadaveric knee joints from 12 unique specimens with varying tibial slopes (range, -7.7° to 7.7°) through drop vertical jump and sidestep cutting tasks that were derived from 3-dimensional in vivo motion recordings. Internal knee joint torques and forces were recorded throughout simulation and were linearly correlated with tibial slope. The mean (±SD) posterior tibial slope angle was 2.2° ± 4.3° in the lateral compartment and 2.3° ± 3.3° in the medial compartment. For simulated drop vertical jumps, lateral compartment tibial slope angle expressed moderate, direct correlations with peak internally generated knee adduction (r = 0.60-0.65), flexion (r = 0.64-0.66), lateral (r = 0.57-0.69), and external rotation torques (r = 0.47-0.72) as well as inverse correlations with peak abduction (r = -0.42 to -0.61) and internal rotation torques (r = -0.39 to -0.79). Only frontal plane torques were correlated during sidestep cutting simulations. For simulated drop vertical jumps, medial compartment tibial slope angle expressed moderate, direct correlations with peak internally generated knee flexion torque (r = 0.64-0.69) and lateral knee force (r = 0.55-0.74) as well as inverse correlations with peak external torque (r = -0.34 to -0.67) and medial knee force (r = -0.58 to -0.59). These moderate correlations were also present during simulated sidestep cutting. The investigation supported the theory that increased posterior tibial slope would lead to greater magnitude knee joint moments, specifically, internally generated knee adduction and flexion torques. The knee torques that positively correlated with increased tibial slope angle in this investigation are associated with heightened risk of ACL injury. Therefore, the present data indicated that a higher posterior tibial slope is correlated to increased knee loads that are associated with heightened risk of ACL injury. © 2016 The Author(s).

Stiffness after knee arthrotomy: evaluation of prevalence and results after manipulation under anaesthesia.

PubMed

Ipach, I; Schäfer, R; Lahrmann, J; Kluba, T

2011-05-01

The aim of the present study was to determine the prevalence and the effect of manipulation under anaesthesia in patients with Total Knee Arthroplasty (TKA), "revision-knee" and all forms of other intra-articular surgical procedures. We aimed to determine differences in the outcome according to the number of previous surgeries and according to time of manipulation under anaesthesia (MUA). One thousand three hundred and forty-four elective intra-articular surgeries (no trauma cases) were performed at our institution between 2004 and 2009. Fifty-two of them underwent MUA because of postoperative knee stiffness with a flexion less than 90°. The prevalence for stiffness after primary TKA was 4.54%, for revision-knee procedures 5.11%, and for other forms of intra-articular surgery 1.29%. Flexion was statistically significantly improved directly after MUA in the group after primary TKA with a mean gain of 35.13°±17.03°, in the group with revision procedures of 41.31°±9.08° and in the group with other forms of intra-articular surgery of 24.37°±5.21°. Patients with more than two previous operations showed significantly worse results (P=0.039). No statistically significant difference (P=0.307) was seen according to time (>/<30 days) of MUA. MUA is a valuable technique to increase ROM after TKA in patients with stiff knees, for "revision-knees" and all other patients with reduced flexion after different forms of intra-articular knee surgical procedures (excluding trauma cases). The results were similar for early and delayed MUA relative to the last surgery. The patients can therefore undergo conservative treatment (e.g. physiotherapy) before the MUA without the risk of poorer outcome. The results after MUA in patients with many previous operations were significantly worse and so an open/arthroscopic arthrolysis should be discussed earlier for this subgroup. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Calibration of EMG to force for knee muscles is applicable with submaximal voluntary contractions.

PubMed

Doorenbosch, Caroline A M; Joosten, Annemiek; Harlaar, Jaap

2005-08-01

In this study, the influence of using submaximal isokinetic contractions about the knee compared to maximal voluntary contractions as input to obtain the calibration of an EMG-force model for knee muscles is investigated. Isokinetic knee flexion and extension contractions were performed by healthy subjects at five different velocities and at three contraction levels (100%, 75% and 50% of MVC). Joint angle, angular velocity, joint moment and surface EMG of five knee muscles were recorded. Individual calibration values were calculated according to [C.A.M. Doorenbosch, J. Harlaar, A clinically applicable EMG-force model to quantify active stabilization of the knee after a lesion of the anterior cruciate ligament, Clinical Biomechanics 18 (2003) 142-149] for each contraction level. First, the output of the model, calibrated with the 100% MVC was compared to the actually exerted net knee moment at the dynamometer. Normalized root mean square errors were calculated [A.L. Hof, C.A.N. Pronk, J.A. van Best, Comparison between EMG to force processing and kinetic analysis for the calf muscle moment in walking and stepping, Journal of Biomechanics 20 (1987) 167-187] to compare the estimated moments with the actually exerted moments. Mean RMSD errors ranged from 0.06 to 0.21 for extension and from 0.12 to 0.29 for flexion at the 100% trials. Subsequently, the calibration results of the 50% and 75% MVC calibration procedures were used. A standard signal, representing a random EMG level was used as input in the EMG force model, to compare the three models. Paired samples t-tests between the 100% MVC and the 75% MVC and 50% MVC, respectively, showed no significant differences (p>0.05). The application of submaximal contractions of larger than 50% MVC is suitable to calibrate a simple EMG to force model for knee extension and flexion. This means that in clinical practice, the EMG to force model can be applied by patients who cannot exert maximal force.

Differences in kinematics of single leg squatting between anterior cruciate ligament-injured patients and healthy controls.

PubMed

Yamazaki, J; Muneta, T; Ju, Y J; Sekiya, I

2010-01-01

Seventy to eighty percent of all anterior cruciate ligament (ACL) injuries are due to non-contact injury mechanisms. It has been reported that the majority of injuries due to single leg landing come from valgus positioning of the lower leg. Preventing valgus positioning during single leg landing is expected to help reduce the number of ACL injuries. We found that many ACL-deficient patients cannot perform stable single leg squatting. Therefore, we performed 3D motion analysis of the single-legged half squat for ACL-injured patients to evaluate its significance as a risk factor for ACL injuries. We evaluated the relative angles between the body, thigh, and lower leg using an electromagnetic device during single leg half squatting performed by 63 ACL-injured patients (32 males, 31 females) the day before ACL reconstruction and by 26 healthy control subjects with no knee problems. The uninjured leg of ACL-injured male subjects demonstrated significantly less external knee rotation than that of the dominant leg of the male control. The uninjured leg of ACL-injured female subjects demonstrated significantly more external hip rotation and knee flexion and less hip flexion than that of the dominant leg of the female control. Comparing injured and uninjured legs, the injured leg of male subjects demonstrated significantly less external knee and hip rotation, less knee flexion, and more knee varus than that of the uninjured leg of male subjects. The injured leg of female subjects demonstrated more knee varus than that of the uninjured leg of female subjects. Regarding gender differences, female subjects demonstrated significantly more external hip rotation and knee valgus than male subjects did in both the injured and uninjured legs (P < 0.05). The current kinematic study exhibited biomechanical characteristics of female ACL-injured subjects compared with that of control groups. Kinematic correction during single leg half squat would reduce ACL reinjury in female ACL-injured subjects.

Acute Effects of Hamstring Stretching on Sagittal Spinal Curvatures and Pelvic Tilt

PubMed Central

López-Miñarro, Pedro A.; Muyor, José M.; Belmonte, Felipe; Alacid, Fernando

2012-01-01

The aim of this study was to determine acute effects of hamstring stretching in thoracic and lumbar spinal curvatures and pelvic tilt. Fifty-five adults (29.24 ± 7.41 years) were recruited for this study. Subjects performed a hamstring stretching protocol consisting of four exercises. The session consisted of 3 sets of each exercise and subjects held the position for 20 seconds with a 30-second rest period between sets and exercises. Thoracic and lumbar spinal angles and pelvic tilt were measured with a SpinalMouse in relaxed standing, sit-and-reach test and Macrae & Wright position. Hamstring extensibility was determined by active straight leg raise test and sit-and-reach score. All measures were performed before and immediately after the hamstring stretching protocol. Active straight leg raise angle and sitand-reach score significantly improved immediately after the stretching protocol (p<0.001). Greater anterior pelvic tilt (p<0.001) and lumbar flexion (p<0.05) and a smaller thoracic kyphosis in the sit-and-reach (p<0.001) were found after the stretching protocol. However, stretching produced no significant change on spinal curvatures or pelvic tilt in standing and maximal trunk flexion with knees flexed. In conclusion, static stretching of the hamstring is associated to an immediate change in the sagittal spinal curvatures and pelvic position when performing trunk flexion with knees extended, so that allowing for greater lumbar flexion and anterior pelvic tilt and lower thoracic kyphosis. Hamstring stretching is recommended prior to sport activities involving trunk flexion with the knees straight. PMID:23486214

Knee Kinematics and Joint Moments During Stair Negotiation in Participants With Anterior Cruciate Ligament Deficiency and Reconstruction: A Systematic Review and Meta-Analysis.

PubMed

Hajizadeh, Maryam; Hashemi Oskouei, Alireza; Ghalichi, Farzan; Sole, Gisela

2016-06-01

Biomechanical changes have been reported for patients with anterior cruciate ligament deficiency (ACLD) and anterior cruciate ligament (ACL reconstruction) (ACLR), likely due to loss of stability and changes in proprioception and neuromotor control. This review evaluated kinematics and kinetics of ACLD and ACLR knees, compared with those on the contralateral uninjured sides, as well as and those in asymptomatic controls during stair navigation. This is a systematic review and meta-analysis. Electronic database searches were conducted from their original available dates to January 2015. Studies that included participants with ACLD or ACLR and reported knee joint angles or moments during stair ascent or descent were included. Nine studies met the inclusion criteria, and the methodological quality of these was assessed with a modified Downs and Black checklist. Effect sizes for differences between injured leg and uninjured contralateral leg or controls were calculated, and meta-analyses were performed if two or more studies considered the same variable. Quality assessment showed an average (± standard deviation) of 70.3% ± 7.2%. Meta-analysis showed less knee flexion at initial contact for ACLR knees compared with that in contralateral knees during stair ascent, with a moderate effect size and minimal heterogeneity. Knees with ACLD showed less peak knee flexion compared with that on contralateral sides during stair ascent, with minimal heterogeneity. External knee flexion moments were lower for ACLR compared with those in controls and contralateral sides during ascent and descent, whereas these moments were decreased for the ACLD compared with controls only during ascent. Meta-analysis results exhibited moderate/high heterogeneity or small/trivial effect sizes. Differences for kinematics and kinetics for the ACL-injured knees indicate long-term compensatory and asymmetric movement patterns while ascending and descending stairs. Due to the heterogeneity as well as the small numbers of available studies, the consequences of these differences in terms of long-term function or posttraumatic osteoarthritis need further exploration. Copyright © 2016. Published by Elsevier Inc.

Influence of knee flexion and atraumatic mobilisation of infrapatellar fat pad on incidence and severity of anterior knee pain after tibial nailing.

PubMed

Jankovic, Andrija; Korac, Zelimir; Bozic, Nenad-Bozo; Stedul, Ivan

2013-09-01

We evaluated the incidence and aetiology of anterior knee pain (AKP) in a series of patients that underwent intramedullary nailing for stabilisation of tibial fractures. During the preparation of the entry site no excision of the infrapatellar fat was allowed and electrical haemostasis was kept at the lowest level. Medullary canal was reamed and the nails inserted in position of knee flexion over 100 degrees. All fractures were fixed using medial paratendinous approach. Functional outcome was measured using Lysholm knee score. The knee range of movement and return to previous level of activity were also documented and analysed. Mean follow up was 38.9 months (range 12-84 months). In total 60 patients with 62 tibial shaft fractures were analysed. The mean age at the time of final follow up was 49.4 years (range 20-87). In 22 (35.5%) a newly developed and persisting pain in the anterior region of the operated knee was reported. According to VAP scale, the pain was mild (VAS 1-3) in 12 cases (19.4%) and moderate (VAS 4-6) in 10 (16.1%). In 16 cases (73%) the pain was noticed 6-12 months after injury and subjectively related to return to full range of working and recreational activities. The mean Lysholm knee score in the group without AKP was 90.8. In the AKP group with mild pain it was 88.4 and in the group with moderate AKP it was 79.9. Complete return to previous professional and recreational activities occurred in 49/60 patients (81.7%). Content with the treatment regarding expectations in recovery dynamics and return to desired level of activity was present in 98.3% of patients; one patient was unsatisfied with the treatment. Our results indicate that respecting the physiological motion of Hoffa pad and menisci during knee flexion, accompanied with atraumatic mobilisation of retrotendinous fat, reduces incidence and severity of anterior knee pain following intramedullary fixation of tibial shaft fractures. Copyright © 2013 Elsevier Ltd. All rights reserved.

The collision forces and lower-extremity inter-joint coordination during running.

PubMed

Wang, Li-I; Gu, Chin-Yi; Wang, I-Lin; Siao, Sheng-Wun; Chen, Szu-Ting

2018-06-01

The purpose of this study was to compare the lower extremity inter-joint coordination of different collision forces runners during running braking phase. A dynamical system approach was used to analyse the inter-joint coordination parameters. Data were collected with six infra-red cameras and two force plates. According to the impact peak of the vertical ground reaction force, twenty habitually rearfoot-strike runners were categorised into three groups: high collision forces runners (HF group, n = 8), medium collision forces runners (MF group, n = 5), and low collision forces runners (LF group, n = 7). There were no significant differences among the three groups in the ankle and knee joint angle upon landing and in the running velocity (p > 0.05). The HF group produced significantly smaller deviation phase (DP) of the hip flexion/extension-knee flexion/extension during the braking phase compared with the MF and LF groups (p < 0.05). The DP of the hip flexion/extension-knee flexion/extension during the braking phase correlated negatively with the collision force (p < 0.05). The disparities regarding the flexibility of lower extremity inter-joint coordination were found in high collision forces runners. The efforts of the inter-joint coordination and the risk of running injuries need to be clarified further.

Comparison of 3D Joint Angles Measured With the Kinect 2.0 Skeletal Tracker Versus a Marker-Based Motion Capture System.

PubMed

Guess, Trent M; Razu, Swithin; Jahandar, Amirhossein; Skubic, Marjorie; Huo, Zhiyu

2017-04-01

The Microsoft Kinect is becoming a widely used tool for inexpensive, portable measurement of human motion, with the potential to support clinical assessments of performance and function. In this study, the relative osteokinematic Cardan joint angles of the hip and knee were calculated using the Kinect 2.0 skeletal tracker. The pelvis segments of the default skeletal model were reoriented and 3-dimensional joint angles were compared with a marker-based system during a drop vertical jump and a hip abduction motion. Good agreement between the Kinect and marker-based system were found for knee (correlation coefficient = 0.96, cycle RMS error = 11°, peak flexion difference = 3°) and hip (correlation coefficient = 0.97, cycle RMS = 12°, peak flexion difference = 12°) flexion during the landing phase of the drop vertical jump and for hip abduction/adduction (correlation coefficient = 0.99, cycle RMS error = 7°, peak flexion difference = 8°) during isolated hip motion. Nonsagittal hip and knee angles did not correlate well for the drop vertical jump. When limited to activities in the optimal capture volume and with simple modifications to the skeletal model, the Kinect 2.0 skeletal tracker can provide limited 3-dimensional kinematic information of the lower limbs that may be useful for functional movement assessment.

Reliability, Concurrent Validity, and Minimal Detectable Change for iPhone Goniometer App in Assessing Knee Range of Motion.

PubMed

Mehta, Saurabh P; Barker, Katherine; Bowman, Brett; Galloway, Heather; Oliashirazi, Nicole; Oliashirazi, Ali

2017-07-01

Much of the published works assessing the reliability of smartphone goniometer apps (SG) have poor generalizability since the reliability was assessed in healthy subjects. No research has established the values for standard error of measurement (SEM) or minimal detectable change (MDC) which have greater clinical utility to contextualize the range of motion (ROM) assessed using the SG. This research examined the test-retest reproducibility, concurrent validity, SEM, and MDC values for the iPhone goniometer app (i-Goni; June Software Inc., v.1.1, San Francisco, CA) in assessing knee ROM in patients with knee osteoarthritis or those after total knee replacement. A total of 60 participants underwent data collection which included the assessment of active knee ROM using the i-Goni and the universal goniometer (UG; EZ Read Jamar Goniometer, Patterson Medical, Warrenville, IL), knee muscle strength, and assessment of pain and lower extremity disability using quadruple numeric pain rating scale (Q-NPRS) and lower extremity functional scale (LEFS), respectively. Intraclass correlation coefficients (ICCs) were calculated to assess the reproducibility of the knee ROM assessed using the i-Goni and UG. Bland and Altman technique examined the agreement between these knee ROM. The SEM and MDC values were calculated for i-Goni assessed knee ROM to characterize the error in a single score and the index of true change, respectively. Pearson correlation coefficient examined concurrent relationships between the i-Goni and other measures. The ICC values for the knee flexion/extension ROM were superior for i-Goni (0.97/0.94) compared with the UG (0.95/0.87). The SEM values were smaller for i-Goni assessed knee flexion/extension (2.72/1.18 degrees) compared with UG assessed knee flexion/extension (3.41/1.62 degrees). Similarly, the MDC values were smaller for both these ROM for the i-Goni (6.3 and 2.72 degrees) suggesting smaller change required to infer true change in knee ROM. The i-Goni assessed knee ROM showed expected concurrent relationships with UG, knee muscle strength, Q-NPRS, and the LEFS. In conclusion, the i-Goni demonstrated superior reproducibility with smaller measurement error compared with UG in assessing knee ROM in the recruited cohort. Future research can expand the inquiry for assessing the reliability of the i-Goni to other joints. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Joint angles of the ankle, knee, and hip and loading conditions during split squats.

PubMed

Schütz, Pascal; List, Renate; Zemp, Roland; Schellenberg, Florian; Taylor, William R; Lorenzetti, Silvio

2014-06-01

The aim of this study was to quantify how step length and the front tibia angle influence joint angles and loading conditions during the split squat exercise. Eleven subjects performed split squats with an additional load of 25% body weight applied using a barbell. Each subject's movements were recorded using a motion capture system, and the ground reaction force was measured under each foot. The joint angles and loading conditions were calculated using a cluster-based kinematic approach and inverse dynamics modeling respectively. Increases in the tibia angle resulted in a smaller range of motion (ROM) of the front knee and a larger ROM of the rear knee and hip. The external flexion moment in the front knee/hip and the external extension moment in the rear hip decreased as the tibia angle increased. The flexion moment in the rear knee increased as the tibia angle increased. The load distribution between the legs changed < 25% when split squat execution was varied. Our results describing the changes in joint angles and the resulting differences in the moments of the knee and hip will allow coaches and therapists to adapt the split squat exercise to the individual motion and load demands of athletes.

Isokinetic Leg Strength and Power in Elite Handball Players

PubMed Central

González-Ravé, José M.; Juárez, Daniel; Rubio-Arias, Jacobo A.; Clemente-Suarez, Vicente J; Martinez-Valencia, María A; Abian-Vicen, Javier

2014-01-01

Isokinetic strength evaluation of the knee flexion and extension in concentric mode of contraction is an important part of the comprehensive evaluation of athletes. The aims of this study were to evaluate the isokinetic knee peak torque in both the extension and flexion movement in the dominant and non-dominant leg, and the relationship with jumping performance. Twelve elite male handball players from the top Spanish handball division voluntary participated in the study (age 27.68 ± 4.12 years; body mass 92.89 ± 12.34 kg; body height 1.90 ± 0.05 m). The knee extensor and flexor muscle peak torque of each leg were concentrically measured at 60º/s and 180º/s with an isokinetic dynamometer. The Squat Jump and Countermovement Jump were performed on a force platform to determine power and vertical jump height. Non-significant differences were observed between legs in the isokinetic knee extension (dominant= 2.91 ± 0.53 Nm/kg vs non-dominant = 2.70 ± 0.47 Nm/kg at 60º/s; dominant = 1.90 ± 0.31 Nm/kg vs non-dominant = 1.83 ± 0.29 Nm/kg at 180º/s) and flexion peak torques (dominant = 1.76 ± 0.29 Nm/kg vs non-dominant = 1.72 ± 0.39 Nm/kg at 60º/s; dominant = 1.30 ± 0.23 Nm/kg vs non-dominant = 1.27 ± 0.35 Nm/kg at 180º/s). Low and non-significant correlation coefficients were found between the isokinetic peak torques and vertical jumping performance (SJ = 31.21 ± 4.32 cm; CMJ = 35.89 ± 4.20 cm). Similar isokinetic strength was observed between the legs; therefore, no relationship was found between the isokinetic knee flexion and extension peak torques as well as vertical jumping performance in elite handball players. PMID:25114749

Impact of 10-weeks of yoga practice on flexibility and balance of college athletes

PubMed Central

Polsgrove, M Jay; Eggleston, Brandon M; Lockyer, Roch J

2016-01-01

Background: With clearer evidence of its benefits, coaches, and athletes may better see that yoga has a role in optimizing performance. Aims: To determine the impact of yoga on male college athletes (N = 26). Methods: Over a 10-week period, a yoga group (YG) of athletes (n = 14) took part in biweekly yoga sessions; while a nonyoga group (NYG) of athletes (n = 12) took part in no additional yoga activity. Performance measures were obtained immediately before and after this period. Measurements of flexibility and balance, included: Sit-reach (SR), shoulder flexibility (SF), and stork stand (SS); dynamic measurements consisted of joint angles (JA) measured during the performance of three distinct yoga positions (downward dog [DD]; right foot lunge [RFL]; chair [C]). Results: Significant gains were observed in the YG for flexibility (SR, P = 0.01; SF, P = 0.03), and balance (SS, P = 0.05). No significant differences were observed in the NYG for flexibility and balance. Significantly, greater JA were observed in the YG for: RFL (dorsiflexion, l-ankle; P = 0.04), DD (extension, r-knee, P = 0.04; r-hip; P = 0.01; flexion, r-shoulder; P = 0.01) and C (flexion, r-knee; P = 0.01). Significant JA differences were observed in the NYG for: DD (flexion, r-knee, P = 0.01: r-hip, P = 0.05; r-shoulder, P = 0.03) and C (flexion r-knee, P = 0.01; extension, r-shoulder; P = 0.05). A between group comparison revealed the significant differences for: RFL (l-ankle; P = 0.01), DD (r-knee, P = 0.01; r-hip; P = 0.01), and C (r-shoulder, P = 0.02). Conclusions: Results suggest that a regular yoga practice may increase the flexibility and balance as well as whole body measures of male college athletes and therefore, may enhance athletic performances that require these characteristics. PMID:26865768

Isokinetic leg strength and power in elite handball players.

PubMed

González-Ravé, José M; Juárez, Daniel; Rubio-Arias, Jacobo A; Clemente-Suarez, Vicente J; Martinez-Valencia, María A; Abian-Vicen, Javier

2014-06-28

Isokinetic strength evaluation of the knee flexion and extension in concentric mode of contraction is an important part of the comprehensive evaluation of athletes. The aims of this study were to evaluate the isokinetic knee peak torque in both the extension and flexion movement in the dominant and non-dominant leg, and the relationship with jumping performance. Twelve elite male handball players from the top Spanish handball division voluntary participated in the study (age 27.68 ± 4.12 years; body mass 92.89 ± 12.34 kg; body height 1.90 ± 0.05 m). The knee extensor and flexor muscle peak torque of each leg were concentrically measured at 60º/s and 180º/s with an isokinetic dynamometer. The Squat Jump and Countermovement Jump were performed on a force platform to determine power and vertical jump height. Non-significant differences were observed between legs in the isokinetic knee extension (dominant= 2.91 ± 0.53 Nm/kg vs non-dominant = 2.70 ± 0.47 Nm/kg at 60º/s; dominant = 1.90 ± 0.31 Nm/kg vs non-dominant = 1.83 ± 0.29 Nm/kg at 180º/s) and flexion peak torques (dominant = 1.76 ± 0.29 Nm/kg vs non-dominant = 1.72 ± 0.39 Nm/kg at 60º/s; dominant = 1.30 ± 0.23 Nm/kg vs non-dominant = 1.27 ± 0.35 Nm/kg at 180º/s). Low and non-significant correlation coefficients were found between the isokinetic peak torques and vertical jumping performance (SJ = 31.21 ± 4.32 cm; CMJ = 35.89 ± 4.20 cm). Similar isokinetic strength was observed between the legs; therefore, no relationship was found between the isokinetic knee flexion and extension peak torques as well as vertical jumping performance in elite handball players.

Specificity of the femoral slump test for the assessment of experimentally induced anterior knee pain.

PubMed

Lai, Weng-Hang; Shih, Yi-Fen; Lin, Pei-Ling; Chen, Wen-Yin; Ma, Hsiao-Li

2012-12-01

To assess the specificity of the femoral slump test (FST) when assessing experimentally induced anterior knee pain. Cross-sectional, exploratory study. Research laboratory. Asymptomatic subjects (N=12; 6 men; 6 women) for the study. An experimental pain model was used to simulate anterior knee pain by injecting .25 mL of hypertonic saline solution (5% NaCl) into the medial infrapatellar fat pad. Not applicable. The changes in pain intensity and diameter after applying the structure differential maneuver (neck flexion/extension) during the FST were recorded and analyzed. Results revealed that the structure differential maneuver of the FST did not alter the pain intensity or diameter in 9 (neck extension) and 10 (neck flexion) out of 12 subjects, which meant that the FST provided appropriate testing responses in 75% to 83% cases when the anterior knee pain did not originate in neural tissues. The FST had a specificity of more than .75 when detecting nerve mechanosensitivity problems of anterior knee pain. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Effects of static stretching of knee musculature on patellar alignment and knee functional disability in male patients diagnosed with knee extension syndrome: A single-group, pretest-posttest trial.

PubMed

Pourahmadi, Mohammad Reza; Ebrahimi Takamjani, Ismail; Hesampour, Kazem; Shah-Hosseini, Gholam Reza; Jamshidi, Ali Ashraf; Shamsi, Mohammad Bagher

2016-04-01

Knee extension (Kext) syndrome is based on movement system impairments and is described as knee pain associated with quadriceps stiffness. To investigate the effects of 3 times per week for 4 weeks static stretching of knee musculature on patellar alignment and knee functional disability in male Kext syndrome patients. A single-group, pretest-posttest clinical trial. Hazrat-e-Rasoul Akram Hospital. Forty-six male Kext syndrome patients aged 18-35 years. Knee functional disability was assessed by the Kujala questionnaire. Patellar tilt was assessed using the skyline view X-ray. In addition, patella alta was assessed by X-ray using the Insall-Salvati ratio. After intervention, changes in knee flexion-extension range of motion (ROM) and hip adduction were assessed by goniometer and inclinometer. Changes in patellar tilt and patella alta were evaluated. Correlations between muscles length, patellar tilt and knee functional disability were also evaluated. The mean of patellar tilt in male Kext syndrome patients was 15.19°. Only the correlation between rectus femoris shortness and patellar tilt (P = 0.002) and the correlation between rectus femoris shortness and knee functional disability (P = 0.037) were significant. Patella alta was not severe in male Kext syndrome patients (1.28 ± 0.10). Knee flexion-extension ROM and femoral adduction increased significantly after a 12-session stretching programme (P < 0.0001). The results demonstrated that rectus femoris shortness had higher correlation with patellar tilt and knee functional disability than iliotibial band and hamstring shortness. Stretching was effective in reducing patellar tilt, patella alta, knee functional disability, increasing knee ROM and hip adduction in these patients. Copyright © 2015 Elsevier Ltd. All rights reserved.

A method to differentiate the causes of stiff-knee gait in stroke patients.

PubMed

Campanini, I; Merlo, A; Damiano, B

2013-06-01

Stiff-knee gait (SKG) is a common abnormal gait pattern in patients after stroke characterized by insufficient knee flexion (KF) during swing. Overactivity of the rectus femoris (RF) is considered the primary cause of SKG. Inadequate push-off has been indicated as an additional cause in the recent literature, as KF depends on knee flexion velocity in preswing (KFV). We used the peak of vertical acceleration of the malleolus (PMVA) as a kinematic-based indirect measure of push-off and studied its relationship with KF and KFV in a sample of 20 healthy subjects walking fast (v = 95 ± 5%heights(-1)), at self-selected speed (v = 74 ± 5%heights(-1)), slow (v = 54 ± 6%heights(-1)) and very slow (v = 38 ± 5%heights(-1)) and in a sample of 52 stroke patients with SKG (age 60 ± 11, v = 20 ± 11%heights(-1)). In healthy subjects PMVA occurred before knee flexion acceleration (p<0.001) and hip flexion acceleration (p<0.001). KF appeared as a bottom-up mechanism driven by the ankle push-off. From a regression analysis, the PMVA-KFV cause-effect relationship resulted strictly linear, with R(2) = 0.967, KFV = 0+7.1×PMVA, P<0.0001. Data from SKG patients were compared to this normal cause-effect model. For 44/52 patients the reduced KFV was combined with lack of push-off. Data from 8/52 patients only were statistically outside the 95%CI of the model, thus requiring for a braking mechanism to explain KFV reduction. In stroke adults of our sample the push-off impairment (85% of cases) and not the inappropriate knee extension moment produced by the thigh muscles was the primary cause of SKG. This result could explain the low average efficacy (<10°) of focal and surgical treatments at the quadriceps. The presented model could be used to differentiate the primary cause of SKG between inadequate push-off and braking activity of the thigh muscles, thus increasing the effectiveness of the selected treatment. Copyright © 2013 Elsevier B.V. All rights reserved.

Investigation of the Effects of High-Intensity, Intermittent Exercise and Unanticipation on Trunk and Lower Limb Biomechanics During a Side-Cutting Maneuver Using Statistical Parametric Mapping.

PubMed

Whyte, Enda F; Richter, Chris; OʼConnor, Siobhan; Moran, Kieran A

2018-06-01

Whyte, EF, Richter, C, O'Connor, S, and Moran, KA. Investigation of the effects of high-intensity, intermittent exercise and unanticipation on trunk and lower limb biomechanics during a side-cutting maneuver using statistical parametric mapping. J Strength Cond Res 32(6): 1583-1593, 2018-Anterior cruciate ligament (ACL) injuries frequently occur during side-cutting maneuvers when fatigued or reacting to the sporting environment. Trunk and hip biomechanics are proposed to influence ACL loading during these activities. However, the effects of fatigue and unanticipation on the biomechanics of the kinetic chain may be limited by traditional discrete point analysis. We recruited 28 male, varsity, Gaelic footballers (21.7 ± 2.2 years; 178.7 ± 14.6 m; 81.8 ± 11.4 kg) to perform anticipated and unanticipated side-cutting maneuvers before and after a high-intensity, intermittent exercise protocol (HIIP). Statistical parametric mapping (repeated-measures analysis of varience) identified differences in phases of trunk and stance leg biomechanics during weight acceptance. Unanticipation resulted in less trunk flexion (p < 0.001) and greater side flexion away from the direction of cut (p < 0.001). This led to smaller (internal) knee flexor and greater (internal) knee extensor (p = 0.002-0.007), hip adductor (p = 0.005), and hip external rotator (p = 0.007) moments. The HIIP resulted in increased trunk flexion (p < 0.001) and side flexion away from the direction of cut (p = 0.038), resulting in smaller (internal) knee extensor moments (p = 0.006). One interaction effect was noted demonstrating greater hip extensor moments in the unanticipated condition post-HIIP (p = 0.025). Results demonstrate that unanticipation resulted in trunk kinematics considered an ACL injury risk factor. A subsequent increase in frontal and transverse plane hip loading and sagittal plane knee loading was observed, which may increase ACL strain. Conversely, HIIP-induced trunk kinematic alterations resulted in reduced sagittal plane knee and subsequent ACL loading. Therefore, adequate hip and knee control is important during unanticipated side-cutting maneuvers.

Effects of sex and obesity on gait biomechanics before and six months after total knee arthroplasty: A longitudinal cohort study.

PubMed

Paterson, K L; Sosdian, L; Hinman, R S; Wrigley, T V; Kasza, J; Dowsey, M; Choong, P; Bennell, K L

2018-03-01

Gait biomechanics, sex, and obesity can contribute to suboptimal outcomes from primary total knee arthroplasty. The aims of this study were to i) determine if sex and/or obesity influence the amount of change in gait biomechanics from pre-surgery to six months post-surgery and; ii) assess if gait returns to normal in men and women. Three-dimensional gait analysis was performed on 43 patients undergoing primary total knee arthroplasty for knee osteoarthritis (pre- and six months post-operative) and 40 asymptomatic controls. Mixed linear regression models were fit to assess which factors influenced change in gait biomechanics within the arthroplasty cohort, and interaction terms were included to assess if biomechanics returned to normal following surgery. Male peak knee adduction moment (p < 0.001) and impulse (p < 0.001) decreased six months following arthroplasty, whilst gait in women remained unchanged after surgery. Obesity did not influence gait changes in men or women. Gait of female arthroplasty participants did not differ from female controls after surgery except for sagittal plane knee range of motion (p = 0.003), whilst men differed from controls for peak knee adduction moment (p = 0.011), knee range of motion (p < 0.001), and peak knee flexion moment (p < 0.001). Sex, but not obesity, influenced changes in gait biomechanics after arthroplasty. Men retained abnormal gait patterns after surgery, whilst women did not. Further research should determine the long-term implications of gait abnormalities seen in men after arthroplasty. Copyright © 2018 Elsevier B.V. All rights reserved.

An Intelligent Remote Monitoring System for Total Knee Arthroplasty Patients.

PubMed

Msayib, Yunus; Gaydecki, Patrick; Callaghan, Michael; Dale, Nicola; Ismail, Sheheera

2017-06-01

For the first six weeks following total knee arthroplasty (TKA), a patient will attend an outpatient clinic typically seen twice weekly. Here, an exercise regime is performed and improvement assessed using a hand held goniometer that measures the maximum angle of knee flexion, an important metric of progress. Additionally a series of daily exercises is performed at home, recorded in a diary. This protocol has problems. Patients must attend the hospital with assistance since they are not permitted to drive for six weeks following the procedure; appointments are sometimes missed; there are occasionally not enough physiotherapy appointment available; furthermore, it is difficult to be sure that patients are compliant with their exercises at home. The economic and social costs are therefore significant both to the patient and the health service. We describe here an automatic system that performs the monitoring of knee flexion within a domestic environment rather than in a hospital setting. It comprises a master and slave sensor unit that attach using Velcro straps to the thigh and shin above and below the operation wound. The patient performs the prescribed knee exercises whilst wearing the device, during which time it measures and records the angles of knee flexion. The device utilises the Global System for Mobile Communications (GSM) infrastructure to transmit data through the Internet to a secure hospital-based server using an on-board GSM modem. The clinician is then able to view and interpret the information from any computer with internet access and the software. The system does not require the patient to possess a mobile telephone, a computer, or have internet access; the necessary communications technology is completely integrated into the device.

Collateral ligament strains during knee joint laxity evaluation before and after TKA.

PubMed

Delport, Hendrik; Labey, Luc; De Corte, Ronny; Innocenti, Bernardo; Vander Sloten, Jos; Bellemans, Johan

2013-08-01

Passive knee stability is provided by the soft tissue envelope. There is consensus among orthopedic surgeons that good outcome in Total Knee Arthroplasty requires equal tension in the medial/lateral compartment of the knee joint, as well as equal tension in the flexion/extension gap. The purpose of this study was to quantify the ligament laxity in the normal non-arthritic knee before and after Posterior-Stabilized Total Knee Arthroplasty. We hypothesized that the Medial/Lateral Collateral Ligament shows minimal changes in length when measured directly by extensometers in the native human knee during varus/valgus laxity testing. We also hypothesized that due to differences in material properties and surface geometry, native laxity is difficult to reconstruct using a Posterior-Stabilized Total Knee. Six specimens were used to perform this in vitro cadaver test using extensometers to provide numerical values for laxity and varus-valgus tilting in the frontal plane. This study enabled a precise measurement of varus-valgus laxity as compared with the clinical assessment. The strains in both ligaments in the replaced knee were different from those in the native knee. Both ligaments were stretched in extension, in flexion the Medial Collateral Ligament tends to relax and the Lateral Collateral Ligament remains tight. As material properties and surface geometry of the replaced knee add stiffness to the joint, we recommend to avoid overstuffing the joint, when using this type of Posterior-Stabilized Total Knee Arthroplasty, in order to obtain varus/valgus laxity close to the native joint. Copyright © 2013 Elsevier Ltd. All rights reserved.

Manipulation under anaesthesia post total knee replacement: long term follow up.

PubMed

Yeoh, David; Nicolaou, Nick; Goddard, Richard; Willmott, Henry; Miles, Kim; East, Debra; Hinves, Barry; Shepperd, John; Butler-Manuel, Adrian

2012-08-01

A reduced range of motion post total knee replacement (TKR) is a recognised problem. Manipulation under anaesthesia (MUA) is commonly performed in the stiff post-operative TKR. Long-term results are variable in the literature. We retrospectively reviewed, prospectively collected data on 48 patients followed up since 1996 from one centre, over an average of 7.5 years, (range 1 to 10 years) and report on the long-term results. During the study period 2.3% of TKRs underwent MUA. The mean time to MUA post TKR was 12.3 weeks (range 3 to 48). Pre MUA, the mean flexion was 53°. The mean immediate passive flexion post MUA was 97°, an improvement of 44° (Range 10° to 90°, p<0.05). By 1year, the mean flexion was 87°, an improvement of 34°, (range -15° to 70°, p<0.05). At 10 years the mean flexion was 86°, (range 55° to 100°, p<0.05). We found no difference in the gain in range of motion (ROM) between knees manipulated before or after 12 weeks. Additionally, the gain was no different in stiff knees with a pre TKR ROM <90°, compared to a pre TKR ROM >90°. There were no complications as a result of MUA. However, one patient was eventually revised at 2 years secondary to low grade infection. Our findings show that MUA is a safe and effective method at improving the ROM in a stiff post-operative TKR. The improvement is maintained in the long term irrespective of time to MUA and range of motion pre TKR. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Which patellofemoral joint imaging features are associated with patellofemoral pain? Systematic review and meta-analysis.

PubMed

Drew, B T; Redmond, A C; Smith, T O; Penny, F; Conaghan, P G

2016-02-01

To review the association between patellofemoral joint (PFJ) imaging features and patellofemoral pain (PFP). A systematic review of the literature from AMED, CiNAHL, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PEDro, EMBASE and SPORTDiscus was undertaken from their inception to September 2014. Studies were eligible if they used magnetic resonance imaging (MRI), computed tomography (CT), ultrasound (US) or X-ray (XR) to compare PFJ features between a PFP group and an asymptomatic control group in people <45 years of age. A pooled meta-analysis was conducted and data was interpreted using a best evidence synthesis. Forty studies (all moderate to high quality) describing 1043 people with PFP and 839 controls were included. Two features were deemed to have a large standardised mean difference (SMD) based on meta-analysis: an increased MRI bisect offset at 0° knee flexion under load (0.99; 95% CI: 0.49, 1.49) and an increased CT congruence angle at 15° knee flexion, both under load (1.40 95% CI: 0.04, 2.76) and without load (1.24; 95% CI: 0.37, 2.12). A medium SMD was identified for MRI patella tilt and patellofemoral contact area. Limited evidence was found to support the association of other imaging features with PFP. A sensitivity analysis showed an increase in the SMD for patella bisect offset at 0° knee flexion (1.91; 95% CI: 1.31, 2.52) and patella tilt at 0° knee flexion (0.99; 95% CI: 0.47, 1.52) under full weight bearing. Certain PFJ imaging features were associated with PFP. Future interventional strategies may be targeted at these features. CRD 42014009503. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Kinematic adaptations during running: effects of footwear, surface, and duration.

PubMed

Hardin, Elizabeth C; van den Bogert, Antonie J; Hamill, Joseph

2004-05-01

Repetitive impacts encountered during locomotion may be modified by footwear and/or surface. Changes in kinematics may occur either as a direct response to altered mechanical conditions or over time as active adaptations. : To investigate how midsole hardness, surface stiffness, and running duration influence running kinematics. In the first of two experiments, 12 males ran at metabolic steady state under six conditions; combinations of midsole hardness (40 Shore A, 70 Shore A), and surface stiffness (100 kN x m, 200 kN x m, and 350 kN x m). In the second experiment, 10 males ran for 30 min on a 12% downhill grade. In both experiments, subjects ran at 3.4 m x s on a treadmill while 2-D hip, knee, and ankle kinematics were determined using high-speed videography (200 Hz). Oxygen cost and heart rate data were also collected. Kinematic adaptations to midsole, surface, and running time were studied. Stance time, stride cycle time, and maximal knee flexion were invariant across conditions in each experiment. Increased midsole hardness resulted in greater peak ankle dorsiflexion velocity (P = 0.0005). Increased surface stiffness resulted in decreased hip and knee flexion at contact, reduced maximal hip flexion, and increased peak angular velocities of the hip, knee, and ankle. Over time, hip flexion at contact decreased, plantarflexion at toe-off increased, and peak dorsiflexion and plantarflexion velocity increased. Lower-extremity kinematics adapted to increased midsole hardness, surface stiffness, and running duration. Changes in limb posture at impact were interpreted as active adaptations that compensate for passive mechanical effects. The adaptations appeared to have the goal of minimizing metabolic cost at the expense of increased exposure to impact shock.

Profiling Isokinetic Strength by Leg Preference and Position in Rugby Union Athletes.

PubMed

Brown, Scott R; Brughelli, Matt; Bridgeman, Lee A

2016-05-01

Muscle imbalances aid in the identification of athletes at risk for lower-extremity injury. Little is known regarding the influence that leg preference or playing position may have on lower-extremity muscle strength and asymmetry. To investigate lower-extremity strength profiles in rugby union athletes and compare isokinetic knee- and hip-strength variables between legs and positions. Thirty male academy rugby union athletes, separated into forwards (n = 15) and backs (n = 15), participated in this cross-sectional analysis. Isokinetic dynamometry was used to evaluate peak torque, angle of peak torque, and strength ratios of the preferred and nonpreferred legs during seated knee extension/flexion and supine hip extension/flexion at 60°/s. Backs were older (ES = 1.6) but smaller in stature (ES = -0.47) and body mass (ES = -1.3) than the forwards. The nonpreferred leg was weaker than the preferred leg for forwards during extension (ES = -0.37) and flexion (ES = -0.21) actions and for backs during extension (ES = -0.28) actions. Backs were weaker at the knee than forwards in the preferred leg during extension (ES = -0.50) and flexion (ES = -0.66) actions. No differences were observed in strength ratios between legs or positions. Backs produced peak torque at longer muscle lengths in both legs at the knee (ES = -0.93 to -0.94) and hip (ES = -0.84 to -1.17) than the forwards. In this sample of male academy rugby union athletes, the preferred leg and forwards displayed superior strength compared with the nonpreferred leg and backs. These findings highlight the importance of individualized athletic assessments to detect crucial strength differences in male rugby union athletes.

The influence of intraoperative soft tissue balance on patellar pressure in posterior-stabilized total knee arthroplasty.

PubMed

Matsumoto, Tomoyuki; Shibanuma, Nao; Takayama, Koji; Sasaki, Hiroshi; Ishida, Kazunari; Matsushita, Takehiko; Kuroda, Ryosuke; Kurosaka, Masahiro

2016-06-01

Appropriate soft tissue balance is essential for the success of total knee arthroplasty (TKA), and assessment with an offset-type tensor provides useful information about the femorotibial (FT) joint. The purpose of the study was to investigate the relationship between intraoperative soft tissue balance and patellar pressure at both medial and lateral sides. Thirty varus-type osteoarthritis patients who received mobile-bearing posterior-stabilized TKAs were enrolled in the study. Using the tensor, soft tissue balance, including joint component gap and varus ligament balance, was recorded at 0°, 10°, 30°, 60°, 90°, 120°, and 135° with patellofemoral (PF) joint reduction and femoral component placement. Following final prostheses implanted with appropriate insert, the medial and lateral patellar pressures were measured at each flexion angle. A simple regression analysis was performed between each patellar pressure, parameter of soft tissue balance, and postoperative flexion angle. Both lateral and medial patellar pressures increased with flexion. The lateral patellar pressure was significantly higher than the medial patellar pressure at 60°, 90°, and 135° of flexion (p<0.05). The lateral patellar pressure inversely correlated with the varus ligament balance at 60° and 90° of flexion (p<0.05). The lateral patellar pressure at 120° and 135° of flexion inversely correlated with the postoperative flexion angle (p<0.05). Soft tissue balance influenced patellar pressure. In particular, a reduced lateral patellar pressure was found at the lateral laxity at flexion, leading to high postoperative flexion angle. III. Copyright © 2016 Elsevier B.V. All rights reserved.

Mobile vs. fixed bearing unicondylar knee arthroplasty: A randomized study on short term clinical outcomes and knee kinematics.

PubMed

Li, Ming G; Yao, Felix; Joss, Brendan; Ioppolo, James; Nivbrant, Bo; Wood, David

2006-10-01

The literature contains limited yet controversial information regarding whether a fixed or a mobile bearing implant should be used in unicompartmental knee arthroplasty (UKA). This randomized study was to further document the performance and comparison of the two designs. Fifty-six knees in 48 patients (mean age of 72 years) undergoing medial UKA were randomized into a fixed bearing (Miller/Galante) or a mobile bearing (Oxford) UKA. The 2 year clinical outcomes (clinical scores), radiographic findings, and weight bearing knee kinematics (assessed using RSA) were compared between the two groups. The mobile bearing knees displayed a larger and an incrementally increased tibial internal rotation (4.3 degrees, 7.6 degrees, 9.5 degrees vs. 3.0 degrees, 3.0 degrees, 4.2 degrees respectively at 30 degrees, 60 degrees, 90 degrees of knee flexion) compared to the fixed ones. The medial femoral condyle in the mobile bearing knees remained 2 mm from the initial position vs. a 4.2 mm anterior translation in the fixed bearing knees during knee flexion. The contact point in the mobile bearing implant moved 2 mm posteriorly vs. a 6 mm anterior movement in the other group. The mobile bearing knees had a lower incidence of radiolucency at the bone implant interface (8% vs. 37%, p < 0.05). The incidence of lateral compartment OA and progression of OA at patello-femoral joint were equal. No differences were found regarding Knee Society Scores, WOMAC, and SF-36 scores (p > 0.05). This study indicates that mobile bearing knees had a better kinematics, a lower incidence of radiolucency but not yet a better knee function at 2 years.

A Biomechanical Study of Posteromedial Tibial Plateau Fracture Stability: Do They All Require Fixation?

PubMed

Cuéllar, Vanessa G; Martinez, Danny; Immerman, Igor; Oh, Cheongeun; Walker, Peter S; Egol, Kenneth A

2015-07-01

Although the posteromedial fragment in tibial plateau fractures is often considered unstable, biomechanical evidence supporting this view is lacking. We aimed to evaluate the stability of the fragment in a cadaver model. Our hypothesis was that under the expected small axial force during rehabilitation and the combined effects of this force with shear force, internal rotation torque, and varus moment, the most common posteromedial tibial fragment morphology could maintain stability in early flexion. Axial compression force alone or combined with posterior shear, internal rotation torque, or varus moment was applied to the femurs of 5 fresh cadaveric knees. A Tekscan pressure mapping system was used to measure pressure and contact area between the femoral condyles, meniscus, and tibial plateau. A Microscribe 3D digitizer was used to define the 3-dimensional positions of the femur and tibia. A 10-mm and then a 20-mm osteotomy was created with a saw at an angle of 30 degrees in the axial plane with respect to the tangent of the posterior tibial plateau and 75 degrees in the sagittal plane, representing a typical posteromedial fracture fragment. At each flexion angle (15, 30, 60, 90, and 120 degrees) and loading condition (axial compression only, compression with shear force, torque, and varus moment), distal displacement of the medial femoral condyle and the tibial fracture fragments was determined. For the 10-mm fragment, medial femoral condyle displacement was little affected up to approximately 30-degree flexion, after which it increased. For the 20-mm fragment, there was progressive medial femoral condyle displacement with increasing flexion from baseline. However, for the 10- and 20-mm fragments themselves, displacements were noted at every flexion angle, starting at 1.7 mm inferior displacement with 15 degrees of flexion and internal rotation torque and up to 10.2 mm displacement with 90 degrees of flexion and varus bending moment. In this cadaveric model of a posteromedial tibial plateau fracture, both fracture fragments studied displaced with knee flexion, even at low flexion angles. Although such fragments may initially seem nondisplaced after injury, posteromedial fragments similar to these tested are likely to displace during knee range of motion exercises in non-weight-bearing conditions.

Lower limb strength in professional soccer players: profile, asymmetry, and training age.

PubMed

Fousekis, Konstantinos; Tsepis, Elias; Vagenas, George

2010-01-01

Kicking and cutting skills in soccer are clearly unilateral, require asymmetrical motor patterns and lead to the development of asymmetrical adaptations in the musculoskeletal function of the lower limbs. Assuming that these adaptations constitute a chronicity-dependent process, this study examined the effects of professional training age (PTA) on the composite strength profile of the knee and ankle joint in soccer players. One hundred soccer players (n=100) with short (5-7 years), intermediate (8-10 years) and long (>11 years) PTA were tested bilaterally for isokinetic concentric and eccentric strength of the knee and ankle muscles. Knee flexion-extension was tested concentrically at 60°, 180° and 300 °/sec and eccentrically at 60° and 180 °/sec. Ankle dorsal and plantar flexions were tested at 60 °/sec for both the concentric and eccentric mode of action. Bilaterally averaged muscle strength [(R+L)/2] increased significantly from short training age to intermediate and stabilized afterwards. These strength adaptations were mainly observed at the concentric function of knee extensors at 60°/sec (p = 0. 023), knee flexors at 60°/sec (p = 0.042) and 180°/sec (p = 0.036), and ankle plantar flexors at 60o/sec (p = 0.044). A linear trend of increase in isokinetic strength with PTA level was observed for the eccentric strength of knee flexors at 60°/sec (p = 0.02) and 180°/sec (p = 0.03). Directional (R/L) asymmetries decreased with PTA, with this being mainly expressed in the concentric function of knee flexors at 180°/sec (p = 0.04) and at 300 °/sec (p = 0.03). These findings confirm the hypothesis of asymmetry in the strength adaptations that take place at the knee and ankle joint of soccer players mainly along with short and intermediate PTA. Players with a longer PTA seem to adopt a more balanced use of their lower extremities to cope with previously developed musculoskeletal asymmetries and possibly reduce injury risk. This has certain implications regarding proper training and injury prevention in relation to professional experience in soccer. Key pointsMuscle strength increased from the low (5-7 years) to the intermediate professional training age (8-10 years) and stabilized thereafter.Soccer practicing and competition at the professional level induces critical strength adaptations (asymmetries) regarding the function of the knee and ankle musculature.Soccer players with long professional training age showed a tendency for lower isokinetic strength asymmetries than players with intermediate and short professional training age.

The influence of tennis court surfaces on player perceptions and biomechanical response.

PubMed

Starbuck, Chelsea; Damm, Loïc; Clarke, James; Carré, Matt; Capel-Davis, Jamie; Miller, Stuart; Stiles, Victoria; Dixon, Sharon

2016-09-01

This study aimed to examine player perceptions and biomechanical responses to tennis surfaces and to evaluate the influence of prior clay court experience. Two groups with different clay experiences (experience group, n = 5 and low-experience group, n = 5) performed a 180° turning movement. Three-dimensional ankle and knee movements (50 Hz), plantar pressure of the turning step (100 Hz) and perception data (visual analogue scale questionnaire) were collected for two tennis courts (acrylic and clay). Greater initial knee flexion (acrylic 20. 8 ± 11.2° and clay 32.5 ± 9.4°) and a more upright position were reported on the clay compared to the acrylic court (P < 0.05). This suggests adaptations to increase player stability on clay. Greater hallux pressures and lower midfoot pressures were observed on the clay court, allowing for sliding whilst providing grip at the forefoot. Players with prior clay court experience exhibited later peak knee flexion compared to those with low experience. All participants perceived the differences in surface properties between courts and thus responded appropriately to these differences. The level of previous clay court experience did not influence players' perceptions of the surfaces; however, those with greater clay court experience may reduce injury risk as a result of reduced loading through later peak knee flexion.

Effects of muscle activation on shear between human soleus and gastrocnemius muscles.

PubMed

Finni, T; Cronin, N J; Mayfield, D; Lichtwark, G A; Cresswell, A G

2017-01-01

Lateral connections between muscles provide pathways for myofascial force transmission. To elucidate whether these pathways have functional roles in vivo, we examined whether activation could alter the shear between the soleus (SOL) and lateral gastrocnemius (LG) muscles. We hypothesized that selective activation of LG would decrease the stretch-induced shear between LG and SOL. Eleven volunteers underwent a series of knee joint manipulations where plantar flexion force, LG, and SOL muscle fascicle lengths and relative displacement of aponeuroses between the muscles were obtained. Data during a passive full range of motion were recorded, followed by 20° knee extension stretches in both passive conditions and with selective electrical stimulation of LG. During active stretch, plantar flexion force was 22% greater (P < 0.05) and relative displacement of aponeuroses was smaller than during passive stretch (P < 0.05). Soleus fascicle length changes did not differ between passive and active stretches but LG fascicles stretched less in the active than passive condition when the stretch began at angles of 70° and 90° of knee flexion (P < 0.05). The activity-induced decrease in the relative displacement of SOL and LG suggests stronger (stiffer) connectivity between the two muscles, at least at flexed knee joint angles, which may serve to facilitate myofascial force transmission. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

In vivo kinematics of a robot-assisted uni- and multi-compartmental knee arthroplasty.

PubMed

Watanabe, Toshifumi; Abbasi, Ali Z; Conditt, Michael A; Christopher, Jennifer; Kreuzer, Stefan; Otto, Jason K; Banks, Scott A

2014-07-01

There is great interest in providing reliable and durable treatments for one- and two-compartment arthritic degeneration of the cruciate-ligament intact knee. One approach is to resurface only the diseased compartments with discrete unicompartmental components, retaining the undamaged compartment(s). However, placing multiple small implants into the knee presents a greater surgical challenge than total knee arthroplasty, so it is not certain that the natural knee mechanics can be maintained or restored. The goal of this study was to determine whether near-normal knee kinematics can be obtained with a robot-assisted multi-compartmental knee arthroplasty. Thirteen patients with 15 multi-compartmental knee arthroplasties using haptic robotic-assisted bone preparation were involved in this study. Nine subjects received a medial unicompartmental knee arthroplasty (UKA), three subjects received a medial UKA and patellofemoral (PF) arthroplasty, and three subjects received medial and lateral bi-unicondylar arthroplasty. Knee motions were recorded using video-fluoroscopy an average of 13 months (6-29 months) after surgery during stair and kneeling activities. The three-dimensional position and orientation of the implant components were determined using model-image registration techniques. Knee kinematics during maximum flexion kneeling showed femoral external rotation and posterior lateral condylar translation. All knees showed femoral external rotation and posterior condylar translation with flexion during the step activity. Knees with medial UKA and PF arthroplasty showed the most femoral external rotation and posterior translation, and knees with bicondylar UKA showed the least. Knees with accurately placed uni- or bi-compartmental arthroplasty exhibited stable knee kinematics consistent with intact and functioning cruciate ligaments. The patterns of tibiofemoral motion were more similar to natural knees than commonly has been observed in knees with total knee arthroplasty. Larger series are required to confirm these as general observations, but the present results demonstrate the potential to restore or maintain closer-to-normal knee kinematics by retaining intact structures and compartments.

An In Vitro Robotic Assessment of the Anterolateral Ligament, Part 1: Secondary Role of the Anterolateral Ligament in the Setting of an Anterior Cruciate Ligament Injury.

PubMed

Rasmussen, Matthew T; Nitri, Marco; Williams, Brady T; Moulton, Samuel G; Cruz, Raphael Serra; Dornan, Grant J; Goldsmith, Mary T; LaPrade, Robert F

2016-03-01

Recent investigations have described the structural and functional behavior of the anterolateral ligament (ALL) of the knee through pull-apart and isolated sectioning studies. However, the secondary stabilizing role of the ALL in the setting of a complete anterior cruciate ligament (ACL) tear has not been fully defined for common simulated clinical examinations, such as the pivot-shift, anterior drawer, and internal rotation tests. Combined sectioning of the ALL and ACL would lead to increased internal rotation and increased axial plane translation during a pivot-shift test when compared with isolated sectioning of the ACL. Controlled laboratory study. Ten fresh-frozen human cadaveric knees were subjected to a simulated pivot-shift test with coupled 10-N·m valgus and 5-N·m internal rotation torques from 0° to 60° of knee flexion and a 5-N·m internal rotation torque and an 88-N anterior tibial load, both from 0° to 120° of knee flexion via a 6 degrees of freedom robotic system. Kinematic changes were measured and compared with the intact state for isolated sectioning of the ACL and combined sectioning of the ACL and ALL. Combined sectioning of the ACL and ALL resulted in a significant increase in axial plane tibial translation during a simulated pivot shift at 0°, 15°, 30°, and 60° of knee flexion and a significant increase in internal rotation at 0°, 15°, 30°, 45°, 60°, 75°, 90°, 105°, and 120° when compared with the intact and ACL-deficient states. Based on the model results, ALL sectioning resulted in an additional 2.1 mm (95% CI, 1.4-2.9 mm; P < .001) of axial plane translation during the pivot shift when compared with ACL-only sectioning, when pooling evidence over all flexion angles. Likewise, when subjected to IR torque, the ACL+ALL-deficient state resulted in an additional 3.2° of internal rotation (95% CI, 2.4°-4.1°; P < .001) versus the intact state, and the additional sectioning of the ALL increased internal rotation by 2.7° (95% CI, 1.8°-3.6°; P < .001) versus the ACL-deficient state. The results of this study confirm the ALL as an important lateral knee structure that provides rotatory stability to the knee. Specifically, the ALL was a significant secondary stabilizer throughout flexion during an applied internal rotation torque and simulated pivot-shift test in the context of an ACL-deficient knee. Residual internal rotation and a positive pivot shift after ACL reconstruction may be attributed to ALL injury. For these patients, surgical treatment of an ALL tear may be considered. © 2015 The Author(s).

The effectiveness of Kinesio Taping® after total knee replacement in early postoperative rehabilitation period. A randomized controlled trial.

PubMed

Donec, V; Kriščiūnas, A

2014-08-01

The number of total knee replacements performed each year is increasing. Among the main impediments to functional recovery after these surgeries include postoperative edema, pain, lower limb muscle strength deficits, all of which point to a need to identify safe, effective postoperative rehabilitation modalities. The aim of this paper was to evaluate the effectiveness of Kinesio Taping® (KT) method in reducing postoperative pain, edema, and improved knee range of motion recovery after total knee replacement (TKR) operation in early postoperative rehabilitation period. Randomized clinical trial. Inpatient rehabilitation facility. Ninety-four patients, who underwent primary TKR surgery. Using simple randomization, participants were divided into KT group and control group. Both groups received same rehabilitation program and procedures after surgery, except KT group also received KT applications throughout all rehabilitation period. Postoperative pain, edema, restoration of the operated knee flexion and extension were evaluated. The chosen level of significance was P<0.05; in evaluation power of the test β ≤ 0.2. Groups were homogenous to sex, age, BMI, comorbidities, preoperative knee flexion/extension impairment, preoperative pain intensity, anaesthesia, prosthesis implanted (P>0.05). In both groups postoperative pain decreased significantly during rehabilitation period, however less pain was found in KT group from the second postoperative week till the end of inpatient rehabilitation (28th postoperative day) (P<0.05; β ≤ 0.2). Postoperative edema was less intense and subsided more quickly in KT group as well (P<0.05; β ≤ 0.2). No difference was found in improvement of knee flexion (P>0.05). Operated knee extension was found better in KT group then in control at the end of in-patient rehabilitation (P<0.05; β ≤ 0.2). KT was well tolerated by patients. KT technique appeared to be beneficial for reducing postoperative pain, edema, improving knee extension in early postoperative rehabilitation period. This finding implies for health care professionals working in the field of physical medicine and rehabilitation that Kinesio Taping® method is safe and can be used as additional rehabilitation means for patients after TKR.

Definition and evaluation of testing scenarios for knee wear simulation under conditions of highly demanding daily activities.

PubMed

Schwiesau, Jens; Schilling, Carolin; Kaddick, Christian; Utzschneider, Sandra; Jansson, Volkmar; Fritz, Bernhard; Blömer, Wilhelm; Grupp, Thomas M

2013-05-01

The objective of our study was the definition of testing scenarios for knee wear simulation under various highly demanding daily activities of patients after total knee arthroplasty. This was mainly based on a review of published data on knee kinematics and kinetics followed by the evaluation of the accuracy and precision of a new experimental setup. We combined tibio-femoral load and kinematic data reported in the literature to develop deep squatting loading profiles for simulator input. A servo-hydraulic knee wear simulator was customised with a capability of a maximum flexion of 120°, a tibio-femoral load of 5000N, an anterior-posterior (AP) shear force of ±1000N and an internal-external (IE) rotational torque of ±50Nm to simulate highly demanding patient activities. During the evaluation of the newly configurated simulator the ability of the test machine to apply the required load and torque profiles and the flexion kinematics in a precise manner was examined by nominal-actual profile comparisons monitored periodically during subsequent knee wear simulation. For the flexion kinematics under displacement control a delayed actuator response of approximately 0.05s was inevitable due to the inertia of masses in movement of the coupled knee wear stations 1-3 during all applied activities. The axial load and IE torque is applied in an effective manner without substantial deviations between nominal and actual load and torque profiles. During the first third of the motion cycle a marked deviation between nominal and actual AP shear load profiles has to be noticed but without any expected measurable effect on the latter wear simulation due to the fact that the load values are well within the peak magnitude of the nominal load amplitude. In conclusion the described testing method will be an important tool to have more realistic knee wear simulations based on load conditions of the knee joint during activities of daily living. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

Posteromedial knee friction syndrome: an entity with medial knee pain and edema between the femoral condyle, sartorius and gracilis.

PubMed

Simeone, F Joseph; Huang, Ambrose J; Chang, Connie Y; Smith, Maximilian; Gill, Thomas J; Bredella, Miriam A; Torriani, Martin

2015-04-01

To describe MRI features of an entity consisting of medial knee pain and edema between the posteromedial femoral condyle (PMFC), sartorius and/or gracilis tendons and determine whether reduced tendon-bone distances may account for these findings. We retrospectively identified MRI cases of edema between the PMFC, sartorius and/or gracilis tendons (25 subjects, 26 knees). Two musculoskeletal radiologists independently graded edema and measured the sartorius- and gracilis-PMFC distances and knee flexion angle. Age- and gender-matched subjects with normal knee MRIs (27 subjects, 27 knees) served as controls for measurements. Statistical analyses compared abnormal to control subjects. Sartorius-PMFC and gracilis-PMFC spaces were narrower in abnormal compared to control subjects (1.6 ± 1.0 vs. 2.1 ± 1.2 mm, P = 0.04; 2.3 ± 2.0 vs. 4.6 ± 3.0 mm, P = 0.002, respectively). The knee flexion angle was similar between groups (P > 0.05). In subjects with clinical information, medial knee pain was the main complaint in 58 % (15/26) of abnormal subjects, with 42 % (11/26) having clinical suspicion of medial meniscal tear. Edema between the PMFC, sartorius and/or gracilis was mild in 54 % (14/26), moderate in 35 % (9/26) and severe in 12 % (3/26), and it was most frequent deep to both the sartorius and gracilis (50 %, 13/26). Edema between the PMFC, sartorius and/or gracilis tendons identified on knee MRI may be associated with medial knee pain and may represent a friction syndrome.

The Position of the Patella and Extensor Mechanism Affects Intraoperative Compartmental Loads During Total Knee Arthroplasty: A Pilot Study Using Intraoperative Sensing to Guide Soft Tissue Balance.

PubMed

Schnaser, Erik; Lee, Yuo-yu; Boettner, Friedrich; Gonzalez Della Valle, Alejandro

2015-08-01

The achievement of a well-balanced total knee arthroplasty is necessary for long-term success. We hypothesize that the dislocation of the patella during surgery affects the distribution of loads in the medial and lateral compartments. Intraoperative load sensors were used to record medial and lateral compartment loads in 56 well-balanced TKAs. Loads were recorded in full extension, relaxed extension, at 45 and 90° of flexion at full gravity-assisted flexion, with the patella in four different positions: dislocated (everted and not), located, and located and secured with two retinacular sutures. The loads in the lateral compartment in flexion were higher with a dislocated patella than with a located patella (P<0.001). A lateralized extensor mechanism artificially increases in the lateral compartment loads in flexion during TKA surgery. Instruments that allow intraoperative soft tissue balance with the patella in a physiologic position are more likely to replicate postoperative compartment loads. II (prospective comparative study). Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Slack length of gastrocnemius medialis and Achilles tendon occurs at different ankle angles.

PubMed

Hug, François; Lacourpaille, Lilian; Maïsetti, Olivier; Nordez, Antoine

2013-09-27

Although muscle-tendon slack length is a crucial parameter used in muscle models, this is one of the most difficult measures to estimate in vivo. The aim of this study was to determine the onset of the rise in tension (i.e., slack length) during passive stretching in both Achilles tendon and gastrocnemius medialis. Muscle and tendon shear elastic modulus was measured by elastography (supersonic shear imaging) during passive plantarflexion (0° and 90° of knee angle, 0° representing knee fully extended, in a random order) in 9 participants. The within-session repeatability of the determined slack length was good at 90° of knee flexion (SEM=3.3° and 2.2° for Achilles tendon and gastrocnemius medialis, respectively) and very good at 0° of knee flexion (SEM=1.9° and 1.9° for Achilles tendon and gastrocnemius medialis, respectively). The slack length of gastrocnemius medialis was obtained at a significantly lower plantarflexed angle than for Achilles tendon at both 0° (P<0.0001; mean difference=19.4±3.8°) and 90° of knee flexion (P<0.0001; mean difference=25.5±7.6°). In conclusion, this study showed that the joint angle at which the tendon falls slack can be experimentally determined using supersonic shear imaging. The slack length of gastrocnemius medialis and Achilles tendon occurred at different joint angles. Although reporting this result is crucial to a better understanding of muscle-tendon interactions, further experimental investigations are required to explain this result. Copyright © 2013 Elsevier Ltd. All rights reserved.

The influence of sex and obesity on gait biomechanics in people with severe knee osteoarthritis scheduled for arthroplasty.

PubMed

Paterson, K L; Sosdian, L; Hinman, R S; Wrigley, T V; Kasza, J; Dowsey, M; Choong, P; Bennell, K L

2017-11-01

Sex and body mass may influence knee biomechanics associated with poor total knee arthroplasty (TKA) outcomes for knee osteoarthritis (OA). This study aimed to determine if gait differed between men and women, and overweight and class I obese patients with severe knee OA awaiting TKA. 34 patients with severe knee OA (average age 70.0 (SD 7.2) years, body mass index 30.3 (4.1kg/m 2 )) were recruited from a TKA waiting list. Three-dimensional gait analysis was performed at self-selected walking speed. Comparisons were made between men and women, and overweight (body mass index (BMI) 25.0-29.9kg/m 2 ) and class I obese (BMI 30.0-34.9kg/m 2 ) participants. Biomechanical outcomes included absolute and body size-adjusted peak knee adduction moment (KAM), KAM impulse, peak knee flexion moment, as well as peak knee flexion and varus-valgus angles, peak varus-valgus thrust, and peak vertical ground reaction force (GRF). Men had a higher absolute peak KAM, KAM impulse and peak GRF compared to women, and this sex-difference in frontal plane moments remained after adjusting for body size. However, when additionally adjusting for static knee alignment, differences disappeared. Knee biomechanics were similar between obesity groups after adjusting for the greater body weight of those with class I obesity. Men had greater KAM and KAM impulse even after adjustment for body size; however adjustment for their more varus knees removed this difference. Obesity group did not influence knee joint kinematics or moments. This suggests sex- and obesity-differences in these variables may not be associated with TKA outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of Juvenile Idiopathic Arthritis on Kinematics and Kinetics of the Lower Extremities Call for Consequences in Physical Activities Recommendations

PubMed Central

Hartmann, M.; Kreuzpointner, F.; Haefner, R.; Michels, H.; Schwirtz, A.; Haas, J. P.

2010-01-01

Juvenile idiopathic arthritis (JIA) patients (n = 36) with symmetrical polyarticular joint involvement of the lower extremities and healthy controls (n = 20) were compared concerning differences in kinematic, kinetic, and spatio-temporal parameters with 3D gait analysis. The aims of this study were to quantify the differences in gait between JIA patients and healthy controls and to provide data for more detailed sport activities recommendations. JIA-patients showed reduced walking speed and step length, strongly anterior tilted pelvis, reduced maximum hip extension, reduced knee extension during single support phase and reduced plantar flexion in push off. Additionally the roll-off procedure of the foot was slightly decelerated. The reduced push off motion in the ankle was confirmed by lower peaks in ankle moment and power. The gait of JIA-patients can be explained as a crouch-like gait with hyperflexion in hip and knee joints and less plantar flexion in the ankle. A preventive mobility workout would be recommendable to reduce these restrictions in the future. Advisable are sports with emphasis on extension in hip, knee, and ankle plantar flexion. PMID:20862334

Posterior cruciate-retaining versus posterior-stabilized total knee arthroplasty for osteoarthritis with severe varus deformity.

PubMed

Ünkar, Ethem Ayhan; Öztürkmen, Yusuf; Şükür, Erhan; Çarkçı, Engin; Mert, Murat

2017-03-01

The aim of this study was to compare the radiological and functional results of posterior cruciate ligament (PCL) - retaining and posterior-stabilized total knee arthroplasties in patients with severe varus gonarthrosis. Medical records of 112 knees of 96 patients who underwent total knee arthroplasty for severe varus (≥15°) were reviewed. PCL-retaining and PCL-stabilizing groups consisted of 58 and 54 knees, respectively. Mean follow-up time was 56.6 months (range: 24-112 months). Knee Society (KS) clinical rating system was used in clinical evaluation. Range of motion, degree of flexion contracture, postoperative alignment, and complication rates were compared between the groups. Mean preoperative mechanical tibiofemoral angle was 20.1° in varus alignment, and was restored to 4.6° in valgus postoperatively. No statistically significant differences were found between PCL-stabilizing and PCL-retaining groups when KS knee scores, function scores, and flexion arc were evaluated. Two patients in PCL-retaining group underwent revision surgery due to aseptic loosening of tibial component. One patient in PCL-stabilizing group needed arthrotomy due to patellar clunk syndrome. There were no notable differences between the 2 groups and PCL-retaining design had outcomes as good as PCL-stabilizing total knee implant in osteoarthritic knees with severe varus deformity. Level III, Therapeutic study. Copyright © 2016 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.