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Sample records for normal ankle joint

  1. Biomechanics of the normal and arthritic ankle joint.

    PubMed

    Snedeker, Jess G; Wirth, Stephan H; Espinosa, Norman

    2012-12-01

    Understanding biomechanics of the normal and arthritic ankle joint can aid in analysis of an underlying clinical problem and provide a strategic basis for a more optimal management. The challenge to the clinician and the biomechanist is that the mechanical complexity of the ankle joint still clouds current understanding. This article provides an overview of current understanding of functional ankle anatomy, how this function can be altered in the degenerated ankle, and how surgical intervention further affects foot and ankle biomechanics. The focus is on how altered loading of neighboring joints in the midfoot and hindfoot may induce postoperative joint remodeling and can manifest in secondary clinical problems.

  2. Total ankle joint replacement.

    PubMed

    2016-02-01

    Ankle arthritis results in a stiff and painful ankle and can be a major cause of disability. For people with end-stage ankle arthritis, arthrodesis (ankle fusion) is effective at reducing pain in the shorter term, but results in a fixed joint, and over time the loss of mobility places stress on other joints in the foot that may lead to arthritis, pain and dysfunction. Another option is to perform a total ankle joint replacement, with the aim of giving the patient a mobile and pain-free ankle. In this article we review the efficacy of this procedure, including how it compares to ankle arthrodesis, and consider the indications and complications.

  3. The Effect of Cryotherapy on the Normal Ankle Joint Position Sense

    PubMed Central

    khanmohammadi, Roya; Someh, Marjan; Ghafarinejad, Farahnaze

    2011-01-01

    Purpose To determine whether a fifteen-minute water immersion treatment affects the normal ankle joint position sense (JPS) at the middle range of dorsiflexion and plantar flexion actively and passively. Methods Thirty healthy female volunteers aged between 18 and 30 years were treated by a 15-minute cryotherapy (6 ± 1°C). The subject's skin temperature over antromedial aspect of dominant ankle was measured by the Mayomed device before, immediate and 15 minutes after water immersion. Ankle JPS was tested trough the pedal goniometer at 3 stages similar to the skin temperature. ANOVA (α = 0.05) was performed on each of variables using SPSS 19.0 software. Results Skin temperature was seen to decrease after water immersion but subjects did not return to pre-test skin temperature after 15 minutes (P<0.001). The research found no significant difference in JPS at middle range of dorsiflexion and plantar flexion actively and passively before and after cryotherapy. Conclusion These findings suggest that 15-minute water immersion at 6°C dose not significantly alter the middle range of plantar flexion/ dorsiflexion JPS at the ankle and is not deleterious to JPS. PMID:22375224

  4. [Biomechanics of the ankle joint].

    PubMed

    Zwipp, H

    1989-03-01

    According to Fick, the tree-dimensional patterns of foot motion are best characterized as jawlike movement. Anatomically and biomechanically, this process represents conjoined, synchronous motion within the three mobile segments of the hindfoot: the ankle joint, the posterior subtalar joint, and the anterior subtalar joint. Foot kinematics can be described more completely if the anterior subtalar joint is defined not only as the talocalcaneal navicular joint, but as including the calcaneocuboid joint, thus representing the transverse joint of the tarsus, i.e., the Chopart joint. The axes of these three joints can be defined precisely. In some parts they represent a screwlike motion, clockwise or counter-clockwise, around the central ligamentous structures (fibulotibial ligament, talocalcaneal interosseous ligament, bifurcate ligament). The individual anatomy and structure of these ligaments provide variations in the degree and direction of foot motion. A precise knowledge of foot kinematics is important in surgical ligament and joint reconstruction and in selective foot arthrodeses.

  5. The Foot and Ankle: An Overview of Arthrokinematics and Selected Joint Techniques

    PubMed Central

    Loudon, Janice K.; Bell, Stephania L.

    1996-01-01

    Limited range of motion of the ankle is common following a period of immobilization or injury to the lower extremity. If not corrected, this limited range of motion will disturb normal joint arthrokinematics and could affect the athlete's performance. Consequently, the athletic trainer must thoroughly evaluate the various joints of the ankle and foot in order to determine appropriate treatment. A comprehensive evaluation should include assessment of passive accessory motions at the foot and ankle. If accessory movements are restricted at any joint, mobilization techniques can be used to restore normal ankle/foot joint arthrokinematics. This article describes the biomechanics of the tibiofibular, talocrural, subtalar, and midtarsal joints and is a presentation of basic mobilization techniques for the ankle and related joints. ImagesFig 3.Fig 4.Fig 5.Fig 6.Fig 7.Fig 8.Fig 9.Fig 10.Fig 11.Fig 12.Fig 13. PMID:16558394

  6. Factors Contributing to Chronic Ankle Instability: Kinesthesia and Joint Position Sense

    PubMed Central

    Konradsen, Lars

    2002-01-01

    Objective: To present a comprehensive review of the influence of altered kinesthesia and joint position sense on chronic ankle instability and to present a model connecting deficits in ankle position sense with the increased risk of sustaining lateral ankle sprains. Data Sources: I searched MEDLINE for the years 1966–2001 using the key words ankle and kinesthesia or position sense and books on proprioception. Data Synthesis: Study findings suggest a risk for unprovoked lateral ankle sprains when the lateral border of the foot accidentally catches the ground surface during the late swing phase of normal locomotion. In normal situations, the lateral border of the foot clears the ground by only 5 mm, and a small increase in ankle-position error may substantially increase the risk of a collision. Findings of affected kinesthesia and joint position sense in subjects with chronically unstable ankles dominate over studies showing nonsignificant results, but the answer is far from clear. Conclusions/Recommendations: Changes in joint position sense and kinesthesia of a magnitude found in subjects with chronically unstable ankles can lead to an increased risk of sustaining lateral ankle sprains. Results from a small number of studies suggest that balance and coordination training can restore the increased uncertainty of joint positioning to normal levels. PMID:12937559

  7. Ankle and hip postural strategies defined by joint torques.

    PubMed

    Runge, C F; Shupert, C L; Horak, F B; Zajac, F E

    1999-10-01

    Previous studies have identified two discrete strategies for the control of posture in the sagittal plane based on EMG activations, body kinematics, and ground reaction forces. The ankle strategy was characterized by body sway resembling a single-segment-inverted pendulum and was elicited on flat support surfaces. In contrast, the hip strategy was characterized by body sway resembling a double-segment inverted pendulum divided at the hip and was elicited on short or compliant support surfaces. However, biomechanical optimization models have suggested that hip strategy should be observed in response to fast translations on a flat surface also, provided the feet are constrained to remain in contact with the floor and the knee is constrained to remain straight. The purpose of this study was to examine the experimental evidence for hip strategy in postural responses to backward translations of a flat support surface and to determine whether analyses of joint torques would provide evidence for two separate postural strategies. Normal subjects standing on a flat support surface were translated backward with a range of velocities from fast (55 cm/s) to slow (5 cm/s). EMG activations and joint kinematics showed pattern changes consistent with previous experimental descriptions of mixed hip and ankle strategy with increasing platform velocity. Joint torque analyses revealed the addition of a hip flexor torque to the ankle plantarflexor torque during fast translations. This finding indicates the addition of hip strategy to ankle strategy to produce a continuum of postural responses. Hip torque without accompanying ankle torque (pure hip strategy) was not observed. Although postural control strategies have previously been defined by how the body moves, we conclude that joint torques, which indicate how body movements are produced, are useful in defining postural control strategies. These results also illustrate how the biomechanics of the body can transform discrete control

  8. Ankle and hip postural strategies defined by joint torques

    NASA Technical Reports Server (NTRS)

    Runge, C. F.; Shupert, C. L.; Horak, F. B.; Zajac, F. E.; Peterson, B. W. (Principal Investigator)

    1999-01-01

    Previous studies have identified two discrete strategies for the control of posture in the sagittal plane based on EMG activations, body kinematics, and ground reaction forces. The ankle strategy was characterized by body sway resembling a single-segment-inverted pendulum and was elicited on flat support surfaces. In contrast, the hip strategy was characterized by body sway resembling a double-segment inverted pendulum divided at the hip and was elicited on short or compliant support surfaces. However, biomechanical optimization models have suggested that hip strategy should be observed in response to fast translations on a flat surface also, provided the feet are constrained to remain in contact with the floor and the knee is constrained to remain straight. The purpose of this study was to examine the experimental evidence for hip strategy in postural responses to backward translations of a flat support surface and to determine whether analyses of joint torques would provide evidence for two separate postural strategies. Normal subjects standing on a flat support surface were translated backward with a range of velocities from fast (55 cm/s) to slow (5 cm/s). EMG activations and joint kinematics showed pattern changes consistent with previous experimental descriptions of mixed hip and ankle strategy with increasing platform velocity. Joint torque analyses revealed the addition of a hip flexor torque to the ankle plantarflexor torque during fast translations. This finding indicates the addition of hip strategy to ankle strategy to produce a continuum of postural responses. Hip torque without accompanying ankle torque (pure hip strategy) was not observed. Although postural control strategies have previously been defined by how the body moves, we conclude that joint torques, which indicate how body movements are produced, are useful in defining postural control strategies. These results also illustrate how the biomechanics of the body can transform discrete control

  9. Bone alterations are associated with ankle osteoarthritis joint pain

    PubMed Central

    Nakamura, Yukio; Uchiyama, Shigeharu; Kamimura, Mikio; Komatsu, Masatoshi; Ikegami, Shota; Kato, Hiroyuki

    2016-01-01

    The etiology of ankle osteoarthritis (OA) is largely unknown. We analyzed 24 ankle OA of 21 patients diagnosed by plain radiographs using magnetic resonance imaging (MRI). Ankle joint pain disappeared in 22 out of 24 joints by conservative treatment. MRI bone signal changes in and around the ankle joints were observed in 22 of 24 joints. Bone signal changes along the joint line were seen in 10 of 11 joints as a Kellgren-Lawrence (KL) grade of II to IV. Such signal changes were witnessed in only 4 of 13 joints with KL grade 0 or I. In the talocrural joint, bone alterations occurred in both tibia and talus bones through the joint line in cases of KL grade III or IV, while focal bone alterations were present in the talus only in KL grade I or II cases. Sixteen of 24 joints exhibited intraosseous bone signal changes, which tended to correspond to joint pain of any ankle OA stage. Our results suggest that bone alterations around the ankle joint might be one of the etiologies of OA and associated with ankle joint pain. PMID:26776564

  10. Bone alterations are associated with ankle osteoarthritis joint pain.

    PubMed

    Nakamura, Yukio; Uchiyama, Shigeharu; Kamimura, Mikio; Komatsu, Masatoshi; Ikegami, Shota; Kato, Hiroyuki

    2016-01-18

    The etiology of ankle osteoarthritis (OA) is largely unknown. We analyzed 24 ankle OA of 21 patients diagnosed by plain radiographs using magnetic resonance imaging (MRI). Ankle joint pain disappeared in 22 out of 24 joints by conservative treatment. MRI bone signal changes in and around the ankle joints were observed in 22 of 24 joints. Bone signal changes along the joint line were seen in 10 of 11 joints as a Kellgren-Lawrence (KL) grade of II to IV. Such signal changes were witnessed in only 4 of 13 joints with KL grade 0 or I. In the talocrural joint, bone alterations occurred in both tibia and talus bones through the joint line in cases of KL grade III or IV, while focal bone alterations were present in the talus only in KL grade I or II cases. Sixteen of 24 joints exhibited intraosseous bone signal changes, which tended to correspond to joint pain of any ankle OA stage. Our results suggest that bone alterations around the ankle joint might be one of the etiologies of OA and associated with ankle joint pain.

  11. Compensatory strategies during walking in response to excessive muscle co-contraction at the ankle joint.

    PubMed

    Wang, Ruoli; Gutierrez-Farewik, Elena M

    2014-03-01

    Excessive co-contraction causes inefficient or abnormal movement in several neuromuscular pathologies. How synergistic muscles spanning the ankle, knee and hip adapt to co-contraction of ankle muscles is not well understood. This study aimed to identify the compensation strategies required to retain normal walking with excessive antagonistic ankle muscle co-contraction. Muscle-actuated simulations of normal walking were performed to quantify compensatory mechanisms of ankle and knee muscles during stance in the presence of normal, medium and high levels of co-contraction of antagonistic pairs gastrocnemius+tibialis anterior and soleus+tibialis anterior. The study showed that if co-contraction increases, the synergistic ankle muscles can compensate; with gastrocmemius+tibialis anterior co-contraction, the soleus will increase its contribution to ankle plantarflexion acceleration. At the knee, however, almost all muscles spanning the knee and hip are involved in compensation. We also found that ankle and knee muscles alone can provide sufficient compensation at the ankle joint, but hip muscles must be involved to generate sufficient knee moment. Our findings imply that subjects with a rather high level of dorsiflexor+plantarflexor co-contraction can still perform normal walking. This also suggests that capacity of other lower limb muscles to compensate is important to retain normal walking in co-contracted persons. The compensatory mechanisms can be useful in clinical interpretation of motion analyses, when secondary muscle co-contraction or other deficits may present simultaneously in subjects with motion disorders.

  12. 21 CFR 888.3100 - Ankle joint metal/composite semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ankle joint metal/composite semi-constrained... Ankle joint metal/composite semi-constrained cemented prosthesis. (a) Identification. An ankle joint... ankle joint. The device limits translation and rotation: in one or more planes via the geometry of...

  13. 21 CFR 888.3100 - Ankle joint metal/composite semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ankle joint metal/composite semi-constrained... Ankle joint metal/composite semi-constrained cemented prosthesis. (a) Identification. An ankle joint... ankle joint. The device limits translation and rotation: in one or more planes via the geometry of...

  14. Arthroscopic Anatomy of the Ankle Joint.

    PubMed

    Ray, Ronald G

    2016-10-01

    There are a number of variations in the intra-articular anatomy of the ankle which should not be considered pathological under all circumstances. The anteromedial corner of the tibial plafond (between the anterior edge of the tibial plafond and the medial malleolus) can have a notch, void of cartilage and bone. This area can appear degenerative arthroscopically; it is actually a normal variant of the articular surface. The anterior inferior tibiofibular ligament (AITF) can possess a lower, accessory band which can impinge on the anterolateral edge of the talar dome. In some cases it can cause irritation along this area of the talus laterally. If it is creating local irritation it can be removed since it does not provide any additional stabilization to the syndesmosis. There is a beveled region at the anterior leading edge of the lateral and dorsal surfaces of the talus laterally. This triangular region is void of cartilage and subchondral bone. The lack of talar structure in this region allows the lower portion of the AITF ligament to move over the talus during end range dorsiflexion of the ankle, preventing impingement. The variation in talar anatomy for this area should not be considered pathological. PMID:27599433

  15. Dynamic high-resolution US of ankle and midfoot ligaments: normal anatomic structure and imaging technique.

    PubMed

    Sconfienza, Luca Maria; Orlandi, Davide; Lacelli, Francesca; Serafini, Giovanni; Silvestri, Enzo

    2015-01-01

    The ankle is the most frequently injured major joint in the body, and ankle sprains are frequently encountered in individuals playing football, basketball, and other team sports, in addition to occurring in the general population. Imaging plays a crucial role in the evaluation of ankle ligaments. Magnetic resonance imaging has been proven to provide excellent evaluation of ligaments around the ankle, with the ability to show associated intraarticular abnormalities, joint effusion, and bone marrow edema. Ultrasonography (US) performed with high-resolution broadband linear-array probes has become increasingly important in the assessment of ligaments around the ankle because it is low cost, fast, readily available, and free of ionizing radiation. US can provide a detailed depiction of normal anatomic structures and is effective for evaluating ligament integrity. In addition, US allows the performance of dynamic maneuvers, which may contribute to increased visibility of normal ligaments and improved detection of tears. In this article, the authors describe the US techniques for evaluation of the ankle and midfoot ligaments and include a brief review of the literature related to their basic anatomic structures and US of these structures. Short video clips showing dynamic maneuvers and dynamic real-time US of ankle and midfoot structures and their principal pathologic patterns are included as supplemental material. Use of a standardized imaging technique may help reduce the intrinsic operator dependence of US. Online supplemental material is available for this article.

  16. Ankle pain

    MedlinePlus

    Pain - ankle ... Ankle pain is often due to an ankle sprain. An ankle sprain is an injury to the ligaments, which ... the joint. In addition to ankle sprains, ankle pain can be caused by: Damage or swelling of ...

  17. Ankle replacement

    MedlinePlus

    Ankle arthroplasty - total; Total ankle arthroplasty; Endoprosthetic ankle replacement; Ankle surgery ... You may not be able to have a total ankle replacement if you have had ankle joint infections ...

  18. Design of a simple, lightweight, passive-elastic ankle exoskeleton supporting ankle joint stiffness.

    PubMed

    Kim, Seyoung; Son, Youngsu; Choi, Sangkyu; Ham, Sangyong; Park, Cheolhoon

    2015-09-01

    In this study, a passive-elastic ankle exoskeleton (PEAX) with a one-way clutch mechanism was developed and then pilot-tested with vertical jumping to determine whether the PEAX is sufficiently lightweight and comfortable to be used in further biomechanical studies. The PEAX was designed to supplement the function of the Achilles tendon and ligaments as they passively support the ankle torque with their inherent stiffness. The main frame of the PEAX consists of upper and lower parts connected to each other by tension springs (N = 3) and lubricated hinge joints. The upper part has an offset angle of 5° with respect to the vertical line when the springs are in their resting state. Each spring has a slack length of 8 cm and connects the upper part to the tailrod of the lower part in the neutral position. The tailrod freely rotates with low friction but has a limited range of motion due to the stop pin working as a one-way clutch. Because of the one-way clutch system, the tension springs store the elastic energy only due to an ankle dorsiflexion when triggered by the stop pin. This clutch mechanism also has the advantage of preventing any inconvenience during ankle plantarflexion because it does not limit the ankle joint motion during the plantarflexion phase. In pilot jumping tests, all of the subjects reported that the PEAX was comfortable for jumping due to its lightweight (approximately 1 kg) and compact (firmly integrated with shoes) design, and subjects were able to nearly reach their maximum vertical jump heights while wearing the PEAX. During the countermovement jump, elastic energy was stored during dorsiflexion by spring extension and released during plantarflexion by spring restoration, indicating that the passive spring torque (i.e., supportive torque) generated by the ankle exoskeleton partially supported the ankle joint torque throughout the process.

  19. Design of a simple, lightweight, passive-elastic ankle exoskeleton supporting ankle joint stiffness

    NASA Astrophysics Data System (ADS)

    Kim, Seyoung; Son, Youngsu; Choi, Sangkyu; Ham, Sangyong; Park, Cheolhoon

    2015-09-01

    In this study, a passive-elastic ankle exoskeleton (PEAX) with a one-way clutch mechanism was developed and then pilot-tested with vertical jumping to determine whether the PEAX is sufficiently lightweight and comfortable to be used in further biomechanical studies. The PEAX was designed to supplement the function of the Achilles tendon and ligaments as they passively support the ankle torque with their inherent stiffness. The main frame of the PEAX consists of upper and lower parts connected to each other by tension springs (N = 3) and lubricated hinge joints. The upper part has an offset angle of 5° with respect to the vertical line when the springs are in their resting state. Each spring has a slack length of 8 cm and connects the upper part to the tailrod of the lower part in the neutral position. The tailrod freely rotates with low friction but has a limited range of motion due to the stop pin working as a one-way clutch. Because of the one-way clutch system, the tension springs store the elastic energy only due to an ankle dorsiflexion when triggered by the stop pin. This clutch mechanism also has the advantage of preventing any inconvenience during ankle plantarflexion because it does not limit the ankle joint motion during the plantarflexion phase. In pilot jumping tests, all of the subjects reported that the PEAX was comfortable for jumping due to its lightweight (approximately 1 kg) and compact (firmly integrated with shoes) design, and subjects were able to nearly reach their maximum vertical jump heights while wearing the PEAX. During the countermovement jump, elastic energy was stored during dorsiflexion by spring extension and released during plantarflexion by spring restoration, indicating that the passive spring torque (i.e., supportive torque) generated by the ankle exoskeleton partially supported the ankle joint torque throughout the process.

  20. Reliability of metatarsophalangeal and ankle joint torque measurements by an innovative device.

    PubMed

    Man, Hok-Sum; Leung, Aaron Kam-Lun; Cheung, Jason Tak-Man; Sterzing, Thorsten

    2016-07-01

    The toe flexor muscles maintain body balance during standing and provide push-off force during walking, running, and jumping. Additionally, they are important contributing structures to maintain normal foot function. Thus, weakness of these muscles may cause poor balance, inefficient locomotion and foot deformities. The quantification of metatarsophalangeal joint (MPJ) stiffness is valuable as it is considered as a confounding factor in toe flexor muscles function. MPJ and ankle joint stiffness measurement is still largely depended on manual skills as current devices do not have good control on alignment, angular joint speed and displacement during measurement. Therefore, this study introduces an innovative dynamometer and protocol procedures for MPJ and ankle Joint torque measurement with precise and reliable foot alignment, angular joint speed and displacement control. Within-day and between-day test-retest experiments on MPJ and ankle joint torque measurement were conducted on ten and nine healthy male subjects respectively. The mean peak torques of MPJ and ankle joint of between-day and within-day measurement were 1.50±0.38Nm/deg and 1.19±0.34Nm/deg. The corresponding torques of the ankle joint were 8.24±2.20Nm/deg and 7.90±3.18Nm/deg respectively. Intraclass-correlation coefficients (ICC) of averaged peak torque of both joints of between-day and within-day test-retest experiments were ranging from 0.91 to 0.96, indicating the innovative device is systematic and reliable for the measurements and can be used for multiple scientific and clinical purposes.

  1. Prestress revealed by passive co-tension at the ankle joint.

    PubMed

    Souza, Thales R; Fonseca, Sérgio T; Gonçalves, Gabriela G; Ocarino, Juliana M; Mancini, Marisa C

    2009-10-16

    This study was designed to test the assumption that elastic tissues of the ankle are prestressed, by investigating the presence of simultaneous opposite passive elastic moments and thus, passive co-tension, at the ankle joint. A prestressed two-spring model used to generate qualitative predictions of the effects of stretching the posterior elastic structures of the ankle on the net passive moment of this joint was used. Twenty-seven healthy individuals were subjected to passive evaluation of the net elastic moment of the ankle in the sagittal plane, with the knee positioned at 90 degrees, 60 degrees, 30 degrees and 0 degrees of flexion, in order to change the length of the posterior biarticular elastic structures. The placement of the knee in the more extended positions caused changes in the net passive moment as predicted by the prestressed model. The ankle position in which the net passive moment was equal to zero was shifted to more plantar flexed positions (p<0.001) and there was a global increase in ankle stiffness since both passive dorsiflexion stiffness (p< or =0.037) and passive plantar flexion stiffness (p< or =0.029) increased. The normalized terminal plantar flexion stiffness also increased (p< or =0.047), suggesting that biarticular posterior elastic structures are pre-strained and still under tension when the ankle is maximally plantar flexed and the knee is positioned at 60 degrees of flexion. Resting positions were indicative of equilibrium between opposite passive elastic moments. The results revealed that there is passive co-tension at the ankle, demonstrating the existence of prestress in elastic structures of this joint.

  2. 21 CFR 888.3110 - Ankle joint metal/polymer semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ankle joint metal/polymer semi-constrained... Ankle joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an...

  3. 21 CFR 888.3110 - Ankle joint metal/polymer semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ankle joint metal/polymer semi-constrained... Ankle joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an...

  4. 21 CFR 888.3110 - Ankle joint metal/polymer semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ankle joint metal/polymer semi-constrained... Ankle joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an...

  5. 21 CFR 888.3120 - Ankle joint metal/polymer non-constrained cemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ankle joint metal/polymer non-constrained cemented... metal/polymer non-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer non... December 26, 1996 for any ankle joint metal/polymer non-constrained cemented prosthesis that was...

  6. 21 CFR 888.3120 - Ankle joint metal/polymer non-constrained cemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ankle joint metal/polymer non-constrained cemented... metal/polymer non-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer non... December 26, 1996 for any ankle joint metal/polymer non-constrained cemented prosthesis that was...

  7. 21 CFR 888.3120 - Ankle joint metal/polymer non-constrained cemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ankle joint metal/polymer non-constrained cemented... metal/polymer non-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer non... December 26, 1996 for any ankle joint metal/polymer non-constrained cemented prosthesis that was...

  8. 21 CFR 888.3100 - Ankle joint metal/composite semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ankle joint metal/composite semi-constrained... Ankle joint metal/composite semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/composite semi-constrained cemented prosthesis is a device intended to be implanted to replace...

  9. 21 CFR 888.3100 - Ankle joint metal/composite semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ankle joint metal/composite semi-constrained... Ankle joint metal/composite semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/composite semi-constrained cemented prosthesis is a device intended to be implanted to replace...

  10. 21 CFR 888.3100 - Ankle joint metal/composite semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ankle joint metal/composite semi-constrained... Ankle joint metal/composite semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/composite semi-constrained cemented prosthesis is a device intended to be implanted to replace...

  11. 21 CFR 888.3110 - Ankle joint metal/polymer semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ankle joint metal/polymer semi-constrained... Ankle joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an...

  12. 21 CFR 888.3120 - Ankle joint metal/polymer non-constrained cemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ankle joint metal/polymer non-constrained cemented... metal/polymer non-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer non... December 26, 1996 for any ankle joint metal/polymer non-constrained cemented prosthesis that was...

  13. 21 CFR 888.3110 - Ankle joint metal/polymer semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ankle joint metal/polymer semi-constrained... Ankle joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an...

  14. 21 CFR 888.3120 - Ankle joint metal/polymer non-constrained cemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ankle joint metal/polymer non-constrained cemented... metal/polymer non-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer non... December 26, 1996 for any ankle joint metal/polymer non-constrained cemented prosthesis that was...

  15. Risk of degenerative ankle joint disease in volleyball players: study of former elite athletes.

    PubMed

    Gross, P; Marti, B

    1999-01-01

    To estimate the influence of long-term, high-intensity volleyball playing on premature osteoarthritis (OA) of the ankle joint, we examined a group of 22 former elite volleyball-players age (34 +/- 6 yrs.) who had played for at least 3 years in the highest volleyball league in Switzerland, and 19 normal healthy untrained controls (35 +/- 6 yrs.). Volleyball-athletes had played during an average of 5.5 (+/- 2) h/wk for 8.5 (+/- 3) yrs. Twenty of the 22 players had suffered from at least one ankle sprain (average: 3.5), 10 had had ruptures of the lateral ligaments (8 of them operated). Four players had severe mechanical instability, 5 a talar varus tilt in the stress X-ray of more than 8 degrees. Subchondral sclerosis and osteophytes were more prevalent in volleyballers than in controls (p < 0.001), while the difference in joint space was not significant. No severe grades of OA could be observed in these former elite volleyball players. Yet, a radiologic score of degenerative ankle disease was elevated in 19/22 of them, but only in 2/19 controls (p<0.001). In multiple regression analysis among athletes, the anterior drawer sign and a feeling of instability were the only significant and independent predictors of an increased radiological index (p = 0.003 and p = 0.02, respectively) from an initial set of 9 variables covering career length and intensity as volleyball player, clinical signs of ankle instability and age. Even if in the present study, athletes had clearly more radiologic findings than controls--such as spur formation and subchondral sclerosis--long-term, high-intensity volleyball playing alone could not be confirmed as an independent risk factor for OA of the ankle joint however, a combination of chronic lateral ankle instability with intensive volleyball playing could marginally increase the risk of ankle OA. PMID:10090465

  16. Primary meningococcal septic arthritis of the ankle joint: a case report.

    PubMed

    Gee, Christopher; Tandon, Tarang; Avasthi, Adish; Jerwood, Susie; Rao, Biyyam M; Cavanagh, Simon

    2014-01-01

    We present the case of a healthy 18-year-old female who presented with history of an acute onset, painful, swollen right ankle joint. Microbiologic samples from the ankle aspirate grew Neisseria meningitidis. She had had no previous contact with a patient with meningitis nor any existing or preceding clinical symptoms of meningitis. She was treated with surgical drainage with mini-open arthrotomy and a repeat washout at 48 hours. The identification of the organism was expedited using the Analytical Profiling Index (bioMérieux UK, Basingstoke, UK). Our patient was treated with 2 weeks of third-generation cephalosporin antibiotics. At the final follow-up visit, the inflammatory markers had returned to normal, with a normal ankle joint and no evidence of long-term sequelae of septic arthritis. Primary septic arthritis with N. meningitidis is exceptionally rare in the adult population and has been most often reported in the knee. To the best of our knowledge, this is the first reported case of primary septic arthritis of the native adult ankle joint in a healthy individual due to N. meningitides that was diagnosed and treated appropriately with no residual sequelae of the disease.

  17. Dynamic Postural-Stability Deficits After Cryotherapy to the Ankle Joint

    PubMed Central

    Fullam, Karl; Caulfield, Brian; Coughlan, Garrett F.; McGroarty, Mark; Delahunt, Eamonn

    2015-01-01

    Context  Decreased postural stability is a primary risk factor for lower limb musculoskeletal injuries. During athletic competitions, cryotherapy may be applied during short breaks in play or during half-time; however, its effects on postural stability remain unclear. Objective  To investigate the acute effects of a 15-minute ankle-joint cryotherapy application on dynamic postural stability. Design  Controlled laboratory study. Setting  University biomechanics laboratory. Patients or Other Participants  A total of 29 elite-level collegiate male field-sport athletes (age = 20.8 ± 1.12 years, height = 1.80 ± 0.06 m, mass = 81.89 ± 8.59 kg) participated. Intervention(s)  Participants were tested on the anterior (ANT), posterolateral (PL), and posteromedial (PM) reach directions of the Star Excursion Balance Test before and after a 15-minute ankle-joint cryotherapy application. Main Outcome Measure(s)  Normalized reach distances; sagittal-plane kinematics of the hip, knee, and ankle joints; and associated mean velocity of the center-of-pressure path during performance of the ANT, PL, and PM reach directions of the Star Excursion Balance Test. Results  We observed a decrease in reach-distance scores for the ANT, PL, and PM reach directions from precryotherapy to postcryotherapy (P < .05). No differences were observed in hip-, knee-, or ankle-joint sagittal-plane kinematics (P > .05). We noted a decrease in mean velocity of the center-of-pressure path from precryotherapy to postcryotherapy (P < .05) in all reach directions. Conclusions  Dynamic postural stability was adversely affected immediately after cryotherapy to the ankle joint. PMID:26285088

  18. A Novel Ultrasound Technique for Detection of Osteochondral Defects in the Ankle Joint: A Parametric and Feasibility Study

    PubMed Central

    Sarkalkan, Nazli; Loeve, Arjo J.; van Dongen, Koen W. A.; Tuijthof, Gabrielle J. M.; Zadpoor, Amir A.

    2015-01-01

    (Osteo)chondral defects (OCDs) in the ankle are currently diagnosed with modalities that are not convenient to use in long-term follow-ups. Ultrasound (US) imaging, which is a cost-effective and non-invasive alternative, has limited ability to discriminate OCDs. We aim to develop a new diagnostic technique based on US wave propagation through the ankle joint. The presence of OCDs is identified when a US signal deviates from a reference signal associated with the healthy joint. The feasibility of the proposed technique is studied using experimentally-validated 2D finite-difference time-domain models of the ankle joint. The normalized maximum cross correlation of experiments and simulation was 0.97. Effects of variables relevant to the ankle joint, US transducers and OCDs were evaluated. Variations in joint space width and transducer orientation made noticeable alterations to the reference signal: normalized root mean square error ranged from 6.29% to 65.25% and from 19.59% to 8064.2%, respectively. The results suggest that the new technique could be used for detection of OCDs, if the effects of other parameters (i.e., parameters related to the ankle joint and US transducers) can be reduced. PMID:25609040

  19. A novel ultrasound technique for detection of osteochondral defects in the ankle joint: a parametric and feasibility study.

    PubMed

    Sarkalkan, Nazli; Loeve, Arjo J; van Dongen, Koen W A; Tuijthof, Gabrielle J M; Zadpoor, Amir A

    2015-01-01

    (Osteo)chondral defects (OCDs) in the ankle are currently diagnosed with modalities that are not convenient to use in long-term follow-ups. Ultrasound (US) imaging, which is a cost-effective and non-invasive alternative, has limited ability to discriminate OCDs. We aim to develop a new diagnostic technique based on US wave propagation through the ankle joint. The presence of OCDs is identified when a US signal deviates from a reference signal associated with the healthy joint. The feasibility of the proposed technique is studied using experimentally-validated 2D finite-difference time-domain models of the ankle joint. The normalized maximum cross correlation of experiments and simulation was 0.97. Effects of variables relevant to the ankle joint, US transducers and OCDs were evaluated. Variations in joint space width and transducer orientation made noticeable alterations to the reference signal: normalized root mean square error ranged from 6.29% to 65.25% and from 19.59% to 8064.2%, respectively. The results suggest that the new technique could be used for detection of OCDs, if the effects of other parameters (i.e., parameters related to the ankle joint and US transducers) can be reduced.

  20. Biomechanics of the natural, arthritic, and replaced human ankle joint

    PubMed Central

    2014-01-01

    The human ankle joint complex plays a fundamental role in gait and other activities of daily living. At the same time, it is a very complicated anatomical system but the large literature of experimental and modelling studies has not fully described the coupled joint motion, position and orientation of the joint axis of rotation, stress and strain in the ligaments and their role in guiding and stabilizing joint motion, conformity and congruence of the articular surfaces, patterns of contact at the articular surfaces, patterns of rolling and sliding at the joint surfaces, and muscle lever arm lengths. The present review article addresses these issues as described in the literature, reporting the most recent relevant findings. PMID:24499639

  1. Intelligent stretching of ankle joints with contracture/spasticity.

    PubMed

    Zhang, Li-Qun; Chung, Sun G; Bai, Zhiqiang; Xu, Dali; van Rey, Elton M T; Rogers, Mark W; Johnson, Marjorie E; Roth, Elliot J

    2002-09-01

    An intelligent stretching device was developed to treat the spastic/contractured ankle of neurologically impaired patients. The device stretched the ankle safely throughout the range of motion (ROM) to extreme dorsiflexion and plantarflexion until a specified peak resistance torque was reached with the stretching velocity controlled based on the resistance torque. The ankle was held at the extreme position for a period of time to let stress relaxation occur before it was rotated back to the other extreme position. Stretching was slow at the joint extreme positions, making it possible to reach a larger ROM safely and it was fast in the middle ROM so the majority of the treatment was spent in stretching the problematic extreme ROM. Furthermore, the device evaluated treatment outcome quantitatively in multiple aspects, including active and passive ROM, joint stiffness and viscous damping and reflex excitability. The stretching resulted in considerable changes in joint passive ROM, stiffness, viscous damping and reflex gain. The intelligent control and yet simple design of the device suggest that with appropriate simplification, the device can be made portable and low cost, making it available to patients and therapists for frequent use in clinics/home and allowing more effective treatment and long-term improvement. PMID:12503779

  2. Joint stiffness of the ankle and the knee in running.

    PubMed

    Günther, Michael; Blickhan, Reinhard

    2002-11-01

    The spring-mass model is a valid fundament to understand global dynamics of fast legged locomotion under gravity. The underlying concept of elasticity, implying leg stiffness as a crucial parameter, is also found on lower motor control levels, i.e. in muscle-reflex and muscle-tendon systems. Therefore, it seems reasonable that global leg stiffness emerges from local elasticity established by appropriate joint torques. A recently published model of an elastically operating, segmented leg predicts that proper adjustment of joint elasticities to the leg geometry and initial conditions of ground contact provides internal leg stability. Another recent study suggests that in turn the leg segmentation and the initial conditions may be a consequence of metabolic and bone stress constraints. In this study, the theoretical predictions were verified experimentally with respect to initial conditions and elastic joint characteristics in human running. Kinematics and kinetics were measured and the joint torques were estimated by inverse dynamics. Stiffnesses and elastic nonlinearities describing the resulting joint characteristics were extracted from parameter fits. Our results clearly support the theoretical predictions: the knee joint is always stiffer and more extended than the ankle joint. Moreover, the knee torque characteristic on the average shows the higher nonlinearity. According to literature, the leg geometry is a consequence of metabolic and material stress limitations. Adapted to this given geometry, the initial joint angle conditions in fast locomotion are a compromise between metabolic and control effort minimisation. Based on this adaptation, an appropriate joint stiffness ratio between ankle and knee passively safeguards the internal leg stability. The identified joint nonlinearities contribute to the linearisation of the leg spring.

  3. Knee and ankle joint torque-angle relationships of multi-joint leg extension.

    PubMed

    Hahn, Daniel; Olvermann, Matthias; Richtberg, Jan; Seiberl, Wolfgang; Schwirtz, Ansgar

    2011-07-28

    The force-length-relation (F-l-r) is an important property of skeletal muscle to characterise its function, whereas for in vivo human muscles, torque-angle relationships (T-a-r) represent the maximum muscular capacity as a function of joint angle. However, since in vivo force/torque-length data is only available for rotational single-joint movements the purpose of the present study was to identify torque-angle-relationships for multi-joint leg extension. Therefore, inverse dynamics served for calculation of ankle and knee joint torques of 18 male subjects when performing maximum voluntary isometric contractions in a seated leg press. Measurements in increments of 10° knee angle from 30° to 100° knee flexion resulted in eight discrete angle configurations of hip, knee and ankle joints. For the knee joint we found an ascending-descending T-a-r with a maximum torque of 289.5° ± 43.3 Nm, which closely matches literature data from rotational knee extension. In comparison to literature we observed a shift of optimum knee angle towards knee extension. In contrast, the T-a-r of the ankle joint vastly differed from relationships obtained for isolated plantar flexion. For the ankle T-a-r derived from multi-joint leg extension subjects operated over different sections of the force-length curve, but the ankle T-a-r derived from isolated joint efforts was over the ascending limb for all subjects. Moreover, mean maximum torque of 234.7 ± 56.6 Nm exceeded maximal strength of isolated plantar flexion (185.7 ± 27.8 Nm). From these findings we conclude that muscle function between isolated and more physiological multi-joint tasks differs. This should be considered for ergonomic and sports optimisation as well as for modelling and simulation of human movement.

  4. Effect of a 6-week dynamic neuromuscular training programme on ankle joint function: A Case report

    PubMed Central

    2011-01-01

    Background Ankle joint sprain and the subsequent development of chronic ankle instability (CAI) are commonly encountered by clinicians involved in the treatment and rehabilitation of musculoskeletal injuries. It has recently been advocated that ankle joint post-sprain rehabilitation protocols should incorporate dynamic neuromuscular training to enhance ankle joint sensorimotor capabilities. To date no studies have reported on the effects of dynamic neuromuscular training on ankle joint positioning during landing from a jump, which has been reported as one of the primary injury mechanisms for ankle joint sprain. This case report details the effects of a 6-week dynamic neuromuscular training programme on ankle joint function in an athlete with CAI. Methods The athlete took part in a progressive 6-week dynamic neuromuscular training programme which incorporated postural stability, strengthening, plyometric, and speed/agility drills. The outcome measures chosen to assess for interventional efficacy were: [1] Cumberland Ankle Instability Tool (CAIT) scores, [2] Star Excursion Balance Test (SEBT) reach distances, [3] ankle joint plantar flexion during drop landing and drop vertical jumping, and [4] ground reaction forces (GRFs) during walking. Results CAIT and SEBT scores improved following participation in the programme. The angle of ankle joint plantar flexion decreased at the point of initial contact during the drop landing and drop vertical jumping tasks, indicating that the ankle joint was in a less vulnerable position upon landing following participation in the programme. Furthermore, GRFs were reduced whilst walking post-intervention. Conclusions The 6-week dynamic neuromuscular training programme improved parameters of ankle joint sensorimotor control in an athlete with CAI. Further research is now required in a larger cohort of subjects to determine the effects of neuromuscular training on ankle joint injury risk factors. PMID:21658224

  5. Can Chronic Ankle Instability be Prevented? Rethinking Management of Lateral Ankle Sprains.

    ERIC Educational Resources Information Center

    Denegar, Craig R.; Miller, Sayers J., III

    2002-01-01

    Investigates whether chronic ankle instability can be prevented, discussing: the relationship between mechanical and functional instability; normal ankle mechanics, sequelae to lateral ankle sprains, and abnormal ankle mechanics; and tissue healing, joint dysfunction, and acute lateral ankle sprain management. The paper describes a treatment model…

  6. The joints of the evolving foot. Part I. The ankle joint.

    PubMed Central

    Lewis, O J

    1980-01-01

    Evidence is presented to suggest that the eutherian ankle joint has been derived from a meniscus-containing joint such as that found in extant arboreal marsupials. Probable morphological derivatives of this meniscus are identifiable in the Eutheria. The form and function of the joint are described in sub-human Primates and the adaptations which characterize the joint in bipedal man are noted. These morphological findings permit some speculation about the palaeocology of the earliest mammals with particular reference to the emergence of the order Primates. PMID:7410197

  7. Four Weeks of Balance Training does not Affect Ankle Joint Stiffness in Subjects with Unilateral Chronic Ankle Instability

    PubMed Central

    Jain, Tarang Kumar; Wauneka, Clayton N.; Liu, Wen

    2016-01-01

    Background Balance training has been shown to be effective in preventing ankle sprain recurrences in subjects with chronic ankle instability (CAI) but the biomechanical pathways underlying the clinical outcomes are still unknown. This study was conducted to determine if a 4-week balance training intervention can alter the mechanical characteristics in ankles with CAI. Methods Twenty-two recreationally active subjects with unilateral CAI were randomized to either a control (n = 11, 35.1 ± 9.3 years) or intervention (n = 11, 33.5 ± 6.6 years) group. Subjects in the intervention group were trained on the affected limb with static and dynamic components using a Biodex balance stability system for 4-weeks. The ankle joint stiffness and neutral zone in inversion and eversion directions on the involved and uninvolved limbs was measured at baseline and post-intervention using a dynamometer. Results At baseline, the mean values of the inversion stiffness (0.69 ± 0.37 Nm/degree) in the involved ankle was significantly lower (p < 0.011, 95% CI [0.563, 0.544]) than that of uninvolved contralateral ankle (0.99 ± 0.41 Nm/degree). With the available sample size, the eversion stiffness, inversion neutral zone, and eversion neutral zone were not found to be significantly different between the involved and uninvolved contralateral ankles. The 4-week balance training intervention failed to show any significant effect on the passive ankle stiffness and neutral zones in inversion and eversion. Conclusion Decreased inversion stiffness in the involved chronic unstable ankle was found that of uninvolved contralateral ankle. The 4-week balance training program intervention was ineffective in altering the mechanical characteristics of ankles with CAI. Level of evidence Randomized controlled clinical trial; Level of evidence, 1. PMID:27642647

  8. Effects of Kinesio taping on joint position sense of the ankle

    PubMed Central

    Seo, Hyun-Do; Kim, Min-Young; Choi, Jung-Eun; Lim, Ga-Hee; Jung, Seong-In; Park, So-Hyun; Cheon, Song-Hee; Lee, Hae-Yong

    2016-01-01

    [Purpose] The purpose of this study was to examine the effect of Kinesio taping on the joint position sense of the ankle. [Subjects and Methods] The subjects of this study were 26 nomal adults who had experienced ankle sprain. Kinesio taping was applied over the ankle medial ligament and ankle lateral ligament with eight pattern reinforcement taping. Joint position sense was measured using isokinetic equipment (Biodex System 4 pro dynamometer, Biodex Medical systems Inc., USA) during dorsiflexion/plantarflexion and inversion/eversion, before and after taping. Statistical analyses were performed using SPSS 21.0 for Windows. [Results] Joint position sense after Kinesio taping was improved in the dorsiflexion and inversion positions. [Conclusion] According to the results of this study, Kinesio taping of the ankle is effective for the prevention of ankle sprain. PMID:27190446

  9. Comparative study on isokinetic capacity of knee and ankle joints by functional injury.

    PubMed

    Jeon, Kyoungkyu; Seo, Byoung-Do; Lee, Sang-Ho

    2016-01-01

    [Purpose] To collect basic data for exercise programs designed to enhance functional knee and ankle joint stability based on isokinetic measurement and muscle strength evaluations in normal and impaired functional states. [Subjects and Methods] Twenty-four subjects were randomly assigned to the athlete group and the control group (n = 12 each). Data were collected of isokinetic knee extensor and flexor strength at 60°/sec, 180°/sec, and 240°/sec and ankle plantar and dorsiflexor strength at 30°/sec and 120°/sec. [Results] Significant intergroup differences were observed in peak torque of the right extensors at 60°/sec, 180°/sec, and 240°/sec and the right flexors at 240°/sec. Significant differences were observed in peak torque/body weight in the right extensors at 60°/sec, 180°/sec, and 240°/sec and in the right flexors at 180°/sec and 240°/sec. Significant peak torque differences were noted in the left ankle joint dorsiflexor at 30°/sec and 120°/sec, right plantar flexor at 120°/sec, left plantar flexor at 30°/sec, left dorsiflexor at 30°/sec and 120°/sec, and right dorsiflexor at 120°/sec. [Conclusion] Isokinetic evaluation stimulates muscle contraction at motion-dependent speeds and may contribute to the development of intervention programs to improve knee and ankle joint function and correct lower-extremity instability.

  10. Comparative study on isokinetic capacity of knee and ankle joints by functional injury

    PubMed Central

    Jeon, Kyoungkyu; Seo, Byoung-Do; Lee, Sang-Ho

    2016-01-01

    [Purpose] To collect basic data for exercise programs designed to enhance functional knee and ankle joint stability based on isokinetic measurement and muscle strength evaluations in normal and impaired functional states. [Subjects and Methods] Twenty-four subjects were randomly assigned to the athlete group and the control group (n = 12 each). Data were collected of isokinetic knee extensor and flexor strength at 60°/sec, 180°/sec, and 240°/sec and ankle plantar and dorsiflexor strength at 30°/sec and 120°/sec. [Results] Significant intergroup differences were observed in peak torque of the right extensors at 60°/sec, 180°/sec, and 240°/sec and the right flexors at 240°/sec. Significant differences were observed in peak torque/body weight in the right extensors at 60°/sec, 180°/sec, and 240°/sec and in the right flexors at 180°/sec and 240°/sec. Significant peak torque differences were noted in the left ankle joint dorsiflexor at 30°/sec and 120°/sec, right plantar flexor at 120°/sec, left plantar flexor at 30°/sec, left dorsiflexor at 30°/sec and 120°/sec, and right dorsiflexor at 120°/sec. [Conclusion] Isokinetic evaluation stimulates muscle contraction at motion-dependent speeds and may contribute to the development of intervention programs to improve knee and ankle joint function and correct lower-extremity instability. PMID:26957768

  11. Ankle brachial pressure index of normal, healthy, younger adults.

    PubMed

    Niblo, Jane; Coull, Alison

    Doppler ultrasound and ankle brachial pressure index (ABPI) calculations are used in the assessment of lower limb vascularity, specifically to determine arterial deficiency. ABPI is important as it is used as an indicator when deciding management options for the treatment of leg ulceration. This study aimed to investigate the range of ABPI measurement, using Doppler ultrasound and sphygmomanometry in 36 young healthy adults aged 18-55 years. The findings show a mean ABPI in the left leg of 1.19 and a mean ABPI of 1.17 in the right leg which, while within the normal range, are consistently in the upper range and significantly higher than the acknowledged 'normal' midpoint of 1.0. It would appear that younger people will have ABPIs within the upper aspect of the normal range and well above the established norm of 1.0. PMID:24151719

  12. Combined medial displacement calcaneal osteotomy, subtalar joint arthrodesis, and ankle arthrodiastasis for end-stage posterior tibial tendon dysfunction.

    PubMed

    Stapleton, John J; Belczyk, Ronald; Zgonis, Thomas; Polyzois, Vasilios D

    2009-04-01

    Combining an ankle arthrodiastasis with a medial displacement calcaneal osteotomy and a subtalar joint arthrodesis offers surgeons a joint-sparing procedure for young and active patients who have end-stage posterior tibial tendon dysfunction and ankle joint involvement. An isolated subtalar joint arthrodesis or triple arthrodesis combined with an ankle arthrodiastasis is an option that can be used in certain case scenarios. Delaying the need for a joint destructive procedure through an ankle arthrodiastasis, however, may have a great impact in the near future, as advancements are underway to improve the use of ankle endoprosthesis. PMID:19389602

  13. Effects of wearing ankle weight on knee joint repositioning sense in the elderly

    PubMed Central

    Kim, Sooyoung; Jung, Daeun; Han, Jintae; Jung, Jaemin

    2016-01-01

    [Purpose] To investigate the effects of different ankle weights on knee joint repositioning sense in elderly individuals. [Subjects and Methods] Twenty-one subjects were divided for assessment as follows: young (20–30 years, n=10) and elderly (60–70 years, n=11). Knee joint repositioning error was measured by asking the subjects to reposition the target angle of their knee joints while wearing different ankle weights (0%, 0.5%, 1%, and 1.5%) in an open kinetic chain. The Hawk Digital System (60 Hz; Motion Analysis, Santa Rosa, CA, USA) was used to measure knee joint repositioning error. Differences in knee joint repositioning error between the young and elderly groups according to ankle weight load were examined by using two-way mixed repeated-measures analysis of variance. [Results] The knee joint repositioning error was lower with than without ankle weights in both groups. The error value was lowest with the 1.0% weight, though not significantly. Knee joint repositioning error was significantly higher in the elderly under all the ankle weight conditions. [Conclusion] Knee joint repositioning sense can be improved in elderly individuals by wearing proper ankle weights. However, weights that are too heavy might disturb knee joint positioning sense. PMID:27799664

  14. [Sports-induced epiphyseal injuries of the knee and ankle joint].

    PubMed

    Krüger-Franke, M; Vaeltl, M; Trouillier, H; Pförringer, W

    1994-06-01

    We report on the clinical and radiological follow-up results of 37 patients with epiphyseal injuries of the knee and ankle joint who were treated in our hospital between 1985 and 1990. Most of the ankle joint injuries were sustained during track and field, soccer and basketball, and most of the knee injuries during alpine skiing. The different mechanisms of injuries of the knee and ankle joint are discussed on the basis of our own results. The therapy considers the age of patient as well as localisation and type of the epiphyseal injury. In spite of this, growth disturbances occurred in 12.5% of the ankle joint and in 9.5% of the knee joint injuries.

  15. Biologic resurfacing of the ankle and first metatarsophalangeal joint: case studies with a 2-year follow-up.

    PubMed

    Brigido, Stephen A; Troiano, Michael; Schoenhaus, Harold

    2009-10-01

    The goal of biologic resurfacing is to provide a smooth joint surface with a low coefficient of friction, which allows the joint to function with near normal biomechanics, as well as provide intermittent pressure, to the subchondral and cancellous bone. This unique combination often results in the formation of a "neocartilage-like" structure that can reduce pain and restore biomechanics. As well as giving a brief history of cutis arthroplasty, this article describes cases in which the ankle and first metatarsophalangeal joint underwent biologic resurfacing, with a 2-year postoperative follow up.

  16. Modeling and stress analyses of a normal foot-ankle and a prosthetic foot-ankle complex.

    PubMed

    Ozen, Mustafa; Sayman, Onur; Havitcioglu, Hasan

    2013-01-01

    Total ankle replacement (TAR) is a relatively new concept and is becoming more popular for treatment of ankle arthritis and fractures. Because of the high costs and difficulties of experimental studies, the developments of TAR prostheses are progressing very slowly. For this reason, the medical imaging techniques such as CT, and MR have become more and more useful. The finite element method (FEM) is a widely used technique to estimate the mechanical behaviors of materials and structures in engineering applications. FEM has also been increasingly applied to biomechanical analyses of human bones, tissues and organs, thanks to the development of both the computing capabilities and the medical imaging techniques. 3-D finite element models of the human foot and ankle from reconstruction of MR and CT images have been investigated by some authors. In this study, data of geometries (used in modeling) of a normal and a prosthetic foot and ankle were obtained from a 3D reconstruction of CT images. The segmentation software, MIMICS was used to generate the 3D images of the bony structures, soft tissues and components of prosthesis of normal and prosthetic ankle-foot complex. Except the spaces between the adjacent surface of the phalanges fused, metatarsals, cuneiforms, cuboid, navicular, talus and calcaneus bones, soft tissues and components of prosthesis were independently developed to form foot and ankle complex. SOLIDWORKS program was used to form the boundary surfaces of all model components and then the solid models were obtained from these boundary surfaces. Finite element analyses software, ABAQUS was used to perform the numerical stress analyses of these models for balanced standing position. Plantar pressure and von Mises stress distributions of the normal and prosthetic ankles were compared with each other. There was a peak pressure increase at the 4th metatarsal, first metatarsal and talus bones and a decrease at the intermediate cuneiform and calcaneus bones, in

  17. Modeling and stress analyses of a normal foot-ankle and a prosthetic foot-ankle complex.

    PubMed

    Ozen, Mustafa; Sayman, Onur; Havitcioglu, Hasan

    2013-01-01

    Total ankle replacement (TAR) is a relatively new concept and is becoming more popular for treatment of ankle arthritis and fractures. Because of the high costs and difficulties of experimental studies, the developments of TAR prostheses are progressing very slowly. For this reason, the medical imaging techniques such as CT, and MR have become more and more useful. The finite element method (FEM) is a widely used technique to estimate the mechanical behaviors of materials and structures in engineering applications. FEM has also been increasingly applied to biomechanical analyses of human bones, tissues and organs, thanks to the development of both the computing capabilities and the medical imaging techniques. 3-D finite element models of the human foot and ankle from reconstruction of MR and CT images have been investigated by some authors. In this study, data of geometries (used in modeling) of a normal and a prosthetic foot and ankle were obtained from a 3D reconstruction of CT images. The segmentation software, MIMICS was used to generate the 3D images of the bony structures, soft tissues and components of prosthesis of normal and prosthetic ankle-foot complex. Except the spaces between the adjacent surface of the phalanges fused, metatarsals, cuneiforms, cuboid, navicular, talus and calcaneus bones, soft tissues and components of prosthesis were independently developed to form foot and ankle complex. SOLIDWORKS program was used to form the boundary surfaces of all model components and then the solid models were obtained from these boundary surfaces. Finite element analyses software, ABAQUS was used to perform the numerical stress analyses of these models for balanced standing position. Plantar pressure and von Mises stress distributions of the normal and prosthetic ankles were compared with each other. There was a peak pressure increase at the 4th metatarsal, first metatarsal and talus bones and a decrease at the intermediate cuneiform and calcaneus bones, in

  18. Ultrasound and magnetic resonance imaging of healthy paediatric ankles and knees: a baseline for comparison with haemophilic joints.

    PubMed

    Keshava, S N; Gibikote, S V; Mohanta, A; Poonnoose, P; Rayner, T; Hilliard, P; Lakshmi, K M; Moineddin, R; Ignas, D; Srivastava, A; Blanchette, V; Doria, A S

    2015-05-01

    The study was undertaken to document cartilage and soft tissue changes/findings in ankles and knees of normal children of different age groups to be used for comparison in the assessment of children with haemophilia. Cartilage thickness and soft tissue changes were recorded at predetermined sites of ankles/knees on both US and MRI in healthy boys in three age groups: 7-9; 10-14; and 15-18 years. To assess the validity of the ultrasound and MRI measurements, an ex vivo study was done using agar phantoms with techniques and scanners similar to those applied in vivo. Twenty (48%) knees and 22 (52%) ankles of 42 boys, were evaluated. There was a reduction in the thickness of joint cartilage with age. A difference in cartilage measurements was noted in most sites between the age groups on both US and MRI (P < 0.05 each), but such difference was not noted for joint fluid in ankles or knees (P = 0.20, P = 0.68 or P = 0.75, P = 0.63 for US, MRI, respectively). Although cartilage measurements were smaller on US than on MRI for both ankles and knees (P < 0.05 each), this observation was not recorded for fluid in knees (P = 0.02). For diminutive measurements (2 mm) mean US measurements were smaller than corresponding phantom's measurements, P = 0.02. Age-related measurements were noted for cartilage thickness on US and MRI in ankles and knees. US measurements were smaller than corresponding MRI measurements at most joint sites, which were supported by results on small-diameter phantoms.

  19. Dynamics of the ankle joint analyzed through moment-angle loops during human walking: gender and age effects.

    PubMed

    Crenna, Paolo; Frigo, Carlo

    2011-12-01

    Aim of this study was to provide a non-invasive assessment of the dynamic properties of the ankle joint during human locomotion, with specific focus on the effects of gender and age. Accordingly, flexion-extension angles and moments, obtained through gait analysis, were used to generate moment-angle loops at the ankle joint in 120 healthy subjects walking at a same normalized speed. Four reproducible types of loops were identified: Typical Loops, Narrow, Large and Yielding loops. No significant changes in the slopes of the main loop phases were observed as a function of gender and age, with the exception of a relative increase in the slope of the descending phase in elderly males compared to adult females. As for the ergometric parameters, the peak ankle moment, work produced and net work along the cycle were slightly, but significantly affected, with progressively decrease in the following order: Adult Males, Adult Females, Elderly Males and Elderly Females. The evidence that only few of the quantitative aspects of moment-angle loops were affected suggests that the control strategy which regulates the biomechanical properties of the ankle joint during walking is rather robust and qualitatively consistent across genders and age.

  20. Footwear affects the gearing at the ankle and knee joints during running.

    PubMed

    Braunstein, Bjoern; Arampatzis, Adamantios; Eysel, Peer; Brüggemann, Gert-Peter

    2010-08-10

    The objective of the study was to investigate the adjustment of running mechanics by wearing five different types of running shoes on tartan compared to barefoot running on grass focusing on the gearing at the ankle and knee joints. The gear ratio, defined as the ratio of the moment arm of the ground reaction force (GRF) to the moment arm of the counteracting muscle tendon unit, is considered to be an indicator of joint loading and mechanical efficiency. Lower extremity kinematics and kinetics of 14 healthy volunteers were quantified three dimensionally and compared between running in shoes on tartan and barefoot on grass. Results showed no differences for the gear ratios and resultant joint moments for the ankle and knee joints across the five different shoes, but showed that wearing running shoes affects the gearing at the ankle and knee joints due to changes in the moment arm of the GRF. During barefoot running the ankle joint showed a higher gear ratio in early stance and a lower ratio in the late stance, while the gear ratio at the knee joint was lower during midstance compared to shod running. Because the moment arms of the counteracting muscle tendon units did not change, the determinants of the gear ratios were the moment arms of the GRF's. The results imply higher mechanical stress in shod running for the knee joint structures during midstance but also indicate an improved mechanical advantage in force generation for the ankle extensors during the push-off phase.

  1. The effect of talo-crural joint manipulation on range of motion at the ankle joint in subjects with a history of ankle injury.

    PubMed

    Andersen, Skye; Fryer, Gary A; McLaughlin, Patrick

    2003-07-01

    Introduction: There is little research available on the effects of peripheral joint manipulation. Only a few studies have examined the effect of manipulation on ankle range of motion, with conflicting results. This study aimed to determine whether a single high-velocity, low-amplitude (HVLA) thrust manipulation to the talo-crural joint altered ankle range of motion in subjects with a history of lateral ligament sprain.Methods: Male and female volunteers (N=52) with a history of lateral ligament sprain were randomly assigned into either an experimental group (n=26) or a control group (n=26). Those in the experimental group received a single HVLA thrust to the talo-crural joint, whilst those in the control group received no treatment intervention. Pre-test and post-test measurements of passive dorsiflexion range of motion were taken.Results: No significant changes in dorsiflexion range of motion were detected between manipulated ankles and those of control subjects using dependent and independent t-tests. Ankles that cavitated displayed a greater mean DFR and large effect size (d=0.8) compared to those that did not gap and cavitate, but analysis with ANOVA revealed these differences to be not significant.Conclusion: HVLA manipulation of the ankle did not increase dorsiflexion range of motion in subjects with a history of lateral ligament sprain.

  2. Design and simulation of a cable-pulley-based transmission for artificial ankle joints

    NASA Astrophysics Data System (ADS)

    Liu, Huaxin; Ceccarelli, Marco; Huang, Qiang

    2016-06-01

    In this paper, a mechanical transmission based on cable pulley is proposed for human-like actuation in the artificial ankle joints of human-scale. The anatomy articular characteristics of the human ankle is discussed for proper biomimetic inspiration in designing an accurate, efficient, and robust motion control of artificial ankle joint devices. The design procedure is presented through the inclusion of conceptual considerations and design details for an interactive solution of the transmission system. A mechanical design is elaborated for the ankle joint angular with pitch motion. A multi-body dynamic simulation model is elaborated accordingly and evaluated numerically in the ADAMS environment. Results of the numerical simulations are discussed to evaluate the dynamic performance of the proposed design solution and to investigate the feasibility of the proposed design in future applications for humanoid robots.

  3. Effects of Deep Brain Stimulation and Medication on Strength, Bradykinesia, and Electromyographic Patterns of the Ankle Joint in Parkinson’s Disease

    PubMed Central

    Vaillancourt, David E.; Prodoehl, Janey; Sturman, Molly M.; Bakay, Roy A.E.; Metman, Leo Verhagen; Corcos, Daniel M.

    2008-01-01

    We investigated the control of movement in 12 patients with Parkinson’s disease (PD) after they received surgically implanted high-frequency stimulating electrodes in the subthalamic nucleus (STN). The experiment studied ankle strength, movement velocity, and the associated electromyographic patterns in PD patients, six of whom had tremor at the ankle. The patients were studied off treatment, ON STN deep brain stimulation (DBS), on medication, and on medication plus STN DBS. Twelve matched control subjects were also examined. Medication alone and STN DBS alone increased patients’ ankle strength, ankle velocity, agonist muscle burst amplitude, and agonist burst duration, while reducing the number of agonist bursts during movement. These findings were similar for PD patients with and without tremor. The combination of medication plus STN DBS normalized maximal strength at the ankle joint, but ankle movement velocity and electromyographic patterns were not normalized. The findings are the first to demonstrate that STN DBS and medication increase strength and movement velocity at the ankle joint. PMID:16124011

  4. In vivo kinematics of the talocrural and subtalar joints with functional ankle instability during weight-bearing ankle internal rotation: a pilot study.

    PubMed

    Kobayashi, Takumi; No, Yumi; Yoneta, Kei; Sadakiyo, Masashi; Gamada, Kazuyoshi

    2013-06-01

    Functional ankle instability (FAI) may involve abnormal kinematics. However, reliable quantitative data for kinematics of FAI have not been reported. The objective of this study was to determine if the abnormal kinematics exist in the talocrural and subtalar joints in patients with FAI. Five male subjects with unilateral FAI (a mean age of 33.4 ± 13.2 years) were enrolled. All subjects were examined with stress radiography and found to have no mechanical ankle instability (MAI). Lateral radiography at weight-bearing ankle internal rotation of 0° and 20° was taken with the ankle at 30° dorsiflexion and 30° plantar flexion. Patients underwent computed tomography scan at 1.0 mm slice pitch spanning distal one third of the lower leg and the distal end of the calcaneus. Three-dimensional (3D) kinematics of the talocrural and subtalar joints as well as the ankle joint complex (AJC) were determined using a 3D-to-2D registration technique using a 3D-to-2D registration technique with 3D bone models and plain radiography. FAI joints in ankle dorsiflexion demonstrated significantly greater subtalar internal rotation from 0° to 20° internal rotation. No statistical differences in plantar flexion were detected in talocrural, subtalar or ankle joint complex kinematics between the FAI and contralateral healthy joints. During ankle internal rotation in dorsiflexion, FAI joints demonstrated greater subtalar internal rotation. The FAI joints without mechanical instability presented abnormal kinematics. This suggests that abnormal kinematics of the FAI joints may contribute to chronic instability. FAI joints may involve unrecognized abnormal subtalar kinematics during internal rotation in ankle dorsiflexion which may contribute to chronic instability and frequent feelings of instability.

  5. Ultrasound-Guided Interventional Procedures in Pain Medicine: A Review of Anatomy, Sonoanatomy, and Procedures: Part VI: Ankle Joint.

    PubMed

    Soneji, Neilesh; Peng, Philip W H

    2016-01-01

    Ultrasound-guided injections in pain medicine are emerging as a popular technique for pain interventions. Ultrasound can be applied for procedures of the ankle joint and surrounding structures. This review describes the anatomy and sonoanatomy of the ankle joint, subtalar joint, and surrounding extra-articular structures relevant for intra-articular injection. Second, it reviews injection techniques and the accuracy and efficacy of these intra-articular ankle injections.

  6. Ibuprofen in the treatment of acute ankle joint injuries. A double-blind study.

    PubMed

    Fredberg, U; Hansen, P A; Skinhøj, A

    1989-01-01

    Sixty-eight patients who presented to the casualty ward with acute ankle joint injuries were studied to examine the effect of ibuprofen on pain and ankle swelling. Thirty-two patients were treated with placebo tablets and 36 with 600 mg ibuprofen tablets taken four times a day for 4 to 6 days. All of the patients were immobilized and requested to keep the foot elevated. The results showed that ibuprofen had no effect on the ankle swelling. The need for additional analgesics was not influenced by treatment with ibuprofen, which means that ibuprofen has no effect on pain. The time elapsed from occurrence of the injury to arrival at the casualty ward was negatively correlated to the reduction of ankle joint swelling during the treatment period. Treatment with ice-sprays, icebags, or cold water during the acute stage of injury did not influence the reduction of swelling during the treatment period. PMID:2675651

  7. Ankle rehabilitation device with two degrees of freedom and compliant joint

    NASA Astrophysics Data System (ADS)

    Racu (Cazacu, C.-M.; Doroftei, I.

    2015-11-01

    We propose a rehabilitation device that we intend to be low cost and easy to manufacture. The system will ensure functionality but also have a small dimensions and low mass, considering the physiological dimensions of the foot and lower leg. To avoid injure of the ankle joint, this device is equipped with a compliant joint between the motor and mechanical transmission. The torque of this joint is intended to be adjustable, according to the degree of ankle joint damage. To choose the material and the dimensions of this compliant joint, in this paper we perform the first stress simulation. The minimum torque is calculated, while the maximum torque is given by the preliminary chosen actuator.

  8. Proprioceptive impairments associated with knee osteoarthritis are not generalized to the ankle and elbow joints.

    PubMed

    Shanahan, Camille J; Wrigley, Tim V; Farrell, Michael J; Bennell, Kim L; Hodges, Paul W

    2015-06-01

    The mechanisms for proprioceptive changes associated with knee osteoarthritis (OA) remain elusive. Observations of proprioceptive changes in both affected knees and other joints imply more generalized mechanisms for proprioceptive impairment. However, evidence for a generalized effect remains controversial. This study examined whether joint repositioning proprioceptive deficits are localized to the diseased joint (knee) or generalized across other joints (elbow and ankle) in people with knee OA. Thirty individuals with right knee OA (17 female, 66±7 [mean±SD] years) of moderate/severe radiographic disease severity and 30 healthy asymptomatic controls of comparable age (17 female, 65±8years) performed active joint repositioning tests of the knee, ankle and elbow in randomised order in supine. Participants with knee OA had a larger relative error for joint repositioning of the knee than the controls (OA: 2.7±2.1°, control: 1.6±1.7°, p=.03). Relative error did not differ between groups for the ankle (OA: 2.2±2.5°, control: 1.9±1.3°, p=.50) or elbow (OA: 2.5±3.3°, control: 2.9±2.8°, p=.58). These results are consistent with a mechanism for proprioceptive change that is localized to the knee joint. This could be mediated by problems with mechanoreceptors, processing/relay of somatosensory input to higher centers, or joint-specific interference with cognitive processes by pain.

  9. A 4-Week Neuromuscular Training Program and Gait Patterns at the Ankle Joint

    PubMed Central

    Coughlan, Garrett; Caulfield, Brian

    2007-01-01

    Context: Previous research into the rehabilitation of ankle sprains has primarily focused on outcome measures that do not replicate functional activities, thus making it difficult to extrapolate the results relative to the weight-bearing conditions under which most ankle sprains occur. Objective: To measure the effects of a training program on gait during walking and running in an active athletic population. Design: Matched-pairs, controlled trial. Setting: University motion analysis laboratory. Patients or Other Participants: Ten subjects from an athletic population (7 healthy, 3 with functional ankle instability: age = 25.8 ± 3.9 years, height = 177.6 ± 6.1 cm, mass = 66.8 ± 7.4 kg) and 10 controls matched for age, sex, activity, and ankle instability (7 healthy, 3 with functional ankle instability: age = 27.4 ± 5.8 years, height = 178.7 ± 10.8 cm, mass = 71.6 ± 10.0 kg). Intervention(s): A 4-week neuromuscular training program undertaken by the treatment group. Main Outcome Measure(s): We measured ankle position and velocity in the frontal (x) and sagittal (y) planes in all subjects during treadmill walking and running for the periods 100 milliseconds before heel strike, at heel strike, and 100 milliseconds after heel strike. Results: A 4-week neuromuscular training program resulted in no significant changes in ankle position or velocity during treadmill walking and running. Conclusions: The mechanisms by which neuromuscular training improves function in normal subjects and those with functional ankle instability do not appear to result in measurable changes in gait kinematics. Our findings raise issues regarding methods of ankle sprain rehabilitation and the measurement of their effectiveness in improving functional activities. Further research in a larger population with functional ankle instability is necessary. PMID:17597944

  10. [Ultrasound in complex of radiological studies in diagnosis of ankle joint medial aspect pathologies].

    PubMed

    Gurgenidze, T; Mizandari, M

    2011-10-01

    The aim of the research is to study sonosemiotics of ankle joint pathology by means of ultrasound in order to optimize the diagnostic process and improve the treatment. 130 patients (age ranges from 5 to 70 years) underwent the radiological study of ankle joint medial aspect. Pathology types: degenerative-dystrophic diseases - 39 (30%), inflammatory pathology - 21 (16.2%), traumatic injuries - 20 (15.2%), vascular pathologies - 26 (20%), neurogenic problems -7 (5.4%), soft tissue neoplasms - 5 (3.8%), congenital anomalies - 7 (5.4%) and vertebral pathology - 5 (4.0%). The diagnostic studies include: a) Ultrasound, performed on digital ultrasound system using high frequency (7.5-12.0 MHz) linear probe with Doppler capability (all patients); b) X-Ray filming in antero-posterior and lateral projections (6 patients- 4.5%); c) MRI - T1 and T2 weighted images in saggital and transverse planes 10 patients (10.0%) and d) CT - 2 patients (1.5%); To 2 (1.5%) patient biopsy has been performed. This study showed that ultrasound was successful in ankle joint medial aspect pathology diagnosis in 108 cases (84.0%); It was ineffective in osseous pathology definition. In final diagnosis of impingment syndrom MRI was required in 4 (3.6%) cases. It is concluded that ultrasound should be used as a Gold Standard in diagnosis of localized pain and swelling in the ankle joint.

  11. Quadruple-component superficial circumflex iliac artery perforator (SCIP) flap: A chimeric SCIP flap for complex ankle reconstruction of an exposed artificial joint after total ankle arthroplasty.

    PubMed

    Yamamoto, Takumi; Saito, Takafumi; Ishiura, Ryohei; Iida, Takuya

    2016-09-01

    Total ankle arthroplasty (TAA) is becoming popular in patients with rheumatoid arthritis (RA)-associated ankle joint degeneration. However, ankle wound complications can occur after TAA, which sometimes requires challenging reconstruction due to anatomical complexity of the ankle. Superficial circumflex iliac artery (SCIA) perforator (SCIP) flap has been reported to be useful for various reconstructions, but no case has been reported regarding a chimeric SCIP flap for complex ankle reconstruction. We report a case of complex ankle defect successfully reconstructed with a free quadruple-component chimeric SCIP flap. A 73-year-old female patient with RA underwent TAA, and suffered from an extensive ankle soft tissue defect (13 × 5 cm) with exposure of the implanted artificial joint and the extensor tendons. A chimeric SCIP flap was raised based on the deep branch and the superficial branch of the SCIA, which included chimeric portions of the sartorius muscle, the deep fascia, the inguinal lymph node (ILN), and the skin/fat. The flap was transferred to the recipient ankle. The sartorius muscle was used to cover the artificial joint, the deep fascia to reconstruct the extensor retinaculum, the ILN to prevent postoperative lymphedema, and the adiposal tissue to put around the extensor tendons for prevention of postoperative adhesion. Postoperatively, the patient could walk by herself without persistent leg edema or bowstringing of the extensor tendons, and was satisfied with the concealable donor scar. Although further studies are required to confirm efficacy, multicomponent chimeric SCIP has a potential to be a useful option for complex defects of the ankle. PMID:27423250

  12. Quadruple-component superficial circumflex iliac artery perforator (SCIP) flap: A chimeric SCIP flap for complex ankle reconstruction of an exposed artificial joint after total ankle arthroplasty.

    PubMed

    Yamamoto, Takumi; Saito, Takafumi; Ishiura, Ryohei; Iida, Takuya

    2016-09-01

    Total ankle arthroplasty (TAA) is becoming popular in patients with rheumatoid arthritis (RA)-associated ankle joint degeneration. However, ankle wound complications can occur after TAA, which sometimes requires challenging reconstruction due to anatomical complexity of the ankle. Superficial circumflex iliac artery (SCIA) perforator (SCIP) flap has been reported to be useful for various reconstructions, but no case has been reported regarding a chimeric SCIP flap for complex ankle reconstruction. We report a case of complex ankle defect successfully reconstructed with a free quadruple-component chimeric SCIP flap. A 73-year-old female patient with RA underwent TAA, and suffered from an extensive ankle soft tissue defect (13 × 5 cm) with exposure of the implanted artificial joint and the extensor tendons. A chimeric SCIP flap was raised based on the deep branch and the superficial branch of the SCIA, which included chimeric portions of the sartorius muscle, the deep fascia, the inguinal lymph node (ILN), and the skin/fat. The flap was transferred to the recipient ankle. The sartorius muscle was used to cover the artificial joint, the deep fascia to reconstruct the extensor retinaculum, the ILN to prevent postoperative lymphedema, and the adiposal tissue to put around the extensor tendons for prevention of postoperative adhesion. Postoperatively, the patient could walk by herself without persistent leg edema or bowstringing of the extensor tendons, and was satisfied with the concealable donor scar. Although further studies are required to confirm efficacy, multicomponent chimeric SCIP has a potential to be a useful option for complex defects of the ankle.

  13. Interventions for increasing ankle joint dorsiflexion: a systematic review and meta-analysis

    PubMed Central

    2013-01-01

    Background Ankle joint equinus, or restricted dorsiflexion range of motion (ROM), has been linked to a range of pathologies of relevance to clinical practitioners. This systematic review and meta-analysis investigated the effects of conservative interventions on ankle joint ROM in healthy individuals and athletic populations. Methods Keyword searches of Embase, Medline, Cochrane and CINAHL databases were performed with the final search being run in August 2013. Studies were eligible for inclusion if they assessed the effect of a non-surgical intervention on ankle joint dorsiflexion in healthy populations. Studies were quality rated using a standard quality assessment scale. Standardised mean differences (SMDs) and 95% confidence intervals (CIs) were calculated and results were pooled where study methods were homogenous. Results Twenty-three studies met eligibility criteria, with a total of 734 study participants. Results suggest that there is some evidence to support the efficacy of static stretching alone (SMDs: range 0.70 to 1.69) and static stretching in combination with ultrasound (SMDs: range 0.91 to 0.95), diathermy (SMD 1.12), diathermy and ice (SMD 1.16), heel raise exercises (SMDs: range 0.70 to 0.77), superficial moist heat (SMDs: range 0.65 to 0.84) and warm up (SMD 0.87) in improving ankle joint dorsiflexion ROM. Conclusions Some evidence exists to support the efficacy of stretching alone and stretching in combination with other therapies in increasing ankle joint ROM in healthy individuals. There is a paucity of quality evidence to support the efficacy of other non-surgical interventions, thus further research in this area is warranted. PMID:24225348

  14. Acute Effects of Two Massage Techniques on Ankle Joint Flexibility and Power of the Plantar Flexors

    PubMed Central

    McKechnie, Grant J.B.; Young, Warren B.; Behm, David G.

    2007-01-01

    The purpose of this study was to determine if three minutes of petrissage and tapotement forms of massage would influence plantar flexors’ flexibility, and muscle power. Nineteen participants were randomly subjected to three conditions (control and two massages) before performing two power tests. Prior to the intervention, subjects completed ankle joint flexibility assessments. The conditions were; (1) control, where subjects lay prone and had a therapist’s hands resting, (2) vigorous petrissage, and (3) tapotement applied at a rate of 4Hz; all on the triceps surae. Following completion of the intervention, subjects immediately completed a post- ankle joint flexibility test, followed by a drop-jump and concentric calf raise. The power measures were; concentric peak force, rate of force development, and drop-jump height / contact time. The data showed a significant increase (p < 0.05) in ankle joint angle on the right leg and a corresponding tendency on the left. No significant change was seen with the power measures. Results suggest that massage can increase plantar flexors’ flexibility without a change in power and thus may be an alternative to static stretching during an athletic warm-up. Key pointsThree minutes of petrissage and tapotement forms of massage increased ankle flexibility.Massage did not adversely affect jump power measures.Massage may be an effective alternative to static stretching as a component of a pre-event warm-up. PMID:24149484

  15. Examination of knee joint moments on the function of knee-ankle-foot orthoses during walking.

    PubMed

    Andrysek, Jan; Klejman, Susan; Kooy, John

    2013-08-01

    The goal of this study was to investigate clinically relevant biomechanical conditions relating to the setup and alignment of knee-ankle-foot orthoses and the influence of these conditions on knee extension moments and orthotic stance control during gait. Knee moments were collected using an instrumented gait laboratory and concurrently a load transducer embedded at the knee-ankle-foot orthosis knee joint of four individuals with poliomyelitis. We found that knee extension moments were not typically produced in late stance-phase of gait. Adding a dorsiflexion stop at the orthotic ankle significantly decreased the knee flexion moments in late stance-phase, while slightly flexing the knee in stance-phase had a variable effect. The findings suggest that where users of orthoses have problems initiating swing-phase flexion with stance control orthoses, an ankle dorsiflexion stop may be used to enhance function. Furthermore, the use of stance control knee joints that lock while under flexion may contribute to more inconsistent unlocking of the stance control orthosis during gait.

  16. Dynamic Evaluation of the Contact Characteristics and Three-Dimensional Motion for the Ankle Joint with Lateral Ligament Injuries

    NASA Astrophysics Data System (ADS)

    Kawakami, Kensaku; Omori, Go; Terashima, Shojiro; Sakamoto, Makoto; Hara, Toshiaki

    The purpose of this study was to clarify the dynamic changes in contact pressure distribution and three-dimensional ankle joint motion before and after lateral ligament injuries. Five fresh and frozen intact cadaveric ankles were examined. Each ankle was mounted on a specially designed frame that preserved five degrees of freedom motion. The direct linear transformation technique was used to measure the three-dimensional ankle motion, and a pressure-sensitive conductive rubber sensor was inserted into the talocrural joint space to determine the contact pressure distribution. The contact area on the talus for intact ankle moved anteriorly and laterally with increasing dorsiflexion. An area of high pressure was observed in the medial aspect of the articular surface after the ligament was cut. Supination significantly increased after a combined anterior talofibular ligament (ATF) and calcaneofibular ligament (CF) were cut in comparison with after only an ATF was cut, and no significant differences were observed in motional properties under each experimental condition.

  17. Modeling and simulating the neuromuscular mechanisms regulating ankle and knee joint stiffness during human locomotion

    PubMed Central

    Maculan, Marco; Pizzolato, Claudio; Reggiani, Monica; Farina, Dario

    2015-01-01

    This work presents an electrophysiologically and dynamically consistent musculoskeletal model to predict stiffness in the human ankle and knee joints as derived from the joints constituent biological tissues (i.e., the spanning musculotendon units). The modeling method we propose uses electromyography (EMG) recordings from 13 muscle groups to drive forward dynamic simulations of the human leg in five healthy subjects during overground walking and running. The EMG-driven musculoskeletal model estimates musculotendon and resulting joint stiffness that is consistent with experimental EMG data as well as with the experimental joint moments. This provides a framework that allows for the first time observing 1) the elastic interplay between the knee and ankle joints, 2) the individual muscle contribution to joint stiffness, and 3) the underlying co-contraction strategies. It provides a theoretical description of how stiffness modulates as a function of muscle activation, fiber contraction, and interacting tendon dynamics. Furthermore, it describes how this differs from currently available stiffness definitions, including quasi-stiffness and short-range stiffness. This work offers a theoretical and computational basis for describing and investigating the neuromuscular mechanisms underlying human locomotion. PMID:26245321

  18. Differences in injury pattern and prevalence of cartilage lesions in knee and ankle joints: a retrospective cohort study.

    PubMed

    Aurich, Matthias; Hofmann, Gunther O; Rolauffs, Bernd; Gras, Florian

    2014-10-27

    Osteoarthritis (OA) is more common in the knee compared to the ankle joint. This can not be explained exclusively by anatomical and biomechanical differences. The aim of this study is to analyze and compare the injury pattern (clinically) and the cartilage lesions (arthroscopically) of knee and ankle joints in a cohort of patients from the same catchment area. A retrospective study of the clinical data of 3122 patients (2139 outpatients and 983 inpatients) was performed, who were treated due to an injury of the knee and ankle joint. Statistical analysis was performed using SigmaStat 3.0 (SPSS Inc, Chicago, USA). There is a higher prevalence of injuries in the ankle as compared to the knee joint in this population from the same catchment area. In contrast, high-grade cartilage lesions are more prevalent in the knee, whereas low grade cartilage lesions are equally distributed between knee and ankle. From this data it can be concluded that the frequency of injuries and the injury pattern of knee versus ankle joints do not correlate with the severity of cartilage lesions and may therefore have no direct influence on the differential incidence of OA in those two joints.

  19. Safety profile of sural nerve in posterolateral approach to the ankle joint: MRI study.

    PubMed

    Ellapparadja, Pregash; Husami, Yaya; McLeod, Ian

    2014-05-01

    The posterolateral approach to ankle joint is well suited for ORIF of posterior malleolar fractures. There are no major neurovascular structures endangering this approach other than the sural nerve. The sural nerve is often used as an autologous peripheral nerve graft and provides sensation to the lateral aspect of the foot. The aim of this paper is to measure the precise distance of the sural nerve from surrounding soft tissue structures so as to enable safe placement of skin incision in posterolateral approach. This is a retrospective image review study involving 64 MRI scans. All measurements were made from Axial T1 slices. The key findings of the paper is the safety window for the sural nerve from the lateral border of tendoachilles (TA) is 7 mm, 1.3 cm and 2 cm at 3 cm above ankle joint, at the ankle joint and at the distal tip of fibula respectively. Our study demonstrates the close relationship of the nerve in relation to TA and fibula in terms of exact measurements. The safety margins established in this study should enable the surgeon in preventing endangerment of the sural nerve encountered in this approach. PMID:24158742

  20. Joint Loads in Marsupial Ankles Reflect Habitual Bipedalism versus Quadrupedalism

    PubMed Central

    Carlson, Kristian J.; Jashashvili, Tea; Houghton, Kimberley; Westaway, Michael C.; Patel, Biren A.

    2013-01-01

    Joint surfaces of limb bones are loaded in compression by reaction forces generated from body weight and musculotendon complexes bridging them. In general, joints of eutherian mammals have regions of high radiodensity subchondral bone that are better at resisting compressive forces than low radiodensity subchondral bone. Identifying similar form-function relationships between subchondral radiodensity distribution and joint load distribution within the marsupial postcranium, in addition to providing a richer understanding of marsupial functional morphology, can serve as a phylogenetic control in evaluating analogous relationships within eutherian mammals. Where commonalities are established across phylogenetic borders, unifying principles in mammalian physiology, morphology, and behavior can be identified. Here, we assess subchondral radiodensity patterns in distal tibiae of several marsupial taxa characterized by different habitual activities (e.g., locomotion). Computed tomography scanning, maximum intensity projection maps, and pixel counting were used to quantify radiodensity in 41 distal tibiae of bipedal (5 species), arboreal quadrupedal (4 species), and terrestrial quadrupedal (5 species) marsupials. Bipeds (Macropus and Wallabia) exhibit more expansive areas of high radiodensity in the distal tibia than arboreal (Dendrolagus, Phascolarctos, and Trichosurus) or terrestrial quadrupeds (Sarcophilus, Thylacinus, Lasiorhinus, and Vombatus), which may reflect the former carrying body weight only through the hind limbs. Arboreal quadrupeds exhibit smallest areas of high radiodensity, though they differ non-significantly from terrestrial quadrupeds. This could indicate slightly more compliant gaits by arboreal quadrupeds compared to terrestrial quadrupeds. The observed radiodensity patterns in marsupial tibiae, though their statistical differences disappear when controlling for phylogeny, corroborate previously documented patterns in primates and xenarthrans

  1. Joint loads in marsupial ankles reflect habitual bipedalism versus quadrupedalism.

    PubMed

    Carlson, Kristian J; Jashashvili, Tea; Houghton, Kimberley; Westaway, Michael C; Patel, Biren A

    2013-01-01

    Joint surfaces of limb bones are loaded in compression by reaction forces generated from body weight and musculotendon complexes bridging them. In general, joints of eutherian mammals have regions of high radiodensity subchondral bone that are better at resisting compressive forces than low radiodensity subchondral bone. Identifying similar form-function relationships between subchondral radiodensity distribution and joint load distribution within the marsupial postcranium, in addition to providing a richer understanding of marsupial functional morphology, can serve as a phylogenetic control in evaluating analogous relationships within eutherian mammals. Where commonalities are established across phylogenetic borders, unifying principles in mammalian physiology, morphology, and behavior can be identified. Here, we assess subchondral radiodensity patterns in distal tibiae of several marsupial taxa characterized by different habitual activities (e.g., locomotion). Computed tomography scanning, maximum intensity projection maps, and pixel counting were used to quantify radiodensity in 41 distal tibiae of bipedal (5 species), arboreal quadrupedal (4 species), and terrestrial quadrupedal (5 species) marsupials. Bipeds (Macropus and Wallabia) exhibit more expansive areas of high radiodensity in the distal tibia than arboreal (Dendrolagus, Phascolarctos, and Trichosurus) or terrestrial quadrupeds (Sarcophilus, Thylacinus, Lasiorhinus, and Vombatus), which may reflect the former carrying body weight only through the hind limbs. Arboreal quadrupeds exhibit smallest areas of high radiodensity, though they differ non-significantly from terrestrial quadrupeds. This could indicate slightly more compliant gaits by arboreal quadrupeds compared to terrestrial quadrupeds. The observed radiodensity patterns in marsupial tibiae, though their statistical differences disappear when controlling for phylogeny, corroborate previously documented patterns in primates and xenarthrans

  2. Inverse Dynamics Model for the Ankle Joint with Applications in Tibia Malleolus Fracture

    NASA Astrophysics Data System (ADS)

    Budescu, E.; Merticaru, E.; Chirazi, M.

    The paper presents a biomechanical model of the ankle joint, in order to determine the force and the torque of reaction into the articulation, through inverse dynamic analysis, in various stages of the gait. Thus, knowing the acceleration of the foot and the reaction force between foot and ground during the gait, determined by experimental measurement, there was calculated, for five different positions of the foot, the joint reaction forces, on the basis of dynamic balance equations. The values numerically determined were compared with the admissible forces appearing in the technical systems of osteosynthesis of tibia malleolus fracture, in order to emphasize the motion restrictions during bone healing.

  3. Consideration of equilibrium equations at the hip joint alongside those at the knee and ankle joints has mixed effects on knee joint response during gait.

    PubMed

    Adouni, M; Shirazi-Adl, A

    2013-02-01

    Accurate estimation of muscle forces during daily activities such as walking is critical for a reliable evaluation of loads on the knee joint. To evaluate knee joint muscle forces, the importance of the inclusion of the hip joint alongside the knee and ankle joints when treating the equilibrium equations remains yet unknown. An iterative kinematics-driven finite element model of the knee joint that accounts for the synergy between passive structures and active musculature is employed. The knee joint muscle forces and biomechanical response are predicted and compared with our earlier results that did not account for moment equilibrium equations at the hip joint. This study indicates that inclusion of the hip joint in the optimization along the knee and ankle joints only slightly (<10%) influences total forces in quadriceps, lateral hamstrings and medial hamstrings. As a consequence, even smaller differences are found in predicted ligament forces, contact forces/areas, and cartilage stresses/strains during the stance phase of gait. The distribution of total forces between the uni- and bi-articular muscle components in quadriceps and in lateral hamstrings; however, substantially alter at different stance phases.

  4. The Colorado Haemophilia Paediatric Joint Physical Examination Scale: normal values and interrater reliability.

    PubMed

    Hacker, M R; Funk, S M; Manco-Johnson, M J

    2007-01-01

    Persons with haemophilia often experience their first joint haemorrhage in early childhood. Recurrent bleeding into a joint may lead to significant morbidity, specifically haemophilic arthropathy. Early identification of the onset and progression of joint damage is critical to preserving joint structure and function. Physical examination is the most feasible approach to monitor joint health. Our group developed the Colorado Haemophilia Paediatric Joint Physical Examination Scale to identify earlier signs of joint degeneration and incorporate developmentally appropriate tasks for assessing joint function in young children. This study's objectives were to establish normal ranges for this scale and assess interrater reliability. The ankles, knees and elbows of 72 healthy boys aged 1 through 7 years were evaluated by a physical therapist to establish normal ranges. Exactly 10 boys in each age category from 2 to 7 years were evaluated by a second physical therapist to determine interrater reliability. The original scale was modified to account for the finding that mild angulation in the weight-bearing joints is developmentally normal. The interrater reliability of the scale ranged from fair to good, underscoring the need for physical therapists to have specific training in the orthopaedic assessment of very young children and the measurement error inherent in the goniometer. Modifications to axial alignment scoring will allow the scale to distinguish healthy joints from those suffering frequent haemarthroses. PMID:17212728

  5. The estimated mechanical advantage of the prosimian ankle joint musculature, and implications for locomotor adaptation.

    PubMed

    Goto, Ryosuke; Kumakura, Hiroo

    2013-05-01

    In this study we compared the power arm lengths and mechanical advantages attributed to 12 lower leg muscles across three prosimian species. The origins and insertions of the lower leg muscles in Garnett's galago, the ring-tailed lemur, and the slow loris were quantified and correlated with positional behaviour. The ankle joint of the galago has a speed-oriented mechanical system, in contrast to that of the slow loris, which exhibits more power-oriented mechanics. The lemur ankle joint exhibited intermediate power arm lengths and an intermediate mechanical advantage relative to the other primates. This result suggests that the mechanical differences in the ankle between the galago and the lemur, taxa that exhibit similar locomotory repertoires, reflect a difference in the kinematics and kinetics of leaping (i.e. generalised vs. specialised leapers). In contrast to leaping primates, lorises have developed a more power-oriented mechanical system as a foot adaptation for positional behaviours such as bridging or cantilevering in their arboreal habitat. PMID:23489408

  6. The estimated mechanical advantage of the prosimian ankle joint musculature, and implications for locomotor adaptation.

    PubMed

    Goto, Ryosuke; Kumakura, Hiroo

    2013-05-01

    In this study we compared the power arm lengths and mechanical advantages attributed to 12 lower leg muscles across three prosimian species. The origins and insertions of the lower leg muscles in Garnett's galago, the ring-tailed lemur, and the slow loris were quantified and correlated with positional behaviour. The ankle joint of the galago has a speed-oriented mechanical system, in contrast to that of the slow loris, which exhibits more power-oriented mechanics. The lemur ankle joint exhibited intermediate power arm lengths and an intermediate mechanical advantage relative to the other primates. This result suggests that the mechanical differences in the ankle between the galago and the lemur, taxa that exhibit similar locomotory repertoires, reflect a difference in the kinematics and kinetics of leaping (i.e. generalised vs. specialised leapers). In contrast to leaping primates, lorises have developed a more power-oriented mechanical system as a foot adaptation for positional behaviours such as bridging or cantilevering in their arboreal habitat.

  7. The Effects of a Lateral Wedge Insole on Knee and Ankle Joints During Slope Walking.

    PubMed

    Uto, Yuki; Maeda, Tetsuo; Kiyama, Ryoji; Kawada, Masayuki; Tokunaga, Ken; Ohwatashi, Akihiko; Fukudome, Kiyohiro; Ohshige, Tadasu; Yoshimoto, Yoichi; Yone, Kazunori

    2015-12-01

    The purpose of this study was to determine whether a lateral wedge insole reduces the external knee adduction moment during slope walking. Twenty young, healthy subjects participated in this study. Subjects walked up and down a slope using 2 different insoles: a control flat insole and a 7° lateral wedge insole. A three-dimensional motion analysis system and force plate were used to examine the knee adduction moment, the ankle valgus moment, and the moment arm of the ground reaction force to the knee joint center in the frontal plane. The lateral wedge insole significantly decreased the moment arm of the ground reaction force, resulting in a reduction of the knee adduction moment during slope walking, similar to level walking. The reduction ratio of knee adduction moment by the lateral wedge insole during the early stance of up-slope walking was larger than that of level walking. Conversely, the lateral wedge insole increased the ankle valgus moment during slope walking, especially during the early stance phase of up-slope walking. Clinicians should examine the utilization of a lateral wedge insole for knee osteoarthritis patients who perform inclined walking during daily activity, in consideration of the load on the ankle joint. PMID:26252560

  8. Effects of balance training by knee joint motions on muscle activity in adult men with functional ankle instability

    PubMed Central

    Nam, Seung-min; Kim, Won-bok; Yun, Chang-kyo

    2016-01-01

    [Purpose] This study examined the effects of balance training by applying knee joint movements on muscle activity in male adults with functional ankle instability. [Subjects and Methods] 28 adults with functional ankle instability, divided randomly into an experimental group, which performed balance training by applying knee joint movements for 20 minutes and ankle joint exercises for 10 minutes, and a control group, which performed ankle joint exercise for 30 minutes. Exercises were completed three times a week for 8 weeks. Electromyographic values of the tibialis anterior, peroneus longus, peroneus brevis, and the lateral gastrocnemius muscles were obtained to compare and analyze muscle activity before and after the experiments in each group. [Results] The experimental group had significant increases in muscle activity in the tibialis anterior, peroneus longus, and lateral gastrocnemius muscles, while muscle activity in the peroneus brevis increased without significance. The control group had significant increases in muscle activity in the tibialis anterior and peroneus longus, while muscle activity in the peroneus brevis and lateral gastrocnemius muscles increased without significance. [Conclusion] In conclusion, balance training by applying knee joint movements can be recommended as a treatment method for patients with functional ankle instability. PMID:27313386

  9. Foot and ankle joint kinematics in rheumatoid arthritis cannot only be explained by alteration in walking speed.

    PubMed

    Dubbeldam, R; Nene, A V; Buurke, J H; Groothuis-Oudshoorn, C G M; Baan, H; Drossaers-Bakker, K W; van de Laar, M A F J; Hermens, H

    2011-03-01

    Rheumatoid arthritis (RA) manifests itself in the foot and ankle of RA patients. The foot and ankle joint kinematics of these patients differ from that of healthy subjects. However, the factors that lead to these differences are not yet fully understood. The aim of this study was to analyse the effect of walking speed and the disease process on foot and ankle joint kinematics of RA subjects. Gait recordings of 23 RA and 14 age-matched healthy subjects were performed and their foot and ankle joint kinematics were analysed during the stance phase of the gait cycle. Stance phase characteristics of the group of RA subjects and of the group of healthy subjects were compared. The healthy subjects walked at 100% (Vc), 75% (V75) and 50% (V50) of their comfortable walking speed. In a multi-level linear model significant differences between the two groups due to the factors walking speed and the disease process were analysed. The ankle dorsi-flexion, medial arch and hallux abduction motion at single-stance and toe-off were only influenced by the walking speed. The hallux maximum flexion at toe-off and the midfoot supination at single-stance were influenced by both the walking speed and the disease process. The hindfoot eversion motion at single-stance was only influenced by the disease process. In conclusion, the reduction of walking speed of RA subjects compared to healthy subjects does not explain all of the observed foot and ankle kinematics differences.

  10. IINCIDENCE OF ANKLE SPRAINS IN SOCCER PLAYERS WITH JOINT HYPERMOBILITY SYNDROME

    PubMed Central

    Vieira, Rodrigo Barreiros; Bertolini, Fabricio Melo; Vieira, Tallys Campos; Aguiar, Rodrigo Manso; Pinheiro, Guilherme Baldez; Lasmar, Rodrigo Campos Pace

    2015-01-01

    Objective: Eighty-three soccer players aged between 14 and 19 years, in the basic category of a professional soccer club in the city of Belo Horizonte, were followed up during the 2009 season. Methods: A prospective observational cohort study was conducted, in which these soccer players were divided randomly into two groups. The first consisted of individuals with joint hypermobility syndrome (JHS), totaling 22 players, and the second was a control group with 61 players without this syndrome, determined through a physical examinati. Results: Both groups were studied with regard to incidence of ankle sprains. At the end of this period, the data were compiled and statistical analysis was performed. A total of 43 cases of ankle injury due to sprains were recorded, of which nine episodes were in players with JHS, thus making p = 0.106. The significance level was 5%. Conclusion: We were able to conclude that in our study there was insufficient evidence to assert that there is an association with increased incidence of ankle sprains among patients with JHS. PMID:27047888

  11. Mathematical models of passive motion at the human ankle joint by equivalent spatial parallel mechanisms.

    PubMed

    Di Gregorio, R; Parenti-Castelli, V; O'Connor, J J; Leardini, A

    2007-03-01

    The paper presents a theoretical model of the ankle joint, i.e. tibio-talar articulation, which shows how the articular surfaces and the ligaments, acting together as a mechanism, can control the passive kinematics of the joint. The authors had previously shown that, in virtually unloaded conditions, the ankle behaves as a single degree-of-freedom system, and that two ligament fibres remain nearly isometric throughout the flexion arc. Two different equivalent spatial parallel mechanisms together with corresponding kinematic models were formulated. These assumed isometricity of fibres within the calcaneal-fibular and tibio-calcaneal ligaments and rigidity of the articulating surfaces, taken as three sphere-plane contacts in one model, and as a single spherical pair in the other. Geometry parameters for the models were obtained from three specimens. Motion predictions compare quite well with the measured motion of the specimens. The differences are accounted for by the simplifications adopted to represent the complex anatomical structures, and might be reduced by future more realistic representations of the natural articular surfaces.

  12. Contractile and elastic ankle joint muscular properties in young and older adults.

    PubMed

    Hasson, Christopher J; Miller, Ross H; Caldwell, Graham E

    2011-01-01

    The purpose of this study was to investigate age-related differences in contractile and elastic properties of both dorsi- (DF) and plantarflexor (PF) muscles controlling the ankle joint in young and older adults. Experimental data were collected while twelve young and twelve older male and female participants performed maximal effort isometric and isovelocity contractions on a dynamometer. Equations were fit to the data to give torque-angle (Tθ) and torque-angular velocity (Tω) relations. Muscle series-elasticity was measured during ramped dynamometer contractions using ultrasonography to measure aponeurosis extension as a function of torque; second order polynomials were used to characterize the torque-extension (TΔL) relation. The results showed no age differences in DF maximal torque and none for female PF; however, older males had smaller maximal PF torques compared to young males. In both muscle groups and genders, older adults had decreased concentric force capabilities. Both DF and PF TΔL relations were more nonlinear in the older adults. Older PF, but not DF muscles, were stiffer compared to young. A simple antagonism model suggested age-related differences in Tθ and Tω relations would be magnified if antagonistic torque contributions were included. This assessment of static, dynamic, and elastic joint properties affords a comprehensive view of age-related modifications in muscle function. Although many clinical studies use maximal isometric strength as a marker of functional ability, the results demonstrate that there are also significant age-related modifications in ankle muscle dynamic and elastic properties.

  13. Ankle impingement.

    PubMed

    Lavery, Kyle P; McHale, Kevin J; Rossy, William H; Theodore, George

    2016-01-01

    Ankle impingement is a syndrome that encompasses a wide range of anterior and posterior joint pathology involving both osseous and soft tissue abnormalities. In this review, the etiology, pathoanatomy, diagnostic workup, and treatment options for both anterior and posterior ankle impingement syndromes are discussed. PMID:27608626

  14. Ankle impingement.

    PubMed

    Lavery, Kyle P; McHale, Kevin J; Rossy, William H; Theodore, George

    2016-09-09

    Ankle impingement is a syndrome that encompasses a wide range of anterior and posterior joint pathology involving both osseous and soft tissue abnormalities. In this review, the etiology, pathoanatomy, diagnostic workup, and treatment options for both anterior and posterior ankle impingement syndromes are discussed.

  15. Inverted Pendulum Standing Apparatus for Investigating Closed-Loop Control of Ankle Joint Muscle Contractions during Functional Electrical Stimulation

    PubMed Central

    Tan, John F.; Masani, Kei; Vette, Albert H.; Zariffa, José; Robinson, Mark; Lynch, Cheryl; Popovic, Milos R.

    2014-01-01

    The restoration of arm-free standing in individuals with paraplegia can be facilitated via functional electrical stimulation (FES). In developing adequate control strategies for FES systems, it remains challenging to test the performance of a particular control scheme on human subjects. In this study, we propose a testing platform for developing effective control strategies for a closed-loop FES system for standing. The Inverted Pendulum Standing Apparatus (IPSA) is a mechanical inverted pendulum, whose angular position is determined by the subject's ankle joint angle as controlled by the FES system while having the subject's body fixed in a standing frame. This approach provides a setup that is safe, prevents falling, and enables a research and design team to rigorously test various closed-loop controlled FES systems applied to the ankle joints. To demonstrate the feasibility of using the IPSA, we conducted a case series that employed the device for studying FES closed-loop controllers for regulating ankle joint kinematics during standing. The utilized FES system stimulated, in able-bodied volunteers, the plantarflexors as they prevent toppling during standing. Four different conditions were compared, and we were able to show unique performance of each condition using the IPSA. We concluded that the IPSA is a useful tool for developing and testing closed-loop controlled FES systems for regulating ankle joint position during standing. PMID:27350992

  16. Inverted Pendulum Standing Apparatus for Investigating Closed-Loop Control of Ankle Joint Muscle Contractions during Functional Electrical Stimulation.

    PubMed

    Tan, John F; Masani, Kei; Vette, Albert H; Zariffa, José; Robinson, Mark; Lynch, Cheryl; Popovic, Milos R

    2014-01-01

    The restoration of arm-free standing in individuals with paraplegia can be facilitated via functional electrical stimulation (FES). In developing adequate control strategies for FES systems, it remains challenging to test the performance of a particular control scheme on human subjects. In this study, we propose a testing platform for developing effective control strategies for a closed-loop FES system for standing. The Inverted Pendulum Standing Apparatus (IPSA) is a mechanical inverted pendulum, whose angular position is determined by the subject's ankle joint angle as controlled by the FES system while having the subject's body fixed in a standing frame. This approach provides a setup that is safe, prevents falling, and enables a research and design team to rigorously test various closed-loop controlled FES systems applied to the ankle joints. To demonstrate the feasibility of using the IPSA, we conducted a case series that employed the device for studying FES closed-loop controllers for regulating ankle joint kinematics during standing. The utilized FES system stimulated, in able-bodied volunteers, the plantarflexors as they prevent toppling during standing. Four different conditions were compared, and we were able to show unique performance of each condition using the IPSA. We concluded that the IPSA is a useful tool for developing and testing closed-loop controlled FES systems for regulating ankle joint position during standing.

  17. Therapeutic Experience on Stance Control Knee-Ankle-Foot Orthosis With Electromagnetically Controlled Knee Joint System in Poliomyelitis

    PubMed Central

    Kim, Jung-Hwan; Ji, Sang-Goo; Jung, Kang-Jae

    2016-01-01

    A 54-year-old man with poliomyelitis had been using a conventional, passive knee-ankle-foot orthosis (KAFO) with a drop ring lock knee joint for about 40 years. A stance control KAFO (SCKAFO) with an electromagnetically controlled (E-MAG) knee joint system was prescribed. To correct his gait pattern, he also underwent rehabilitation therapy, which included muscle re-education, neuromuscular electrical stimulation, strengthening exercises for the lower extremities, and balance training twice a week for about 4 months. Both before and after rehabilitation, we conducted a gait analysis and assessed the physiological cost index in energy expended during walking in a locked-knee state and while he wore a SCKAFO with E-MAG. When compared with the pre-rehabilitation data, the velocity, step length, stride length, and knee kinematic data were improved after rehabilitation. Although the SCKAFO with E-MAG system facilitated the control of knee motion during ambulation, appropriate rehabilitative therapy was also needed to achieve a normal gait pattern. PMID:27152288

  18. Kinesio-Taping Application and Corticospinal Excitability at the Ankle Joint

    PubMed Central

    Tremblay, Francois; Karam, Siobhan

    2015-01-01

    Context Physiotherapists and athletic trainers often use Kinesio Taping (KT) to prevent and treat musculoskeletal injuries in athletes, yet evidence about its effects on neuromuscular performance is conflicting. Objective To investigate the influence of a KT application directed at the ankle joint on measures of corticospinal excitability with transcranial magnetic stimulation. Design Controlled laboratory study. Setting Research laboratory. Patients or Other Participants Twelve healthy young women (age = 23.1 ± 1.9 years; range, 19–26 years). Intervention(s) Participants were tested under no-tape and KT conditions according to a random sequence order. The KT was applied to the skin overlying the dorsiflexor and plantar-flexor muscles of the ankle. Main Outcome Measure(s) We assessed changes in the amplitude of motor-evoked potentials elicited at rest and during movement and changes in the silent period and background muscle activity during movement. Results Taping conditions had no effect on motor-evoked potential amplitude at rest or during movement or on the silent-period duration and background muscle activity. Conclusions Our results concur with other recent reports, showing KT applications have little influence at the neuromuscular level. Alterations in sensory feedback ascribed to elastic taping are likely insufficient to modulate corticospinal excitability in a functionally meaningful manner. PMID:26090708

  19. A Patient-Specific Foot Model for the Estimate of Ankle Joint Forces in Patients with Juvenile Idiopathic Arthritis.

    PubMed

    Prinold, Joe A I; Mazzà, Claudia; Di Marco, Roberto; Hannah, Iain; Malattia, Clara; Magni-Manzoni, Silvia; Petrarca, Maurizio; Ronchetti, Anna B; Tanturri de Horatio, Laura; van Dijkhuizen, E H Pieter; Wesarg, Stefan; Viceconti, Marco

    2016-01-01

    Juvenile idiopathic arthritis (JIA) is the leading cause of childhood disability from a musculoskeletal disorder. It generally affects large joints such as the knee and the ankle, often causing structural damage. Different factors contribute to the damage onset, including altered joint loading and other mechanical factors, associated with pain and inflammation. The prediction of patients' joint loading can hence be a valuable tool in understanding the disease mechanisms involved in structural damage progression. A number of lower-limb musculoskeletal models have been proposed to analyse the hip and knee joints, but juvenile models of the foot are still lacking. This paper presents a modelling pipeline that allows the creation of juvenile patient-specific models starting from lower limb kinematics and foot and ankle MRI data. This pipeline has been applied to data from three children with JIA and the importance of patient-specific parameters and modelling assumptions has been tested in a sensitivity analysis focused on the variation of the joint reaction forces. This analysis highlighted the criticality of patient-specific definition of the ankle joint axes and location of the Achilles tendon insertions. Patient-specific detection of the Tibialis Anterior, Tibialis Posterior, and Peroneus Longus origins and insertions were also shown to be important.

  20. A Patient-Specific Foot Model for the Estimate of Ankle Joint Forces in Patients with Juvenile Idiopathic Arthritis.

    PubMed

    Prinold, Joe A I; Mazzà, Claudia; Di Marco, Roberto; Hannah, Iain; Malattia, Clara; Magni-Manzoni, Silvia; Petrarca, Maurizio; Ronchetti, Anna B; Tanturri de Horatio, Laura; van Dijkhuizen, E H Pieter; Wesarg, Stefan; Viceconti, Marco

    2016-01-01

    Juvenile idiopathic arthritis (JIA) is the leading cause of childhood disability from a musculoskeletal disorder. It generally affects large joints such as the knee and the ankle, often causing structural damage. Different factors contribute to the damage onset, including altered joint loading and other mechanical factors, associated with pain and inflammation. The prediction of patients' joint loading can hence be a valuable tool in understanding the disease mechanisms involved in structural damage progression. A number of lower-limb musculoskeletal models have been proposed to analyse the hip and knee joints, but juvenile models of the foot are still lacking. This paper presents a modelling pipeline that allows the creation of juvenile patient-specific models starting from lower limb kinematics and foot and ankle MRI data. This pipeline has been applied to data from three children with JIA and the importance of patient-specific parameters and modelling assumptions has been tested in a sensitivity analysis focused on the variation of the joint reaction forces. This analysis highlighted the criticality of patient-specific definition of the ankle joint axes and location of the Achilles tendon insertions. Patient-specific detection of the Tibialis Anterior, Tibialis Posterior, and Peroneus Longus origins and insertions were also shown to be important. PMID:26374518

  1. Contractile and Elastic Ankle Joint Muscular Properties in Young and Older Adults

    PubMed Central

    Hasson, Christopher J.; Miller, Ross H.; Caldwell, Graham E.

    2011-01-01

    The purpose of this study was to investigate age-related differences in contractile and elastic properties of both dorsi- (DF) and plantarflexor (PF) muscles controlling the ankle joint in young and older adults. Experimental data were collected while twelve young and twelve older male and female participants performed maximal effort isometric and isovelocity contractions on a dynamometer. Equations were fit to the data to give torque-angle (Tθ) and torque-angular velocity (Tω) relations. Muscle series-elasticity was measured during ramped dynamometer contractions using ultrasonography to measure aponeurosis extension as a function of torque; second order polynomials were used to characterize the torque-extension (TΔL) relation. The results showed no age differences in DF maximal torque and none for female PF; however, older males had smaller maximal PF torques compared to young males. In both muscle groups and genders, older adults had decreased concentric force capabilities. Both DF and PF TΔL relations were more nonlinear in the older adults. Older PF, but not DF muscles, were stiffer compared to young. A simple antagonism model suggested age-related differences in Tθ and Tω relations would be magnified if antagonistic torque contributions were included. This assessment of static, dynamic, and elastic joint properties affords a comprehensive view of age-related modifications in muscle function. Although many clinical studies use maximal isometric strength as a marker of functional ability, the results demonstrate that there are also significant age-related modifications in ankle muscle dynamic and elastic properties. PMID:21264315

  2. The effects of ankle joint muscle strengthening and proprioceptive exercise programs accompanied by functional electrical stimulation on stroke patients’ balance

    PubMed Central

    Kim, Kyunghoon; Lee, Sukmin; Kim, Donghoon; Kim, Kyou Sik

    2015-01-01

    [Purpose] The purpose of the present study was to examine the effects of ankle joint muscle strengthening and proprioceptive exercises accompanied by functional electrical stimulation on stroke patients’ balance ability. [Methods] For six weeks beginning in April 2015, 22 stroke patients receiving physical therapy at K Hospital located in Gyeonggi-do were divided into a functional electrical stimulation (FES), ankle proprioceptive exercise and ankle joint muscle strengthening exercise group (FPS group) of 11 patients and an FES and stretching exercise group (FS group) of 11 patients. The stimulation and exercises were conducted for 30 min per day, five days per week for six weeks. Balance ability was measured using a BioRescue and the Berg balance scale, functional reach test, and the timed up-and-go test were also used as clinical evaluation indices. Repeated measures ANOVA was conducted to examine differences between before the exercises and at three and six weeks after beginning the exercises within each group, and the amounts of change between the two groups were compared. [Results] In the comparison within each group, both groups showed significant differences between before and after the experiment in all the tests and comparison between the groups showed that greater improvement was seen in all values in the FPS group. [Conclusion] In the present study, implementing FES and stretching exercises plus ankle joint muscle strengthening and proprioceptive exercises was more effective at improving stroke patients balance ability than implementing only FES and stretching exercises. PMID:26504337

  3. The effects of ankle joint muscle strengthening and proprioceptive exercise programs accompanied by functional electrical stimulation on stroke patients' balance.

    PubMed

    Kim, Kyunghoon; Lee, Sukmin; Kim, Donghoon; Kim, Kyou Sik

    2015-09-01

    [Purpose] The purpose of the present study was to examine the effects of ankle joint muscle strengthening and proprioceptive exercises accompanied by functional electrical stimulation on stroke patients' balance ability. [Methods] For six weeks beginning in April 2015, 22 stroke patients receiving physical therapy at K Hospital located in Gyeonggi-do were divided into a functional electrical stimulation (FES), ankle proprioceptive exercise and ankle joint muscle strengthening exercise group (FPS group) of 11 patients and an FES and stretching exercise group (FS group) of 11 patients. The stimulation and exercises were conducted for 30 min per day, five days per week for six weeks. Balance ability was measured using a BioRescue and the Berg balance scale, functional reach test, and the timed up-and-go test were also used as clinical evaluation indices. Repeated measures ANOVA was conducted to examine differences between before the exercises and at three and six weeks after beginning the exercises within each group, and the amounts of change between the two groups were compared. [Results] In the comparison within each group, both groups showed significant differences between before and after the experiment in all the tests and comparison between the groups showed that greater improvement was seen in all values in the FPS group. [Conclusion] In the present study, implementing FES and stretching exercises plus ankle joint muscle strengthening and proprioceptive exercises was more effective at improving stroke patients balance ability than implementing only FES and stretching exercises.

  4. Mobility of the ankle joint: recording of rotatory movements in the talocrural joint in vitro with and without the lateral collateral ligaments of the ankle.

    PubMed

    Rasmussen, O; Tovborg-Jensen, I

    1982-02-01

    A method for graphic recording of rotatory movements in osteoligamentous ankle preparations is described. By this method it is possible to record characteristic mobility patterns in two planes at the same time. The ankle is affected by a known torque, so that the individual mobility patterns are reproducible with unchanged condition of the ligaments. Six amputated legs were investigated in the sagittal and horizontal planes and another six in the sagittal and frontal planes. Mobility patterns were recorded with intact ligaments and after successive cutting of the lateral collateral ligaments of the ankle in the anteroposterior direction. In the sagittal plane increased dorsiflexion was observed after total cutting of the lateral ligaments, while plantar flexion remained unchanged. In the horizontal plane the internal rotation of the talus increased in step with increasing injury to the ligament, particularly when the ankle was plantar flexed. When all collateral ligaments had been cut, an increase in external rotation occurred, especially in dorsiflexion. In the frontal plane the talar tilt increased gradually with increasing injury to the ligaments. Talar tilt was at a maximum in the neutral position of the ankle or in plantar flexion. After total severing of the collateral ligaments, however, talar tilt was most marked in dorsiflexion of the ankle.

  5. Arthroscopic Ankle Arthrodesis.

    PubMed

    Hutchinson, Byron

    2016-10-01

    Arthroscopic ankle arthrodesis is a cost-effective option for many patients with posttraumatic arthritis of the ankle joint. Rehabilitation is generally quicker than conventional open techniques, and rates of fusion are comparable or better than traditional open techniques. Unless the arthroscopic surgeon has considerable experience, the best results are seen in patients with very little deformity in the ankle joint. PMID:27599442

  6. Human soleus muscle architecture at different ankle joint angles from magnetic resonance diffusion tensor imaging

    PubMed Central

    Sinha, Usha; Hodgson, John A.; Edgerton, Reggie V.

    2011-01-01

    The orientation of muscle fibers influences the physiological cross-sectional area, the relationship between fiber shortening and aponeurosis shear, and the total force produced by the muscle. Such architectural parameters are challenging to determine particularly in vivo in multicompartment structures such as the human soleus with a complex arrangement of muscle fibers. The objective of this study was to map the fiber architecture of the human soleus in vivo at rest in both neutral and plantarflexed ankle positions using an MRI-based method of diffusion tensor imaging (DTI). Six subjects were imaged at 3 Tesla with the foot at rest in the two ankle positions. Eigenvalues, fractional anisotropy (FA), and eigenvector orientations of fibers in the different soleus subcompartments were evaluated after denoising of the diffusion tensor. The fiber architecture from DTI was similar to earlier studies based on a 3D fiber model from cadavers. The three eigenvalues of the diffusion tensor increased by ∼14% on increasing the joint plantarflexion angle in all of the soleus subcompartments, whereas FA showed a trend to decrease in the posterior and marginal soleus and to increase in the anterior soleus. The angle change in the lead eigenvector between the two foot positions was significant: ∼41° for the posterior soleus and ∼48° for the anterior soleus. Fibers tracked from the subcompartments support these changes seen in the eigenvector orientations. DTI-derived, subject-specific, muscle morphological data could potentially be used to model a more complete description of muscle performance and changes from disease. PMID:21164150

  7. Movement within foot and ankle joint in children with spastic cerebral palsy: a 3-dimensional ultrasound analysis of medial gastrocnemius length with correction for effects of foot deformation

    PubMed Central

    2013-01-01

    Background In spastic cerebral palsy (SCP), a limited range of motion of the foot (ROM), limits gait and other activities. Assessment of this limitation of ROM and knowledge of active mechanisms is of crucial importance for clinical treatment. Methods For a comparison between spastic cerebral palsy (SCP) children and typically developing children (TD), medial gastrocnemius muscle-tendon complex length was assessed using 3-D ultrasound imaging techniques, while exerting externally standardized moments via a hand-held dynamometer. Exemplary X-ray imaging of ankle and foot was used to confirm possible TD-SCP differences in foot deformation. Results SCP and TD did not differ in normalized level of excitation (EMG) of muscles studied. For given moments exerted in SCP, foot plate angles were all more towards plantar flexion than in TD. However, foot plate angle proved to be an invalid estimator of talocrural joint angle, since at equal foot plate angles, GM muscle-tendon complex was shorter in SCP (corresponding to an equivalent of 1 cm). A substantial difference remained even after normalizing for individual differences in tibia length. X-ray imaging of ankle and foot of one SCP child and two typically developed adults, confirmed that in SCP that of total footplate angle changes (0-4 Nm: 15°), the contribution of foot deformation to changes in foot plate angle (8) were as big as the contribution of dorsal flexion at the talocrural joint (7°). In typically developed individuals there were relatively smaller contributions (10 -11%) by foot deformation to changes in foot plate angle, indicating that the contribution of talocrural angle changes was most important. Using a new estimate for position at the talocrural joint (the difference between GM muscle–tendon complex length and tibia length, GM relative length) removed this effect, thus allowing more fair comparison of SCP and TD data. On the basis of analysis of foot plate angle and GM relative length as a function

  8. Effect of passive stretching and jogging on the series elastic muscle stiffness and range of motion of the ankle joint

    PubMed Central

    McNair, Peter J; Stanley, Stephen N

    1996-01-01

    Objective To determine the effect of stretching and jogging on the series elastic muscle stiffness of the plantar flexors and on the range of dorsiflexion at the ankle joint. Methods 24 healthy subjects participated in this study. Each subject undertook all of the following protocols, in random order: (1) stretching protocol: five 30 s static stretches with 30 s rest between stretches; (2) aerobic jogging protocol: subjects ran on a treadmill for 10 min at 60% of their maximum age predicted heart rate; (3) combined protocol: subjects ran first and then stretched. A damped oscillation technique was used to measure the series elastic stiffness of the plantar flexors. Dorsiflexion of the ankle was assessed with a weights and pulley system that moved the ankle joint from a neutral position into dorsiflexion passively. Electromyography was used to monitor the activity of the plantar and dorsiflexors during these procedures. The statistical analysis of these data involved an analysis of covariance Results For decreasing series elastic muscle stiffness running was more effective than stretching (P<0.05). In contrast, the results for range of motion showed that the combination protocol and the stretching only protocol were more effective than the running only protocol (P < 0.05) for increasing dorsiflexion range of motion at the ankle. Conclusions Both jogging and static stretching exercises appear to be beneficial to individuals participating in sporting activities. ImagesFigure 2Figure 3Figure 4Figure 5Figure 6 PMID:9015593

  9. A computed tomography evaluation of two hundred normal ankles, to ascertain what anatomical landmarks to use when compressing or placing an ankle syndesmosis screw.

    PubMed

    Kennedy, M T; Carmody, O; Leong, S; Kennedy, C; Dolan, M

    2014-12-01

    Classical AO teaching recommends that a syndesmosis screw should be inserted at 25-30 degrees to the coronal plane of the ankle. Accurately judging the 25/30 degree angle can be difficult, resulting in poor operative reduction of syndesmosis injuries. The CT scans of 200 normal ankles were retrospectively examined. The centroid of the fibula and tibia in the axial plane 15mm proximal to the talar dome was calculated. A force vector between the centroid of the fibula and the tibia in the axial plane should not displace the fibula relative to the tibia when surfaces are parallel. Therefore, a line connecting the two centroids was postulated to be the ideal syndesmosis line. This line was shown to pass through the fibula within 2.5mm of the lateral cortical apex of the fibula and the anterior half of the medial malleolus in 100% of the ankles studied. The results support the concept that in the operatively reduced syndesmosis, the anterior half of the medial malleolus can be used as a reliable guide for aiming the syndesmosis drill hole, provided that the fibular entry point is at/or adjacent to the lateral fibular apex. The screw should also remain parallel to the tibial plafond in the coronal plane. PMID:25127526

  10. Changes of Achilles tendon properties via 12-week PNF based robotic rehabilitation of ankle joints with spasticity and/or contracture.

    PubMed

    Zhou, Zhihao; Zhou, Yuan; Wang, Ninghua; Gao, Fan; Wang, Long; Wei, Kunlin; Wang, Qining

    2014-01-01

    Ankle joint with spasticity and/or contracture can severely affect mobility and independence of stroke survivors. Due to that, the Achilles tendon(AT) is affected. In this paper, we aim to study changes of AT properties via proprioceptive neuromuscular facilitation (PNF) treatment. A robotic ankle-foot rehabilitation system has been proposed, which consists of a robotic ankle-foot platform and a graphic user interface. In this pilot study, two post-stroke patients participated and carried out a 12-week PNF treatment with the robotic system. The treatment is evaluated quantitatively in AT properties. The evaluation shows that after the PNF treatment, the average decrease of AT length is 4.1 mm (6.5%) and the recovery ratio is 30.4%, while the thickness has no change. The results indicate that the PNF based robotic rehabilitation for ankle joints with spasticity and/or contracture is effective to improve the ankle spasticity/contracture.

  11. The effects of ankle joint strategy exercises with and without visual feedback on the dynamic balance of stroke patients

    PubMed Central

    Jeon, Si-Nae; Choi, Jung-Hyun

    2015-01-01

    [Purpose] The aim of this study was to examine the effects of visual feedback training on the balance of stroke patients performing ankle joint strategy exercises. [Subjects and Methods] In this study, 26 stroke patients were randomly and equally assigned to a visual feedback group (VFG) and a visual disuse group (VDG). They performed ankle joint strategy exercises for 30 minutes, three times per week for six weeks. The patients’ balance ability was measured before and after the exercises to compare the effects of visual feedback. To assess balance ability, the limits of stability (LOS) and the distance the center of pressure (CoP) moved were measured using a BT4 portable force platform. The Berg balance scale (BBS) and the timed up and go (TUG) test were also used to assess balance before and after the exercises. [Results] Changes in LOS were significant in the anterior, posterior, left, and right directions in each group, and the interactions between the two groups were significant in the posterior, left, and right directions. The changes in TUG and BBS results between pre-test and the post-test were statistically significant in the two groups, and also between the groups. [Conclusion] Visual feedback training had a positive effect on balance when ankle joint strategy exercises were performed by stroke patients to improve balance. PMID:26355721

  12. Effect of isotonic and isokinetic exercise on muscle activity and balance of the ankle joint

    PubMed Central

    Kim, Mi-Kyoung; Yoo, Kyung-Tae

    2015-01-01

    [Purpose] This study was performed to examine how the balance of lower limbs and the muscle activities of the tibialis anterior (TA), the medial gastrocnemius (GCM), and the peroneus longus (PL) are influenced by isotonic and isokinetic exercise of the ankle joint. [Subjects] The subjects of this study were healthy adults (n=20), and they were divided into two groups (isotonic=10, isokinetic=10). [Methods] Isotonic group performed 3 sets of 10 contractions at 50% of MVIC and Isokinetic group performed 3 sets of 60°/sec. Muscle activity was measured by EMG and balance was measured by one-leg standing test. [Results] For muscle activity, a main effect of group was found in the non-dominant TA, and the dominant TA, GCM and PL. For balance, a main effect of time was found in both groups for the sway area measured support was provided by the non-dominant side. [Conclusion] In terms of muscle activity, the two groups showed a significant difference, and the isokinetic group showed higher muscle activities. In terms of balance, there was a significant difference between the pre-test and the post-test. The results of this study may help in the selection of exercises for physical therapy, because they show that muscle activity and balance vary according to the type of exercise. PMID:25729181

  13. ANKLE JOINT CONTROL DURING SINGLE-LEGGED BALANCE USING COMMON BALANCE TRAINING DEVICES – IMPLICATIONS FOR REHABILITATION STRATEGIES

    PubMed Central

    Strøm, Mark; Thorborg, Kristian; Bandholm, Thomas; Tang, Lars; Zebis, Mette; Nielsen, Kristian

    2016-01-01

    ABSTRACT Background A lateral ankle sprain is the most prevalent musculoskeletal injury in sports. Exercises that aim to improve balance are a standard part of the ankle rehabilitation process. In an optimal progression model for ankle rehabilitation and prevention of future ankle sprains, it is important to characterize different balance exercises based on level of difficulty and sensori-motor training stimulus. Purpose The purpose of this study was to investigate frontal-plane ankle kinematics and associated peroneal muscle activity during single-legged balance on stable surface (floor) and three commonly used balance devices (Airex®, BOSU® Ball and wobble board). Design Descriptive exploratory laboratory study. Methods Nineteen healthy subjects performed single-legged balance with eyes open on an Airex® mat, BOSU® Ball, wobble board, and floor (reference condition). Ankle kinematics were measured using reflective markers and 3-dimensional recordings and expressed as inversion-eversion range of motion variability, peak velocity of inversion and number of inversion-eversion direction changes. Peroneus longus EMG activity was averaged and normalized to maximal activity during maximum voluntary contraction (MVC), and in addition amplitude probability distribution function (APDF) between 90 and 10% was calculated as a measure of muscle activation variability. Results Balancing on BOSU® Ball and wobble board generally resulted in increased ankle kinematic and muscle activity variables, compared to the other surfaces. BOSU® Ball was the most challenging in terms of inversion-eversion variability while wobble board was associated with a higher number of inversion-eversion direction changes. No differences in average muscle activation level were found between these two surfaces, but the BOSU® Ball did show a more variable activation pattern in terms of APDF. Conclusion The results showed large kinematic variability among different balance training devices and

  14. An EMG-Controlled SMA Device for the Rehabilitation of the Ankle Joint in Post-Acute Stroke

    NASA Astrophysics Data System (ADS)

    Pittaccio, S.; Viscuso, S.

    2011-07-01

    The capacity of flexing one's ankle is an indispensible segment of gait re-learning, as imbalance, wrong compensatory use of other joints and risk of falling may depend on the so-called drop-foot. The rehabilitation of ankle dorsiflexion may be achieved through active exercising of the relevant musculature (especially tibialis anterior, TA). This can be troublesome for patients affected by weakness and flaccid paresis. Thus, as needs evolve during patient's improvements, a therapeutic device should be able to guide and sustain gradual recovery by providing commensurate aid. This includes exploiting even initial attempts at voluntary motion and turns those into effective workout. An active orthosis powered by two rotary actuators containing NiTi wire was designed to obtain ankle dorsiflexion. A computer routine that analyzes the electromyographic (sEMG) signal from TA muscle is used to control the orthosis and trigger its activation. The software also provides instructions and feed-back for the patient. Tests on the orthosis proved that it can produce strokes up to 36° against resisting torques exceeding 180 Ncm. Three healthy subjects were able to control the orthosis by modulating their TA sEMG activity. The movement produced in the preliminary tests is interesting for lower limb rehabilitation, and will be further improved by optimizing body-orthosis interface. It is hoped that this device will enhance early rehabilitation and recovery of ankle mobility in stroke patients.

  15. The Effect of Velocity of Joint Mobilization on Corticospinal Excitability in Individuals With a History of Ankle Sprain.

    PubMed

    Fisher, Beth E; Piraino, Andrew; Lee, Ya-Yun; Smith, Jo Armour; Johnson, Sean; Davenport, Todd E; Kulig, Kornelia

    2016-07-01

    Study Design Controlled laboratory study. Background Joint mobilization and manipulation decrease pain and improve patient function. Yet, the processes underlying these changes are not well understood. Measures of corticospinal excitability provide insight into potential mechanisms mediated by the central nervous system. Objectives To investigate the differential effects of joint mobilization and manipulation at the talocrural joint on corticospinal excitability in individuals with resolved symptoms following ankle sprain. Methods Twenty-seven participants with a history of ankle sprain were randomly assigned to the control, joint mobilization, or thrust manipulation group. The motor-evoked potential (MEP) and cortical silent period (CSP) of the tibialis anterior and gastrocnemius were obtained with transcranial magnetic stimulation at rest and during active contraction of the tibialis anterior. The slopes of MEP/CSP input/output curves and the maximal MEP/CSP values were calculated to indicate corticospinal excitability. Behavioral measures, including ankle dorsiflexion and dynamic balance, were evaluated. Results A repeated-measures analysis of variance of the MEP slope showed a significant group-by-time interaction for the tibialis anterior at rest (P = .002) and during active contraction (P = .042). After intervention, the thrust manipulation group had an increase in corticospinal excitability, while the corticospinal excitability decreased in the mobilization group. The thrust manipulation group, but not other groups, also demonstrated a significant increase in the maximal MEP amplitude of the tibialis anterior after intervention. Conclusion The findings suggest that joint manipulation and mobilization have different effects on corticospinal excitability. The increased corticospinal excitability following thrust manipulation may provide a window for physical therapists to optimize muscle recruitment and subsequently movement. The trial was registered at

  16. Effects of ankle joint mobilization with movement and weight-bearing exercise on knee strength, ankle range of motion, and gait velocity in patients with stroke: a pilot study.

    PubMed

    An, Chang-Man; Won, Jong-Im

    2016-01-01

    [Purpose] The purpose of this study was to investigate the effects of ankle joint mobilization with movement on knee strength, ankle range of motion, and gait velocity, compared with weight-bearing exercise in stroke patients. [Subjects and Methods] Thirty subjects with chronic stroke were divided into three groups: MWM (n = 12), WBE (n = 8), and control (n = 10). All groups attended physical therapy sessions 3 times a week for 5 weeks. Subjects in the MWM group performed mobilization with movement exercises, whilst participants in the WBE group performed weight-bearing exercises. Knee peak torque, ankle range of motion, and spatiotemporal gait parameters were evaluated before and after the interventions. [Results] Knee extensor peak torque increased significantly in both MWM and WBE groups. However, only the MWM group showed significant improvement in passive and active ankle range of motion and gait velocity, among the three groups. [Conclusion] Ankle joint mobilization with movement intervention is more effective than simple weight-bearing intervention in improving gait speed in stroke patients with limited ankle motion.

  17. Kinetic Relationships between the Hip and Ankle Joints during Gait in Children with Cerebral Palsy: A Pilot Study.

    PubMed

    Ishihara, Misako; Higuchi, Yumi

    2014-05-01

    [Purpose] The purpose of this study was to evaluate kinetic relationships between the ankle and hip joints during gait, in the late stance, in children with spastic cerebral palsy (CP). [Subjects] The subjects were 3 ambulant children with spastic hemiplegic CP (aged 10, 13, and 14: CP group) and 3 typically developing children with the same ages (control). [Methods] A three-dimensional gait analysis including force data was performed to compare the peak moment, power, and ankle/hip power ratio between the hemiplegic (uninvolved and hemiplegic) and the control groups. In the statistical analysis, mean values from 5 gait cycles for each of 3 conditions (uninvolved, hemiplegic and control) were used. The three conditions were compared by performing a Kruskal-Wallis test and Steel-Dwass multiple comparisons. [Results] The peak moments of ankle plantar flexors in the 10-year-old case, were significantly lower on the uninvolved and hemiplegic sides compared with the control group, respectively. The peak flexion moments of the hip on the hemiplegic side were significantly higher compared with the control in the 14- and 13-year-old cases. The peak of ankle power generation (A2) in the 13- and 10-year-old cases were significantly lower on the uninvolved and hemiplegic sides, respectively, compared with the control. The peaks of hip flexor power generation (H3) in the 14- and 13-year-old cases were significantly higher on the uninvolved and hemiplegic sides, respectively. The A2/H3 ratios were significantly lower on the uninvolved and hemiplegic sides compared with the control, and the ratio for the hemiplegic side was lower than that for the uninvolved side. [Conclusion] This study shows that propulsion of walking is generated by hip, rather than the ankle, on both the hemiplegic and involved sides.

  18. Normal Anatomy and Compression Areas of Nerves of the Foot and Ankle: US and MR Imaging with Anatomic Correlation.

    PubMed

    De Maeseneer, Michel; Madani, Hardi; Lenchik, Leon; Kalume Brigido, Monica; Shahabpour, Maryam; Marcelis, Stefaan; de Mey, Johan; Scafoglieri, Aldo

    2015-01-01

    The anatomy of the nerves of the foot and ankle is complex, and familiarity with the normal anatomy and course of these nerves as well as common anatomic variants is essential for correct identification at imaging. Ultrasonography (US) and magnetic resonance (MR) imaging allow visualization of these nerves and may facilitate diagnosis of various compression syndromes, such as "jogger's heel," Baxter neuropathy, and Morton neuroma. It may be difficult to distinguish the nerves from adjacent vasculature at MR imaging, and US can help in differentiation. The authors review the normal anatomy and common variants of the nerves of the foot and ankle, with use of dissected specimens and correlative US and MR imaging findings. In addition, the authors illustrate proper probe positioning, which is essential for visualizing the nerves at US. The authors' discussion focuses on the superficial and deep peroneal, sural, saphenous, tibial, medial and lateral plantar, medial and inferior calcaneal, common digital, and medial proper plantar digital nerves.

  19. Military Exercises, Knee and Ankle Joint Position Sense, and Injury in Male Conscripts: A Pilot Study

    PubMed Central

    Mohammadi, Farshid; Azma, Kamran; Naseh, Iman; Emadifard, Reza; Etemadi, Yasaman

    2013-01-01

    Context: The high incidence of lower limb injuries associated with physical exercises in military conscripts suggests that fatigue may be a risk factor for injuries. Researchers have hypothesized that lower limb injuries may be related to altered ankle and knee joint position sense (JPS) due to fatigue. Objective: To evaluate if military exercises could alter JPS and to examine the possible relation of JPS to future lower extremity injuries in military service. Design: Cohort study. Setting: Laboratory. Patients or Other Participants: A total of 50 male conscripts (age = 21.4 ± 2.3 years, height = 174.5 ± 6.4 cm, mass = 73.1 ± 6.3 kg) from a unique military base were recruited randomly. Main Outcome Measure(s): Participants performed 8 weeks of physical activities at the beginning of a military course. In the first part of the study, we instructed participants to recognize predetermined positions before and after military exercises so we could examine the effects of military exercise on JPS. The averages of the absolute error and the variable error of 3 trials were recorded. We collected data on the frequency of lower extremity injuries over 8 weeks. Next, the participants were divided into 2 groups: injured and uninjured. Separate 2 × 2 × 2 (group-by-time-by-joint) mixed-model analyses of variance were used to determine main effects and interactions of these factors for each JPS measure. In the second part of the study, we examined whether the effects of fatigue on JPS were related to the development of injury during an 8-week training program. We calculated Hedges effect sizes for JPS changes postexercise in each group and compared change scores between groups. Results: We found group-by-time interactions for all JPS variables (F range = 2.86–4.05, P < .01). All participants showed increases in JPS errors postexercise (P < .01), but the injured group had greater changes for all the variables (P < .01). Conclusions: Military conscripts who sustained lower

  20. Assessment of Ankle and Hindfoot Stability and Joint Pressures Using a Human Cadaveric Model of a Large Lateral Talar Process Excision

    PubMed Central

    Sands, Andrew; White, Charles; Blankstein, Michael; Zderic, Ivan; Wahl, Dieter; Ernst, Manuela; Windolf, Markus; Hagen, Jennifer E.; Richards, R. Geoff; Stoffel, Karl; Gueorguiev, Boyko

    2015-01-01

    Abstract Lateral talar process fragment excision may be followed by hindfoot instability and altered biomechanics. There is controversy regarding the ideal fragment size for internal fixation versus excision and a concern that excision of a large fragment may lead to significant instability. The aim of this study was to assess the effect of a simulated large lateral talar process excision on ankle and subtalar joint stability. A custom-made seesaw rig was designed to apply inversion/eversion stress loading on 7 fresh-frozen human cadaveric lower legs and investigate them in pre-excision, 5 cm3 and 10 cm3 lateral talar process fragment excision states. Anteroposterior radiographs were taken to assess ankle and subtalar joint tilt and calculate angular change from neutral hindfoot alignment to 10-kg forced inversion/eversion. Ankle joint pressures and contact areas were measured under 30-kg axial load in neutral hindfoot alignment. In comparison to the pre-excision state, no significantly different mediolateral angular change was observed in the subtalar joint after 5 and 10 cm3 lateral talar process fragment excision in inversion and eversion. With respect to the ankle joint, 10-cm3 fragment excision produced significantly bigger inversion tibiotalar tilt compared with the pre-excision state, P = .04. No significant change of the ankle joint pressure and contact area was detected after 5 and 10-cm3 excision in comparison with the pre-excison state. An excision of up to 10 cm3 of the lateral talar process does not cause a significant instability at the level of the subtalar joint but might be a destabilizing factor at the ankle joint under inversion stress. The latter could be related to extensive soft tissue dissection required for resection. PMID:25789950

  1. Ankle arthroscopy

    MedlinePlus

    Ankle surgery; Arthroscopy - ankle; Surgery - ankle - arthroscopy; Surgery - ankle - arthroscopic ... You will likely receive general anesthesia before this surgery. This means you will be asleep and unable ...

  2. Ageing effects on knee and ankle joint angles at key events and phases of the gait cycle.

    PubMed

    Begg, R K; Sparrow, W A

    2006-01-01

    The objective of this research was to determine whether joint angles at critical gait events and during major energy generation/absorption phases of the gait cycle would reliably discriminate age-related degeneration during unobstructed walking. The gaits of 24 healthy adults (12 young and 12 elderly) were analysed using the PEAK Motus motion analysis system. The elderly participants showed significantly greater single (60.3% versus 62.3%, p < 0.01) and double ( p < 0.05) support times, reduced knee flexion (47.7 degrees versus 43.0 degrees , p < 0.05) and ankle plantarflexion (16.8 degrees compared to 3.3 degrees , p = 0.053) at toe off, reduced knee flexion during push-off and reduced ankle dorsiflexion (16.8 degrees compared to 22.0 degrees , p < 0.05) during the swing phase. The plantarflexing ankle joint motion during the stance to swing phase transition (A2) for the young group (31.3 degrees ) was about twice ( p < 0.05) that of the elderly (16.9 degrees ). Reduced knee extension range of motion suggests that the elderly favoured a flexed-knee gait to assist in weight acceptance. Reduced dorsiflexion by the elderly in the swing phase implies greater risk of toe contact with obstacles. Overall, the results suggest that joint angle measures at critical events/phases in the gait cycle provide a useful indication of age-related degeneration in the control of lower limb trajectories during unobstructed walking.

  3. Age and gender differences in the control of vertical ground reaction force by the hip, knee and ankle joints.

    PubMed

    Toda, Haruki; Nagano, Akinori; Luo, Zhiwei

    2015-06-01

    [Purpose] This study examined the relationships between joint moment and the control of the vertical ground reaction force during walking in the elderly and young male and female individuals. [Subjects and Methods] Forty elderly people, 65 years old or older (20 males and 20 females), and 40 young people, 20 to 29 years old (20 males and 20 females), participated in this study. Joint moment and vertical ground reaction force during walking were obtained using a 3D motion analysis system and force plates. Stepwise linear regression analysis determined the joint moments that predict the amplitude of the vertical ground reaction force. [Results] Knee extension moment was related to the vertical ground reaction force in the young males and females. On the other hand, in the elderly females, hip, ankle, and knee joint moments were related to the first peak and second peak forces, and the minimum value of vertical ground reaction force, respectively. [Conclusion] Our results suggest that the young males and females make use of the knee joint moment to control of the vertical ground reaction force. There were differences between the elderly and the young females with regard to the joints used for the control of the vertical ground reaction force.

  4. Age and gender differences in the control of vertical ground reaction force by the hip, knee and ankle joints

    PubMed Central

    Toda, Haruki; Nagano, Akinori; Luo, Zhiwei

    2015-01-01

    [Purpose] This study examined the relationships between joint moment and the control of the vertical ground reaction force during walking in the elderly and young male and female individuals. [Subjects and Methods] Forty elderly people, 65 years old or older (20 males and 20 females), and 40 young people, 20 to 29 years old (20 males and 20 females), participated in this study. Joint moment and vertical ground reaction force during walking were obtained using a 3D motion analysis system and force plates. Stepwise linear regression analysis determined the joint moments that predict the amplitude of the vertical ground reaction force. [Results] Knee extension moment was related to the vertical ground reaction force in the young males and females. On the other hand, in the elderly females, hip, ankle, and knee joint moments were related to the first peak and second peak forces, and the minimum value of vertical ground reaction force, respectively. [Conclusion] Our results suggest that the young males and females make use of the knee joint moment to control of the vertical ground reaction force. There were differences between the elderly and the young females with regard to the joints used for the control of the vertical ground reaction force. PMID:26180331

  5. Effects of muscle strength asymmetry between left and right on isokinetic strength of the knee and ankle joints depending on athletic performance level

    PubMed Central

    Jeon, Kyoungkyu; Chun, Sungyung; Seo, Byoungdo

    2016-01-01

    [Purpose] The aim of this study was to collect basic data on the effect of asymmetry on the muscle strength of the left and right knee and ankle joints of soccer players at varying athletic performance levels, to guide the development of improved exercise programs. [Subjects and Methods] Forty-nine soccer players at three athletic performance levels participated: 15 professional, 16 amateur, and 18 college. Knee extensor and flexor strength were measured at 60°/sec and 180°/sec, and ankle plantar flexor and dorsiflexor strength were measured at 30°/sec and at 120°/sec. Variables were analyzed by one-way ANOVA. [Results] College soccer players showed greater muscle strength at 60°/sec and 180°/sec in the knee extension muscles of both the right and the left sides, lower muscle strength at 30°/sec and 120°/sec in the dorsiflexor of the right ankle, and similar levels of asymmetry between left and right. The maximum muscle strength on the same side significantly differed in the right ankle joint, with asymmetry between left and right at 30°/sec and 120°/sec. [Conclusion] These findings suggest that muscle strength asymmetry in the ankle joint may lead to counterbalancing muscle strengthening of the knee joint to maintain the center of body mass. PMID:27190469

  6. Effects of muscle strength asymmetry between left and right on isokinetic strength of the knee and ankle joints depending on athletic performance level.

    PubMed

    Jeon, Kyoungkyu; Chun, Sungyung; Seo, Byoungdo

    2016-04-01

    [Purpose] The aim of this study was to collect basic data on the effect of asymmetry on the muscle strength of the left and right knee and ankle joints of soccer players at varying athletic performance levels, to guide the development of improved exercise programs. [Subjects and Methods] Forty-nine soccer players at three athletic performance levels participated: 15 professional, 16 amateur, and 18 college. Knee extensor and flexor strength were measured at 60°/sec and 180°/sec, and ankle plantar flexor and dorsiflexor strength were measured at 30°/sec and at 120°/sec. Variables were analyzed by one-way ANOVA. [Results] College soccer players showed greater muscle strength at 60°/sec and 180°/sec in the knee extension muscles of both the right and the left sides, lower muscle strength at 30°/sec and 120°/sec in the dorsiflexor of the right ankle, and similar levels of asymmetry between left and right. The maximum muscle strength on the same side significantly differed in the right ankle joint, with asymmetry between left and right at 30°/sec and 120°/sec. [Conclusion] These findings suggest that muscle strength asymmetry in the ankle joint may lead to counterbalancing muscle strengthening of the knee joint to maintain the center of body mass. PMID:27190469

  7. Effects of muscle strength asymmetry between left and right on isokinetic strength of the knee and ankle joints depending on athletic performance level.

    PubMed

    Jeon, Kyoungkyu; Chun, Sungyung; Seo, Byoungdo

    2016-04-01

    [Purpose] The aim of this study was to collect basic data on the effect of asymmetry on the muscle strength of the left and right knee and ankle joints of soccer players at varying athletic performance levels, to guide the development of improved exercise programs. [Subjects and Methods] Forty-nine soccer players at three athletic performance levels participated: 15 professional, 16 amateur, and 18 college. Knee extensor and flexor strength were measured at 60°/sec and 180°/sec, and ankle plantar flexor and dorsiflexor strength were measured at 30°/sec and at 120°/sec. Variables were analyzed by one-way ANOVA. [Results] College soccer players showed greater muscle strength at 60°/sec and 180°/sec in the knee extension muscles of both the right and the left sides, lower muscle strength at 30°/sec and 120°/sec in the dorsiflexor of the right ankle, and similar levels of asymmetry between left and right. The maximum muscle strength on the same side significantly differed in the right ankle joint, with asymmetry between left and right at 30°/sec and 120°/sec. [Conclusion] These findings suggest that muscle strength asymmetry in the ankle joint may lead to counterbalancing muscle strengthening of the knee joint to maintain the center of body mass.

  8. The Influence of Lumbar Joint Mobilization on Joint Position Sense in Normal Adults

    PubMed Central

    Gong, Wontae

    2014-01-01

    [Purpose] The purpose of this study was to determine the effects of lumbar joint mobilization on the joint position sense (JPS) of normal adults. [Subjects] A total of 30 normal adults were divided into an experimental group (n = 15) and a control group (n = 15). [Methods] The experimental group received lumbar joint mobilization and massage, and the control group received massage only. Both the experimental and control groups were evaluated for joint position error (JPE) by using a digital dual inclinometer before and after the experiment. [Results] In the before and after comparison for the experimental group, statistically significant differences were found in flexion, extension, left lateral flexion, and right lateral flexion. There was no statistically significant difference in the before and after comparison for the control group. [Conclusion] Because lumbar joint mobilization can reduce JPE and improve JPS, its use in the treatment of patients with lumbar problems is recommended. PMID:25540513

  9. Inferring Muscle-Tendon Unit Power from Ankle Joint Power during the Push-Off Phase of Human Walking: Insights from a Multiarticular EMG-Driven Model

    PubMed Central

    2016-01-01

    Introduction Inverse dynamics joint kinetics are often used to infer contributions from underlying groups of muscle-tendon units (MTUs). However, such interpretations are confounded by multiarticular (multi-joint) musculature, which can cause inverse dynamics to over- or under-estimate net MTU power. Misestimation of MTU power could lead to incorrect scientific conclusions, or to empirical estimates that misguide musculoskeletal simulations, assistive device designs, or clinical interventions. The objective of this study was to investigate the degree to which ankle joint power overestimates net plantarflexor MTU power during the Push-off phase of walking, due to the behavior of the flexor digitorum and hallucis longus (FDHL)–multiarticular MTUs crossing the ankle and metatarsophalangeal (toe) joints. Methods We performed a gait analysis study on six healthy participants, recording ground reaction forces, kinematics, and electromyography (EMG). Empirical data were input into an EMG-driven musculoskeletal model to estimate ankle power. This model enabled us to parse contributions from mono- and multi-articular MTUs, and required only one scaling and one time delay factor for each subject and speed, which were solved for based on empirical data. Net plantarflexing MTU power was computed by the model and quantitatively compared to inverse dynamics ankle power. Results The EMG-driven model was able to reproduce inverse dynamics ankle power across a range of gait speeds (R2 ≥ 0.97), while also providing MTU-specific power estimates. We found that FDHL dynamics caused ankle power to slightly overestimate net plantarflexor MTU power, but only by ~2–7%. Conclusions During Push-off, FDHL MTU dynamics do not substantially confound the inference of net plantarflexor MTU power from inverse dynamics ankle power. However, other methodological limitations may cause inverse dynamics to overestimate net MTU power; for instance, due to rigid-body foot assumptions. Moving

  10. Shoe collar height effect on athletic performance, ankle joint kinematics and kinetics during unanticipated maximum-effort side-cutting performance.

    PubMed

    Lam, Gilbert Wing Kai; Park, Eun Jung; Lee, Ki-Kwang; Cheung, Jason Tak-Man

    2015-01-01

    Side-step cutting manoeuvres comprise the coordination between planting and non-planting legs. Increased shoe collar height is expected to influence ankle biomechanics of both legs and possibly respective cutting performance. This study examined the shoe collar height effect on kinematics and kinetics of planting and non-planting legs during an unanticipated side-step cutting. Fifteen university basketball players performed maximum-effort side-step cutting to the left 45° direction or a straight ahead run in response to a random light signal. Seven successful cutting trials were collected for each condition. Athletic performance, ground reaction force, ankle kinematics and kinetics of both legs were analysed using paired t-tests. Results indicated that high-collar shoes resulted in less ankle inversion and external rotation during initial contact for the planting leg. The high-collar shoes also exhibited a smaller ankle range of motion in the sagittal and transverse planes for both legs, respectively. However, no collar effect was found for ankle moments and performance indicators including cutting performance time, ground contact time, propulsion ground reaction forces and impulses. These findings indicated that high-collar shoes altered ankle positioning and restricted ankle joint freedom movements in both legs, while no negative effect was found for athletic cutting performance.

  11. Outcomes of temporomandibular joint arthroscopy in patients with painful but otherwise normal joints.

    PubMed

    Dimitroulis, George

    2015-07-01

    The aim of this retrospective clinical study was to assess the clinical outcomes of temporomandibular joint (TMJ) arthroscopy in patients who presented with category 1 normal joints. The null hypothesis being tested was that patients with normal joints do not respond to TMJ arthroscopy. The clinical records of 116 patients who had undergone TMJ arthroscopy by the author from 2010 to 2013 were retrieved and individually analysed for inclusion in this retrospective, cohort clinical study. The inclusion criteria used to select patients for this study were those who had arthroscopically proven category 1 normal joints, free of intra-articular pathology. Of the 14 patients who were found to have normal joints, only 10 could be contacted for a follow-up survey. Despite the fact that all patients were informed that no joint pathology was found, six out of the 10 patients reported improvement in their temporomandibular disorder (TMD) symptoms that lasted for more than 6 months following TMJ arthroscopy. The results of this investigation indicate that we can reject the null hypothesis, and that patients with normal TMJs do indeed respond to TMJ arthroscopy. What this limited study has highlighted is the pervasive effects of the placebo that all surgeons need to keep in mind when formulating treatment plans for patients with TMD.

  12. Total ankle replacement. Early experiences with STAR prosthesis.

    PubMed Central

    Murnaghan, J. M.; Warnock, D. S.; Henderson, S. A.

    2005-01-01

    Early designs of Total Ankle Replacement (TAR) had a high failure rate. More recent experience with the 3-piece, meniscal bearing, total ankle replacement has been more promising. We report a review of the early results of our first 22 prostheses in 20 patients undergoing Scandinavian Total Ankle Replacement (STAR) in Northern Ireland. There was a mean follow-up time of 26 months. Seventeen patients are pain-free at the ankle joint during normal daily activities. Two of the early cases have required revision surgery due to technical errors. Other complications have included malleolar fractures, poor wound healing and postoperative stiffness. These early results show high levels of patient satisfaction, and we are encouraged to continue with total ankle arthroplasty. There is a steep initial learning curve and use of TAR should be restricted to foot and ankle surgeons. Images Fig 1 Figs 2a and b Figs 2 c and d PMID:16022128

  13. Effects of Ankle Arthrodesis on Biomechanical Performance of the Entire Foot

    PubMed Central

    Wang, Yan; Li, Zengyong; Wong, Duo Wai-Chi; Zhang, Ming

    2015-01-01

    Background/Methodology Ankle arthrodesis is one popular surgical treatment for ankle arthritis, chronic instability, and degenerative deformity. However, complications such as foot pain, joint arthritis, and bone fracture may cause patients to suffer other problems. Understanding the internal biomechanics of the foot is critical for assessing the effectiveness of ankle arthrodesis and provides a baseline for the surgical plan. This study aimed to understand the biomechanical effects of ankle arthrodesis on the entire foot and ankle using finite element analyses. A three-dimensional finite element model of the foot and ankle, involving 28 bones, 103 ligaments, the plantar fascia, major muscle groups, and encapsulated soft tissue, was developed and validated. The biomechanical performances of a normal foot and a foot with ankle arthrodesis were compared at three gait instants, first-peak, mid-stance, and second-peak. Principal Findings/Conclusions Changes in plantar pressure distribution, joint contact pressure and forces, von Mises stress on bone and foot deformation were predicted. Compared with those in the normal foot, the peak plantar pressure was increased and the center of pressure moved anteriorly in the foot with ankle arthrodesis. The talonavicular joint and joints of the first to third rays in the hind- and mid-foot bore the majority of the loading and sustained substantially increased loading after ankle arthrodesis. An average contact pressure of 2.14 MPa was predicted at the talonavicular joint after surgery and the maximum variation was shown to be 80% in joints of the first ray. The contact force and pressure of the subtalar joint decreased after surgery, indicating that arthritis at this joint was not necessarily a consequence of ankle arthrodesis but rather a progression of pre-existing degenerative changes. Von Mises stress in the second and third metatarsal bones at the second-peak instant increased to 52 MPa and 34 MPa, respectively, after

  14. Expedited Patient-Specific Assessment of Contact Stress Exposure in the Ankle Joint Following Definitive Articular Fracture Reduction

    PubMed Central

    Kern, Andrew M.; Anderson, Donald D.

    2015-01-01

    Acute injury severity, altered joint kinematics, and joint incongruity are three important mechanical factors linked to post-traumatic osteoarthritis (PTOA). Finite element analysis (FEA) was previously used to assess the influence of increased contact stress due to joint incongruity on PTOA development. While promising agreement with PTOA development was seen, the inherent complexities of contact FEA limited the numbers of subjects that could be analyzed. Discrete element analysis (DEA) is a simplified methodology for contact stress computation, which idealizes contact surfaces as a bed of independent linear springs. In this study, DEA was explored as an expedited alternative to FEA contact stress exposure computation. DEA was compared to FEA using results from a previously completed validation study of two cadaveric human ankles, as well as a previous study of post-operative contact stress exposure in 11 patients with tibial plafond fracture. DEA-computed maximum contact stresses were within 19% of those experimentally measured, with 90% of the contact area having computed contact stress values within 1 MPa of those measured. In the 11 fractured ankles, maximum contact stress and contact area differences between DEA and FEA were 0.85±0.64 MPa and 22.5±11.5 mm2. As a predictive measure for PTOA development, both DEA and FEA had 100% concordance with presence of OA (KL grade ≥ 2) and >95% concordance with KL grade at 2 years. These results support DEA as a reasonable alternative to FEA for computing contact stress exposures following surgical reduction of a tibial plafond fracture. PMID:26105660

  15. Expedited patient-specific assessment of contact stress exposure in the ankle joint following definitive articular fracture reduction.

    PubMed

    Kern, Andrew M; Anderson, Donald D

    2015-09-18

    Acute injury severity, altered joint kinematics, and joint incongruity are three important mechanical factors linked to post-traumatic osteoarthritis (PTOA). Finite element analysis (FEA) was previously used to assess the influence of increased contact stress due to joint incongruity on PTOA development. While promising agreement with PTOA development was seen, the inherent complexities of contact FEA limited the numbers of subjects that could be analyzed. Discrete element analysis (DEA) is a simplified methodology for contact stress computation, which idealizes contact surfaces as a bed of independent linear springs. In this study, DEA was explored as an expedited alternative to FEA contact stress exposure computation. DEA was compared to FEA using results from a previously completed validation study of two cadaveric human ankles, as well as a previous study of post-operative contact stress exposure in 11 patients with tibial plafond fracture. DEA-computed maximum contact stresses were within 19% of those experimentally measured, with 90% of the contact area having computed contact stress values within 1MPa of those measured. In the 11 fractured ankles, maximum contact stress and contact area differences between DEA and FEA were 0.85 ± 0.64 MPa and 22.5 ± 11.5mm(2). As a predictive measure for PTOA development, both DEA and FEA had 100% concordance with presence of OA (KL grade ≥ 2) and >95% concordance with KL grade at 2 years. These results support DEA as a reasonable alternative to FEA for computing contact stress exposures following surgical reduction of a tibial plafond fracture.

  16. Comparative study of therapies for fibular ligament rupture of the lateral ankle joint in competitive basketball players.

    PubMed

    Klein, J; Höher, J; Tiling, T

    1993-01-01

    This retrospective study compares the results of different therapies for fibular ligament rupture in a homogenous group of professional athletes. The endpoint "competitive sports" was an outcome consideration. Subjects were examined by means of a standardized questionnaire and a structured interview. One hundred and seventy-nine of the questionnaires were completed and returned for evaluation. All of the basketball players with severe ankle sprain (supination trauma with swelling, pain, and inability to bear stress) were included. Those players with fractures of the foot, pronation trauma, or additional distal fibula or tibia fractures were excluded from this study. Of the 179 basketball players 160 (89%) had suffered severe ankle sprain. The treatment was divided into three groups: primary surgery (N = 35), plaster cast (N = 39), and functional treatment (N = 89). While simple ligament injuries (Grade I and II) were mostly treated functionally, complex ligament injuries (Grade III) were usually operated on. A total of 119 (74%) of the players reported no further pain. For pain reduction surgical and functional treatments showed advantages over plaster treatment. In the surgical group 63% of the players judged their regained stability to be equivalent to that of their healthy leg. Only 50% of the players in the plaster and functional groups believed their ankle joints to have regained the same stability as before their injuries. Despite the achievement of good results through surgery, there were clear differences in the players' assessments of their performance in competitive sports. Most subjects (92%) did not have any problems in everyday life regardless of which kind of therapy had been chosen.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Current concepts: tissue engineering and regenerative medicine applications in the ankle joint

    PubMed Central

    Correia, S. I.; Pereira, H.; Silva-Correia, J.; Van Dijk, C. N.; Espregueira-Mendes, J.; Oliveira, J. M.; Reis, R. L.

    2014-01-01

    Tissue engineering and regenerative medicine (TERM) has caused a revolution in present and future trends of medicine and surgery. In different tissues, advanced TERM approaches bring new therapeutic possibilities in general population as well as in young patients and high-level athletes, improving restoration of biological functions and rehabilitation. The mainstream components required to obtain a functional regeneration of tissues may include biodegradable scaffolds, drugs or growth factors and different cell types (either autologous or heterologous) that can be cultured in bioreactor systems (in vitro) prior to implantation into the patient. Particularly in the ankle, which is subject to many different injuries (e.g. acute, chronic, traumatic and degenerative), there is still no definitive and feasible answer to ‘conventional’ methods. This review aims to provide current concepts of TERM applications to ankle injuries under preclinical and/or clinical research applied to skin, tendon, bone and cartilage problems. A particular attention has been given to biomaterial design and scaffold processing with potential use in osteochondral ankle lesions. PMID:24352667

  18. Design of a Robotic Ankle Joint for a Microspine-Based Robot

    NASA Technical Reports Server (NTRS)

    Thatte, Nitish

    2011-01-01

    Successful robotic exploration of near-Earth asteroids necessitates a method of securely anchoring to the surface of these bodies without gravitational assistance. Microspine grip- per arrays that can grasp rock faces are a potential solution to this problem. A key component of a future microspine-based rover will be the ankle used to attach each microspine gripper to the robot. The ankle's purpose is twofold: 1) to allow the gripper to conform to the rock so a higher percentage of microspines attach to the surface, and 2) to neutralize torques that may dislodge the grippers from the wall. Parts were developed using computer aided design and manufactured using a variety of methods including selective laser sintering, CNC milling, and traditional manual machining techniques. Upon completion of the final prototype, the gripper and ankle system was tested to demonstrate robotic engagement and disengagement of the gripper and to determine load bearing ability. The immediate application of this project is to out t the Lemur IIb robot so it can climb and hang from rock walls.

  19. Closed medial total subtalar joint dislocation without ankle fracture: a case report

    PubMed Central

    2014-01-01

    Introduction Total subtalar dislocation without fracture of the ankle is a rare clinical entity; it is usually due to a traumatic high-energy mechanism. Standard treatment is successful closed reduction under general anesthesia followed by non-weight bearing and ankle immobilization with a below-knee cast for 6 weeks. Case presentation We present the case of a 30-year-old Moroccan woman who was involved in a road traffic accident. She subsequently received a radiological assessment that objectified a total subtalar dislocation without fracture of her ankle. She was immediately admitted to the operating theater where an immediate reduction was performed under sedation, and immobilization in a plaster boot was adopted for 8 weeks. The management of this traumatic lesion is discussed in the light of the literature. Conclusions Medial subtalar dislocation is a rare dislocation and is not commonly seen as a sports injury because it requires transfer of a large amount of kinetic energy. The weaker talocalcaneal and talonavicular ligaments often bear the brunt of the energy and are more commonly disrupted, compared to the relatively stronger calcaneonavicular ligament. Urgent reduction is important, and closed reduction under general anesthesia is usually successful, often facilitated by keeping the knee in flexion to relax the gastrocnemius muscle. Long-term sequelae include talar avascular necrosis and osteochondral fracture, as well as chronic instability and pain. PMID:25240955

  20. The main function of ankle braces is to control the joint position before landing.

    PubMed

    Eils, Eric; Rosenbaum, Dieter

    2003-03-01

    The aim of the present investigation was to evaluate the stabilizing effect of 10 different ankle braces during simulated inversion on a tilting platform. Twenty-five subjects participated in the study (23 +/- 3 yrs, 71 +/- 12 kg, 177 +/- 9 cm). Ten commercially available ankle braces and a trapdoor in combination with a goniometer system that measured hindfoot inversion inside the shoe were used. Inversion was subdivided into a free fall and a maximum inversion phase. Results showed that all braces restricted inversion significantly between 51% and 15% compared to the no-brace condition but distinct differences between models were found. Maximum inversion angle and inversion velocity were lower for those braces that restricted inversion most effectively during the free fall phase. Reaction times of the peroneus longus did not appear to influence the degree of inversion. Relatively constant differences between free fall and maximum inversion angles for all models (between 6 degrees and 10 degrees) and a high correlation between these two parameters suggests that the main function of ankle braces is to restrict inversion during the free fall phase and not at the extremes of motion.

  1. Understanding the effect of touchdown distance and ankle joint kinematics on sprint acceleration performance through computer simulation.

    PubMed

    Bezodis, Neil Edward; Trewartha, Grant; Salo, Aki Ilkka Tapio

    2015-06-01

    This study determined the effects of simulated technique manipulations on early acceleration performance. A planar seven-segment angle-driven model was developed and quantitatively evaluated based on the agreement of its output to empirical data from an international-level male sprinter (100 m personal best = 10.28 s). The model was then applied to independently assess the effects of manipulating touchdown distance (horizontal distance between the foot and centre of mass) and range of ankle joint dorsiflexion during early stance on horizontal external power production during stance. The model matched the empirical data with a mean difference of 5.2%. When the foot was placed progressively further forward at touchdown, horizontal power production continually reduced. When the foot was placed further back, power production initially increased (a peak increase of 0.7% occurred at 0.02 m further back) but decreased as the foot continued to touchdown further back. When the range of dorsiflexion during early stance was reduced, exponential increases in performance were observed. Increasing negative touchdown distance directs the ground reaction force more horizontally; however, a limit to the associated performance benefit exists. Reducing dorsiflexion, which required achievable increases in the peak ankle plantar flexor moment, appears potentially beneficial for improving early acceleration performance.

  2. Comparisons of knee and ankle joint angles and ground reaction force according to functional differences during single-leg drop landing

    PubMed Central

    Kim, Kewwan; Jeon, Kyoungkyu

    2016-01-01

    [Purpose] The purpose of this study was to determine potential predictors of functional instability of the knee and ankle joints during single-leg drop landing based on the prior history of injury. [Subjects and Methods] The subjects were 24 collegiate soccer players without pain or dysfunction. To compare the differences between the stable and unstable sides during single-leg drop landing, 8 motion analysis cameras and a force plate were used. The Cortex 4 software was used for a biomechanical analysis of 3 events. An independent t-test was used for statistical comparison between both sides; p<0.05 indicated significance. [Results] The knee joint movements showed gradual flexion in the sagittal plane. The unstable-side ankle joint showed plantar flexion of approximately 2° relative to the stable side. In the coronal plane, the unstable-side knee joint differed from the stable side in its tendency for valgus movement. The unstable-side ankle joint showed contrasting movement compared with the stable side, and the difference was significant. Regarding the vertical ground reaction force, the stable side showed maximum knee flexion that was approximately 0.1 BW lower than that of the unstable side. [Conclusion] Increasing the flexion angle of the knee joint can help prevent injury during landing. PMID:27190444

  3. Movement Behavior of High-Heeled Walking: How Does the Nervous System Control the Ankle Joint during an Unstable Walking Condition?

    PubMed Central

    Alkjær, Tine; Raffalt, Peter; Petersen, Nicolas C.; Simonsen, Erik B.

    2012-01-01

    The human locomotor system is flexible and enables humans to move without falling even under less than optimal conditions. Walking with high-heeled shoes constitutes an unstable condition and here we ask how the nervous system controls the ankle joint in this situation? We investigated the movement behavior of high-heeled and barefooted walking in eleven female subjects. The movement variability was quantified by calculation of approximate entropy (ApEn) in the ankle joint angle and the standard deviation (SD) of the stride time intervals. Electromyography (EMG) of the soleus (SO) and tibialis anterior (TA) muscles and the soleus Hoffmann (H-) reflex were measured at 4.0 km/h on a motor driven treadmill to reveal the underlying motor strategies in each walking condition. The ApEn of the ankle joint angle was significantly higher (p<0.01) during high-heeled (0.38±0.08) than during barefooted walking (0.28±0.07). During high-heeled walking, coactivation between the SO and TA muscles increased towards heel strike and the H-reflex was significantly increased in terminal swing by 40% (p<0.01). These observations show that high-heeled walking is characterized by a more complex and less predictable pattern than barefooted walking. Increased coactivation about the ankle joint together with increased excitability of the SO H-reflex in terminal swing phase indicates that the motor strategy was changed during high-heeled walking. Although, the participants were young, healthy and accustomed to high-heeled walking the results demonstrate that that walking on high-heels needs to be controlled differently from barefooted walking. We suggest that the higher variability reflects an adjusted neural strategy of the nervous system to control the ankle joint during high-heeled walking. PMID:22615997

  4. Sodium Magnetic Resonance Imaging of Ankle Joint in Cadaver Specimens, Volunteers, and Patients After Different Cartilage Repair Techniques at 7 T

    PubMed Central

    Zbýň, Štefan; Brix, Martin O.; Juras, Vladimir; Domayer, Stephan E.; Walzer, Sonja M.; Mlynarik, Vladimir; Apprich, Sebastian; Buckenmaier, Kai; Windhager, Reinhard; Trattnig, Siegfried

    2015-01-01

    Objectives The goal of cartilage repair techniques such as microfracture (MFX) or matrix-associated autologous chondrocyte transplantation (MACT) is to produce repair tissue (RT) with sufficient glycosaminoglycan (GAG) content. Sodium magnetic resonance imaging (MRI) offers a direct and noninvasive evaluation of the GAG content in native cartilage and RT. In the femoral cartilage, this method was able to distinguish between RTs produced by MFX and MACT having different GAG contents. However, it needs to be clarified whether sodium MRI can be useful for evaluating RT in thin ankle cartilage. Thus, the aims of this 7-T study were (1) to validate our sodium MRI protocol in cadaver ankle samples, (2) to evaluate the sodium corrected signal intensities (cSI) in cartilage of volunteers, (3) and to compare sodium values in RT between patients after MFX and MACT treatment. Materials and Methods Five human cadaver ankle samples as well as ankles of 9 asymptomatic volunteers, 6 MFX patients and 6 MACT patients were measured in this 7-T study. Sodium values from the ankle samples were compared with histochemically evaluated GAG content. In the volunteers, sodium cSI values were calculated in the cartilages of ankle and subtalar joint. In the patients, sodium cSI in RT and reference cartilage were measured, morphological appearance of RT was evaluated using the magnetic resonance observation of cartilage repair tissue (MOCART) scoring system, and clinical outcome before and after surgery was assessed using the American Orthopaedic Foot and Ankle Society score and Modified Cincinnati Knee Scale. All regions of interest were defined on morphological images and subsequently transferred to the corresponding sodium images. Analysis of variance, t tests, and Pearson correlation coefficients were evaluated. Results In the patients, significantly lower sodium cSI values were found in RT than in reference cartilage for the MFX (P = 0.007) and MACT patients (P = 0.008). Sodium cSI and

  5. The influence of antagonist muscle control strategies on the isometric frequency response of the cat's ankle joint.

    PubMed

    Goodwin, A; Zhou, B H; Baratta, R V; Solomonow, M; Keegan, A P

    1997-07-01

    This study investigated the effect of various strategies to control the interaction between agonist and antagonist muscles on the frequency response of the isometric cat ankle joint actuated by the tibialis anterior (TA) and soleus (SOL) muscles. Some strategies were based on the physiologic need for increasing joint stability during forceful contractions; with these strategies, the proportional rate of physiologic antagonist activity was termed antagonist gain. Other strategies were based on the electrical stimulation literature, which advocates co-contraction at low force levels. The range of crossover of antagonist activity to the agonist's domain was termed overlap. Strategies consisting of 0%, 10%, and 20% antagonist gain were combined with 0%, 50%, and 100% overlap for a total of nine strategies. These were applied to the TA and SOL using sinusoidal input signals varying in frequency from 0.4 to 6 Hz. Gain and phase Bode plots were constructed through the use of the fast Fourier transforms (FFT's); and analysis of variance determined the significance of differences in gain and phase across frequencies. Best-fit models consisting of four poles and two zeroes were used to fit the experimental data and compared against an analytical model of muscles acting independently across the joint. Harmonic distortion was calculated to evaluate signal quality. It was found that changing the overlap and the antagonist gain produces significant changes in the dynamic response of the two-muscle joint system. The analytical approach to modeling such a system tends to consistently overestimate gain. It is suggested that signal quality is optimal when a moderate amount of antagonist gain (10%) is engaged, with overlap of 50% to smooth transitions between opposing movements. It is expected that this type of strategy will achieve optimum signal quality while preserving the long-term integrity of the joint. PMID:9210823

  6. Effect of treadmill walking with ankle stretching orthosis on ankle flexibility and gait

    PubMed Central

    Cho, Young-ki; Kim, Si-hyun; Jeon, In-cheol; Ahn, Sun-hee; Kwon, Oh-yun

    2015-01-01

    [Purpose] The purpose of this study was to evaluate the kinematics of the ankle in the lunge to estabilish effectiveness of an ankle stretching orthosis (ASO) on the ankle dorsiflexion range of motion (ROM) of individuals with limited dorsiflexion ROM. [Subjects and Methods] Forty ankles with decreased dorsiflexion ROM of 20 participants were evaluated in this study. After wearing the ASO, participants walked on a treadmill for 15 minutes. Participants walked on the treadmill at a self-selected comfortable speed. Ankle dorsiflexion ROM, maximum dorsiflexion ROM before heel-off, and time to heel-off during the stance phase of gait were measured before and after 15 minutes of treadmill walking with the ASO. The differences in all variables between before and after treadmill walking with ASO were analyzed using the paired t-test. [Results] Ankle active and passive ROM, and dorsiflexion ROM during lunge increased significantly after treadmill walking with ASO. Treadmill walking with the ASO significantly increased the angle of maximal dorsiflexion before heel-off and time to heel-off during the stance phase. [Conclusion] The results of this study show that treadmill walking with the ASO effectively improved ankle flexibility and restored the normal gait pattern of the ankle joint by increasing dorsiflexion ROM, maximal angle of dorsiflexion, and time to heel-off in the stance phase. PMID:25995601

  7. Summary of Human Ankle Mechanical Impedance During Walking

    PubMed Central

    Rouse, Elliott J.; Krebs, Hermano Igo

    2016-01-01

    The human ankle joint plays a critical role during walking and understanding the biomechanical factors that govern ankle behavior and provides fundamental insight into normal and pathologically altered gait. Previous researchers have comprehensively studied ankle joint kinetics and kinematics during many biomechanical tasks, including locomotion; however, only recently have researchers been able to quantify how the mechanical impedance of the ankle varies during walking. The mechanical impedance describes the dynamic relationship between the joint position and the joint torque during perturbation, and is often represented in terms of stiffness, damping, and inertia. The purpose of this short communication is to unify the results of the first two studies measuring ankle mechanical impedance in the sagittal plane during walking, where each study investigated differing regions of the gait cycle. Rouse et al. measured ankle impedance from late loading response to terminal stance, where Lee et al. quantified ankle impedance from pre-swing to early loading response. While stiffness component of impedance increases significantly as the stance phase of walking progressed, the change in damping during the gait cycle is much less than the changes observed in stiffness. In addition, both stiffness and damping remained low during the swing phase of walking. Future work will focus on quantifying impedance during the “push off” region of stance phase, as well as measurement of these properties in the coronal plane. PMID:27766187

  8. 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

  9. Inferior joint space arthrography of normal temporomandibular joints: Reassessment of diagnostic criteria

    SciTech Connect

    Kaplan, P.A.; Tu, H.K.; Sleder, P.R.; Lydiatt, D.D.; Laney, T.J.

    1986-06-01

    Inferior joint space arthrograms of the temporomandibular joints of 31 healthy volunteers (62 joints) were obtained to determine normal arthrographic findings. The superior margin of the anterior recess was smooth and flat in 68% of the joints and concave in 32% with the subjects' mouths closed. The concavity was the result of the anterior ridge of the meniscus impinging on the contrast material. The concave impression could be distinguished easily from an anteriorly displaced meniscus on videotaped studies, which demonstrated a smooth transition of contrast material from the anterior to the posterior recess during opening of a subject's mouth. With the mouth open, the anterior recess decreased in size, appearing as a small, crescent-shaped collection of contrast material anterior to the head of the condyle in 52 joints (84%); it remained large in ten joints (16%) at maximal mouth opening. The configuration of the posterior recess was identical to that described previously; however, with the subjects' mouths closed, it was larger than the anterior recess, contrary to most previously reported results.

  10. Bilateral Ankle and Subtalar Joint Fusion Secondary to Guillain Barré-Induced Foot Drop.

    PubMed

    Seidel, Jay; Mathew, Bindu; Marks, Jeffrey

    2016-01-01

    Guillain-Barré syndrome is a serious disorder that occurs when the body's immune system mistakenly attacks the peripheral nervous system. This leads to nerve inflammation and damage that can cause muscle weakness and/or paralysis, including foot drop. Therapy ranges from supportive measures, such as physical therapy, to surgical intervention. It appears from the published data that these patients, generally, have been left to their own devices, because no known cure is available, necessitating reliance on others for their daily activities and ambulation. We present a unique surgical option, with a follow-up period of 24 months, in which bilateral subtalar and ankle fusion allowed unassisted ambulation to a patient who might otherwise have never walked again. PMID:25128306

  11. Bilateral Ankle and Subtalar Joint Fusion Secondary to Guillain Barré-Induced Foot Drop.

    PubMed

    Seidel, Jay; Mathew, Bindu; Marks, Jeffrey

    2016-01-01

    Guillain-Barré syndrome is a serious disorder that occurs when the body's immune system mistakenly attacks the peripheral nervous system. This leads to nerve inflammation and damage that can cause muscle weakness and/or paralysis, including foot drop. Therapy ranges from supportive measures, such as physical therapy, to surgical intervention. It appears from the published data that these patients, generally, have been left to their own devices, because no known cure is available, necessitating reliance on others for their daily activities and ambulation. We present a unique surgical option, with a follow-up period of 24 months, in which bilateral subtalar and ankle fusion allowed unassisted ambulation to a patient who might otherwise have never walked again.

  12. Differences Regarding Branded HA in Italy, Part 2: Data from Clinical Studies on Knee, Hip, Shoulder, Ankle, Temporomandibular Joint, Vertebral Facets, and Carpometacarpal Joint

    PubMed Central

    Migliore, A.; Bizzi, E.; De Lucia, O.; Delle Sedie, A.; Tropea, S.; Bentivegna, M.; Mahmoud, A.; Foti, C.

    2016-01-01

    OBJECTIVES The aim of the current study is to collect scientific data on all branded hyaluronic acid (HA) products in Italy that are in use for intra-articular (IA) injection in osteoarthritis (OA) compared with that reported in the leaflet. METHODS An extensive literature research was performed for all articles reporting data on the IA use of HA in OA. Selected studies were taken into consideration only if they are related to products based on HAs that are currently marketed in Italy with the specific joint indication for IA use in patients affected by OA. RESULTS Sixty-two HA products are marketed in Italy: 30 products are indicated for the knee but only 8 were proved with some efficacy; 9 products were effective for the hip but only 6 had hip indication; 7 products proved to be effective for the shoulder but only 3 had the indication; 5 products proved effective for the ankle but only one had the indication; 6 products were effective for the temporomandibular joint but only 2 had the indication; only 2 proved effective for vertebral facet joints but only 1 had the indication; and 5 products proved effective for the carpometacarpal joint but only 2 had the indication. CONCLUSIONS There are only a few products with some evidences, while the majority of products remain without proof. Clinicians and regulators should request postmarketing studies from pharmaceuticals to corroborate with that reported in the leaflet and to gather more data, allowing the clinicians to choose the adequate product for the patient. PMID:27279754

  13. Ankle injuries in basketball players.

    PubMed

    Leanderson, J; Nemeth, G; Eriksson, E

    1993-01-01

    We carried out a retrospective study of the frequency of ankle sprains in basketball players. A questionnaire about previous ankle injuries, time off after such injuries, current ankle problems, personal data, number of practice hours and the use of prophylactic measures was sent out to 102 basketball players in a second division league in Sweden. Ninety-six players answered. 92% of them had suffered an ankle sprain while playing basketball, and of these 83% reported repeated sprains of one ankle. In the last two seasons, 78% of the players had injured at least one ankle. The injury frequency in the investigation was 5.5 ankle injuries per 1000 activity hours. 22% of the players used some kind of prophylactic support of their ankle joints. Because of the great number of ankle sprains and the disability in terms of time away from sports that they cause, prevention of these injuries is essential.

  14. Understanding acute ankle ligamentous sprain injury in sports

    PubMed Central

    Fong, Daniel TP; Chan, Yue-Yan; Mok, Kam-Ming; Yung, Patrick SH; Chan, Kai-Ming

    2009-01-01

    be used as it results in joint stiffness, muscle atrophy and loss of proprioception. Traditional Chinese medicine such as herbs, massage and acupuncture were well applied in China in managing sports injuries, and was reported to be effective in relieving pain, reducing swelling and edema, and restoring normal ankle function. Finally, the best practice of sports medicine would be to prevent the injury. Different previous approaches, including designing prophylactice devices, introducing functional interventions, as well as change of games rules were highlighted. This paper allows the readers to catch up with the previous researches on ankle sprain injury, and facilitate the future research idea on sport-related ankle sprain injury. PMID:19640309

  15. The effect of varying the plantarflexion resistance of an ankle-foot orthosis on knee joint kinematics in patients with stroke.

    PubMed

    Kobayashi, Toshiki; Leung, Aaron K L; Akazawa, Yasushi; Hutchins, Stephen W

    2013-03-01

    Ankle-foot orthoses (AFOs) can improve gait in patients with hemiplegia. However, it is anecdotally known that excessive plantarflexion resistance of an AFO could induce undesired knee flexion at early stance. The aim of this study was to systematically investigate the effect of varying the degrees of plantarflexion resistance of an AFO on knee flexion angles at early stance in five subjects with chronic stroke who demonstrated two clear knee flexion peaks at early stance and swing. Each subject wore an experimental AFO constructed with an oil-damper type ankle joint and was instructed to walk at their self-selected walking speed under five plantarflexion resistance conditions. The sagittal plane ankle and knee joint kinematics and gait speed were analyzed using a 3-D Motion Analysis System. A number of significant differences (P<0.005) in maximum knee flexion angles at early stance amongst different plantarflexion resistance conditions were revealed. The knee flexion angle was 23.80 (3.25) degrees under the free hinge joint condition (condition 1), while that was 26.09 (3.79) degrees under the largest resistance condition (condition 5). It was therefore demonstrated that increasing the plantarflexion resistance of an AFO would induce more knee flexion at early stance phase in patients with stroke.

  16. The Independent and Joint Association of Blood Pressure, Serum Total Homocysteine, and Fasting Serum Glucose Levels With Brachial-Ankle Pulse Wave Velocity in Chinese Hypertensive Adults.

    PubMed

    Liu, Xiaoyun; Sun, Ningling; Yu, Tao; Fan, Fangfang; Zheng, Meili; Qian, Geng; Wang, Binyan; Wang, Yu; Tang, Genfu; Li, Jianping; Qin, Xianhui; Hou, Fanfan; Xu, Xiping; Yang, Xinchun; Chen, Yundai; Wang, Xiaobin; Huo, Yong

    2016-09-28

    This study aimed to investigate the independent and joint association of blood pressure (BP), homocysteine (Hcy), and fasting blood glucose (FBG) levels with brachial-ankle pulse wave velocity (baPWV, a measure of arterial stiffness) in Chinese hypertensive adults.The analyses included 3967 participants whose BP, Hcy, FBG, and baPWV were measured along with other covariates. Systolic BP (SBP) was analyzed as 3 categories (SBP < 160 mmHg; 160 to 179 mmHg; ≥ 180 mmHg); Hcy as 3 categories (< 10 μmol/L; 10 to 14.9 μmol/L; ≥ 15.0 μmol/L) and FBG: normal (FBG < 5.6 mmol/L), impaired (5.6 mmol/L ≤ FBG < 7.0 mmol/L), and diabetes mellitus (FBG ≥ 7.0 mmol/L). We performed linear regression analyses to evaluate their associations with baPWV with adjustment for covariables.When analyzed individually, BP, Hcy, and FBG were each associated with baPWV. When BP and FBG were analyzed jointly, the highest baPWV value (mean ± SD: 2227 ± 466 cm/s) was observed in participants with FBG ≥ 7.0 mmol/L and SBP ≥ 180 mmHg (β = 432.5, P < 0.001), and the lowest baPWV value (mean ± SD: 1692 ± 289 cm/s) was seen in participants with NFG and SBP < 160 mmHg. When Hcy and FBG were analyzed jointly, the highest baPWV value (2072 ± 480 cm/s) was observed in participants with FBG ≥ 7.0 mmol/L and Hcy ≥ 15.0 μmol/L (β = 167.6, P < 0.001), while the lowest baPWV value (mean ± SD: 1773 ± 334 cm/s) was observed in participants with NFG and Hcy < 10 μmol/L.In Chinese hypertensive adults, SBP, Hcy, and FBG are individually and jointly associated with baPWV.Our findings underscore the importance of identifying individuals with multiple risk factors of baPWV including high SBP, FBG, and Hcy.

  17. Modelling the Shear Behaviour of Rock Joints with Asperity Damage Under Constant Normal Stiffness

    NASA Astrophysics Data System (ADS)

    Indraratna, Buddhima; Thirukumaran, Sivanathan; Brown, E. T.; Zhu, Song-Ping

    2015-01-01

    The shear behaviour of a rough rock joint depends largely on the surface properties of the joint, as well as the boundary conditions applied across the joint interface. This paper proposes a new analytical model to describe the complete shear behaviour of rough joints under constant normal stiffness (CNS) boundary conditions by incorporating the effect of damage to asperities. In particular, the effects of initial normal stress levels and joint surface roughness on the shear behaviour of joints under CNS conditions were studied, and the analytical model was validated through experimental results. Finally, the practical application of the model to a jointed rock slope stability analysis is presented.

  18. The Very Large G-Protein-Coupled Receptor VLGR1: A Component of the Ankle Link Complex Required for the Normal Development of Auditory Hair Bundles

    PubMed Central

    McGee, JoAnn; Goodyear, Richard J.; McMillan, D. Randy; Stauffer, Eric A.; Holt, Jeffrey R.; Locke, Kirsten G.; Birch, David G.; Legan, P. Kevin; White, Perrin C.; Walsh, Edward J.; Richardson, Guy P.

    2009-01-01

    Sensory hair bundles in the inner ear are composed of stereocilia that can be interconnected by a variety of different link types, including tip links, horizontal top connectors, shaft connectors, and ankle links. The ankle link antigen is an epitope specifically associated with ankle links and the calycal processes of photoreceptors in chicks. Mass spectrometry and immunoblotting were used to identify this antigen as the avian ortholog of the very large G-protein-coupled receptor VLGR1, the product of the Usher syndrome USH2C (Mass1) locus. Like ankle links, Vlgr1 is expressed transiently around the base of developing hair bundles in mice. Ankle links fail to form in the cochleae of mice carrying a targeted mutation in Vlgr1 (Vlgr1/del7TM), and the bundles become disorganized just after birth. FM1-43 [N-(3-triethylammonium)propyl)-4-(4-(dibutylamino)styryl) pyridinium dibromide] dye loading and whole-cell recordings indicate mechanotransduction is impaired in cochlear, but not vestibular, hair cells of early postnatal Vlgr1/del7TM mutant mice. Auditory brainstem recordings and distortion product measurements indicate that these mice are severely deaf by the third week of life. Hair cells from the basal half of the cochlea are lost in 2-month-old Vlgr1/del7TM mice, and retinal function is mildly abnormal in aged mutants. Our results indicate that Vlgr1 is required for formation of the ankle link complex and the normal development of cochlear hair bundles. PMID:16775142

  19. Adaptive sports ankle prosthetics. Interview by Sarah A. Curran.

    PubMed

    Lyle, David K

    2012-09-01

    Participating in sport at all levels is gaining a dedicated following and this is also apparent in individuals with an amputation. Currently, there is a wide variety of ankle prostheses available which attempt to provide function, control, and comfort, as well as good aesthetic appeal. Participation in sport, however, increases the demands placed upon ankle prostheses. This can compromise function and performance, and constrain the opportunities of participation in various outdoor and water sports. In acknowledging this limitation and the need to develop more versatile ankle prostheses, this article introduces the evolution of a prototype ankle prosthesis referred to as "Adaptive Sports Ankle." The ankle prosthesis, which is compatible with any foot pyramid adapter, offers the same range of motion as the normal human ankle joint and is made up of components that are chemical and corrosion resistant. These design features that are specifically created to accommodate below-the-knee amputees provide an ideal prosthesis for those wishing to lead an active lifestyle and participate in aquatic (i.e. swimming, surfing, and scuba diving), snowboarding, and equestrian activities. Although it is acknowledged that there is a need to establish research on the Adaptive Sports Ankle, its introduction to the market will enhance and expand opportunities of those individuals with a lower limb amputation to lead an active and healthy lifestyle.

  20. Joint attention studies in normal and autistic children using NIRS

    NASA Astrophysics Data System (ADS)

    Chaudhary, Ujwal; Hall, Michael; Gutierrez, Anibal; Messinger, Daniel; Rey, Gustavo; Godavarty, Anuradha

    2011-03-01

    Autism is a socio-communication brain development disorder. It is marked by degeneration in the ability to respond to joint attention skill task, from as early as 12 to 18 months of age. This trait is used to distinguish autistic from nonautistic. In this study Near infrared spectroscopy (NIRS) is being applied for the first time to study the difference in activation and connectivity in the frontal cortex of typically developing (TD) and autistic children between 4-8 years of age in response to joint attention task. The optical measurements are acquired in real time from frontal cortex using Imagent (ISS Inc.) - a frequency domain based NIRS system in response to video clips which engenders a feeling of joint attention experience in the subjects. A block design consisting of 5 blocks of following sequence 30 sec joint attention clip (J), 30 sec non-joint attention clip (NJ) and 30 sec rest condition is used. Preliminary results from TD child shows difference in brain activation (in terms of oxy-hemoglobin, HbO) during joint attention interaction compared to the nonjoint interaction and rest. Similar activation study did not reveal significant differences in HbO across the stimuli in, unlike in an autistic child. Extensive studies are carried out to validate the initial observations from both brain activation as well as connectivity analysis. The result has significant implication for research in neural pathways associated with autism that can be mapped using NIRS.

  1. [The potential of the modern methods for clinical diagnostics applied in the forensic medical assessment of functional disturbances of the ankle joint in the case of its injury].

    PubMed

    Khabova, Z S; Fetisov, V A

    2012-01-01

    The present paper is focused on the problems of clinical diagnostics of the functional disturbances in the locomotor apparatus as exemplified by the injuries to the ankle joint. The results of analysis of the entire range of up-to-date diagnostic tools for the purpose suggest the necessity of revision of obsolete methodological principles still adopted in forensic medicine as regards the problem being condidered. It is proposed based on the recent progress achieved by the specialists in traumatology, orthopedics, medicosocial expertise, and the related areas that a forensic medical expert should not confine oneself to the consideration of the sole criterion, such as "the range of articular movements", for the estimation of the severity of harm to health in the patients presenting with a joint injury.

  2. An exoskeleton using controlled energy storage and release to aid ankle propulsion.

    PubMed

    Wiggin, M Bruce; Sawicki, Gregory S; Collins, Steven H

    2011-01-01

    Symmetric ankle propulsion is the cornerstone of efficient human walking. The ankle plantar flexors provide the majority of the mechanical work for the step-to-step transition and much of this work is delivered via elastic recoil from the Achilles' tendon - making it highly efficient. Even though the plantar flexors play a central role in propulsion, body-weight support and swing initiation during walking, very few assistive devices have focused on aiding ankle plantarflexion. Our goal was to develop a portable ankle exoskeleton taking inspiration from the passive elastic mechanisms at play in the human triceps surae-Achilles' tendon complex during walking. The challenge was to use parallel springs to provide ankle joint mechanical assistance during stance phase but allow free ankle rotation during swing phase. To do this we developed a novel `smart-clutch' that can engage and disengage a parallel spring based only on ankle kinematic state. The system is purely passive - containing no motors, electronics or external power supply. This `energy-neutral' ankle exoskeleton could be used to restore symmetry and reduce metabolic energy expenditure of walking in populations with weak ankle plantar flexors (e.g. stroke, spinal cord injury, normal aging).

  3. Normalization of ground reaction forces, joint moments, and free moments in human locomotion.

    PubMed

    Wannop, John W; Worobets, Jay T; Stefanyshyn, Darren J

    2012-12-01

    Authors who report ground reaction force (GRF), free moment (FM), and resultant joint moments usually normalize these variables by division normalization. Normalization parameters include body weight (BW), body weight x height (BWH), and body weight x leg length (BWL). The purpose of this study was to explore the appropriateness of division normalization, power curve normalization, and offset normalization on peak GRF, FM, and resultant joint moments. Kinematic and kinetic data were collected on 98 subjects who walked at 1.2 and 1.8 m/s and ran at 3.4 and 4.0 m/s. Linear curves were best fit to the data, and regression analyses performed to test the significance of the correlations. It was found that the relationship between peak force and BW, as well as joint moments and BW, BWH, and BWL, were not always linear. After division normalization, significant correlations were still found. Power curve and offset normalization, however, were effective at normalizing all variables; therefore, when attempting to normalize GRF and joint moments, perhaps nonlinear or offset methods should be implemented. PMID:23348130

  4. Ultrasound of the elbow: Examination techniques and US appearance of the normal and pathologic joint.

    PubMed

    Draghi, F; Danesino, G M; de Gautard, R; Bianchi, S

    2007-06-01

    Ultrasound studies are frequently requested for the work-up of patients with local elbow pain, which is generally caused by overuse syndromes, trauma, inflammatory diseases, or neuropathies. The technique used to examine this joint will vary to some extent depending on the precise location of the pain and other clinical findings. The aim of this article is to describe the standard technique used for elbow ultrasound, the normal anatomy of the joint, and the appearance on ultrasound of normal elbow anatomy and the alterations associated with some of the more common disorders affecting this joint.

  5. Reliability of sagittal plane hip, knee, and ankle joint angles from a single frame of video data using the GAITRite camera system.

    PubMed

    Ross, Sandy A; Rice, Clinton; Von Behren, Kristyn; Meyer, April; Alexander, Rachel; Murfin, Scott

    2015-01-01

    The purpose of this study was to establish intra-rater, intra-session, and inter-rater, reliability of sagittal plane hip, knee, and ankle angles with and without reflective markers using the GAITRite walkway and single video camera between student physical therapists and an experienced physical therapist. This study included thirty-two healthy participants age 20-59, stratified by age and gender. Participants performed three successful walks with and without markers applied to anatomical landmarks. GAITRite software was used to digitize sagittal hip, knee, and ankle angles at two phases of gait: (1) initial contact; and (2) mid-stance. Intra-rater reliability was more consistent for the experienced physical therapist, regardless of joint or phase of gait. Intra-session reliability was variable, the experienced physical therapist showed moderate to high reliability (intra-class correlation coefficient (ICC) = 0.50-0.89) and the student physical therapist showed very poor to high reliability (ICC = 0.07-0.85). Inter-rater reliability was highest during mid-stance at the knee with markers (ICC = 0.86) and lowest during mid-stance at the hip without markers (ICC = 0.25). Reliability of a single camera system, especially at the knee joint shows promise. Depending on the specific type of reliability, error can be attributed to the testers (e.g. lack of digitization practice and marker placement), participants (e.g. loose fitting clothing) and camera systems (e.g. frame rate and resolution). However, until the camera technology can be upgraded to a higher frame rate and resolution, and the software can be linked to the GAITRite walkway, the clinical utility for pre/post measures is limited.

  6. Cutaneous mechanisms of isometric ankle force control.

    PubMed

    Choi, Julia T; Lundbye-Jensen, Jesper; Leukel, Christian; Nielsen, Jens Bo

    2013-07-01

    The sense of force is critical in the control of movement and posture. Multiple factors influence our perception of exerted force, including inputs from cutaneous afferents, muscle afferents and central commands. Here, we studied the influence of cutaneous feedback on the control of ankle force output. We used repetitive electrical stimulation of the superficial peroneal (foot dorsum) and medial plantar nerves (foot sole) to disrupt cutaneous afferent input in 8 healthy subjects. We measured the effects of repetitive nerve stimulation on (1) tactile thresholds, (2) performance in an ankle force-matching and (3) an ankle position-matching task. Additional force-matching experiments were done to compare the effects of transient versus continuous stimulation in 6 subjects and to determine the effects of foot anesthesia using lidocaine in another 6 subjects. The results showed that stimulation decreased cutaneous sensory function as evidenced by increased touch threshold. Absolute dorsiflexion force error increased without visual feedback during peroneal nerve stimulation. This was not a general effect of stimulation because force error did not increase during plantar nerve stimulation. The effects of transient stimulation on force error were greater when compared to continuous stimulation and lidocaine injection. Position-matching performance was unaffected by peroneal nerve or plantar nerve stimulation. Our results show that cutaneous feedback plays a role in the control of force output at the ankle joint. Understanding how the nervous system normally uses cutaneous feedback in motor control will help us identify which functional aspects are impaired in aging and neurological diseases.

  7. Ankle Sprains.

    PubMed

    1986-02-01

    In brief: Ankle sprain is a risk for many athletes, especially those in the jumping sports (eg, volleyball and basketball) as well as football and soccer, where players tend to roll over on the ankle. Lateral sprains occur much more frequently than medial eversion sprains, but the latter are more devastating. In addition to types of sprains, this panel of specialists discussed surgical vs nonsurgical treatment, tape vs brace for support, rehabilitation and exercise, and ways to prevent ankle sprains.

  8. Ankle trauma significantly impairs posture control--a study in basketball players and controls.

    PubMed

    Perrin, P P; Béné, M C; Perrin, C A; Durupt, D

    1997-07-01

    Both ankle and hip movements are used to maintain balance in strategies defined as bottom up and top down models. This suggests that pathological impairment of either of these articulations could modify the parameters of balance control. In order to appreciate the bearing of ankle damage on the proper control of equilibrium, posturographic recordings were compared, in a static and two dynamic tests, between 15 professional national basketball players, with histories of 10 to 15 ankle sprains, and 50 controls. In statokinesigrams obtained with eyes open or closed, center of foot pressure displacements were of similar length (way) between controls and players, while the area covered was increased for the latter and related to the history of ankle trauma. In a toes-up dynamic test (4 degrees, 50 degrees/s) coupled with electromyographic recordings, the short latency response (myotatic reflex in the triceps surae muscle) normalized to one meter body height, was shorter in players without relationship to histories of ankle damage. In a prolonged sinusoidal dynamic test, players with the largest number of ankle trauma showed greater difficulties in maintaining posture control. These data pinpoint the role of ankles in the control of both static and dynamic balance and demonstrate that the role of the hip joints becomes more important (top down strategy) in the case of damaged ankles.

  9. Foot and ankle problems in dancers.

    PubMed

    Kadel, Nancy

    2014-11-01

    The dancer's foot and ankle are subjected to high forces and unusual stresses in training and performance. Injuries are common in dancers, and the foot and ankle are particularly vulnerable. Ankle sprains, ankle impingement syndromes, flexor hallucis longus tendonitis, cuboid subluxation, stress fractures, midfoot injuries, heel pain, and first metatarsophalangeal joint problems including hallux valgus, hallux rigidus, and sesamoid injuries will be reviewed. This article will discuss these common foot and ankle problems in dancers and give typical clinical presentation and diagnostic and treatment recommendations.

  10. Abnormal peripheral circulation in type 2 diabetic patients with normal ankle-brachial index associates with coronary atherosclerosis, large artery stiffness, and peripheral vascular resistance.

    PubMed

    Tsuchiya, Masanobu; Suzuki, Eiji; Egawa, Katsuya; Nishio, Yoshihiko; Maegawa, Hiroshi; Morikawa, Shigehiro; Inubushi, Toshiro; Kashiwagi, Atsunori

    2005-12-01

    We tested the hypothesis that impaired peripheral circulation in diabetes arises from different aspects of vascular abnormalities even when accompanied by a normal ankle-brachial index (ABI>0.9). One hundred fourteen type 2 diabetic patients with normal ABI and 33 age-matched non-diabetic subjects consecutively admitted to our hospital were enrolled. The Agatston coronary artery calcium score (CACS), as a marker of coronary atherosclerosis, was obtained using electron-beam computed tomography. An automatic device was used to measure brachial-ankle pulse wave velocity (baPWV) as an index of arterial distensibility. Total flow volume and resistive index (RI), as a marker of peripheral vascular resistance, at the popliteal artery were evaluated using gated two-dimensional cine-mode phase-contrast magnetic resonance imaging. Diabetic patients had baPWV (P<0.001) and RI (P<0.001) higher than those in the non-diabetic subjects, indicating that those parameters are characteristically altered in diabetic patients. When diabetic patients were grouped into three subgroups according to their levels of total flow volume, those with the lowest range showed the highest log-transformed CACS (P<0.001), baPWV (P<0.001), and RI (P<0.001) among the groups. Total flow volume was negatively correlated with log-transformed CACS (P<0.001), baPWV (P<0.001), and RI (P<0.001). Waveform at the popliteal artery could be clearly separated into systolic and early and late diastolic blood flows, which were negatively correlated with log-transformed CACS (P<0.001), RI (P<0.001), and baPWV (P<0.001), respectively. These results suggest that impaired peripheral circulation in diabetes is attributable to coronary atherosclerosis, large artery stiffness, and peripheral vascular resistance even when ABI is normal.

  11. Ankle Sprains

    MedlinePlus

    ... What's the Treatment for a Sprained Ankle? More Serious Sprains en español Esguinces de tobillo As a field hockey player, Jill was used to twisting her ankle. She'd always been able to walk it off and get back in the game. But one day she stepped on another player's ...

  12. Tibiofemoral angle and its relation to ankle sprain occurrence.

    PubMed

    Pefanis, Nikolaos; Karagounis, Panagiotis; Tsiganos, Georgios; Armenis, Elias; Baltopoulos, Panagiotis

    2009-12-01

    The lack of a normal joint orientation generates translational or shear forces across the joint. These forces can put abnormally high strain on the cartilage and the surrounding capsuloligamentous tissues. Ankle joint structure can affect or be affected by bony malformations of the surrounding areas, including the knee and hip. The aim of the current study is to examine the possible relationship between the tibiofemoral (TFA) angle and other factors (anthropometric characteristics, medical history, and age) on the occurrence of ankle sprains because its value provides useful information for the anatomical alignment of the lower extremity. The study sample consisted of 45 high-level athletes, evenly distributed among 3 sports (basketball, soccer, and volleyball). TFA measurements were made on radiographs. The study lasted 2 years. A logistic regression was used to determine the importance of each factor on the probability in question. A significance level of P = .1 was used. The factors contributing more to an ankle sprain were a previous injury of the same type followed by body mass index (BMI) and age. On the contrary, TFA was proven to be statistically nonsignificant. When the BMI variable was substituted with body inertia propensity, a derived variable, the TFA remained statistically nonsignificant. TFA magnitude does not seem to be a determinant factor that could increase the probability of spraining an ankle.

  13. A three-dimensional mechanical analysis of normal fault evolution and joint development in perturbed stress fields around normal faults

    NASA Astrophysics Data System (ADS)

    Kattenhorn, Simon Allen

    1998-09-01

    This thesis investigates the role of three dimensionality in the evolution of normal fault systems and joint development in perturbed stress fields induced by slipping normal faults. This is accomplished using: (1) 3D numerical models; (2) field observations of fault and joint characteristics; and (3) seismic data interpretations of 3D normal fault geometries. Numerical models that incorporate the contribution of an increasing lithostatic load with increasing depth on fault slip behavior indicate that normal faults are more prone to slip near the top than the bottom. Energy release rates are maximized at the upper tip, suggesting that faults should grow preferentially in an up-dip direction. For the case of laterally segmented faults, mechanical interaction promotes propagation of segments towards each other, which may result in composite fault surfaces that are longer than they are tall, in agreement with documented natural examples. Slipping faults perturb the surrounding stress field. Field relationships in Arches National Park, Utah, suggest that joints grew in the perturbed stress field around the faults. Numerical analyses indicate that joint orientations depend on the location along the fault tipline in 3D, and may range from fault-parallel to fault-perpendicular. In addition, as the ratio of fault-parallel to fault-perpendicular remote stress increases, so too does the distance away from the fault affected by the perturbed field. In relay zones, joints forming at high angles to fault strike are likely to continue propagating away from the fault if the fault-parallel stress approaches, or slightly exceeds, the fault-perpendicular remote stress during fault slip. Multiple slip maxima at the same stratigraphic level on apparently continuous fault surfaces in 3D seismic data attest to initial lateral segmentation. Mechanical interaction and lateral propagation led to linkage of fault segments and the formation of composite faults that are longer than they are

  14. Independent and Joint Effect of Brachial-Ankle Pulse Wave Velocity and Blood Pressure Control on Incident Stroke in Hypertensive Adults.

    PubMed

    Song, Yun; Xu, Benjamin; Xu, Richard; Tung, Renee; Frank, Eric; Tromble, Wayne; Fu, Tong; Zhang, Weiyi; Yu, Tao; Zhang, Chunyan; Fan, Fangfang; Zhang, Yan; Li, Jianping; Bao, Huihui; Cheng, Xiaoshu; Qin, Xianhui; Tang, Genfu; Chen, Yundai; Yang, Tianlun; Sun, Ningling; Li, Xiaoying; Zhao, Lianyou; Hou, Fan Fan; Ge, Junbo; Dong, Qiang; Wang, Binyan; Xu, Xiping; Huo, Yong

    2016-07-01

    Pulse wave velocity (PWV) has been shown to influence the effects of antihypertensive drugs in the prevention of cardiovascular diseases. Data are limited on whether PWV is an independent predictor of stroke above and beyond hypertension control. This longitudinal analysis examined the independent and joint effect of brachial-ankle PWV (baPWV) with hypertension control on the risk of first stroke. This report included 3310 hypertensive adults, a subset of the China Stroke Primary Prevention Trial (CSPPT) with baseline measurements for baPWV. During a median follow-up of 4.5 years, 111 participants developed first stroke. The risk of stroke was higher among participants with baPWV in the highest quartile than among those in the lower quartiles (6.3% versus 2.4%; hazard ratio, 1.66; 95% confidence interval, 1.06-2.60). Similarly, the participants with inadequate hypertension control had a higher risk of stroke than those with adequate control (5.1% versus 1.8%; hazard ratio, 2.32; 95% confidence interval, 1.49-3.61). When baPWV and hypertension control were examined jointly, participants in the highest baPWV quartile and with inadequate hypertension control had the highest risk of stroke compared with their counterparts (7.5% versus 1.3%; hazard ratio, 3.57; 95% confidence interval, 1.88-6.77). There was a significant and independent effect of high baPWV on stroke as shown among participants with adequate hypertension control (4.2% versus 1.3%; hazard ratio, 2.29, 95% confidence interval, 1.09-4.81). In summary, among hypertensive patients, baPWV and hypertension control were found to independently and jointly affect the risk of first stroke. Participants with high baPWV and inadequate hypertension control had the highest risk of stroke compared with other groups. PMID:27217412

  15. Screw-Home Movement of the Tibiofemoral Joint during Normal Gait: Three-Dimensional Analysis

    PubMed Central

    Kim, Ha Yong; Yang, Dae Suk; Jeung, Sang Wook; Choi, Han Gyeol; Choy, Won Sik

    2015-01-01

    Background The purpose of this study was to evaluate the screw-home movement at the tibiofemoral joint during normal gait by utilizing the 3-dimensional motion capture technique. Methods Fifteen young males and fifteen young females (total 60 knee joints) who had no history of musculoskeletal disease or a particular gait problem were included in this study. Two more markers were attached to the subject in addition to the Helen-Hayes marker set. Thus, two virtual planes, femoral coronal plane (Pf) and tibial coronal plane (Pt), were created by Skeletal Builder software. This study measured the 3-dimensional knee joint movement in the sagittal, coronal, and transverse planes of these two virtual planes (Pf and Pt) during normal gait. Results With respect to kinematics and kinetics, both males and females showed normal adult gait patterns, and the mean difference in the temporal gait parameters was not statistically significant (p > 0.05). In the transverse plane, the screw-home movement occurred as expected during the pre-swing phase and the late-swing phase at an angle of about 17°. However, the tibia rotated externally with respect to the femur, rather than internally, while the knee joint started to flex during the loading response (paradoxical screw-home movement), and the angle was 6°. Conclusions Paradoxical screw-home movement may be an important mechanism that provides stability to the knee joint during the remaining stance phase. Obtaining the kinematic values of the knee joint during gait can be useful in diagnosing and treating the pathological knee joints. PMID:26330951

  16. Product Correlation When Original Variables Are Jointly Distributed Multivariate Normal: A Comparison with Sum Correlation

    ERIC Educational Resources Information Center

    Sockloff, Alan L.

    1977-01-01

    Product correlation was studied under the condition that the original variables are jointly distributed multivariate normal with equal coefficients of variation. Product correlation was shown to range between the two extremes of sum correlation and either the value zero or an unfamiliar function of the intercorrelations of the original variables.…

  17. [Reduction of postoperative swelling. Objective measurement of swelling of the upper ankle joint in treatment with serrapeptase-- a prospective study].

    PubMed

    Esch, P M; Gerngross, H; Fabian, A

    1989-02-10

    Using a quantitative standardized procedure, the swelling of the ankle produced by supination trauma was measured. In the 66 patients with fresh rupture of the lateral ligament treated surgically at our Department between December 1986 and April 1987, a prospective study of the effect of serrapeptase (Aniflazym) on post-operative swelling and pain was carried out in 3 randomized groups of patients. In the group receiving the test substance, the swelling had decreased by 50% on the third post-operative day, while in the other two control groups (elevation of the leg, bed rest, with and without the application of ice) no reduction in swelling had occurred at that time. The difference is statistically significant (p = 0.013). Decreasing pain correlated for the most part with the reduction in swelling. Thus, the patients receiving the test substance more rapidly became pain-free than did the control groups. On the basis of these results, serrapeptase would appear to be an effective preparation for the post-operative reduction of swelling, in comparison with the classical conservative measures, for example, the application of ice.

  18. Individual-specific muscle maximum force estimation using ultrasound for ankle joint torque prediction using an EMG-driven Hill-type model.

    PubMed

    de Oliveira, Liliam Fernandes; Menegaldo, Luciano Luporini

    2010-10-19

    EMG-driven models can be used to estimate muscle force in biomechanical systems. Collected and processed EMG readings are used as the input of a dynamic system, which is integrated numerically. This approach requires the definition of a reasonably large set of parameters. Some of these vary widely among subjects, and slight inaccuracies in such parameters can lead to large model output errors. One of these parameters is the maximum voluntary contraction force (F(om)). This paper proposes an approach to find F(om) by estimating muscle physiological cross-sectional area (PCSA) using ultrasound (US), which is multiplied by a realistic value of maximum muscle specific tension. Ultrasound is used to measure muscle thickness, which allows for the determination of muscle volume through regression equations. Soleus, gastrocnemius medialis and gastrocnemius lateralis PCSAs are estimated using published volume proportions among leg muscles, which also requires measurements of muscle fiber length and pennation angle by US. F(om) obtained by this approach and from data widely cited in the literature was used to comparatively test a Hill-type EMG-driven model of the ankle joint. The model uses 3 EMGs (Soleus, gastrocnemius medialis and gastrocnemius lateralis) as inputs with joint torque as the output. The EMG signals were obtained in a series of experiments carried out with 8 adult male subjects, who performed an isometric contraction protocol consisting of 10s step contractions at 20% and 60% of the maximum voluntary contraction level. Isometric torque was simultaneously collected using a dynamometer. A statistically significant reduction in the root mean square error was observed when US-obtained F(om) was used, as compared to F(om) from the literature.

  19. Basketball injuries of the foot and ankle.

    PubMed

    McDermott, E P

    1993-04-01

    Foot and ankle injuries in basketball are discussed in three unrelated categories in this article. This includes a practical differential diagnosis of ankle sprains, acute conditions of the mid and hindfoot, overuse syndromes of nerve entrapment, fascial strain, synovitis, joint subluxation, and inflammation resulting from repetitive stress. The diagnosis and treatment of tendon inflammation of the extrinsic foot musculature is also reviewed.

  20. Comparison of sensitivity coefficients for joint angle trajectory between normal and pathological gait.

    PubMed

    Błażkiewicz, Michalina; Wit, Andrzej

    2012-01-01

    Gait recordings exhibit intra-subject, inter-subject, within-trial and between-trial variability as well as data analysis methods. In medicine, comparison of different measuring method results or quantifying changes due to specific treatment is required. The aim of this study was to compare a group homogeneity with respect to dispersion around the reference curve and to compare waveforms of normal and pathological gait data based on joint angle curves. Data files were tracked using APAS system. Our own model of lower limb was used to calculate the trajectories of joint angles for 5 groups: healthy men, women, children, persons with drop foot and Trendelenburg's sign. Waveform parameterizations, RMS, IAE and correlation coefficients were used to compare joint angles with reference curve. The sample scores obtained in this work provide an important information about closeness in the shape of two curves. Using multiple techniques of data analysis will benefit and give more accurate information.

  1. Arthroscopic Management of Complications Following Total Ankle Replacement.

    PubMed

    Lui, Tun Hing; Roukis, Thomas S

    2015-10-01

    There is great potential of managing the complications of total ankle replacement arthroscopically and endoscopically, and these procedures can be summarized into 3 groups. Group 1 includes procedures of the ankle joint proper with close proximity to the articular components of the total ankle replacement. Group 2 includes procedures of the tibia and talus with close proximity to the nonarticular parts of the total ankle replacement. Group 3 includes procedures that are away from the total ankle replacement. However, these remain master arthroscopist procedures and should be performed by foot and ankle surgeons who perform them with regularity.

  2. Identification and long-term observation of early joint damage by magnetic resonance imaging in clinically asymptomatic joints in patients with haemophilia A or B despite prophylaxis.

    PubMed

    Olivieri, M; Kurnik, K; Pfluger, T; Bidlingmaier, C

    2012-05-01

    Severe haemophilia is associated with recurrent joint bleeds, which can lead to haemophilic arthropathy. Subclinical joint bleeds have also been associated with joint damage detected using magnetic resonance imaging (MRI). We investigated the development of early changes in clinically asymptomatic joints using MRI in haemophilia A or B patients receiving prophylactic therapy. In this single-centre retrospective cohort study, patients with clinical evidence of joint damage in one ankle and one clinically asymptomatic ankle, in which we performed an MRI scan of both ankles in one session, were enrolled. MRI findings were graded using a 4-point scoring system (0 = normal findings and III = severe joint damage). Since 2000, 38 MRIs in 26 patients have been performed. Starting at a median age of 4 years, 23 patients received prophylaxis 2-3 times weekly. On-demand treatment was performed in three patients. Eight patients (31%) presented with an MRI score of 0, 12 (46%) had a score of I, four (15%) had a score of II, and two (8%) had a score of III in the clinically unaffected ankle. The six patients with MRI scores of II and III had started regular prophylaxis between the ages of 2 years and 15 years; none had developed an inhibitor or experienced a clinically evident bleed in the asymptomatic ankle. During our study, five of 26 patients had a worsening of MRI findings without experiencing a joint bleed. Early morphological changes in clinically asymptomatic ankles can be detected using MRI, despite adequate prophylaxis.

  3. Combined Posterior and Anterior Ankle Arthroscopy

    PubMed Central

    Scholten, Peter E.; van Dijk, C. Niek

    2012-01-01

    Treatment of combined anterior and posterior ankle pathology usually consists of either combined anterior and posterior arthrotomies or anterior ankle arthroscopy with an additional posterolateral portal. The first technique bears the risk of complications associated with the extensive exposure, the latter technique provides limited access to the posterior ankle joint. A case is described of combined anterior and posterior arthroscopy, with the patient lying prone and then turned supine, addressing both anterior and posterior ankle pathologies in one tempo. This minimally invasive combined approach allows quick recovery and early return to work and sports activities. PMID:23227391

  4. Biomechanical comparison of frontal plane knee joint moment arms during normal and Tai Chi walking.

    PubMed

    Jagodinsky, Adam; Fox, John; Decoux, Brandi; Weimar, Wendi; Liu, Wei

    2015-09-01

    [Purpose] Medial knee osteoarthritis, a degenerative joint disease, affects adults. The external knee adduction moment, a surrogate knee-loading measure, has clinical implications for knee osteoarthritis patients. Tai Chi is a promising intervention for pain alleviation in knee osteoarthritis; however, the characteristics of external knee adduction moment during Tai Chi have not been established. [Subjects and Methods] During normal and Tai Chi walking, a gait analysis was performed to compare the external knee adduction moment moment-arm characteristics and paired t-tests to compare moment-arm magnitudes. [Results] A significant difference was observed in the average lateral direction of moment-arm magnitude during Tai Chi walking (-0.0239 ± 0.011 m) compared to that during normal walking (-0.0057 ± 0.004 m). No significant difference was found between conditions in average medial direction of moment-arm magnitude (normal walking: 0.0143 ± 0.010 m; Tai Chi walking: 0.0098 ± 0.014 m). [Conclusion] Tai Chi walking produced a larger peak lateral moment-arm value than normal walking during the stance phase, whereas Tai Chi walking and normal walking peak medial moment-arm values were similar, suggesting that medial knee joint loading may be avoided during Tai Chi walking.

  5. Biomechanical comparison of frontal plane knee joint moment arms during normal and Tai Chi walking

    PubMed Central

    Jagodinsky, Adam; Fox, John; Decoux, Brandi; Weimar, Wendi; Liu, Wei

    2015-01-01

    [Purpose] Medial knee osteoarthritis, a degenerative joint disease, affects adults. The external knee adduction moment, a surrogate knee-loading measure, has clinical implications for knee osteoarthritis patients. Tai Chi is a promising intervention for pain alleviation in knee osteoarthritis; however, the characteristics of external knee adduction moment during Tai Chi have not been established. [Subjects and Methods] During normal and Tai Chi walking, a gait analysis was performed to compare the external knee adduction moment moment-arm characteristics and paired t-tests to compare moment-arm magnitudes. [Results] A significant difference was observed in the average lateral direction of moment-arm magnitude during Tai Chi walking (−0.0239 ± 0.011 m) compared to that during normal walking (−0.0057 ± 0.004 m). No significant difference was found between conditions in average medial direction of moment-arm magnitude (normal walking: 0.0143 ± 0.010 m; Tai Chi walking: 0.0098 ± 0.014 m). [Conclusion] Tai Chi walking produced a larger peak lateral moment-arm value than normal walking during the stance phase, whereas Tai Chi walking and normal walking peak medial moment-arm values were similar, suggesting that medial knee joint loading may be avoided during Tai Chi walking. PMID:26504334

  6. Joint Problems

    MedlinePlus

    ... ankles and toes. Other types of arthritis include gout or pseudogout. Sometimes, there is a mechanical problem ... for more information on osteoarthritis, rheumatoid arthritis and gout. How Common are Joint Problems? Osteoarthritis, which affects ...

  7. Imaging of normal and pathologic joint synovium using nonlinear optical microscopy as a potential diagnostic tool

    NASA Astrophysics Data System (ADS)

    Tiwari, Nivedan; Chabra, Sanjay; Mehdi, Sheherbano; Sweet, Paula; Krasieva, Tatiana B.; Pool, Roy; Andrews, Brian; Peavy, George M.

    2010-09-01

    An estimated 1.3 million people in the United States suffer from rheumatoid arthritis (RA). RA causes profound changes in the synovial membrane of joints, and without early diagnosis and intervention, progresses to permanent alterations in joint structure and function. The purpose of this study is to determine if nonlinear optical microscopy (NLOM) can utilize the natural intrinsic fluorescence properties of tissue to generate images that would allow visualization of the structural and cellular composition of fresh, unfixed normal and pathologic synovial tissue. NLOM is performed on rabbit knee joint synovial samples using 730- and 800-nm excitation wavelengths. Less than 30 mW of excitation power delivered with a 40×, 0.8-NA water immersion objective is sufficient for the visualization of synovial structures to a maximum depth of 70 μm without tissue damage. NLOM imaging of normal and pathologic synovial tissue reveals the cellular structure, synoviocytes, adipocytes, collagen, vascular structures, and differential characteristics of inflammatory infiltrates without requiring tissue processing or staining. Further study to evaluate the ability of NLOM to assess the characteristics of pathologic synovial tissue and its potential role for the management of disease is warranted.

  8. Total ankle replacement – surgical treatment and rehabilitation

    PubMed Central

    Krogulec, Zbigniew; Turski, Piotr; Przepiórski, Emil; Małdyk, Paweł; Księżopolska-Orłowska, Krystyna

    2015-01-01

    Functions of the ankle joint are closely connected with the gait and ability to maintain an upright position. Degenerative lesions of the joint directly contribute to postural disorders and greatly restrict propulsion of the foot, thus leading to abnormal gait. Development of total ankle replacement is connected with the use of the method as an efficient treatment of joint injuries and continuation of achievements in hip and knee surgery. The total ankle replacement technique was introduced as an alternative to arthrodesis, i.e. surgical fixation, which made it possible to preserve joint mobility and to improve gait. Total ankle replacement is indicated in post-traumatic degenerative joint disease and joint destruction secondary to rheumatoid arthritis. In this paper, total ankle replacement and various types of currently used endoprostheses are discussed. The authors also describe principles of early postoperative rehabilitation as well as rehabilitation in the outpatient setting. PMID:27407223

  9. Semiparametric Bayesian inference on skew-normal joint modeling of multivariate longitudinal and survival data.

    PubMed

    Tang, An-Min; Tang, Nian-Sheng

    2015-02-28

    We propose a semiparametric multivariate skew-normal joint model for multivariate longitudinal and multivariate survival data. One main feature of the posited model is that we relax the commonly used normality assumption for random effects and within-subject error by using a centered Dirichlet process prior to specify the random effects distribution and using a multivariate skew-normal distribution to specify the within-subject error distribution and model trajectory functions of longitudinal responses semiparametrically. A Bayesian approach is proposed to simultaneously obtain Bayesian estimates of unknown parameters, random effects and nonparametric functions by combining the Gibbs sampler and the Metropolis-Hastings algorithm. Particularly, a Bayesian local influence approach is developed to assess the effect of minor perturbations to within-subject measurement error and random effects. Several simulation studies and an example are presented to illustrate the proposed methodologies. PMID:25404574

  10. Ankle osteoarthritis: etiology, diagnostics, and classification.

    PubMed

    Barg, Alexej; Pagenstert, Geert I; Hügle, Thomas; Gloyer, Marcel; Wiewiorski, Martin; Henninger, Heath B; Valderrabano, Victor

    2013-09-01

    Osteoarthritis (OA) is defined as the syndrome of joint pain and dysfunction caused by substantial joint degeneration. In general, OA is the most common joint disease and is one of the most frequent and symptomatic health problems for middle-aged and older people: OA disables more than 10% of people who are older than 60 years. This article reviews the etiology of ankle OA, and describes the onset and development of posttraumatic ankle OA, the most common form of OA in the tibiotalar joint. Various methods of clinical and radiographic assessment are described in detail.

  11. Sway‐dependent changes in standing ankle stiffness caused by muscle thixotropy

    PubMed Central

    Sakanaka, Tania E.; Lakie, Martin

    2016-01-01

    Key points The passive stiffness of the calf muscles contributes to standing balance, although the properties of muscle tissue are highly labile.We investigated the effect of sway history upon intrinsic ankle stiffness and demonstrated reductions in stiffness of up to 43% during conditions of increased baseline sway.This sway dependence was most apparent when using low amplitude stiffness‐measuring perturbations, and the short‐range stiffness component was smaller during periods of high sway.These characteristics are consistent with the thixotropic properties of the calf muscles causing the observed changes in ankle stiffness.Periods of increased sway impair the passive stabilization of standing, demanding more active neural control of balance. Abstract Quiet standing is achieved through a combination of active and passive mechanisms, consisting of neural control and intrinsic mechanical stiffness of the ankle joint, respectively. The mechanical stiffness is partly determined by the calf muscles. However, the viscoelastic properties of muscle are highly labile, exhibiting a strong dependence on movement history. By measuring the effect of sway history upon ankle stiffness, the present study determines whether this lability has consequences for the passive stabilization of human standing. Ten subjects stood quietly on a rotating platform whose axis was collinear with the ankle joint. Ankle sway was increased by slowly tilting this platform in a random fashion, or decreased by fixing the body to a board. Ankle stiffness was measured by using the same platform to simultaneously apply small, brief perturbations (<0.6 deg; 140 ms) at the same time as the resulting torque response was recorded. The results show that increasing sway reduces ankle stiffness by up to 43% compared to the body‐fixed condition. Normal quiet stance was associated with intermediate values. The effect was most apparent when using smaller perturbation amplitudes to measure stiffness (0

  12. Common fractures and injuries of the ankle and foot: functional anatomy, imaging, classification and management.

    PubMed

    Khan, Wasim; Oragui, Emeka; Akagha, Edwin

    2010-07-01

    The ankle and foot are functionally important and complex joints. Bony fractures and ligamentous injuries are common. In this review paper we will discuss the functional anatomy, imaging, classification and the management of common ankle and foot injuries including ankle fractures, Achilles tendon ruptures, Lisfranc joint injuries, calcaneo fractures and fractures of the metatarsals and phalanges.

  13. Musculoskeletal modelling deconstructs the paradoxical effects of elastic ankle exoskeletons on plantar-flexor mechanics and energetics during hopping

    PubMed Central

    Farris, Dominic James; Hicks, Jennifer L.; Delp, Scott L.; Sawicki, Gregory S.

    2014-01-01

    Experiments have shown that elastic ankle exoskeletons can be used to reduce ankle joint and plantar-flexor muscle loading when hopping in place and, in turn, reduce metabolic energy consumption. However, recent experimental work has shown that such exoskeletons cause less favourable soleus (SO) muscle–tendon mechanics than is observed during normal hopping, which might limit the capacity of the exoskeleton to reduce energy consumption. To directly link plantar-flexor mechanics and energy consumption when hopping in exoskeletons, we used a musculoskeletal model of the human leg and a model of muscle energetics in simulations of muscle–tendon dynamics during hopping with and without elastic ankle exoskeletons. Simulations were driven by experimental electromyograms, joint kinematics and exoskeleton torque taken from previously published data. The data were from seven males who hopped at 2.5 Hz with and without elastic ankle exoskeletons. The energetics model showed that the total rate of metabolic energy consumption by ankle muscles was not significantly reduced by an ankle exoskeleton. This was despite large reductions in plantar-flexor force production (40–50%). The lack of larger metabolic reductions with exoskeletons was attributed to increases in plantar-flexor muscle fibre velocities and a shift to less favourable muscle fibre lengths during active force production. This limited the capacity for plantar-flexors to reduce activation and energy consumption when hopping with exoskeleton assistance. PMID:25278469

  14. The foot and ankle examination.

    PubMed

    Papaliodis, Dean N; Vanushkina, Maria A; Richardson, Nicholas G; DiPreta, John A

    2014-03-01

    Most foot and ankle disorders can be diagnosed after a proper history and clinical examination and can be effectively managed in a primary care setting. It is important to assess the entirety of patient disorders that present as they can be multifactorial in cause. A broad differential should include disorders of bones, joints, muscles, neurovasculature, and surrounding soft tissue structures. Physical examination should be thorough and focused on inspection, palpation, range of motion, and appropriate special tests when applicable. This article highlights some of the salient features of the foot and ankle examination and diagnostic considerations.

  15. Computed and conventional arthrotomography of the glenohumeral joint: normal anatomy and clinical experience

    SciTech Connect

    Deutsch, A.L.; Resnick, D.; Mink, J.H.; Berman, J.L.; Cone, R.O. III; Resnik, C.S.; Danzig, L.; Guerra, J. Jr.

    1984-12-01

    The glenohumeral joint was studied in 25 cadavers and 136 patients using computed arthrotomography (CAT) and conventional arthrotomography (AT) to assess shoulder instability. Cadaver shoulders were injected with air or latex, sectioned with a band saw, and normal articular anatomy outlined. CAT was performed in 81 patients and characterized the glenoid labrum as normal, abnormal, or detached. Hill-Sachs defects were seen in 20 out of 29 patients with anterior labral abnormalities, while bicipital tendon abnormalities were evident on CAT in 6. Of 55 patients who had AT, the status of the labrum was clarified in 13 of the 16 patients who had surgery or arthroscopy. Both methods can characterize the labrum; however, CAT is more comprehensive and appears ideal for both detection of Hill-Sachs defects and imaging the bicipital tendon. CAT requires less technical expertise and radiation than AT and is tolerated better by patients in pain.

  16. Total Ankle Arthroplasty: An Imaging Overview

    PubMed Central

    Kim, Da-Rae; Potter, Hollis G.; Li, Angela E.; Chun, Ka-Young; Jung, Yoon Young; Kim, Jin-Su; Young, Ki-Won

    2016-01-01

    With advances in implant technology, total ankle arthroplasty (TAA) has become an increasingly popular alternative to arthrodesis for the management of end-stage ankle arthritis. However, reports in the literature do not focus on the imaging features of TAA. Through a literature review, we demonstrate basic design features of the current ankle arthroplasty system, and the normal and abnormal postoperative imaging features associated with such devices. Pre- and postoperative evaluations of ankle arthroplasty mainly include radiography; in addition, computed tomography and magnetic resonance imaging provide further characterization of imaging abnormalities. Familiarization with multimodal imaging features of frequent procedural complications at various postoperative intervals is important in radiological practice. PMID:27134529

  17. Total Ankle Arthroplasty: An Imaging Overview.

    PubMed

    Kim, Da-Rae; Choi, Yun Sun; Potter, Hollis G; Li, Angela E; Chun, Ka-Young; Jung, Yoon Young; Kim, Jin-Su; Young, Ki-Won

    2016-01-01

    With advances in implant technology, total ankle arthroplasty (TAA) has become an increasingly popular alternative to arthrodesis for the management of end-stage ankle arthritis. However, reports in the literature do not focus on the imaging features of TAA. Through a literature review, we demonstrate basic design features of the current ankle arthroplasty system, and the normal and abnormal postoperative imaging features associated with such devices. Pre- and postoperative evaluations of ankle arthroplasty mainly include radiography; in addition, computed tomography and magnetic resonance imaging provide further characterization of imaging abnormalities. Familiarization with multimodal imaging features of frequent procedural complications at various postoperative intervals is important in radiological practice.

  18. Influence of ankle plantar flexor muscle architecture and strength on gait in boys with haemophilia in comparison to typically developing children.

    PubMed

    Stephensen, D; Drechsler, W I; Scott, O M

    2014-05-01

    Altered gait patterns, muscle weakness and atrophy have been reported in young boys with severe haemophilia when compared to unaffected peers. The aim of this study was to determine whether lateral gastrocnemius muscle size and architecture influenced biomechanical walking patterns of boys with haemophilia and if these relationships differed from age-matched typically developing boys. Biomechanical function of the knee and ankle during level walking, lateral gastrocnemius anatomical cross-sectional area, thickness, width, fascicle length and pennation angle and ankle plantar flexor muscle strength were recorded in 19 typically developing boys aged 7-12 years and 19 age-matched haemophilic boys with a history of ankle joint bleeding. Associations between gait, strength and architecture were compared using correlations of peak gait values. Haemophilic boys walked with significantly larger (P < 0.05) ankle dorsi flexion angles and knee flexion moments. The ankle plantar flexor muscles of haemophilic boys were significantly weaker and smaller when compared to typically developing peers. In the typically developing boys there was no apparent association between muscle architecture, strength and walking patterns. In haemophilic boys maximum muscle strength and ACSA normalized torque of the ankle plantar flexors together with the muscle width, thickness, fascicle length and angulation (P < 0.05) were associated with motion at the ankle and peak moments at the knee joint. Muscle strength deficits of the ankle plantar flexors and changes in muscle size and architecture may underpin the key biomechanical alterations in walking patterns of haemophilic boys with a history of ankle joint bleeding.

  19. Conversion of ankle autofusion to total ankle replacement using the Salto XT revision prosthesis.

    PubMed

    Williamson, Emilie R C; Demetracopoulos, Constantine A; Ellis, Scott J

    2016-09-01

    Few reports in the literature have described the conversion of a surgically fused ankle to a total ankle replacement. The takedown of an autofusion and conversion to a prosthesis has not been described. We report the case of a patient with severe rheumatoid arthritis with an ankle autofusion fixed in equinus and severe talonavicular arthritis that was converted to ankle replacement using the Salto XT revision system. We describe the reasons why the decision was made to perform total ankle arthroplasty while concomitantly fusing the talonavicular joint, and discuss the rationale of the various surgical treatment options considered. We describe the clinical and radiographic outcomes achieved in this case. At 12 months post-operatively the patient reported significant reduction of pain, increased FAOS scores and had increased ankle range of motion.

  20. Extraarticular Supramalleolar Osteotomy for Managing Varus Ankle Osteoarthritis, Alternatives for Osteotomy: How and Why?

    PubMed

    Lee, Woo-Chun

    2016-03-01

    The supramalleolar osteotomy has been reported to be a joint preserving surgery with good clinical outcome for asymmetric ankle osteoarthritis, especially varus ankle osteoarthritis. Conventional supramalleolar osteotomy of the tibia and fibula creates angulation and translation of the ankle joint without changing the width of the ankle mortise. Distal tibial oblique osteotomy improved the preoperative clinical and radiological parameters; however, mean talar tilt angle did not decrease. Assessment of the ankle arthritis in sagittal, axial, and coronal planes may be helpful to achieve a decrease of the talar tilt in ankle osteoarthritis.

  1. Range of Motion of the Ankle According to Pushing Force, Gender and Knee Position

    PubMed Central

    Cho, Kang Hee; Lee, Hyunkeun

    2016-01-01

    Objective To investigate the difference of range of motion (ROM) of ankle according to pushing force, gender and knee position. Methods One hundred and twenty-eight healthy adults (55 men, 73 women) between the ages of 20 and 51, were included in the study. One examiner measured the passive range of motion (PROM) of ankle by Dualer IQ Inclinometers and Commander Muscle Testing. ROM of ankle dorsiflexion (DF) and plantarflexion (PF) according to change of pushing force and knee position were measured at prone position. Results There was significant correlation between ROM and pushing force, the more pushing force leads the more ROM at ankle DF and ankle PF. Knee flexion of 90° position showed low PF angle and high ankle DF angle, as compared to the at neutral position of knee joint. ROM of ankle DF for female was greater than for male, with no significant difference. ROM of ankle PF for female was greater than male regardless of the pushing force. Conclusion To our knowledge, this is the first study to assess the relationship between pushing force and ROM of ankle joint. There was significant correlation between ROM of ankle and pushing force. ROM of ankle PF for female estimated greater than male regardless of the pushing force and the number of measurement. The ROM of the ankle is measured differently according to the knee joint position. Pushing force, gender and knee joint position are required to be considered when measuring the ROM of ankle joint. PMID:27152277

  2. Ankle impingement syndromes: a review of etiology and related implications.

    PubMed

    Hess, Gregory William

    2011-10-01

    Ankle injuries are common occurrences in athletics involving and requiring extreme ranges of motion. Ankle sprains specifically occur with a 1 in 10,000 person rate in active individuals each day. If trauma is repetitive, the ankle structures have potential to experience secondary injury and dysfunction. Included in this category of dysfunction are both anterior and posterior ankle impingement syndromes where disruption of the bony structures, joint capsule, ligaments, and tendons typically occurs. Ankle impingement is described as ankle pain that occurs during athletic activity, with recurrent, extreme dorsiflexion or plantar flexion with the joint under a load. Ankle impingements can be classified according to what structures become involved both anteriorly and posteriorly. Osseous impingement, soft tissue impingement, impingement of the distal fascicle of anterior inferior tibiofibular ligament, and meniscoid lesions are all documented causes of ankle impingement. These changes tend to be brought about and exacerbated by extreme ranges of motion. Understanding various impingement types will better enable the clinician to prevent, identify, treat, and rehabilitate affected ankles. Acknowledging activities that predispose to ankle impingement syndrome will enhance prevention and recovery processes. Description of ankle impingement etiology and pathology is the objective of the current review.

  3. Magnetic resonance imaging features of the temporomandibular joint in normal dogs.

    PubMed

    Macready, Dawn M; Hecht, Silke; Craig, Linden E; Conklin, Gordon A

    2010-01-01

    Evaluation of the canine temporomandibular joint (TMJ) is important in the clinical diagnosis of animals presenting with dysphagia, malocclusion and jaw pain. In humans, magnetic resonance imaging (MRI) is the modality of choice for evaluation of the TMJ. The objectives of this study were to establish a technical protocol for performing MRI of the canine TMJ and describe the MRI anatomy and appearance of the normal canine TMJ. Ten dogs (one fresh cadaver and nine healthy live dogs) were imaged. MRIs were compared with cadaveric tissue sections. T1-weighted (T1-W) transverse closed-mouth, T1-W sagittal closed-mouth, T1-W sagittal open-mouth, and T2-W sagittal open-mouth sequences were obtained. The condylar process of the mandible and the mandibular fossa of the temporal bone were hyperintense to muscle and isointense to hypointense to fat on T1-W images, mildly hyperintense to muscle on T2-W images, and were frequently heterogeneous. The articular disc was visible in 14/20 (70%) TMJs on T1-W images and 13/20 (65%) TMJs on T2-W images. The articular disc was isointense to hyperintense to muscle on T1-W images and varied from hypointense to hyperintense to muscle on T2-W images. The lateral collateral ligament was not identified in any joint. MRI allows evaluation of the osseous and certain soft tissue structures of the TMJ in dogs. PMID:20806876

  4. Experimental measurement of flexion-extension movement in normal and corpse prosthetic elbow joint.

    PubMed

    TarniŢă, Daniela; TarniŢă, DănuŢ Nicolae

    2016-01-01

    This paper presents a comparative experimental study of flexion-extension movement in healthy elbow and in the prosthetic elbow joint fixed on an original experimental bench. Measurements were carried out in order to validate the functional morphology and a new elbow prosthesis type ball head. The three-dimensional (3D) model and the physical prototype of our experimental bench used to test elbow endoprosthesis at flexion-extension and pronation-supination movements is presented. The measurements were carried out on a group of nine healthy subjects and on the prosthetic corpse elbow, the experimental data being obtained for flexion-extension movement cycles. Experimental data for the two different flexion-extension tests for the nine subjects and for the corpse prosthetic elbow were acquired using SimiMotion video system. Experimental data were processed statistically. The corresponding graphs were obtained for all subjects in the experimental group, and for corpse prosthetic elbow for both flexion-extension tests. The statistical analysis has proved that the flexion angles of healthy elbows were significantly close to the values measured at the prosthetic elbow fixed on the experimental bench. The studied elbow prosthesis manages to re-establish the mobility for the elbow joint as close to the normal one. PMID:27151700

  5. Foot and Ankle Injuries in Runners.

    PubMed

    Tenforde, Adam S; Yin, Amy; Hunt, Kenneth J

    2016-02-01

    Foot and ankle injuries account for nearly one-third of running injuries. Achilles tendinopathy, plantar fasciopathy, and ankle sprains are 3 of the most common types of injuries sustained during training. Other common injuries include other tendinopathies of the foot and ankle, bone stress injuries, nerve conditions including neuromas, and joint disease including osteoarthritis. This review provides an evidence-based framework for the evaluation and optimal management of these conditions to ensure safe return to running participation and reduce risk for future injury. PMID:26616180

  6. Diagnosis and treatment of chronic ankle pain.

    PubMed

    Wukich, Dane K; Tuason, Dominick A

    2011-01-01

    The differential diagnosis for chronic ankle pain is quite broad. Ankle pain can be caused by intra-articular or extra-articular pathology and may be a result of a traumatic or nontraumatic event. A detailed patient history and physical examination, coupled with judicious selection of the appropriate imaging modalities, are vital in making an accurate diagnosis and providing effective treatment. Chronic ankle pain can affect all age groups, ranging from young athletes to elderly patients with degenerative joint and soft-tissue disorders. It has been estimated that 23,000 ankle sprains occur each day in the United States, representing approximately 1 sprain per 10,000 people per day. Because nearly one in five ankle injuries result in chronic symptoms, orthopaedic surgeons are likely to see patients with chronic ankle pain. Many patients with chronic ankle pain do not recall any history of trauma. Reviewing the management of the various disorders that can cause chronic ankle pain will help orthopaedic surgeons provide the best treatment for their patients. PMID:21553785

  7. Ankle moment generation and maximum-effort curved sprinting performance.

    PubMed

    Luo, Geng; Stefanyshyn, Darren

    2012-11-15

    Turning at high speed along acute curves is crucial for athletic performance. One determinant of curved sprinting speed is the ground reaction force that can be created by the supporting limb; the moment generated at the ankle joint may influence such force generation. Body lean associated with curved sprints positions the ankle joints in extreme in-/eversion, and may hinder the ankle moment generation. To examine the influence of ankle moment generation on curved sprinting performance, 17 male subjects performed maximum-effort curved sprints in footwear with and without a wedge. The wedged footwear was constructed with the intention to align the ankle joints closer to their neutral frontal-plane configuration during counter-clockwise curved sprints so greater joint moments might be generated. We found, with the wedged footwear, the average eversion angle of the inside leg ankle was reduced, and the plantarflexion moment generation increased significantly. Meanwhile, the knee extension moment remained unchanged. With the wedged footwear, stance-average centripetal ground reaction force increased significantly while no difference in the vertical ground reaction force was detected. The subjects created a greater centripetal ground reaction impulse in the wedged footwear despite a shortened stance phase when compared to the control. Stance-average curved sprinting speed improved by 4.3% with the wedged footwear. The changes in ankle moment and curved sprinting speed observed in the current study supports the notion that the moment generation at the ankle joint may be a performance constraint for curved sprinting. PMID:23022207

  8. Development of an efficient rehabilitation exercise program for functional recovery in chronic ankle instability.

    PubMed

    Kim, Kewwan; Jeon, Kyoungkyu

    2016-05-01

    [Purpose] The aim of the present study was to construct an integrated rehabilitation exercise program to prevent chronic pain and improve motor ability in cases of ankle injury and re-injury. [Subjects and Methods] Twenty-six male soccer players who required functional strength exercises due to repeated ankle injury were the subjects. A 12-week rehabilitation exercise program was constructed with the aim of improving muscle strength in the ankle and dynamic coordination of the lower limb. Muscle strength and dynamic coordination were evaluated using the Y Balance Test, and isokinetic muscle strength of ankle dorsiflexion, plantarflexion, inversion, and eversion were measured before and after the 12-week program. [Results] Following 12 weeks of rehabilitation exercise, there were statistically significant improvements in the ratios of dorsiflexor strength to plantarflexor strength, eversion strength, and inversion strength on the left side. The other variables showed no significant changes. [Conclusion] The rehabilitation exercise program for chronic ankle instability helped to reduce pain, and to restore normal joint range of motion, muscle strength and endurance, and functional ability. Active protocols to improve complex functions need to be developed to complement these results. PMID:27313347

  9. Development of an efficient rehabilitation exercise program for functional recovery in chronic ankle instability

    PubMed Central

    Kim, Kewwan; Jeon, Kyoungkyu

    2016-01-01

    [Purpose] The aim of the present study was to construct an integrated rehabilitation exercise program to prevent chronic pain and improve motor ability in cases of ankle injury and re-injury. [Subjects and Methods] Twenty-six male soccer players who required functional strength exercises due to repeated ankle injury were the subjects. A 12-week rehabilitation exercise program was constructed with the aim of improving muscle strength in the ankle and dynamic coordination of the lower limb. Muscle strength and dynamic coordination were evaluated using the Y Balance Test, and isokinetic muscle strength of ankle dorsiflexion, plantarflexion, inversion, and eversion were measured before and after the 12-week program. [Results] Following 12 weeks of rehabilitation exercise, there were statistically significant improvements in the ratios of dorsiflexor strength to plantarflexor strength, eversion strength, and inversion strength on the left side. The other variables showed no significant changes. [Conclusion] The rehabilitation exercise program for chronic ankle instability helped to reduce pain, and to restore normal joint range of motion, muscle strength and endurance, and functional ability. Active protocols to improve complex functions need to be developed to complement these results. PMID:27313347

  10. Development of an efficient rehabilitation exercise program for functional recovery in chronic ankle instability.

    PubMed

    Kim, Kewwan; Jeon, Kyoungkyu

    2016-05-01

    [Purpose] The aim of the present study was to construct an integrated rehabilitation exercise program to prevent chronic pain and improve motor ability in cases of ankle injury and re-injury. [Subjects and Methods] Twenty-six male soccer players who required functional strength exercises due to repeated ankle injury were the subjects. A 12-week rehabilitation exercise program was constructed with the aim of improving muscle strength in the ankle and dynamic coordination of the lower limb. Muscle strength and dynamic coordination were evaluated using the Y Balance Test, and isokinetic muscle strength of ankle dorsiflexion, plantarflexion, inversion, and eversion were measured before and after the 12-week program. [Results] Following 12 weeks of rehabilitation exercise, there were statistically significant improvements in the ratios of dorsiflexor strength to plantarflexor strength, eversion strength, and inversion strength on the left side. The other variables showed no significant changes. [Conclusion] The rehabilitation exercise program for chronic ankle instability helped to reduce pain, and to restore normal joint range of motion, muscle strength and endurance, and functional ability. Active protocols to improve complex functions need to be developed to complement these results.

  11. Unsupported standing with minimized ankle muscle fatigue.

    PubMed

    Mihelj, Matjaz; Munih, Marko

    2004-08-01

    In the past, limited unsupported standing has been restored in patients with thoracic spinal cord injury through open-loop functional electrical stimulation of paralyzed knee extensor muscles and the support of intact arm musculature. Here an optimal control system for paralyzed ankle muscles was designed that enables the subject to stand without hand support in a sagittal plane. The paraplegic subject was conceptualized as an underactuated double inverted pendulum structure with an active degree of freedom in the upper trunk and a passive degree of freedom in the paralyzed ankle joints. Control system design is based on the minimization of a cost function that estimates the effort of ankle joint muscles via observation of the ground reaction force position, relative to ankle joint axis. Furthermore, such a control system integrates voluntary upper trunk activity and artificial control of ankle joint muscles, resulting in a robust standing posture. Figures are shown for the initial simulation study, followed by disturbance tests on an intact volunteer and several laboratory trials with a paraplegic person. Benefits of the presented methodology are prolonged standing sessions and in the fact that the subject is able to maintain voluntary control over upper body orientation in space, enabling simple functional standing. PMID:15311817

  12. Unsupported standing with minimized ankle muscle fatigue.

    PubMed

    Mihelj, Matjaz; Munih, Marko

    2004-08-01

    In the past, limited unsupported standing has been restored in patients with thoracic spinal cord injury through open-loop functional electrical stimulation of paralyzed knee extensor muscles and the support of intact arm musculature. Here an optimal control system for paralyzed ankle muscles was designed that enables the subject to stand without hand support in a sagittal plane. The paraplegic subject was conceptualized as an underactuated double inverted pendulum structure with an active degree of freedom in the upper trunk and a passive degree of freedom in the paralyzed ankle joints. Control system design is based on the minimization of a cost function that estimates the effort of ankle joint muscles via observation of the ground reaction force position, relative to ankle joint axis. Furthermore, such a control system integrates voluntary upper trunk activity and artificial control of ankle joint muscles, resulting in a robust standing posture. Figures are shown for the initial simulation study, followed by disturbance tests on an intact volunteer and several laboratory trials with a paraplegic person. Benefits of the presented methodology are prolonged standing sessions and in the fact that the subject is able to maintain voluntary control over upper body orientation in space, enabling simple functional standing.

  13. Lower extremity thrust and non-thrust joint mobilization for patellofemoral pain syndrome: a case report

    PubMed Central

    Simpson, Brad G; Simon, Corey B

    2014-01-01

    A 40-year old female presented to physical therapy with a one-year history of insidious right anteromedial and anterolateral knee pain. Additionally, the patient had a history of multiple lateral ankle sprains bilaterally, the last sprain occurring on the right ankle 1 year prior to the onset of knee pain. The patient was evaluated and given a physical therapy diagnosis of patellofemoral pain syndrome (PFPS), with associated talocrural and tibiofemoral joint hypomobility limiting ankle dorsiflexion and knee extension, respectively. Treatment included a high-velocity low amplitude thrust manipulation to the talocrural joint, which helped restore normal ankle dorsiflexion range of motion. The patient also received tibiofemoral joint non-thrust manual therapy to regain normal knee extension mobility prior to implementing further functional progression exercises to her home program (HEP). This case report highlights the importance of a detailed evaluation of knee and ankle joint mobility in patients presenting with anterior knee pain. Further, manual physical therapy to the lower extremity was found to be successful in restoring normal movement patterns and pain-free function in a patient with chronic anterior knee pain. PMID:24976753

  14. Improvement in Health State Utility after Sacroiliac Joint Fusion: Comparison to Normal Populations.

    PubMed

    Cher, Daniel J; Polly, David W

    2016-03-01

    Study Design Prospective cohort study. Objective The sacroiliac joint (SIJ) is an important cause of lower back pain. The degree to which minimally invasive surgical fusion of the SIJ improves health state utility has not been previously documented. Methods Health state utility values were calculated using the EuroQOL-5D (EQ-5D) and Short Form-36 (SF-36) at baseline and 6 and 12 months after SIJ fusion surgery in subjects participating in a prospective, multicenter clinical trial (n = 172). Values were compared with individuals who participated in a nationally representative cross-sectional survey (National Health Measurement Study [NHMS], n = 3,844). Health utility values in the SIJ cohort were compared with those of the NMHS participants using both weighted linear regression and calculation of "health quantile" (i.e., percentile of health normalized to the NHMS cohort adjusted for age and gender). Results Baseline health state utility was significantly depressed in SIJ patients compared with normal subjects (SF-6D 0.509 versus 0.789, SF-36 physical component summary 31.7 versus 49.2, SF-36 mental component summary 8.5 versus 53.8, EQ-5D 0.433 versus 0.868; all p < 0.0001 after adjustment for age and gender). In the SIJ cohort, all the measures improved by 6 months postoperatively, and improvements were sustained at 12 months. Baseline health quantile was low (fifth percentile) in the SIJ cohort and improved significantly at follow-up. Conclusions Quality of life is markedly impaired in patients with SIJ pain compared with age- and gender-matched cohorts. SIJ fusion in this cohort resulted in a substantial improvement in health state utility, bringing the population back toward the expected levels of overall health. The quantile approach helps to explain the degree to which health is improved compared with age- and gender-matched cohorts. PMID:26933610

  15. Individual muscle contributions to the axial knee joint contact force during normal walking.

    PubMed

    Sasaki, Kotaro; Neptune, Richard R

    2010-10-19

    Muscles are significant contributors to the high joint forces developed in the knee during human walking. Not only do muscles contribute to the knee joint forces by acting to compress the joint, but they also develop joint forces indirectly through their contributions to the ground reaction forces via dynamic coupling. Thus, muscles can have significant contributions to forces at joints they do not span. However, few studies have investigated how the major lower-limb muscles contribute to the knee joint contact forces during walking. The goal of this study was to use a muscle-actuated forward dynamics simulation of walking to identify how individual muscles contribute to the axial tibio-femoral joint force. The simulation results showed that the vastii muscles are the primary contributors to the axial joint force in early stance while the gastrocnemius is the primary contributor in late stance. The tibio-femoral joint force generated by these muscles was at times greater than the muscle forces themselves. Muscles that do not cross the knee joint (e.g., the gluteus maximus and soleus) also have significant contributions to the tibio-femoral joint force through their contributions to the ground reaction forces. Further, small changes in walking kinematics (e.g., knee flexion angle) can have a significant effect on the magnitude of the knee joint forces. Thus, altering walking mechanics and muscle coordination patterns to utilize muscle groups that perform the same biomechanical function, yet contribute less to the knee joint forces may be an effective way to reduce knee joint loading during walking.

  16. Load compensating reactions to perturbations at wrist joint in normal man

    NASA Technical Reports Server (NTRS)

    Jaeger, R. J.; Agarwell, G. C.; Gottlieb, G. L.

    1981-01-01

    The electromyographic responses to step torque loads were studied in flexors and extensors at the human wrist. Based on temporal bursting patterns and functional behavior, the response was divided into four temporal components. Two early components, the myotatic (30-60 ms) late myotatic (60-120 ms) appears to be reflex response. The third postmyotatic component (120-200 ms) appear to be a triggered reaction, preceeding the fourth, stabilizing component (200-400 ms). A comparison of response at the wrist with similar data at the ankle provides the basis for a generalized classification of the response in various muscles to torque step perturbations.

  17. Arthrometric Measurement of Ankle-Complex Motion: Normative Values

    PubMed Central

    Schwarz, Neil A.; Kovaleski, John E.; Heitman, Robert J.; Gurchiek, Larry R.; Gubler-Hanna, Coral

    2011-01-01

    Abstract Context: Valid and reliable measurements of ankle-complex motion have been reported using the Hollis Ankle Arthrometer. No published normative data of ankle-complex motion obtained from ankle arthrometry are available for use as a reference for clinical decision making. Objective: To describe the distribution variables of ankle-complex motion in uninjured ankles and to establish normative reference values for use in research and to assist in clinical decision making. Design: Descriptive laboratory study. Setting: University research laboratory. Patients or Other Participants: Both ankles of 50 men and 50 women (age = 21.78 ± 2.0 years [range, 19–25 years]) were tested. Intervention(s): Each ankle underwent anteroposterior (AP) and inversion-eversion (I-E) loading using an ankle arthrometer. Main Outcome Measure(s): Recorded anterior, posterior, and total AP displacement (millimeters) at 125 N and inversion, eversion, and total I-E rotation (degrees) at 4 Nm. Results: Women had greater ankle-complex motion for all variables except for posterior displacement. Total AP displacement of the ankle complex was 18.79 ± 4.1 mm for women and 16.70 ± 4.8 mm for men (U = 3742.5, P < .01). Total I-E rotation of the ankle complex was 42.10° ± 9.0° for women and 34.13° ± 10.1° for men (U = 2807, P < .001). All variables were normally distributed except for anterior displacement, inversion rotation, eversion rotation, and total I-E rotation in the women's ankles and eversion rotation in the men's ankles; these variables were skewed positively. Conclusions: Our study increases the available database on ankle-complex motion, and it forms the basis of norm-referenced clinical comparisons and the basis on which quantitative definitions of ankle pathologic conditions can be developed. PMID:21391797

  18. Learning to walk with a robotic ankle exoskeleton.

    PubMed

    Gordon, Keith E; Ferris, Daniel P

    2007-01-01

    We used a lower limb robotic exoskeleton controlled by the wearer's muscle activity to study human locomotor adaptation to disrupted muscular coordination. Ten healthy subjects walked while wearing a pneumatically powered ankle exoskeleton on one limb that effectively increased plantar flexor strength of the soleus muscle. Soleus electromyography amplitude controlled plantar flexion assistance from the exoskeleton in real time. We hypothesized that subjects' gait kinematics would be initially distorted by the added exoskeleton power, but that subjects would reduce soleus muscle recruitment with practice to return to gait kinematics more similar to normal. We also examined the ability of subjects to recall their adapted motor pattern for exoskeleton walking by testing subjects on two separate sessions, 3 days apart. The mechanical power added by the exoskeleton greatly perturbed ankle joint movements at first, causing subjects to walk with significantly increased plantar flexion during stance. With practice, subjects reduced soleus recruitment by approximately 35% and learned to use the exoskeleton to perform almost exclusively positive work about the ankle. Subjects demonstrated the ability to retain the adapted locomotor pattern between testing sessions as evidenced by similar muscle activity, kinematic and kinetic patterns between the end of the first test day and the beginning of the second. These results demonstrate that robotic exoskeletons controlled by muscle activity could be useful tools for testing neural mechanisms of human locomotor adaptation. PMID:17275829

  19. Measurement of passive ankle stiffness in subjects with chronic hemiparesis using a novel ankle robot

    PubMed Central

    Roy, Anindo; Bever, Christopher T.; Forrester, Larry W.; Macko, Richard F.; Hogan, Neville

    2011-01-01

    Our objective in this study was to assess passive mechanical stiffness in the ankle of chronic hemiparetic stroke survivors and to compare it with those of healthy young and older (age-matched) individuals. Given the importance of the ankle during locomotion, an accurate estimate of passive ankle stiffness would be valuable for locomotor rehabilitation, potentially providing a measure of recovery and a quantitative basis to design treatment protocols. Using a novel ankle robot, we characterized passive ankle stiffness both in sagittal and in frontal planes by applying perturbations to the ankle joint over the entire range of motion with subjects in a relaxed state. We found that passive stiffness of the affected ankle joint was significantly higher in chronic stroke survivors than in healthy adults of a similar cohort, both in the sagittal as well as frontal plane of movement, in three out of four directions tested with indistinguishable stiffness values in plantarflexion direction. Our findings are comparable to the literature, thus indicating its plausibility, and, to our knowledge, report for the first time passive stiffness in the frontal plane for persons with chronic stroke and older healthy adults. PMID:21346215

  20. Management of Osseous and Soft-Tissue Ankle Equinus During Total Ankle Replacement.

    PubMed

    Roukis, Thomas S; Simonson, Devin C

    2015-10-01

    Obtaining functional alignment of a total ankle replacement, including physiologic sagittal plane range of motion, is paramount for a successful outcome. This article reviews the literature on techniques available for correction of osseous and soft-tissue equinus at the time of index total ankle replacement. These techniques include anterior tibiotalar joint cheilectomy, posterior superficial muscle compartment lengthening, posterior ankle capsule release, and release of the posterior portions of the medial and lateral collateral ligament complexes. The rationale for these procedures and the operative sequence of events for these procedures are presented.

  1. Ankle replacement - discharge

    MedlinePlus

    Murphy GA. Total ankle arthroplasty. In: Canale ST, Beatty JH, eds. Campbell's Operative Orthopaedics . 12th ed. Philadelphia, PA: Elsevier Mosby; 2012:chap 10. Wexler D, Grosser DM. Ankle arthrtitis. ...

  2. Kinematics and kinetics of normal and planovalgus feet during walking.

    PubMed

    Saraswat, Prabhav; MacWilliams, Bruce A; Davis, Roy B; D'Astous, Jacques L

    2014-01-01

    Planovalgus deformity is prevalent in cerebral palsy patients, but very few studies have quantitatively reported differences between planovalgus and normal foot function. Intersegmental foot kinetics have not been reported in this population. In this study, a three segment (hindfoot, forefoot, hallux) kinematic and kinetic model was applied to typically developing (n=10 subjects, 20 feet) and planovalgus (n=10 subjects, 18 feet) pediatric subjects by two clinicians for each subject. Intra-clinician and inter-clinician repeatability of kinematic variables have been previously reported. Variability of kinetic outcomes (joint moments and power) is reported and found to be equally repeatable in typically developing and planovalgus groups. Kinematic differences in the planovalgus foot including excessive ankle eversion (valgus) and plantarflexion, reduced ankle flexion range of motion, and increased midfoot joint dorsiflexion and pronation reflected the reported pathology. Contrary to clinical expectations no significant difference was observed in midfoot flexion or ankle eversion ranges of motion. Kinetic differences in planovalgus feet compared to typically developing feet included reduced ankle plantarflexion moment, ankle power and midfoot joint power.

  3. Single-joint rapid arm movements in normal subjects and in patients with motor disorders.

    PubMed

    Berardelli, A; Hallett, M; Rothwell, J C; Agostino, R; Manfredi, M; Thompson, P D; Marsden, C D

    1996-04-01

    In normal subjects the execution of single rapid one-joint movements is characterized by an electromyographic (EMG) pattern composed of three discrete bursts of activity; two bursts (first and second agonist bursts, or AG1 and AG2) are present in the agonist muscle separated by an almost complete period of electrical silence. During this pause, another burst (antagonist burst, or ANT) occurs in the antagonist muscle. If a rapid movement is executed during tonic activation of the agonist muscle, tonic activity is inhibited just prior to AG1 onset (agonist inhibition). Similarly, if the movement is performed during tonic activation of the antagonist muscle, such activity is also inhibited prior to AG1 onset (antagonist inhibition). Antagonist inhibition also starts prior to AG1 onset and lasts until ANT onset. A general descriptor of the kinematic features related to the EMG pattern described above is a symmetrical and unimodal velocity profile that is bell-shaped and shows an acceleration time roughly equal to the deceleration time. This holds true for movements performed under low accuracy constraints; as accuracy demands become stricter and stricter, the peak velocity decreases but, as long as the movement is made with one continuous trajectory, the velocity profile remains roughly symmetrical. In general terms, the function of AG1 is to provide the impulsive force to start the movement; the function of ANT is to halt the movement at the desired end-point; and the function of AG2 is to dampen out the oscillations which might occur at the end of the movement. The timing and size of the bursts vary according to the speed and amplitude of the movement. The origin of the EMG pattern is a central programme, but afferent inputs can modulate the voluntary activity. In this paper, we also review the EMG and kinematic abnormalities that are present during the execution of single-joint, rapid arm movements in patients with Parkinson's disease, Huntington's disease, Sydenham

  4. Salvage arthrodesis for failed total ankle arthroplasty

    PubMed Central

    Zürcher, Arthur W

    2010-01-01

    Background and purpose Total ankle arthroplasty (TAA) has gained popularity in recent years. If it fails, however, salvage arthrodesis must be reliable as a rescue procedure. We therefore investigated the clinical, radiographic, and subjective outcome after salvage arthrodesis in a consecutive group of patients, and concentrated on the influence of the method of fixation on union rate and on salvage in inflammatory joint disease. Patients and methods Between 1994 and 2005, salvage arthrodesis was performed on 18 ankles (18 patients). Diagnosis was inflammatory joint disease (IJD) in 15 cases and osteoarthritis (OA) in 3. Tibio-talar fusion was performed in 7 ankles, and tibio-talocalcaneal fusion in 11. Serial radiographs were studied for time to union. Clinical outcome at latest follow-up was measured by the AOFAS score, the foot function index (FFI) and by VAS scores for pain, function, and satisfaction. Results Blade plates were used in 7 ankles (4 IJD, 3 OA); all united. Nonunion developed in 7 of the 11 rheumatic ankles stabilized by other methods. 11 patients (8 fused ankles, 3 nonunions) were available for clinical evaluation. Their mean AOFAS score was 62 and mean overall FFI was 70. VAS score for pain was 20, for function 64, and for satisfaction 74. The scores were similar in united and non-united ankles. Interpretation Blade plate fixation is successful in salvage arthrodesis for failed TAA. A high nonunion rate was found after salvage ankle arthrodesis in IJD with other methods of fixation. Clinical results were fair to good. PMID:20175648

  5. Joint inversion of normal-mode and finite-frequency S-wave data using an irregular tomographic grid

    NASA Astrophysics Data System (ADS)

    Zaroli, Christophe; Lambotte, Sophie; Lévêque, Jean-Jacques

    2015-12-01

    Global-scale tomographic models should aim at satisfying the full seismic spectrum. For this purpose, and to better constrain isotropic 3-D variations of shear velocities in the mantle, we tackle a joint inversion of spheroidal normal-mode structure coefficients and multiple-frequency S-wave delay times. In all previous studies for which normal modes were jointly inverted for, with body and/or surface waves, the mantle was laterally parametrized with uniform basis functions, such as spherical harmonics, equal-area blocks and evenly spaced spherical splines. In particular, spherical harmonics naturally appear when considering the Earth's free oscillations. However, progress towards higher resolution joint tomography requires a movement away from such uniform parametrization to overcome its computational inefficiency to adapt to local variations in resolution. The main goal of this study is to include normal modes into a joint inversion based upon a non-uniform parametrization that is adapted to the spatially varying smallest resolving length of the data. Thus, we perform the first joint inversion of normal-mode and body-wave data using an irregular tomographic grid, optimized according to ray density. We show how to compute the projection of 3-D sensitivity kernels for both data sets onto our parametrization made up of spherical layers spanned with irregular Delaunay triangulations. This approach, computationally efficient, allows us to map into the joint model multiscale structural informations from data including periods in the 10-51 s range for body waves and 332-2134 s for normal modes. Tomographic results are focused on the 400-2110 km depth range, where our data coverage is the most relevant. We discuss the potential of a better resolution where the grid is fine, compared to spherical harmonics up to degree 40, as the number of model parameters is similar. Our joint model seems to contain coherent structural components beyond degree 40, such as those related

  6. Split biceps femoris tendon reconstruction for proximal tibiofibular joint instability.

    PubMed

    Mena, H; Brautigan, B; Johnson, D L

    2001-07-01

    Recurrent instability of the proximal tibiofibular joint is an infrequently diagnosed abnormality. We present a new technique for reconstructing the joint using a split biceps femoris tendon passed through a bone tunnel in both the proximal tibial metaphysis and fibular head. The case report is also presented. The procedure offers an anatomic reconstruction and firm stabilization. It allows normal motion of the proximal tibiofibular joint and preserves the normal mechanics of the ankle. This procedure is an excellent alternative to resection of the fibular head, transarticular arthrodesis, or pseudoarthrosis focus at the fibular head.

  7. Assessment of Ankle Injuries

    ERIC Educational Resources Information Center

    Mai, Nicholas; Cooper, Leslie

    2009-01-01

    School nurses are faced with the challenge of identifying and treating ankle injuries in the school setting. There is little information guiding the assessment and treatment of these children when an injury occurs. It is essential for school nurses to understand ankle anatomy, pathophysiology of the acute ankle injury, general and orthopedic…

  8. The limits of passive motion are variable between and unrelated within normal tibiofemoral joints.

    PubMed

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

    2015-11-01

    Patient-to-patient differences should be accounted for in both clinical evaluations and computational models of knee laxity. Accordingly, the objectives were to determine how variable the laxities are between knees by determining the range of the internal-external (I-E), varus-valgus (V-V), anterior-posterior (A-P), and compression-distraction (C-D) limits of passive motion, and how related the laxities are within a knee by determining whether these limits are correlated with one another. The limits in I-E (± 3 Nm), V-V (± 5 Nm), A-P (± 45 N), and C-D (± 100 N) were measured in 10 normal human cadaveric knees at 0° to 120° flexion in 15° increments using a six degree-of-freedom load application system. The ranges from 15° to 120° flexion of the I-E limits were greater than 3.6°, of the A-P limits were greater than 1.8 mm, and of the varus limits were greater than 1.4°. The ranges from 30° to 120° flexion of the distraction limits were greater than 2.0 mm. Twenty-four of the 28 pair-wise comparisons between the limits had a correlation coefficient less than 0.65. These results demonstrate that a patient-specific approach, including all degrees of freedom of interest, is necessary during clinical evaluations of laxity and when creating and validating computational models of the tibiofemoral joint. PMID:26218329

  9. Effects of normal and abnormal loading conditions on morphogenesis of the prenatal hip joint: application to hip dysplasia

    PubMed Central

    Giorgi, Mario; Carriero, Alessandra; Shefelbine, Sandra J.; Nowlan, Niamh C.

    2015-01-01

    Joint morphogenesis is an important phase of prenatal joint development during which the opposing cartilaginous rudiments acquire their reciprocal and interlocking shapes. At an early stage of development, the prenatal hip joint is formed of a deep acetabular cavity that almost totally encloses the head. By the time of birth, the acetabulum has become shallower and the femoral head has lost substantial sphericity, reducing joint coverage and stability. In this study, we use a dynamic mechanobiological simulation to explore the effects of normal (symmetric), reduced and abnormal (asymmetric) prenatal movements on hip joint shape, to understand their importance for postnatal skeletal malformations such as developmental dysplasia of the hip (DDH). We successfully predict the physiological trends of decreasing sphericity and acetabular coverage of the femoral head during fetal development. We show that a full range of symmetric movements helps to maintain some of the acetabular depth and femoral head sphericity, while reduced or absent movements can lead to decreased sphericity and acetabular coverage of the femoral head. When an abnormal movement pattern was applied, a deformed joint shape was predicted, with an opened asymmetric acetabulum and the onset of a malformed femoral head. This study provides evidence for the importance of fetal movements in the prevention and manifestation of congenital musculoskeletal disorders such as DDH. PMID:26163754

  10. Effects of normal and abnormal loading conditions on morphogenesis of the prenatal hip joint: application to hip dysplasia.

    PubMed

    Giorgi, Mario; Carriero, Alessandra; Shefelbine, Sandra J; Nowlan, Niamh C

    2015-09-18

    Joint morphogenesis is an important phase of prenatal joint development during which the opposing cartilaginous rudiments acquire their reciprocal and interlocking shapes. At an early stage of development, the prenatal hip joint is formed of a deep acetabular cavity that almost totally encloses the head. By the time of birth, the acetabulum has become shallower and the femoral head has lost substantial sphericity, reducing joint coverage and stability. In this study, we use a dynamic mechanobiological simulation to explore the effects of normal (symmetric), reduced and abnormal (asymmetric) prenatal movements on hip joint shape, to understand their importance for postnatal skeletal malformations such as developmental dysplasia of the hip (DDH). We successfully predict the physiological trends of decreasing sphericity and acetabular coverage of the femoral head during fetal development. We show that a full range of symmetric movements helps to maintain some of the acetabular depth and femoral head sphericity, while reduced or absent movements can lead to decreased sphericity and acetabular coverage of the femoral head. When an abnormal movement pattern was applied, a deformed joint shape was predicted, with an opened asymmetric acetabulum and the onset of a malformed femoral head. This study provides evidence for the importance of fetal movements in the prevention and manifestation of congenital musculoskeletal disorders such as DDH. PMID:26163754

  11. Effects of normal and abnormal loading conditions on morphogenesis of the prenatal hip joint: application to hip dysplasia.

    PubMed

    Giorgi, Mario; Carriero, Alessandra; Shefelbine, Sandra J; Nowlan, Niamh C

    2015-09-18

    Joint morphogenesis is an important phase of prenatal joint development during which the opposing cartilaginous rudiments acquire their reciprocal and interlocking shapes. At an early stage of development, the prenatal hip joint is formed of a deep acetabular cavity that almost totally encloses the head. By the time of birth, the acetabulum has become shallower and the femoral head has lost substantial sphericity, reducing joint coverage and stability. In this study, we use a dynamic mechanobiological simulation to explore the effects of normal (symmetric), reduced and abnormal (asymmetric) prenatal movements on hip joint shape, to understand their importance for postnatal skeletal malformations such as developmental dysplasia of the hip (DDH). We successfully predict the physiological trends of decreasing sphericity and acetabular coverage of the femoral head during fetal development. We show that a full range of symmetric movements helps to maintain some of the acetabular depth and femoral head sphericity, while reduced or absent movements can lead to decreased sphericity and acetabular coverage of the femoral head. When an abnormal movement pattern was applied, a deformed joint shape was predicted, with an opened asymmetric acetabulum and the onset of a malformed femoral head. This study provides evidence for the importance of fetal movements in the prevention and manifestation of congenital musculoskeletal disorders such as DDH.

  12. Osteochondral defects in the ankle: why painful?

    PubMed Central

    Reilingh, Mikel L.; Zengerink, Maartje; van Bergen, Christiaan J. A.

    2010-01-01

    Osteochondral defects of the ankle can either heal and remain asymptomatic or progress to deep ankle pain on weight bearing and formation of subchondral bone cysts. The development of a symptomatic OD depends on various factors, including the damage and insufficient repair of the subchondral bone plate. The ankle joint has a high congruency. During loading, compressed cartilage forces its water into the microfractured subchondral bone, leading to a localized high increased flow and pressure of fluid in the subchondral bone. This will result in local osteolysis and can explain the slow development of a subchondral cyst. The pain does not arise from the cartilage lesion, but is most probably caused by repetitive high fluid pressure during walking, which results in stimulation of the highly innervated subchondral bone underneath the cartilage defect. Understanding the natural history of osteochondral defects could lead to the development of strategies for preventing progressive joint damage. PMID:20151110

  13. Dilatant normal faulting in jointed cohesive rocks: insights from physical modeling

    NASA Astrophysics Data System (ADS)

    Kettermann, Michael; von Hagke, Christoph; Urai, Janos

    2016-04-01

    Dilatant faults often form in rocks containing pre-existing joints, but the effects of joints on fault segment linkage and fracture connectivity is not well understood. Studying evolution of dilatancy and influence of fractures on fault development provides insights on geometry of fault zones in brittle rocks and eventually allows for predicting their subsurface appearance. We assess the evolution of dilatant faults in fractured rocks using analogue models with cohesive powder. The upper layer contains pre-formed joint sets, and we vary the angle between joints and a rigid basement fault in our experiments. Analogue models were carried out in a manually driven deformation box (30x28x20 cm) with a 60° dipping pre-defined basement fault and 4.5 cm of displacement. To produce open joints prior to faulting, sheets of paper were mounted in the box to a depth of 5 cm at a spacing of 2.5 cm. Powder was then sieved into the box, embedding the paper almost entirely (column height of 19 cm), and the paper was removed. We tested the influence of different angles between the strike of the basement fault and the joint set (joint fault (JF) angles of 0°, 4°, 8°, 12°, 16°, 20°, and 25°). During deformation we captured structural information by time-lapse photography that allows particle imaging velocimetry analyses (PIV) to detect localized deformation at every increment of displacement. Post-mortem photogrammetry preserves the final 3-dimensional structure of the fault zone. Results show robust structural features in models: damage zone width increases by about 50 % and the number of secondary fractures within this zone by more than 100 % with increasing JF-angle. Interestingly, the map-view area fraction of open gaps increases by only 3%. Secondary joints and fault step-overs are oriented at a high angle to the primary joint orientation. Due to the length of the pre-existing open joints, areas far beyond the fractured regions are connected to the system. In contrast

  14. Normalization.

    ERIC Educational Resources Information Center

    Cuevas, Eduardo J.

    1997-01-01

    Discusses cornerstone of Montessori theory, normalization, which asserts that if a child is placed in an optimum prepared environment where inner impulses match external opportunities, the undeviated self emerges, a being totally in harmony with its surroundings. Makes distinctions regarding normalization, normalized, and normality, indicating how…

  15. Ankle sprains and instability.

    PubMed

    Czajka, Cory M; Tran, Elaine; Cai, Andrew N; DiPreta, John A

    2014-03-01

    Ankle injuries are among the most common injuries presenting to primary care providers and emergency departments and may cause considerable time lost to injury and long-term disability. Inversion injuries about the ankle involve about 25% of all injuries of the musculoskeletal system and 50% of all sports-related injuries. Medial-sided ankle sprains occur less frequently than those on the lateral side. High ankle sprains occur less frequently in the general population, but do occur commonly in collision sports. Providers should apply the Ottawa ankle rules when radiography is indicated and refer fractures and more severe injuries to orthopedic surgery as needed. PMID:24559877

  16. Are there any relationships among ankle proprioception acuity, pre-landing ankle muscle responses, and landing impact in man?

    PubMed

    Fu, Siu Ngor; Hui-Chan, Christina Wan Ying

    2007-05-01

    Proprioceptive input has been suggested to contribute to the pre-landing muscle responses associated with drop-landing, but its precise role has yet to be delineated. This study set out to examine the relationships among ankle proprioception, pre-landing muscle responses, and landing impact on drop-landing in healthy man. Fifteen healthy male basketball players aged 18 to 26 participated in this study. Passive ankle joint repositioning errors were used to examine ankle joint proprioception. Pre-landing EMG responses in the ankle muscles and the impact force on landing were recorded while the players performed self-initiated drops from a height of 30 cm. Results demonstrated that averaged ankle repositioning errors were significantly correlated with the co-contraction indexes between left tibialis anterior and medial gastrocnemius muscles (TA/MG CoI) (r=0.67, p=0.006), and showed a trend towards a relationship with the right TA/MG CoI (r=0.47, p=0.079). TA/MG CoI from both ankles were further related to the magnitude of the total impact force on landing (r=0.54 and 0.53, respectively; p<0.05). We concluded that male basketball players with less accurate ankle joint sense adopted greater co-contraction of ankle dorsiflexors and platarflexors, which was in turn associated with greater impact force at the moment of landing.

  17. Developing a Framework for Ankle Function: A Delphi Study

    PubMed Central

    Snyder, Kelli R.; Evans, Todd A.; Neibert, Peter J.

    2014-01-01

    Context: Addressing clinical outcomes is paramount to providing effective health care, yet there is no consensus regarding the appropriate outcomes to address after ankle injuries. Compounding the problem is the repetitive nature of lateral ankle sprains, referred to as functional (FAI) or chronic (CAI) ankle instability. Although they are commonly used terms in practice and research, FAI and CAI are inconsistently defined and assessed. Objective: To establish definitions of a healthy/normal/noninjured ankle, FAI, and CAI, as well as their characteristics and assessment techniques. Design: Delphi study. Setting: Telephone interviews and electronic surveys. Patients or Other Participants: Sixteen experts representing the fields of ankle function and treatment, ankle research, and outcomes assessment and research were selected as panelists. Data Collection and Analysis: A telephone interview produced feedback regarding the definition of, functional characteristics of, and assessment techniques for a healthy/normal/noninjured ankle, an unhealthy/acutely injured ankle, and FAI/CAI. Those data were compiled, reduced, and returned through electronic surveys and were either included by reaching consensus (80% agreement) or excluded. Results: The definitions of a healthy/normal/noninjured ankle and FAI reached consensus. Experts did not agree on a definition of CAI. Eleven functional characteristics of a healthy/normal/noninjured ankle, 32 functional characteristics of an unhealthy/acutely injured ankle, and 13 characteristics of FAI were agreed upon. Conclusions: Although a consensus was reached regarding the definitions and functional characteristics of a healthy/normal/noninjured ankle and FAI, the experts could only agree on 1 characteristic to include in the FAI definition. Several experts did, however, provide additional comments that reinforced the differences in the interpretation of those concepts. Although the experts could not agree on the definition of CAI, its

  18. Design and Control of an Active Electrical Knee and Ankle Prosthesis

    PubMed Central

    Sup, Frank; Varol, Huseyin Atakan; Mitchell, Jason; Withrow, Thomas; Goldfarb, Michael

    2010-01-01

    This paper presents an overview of the design and control of an electrically powered knee and ankle prosthesis. The prosthesis design incorporates two motor-driven ball screw units to drive the knee and ankle joints. A spring in parallel with the ankle motor unit is employed to decrease the power consumption and increase the torque output for a given motor size. The device’s sensor package includes a custom load cell to measure the sagittal socket interface moment above the knee joint, a custom sensorized foot to measure the ground reaction force at the heel and ball of the foot, and commercial potentiometers and load cells to measure joint positions and torques. A finite-state based impedance control approach, previously developed by the authors, is used and experimental results on level treadmill walking are presented that demonstrate the potential of the device to restore normal gait. The experimental power consumption of the device projects a walking distance of 5.0 km at a speed of 2.8 km/hr with a lithium polymer battery pack. PMID:20648239

  19. Removal of osteoblastoma of the talar neck using standard anterior ankle Arthroscopy:A case report

    PubMed Central

    Duan, Xiao-jun; Yang, Liu

    2016-01-01

    Introduction Osteoblastoma of the talus, a benign tumor, is rare in orthopedics. The choice of treatment is usually open surgery for excision of tumor. Limited data is available concerning arthroscopic approaches. Presentation of case A 36-year-old male patient was evaluated for pain and swelling of the left ankle joint. Based on the findings of physical examination, X-rays and MRI investigations, the tumor was isolated. Standard anterior arthroscopic surgery was performed due to ankle pain. A diagnosis of osteoblastoma of the talar neck was made following the pathological survey. He had no recurrent pain and normal joint mobility 5 years postoperatively during he was regularly followed up. Discussion Osteoblastoma of the talar neck is slowly progressive and it is a palpable painful mass. Open or arthroscopic surgery can be performed. Treatment strategies are decided on according to the tumor's location, extent and size. Some advantages of arthroscopic surgery are wide visualization areas, minimally invasion, low morbidity, no necessity for casting and immobilization, early rehabilitation and quick recovery. Conclusion In conclusion, arthroscopic management can be successful in selected patients with small benign tumor localized to the ankle joint. PMID:27100951

  20. Correlation among Joint Motions Allows Classification of Parkinsonian versus Normal 3D Reaching

    PubMed Central

    Chan, Jacky; Leung, Howard; Poizner, Howard

    2009-01-01

    In this paper, an objective assessment for determining whether a person has Parkinson disease is proposed. This is achieved by analyzing the correlation between joint movements, since Parkinsonian patients often have trouble coordinating different joints in a movement. Thus, the auto-correlation coefficient of single joint movements and the cross-correlation between movements in a pair of joints (hand, wrist, elbow and shoulder) were studied. These features were used to train and provide classification of subjects as having or not having Parkinson's disease using the Least Square Support Vector Machine. Experimental results showed that using either auto-correlation or cross-correlation features for classification provided over 91% correct classification. Using both features together provided better performance (96.0%) than using either feature alone. In addition, the performance of LS-SVM is better than that of Self Organizing Map (SOM) and k-nearest neighbor (KNN) in this case. PMID:19497826

  1. Invariant ankle moment patterns when walking with and without a robotic ankle exoskeleton.

    PubMed

    Kao, Pei-Chun; Lewis, Cara L; Ferris, Daniel P

    2010-01-19

    To guide development of robotic lower limb exoskeletons, it is necessary to understand how humans adapt to powered assistance. The purposes of this study were to quantify joint moments while healthy subjects adapted to a robotic ankle exoskeleton and to determine if the period of motor adaptation is dependent on the magnitude of robotic assistance. The pneumatically powered ankle exoskeleton provided plantar flexor torque controlled by the wearer's soleus electromyography (EMG). Eleven naïve individuals completed two 30-min sessions walking on a split-belt instrumented treadmill at 1.25m/s while wearing the ankle exoskeleton. After two sessions of practice, subjects reduced their soleus EMG activation by approximately 36% and walked with total ankle moment patterns similar to their unassisted gait (r(2)=0.98+/-0.02, THSD, p>0.05). They had substantially different ankle kinematic patterns compared to their unassisted gait (r(2)=0.79+/-0.12, THSD, p<0.05). Not all of the subjects reached a steady-state gait pattern within the two sessions, in contrast to a previous study using a weaker robotic ankle exoskeleton (Gordon and Ferris, 2007). Our results strongly suggest that humans aim for similar joint moment patterns when walking with robotic assistance rather than similar kinematic patterns. In addition, greater robotic assistance provided during initial use results in a longer adaptation process than lesser robotic assistance. PMID:19878952

  2. Invariant ankle moment patterns when walking with and without a robotic ankle exoskeleton.

    PubMed

    Kao, Pei-Chun; Lewis, Cara L; Ferris, Daniel P

    2010-01-19

    To guide development of robotic lower limb exoskeletons, it is necessary to understand how humans adapt to powered assistance. The purposes of this study were to quantify joint moments while healthy subjects adapted to a robotic ankle exoskeleton and to determine if the period of motor adaptation is dependent on the magnitude of robotic assistance. The pneumatically powered ankle exoskeleton provided plantar flexor torque controlled by the wearer's soleus electromyography (EMG). Eleven naïve individuals completed two 30-min sessions walking on a split-belt instrumented treadmill at 1.25m/s while wearing the ankle exoskeleton. After two sessions of practice, subjects reduced their soleus EMG activation by approximately 36% and walked with total ankle moment patterns similar to their unassisted gait (r(2)=0.98+/-0.02, THSD, p>0.05). They had substantially different ankle kinematic patterns compared to their unassisted gait (r(2)=0.79+/-0.12, THSD, p<0.05). Not all of the subjects reached a steady-state gait pattern within the two sessions, in contrast to a previous study using a weaker robotic ankle exoskeleton (Gordon and Ferris, 2007). Our results strongly suggest that humans aim for similar joint moment patterns when walking with robotic assistance rather than similar kinematic patterns. In addition, greater robotic assistance provided during initial use results in a longer adaptation process than lesser robotic assistance.

  3. The sprained ankle.

    PubMed

    Puffer, J C

    2001-01-01

    The sprained ankle is the most common musculoskeletal injury seen by physicians caring for active youngsters and adults. It accounts for approximately one fourth of all sports-related injuries and is commonly seen in athletes participating in basketball, soccer, or football. It has been shown that one third of West Point cadets suffer an ankle sprain during their 4 years at the military academy. While diagnosis and management of the sprained ankle is usually straightforward, several serious injuries can masquerade as an ankle sprain, and it is important for the clinician to recognize these to prevent long-term morbidity. In this article the basic anatomy of the ankle, mechanisms by which the ankle is injured, and the differential diagnosis of the acutely injured ankle are reviewed. Appropriate evaluation of the injured ankle and the criteria that should be utilized for determining the necessity of radiographs are discussed as well as management of the acutely sprained ankle and the role of prevention in reducing the risk of ankle injury.

  4. Determination of the normal arthroscopic anatomy of the femoropatellar and cranial femorotibial joints of cattle

    PubMed Central

    Nichols, Sylvain; Anderson, David E.

    2014-01-01

    The arthroscopic approach and anatomy of the bovine femoropatellar and femorotibial joints are described. A 4-mm diameter, 15-cm long arthroscope with a 30° forward angle view was used. The structures viewed were recorded according to the position of the arthroscope within the joint. The femoropatellar joint was best accessed via a lateral approach, between the middle and lateral patellar ligaments. The axial portion of the medial femorotibial joint was viewed from a medial approach between the middle and medial patellar ligaments and the abaxial portion was viewed from a lateral approach between the middle and the lateral patellar ligaments. The axial portion of the lateral femorotibial joint was viewed from a lateral approach between the middle and the lateral patellar ligaments and the abaxial portion was viewed from a medial approach between the middle and medial patellar ligaments. The results of this study provide guidelines regarding the location of arthroscopic portals to evaluate precisely different areas of the stifle in cattle. PMID:24587506

  5. An examination of ankle, knee, and hip torque production in individuals with chronic ankle instability.

    PubMed

    Gribble, Phillip A; Robinson, Richard H

    2009-03-01

    There is some debate in the literature as to whether strength deficits exist at the ankle in individuals with chronic ankle instability (CAI). Additionally, there is evidence to suggest that knee and hip performance is altered in those with CAI. Therefore, the purpose of this study was to determine whether CAI is associated with deficits in ankle, knee, and hip torque. Fifteen subjects with unilateral CAI and fifteen subjects with healthy ankles participated. Subjects reported to the laboratory for one session during which the torque production of ankle plantar flexion/dorsiflexion, knee flexion/extension, and hip flexion/extension were measured with an isokinetic device. Subjects performed 5 maximum-effort repetitions of a concentric/concentric protocol at 60 degrees .s for both extremities. Average peak torque (APT) values were calculated. The subjects with CAI demonstrated significantly less APT production for knee flexion (F1,28 = 5.40; p = 0.03) and extension (F1,28 = 5.34; p = 0.03). Subjects with CAI exhibited significantly less APT for ankle plantar flexion in the injured limb compared with their noninjured limb (F1,28 = 6.51; p = 0.02). No significant difference in ankle dorsiflexion or hip flexion/extension APT production existed between the 2 groups. Individuals with CAI, in addition to deficits in ankle plantar flexion torque, had deficits in knee flexor and extensor torque, suggesting that distal joint instability may lead to knee joint neuromuscular adaptations. There were no similar deficits at the hip. Future research should determine what implications this has for prevention and rehabilitation of lower-extremity injury. Clinicians may need to consider including rehabilitation efforts to address these deficits when rehabilitating patients with CAI.

  6. Predictive Factors for Lateral Ankle Sprains: A Literature Review

    PubMed Central

    Beynnon, Bruce D.; Murphy, Darlene F.; Alosa, Denise M.

    2002-01-01

    Objective: To review the prospective studies of ankle-ligament-injury risk factors. Data Sources: We searched MEDLINE from 1978 to 2001 using the terms ankle, ligament, injury, risk factor, and epidemiology. Data Synthesis: The results included many studies on the treatment and prevention of ankle injuries. There were, however, very few prospective studies focusing on identifying the risk factors that predispose an athlete to ankle-ligament trauma. Conclusions/Recommendations: There is some agreement among authors with regard to the risk factors for ankle-ligament injury; however, considerable controversy remains. Although female athletes are at significantly greater risk of suffering a serious knee sprain, such as disruption of the anterior cruciate ligament, this does not appear to be the case for ankle-ligament sprains. Therefore, sex does not appear to be a risk factor for suffering an ankle-ligament sprain. Athletes who have suffered a previous sprain have a decreased risk of reinjury if a brace is worn, and the consensus is that generalized joint laxity and anatomical foot type are not risk factors for ankle sprains. However, the literature is divided with regard to whether or not height, weight, limb dominance, ankle-joint laxity, anatomical alignment, muscle strength, muscle-reaction time, and postural sway are risk factors for ankle sprains. Future research is needed on this topic to develop a consensus on all ankle-injury risk factors. This will allow future intervention studies to be designed that will reduce the incidence and severity of this common injury. PMID:12937558

  7. Fibrochondrogenic potential of synoviocytes from osteoarthritic and normal joints cultured as tensioned bioscaffolds for meniscal tissue engineering in dogs.

    PubMed

    Warnock, Jennifer J; Bobe, Gerd; Duesterdieck-Zellmer, Katja F

    2014-01-01

    Meniscal tears are a common cause of stifle lameness in dogs. Use of autologous synoviocytes from the affected stifle is an attractive cell source for tissue engineering replacement fibrocartilage. However, the diseased state of these cells may impede in vitro fibrocartilage formation. Synoviocytes from 12 osteoarthritic ("oaTSB") and 6 normal joints ("nTSB") were cultured as tensioned bioscaffolds and compared for their ability to synthesize fibrocartilage sheets. Gene expression of collagens type I and II were higher and expression of interleukin-6 was lower in oaTSB versus nTSB. Compared with nTSB, oaTSB had more glycosaminoglycan and alpha smooth muscle staining and less collagen I and II staining on histologic analysis, whereas collagen and glycosaminoglycan quantities were similar. In conclusion, osteoarthritic joint-origin synoviocytes can produce extracellular matrix components of meniscal fibrocartilage at similar levels to normal joint-origin synoviocytes, which makes them a potential cell source for canine meniscal tissue engineering. PMID:25289180

  8. Kinematic evaluation of movement smoothness in golf: relationship between the normalized jerk cost of body joints and the clubhead

    PubMed Central

    2014-01-01

    Background When the human body is introduced to a new motion or movement, it learns the placement of different body parts, sequential muscle control, and coordination between muscles to achieve necessary positions, and it hones this new skill over time and repetition. Previous studies have demonstrated definite differences in the smoothness of body movements with different levels of training, i.e., amateurs compared with professionals. Therefore, we tested the hypothesis that skilled golfers swing a driver with a smoother motion than do unskilled golfers. In addition, the relationship between the smoothness of body joints and that of the clubhead was evaluated to provide further insight into the mechanism of smooth golf swing. Methods Two subject groups (skilled and unskilled) participated in the experiment. The skilled group comprised 20 male professional golfers registered with the Korea Professional Golf Association, and the unskilled group comprised 19 amateur golfers who enjoy golf as a hobby. Six infrared cameras (VICON460 system) were used to record the 3D trajectories of markers attached to the clubhead and body segments, and the resulting data was evaluated with kinematic analysis. A physical quantity called jerk was calculated to investigate differences in smoothness during downswing between the two study groups. Results The hypothesis that skilled golfers swing a driver with a smoother motion than do unskilled golfers was supported. The normalized jerk of the clubhead of skilled golfers was lower than that of unskilled golfers in the anterior/posterior, medial/lateral, and proximal/distal directions. Most human joints, especially in the lower body, had statistically significant lower normalized jerk values in the skilled group. In addition, the normalized jerk of the skilled group’s lower body joints had a distinct positive correlation with the normalized jerk of the clubhead with r = 0.657 (p < 0.01). Conclusions The result of this study

  9. Mechanics and energetics of level walking with powered ankle exoskeletons.

    PubMed

    Sawicki, Gregory S; Ferris, Daniel P

    2008-05-01

    Robotic lower limb exoskeletons that can alter joint mechanical power output are novel tools for studying the relationship between the mechanics and energetics of human locomotion. We built pneumatically powered ankle exoskeletons controlled by the user's own soleus electromyography (i.e. proportional myoelectric control) to determine whether mechanical assistance at the ankle joint could reduce the metabolic cost of level, steady-speed human walking. We hypothesized that subjects would reduce their net metabolic power in proportion to the average positive mechanical power delivered by the bilateral ankle exoskeletons. Nine healthy individuals completed three 30 min sessions walking at 1.25 m s(-1) while wearing the exoskeletons. Over the three sessions, subjects' net metabolic energy expenditure during powered walking progressed from +7% to -10% of that during unpowered walking. With practice, subjects significantly reduced soleus muscle activity (by approximately 28% root mean square EMG, P<0.0001) and negative exoskeleton mechanical power (-0.09 W kg(-1) at the beginning of session 1 and -0.03 W kg(-1) at the end of session 3; P=0.005). Ankle joint kinematics returned to similar patterns to those observed during unpowered walking. At the end of the third session, the powered exoskeletons delivered approximately 63% of the average ankle joint positive mechanical power and approximately 22% of the total positive mechanical power generated by all of the joints summed (ankle, knee and hip) during unpowered walking. Decreases in total joint positive mechanical power due to powered ankle assistance ( approximately 22%) were not proportional to reductions in net metabolic power ( approximately 10%). The ;apparent efficiency' of the ankle joint muscle-tendon system during human walking ( approximately 0.61) was much greater than reported values of the ;muscular efficiency' of positive mechanical work for human muscle ( approximately 0.10-0.34). High ankle joint

  10. Ankle-Knee prosthesis with powered ankle and energy transfer for CYBERLEGs α-prototype.

    PubMed

    Geeroms, J; Flynn, L; Jimenez-Fabian, R; Vanderborght, B; Lefeber, D

    2013-06-01

    Restoring natural walking for amputees has been increasingly investigated because of demographic evolution, leading to increased number of amputations, and increasing demand for independence. The energetic disadvantages of passive pros-theses are clear, and active prostheses are limited in autonomy. This paper presents the simulation, design and development of an actuated knee-ankle prosthesis based on a variable stiffness actuator with energy transfer from the knee to the ankle. This approach allows a good approximation of the joint torques and the kinematics of the human gait cycle while maintaining compliant joints and reducing energy consumption during level walking. This first prototype consists of a passive knee and an active ankle, which are energetically coupled to reduce the power consumption.

  11. Joints at high angles to normal fault strike: an explanation using 3-D numerical models of fault-perturbed stress fields

    NASA Astrophysics Data System (ADS)

    Kattenhorn, Simon A.; Aydin, Atilla; Pollard, David D.

    2000-01-01

    Structural methods based on homogeneous stress states predict that joints growing in an extending crust form with strike orientations identical to normal faults. However, we document a field example where the strikes of genetically related normal faults and joints are almost mutually perpendicular. Field relationships allowed us to constrain the fracture sequence and tectonic environment for fault and joint growth. We hypothesize that fault slip can perturb the surrounding stress field in a manner that controls the orientations of induced secondary structures. Numerical models were used to examine the stress field around normal faults, taking into consideration the effects of 3-D fault shape, geometrical arrangement of overlapping faults, and a range of stress states. The calculated perturbed stress fields around model normal faults indicate that it is possible for joints to form at high angles to fault strike. Such joint growth may occur at the lateral tips of an isolated fault, but is most likely in a relay zone between overlapping faults. However, the angle between joints and faults is also influenced by the remote stress state, and is particularly sensitive to the ratio of fault-parallel to fault-perpendicular stress. As this ratio increases, joints can propagate away from faults at increasingly higher angles to fault strike. We conclude that the combined remote stress state and perturbed local stress field associated with overlapping fault geometries resulted in joint growth at high angles to normal fault strike at a field location in Arches National Park, Utah.

  12. Recycling Energy to Restore Impaired Ankle Function during Human Walking

    PubMed Central

    Collins, Steven H.; Kuo, Arthur D.

    2010-01-01

    Background Humans normally dissipate significant energy during walking, largely at the transitions between steps. The ankle then acts to restore energy during push-off, which may be the reason that ankle impairment nearly always leads to poorer walking economy. The replacement of lost energy is necessary for steady gait, in which mechanical energy is constant on average, external dissipation is negligible, and no net work is performed over a stride. However, dissipation and replacement by muscles might not be necessary if energy were instead captured and reused by an assistive device. Methodology/Principal Findings We developed a microprocessor-controlled artificial foot that captures some of the energy that is normally dissipated by the leg and “recycles” it as positive ankle work. In tests on subjects walking with an artificially-impaired ankle, a conventional prosthesis reduced ankle push-off work and increased net metabolic energy expenditure by 23% compared to normal walking. Energy recycling restored ankle push-off to normal and reduced the net metabolic energy penalty to 14%. Conclusions/Significance These results suggest that reduced ankle push-off contributes to the increased metabolic energy expenditure accompanying ankle impairments, and demonstrate that energy recycling can be used to reduce such cost. PMID:20174659

  13. A retrospective analysis evaluating allogeneic cancellous bone sponge for foot and ankle arthrodesis.

    PubMed

    Brigido, Stephen A; Bleazey, Scott T; Protzman, Nicole M; D'Angelantonio, Albert; Schoenhaus, Harold D

    2013-01-01

    The present retrospective case crossover study was conducted to determine the effectiveness and safety data associated with the use of an allogeneic, cancellous bone sponge in an orthopedic foot and ankle population. We reviewed the medical records of 47 subjects (80 joints) who had undergone foot and/or ankle fusion with the cancellous bone sponge. The records were reviewed up to 12 months postoperatively. The joints included in the present study were 12 ankles, 3 ankle syndesmotic fusions (with concurrent total ankle arthroplasty), 17 subtalar joints, 17 talonavicular joints, 9 calcaneocubiod joints, 1 naviculocuneiform joint, 13 first tarsometatarsal joints, 6 lesser tarsometatarsal joints, and 2 first metatarsophalangeal joints. The endpoints of the present study were solid, sustained foot and ankle fusion, as demonstrated radiographically, and the occurrence of unexpected adverse effects related to the graft. The fusion rates were compared with those reported in other studies. The patient-reported outcome variables for the present study included the visual analog pain scale and the American Orthopaedic Foot and Ankle Score. The use of a cancellous sponge showed statistically significant improvements in pain and function and comparable or better fusion rates compared with outcomes reported in other published reports.

  14. The effects of a strategic strength resistance exercise program on the isokinetic muscular function of the ankle

    PubMed Central

    Jeon, Kyoung-Kyu; Kim, Tae-Young; Lee, Sang-Ho

    2015-01-01

    [Purpose] The purpose of this study was to investigate the effects of a strategic strength resistance exercise program on the isokinetic muscular function of the ankle joint. [Subjects] This study included 22 males in their twenties who were diagnosed with functional injury of the ankle joint. [Methods] To strengthen plantar flexion and dorsiflexion of the ankle joint, 8 weeks of weight, resistance band, and plyometric training, and training using props were performed. [Results] A medical examination by interview indicated that pain, swelling, instability, running, and support capacity of the ankle joint significantly improved with the strategic strength resistance exercise program. For the isokinetic peak torque of the ankles, significant differences were observed in right plantar flexion and bilateral dorsiflexion. [Conclusion] The strategic strength resistance exercise program is highly recommended for the functional stability of the ankle joint. Efficient exercise therapy is useful for muscle damage prevention, muscle strengthening, and functional interventions. PMID:26644696

  15. Finite element analysis of a composite artificial ankle

    NASA Technical Reports Server (NTRS)

    Perkins, Leigh Ann; Johnston, Lawrence; Denniston, Charles; Czekalski, Blaise E.

    1993-01-01

    Ultra-light carbon fiber composite materials are being utilized in artificial limbs with increasing frequency in recent years. Dr. Arthur Copes, an orthotist from Baton Rouge, Louisiana, has developed a graphite expoxy composite material artificial ankle (Copes/Bionic Ankle) that is intended to be used by amputees who require the most advanced above-and-below-the-knee prosthetic devices. The Copes/Bionic Ankle is designed to reproduce the function of the natural ankle joint by allowing the composite material to act as a spring mechanism without the use of metal mechanical parts. NASA Marshall Space Flight Center has agreed to participate in the design effort by providing the structural analysis of the artificial ankle design.

  16. Functional Design in Rehabilitation: Modular Mechanisms for Ankle Complex

    PubMed Central

    2016-01-01

    This paper is aimed at presenting an innovative ankle rehabilitation device based on a parallel mechanism. A functional analysis and design are described to obtain a device able to guarantee ankle movement while patient's body remains stationary. Human ankle is a challenging context where a series of joints are highly integrated. The proposed rehabilitation device permits a patient with walking defects to improve his or her gait. The research focuses on plantar-flexion-dorsiflexion movement. The robust design starts from an accurate modelling of ankle movements during walking, assessing motion data from healthy individuals and patients. The kinematics analysis and functional evaluations lead the study and development of the articulated system. In particular, results of simulations support the effectiveness of the current design. A 3D prototype is presented highlighting that the ankle motion is successfully demonstrated. PMID:27524881

  17. Functional Design in Rehabilitation: Modular Mechanisms for Ankle Complex.

    PubMed

    Aggogeri, Francesco; Pellegrini, Nicola; Adamini, Riccardo

    2016-01-01

    This paper is aimed at presenting an innovative ankle rehabilitation device based on a parallel mechanism. A functional analysis and design are described to obtain a device able to guarantee ankle movement while patient's body remains stationary. Human ankle is a challenging context where a series of joints are highly integrated. The proposed rehabilitation device permits a patient with walking defects to improve his or her gait. The research focuses on plantar-flexion-dorsiflexion movement. The robust design starts from an accurate modelling of ankle movements during walking, assessing motion data from healthy individuals and patients. The kinematics analysis and functional evaluations lead the study and development of the articulated system. In particular, results of simulations support the effectiveness of the current design. A 3D prototype is presented highlighting that the ankle motion is successfully demonstrated.

  18. Functional Design in Rehabilitation: Modular Mechanisms for Ankle Complex.

    PubMed

    Aggogeri, Francesco; Pellegrini, Nicola; Adamini, Riccardo

    2016-01-01

    This paper is aimed at presenting an innovative ankle rehabilitation device based on a parallel mechanism. A functional analysis and design are described to obtain a device able to guarantee ankle movement while patient's body remains stationary. Human ankle is a challenging context where a series of joints are highly integrated. The proposed rehabilitation device permits a patient with walking defects to improve his or her gait. The research focuses on plantar-flexion-dorsiflexion movement. The robust design starts from an accurate modelling of ankle movements during walking, assessing motion data from healthy individuals and patients. The kinematics analysis and functional evaluations lead the study and development of the articulated system. In particular, results of simulations support the effectiveness of the current design. A 3D prototype is presented highlighting that the ankle motion is successfully demonstrated. PMID:27524881

  19. The effects of ankle Kinesio taping on ankle stiffness and dynamic balance.

    PubMed

    Fayson, Shirleeah D; Needle, Alan R; Kaminski, Thomas W

    2013-01-01

    The purpose of this study was to determine the effects of Kinesio® taping on static restraint and dynamic postural control of the ankle joint. Thirty female subjects with no history of ankle injury participated in this study. Subjects were tested for passive ankle laxity and stiffness, and time to stabilization following forward, backward, medial, and lateral hops. Subjects were tested prior to tape application, immediately following application, and following 24 hours of use. Differences between taping conditions were investigated using analyses of variance and pairwise comparisons. Stiffness increased following initial application and 24 hours of Kinesio® tape use (F = 6.99, p = .003), despite no observed changes in ankle laxity (F = 0.77, p = .49); however, no changes were observed in time-to-stabilization (F = 0.03, p = .97). Our results suggest that Kinesio® tape may improve static restraint in the ankle joint without altering peak motion or dynamic postural control. A future investigation into Kinesio® tape efficacy in injury prevention or rehabilitation is warranted. PMID:23777376

  20. The effects of ankle Kinesio taping on ankle stiffness and dynamic balance.

    PubMed

    Fayson, Shirleeah D; Needle, Alan R; Kaminski, Thomas W

    2013-01-01

    The purpose of this study was to determine the effects of Kinesio® taping on static restraint and dynamic postural control of the ankle joint. Thirty female subjects with no history of ankle injury participated in this study. Subjects were tested for passive ankle laxity and stiffness, and time to stabilization following forward, backward, medial, and lateral hops. Subjects were tested prior to tape application, immediately following application, and following 24 hours of use. Differences between taping conditions were investigated using analyses of variance and pairwise comparisons. Stiffness increased following initial application and 24 hours of Kinesio® tape use (F = 6.99, p = .003), despite no observed changes in ankle laxity (F = 0.77, p = .49); however, no changes were observed in time-to-stabilization (F = 0.03, p = .97). Our results suggest that Kinesio® tape may improve static restraint in the ankle joint without altering peak motion or dynamic postural control. A future investigation into Kinesio® tape efficacy in injury prevention or rehabilitation is warranted.

  1. Normal and Shear Interactions between Hyaluronan–Aggrecan Complexes Mimicking Possible Boundary Lubricants in Articular Cartilage in Synovial Joints

    PubMed Central

    2012-01-01

    Using a surface force balance, normal and shear interactions have been measured between two atomically smooth surfaces coated with hyaluronan (HA), and with HA/aggrecan (Agg) complexes stabilized by cartilage link protein (LP). Such HA/Agg/LP complexes are the most abundant mobile macromolecular species permeating articular cartilage in synovial joints and have been conjectured to be present as boundary lubricants at its surface. The aim of the present study is to gain insight into the extremely efficient lubrication when two cartilage surfaces slide past each other in healthy joints, and in particular to elucidate the possible role in this of the HA/Agg/LP complexes. Within the range of our parameters, our results reveal that the HA/Agg/LP macromolecular surface complexes are much better boundary lubricants than HA alone, likely because of the higher level of hydration, due to the higher charge density, of the HA/Agg/LP layers with respect to the HA alone. However, the friction coefficients (μ) associated with the mutual interactions and sliding of opposing HA/Agg/LP layers (μ ≈ 0.01 up to pressure P of ca. 12 atm, increasing sharply at higher P) suggest that such complexes by themselves cannot account for the remarkable boundary lubrication observed in mammalian joints (up to P > 50 atm). PMID:23074968

  2. Forces predicted at the ankle during running.

    PubMed

    Burdett, R G

    1982-01-01

    A biomechanical model of the ankle joint was developed and was used to predict the forces at the ankle during the stance phase of running. Measurements from five cadavers were averaged to obtain insertion points and directions of pull of equivalent tendons with respect to the assumed center of the ankle joint. A minimum joint force solution was obtained by assuming that only two equivalent muscle groups could exert force at one time. Three subjects ran at 4.47 m/s across a force platform that recorded the external forces and moments acting on the foot. Cinematography was used to measure the foot and leg positions during stance. Peak resultant joint forces ranging from 9.0 to 13.3 times body weight and peak Achilles tendon forces ranging from 5.3 to 10.0 times body weight were predicted. Small variations in some cases resulted in large differences in predicted forces. The highest tendon forces predicted exceeded those reported to cause damage to cadaver tendons in other studies. PMID:7132650

  3. Development of restraint material and tucked fabric joints

    NASA Technical Reports Server (NTRS)

    Mcmullen, J. M.

    1975-01-01

    A study was conducted to evaluate and select a suitable restraint material for the exterior of space suits pressurized to 4.0 PSID for normal operations, and to develop and improve tucked fabric joints for motions associated with the human shoulder, elbow, knee, waist, hip, ankle, and wrist. The many attributes of the end items are summarized to include structural integrity, simplicity, low maintenance, lightweight, high durability, low elongation, full range mobility, long life, and resistance to degradation in the operational environment.

  4. Ultrasound-guided interventions of the foot and ankle.

    PubMed

    Yablon, Corrie M

    2013-02-01

    Ultrasound (US) provides excellent delineation of tendons and ligaments in the foot and ankle and provides real-time visualization of a needle during interventions, yielding greater accuracy and efficacy than the traditional blind approach using anatomical landmarks. For this reason, US is rapidly gaining acceptance as the preferred modality for guiding interventions in the foot and ankle where the anatomy is complex, neurovascular structures should be identified, and precise technique is demanded. In the foot and ankle, US is especially useful to guide tendon sheath, bursal, and Achilles paratenon injections, Morton neuroma injections, plantar fascial injections, and joint aspirations and injections.

  5. Independent ankle motion control improves robotic balance simulator.

    PubMed

    Pospisil, Eric R; Luu, Billy L; Blouin, Jean-Sébastien; Van der Loos, H F Machiel; Croft, Elizabeth A

    2012-01-01

    We present a validation study for the effectiveness of an additional ankle-tilt platform to enhance somatosensory ankle feedback available to subjects actuating a 6-axis robotic balance simulator platform. To address this need, we have developed and integrated a device to permit independent manipulation of ankle rotation while the whole-body is actuated by the balance simulator. The addition of ankle rotation is shown to provide both quantitative and qualitative improvements to the balance simulation experience compared to when the ankle joint is referenced to the motion of the balance simulator. Eight out of ten subjects reported that balancing on the simulator with ankle motion required less conscious effort. This self-reported improvement corresponded to a 32% decrease in the mean-removed RMS amplitude for sway angle, demonstrating better balance control for subjects actuating the simulator. The new ankle-tilt platform enables examination of the contributions of ankle proprioception to the control of standing balance in human subjects.

  6. Review on design and control aspects of ankle rehabilitation robots.

    PubMed

    Jamwal, Prashant K; Hussain, Shahid; Xie, Sheng Q

    2015-03-01

    Ankle rehabilitation robots can play an important role in improving outcomes of the rehabilitation treatment by assisting therapists and patients in number of ways. Consequently, few robot designs have been proposed by researchers which fall under either of the two categories, namely, wearable robots or platform-based robots. This paper presents a review of both kinds of ankle robots along with a brief analysis of their design, actuation and control approaches. While reviewing these designs it was observed that most of them are undesirably inspired by industrial robot designs. Taking note of the design concerns of current ankle robots, few improvements in the ankle robot designs have also been suggested. Conventional position control or force control approaches, being used in the existing ankle robots, have been reviewed. Apparently, opportunities of improvement also exist in the actuation as well as control of ankle robots. Subsequently, a discussion on most recent research in the development of novel actuators and advanced controllers based on appropriate physical and cognitive human-robot interaction has also been included in this review. Implications for Rehabilitation Ankle joint functions are restricted/impaired as a consequence of stroke or injury during sports or otherwise. Robots can help in reinstating functions faster and can also work as tool for recording rehabilitation data useful for further analysis. Evolution of ankle robots with respect to their design and control aspects has been discussed in the present paper and a novel design with futuristic control approach has been proposed. PMID:24320195

  7. Review on design and control aspects of ankle rehabilitation robots.

    PubMed

    Jamwal, Prashant K; Hussain, Shahid; Xie, Sheng Q

    2015-03-01

    Ankle rehabilitation robots can play an important role in improving outcomes of the rehabilitation treatment by assisting therapists and patients in number of ways. Consequently, few robot designs have been proposed by researchers which fall under either of the two categories, namely, wearable robots or platform-based robots. This paper presents a review of both kinds of ankle robots along with a brief analysis of their design, actuation and control approaches. While reviewing these designs it was observed that most of them are undesirably inspired by industrial robot designs. Taking note of the design concerns of current ankle robots, few improvements in the ankle robot designs have also been suggested. Conventional position control or force control approaches, being used in the existing ankle robots, have been reviewed. Apparently, opportunities of improvement also exist in the actuation as well as control of ankle robots. Subsequently, a discussion on most recent research in the development of novel actuators and advanced controllers based on appropriate physical and cognitive human-robot interaction has also been included in this review. Implications for Rehabilitation Ankle joint functions are restricted/impaired as a consequence of stroke or injury during sports or otherwise. Robots can help in reinstating functions faster and can also work as tool for recording rehabilitation data useful for further analysis. Evolution of ankle robots with respect to their design and control aspects has been discussed in the present paper and a novel design with futuristic control approach has been proposed.

  8. Effects of repeated ankle stretching on calf muscle-tendon and ankle biomechanical properties in stroke survivors

    PubMed Central

    Gao, Fan; Ren, Yupeng; Roth, Elliot J.; Harvey, Richard; Zhang, Li-Qun

    2011-01-01

    Background The objective of this study was to investigate changes in active and passive biomechanical properties of the calf muscle-tendon unit induced by controlled ankle stretching in stroke survivors. Methods Ten stroke survivors with ankle spasticity/contracture and ten healthy control subjects received intervention of 60-min ankle stretching. Joint biomechanical properties including resistance torque, stiffness and index of hysteresis were evaluated pre- and post-intervention. Achilles tendon length was measured using ultrasonography. The force output of the triceps surae muscles was characterized via the torque-angle relationship, by stimulating the calf muscles at a controlled intensity across different ankle positions. Findings Compared to healthy controls, the ankle position corresponding to the peak torque of the stroke survivors was shifted towards plantar flexion (P<0.001). Stroke survivors showed significantly higher resistance torques and joint stiffness (P<0.05), and these higher resistances were reduced significantly after the stretching intervention, especially in dorsiflexion (P = 0.013). Stretching significantly improved the force output of the impaired calf muscles in stroke survivors under matched stimulations (P<0.05). Ankle range of motion was also increased by stretching (P<0.001). Interpretation At the joint level, repeated stretching loosened the ankle joint with increased passive joint range of motion and decreased joint stiffness. At the muscle-tendon level, repeated stretching improved calf muscle force output, which might be associated with decreased muscle fascicle stiffness, increased fascicle length and shortening of the Achilles tendon. The study provided evidence of improvement in muscle tendon properties through stretching intervention. PMID:21211873

  9. Effects of hip and head position on ankle range of motion, ankle passive torque, and passive gastrocnemius tension.

    PubMed

    Andrade, R J; Lacourpaille, L; Freitas, S R; McNair, P J; Nordez, A

    2016-01-01

    Ankle joint range of motion (ROM) is notably influenced by the position of the hip joint. However, this result remains unexplained. Thus, the aim of this study was to test if the ankle passive torque and gastrocnemius muscle tension are affected by the hip and the head positions. The torque and the muscle shear elastic modulus (measured by elastography to estimate muscle tension) were collected in nine participants during passive ankle dorsiflexions performed in four conditions (by combining hip flexion at 90 or 150°, and head flexed or neutral). Ankle maximum dorsiflexion angle significantly decreased by flexing the hip from 150 to 90° (P < 0.001; mean difference 17.7 ± 2.5°), but no effect of the head position was observed (P > 0.05). Maximal passive torque and shear elastic modulus were higher with the hip flexed at 90° (P < 0.001). During submaximal ROM, no effects of the head and hip positioning (P > 0.05) were found for both torque and shear elastic modulus at a given common ankle angle among conditions. Shifts in maximal ankle angle due to hip angle manipulation are not related neither to changes in passive torque nor tension of the gastrocnemius. Further studies should be addressed to better understand the functional role of peripheral nerves and fasciae in the ankle ROM limits.

  10. Prevention of ankle sprains.

    PubMed

    Walsh, W M; Blackburn, T

    1977-01-01

    Ankles are sprained when supported on an unstable foundation, while too rididly fixed to the playing surface, or when forced into unnatural positions by extrinsic muscle tightness. The unstable foundation may be the shoe itself, a chuck-hole, or another player's foot. Undue fixation may be by 1-inch mud cleats, baseball spikes, or a modern wrestling mat. When these circumstances occur, heel cord tightness may alter the ankle's response. Thus, prevention of ankle sprains may be by modification of any of these factors.

  11. Gait changes after using a temporomandibular joint exerciser in patients who underwent lower limb joint surgery

    PubMed Central

    Chung, Gu-Young; Choi, Geun-Seok; Shin, Ki-Young; Park, Joon-Soo

    2016-01-01

    [Purpose] The improvements in gait of the patients with lower limb disease who used a temporomandibular joint (TMJ) exerciser were verified. [Subjects and Methods] Eleven subjects were included. Their mean age was 53.2 years. The lower limb joint angles before and after using the TMJ exerciser were measured using a gait analyzer. Before the gait experiment, the TMJ exerciser setting process and one-leg stance balance test (OLST) were repeated until the balance maintenance time improved. [Results] Because of the OLST, the mean change in the body center point after the subjects used the exerciser improved from 5.76 mm to 4.20 mm. When the TMJ exerciser was used, the joint angle range of the subjects approached that of the normal individuals. [Conclusion] According to the gait experiments, the angles of the subjects’ hips, knees, and ankle joints approached to those of the normal individuals after the subjects used the TMJ exerciser; however, the results did not completely match. The changes in the hip, knee, and ankle joint angles were statistically significant, which confirm the usefulness of the TMJ exerciser. PMID:27313377

  12. Assessment of AK (Above Knee) Prosthesis with Different Ankle Assembly Using GRF Pattern in Stance Phase

    NASA Astrophysics Data System (ADS)

    Kim, Sung-Min; Kim, Sung-Jae; Bae, Ha-Suk

    In this study, ground reaction force (GRF), absolute symmetry index (ASI) and coefficient of variation (CV) of fixed, single-axis and multi-axis prosthetic ankle assemblies were investigated by biomechanical evaluation of above knee amputees. In the experiments, 37 normal male volunteers, two male and two female Above Knee (AK) amputees GRF data were tested with fixed, single-axis and multi-axis prosthetic ankle assembly. A gait analysis was carried out to derive the ratio of GRF to weight as the percentage of total stance phase for ten points. The results showed that fixed-axis ankle assembly was superior to other two ankle assemblies for forwarding and braking forces. Multi-axis ankle was relatively superior to other two ankle assemblies for gait balancing and movement of the mass center. Single-axis ankle was relatively superior to the other two ankle assemblies for CV and ASI of GRF.

  13. Imaging in Foot and Ankle Arthritis.

    PubMed

    Wilkinson, Victoria H; Rowbotham, Emma L; Grainger, Andrew J

    2016-04-01

    The foot and ankle are commonly involved in a range of arthritides that affect the joints, bones, and soft tissues. Accurate plain film interpretation can often aid the diagnosis and monitor disease progression and treatment response. Ultrasound and MRI afford superior depiction of the soft tissues, and advances over recent years have centered on early detection of synovitis, enabling earlier diagnosis and treatment. Advantages and disadvantages of the imaging techniques of radiography, multidetector computed tomography, ultrasound, and MRI are discussed, as is optimization of these modalities for the assessment of the anatomically complex joints of the foot and ankle. Diagnostic features enabling differentiation between rheumatoid arthritis, seronegative spondyloarthropathies, osteoarthritis, gout, crystal deposition disease, pigmented villonodular synovitis, Charcot arthropathy, septic arthritis, synovial osteochondromatosis, hemophilia, and reflex sympathetic dystrophy are also reviewed. PMID:27336451

  14. Prediction of medial and lateral contact force of the knee joint during normal and turning gait after total knee replacement.

    PubMed

    Purevsuren, Tserenchimed; Dorj, Ariunzaya; Kim, Kyungsoo; Kim, Yoon Hyuk

    2016-04-01

    The computational modeling approach has commonly been used to predict knee joint contact forces, muscle forces, and ligament loads during activities of daily living. Knowledge of these forces has several potential applications, for example, within design of equipment to protect the knee joint from injury and to plan adequate rehabilitation protocols, although clinical applications of computational models are still evolving and one of the limiting factors is model validation. The objective of this study was to extend previous modeling technique and to improve the validity of the model prediction using publicly available data set of the fifth "Grand Challenge Competition to Predict In Vivo Knee Loads." A two-stage modeling approach, which combines conventional inverse dynamic analysis (the first stage) with a multi-body subject-specific lower limb model (the second stage), was used to calculate medial and lateral compartment contact forces. The validation was performed by direct comparison of model predictions and experimental measurement of medial and lateral compartment contact forces during normal and turning gait. The model predictions of both medial and lateral contact forces showed strong correlations with experimental measurements in normal gait (r = 0.75 and 0.71) and in turning gait trials (r = 0.86 and 0.72), even though the current technique over-estimated medial compartment contact forces in swing phase. The correlation coefficient, Sprague and Geers metrics, and root mean squared error indicated that the lateral contact forces were predicted better than medial contact forces in comparison with the experimental measurements during both normal and turning gait trials. PMID:26908641

  15. Presence of neuroreceptors in normal and diseased temporo-mandibular joints.

    PubMed

    Favia, G; Maiorano, E

    1995-01-01

    An immunohistochemical study was performed on the articular disk and periarticular tissues of the temporo-mandibular joint (TMJ) in order to ascertain the presence of neuroreceptors (NRec) in these sites. The study was carried out with the APAAP technique on tissue samples obtained from 10 subjects without known TMJ disease and from 5 patients with severe TMJ arthritis or arthrosis. The antibodies used were directed against the following antigens: Gliofibrillary Acidic Protein (GFAP), Leu-7, Myelin Basic Protein (MBP), Neurofilaments 68 kD (NF), Neuron Specific Enolase (NSE), S-100 protein (S-100) and Synaptophysin (SYN). This study revealed that Ruffini's-like, Pacini's-like and Golgi's-like receptors can be demonstrated in TMJ periarticular tissues and that free nervous endings are present in the subsynovial but not within the articular disk. In the latter, elongated cytoplasmic processes of chondrocytes demonstrated strong S-100 immunoreactivity but they were unreactive with all other antibodies. These cytoplasmic processes were more abundant and thicker in the samples obtained from patients with diseased TMJ. The results of this study confirm that different NRec are detectable in TMJ periarticular tissues but they are absent within the articular disk. In the latter site, only chondrocytic processes are evident, especially in diseased TMJ, and they might have been confused with nervous endings in previous morphological studies. Nevertheless the absence of immunoreactivity for NF, NSE and SYN proves that they are not of neural origin.

  16. Design of a quasi-passive 3 DOFs ankle-foot wearable rehabilitation orthosis.

    PubMed

    Zhang, Chao; Zhu, Yanhe; Fan, Jizhuang; Zhao, Jie; Yu, Hongying

    2015-01-01

    Muscular rigidity and atrophy caused by long-term underactivity usually lead to foot drop, strephenopodia, foot extorsion or some other complications for the lower limb movement disorders or lower limb surgery sufferers. The ankle-foot orthosis can help patients conduct the right ankle motion mode training, inhibit spasm and prevent ankle complications. In this paper, a quasi-passive 3 DOFs ankle-foot wearable orthosis was designed on the basis of kinematics and dynamics analysis of the ankle joint. Ankle joint trajectory and dynamic characteristics similar to those of natural gait can be obtained by the combination of passive energy storage and additional power complement. In terms of function, the orthosis has shock absorption and low energy consumption. Given its excellent characteristics of comfortableness, lightweight, and anthropomorphic construction, the orthosis can be used in medical institutions for rehabilitation training or as a daily-walking auxiliary equipment for surgery sufferers.

  17. Imaging of the foot and ankle.

    PubMed

    Pavlov, H

    1990-09-01

    The foot and ankle are subjected to daily stresses and strains ranging from normal walking activities to the excessive forces encountered in the active sports enthusiast. These traumatic events as well as systemic and local arthritic conditions and tumors can be temporarily or permanently disabling. Early, expedited, and cost-efficient diagnosis is the daily challenge for the radiologist, clinician, and patient. PMID:1975109

  18. Pediatric Ankle Fractures: Concepts and Treatment Principles.

    PubMed

    Su, Alvin W; Larson, A Noelle

    2015-12-01

    Current clinical concepts are reviewed regarding the epidemiology, anatomy, evaluation, and treatment of pediatric ankle fractures. Correct diagnosis and management relies on appropriate examination, imaging, and knowledge of fracture patterns specific to children. Treatment is guided by patient history, physical examination, plain film radiographs and, in some instances, computed tomography. Treatment goals are to restore acceptable limb alignment, physeal anatomy, and joint congruency. For high-risk physeal fractures, patients should be monitored for growth disturbance as needed until skeletal maturity. PMID:26589088

  19. Assessment of dorsal instability of the ulnar head in the distal radioulnar joint: comparison between normal wrist joints and cases of ruptured extensor tendons.

    PubMed

    Naito, Kiyohito; Sugiyama, Yoichi; Aritomi, Kentaro; Nagahama, Yasushi; Tomita, Yoshimasa; Obayashi, Osamu; Kaneko, Kazuo

    2016-02-01

    In the present study, the adaptability of the distal radioulnar joint (DRUJ) was evaluated using conventional computed tomography (CT) evaluation methods. In addition, we investigated/compared a new method to evaluate dorsal displacement of the ulnar head. Our subjects consisted of 32 healthy volunteers (64 wrists) and 11 patients (13 wrists) with extensor tendon injuries related to dorsal displacement of the ulnar head. To diagnose instability in the DRUJ based on CT scans, the radioulnar line method and the modified radioulnar line method were measured. Instability was evaluated by the new method that the ulnar head was located on the dorsal side from a line involving the peak of Lister's tubercle in parallel to this baseline was regarded as showing abnormal dorsal displacement of the ulnar head. The diagnostic accuracy of each method was calculated. The sensitivities, specificities, false-positive rates, positive predictive values and the negative predictive value of new methods were better than other two methods. The new method that we recommend is simple. Based on the results of this study, an evaluation of normal/abnormal dorsal displacement of the ulnar head in the DRUJ using the new method may be useful for determining the timing of surgery.

  20. Benign joint hypermobility syndrome in soldiers; what is the effect of military training courses on associated joint instabilities?

    PubMed Central

    Azma, Kamran; Mottaghi, Peyman; Hosseini, Alireza; Abadi, Hossein Hassan; Nouraei, Mohammad Hadi

    2014-01-01

    Background: Hypermobile joints are joints with beyond normal range of motion and may be associated with joint derangements. This study aimed to evaluate the prevalence of benign joint hypermobility syndrome (BJHS) among soldiers and effect of training courses on related joint instabilities. Materials and Methods: In a prospective cohort study on 721 soldiers of Iran Army in Isfahan in 2013 the prevalence of joint hypermobility was obtained by using Beighton criteria. Soldiers divided in two groups of healthy and suffered based on their scores. The prevalence of ankle sprain, shoulder and temporomandibular joint (TMJ) dislocations identified before beginning service by history-taking and reviewing paraclinical documents. After 3 months of military training, a recent occurrence of mentioned diseases was revaluated in two groups. The collected data were analyzed using SPSS-20 software using Independent-T and Chi-square tests. Results: The frequency of BJHS before military training was 29.4%. After passing military training period, the incidence of ankle sprain was significantly higher in suffered group achieving the minimum Beighton score (BS) of 4 (4.3%, P = 0.03), 5 (5.5%, P = 0.005) and also 6 out of 9 (6.5%, P = 0.01). The incidence of TMJ dislocation was not significantly different based on a minimum score of 4, while it was higher in suffered group when considering the score of 5 (2.1%) and 6 (2.6%) for discrimination of two groups (P = 0.03). There was no significant difference between two groups in case of shoulder dislocation anyway. Conclusion: Military training can increase the incidence of ankle sprains and TMJ dislocations in hypermobility persons with higher BS in comparison with healthy people. Therefore, screening of joint hypermobility may be useful in identifying individuals at increased risk for joint instabilities. PMID:25364364

  1. Development of a Robotic Assembly for Analyzing the Instantaneous Axis of Rotation of the Foot Ankle Complex.

    PubMed

    Salb, Kelly N; Wido, Daniel M; Stewart, Thomas E; DiAngelo, Denis J

    2016-01-01

    Ankle instantaneous axis of rotation (IAR) measurements represent a more complete parameter for characterizing joint motion. However, few studies have implemented this measurement to study normal, injured, or pathological foot ankle biomechanics. A novel testing protocol was developed to simulate aspects of in vivo foot ankle mechanics during mid-stance gait in a human cadaveric specimen. A lower leg was mounted in a robotic testing platform with the tibia upright and foot flat on the baseplate. Axial tibia loads (ATLs) were controlled as a function of a vertical ground reaction force (vGRF) set at half body weight (356 N) and a 50% vGRF (178 N) Achilles tendon load. Two specimens were repetitively loaded over 10 degrees of dorsiflexion and 20 degrees of plantar flexion. Platform axes were controlled within 2 microns and 0.008 degrees resulting in ATL measurements within ±2 N of target conditions. Mean ATLs and IAR values were not significantly different between cycles of motion, but IAR values were significantly different between dorsiflexion and plantar flexion. A linear regression analysis showed no significant differences between slopes of plantar flexion paths. The customized robotic platform and advanced testing protocol produced repeatable and accurate measurements of the IAR, useful for assessing foot ankle biomechanics under different loading scenarios and foot conditions.

  2. Development of a Robotic Assembly for Analyzing the Instantaneous Axis of Rotation of the Foot Ankle Complex

    PubMed Central

    Salb, Kelly N.; Wido, Daniel M.; Stewart, Thomas E.; DiAngelo, Denis J.

    2016-01-01

    Ankle instantaneous axis of rotation (IAR) measurements represent a more complete parameter for characterizing joint motion. However, few studies have implemented this measurement to study normal, injured, or pathological foot ankle biomechanics. A novel testing protocol was developed to simulate aspects of in vivo foot ankle mechanics during mid-stance gait in a human cadaveric specimen. A lower leg was mounted in a robotic testing platform with the tibia upright and foot flat on the baseplate. Axial tibia loads (ATLs) were controlled as a function of a vertical ground reaction force (vGRF) set at half body weight (356 N) and a 50% vGRF (178 N) Achilles tendon load. Two specimens were repetitively loaded over 10 degrees of dorsiflexion and 20 degrees of plantar flexion. Platform axes were controlled within 2 microns and 0.008 degrees resulting in ATL measurements within ±2 N of target conditions. Mean ATLs and IAR values were not significantly different between cycles of motion, but IAR values were significantly different between dorsiflexion and plantar flexion. A linear regression analysis showed no significant differences between slopes of plantar flexion paths. The customized robotic platform and advanced testing protocol produced repeatable and accurate measurements of the IAR, useful for assessing foot ankle biomechanics under different loading scenarios and foot conditions. PMID:27099456

  3. Ankle dorsi- and plantar-flexion torques measured by dynamometry in healthy subjects from 5 to 80 years

    PubMed Central

    2013-01-01

    Background Ankle strength is often impaired in some of the most common neuromuscular disorders. Consequently, strength generated around this joint is important to assess, because it has a great impact on balance and gait. The objectives of this study were to establish normative data and predictive equations for both ankle dorsi- and plantar-flexion strength from a population of healthy subjects (children and adults), to assess the reliability of the measurements and to study the feasibility of using a novel dynamometer on a group of patients with a neuromuscular disorder. Methods Measurements of maximal isometric torque for dorsi- and plantar-flexion were performed on 345 healthy subjects from 5 to 80 years of age. The feasibility of the method was tested on nine patients diagnosed with type 2A limb girdle muscular dystrophy. Results The results documented normal strength values depending on gender and age on ankle dorsi- and plantar-flexion. The reliability of the technique was good with no evaluator effect and a small learning effect. The dynamometer was found suitable in the group of patients, even very weak. Conclusions The device developed was both reliable and accurate in assessing both ankle dorsi-flexion and plantar-flexion torque measurements from weak patients and children to strong healthy adults. Norms and predictive equations are provided for these two muscle functions. PMID:23522186

  4. Normal and abnormal mechanics of the glenohumeral joint in the horizontal plane.

    PubMed

    Howell, S M; Galinat, B J; Renzi, A J; Marone, P J

    1988-02-01

    This study was performed to evaluate the relationship of the humeral head to the scapula in the horizontal plane of motion and to describe in detail a method of obtaining and interpreting modified axillary roentgenograms. Twenty normal subjects and twelve patients who had anterior instability of the shoulder were evaluated with this technique. In the control group, the humeral head was centered in the glenoid cavity throughout the horizontal plane of motion except when the arm was in maximum extension and external rotation. In this position, the cocked stage of the throwing motion, the center of the humeral head rested approximately four millimeters posterior to the center of the glenoid cavity. When the arm was flexed or rotated from this cocked position, the humeral head glided anteriorly, producing a shearing stress on the articular surface of the glenoid and labrum. In seven of the twelve patients who had anterior instability, abnormal mechanics were observed: anterior translation of the humeral head occurred. This indicates a significant disruption of the structures responsible for containing the humeral head within the glenoid fossa. PMID:3343267

  5. Sonographic anatomy of the ankle.

    PubMed

    Precerutti, M; Bonardi, M; Ferrozzi, G; Draghi, F

    2014-06-01

    Ankle sonography is one of the most commonly ordered examinations in the field of osteoarticular imaging, and it requires intimate knowledge of the anatomic structures that make up the joint. For practical purposes, the examination can be divided into four compartments, which are analyzed in this pictorial essay: the anterior compartment, which includes the tibialis anterior, extensor hallucis longus, and extensor digitorum longus tendons; the accessory peroneus tertius tendon; and the extensor retinaculum; the medial compartment (tibialis posterior, flexor digitorum longus, and flexor hallucis longus tendons; the flexor retinaculum; the medial collateral-or deltoid-ligament, and the neurovascular bundle); the lateral compartment (peroneus longus, peroneus brevis, and peroneus quartus tendons; superior and inferior peroneal retinacula, lateral collateral ligament); and the posterior compartment (Achilles tendon, plantaris tendon, Kagar's triangle, superficial, and deep retrocalcaneal bursae). Scanning techniques are briefly described to ensure optimal visualization of the various anatomic structures.

  6. Sonographic anatomy of the ankle.

    PubMed

    Precerutti, M; Bonardi, M; Ferrozzi, G; Draghi, F

    2014-06-01

    Ankle sonography is one of the most commonly ordered examinations in the field of osteoarticular imaging, and it requires intimate knowledge of the anatomic structures that make up the joint. For practical purposes, the examination can be divided into four compartments, which are analyzed in this pictorial essay: the anterior compartment, which includes the tibialis anterior, extensor hallucis longus, and extensor digitorum longus tendons; the accessory peroneus tertius tendon; and the extensor retinaculum; the medial compartment (tibialis posterior, flexor digitorum longus, and flexor hallucis longus tendons; the flexor retinaculum; the medial collateral-or deltoid-ligament, and the neurovascular bundle); the lateral compartment (peroneus longus, peroneus brevis, and peroneus quartus tendons; superior and inferior peroneal retinacula, lateral collateral ligament); and the posterior compartment (Achilles tendon, plantaris tendon, Kagar's triangle, superficial, and deep retrocalcaneal bursae). Scanning techniques are briefly described to ensure optimal visualization of the various anatomic structures. PMID:24883130

  7. Lateral and syndesmotic ankle sprain injuries: a narrative literature review

    PubMed Central

    Dubin, Joshua C.; Comeau, Doug; McClelland, Rebecca I.; Dubin, Rachel A.; Ferrel, Ernest

    2011-01-01

    Objective The purpose of this article is to review the literature that discusses normal anatomy and biomechanics of the foot and ankle, mechanisms that may result in a lateral ankle sprain or syndesmotic sprain, and assessment and diagnostic procedures, and to present a treatment algorithm based on normal ligament healing principles. Methods Literature was searched for years 2000 to 2010 in PubMed and CINAHL. Key search terms were ankle sprain$, ankle injury and ankle injuries, inversion injury, proprioception, rehabilitation, physical therapy, anterior talofibular ligament, syndesmosis, syndesmotic injury, and ligament healing. Discussion Most ankle sprains respond favorably to nonsurgical treatment, such as those offered by physical therapists, doctors of chiropractic, and rehabilitation specialists. A comprehensive history and examination aid in diagnosing the severity and type of ankle sprain. Based on the diagnosis and an understanding of ligament healing properties, a progressive treatment regimen can be developed. During the acute inflammatory phase, the goal of care is to reduce inflammation and pain and to protect the ligament from further injury. During the reparative and remodeling phase, the goal is to progress the rehabilitation appropriately to facilitate healing and restore the mechanical strength and proprioception. Radiographic imaging techniques may need to be used to rule out fractures, complete ligament tears, or instability of the ankle mortise. A period of immobilization and ambulating with crutches in a nonweightbearing gait may be necessary to allow for proper ligament healing before commencing a more active treatment approach. Surgery should be considered in the case of grade 3 syndesmotic sprain injuries or those ankle sprains that are recalcitrant to conservative care. Conclusion An accurate diagnosis and prompt treatment can minimize an athlete's time lost from sport and prevent future reinjury. Most ankle sprains can be successfully

  8. Joint Instability and Osteoarthritis

    PubMed Central

    Blalock, Darryl; Miller, Andrew; Tilley, Michael; Wang, Jinxi

    2015-01-01

    Joint instability creates a clinical and economic burden in the health care system. Injuries and disorders that directly damage the joint structure or lead to joint instability are highly associated with osteoarthritis (OA). Thus, understanding the physiology of joint stability and the mechanisms of joint instability-induced OA is of clinical significance. The first section of this review discusses the structure and function of major joint tissues, including periarticular muscles, which play a significant role in joint stability. Because the knee, ankle, and shoulder joints demonstrate a high incidence of ligament injury and joint instability, the second section summarizes the mechanisms of ligament injury-associated joint instability of these joints. The final section highlights the recent advances in the understanding of the mechanical and biological mechanisms of joint instability-induced OA. These advances may lead to new opportunities for clinical intervention in the prevention and early treatment of OA. PMID:25741184

  9. Multivariable Dynamic Ankle Mechanical Impedance With Active Muscles

    PubMed Central

    Lee, Hyunglae; Krebs, Hermano Igo; Hogan, Neville

    2015-01-01

    Multivariable dynamic ankle mechanical impedance in two coupled degrees-of-freedom (DOFs) was quantified when muscles were active. Measurements were performed at five different target activation levels of tibialis anterior and soleus, from 10% to 30% of maximum voluntary contraction (MVC) with increments of 5% MVC. Interestingly, several ankle behaviors characterized in our previous study of the relaxed ankle were observed with muscles active: ankle mechanical impedance in joint coordinates showed responses largely consistent with a second-order system consisting of inertia, viscosity, and stiffness; stiffness was greater in the sagittal plane than in the frontal plane at all activation conditions for all subjects; and the coupling between dorsiflexion–plantarflexion and inversion–eversion was small—the two DOF measurements were well explained by a strictly diagonal impedance matrix. In general, ankle stiffness increased linearly with muscle activation in all directions in the 2-D space formed by the sagittal and frontal planes, but more in the sagittal than in the frontal plane, resulting in an accentuated “peanut shape.” This characterization of young healthy subjects’ ankle mechanical impedance with active muscles will serve as a baseline to investigate pathophysiological ankle behaviors of biomechanically and/or neurologically impaired patients. PMID:25203497

  10. Which X-ray views are required in juvenile ankle trauma?

    PubMed

    Heim, M; Blankstein, A; Israeli, A; Horoszowski, H

    1990-01-01

    Although ankle sprains are probably the most common injury in adolescent sports people, epiphyseal injuries are missed on the presumption of a ligamentous tear. The risk of damaged ligaments has been overemphasized while the potentially dangerous epiphyseolysis has been understressed. An oblique X-ray of the ankle joint is indicated prior to "stress" pictures.

  11. Distribution of blood flow in normal and arthritic joints. Role of arteriovenous shunting studied in growing dogs.

    PubMed

    Stender Hansen, E; He, S Z; Hjortdal, V E; Kjølseth, D; Søballe, K

    1992-01-01

    Juvenile dog knee with chronic carrageenin-induced arthritis was studied under general anesthesia with 15-microns and 50-microns-sized microspheres (MS) to compare the distribution of absolute and weight-standardized blood flow in normal and arthritic limbs and to localize possible sites of arteriovenous (AV) shunting. Arthritic joints had severe synovial and capsular hyperemia. Absolute as well as standardized blood flow was increased in juxta-articular epiphyses and patella. Shafts were atrophic and had decreased absolute flow but normal standardized flow. However, redistribution of blood flow occurred among regions within the shafts, e.g., in metaphyses away from growth plates. The mean nonentrapment of 15-microns MS was 13.8% in arthritic limbs and 4.2% in control limbs. The uptake of 50-microns MS was lower than that of 15-microns MS in all bony flow compartments due to differences in their rheologic behavior in larger arteries. The relative distribution of 50-microns MS and 15-microns MS varied considerably among regions within bone. Arthritis caused a net shift in the uptake of 50-microns MS relative to that of 15-microns MS from central to subchondral epiphyseal bone, evidencing precapillary vasodilation, but the relationship was strictly unchanged when bones were examined in toto. This result militates against the hypothesis of AV shunting in arthritic bone. PMID:1733320

  12. Fibrochondrogenic potential of synoviocytes from osteoarthritic and normal joints cultured as tensioned bioscaffolds for meniscal tissue engineering in dogs

    PubMed Central

    Bobe, Gerd; Duesterdieck-Zellmer, Katja F.

    2014-01-01

    Meniscal tears are a common cause of stifle lameness in dogs. Use of autologous synoviocytes from the affected stifle is an attractive cell source for tissue engineering replacement fibrocartilage. However, the diseased state of these cells may impede in vitro fibrocartilage formation. Synoviocytes from 12 osteoarthritic (“oaTSB”) and 6 normal joints (“nTSB”) were cultured as tensioned bioscaffolds and compared for their ability to synthesize fibrocartilage sheets. Gene expression of collagens type I and II were higher and expression of interleukin-6 was lower in oaTSB versus nTSB. Compared with nTSB, oaTSB had more glycosaminoglycan and alpha smooth muscle staining and less collagen I and II staining on histologic analysis, whereas collagen and glycosaminoglycan quantities were similar. In conclusion, osteoarthritic joint—origin synoviocytes can produce extracellular matrix components of meniscal fibrocartilage at similar levels to normal joint—origin synoviocytes, which makes them a potential cell source for canine meniscal tissue engineering. PMID:25289180

  13. Ankle variability is amplified in older adults due to lower EMG power from 30-60 Hz.

    PubMed

    Kwon, MinHyuk; Baweja, Harsimran S; Christou, Evangelos A

    2012-12-01

    The purpose of this study was to determine the neuromuscular mechanisms of the involved muscles that contribute to the greater positional variability at the ankle joint in older adults compared with young adults. Eleven young adults (25.6±4.9 years) and nine older adults (76.9±5.9 years) were asked to accurately match and maintain a horizontal target line with 5° dorsiflexion of their ankle for 20 s. The loads were 5 and 15% of the one repetition maximum load (1 RM). The visual gain was kept constant at 1° for all trials. Positional variability was quantified as the standard deviation (SD) of the detrended position signal. The neural activation of the tibialis anterior and soleus muscles was quantified as the normalized EMG amplitude, power spectrum density (PSD; EMG oscillations) and coactivation of the two muscles. As expected, positional variability was greater in older adults (older: 0.11±0.06° vs. young: 0.04±0.02°; p=.003). The only significant neural difference occurred for the PSD of the tibialis anterior muscle, where young adults exhibited significantly greater power than older adults from 30-60 Hz. The amplified positional variability of ankle joint in older adults was associated with lower power from 30-60 Hz oscillations in the tibialis anterior muscle (r(2)=.3, p=.01). These results provide novel evidence that older adults exhibit greater positional variability with the ankle joint relative to young adults likely due to their inability to activate the tibialis anterior muscle from 30-60 Hz.

  14. Ankle variability is amplified in older adults due to lower EMG power from 30-60 Hz.

    PubMed

    Kwon, MinHyuk; Baweja, Harsimran S; Christou, Evangelos A

    2012-12-01

    The purpose of this study was to determine the neuromuscular mechanisms of the involved muscles that contribute to the greater positional variability at the ankle joint in older adults compared with young adults. Eleven young adults (25.6±4.9 years) and nine older adults (76.9±5.9 years) were asked to accurately match and maintain a horizontal target line with 5° dorsiflexion of their ankle for 20 s. The loads were 5 and 15% of the one repetition maximum load (1 RM). The visual gain was kept constant at 1° for all trials. Positional variability was quantified as the standard deviation (SD) of the detrended position signal. The neural activation of the tibialis anterior and soleus muscles was quantified as the normalized EMG amplitude, power spectrum density (PSD; EMG oscillations) and coactivation of the two muscles. As expected, positional variability was greater in older adults (older: 0.11±0.06° vs. young: 0.04±0.02°; p=.003). The only significant neural difference occurred for the PSD of the tibialis anterior muscle, where young adults exhibited significantly greater power than older adults from 30-60 Hz. The amplified positional variability of ankle joint in older adults was associated with lower power from 30-60 Hz oscillations in the tibialis anterior muscle (r(2)=.3, p=.01). These results provide novel evidence that older adults exhibit greater positional variability with the ankle joint relative to young adults likely due to their inability to activate the tibialis anterior muscle from 30-60 Hz. PMID:23089330

  15. Intermediate-Term Follow-up After Ankle Distraction for Treatment of End-Stage Osteoarthritis

    PubMed Central

    Nguyen, Mai P.; Pedersen, Douglas R.; Gao, Yubo; Saltzman, Charles L.; Amendola, Annunziato

    2015-01-01

    Background: Treatment of end-stage ankle osteoarthritis remains challenging, especially in young patients. Initial reports have shown early benefits of joint distraction for the treatment of ankle osteoarthritis. We report the five to ten-year results of a previously described patient cohort following ankle distraction surgery. Methods: All thirty-six patients who had undergone ankle distraction surgery between December 2002 and October 2006 were contacted. Patients were evaluated by a clinical investigator and completed the Ankle Osteoarthritis Scale (AOS) and Short Form-36 (SF-36) surveys. Radiographs as well as computed tomography and magnetic resonance imaging scans of the ankles were obtained at the follow-up visits. Results: Twenty-nine patients (81%) were followed for a minimum of five years (mean and standard deviation, 8.3 ± 2.2 years). Sixteen (55%) of the twenty-nine patients still had the native ankle joint whereas thirteen patients (45%) had undergone either ankle arthrodesis or total ankle arthroplasty. Positive predictors of ankle survival included a better AOS score at two years (hazard ratio [HR] = 0.048, 95% confidence interval [CI] = 0.0028 to 0.84, p = 0.04), older age at surgery (HR = 0.91, 95% CI = 0.83 to 0.99, p = 0.04), and fixed distraction (HR = 0.094, 95% CI = 0.017 to 0.525, p < 0.01). Radiographs and advanced imaging revealed progression of ankle osteoarthritis at the time of final follow-up. Conclusions: Ankle function following joint distraction declines over time. Patients should be well informed of the commitment that they must make during the treatment period as well as the long-term results after surgery. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. PMID:25834084

  16. Autogenic EMG-controlled functional electrical stimulation for ankle dorsiflexion control.

    PubMed

    Yeom, Hojun; Chang, Young-Hui

    2010-10-30

    Our objectives were to develop and test a new system for the potential for stable, real-time cancellation of residual stimulation artefacts (RSA) using surface electrode autogenic electromyography-controlled functional electrical stimulator (aEMGcFES). This type of closed-loop FES could be used to provide more natural, continuous control of lower extremity paretic muscles. We built upon work that has been done in the field of FES with one major technological innovation, an adaptive Gram-Schmidt filtering algorithm, which allowed us to digitally cancel RSA in real-time. This filtering algorithm resulted in a stable real-time estimation of the volitional intent of the stimulated muscle, which then acted as the direct signal for continuously controlling homonymous muscle stimulation. As a first step toward clinical application, we tested the viability of our aEMGcFES system to continuously control ankle dorsiflexion in a healthy subject. Our results indicate positively that an aEMGcFES device with adaptive filtering can respond proportionally to voluntary EMG and activate forceful movements to assist dorsiflexion during controlled isometric activation at the ankle. We also verified that normal ankle joint range of movement could be maintained while using the aEMGcFES system. We suggest that real-time cancellation of both primary and RSA is possible with surface electrode aEMGcFES in healthy subjects and shows promising potential for future clinical application to gait pathologies such as drop foot related to hemiparetic stroke.

  17. Autogenic EMG-Controlled Functional Electrical Stimulation for Ankle Dorsiflexion Control

    PubMed Central

    Yeom, Hojun; Chang, Young-Hui

    2010-01-01

    Our objectives were to develop and test a new system for the potential for stable, real-time cancellation of residual stimulation artefacts (RSA) using surface electrode autogenic electromyography-controlled functional electrical stimulator (aEMGcFES). This type of closed-loop FES could be used to provide more natural, continuous control of lower extremity paretic muscles. We built upon work that has been done in the field of FES with one major technological innovation, an adaptive Gram-Schmidt filtering algorithm, which allowed us to digitally cancel RSA in real-time. This filtering algorithm resulted in a stable real-time estimation of the volitional intent of the stimulated muscle, which then acted as the direct signal for continuously controlling homonymous muscle stimulation. As a first step toward clinical application, we tested the viability of our aEMGcFES system to continuously control ankle dorsiflexion in a healthy subject. Our results indicate positively that an aEMGcFES device with adaptive filtering can respond proportionally to voluntary EMG and activate forceful movements to assist dorsiflexion during controlled isometric activation at the ankle. We also verified that normal ankle joint range of movement could be maintained while using the aEMGcFES system. We suggest that real-time cancellation of both primary and RSA is possible with surface electrode aEMGcFES in healthy subjects and shows promising potential for future clinical application to gait pathologies such as drop foot related to hemiparetic stroke. PMID:20713086

  18. Clinical anatomy and biomechanics of the ankle in dance.

    PubMed

    Russell, Jeffrey A; McEwan, Islay M; Koutedakis, Yiannis; Wyon, Matthew A

    2008-01-01

    The ankle is an important joint to understand in the context of dance because it is the connection between the leg and the foot that establishes lower extremity stability. Its function coordinates with the leg and foot and, thus, it is crucial to the dancer's ability to perform. Furthermore, the ankle is one of the most commonly injured body regions in dance. An understanding of ankle anatomy and biomechanics is not only important for healthcare providers working with dancers, but for dance scientists, dance instructors, and dancers themselves. The bony architecture, the soft tissue restraints, and the locomotive structures all integrate to allow the athletic artistry of dance. Yet, there is still much research to be carried out in order to more completely understand the ankle of the dancer.

  19. Foot, leg, and ankle swelling

    MedlinePlus

    Swelling of the ankles - feet - legs; Ankle swelling; Foot swelling; Leg swelling; Edema - peripheral; Peripheral edema ... Painless swelling may affect both legs and may include the calves or ... of gravity makes the swelling most noticeable in the lower ...

  20. Sensitivity of joint moments to changes in walking speed and body-weight-support are interdependent and vary across joints.

    PubMed

    Goldberg, Saryn R; Stanhope, Steven J

    2013-04-01

    We investigated the effect of simultaneous changes in body-weight-support level and walking speed on mean peak internal joint moments at the ankle, knee and hip. We hypothesized that observed changes in these joint moments would be approximately linear with both body-weight-support and walking speed and would be similar across joints. Kinematic and kinetic data were collected from 8 unimpaired adult subjects walking on an instrumented treadmill while wearing a dynamically controlled overhead support harness. Subjects walked with four levels of body-weight-support (0%, 20%, 40%, and 60% of bodyweight) at three walking speeds (0.4, 0.6, and 0.8 statures/s, ranging on average from 0.7 to 1.4m/s). Data were used to calculate mean peak joint moments across subjects for each condition. In general, subjects' mean peak joint moments decreased linearly with decreasing walking speed and with increasing body-weight-support, except the knee extension moment, which showed a quadratic relationship with walking speed and no significant change with body-weight-support. All joint moments, with the exception of knee extension, showed a significant interaction effect between walking speed and body-weight-support, indicating that the sensitivity of these joint moments to changes in these variables was interdependent. In most cases, the ankle and hip extension moments showed the largest sensitivity to walking speed. The ankle moment was observed to have the greatest sensitivity to body-weight-support. This finding, that altering walking speed and body-weight-support level results in non-uniform changes in peak moments across joints, suggests that further research is warranted to establish the set of combined speed and support conditions that produce motor patterns supportive of normal gait retraining.

  1. Joint Inversion of Seismic and Magnetotelluric Data in the Parkfield Region of California Using the Normalized Cross-Gradient Constraint

    NASA Astrophysics Data System (ADS)

    Bennington, Ninfa L.; Zhang, Haijiang; Thurber, Clifford H.; Bedrosian, Paul A.

    2015-05-01

    We present jointly inverted models of P-wave velocity (Vp) and electrical resistivity for a two-dimensional profile centered on the San Andreas Fault Observatory at Depth (SAFOD). Significant structural similarity between main features of the separately inverted Vp and resistivity models is exploited by carrying out a joint inversion of the two datasets using the normalized cross-gradient constraint. This constraint favors structurally similar Vp and resistivity images that adequately fit the seismic and magnetotelluric (MT) datasets. The new inversion code, tomoDDMT, merges the seismic inversion code tomoDD and the forward modeling and sensitivity kernel subroutines of the MT inversion code OCCAM2DMT. TomoDDMT is tested on a synthetic dataset and demonstrates the code's ability to more accurately resolve features of the input synthetic structure relative to the separately inverted resistivity and velocity models. Using tomoDDMT, we are able to resolve a number of key issues raised during drilling at SAFOD. We are able to infer the distribution of several geologic units including the Salinian granitoids, the Great Valley sequence, and the Franciscan Formation. The distribution and transport of fluids at both shallow and great depths is also examined. Low values of velocity/resistivity attributed to a feature known as the Eastern Conductor (EC) can be explained in two ways: the EC is a brine-filled, high porosity region, or this region is composed largely of clay-rich shales of the Franciscan. The Eastern Wall, which lies immediately adjacent to the EC, is unlikely to be a fluid pathway into the San Andreas Fault's seismogenic zone due to its observed higher resistivity and velocity values.

  2. Multivariable dynamic ankle mechanical impedance with relaxed muscles.

    PubMed

    Lee, Hyunglae; Krebs, Hermano Igo; Hogan, Neville

    2014-11-01

    Neurological or biomechanical disorders may distort ankle mechanical impedance and thereby impair locomotor function. This paper presents a quantitative characterization of multivariable ankle mechanical impedance of young healthy subjects when their muscles were relaxed, to serve as a baseline to compare with pathophysiological ankle properties of biomechanically and/or neurologically impaired patients. Measurements using a highly backdrivable wearable ankle robot combined with multi-input multi-output stochastic system identification methods enabled reliable characterization of ankle mechanical impedance in two degrees-of-freedom (DOFs) simultaneously, the sagittal and frontal planes. The characterization included important ankle properties unavailable from single DOF studies: coupling between DOFs and anisotropy as a function of frequency. Ankle impedance in joint coordinates showed responses largely consistent with a second-order system consisting of inertia, viscosity, and stiffness in both seated (knee flexed) and standing (knee straightened) postures. Stiffness in the sagittal plane was greater than in the frontal plane and furthermore, was greater when standing than when seated, most likely due to the stretch of bi-articular muscles (medial and lateral gastrocnemius). Very low off-diagonal partial coherences implied negligible coupling between dorsiflexion-plantarflexion and inversion-eversion. The directions of principal axes were tilted slightly counterclockwise from the original joint coordinates. The directional variation (anisotropy) of ankle impedance in the 2-D space formed by rotations in the sagittal and frontal planes exhibited a characteristic "peanut" shape, weak in inversion-eversion over a wide range of frequencies from the stiffness dominated region up to the inertia dominated region. Implications for the assessment of neurological and biomechanical impairments are discussed.

  3. Mechanics and energetics of incline walking with robotic ankle exoskeletons.

    PubMed

    Sawicki, Gregory S; Ferris, Daniel P

    2009-01-01

    We examined healthy human subjects wearing robotic ankle exoskeletons to study the metabolic cost of ankle muscle-tendon work during uphill walking. The exoskeletons were powered by artificial pneumatic muscles and controlled by the user's soleus electromyography. We hypothesized that as the demand for net positive external mechanical work increased with surface gradient, the positive work delivered by ankle exoskeletons would produce greater reductions in users' metabolic cost. Nine human subjects walked at 1.25 m s(-1) on gradients of 0%, 5%, 10% and 15%. We compared rates of O(2) consumption and CO(2) production, exoskeleton mechanics, joint kinematics, and surface electromyography between unpowered and powered exoskeleton conditions. On steeper inclines, ankle exoskeletons delivered more average positive mechanical power (P<0.0001; +0.37+/-0.03 W kg(-1) at 15% grade and +0.23+/-0.02 W kg(-1) at 0% grade) and reduced subjects' net metabolic power by more (P<0.0001; -0.98+/-0.12 W kg(-1) at 15% grade and -0.45+/-0.07 W kg(-1) at 0% grade). Soleus muscle activity was reduced by 16-25% when wearing powered exoskeletons on all surface gradients (P<0.0008). The ;apparent efficiency' of ankle muscle-tendon mechanical work decreased from 0.53 on level ground to 0.38 on 15% grade. This suggests a decreased contribution from previously stored Achilles' tendon elastic energy and an increased contribution from actively shortening ankle plantar flexor muscle fibers to ankle muscle-tendon positive work during walking on steep uphill inclines. Although exoskeletons delivered 61% more mechanical work at the ankle up a 15% grade compared with level walking, relative reductions in net metabolic power were similar across surface gradients (10-13%). These results suggest a shift in the relative distribution of mechanical power output to more proximal (knee and hip) joints during inclined walking. PMID:19088208

  4. Systematic ankle stabilization and the effect on performance.

    PubMed

    Robinson, J R; Frederick, E C; Cooper, L B

    1986-12-01

    Stabilization of the ankle joint is used as a deterrent to injury, however, insufficient or excessive ankle control can cause negative effects. This study determined the effects of systematic changes in ankle and subtalar joint stabilization on performance through an obstacle course. Data were collected on six subjects as they completed two test procedures. Ankle range of motion in the sagittal and frontal planes was determined using a modified Inman apparatus. Completion time through an obstacle course, set up on a basketball court, was used as a measure of performance. High-top basketball shoes were constructed with pockets which allowed strips of plastic (stiffeners) to be positioned just anterior and posterior to the medial and lateral malleoli. Four shoe conditions were used including the shoe with no stiffeners. Significant differences (P less than 0.05) in eversion, flexion, and inversion were found between the shoe conditions. A general trend of decreased range of motion with increased restriction was observed. Significant differences (P less than 0.05) in performance were found between the shoe conditions, with a general trend of increased times with increased restriction. These results indicate that systematic changes in the range of motion of the ankle and subtalar joints can measurably affect performance. PMID:3784875

  5. Systematic ankle stabilization and the effect on performance.

    PubMed

    Robinson, J R; Frederick, E C; Cooper, L B

    1986-12-01

    Stabilization of the ankle joint is used as a deterrent to injury, however, insufficient or excessive ankle control can cause negative effects. This study determined the effects of systematic changes in ankle and subtalar joint stabilization on performance through an obstacle course. Data were collected on six subjects as they completed two test procedures. Ankle range of motion in the sagittal and frontal planes was determined using a modified Inman apparatus. Completion time through an obstacle course, set up on a basketball court, was used as a measure of performance. High-top basketball shoes were constructed with pockets which allowed strips of plastic (stiffeners) to be positioned just anterior and posterior to the medial and lateral malleoli. Four shoe conditions were used including the shoe with no stiffeners. Significant differences (P less than 0.05) in eversion, flexion, and inversion were found between the shoe conditions. A general trend of decreased range of motion with increased restriction was observed. Significant differences (P less than 0.05) in performance were found between the shoe conditions, with a general trend of increased times with increased restriction. These results indicate that systematic changes in the range of motion of the ankle and subtalar joints can measurably affect performance.

  6. The distribution of cartilage thickness within the joints of the lower limb of elderly individuals

    PubMed Central

    ADAM, CHRISTOPH; ECKSTEIN, FELIX; MILZ, STEFAN; PUTZ, REINHARD

    1998-01-01

    The objective of this study was to investigate the normal distribution of cartilage thickness in the major joints of the lower limb in elderly individuals. A 12.5 MHz ultrasound transducer was used to measure the cartilage thickness in the right and left hip, knee and ankle joint of 10 individuals aged between 62 and 99 y. Distribution patterns of cartilage thickness were derived by b-spline interpolation and the average distribution computed in each surface. The maximum cartilage thickness in the hip joint was 2.6 (±0.36) mm and the mean thickness 1.3 (±0.17) mm. The CV% (a measure of thickness inhomogeneity within the joint surface) was 32%. In the knee, the maximal and mean values were 3.8 (±0.46) mm and 1.9 mm (±0.24) mm, respectively (CV%=34%), and in the ankle 1.7 (±0.25) mm and 1.0 (±0.16) mm (CV%=32%). Systematic differences existed between both sides in the knee, the distal femur showing a significantly greater thickness on the right. While the mean and maximal thicknesses were systematically higher in the knee than in the hip, and in the hip higher than in the ankle (P<0.05), there were no systematic differences in the thickness inhomogeneity of the 3 joints. Only the malleolus showed a somewhat more uniform thickness than the other joint surfaces. The variablity between individuals was similar for all joints for mean thickness, but the interindividual variability of the maximal thickness values was highest in the knee and lowest in the ankle. Whereas the cartilage thickness distributions in the joints of the lower limb have been suggested to reflect the pressure distribution within the articular surface, the absolute thickness is proposed to be a function of dynamic loading (range of motion) during gait, rather than being a reflection of the static articular pressure. PMID:9827636

  7. Technology-enhanced Interactive Teaching of Marginal, Joint and Conditional Probabilities: The Special Case of Bivariate Normal Distribution.

    PubMed

    Dinov, Ivo D; Kamino, Scott; Bhakhrani, Bilal; Christou, Nicolas

    2013-01-01

    Data analysis requires subtle probability reasoning to answer questions like What is the chance of event A occurring, given that event B was observed? This generic question arises in discussions of many intriguing scientific questions such as What is the probability that an adolescent weighs between 120 and 140 pounds given that they are of average height? and What is the probability of (monetary) inflation exceeding 4% and housing price index below 110? To address such problems, learning some applied, theoretical or cross-disciplinary probability concepts is necessary. Teaching such courses can be improved by utilizing modern information technology resources. Students' understanding of multivariate distributions, conditional probabilities, correlation and causation can be significantly strengthened by employing interactive web-based science educational resources. Independent of the type of a probability course (e.g. majors, minors or service probability course, rigorous measure-theoretic, applied or statistics course) student motivation, learning experiences and knowledge retention may be enhanced by blending modern technological tools within the classical conceptual pedagogical models. We have designed, implemented and disseminated a portable open-source web-application for teaching multivariate distributions, marginal, joint and conditional probabilities using the special case of bivariate Normal distribution. A real adolescent height and weight dataset is used to demonstrate the classroom utilization of the new web-application to address problems of parameter estimation, univariate and multivariate inference.

  8. Measurement of T2 value by using 3.0T MRI for patient with ankle arthritis.

    PubMed

    Ahn, Jae Ouk

    2013-01-01

    This study intended to evaluate shape of ankle joint cartilage and damage to the ankle joint cartilage by measuring changes in T2 value of cartilage of healthy people without ankle arthritis and patients with ankle arthritis. The multi-echo technique was used for 20 healthy persons who had no ankle arthritis in the past or in the present clinically and 20 patients who were examined to have ankle arthritis in order to obtain T2 map image of knee joint cartilage. We divided the talotibial joint into medial position, middle position and lateral position to calculate the mean values of T2 in 18 spots that included anterior part, middle part and posterior part of cartilage of neck bone and ankle bone. Mean T2 values were measured in the healthy people group and the ankle arthritis patient group. According to the measurement results, the mean T2 value of the ankle arthritis patient group was measured to be higher than that of the healthy people group.

  9. Managing ankle ligament sprains and tears: current opinion.

    PubMed

    McGovern, Ryan P; Martin, RobRoy L

    2016-01-01

    The purpose of this paper is to present a current review of pathoanatomical features, differential diagnosis, objective assessment, intervention, and clinical course associated with managing lateral ankle ligament sprains. Proper diagnosis and identification of affected structures should be obtained through history and objective assessment. From this information, an individualized evidence-based intervention plan can be developed to enable recovery while decreasing the risk of reinjury. An appropriate evaluation is needed not only to determine the correct diagnosis but also to allow for grading and determining the prognosis of the injury in those with an acute lateral ankle sprain. Examination should include an assessment of impairments as well as a measure of activity and participation. Evidence-based interventions for those with an acute lateral ankle sprain should include weight bearing with bracing, manual therapy, progressive therapeutic exercises, and cryotherapy. For those with chronic ankle instability (CAI), interventions should include manual therapy and a comprehensive rehabilitation program. It is essential to understand the normal clinical course for athletes who sustain a lateral ankle sprain as well as risk factors for an acute injury and CAI. Risk factors for both an acute lateral ankle sprain and CAI include not using an external support and not participating in an appropriate exercise program. Incorporating the latest evidence-based rehabilitation techniques provides the best course of treatment for athletes with an acute ankle sprain or CAI. PMID:27042147

  10. Managing ankle ligament sprains and tears: current opinion

    PubMed Central

    McGovern, Ryan P; Martin, RobRoy L

    2016-01-01

    The purpose of this paper is to present a current review of pathoanatomical features, differential diagnosis, objective assessment, intervention, and clinical course associated with managing lateral ankle ligament sprains. Proper diagnosis and identification of affected structures should be obtained through history and objective assessment. From this information, an individualized evidence-based intervention plan can be developed to enable recovery while decreasing the risk of reinjury. An appropriate evaluation is needed not only to determine the correct diagnosis but also to allow for grading and determining the prognosis of the injury in those with an acute lateral ankle sprain. Examination should include an assessment of impairments as well as a measure of activity and participation. Evidence-based interventions for those with an acute lateral ankle sprain should include weight bearing with bracing, manual therapy, progressive therapeutic exercises, and cryotherapy. For those with chronic ankle instability (CAI), interventions should include manual therapy and a comprehensive rehabilitation program. It is essential to understand the normal clinical course for athletes who sustain a lateral ankle sprain as well as risk factors for an acute injury and CAI. Risk factors for both an acute lateral ankle sprain and CAI include not using an external support and not participating in an appropriate exercise program. Incorporating the latest evidence-based rehabilitation techniques provides the best course of treatment for athletes with an acute ankle sprain or CAI. PMID:27042147

  11. Ankle Arthritis: You Can't Always Replace It.

    PubMed

    Hayes, Brandon J; Gonzalez, Tyler A; Smith, Jeremy T; Chiodo, Christopher P; Bluman, Eric M

    2016-01-01

    End-stage arthritis of the tibiotalar joint is disabling and causes substantial functional impairment. End-stage arthritis of the tibiotalar joint is often the residual effect of a previous traumatic injury. Nonsurgical treatment for end-stage arthritis of the ankle includes bracing, shoe wear modifications, and selective joint injections. For patients who fail to respond to nonsurgical modalities, the two primary treatment options are arthroplasty and arthrodesis. Each treatment option has strong proponents who argue the superiority of their treatment algorithm. Although there is no ideal treatment for ankle arthritis, there are high-quality studies that help guide treatment in patients of varying demographics. Many inherent risks are linked with each treatment option; however, the risks of greatest concern are early implant loosening after arthroplasty that requires revision surgery and the acceleration of adjacent joint degeneration associated with arthrodesis. PMID:27049200

  12. Effects of Prophylactic Ankle Supports on Vertical Ground Reaction Force During Landing: A Meta-Analysis.

    PubMed

    Niu, Wenxin; Feng, Tienan; Wang, Lejun; Jiang, Chenghua; Zhang, Ming

    2016-03-01

    There has been much debate on how prophylactic ankle supports (PASs) may influence the vertical ground reaction force (vGRF) during landing. Therefore, the primary aims of this meta-analysis were to systematically review and synthesize the effect of PASs on vGRF, and to understand how PASs affect vGRF peaks (F1, F2) and the time from initial contact to peak loading (T1, T2) during landing. Several key databases, including Scopus, Cochrane, Embase, PubMed, ProQuest, Medline, Ovid, Web of Science, and the Physical Activity Index, were used for identifying relevant studies published in English since inception to April 1, 2015. The computerized literature search and cross-referencing the citation list of the articles yielded 3,993 articles. Criteria for inclusion required that 1) the study was conducted on healthy adults; 2) the subject number and trial number were known; 3) the subjects performed landing with and without PAS; 4) the landing movement was in the sagittal plane; 5) the comparable vGRF parameters were reported; and 6) the F1 and F2 must be normalized to the subject's body weight. After the removal of duplicates and irrelevant articles, 6, 6, 15 and 11 studies were respectively pooled for outcomes of F1, T1, F2 and T2. This study found a significantly increased F2 (.03 BW, 95% CI: .001, .05) and decreased T1 (-1.24 ms, 95% CI: -1.77, -.71) and T2 (-3.74 ms, 95% CI: -4.83, -2.65) with the use of a PAS. F1 was not significantly influenced by the PAS. Heterogeneity was present in some results, but there was no evidence of publication bias for any outcome. These changes represented deterioration in the buffering characteristics of the joint. An ideal PAS design should limit the excessive joint motion of ankle inversion, while allowing a normal range of motion, especially in the sagittal plane. Key pointsPAS can effectively protect the ligamentous structure from spraining by providing mechanical support and cutaneous proprioceptive benefits.Using of PAS can

  13. Effects of Prophylactic Ankle Supports on Vertical Ground Reaction Force During Landing: A Meta-Analysis

    PubMed Central

    Niu, Wenxin; Feng, Tienan; Wang, Lejun; Jiang, Chenghua; Zhang, Ming

    2016-01-01

    There has been much debate on how prophylactic ankle supports (PASs) may influence the vertical ground reaction force (vGRF) during landing. Therefore, the primary aims of this meta-analysis were to systematically review and synthesize the effect of PASs on vGRF, and to understand how PASs affect vGRF peaks (F1, F2) and the time from initial contact to peak loading (T1, T2) during landing. Several key databases, including Scopus, Cochrane, Embase, PubMed, ProQuest, Medline, Ovid, Web of Science, and the Physical Activity Index, were used for identifying relevant studies published in English since inception to April 1, 2015. The computerized literature search and cross-referencing the citation list of the articles yielded 3,993 articles. Criteria for inclusion required that 1) the study was conducted on healthy adults; 2) the subject number and trial number were known; 3) the subjects performed landing with and without PAS; 4) the landing movement was in the sagittal plane; 5) the comparable vGRF parameters were reported; and 6) the F1 and F2 must be normalized to the subject’s body weight. After the removal of duplicates and irrelevant articles, 6, 6, 15 and 11 studies were respectively pooled for outcomes of F1, T1, F2 and T2. This study found a significantly increased F2 (.03 BW, 95% CI: .001, .05) and decreased T1 (-1.24 ms, 95% CI: -1.77, -.71) and T2 (-3.74 ms, 95% CI: -4.83, -2.65) with the use of a PAS. F1 was not significantly influenced by the PAS. Heterogeneity was present in some results, but there was no evidence of publication bias for any outcome. These changes represented deterioration in the buffering characteristics of the joint. An ideal PAS design should limit the excessive joint motion of ankle inversion, while allowing a normal range of motion, especially in the sagittal plane. Key points PAS can effectively protect the ligamentous structure from spraining by providing mechanical support and cutaneous proprioceptive benefits. Using of PAS can

  14. Diagnostic dilemmas in foot and ankle injuries

    SciTech Connect

    Keene, J.S.; Lange, R.H.

    1986-07-11

    Differential diagnosis of foot and ankle injuries should include (1) stress fractures of the great toe sesamoids, the shaft of the fifth metatarsal, and the tarsal navicular bone; (2) transchondral talar-dome fractures; (3) fractures of the os trigonum; and (4) dislocating peroneal tendons. Diagnosis of these injuries is challenging because the initial roentgenograms often are normal, and special clinical tests and ancillary studies are required.

  15. A Walking Controller for a Powered Ankle Prosthesis

    PubMed Central

    Shultz, Amanda H.; Mitchell, Jason E.; Truex, Don; Lawson, Brian E.; Ledoux, Elissa; Goldfarb, Michael

    2015-01-01

    This paper describes a walking controller implemented on a powered ankle prosthesis prototype and assessed by a below-knee amputee subject on a treadmill at three speeds. The walking controller is a finite state machine which emulates a series of passive impedance functions at the joint in order to reproduce the behavior of a healthy joint. The assessments performed demonstrate the ability of the powered prosthesis prototype and walking controller to reproduce essential biomechanical aspects (i.e. joint angle, torque, and power profiles) of the healthy joint, especially relative to a passive prosthesis. PMID:25571414

  16. A multi-scale finite element model for investigation of chondrocyte mechanics in normal and medial meniscectomy human knee joint during walking.

    PubMed

    Tanska, Petri; Mononen, Mika E; Korhonen, Rami K

    2015-06-01

    Mechanical signals experienced by chondrocytes (articular cartilage cells) modulate cell synthesis and cartilage health. Multi-scale modeling can be used to study how forces are transferred from joint surfaces through tissues to chondrocytes. Therefore, estimation of chondrocyte behavior during certain physical activities, such as walking, could provide information about how cells respond to normal and abnormal loading in joints. In this study, a 3D multi-scale model was developed for evaluating chondrocyte and surrounding peri- and extracellular matrix responses during gait loading within healthy and medial meniscectomy knee joints. The knee joint geometry was based on MRI, whereas the input used for gait loading was obtained from the literature. Femoral and tibial cartilages were modeled as fibril-reinforced poroviscoelastic materials, whereas menisci were considered as transversely isotropic. Fluid pressures in the chondrocyte and cartilage tissue increased up to 2MPa (an increase of 30%) in the meniscectomy joint compared to the normal, healthy joint. The elevated level of fluid pressure was observed during the entire stance phase of gait. A medial meniscectomy caused substantially larger (up to 60%) changes in maximum principal strains in the chondrocyte compared to those in the peri- or extracellular matrices. Chondrocyte volume or morphology did not change substantially due to a medial meniscectomy. Current findings suggest that during walking chondrocyte deformations are not substantially altered due to a medial meniscectomy, while abnormal joint loading exposes chondrocytes to elevated levels of fluid pressure and maximum principal strains (compared to strains in the peri- or extracellular matrices). These might contribute to cell viability and the onset of osteoarthritis.

  17. The mid-term outcome of total ankle arthroplasty and ankle fusion in rheumatoid arthritis: a systematic review

    PubMed Central

    2013-01-01

    Background While arthrodesis is the standard treatment of a severely arthritic ankle joint, total ankle arthroplasty has become a popular alternative. This review provides clinical outcomes and complications of both interventions in patients with rheumatoid arthritis. Methods Studies were obtained from Pubmed, Embase and Web of Science (January 1980 – June 2011) and additional manual search. Inclusion criteria: original clinical study, > 5 rheumatoid arthritis (population), internal fixation arthrodesis or three-component mobile bearing prosthesis (intervention), ankle scoring system (outcome). The clinical outcome score, complication- and failure rates were extracted and the methodological quality of the studies was analysed. Results 17 observational studies of 868 citations were included. The effect size concerning total ankle arthroplasty ranged between 1.9 and 6.0, for arthrodesis the effect sizes were 4.0 and 4.7. Reoperation due to implant failure or reoperation due to non-union, was 11% and 12% for respectively total ankle arthroplasty and arthrodesis. The methodological quality of the studies was low (mean 6.4 out of a maximum of 14 points) and was lower for arthrodesis (mean 4.8) as compared to arthroplasty (mean 7.8) (p = 0.04). Conclusions 17 observational and no (randomized) controlled clinical trials are published on the effectiveness of arthroplasty or arthrodesis of the ankle in rheumatoid arthritis. Regardless of the methodological limitations it can be concluded that both interventions show clinical improvement and in line with current literature neither procedure is superior to the other. PMID:24161014

  18. Effects of 24-week Tai Chi exercise on the knee and ankle proprioception of older women.

    PubMed

    Chang, Shuwan; Zhou, Jihe; Hong, Youlian; Sun, Wei; Cong, Yan; Qin, Meiqin; Lian, Jianhua; Yao, Jian; Li, Weiping

    2016-01-01

    This study examined the effects of regular Tai Chi (TC) exercise on the kinaesthesia of the knee and ankle joints of older women. A total of 43 women aged 55-68 years participated in this study. In a 24-week study period, the TC group (n = 22) underwent an organized TC exercise, whereas the control group (n = 21) maintained a sedentary lifestyle. Customized instruments were used to measure the threshold for the detection of the passive motion of the knee and ankle joints. After 24 weeks, the TC group showed a significantly smaller threshold for the detection of passive motion of knee extension (31.4%, p = 0.009), knee flexion (27.0%, p = 0.044), and ankle dorsal flexion (28.9%, p = 0.014) than the control group. Other comparisons showed no significant differences. The 24-week TC exercise benefited the lower-limb kinaesthesia of the knee joint flexion and extension and ankle dorsal flexion.

  19. Trunk-Rotation Differences at Maximal Reach of the Star Excursion Balance Test in Participants With Chronic Ankle Instability

    PubMed Central

    de la Motte, Sarah; Arnold, Brent L.; Ross, Scott E.

    2015-01-01

    Context: Functional reach on the Star Excursion Balance Test is decreased in participants with chronic ankle instability (CAI). However, comprehensive 3-dimensional kinematics associated with these deficits have not been reported. Objective: To determine if lower extremity kinematics differed in CAI participants during anteromedial, medial, and posteromedial reach on the Star Excursion Balance Test. Design: Case-control study. Setting: Sports medicine research laboratory. Patients or Other Participants: Twenty CAI participants (age = 24.15 ± 3.84 years, height = 168.95 ± 11.57 cm, mass = 68.95 ± 16.29 kg) and 20 uninjured participants (age = 25.65 ± 5.58 years, height = 170.14 ± 8.75 cm, mass = 69.89 ± 10.51 kg) with no history of ankle sprain. We operationally defined CAI as repeated episodes of ankle “giving way” or “rolling over” or both, regardless of neuromuscular deficits or pathologic laxity. All CAI participants scored ≤26 on the Cumberland Ankle Instability Tool. Intervention(s): Star Excursion Balance Test reaches in the anteromedial, medial, and posteromedial directions. The CAI participants used the unstable side as the stance leg. Control participants were sex, height, mass, and side matched to the CAI group. The 3-dimensional kinematics were assessed with a motion-capture system. Main Outcome Measure(s): Group differences on normalized reach distance, trunk, pelvis, and hip-, knee-, and ankle-joint angles at maximum Star Excursion Balance Test reach. Results: No reach-distance differences were detected between CAI and uninjured participants in any of the 3 reach directions. With anteromedial reach, trunk rotation (t1,38 = 3.06, P = .004), pelvic rotation (t1,38 = 3.17, P = .003), and hip flexion (t1,38 = 2.40, P = .002) were greater in CAI participants. With medial reach, trunk flexion (t1,38 = 6.39, P = .05) was greater than for uninjured participants. No differences were seen with posteromedial reach. Conclusions: We did not detect

  20. Simultaneous bilateral total knee and ankle arthroplasty as a single surgical procedure

    PubMed Central

    2011-01-01

    Background Simultaneous osteoarthritis (OA) of the ankle joint complicates primary total knee arthroplasty (TKA). In such cases, rehabilitation of TKA is limited by debilitating ankle pain, but varus or valgus ankle arthritis may even compromise placement of knee prosthetic components. Case presentation We present a patient with simultaneous bilateral valgus and patellofemoral OA of the knees and bilateral varus OA of the ankle joints that equally contributed to overall disability. This 63 years old, motivated and otherwise healthy patient was treated by simultaneous bilateral total knee and ankle arthroplasty (quadruple total joint arthroplasty, TJA) during the same anesthesia. Two years outcome showed excellent alignment and function of all four replaced joints. Postoperative time for rehabilitation, back to work (6th week) and hospital stay (12 days) of this special patient was markedly reduced compared to the usual course of separate TJA. Conclusions Simultaneous quadruple TJA in equally disabling OA of bilateral deformed knees and ankles resulted in a better functional outcome and faster recovery compared to the average reported results after TKA and TAA in literature. However, careful preoperative planning, extensive patient education, and two complete surgical teams were considered essential for successful performance. To the best of our knowledge this is the first case report in literature about quadruple major total joint arthroplasty implanted during the same anesthesia in the same patient. PMID:21995682

  1. Estimation of human ankle impedance during the stance phase of walking.

    PubMed

    Rouse, Elliott J; Hargrove, Levi J; Perreault, Eric J; Kuiken, Todd A

    2014-07-01

    Human joint impedance is the dynamic relationship between the differential change in the position of a perturbed joint and the corresponding response torque; it is a fundamental property that governs how humans interact with their environments. It is critical to characterize ankle impedance during the stance phase of walking to elucidate how ankle impedance is regulated during locomotion, as well as provide the foundation for future development of natural, biomimetic powered prostheses and their control systems. In this study, ankle impedance was estimated using a model consisting of stiffness, damping and inertia. Ankle torque was well described by the model, accounting for 98 ±1.2% of the variance. When averaged across subjects, the stiffness component of impedance was found to increase linearly from 1.5 to 6.5 Nm/rad/kg between 20% and 70% of stance phase. The damping component was found to be statistically greater than zero only for the estimate at 70% of stance phase, with a value of 0.03 Nms/rad/kg. The slope of the ankle's torque-angle curve-known as the quasi-stiffness-was not statistically different from the ankle stiffness values, and showed remarkable similarity. Finally, using the estimated impedance, the specifications for a biomimetic powered ankle prosthesis were introduced that would accurately emulate human ankle impedance during locomotion.

  2. Effects of ankle biofeedback training on strength, balance, and gait in patients with stroke

    PubMed Central

    Kim, Sung-jin; Cho, Hwi-young; Kim, Kyung-hoon; Lee, Suk-min

    2016-01-01

    [Purpose] This study aimed to investigate the effects of ankle biofeedback training on muscle strength of the ankle joint, balance, and gait in stroke patients. [Subjects and Methods] Twenty-seven subjects who had had a stroke were randomly allocated to either the ankle biofeedback training group (n=14) or control group (n=13). Conventional therapy, which adhered to the neurodevelopmental treatment approach, was administered to both groups for 30 minutes. Furthermore, ankle strengthening exercises were performed by the control group and ankle biofeedback training by the experimental group, each for 30 minutes, 5 days a week for 8 weeks. To test muscle strength, balance, and gait, the Biodex isokinetic dynamometer, functional reach test, and 10 m walk test, respectively, were used. [Results] After the intervention, both groups showed a significant increase in muscle strength on the affected side and improved balance and gait. Significantly greater improvements were observed in the balance and gait of the ankle biofeedback training group compared with the control group, but not in the strength of the dorsiflexor and plantar flexor muscles of the affected side. [Conclusion] This study showed that ankle biofeedback training significantly improves muscle strength of the ankle joint, balance, and gait in patients with stroke. PMID:27799701

  3. [Ankle braces prevent ligament injuries].

    PubMed

    Karlsson, Jon

    2002-09-01

    The Cochrane collaboration has performed a meta-analysis of all studies found on the prevention of ankle ligament injuries, frequent in sports like soccer, European handball and basketball. Interventions include the use of modified footwear and associated supports, training programmes and health education. Five randomized trials totalling 3,954 participants were included. With the exception of ankle disc training, all prophylactic interventions entailed the application of an external ankle support in the form of a semi-rigid orthosis, air-cast or high top shoes. The studies showed a significant reduction in the number of ankle sprains in individuals allocated to external ankle support. This reduction was greater for those with a previous history of ankle sprains.

  4. Short-term motor compensations to denervation of feline soleus and lateral gastrocnemius result in preservation of ankle mechanical output during locomotion.

    PubMed

    Prilutsky, Boris I; Maas, Huub; Bulgakova, Margarita; Hodson-Tole, Emma F; Gregor, Robert J

    2011-01-01

    Denervation of selected ankle extensors in animals results in locomotor changes. These changes have been suggested to permit preservation of global kinematic characteristics of the hindlimb during stance. The peak ankle joint moment is also preserved immediately after denervation of several ankle extensors in the cat, suggesting that the animal's response to peripheral nerve injury may also be aimed at preserving ankle mechanical output. We tested this hypothesis by comparing joint moments and power patterns during walking before and after denervation of soleus and lateral gastrocnemius muscles. Hindlimb kinematics, ground reaction forces and electromyographic activity of selected muscles were recorded during level, downslope (-50%) and upslope (50%) walking before and 1-3 weeks after nerve denervation. Denervation resulted in increased activity of the intact medial gastrocnemius and plantaris muscles, greater ankle dorsiflexion, smaller knee flexion, and the preservation of the peak ankle moment during stance. Surprisingly, ankle positive power generated in the propulsion phase of stance was increased (up to 50%) after denervation in all walking conditions (p < 0.05). The obtained results suggest that the short-term motor compensation to denervation of lateral gastrocnemius and soleus muscles may allow for preservation of mechanical output at the ankle. The additional mechanical energy generated at the ankle during propulsion can result, in part, from increased activity of intact synergists, the use of passive tissues around the ankle and by the tendon action of ankle two-joint muscles and crural fascia.

  5. Update on acute ankle sprains.

    PubMed

    Tiemstra, Jeffrey D

    2012-06-15

    Ankle sprains are a common problem seen by primary care physicians, especially among teenagers and young adults. Most ankle sprains are inversion injuries to the lateral ankle ligaments, although high sprains representing damage to the tibiofibular syndesmosis are becoming increasingly recognized. Physicians should apply the Ottawa ankle rules to determine whether radiography is needed. According to the Ottawa criteria, radiography is indicated if there is pain in the malleolar or midfoot zone, and either bone tenderness over an area of potential fracture (i.e., lateral malleolus, medial malleolus, base of fifth metatarsal, or navicular bone) or an inability to bear weight for four steps immediately after the injury and in the emergency department or physician's office. Patients with ankle sprain should use cryotherapy for the first three to seven days to reduce pain and improve recovery time. Patients should wear a lace-up ankle support or an air stirrup brace combined with an elastic compression wrap to reduce swelling and pain, speed recovery, and protect the injured ligaments as they become more mobile. Early mobilization speeds healing and reduces pain more effectively than prolonged rest. Pain control options for patients with ankle sprain include nonsteroidal anti-inflammatory drugs, acetaminophen, and mild opioids. Because a previous ankle sprain is the greatest risk factor for an acute ankle sprain, recovering patients should be counseled on prevention strategies. Ankle braces and supports, ankle taping, a focused neuromuscular training program, and regular sport-specific warm-up exercises can protect against ankle injuries, and should be considered for patients returning to sports or other high-risk activities. PMID:22962897

  6. Vascularized iliac bone graft in cases of ankle tuberculosis.

    PubMed

    Yoshida, Tatsuya; Sakamoto, Akio; Iwamoto, Yukihide

    2009-02-01

    Ankle tuberculosis is a very rare occurrence. Because the ankle is a weightbearing joint, the affected ankle tends to become damaged. Consequently, the surgical procedure of arthrodesis is necessary, which usually proves effective. We report two cases of ankle tuberculosis, in patients 53 and 71 years of age. The former case had been diagnosed initially as osteoarthritis and then later as pyogenic osteomyelitis; the latter case had been diagnosed as pigmented villonodular synovitis, a benign but aggressive lesion that involves the joints. In addition to antitubercular medicine, these cases were treated with debridement for necrotic tissue and arthrodesis. In the former case, an iliac osteocutaneous flap was performed, and arthrodesis between the tibia, talus, and calcaneus was obtained. In the other case, a vascularized iliac bone graft was performed that resulted in arthrodesis between the tarsal bones, talus, and calcaneus but with pseudoarthrosis between the tibia and the talus. Settlement of the joint tuberculosis and gait ability without resorption or corruption of the grafted bone was obtained in both cases. Vascularized bone graft offers the benefits of achieving bone defect reconstruction with promotion of bone union, and the infection can be expected to resolve through medication delivered via the circulation.

  7. Ankle dislocation without accompanying malleolar fracture. A case report.

    PubMed

    Hatori, Masahito; Kotajima, Satoshi; Smith, Richard A; Kokubun, Shoichi

    2006-01-01

    Dislocation of the tibiotalar joint without associated fracture is rare. We present here a 21-year-old man who sustained open posteromedial dislocation of the left ankle without malleolar facture when he jumped and sprained his right ankle while playing basketball. The most likely mechanism is forced flexion applied to the ankle joint leading to a rupture of the anterior capsule and lateral structures of the ankle followed by an accelerating inversion stress leading to a posteromedial dislocation of the talus from the tibial condyle. Transient paresthesia was noted in the area of the superficial peroneal nerve. At surgery, the anterior part of the tibiotalar joint capsule and anterior talofibular ligament were detached from their original sites. The calcaneofibular ligament was also detached with its associated periosteum and a tiny avulsed bony fragment. The articular facets of the tibia and talus were intact. The treatment consisted of wound irrigation, debridement, reduction and capsular suture followed by immobilization with a short leg cast. About 10 degrees of loss in the range of dorsiflexion was observed. The patient achieved good long-term functional results.

  8. US in ankle impingement syndrome.

    PubMed

    Pesquer, Lionel; Guillo, Stephane; Meyer, Philippe; Hauger, Olivier

    2014-06-01

    Ankle impingement is a common condition occurring secondary to sprain or repeated microtrauma. Clinical symptoms are chronic pain located in the affected region and limited range of ankle motion. There are three types of ankle impingement syndrome: anterior impingement, which can be subdivided into anterolateral, anteromedial and purely anterior impingement; posterior impingement, which can be subdivided into posterior and posteromedial impingement; and calcaneal peroneal impingement which is secondary to planovalgus foot deformity. This paper evaluates physiological and clinical elements of these three types of ankle impingement syndrome as well as the role of ultrasound (US) imaging and US-guided treatment.

  9. Short-term ankle motor performance with ankle robotics training in chronic hemiparetic stroke.

    PubMed

    Roy, Anindo; Forrester, Larry W; Macko, Richard F

    2011-01-01

    Cerebrovascular accident (stroke) often results in impaired motor control and persistent weakness that may lead to chronic disability, including deficits in gait and balance function. Finding ways to restore motor control may help reduce these deficits; however, little is known regarding the capacity or temporal profile of short-term motor adaptations and learning at the hemiparetic ankle. Our objective was to determine the short-term effects of a single session of impedance-controlled ankle robot ("anklebot") training on paretic ankle motor control in chronic stroke. This was a double-arm pilot study on a convenience sample of participants with chronic stroke (n = 7) who had residual hemiparetic deficits and an equal number of age- and sex-matched nondisabled control subjects. Training consisted of participants in each group playing a target-based video game with the anklebot for an hour, for a total of 560 movement repetitions in dorsiflexion/plantar flexion ranges followed by retest 48 hours later. Task difficulty was adjusted to ankle range of motion, with robotic assistance decreased incrementally across training. Assessments included robotic measures of ankle motor control on unassisted trials before and after training and at 48 hours after training. Following exposure to the task, subjects with stroke improved paretic ankle motor control across a single training session as indexed by increased targeting accuracy (21.6 +/- 8.0 to 31.4 +/- 4.8, p = 0.05), higher angular speeds (mean: 4.7 +/- 1.5 degrees/s to 6.5 +/- 2.6 degrees/s, p < 0.01, peak: 42.8 +/- 9.0 degrees/s to 45.6 +/- 9.4 degrees/s, p = 0.03), and smoother movements (normalized jerk: 654.1 +/- 103.3 s(-2) to 537.6 +/- 86.7 s(-2), p < 0.005, number of speed peaks: 27.1 +/- 5.8 to 23.7 +/- 4.1, p < 0.01). In contrast, nondisabled subjects did not make statistically significant gains in any metric after training except in the number of successful passages (32.3 +/- 7.5 to 36.5 +/- 6.4, p = 0

  10. A mechanical supination sprain simulator for studying ankle supination sprain kinematics.

    PubMed

    Chan, Yue-Yan; Fong, Daniel Tik-Pui; Yung, Patrick Shu-Hang; Fung, Kwai-Yau; Chan, Kai-Ming

    2008-08-01

    This study presents a free-fall mechanical supination sprain simulator for evaluating the ankle joint kinematics during a simulated ankle supination sprain injury. The device allows the foot to be in an anatomical position before the sudden motion, and also allows different degrees of supination, or a combination of inversion and plantarflexion. Five subjects performed simulated supination sprain trials in five different supination angles. Ankle motion was captured by a motion analysis system, and the ankle kinematics were reported in plantarflexion/dorsiflexion, inversion/eversion and internal/external rotation planes. Results showed that all sprain motions were not pure single-plane motions but were accompanied by motion in other two planes, therefore, different degrees of supination were achieved. The presented sprain simulator allows a more comprehensive study of the kinematics of ankle sprain when compared with some previous laboratory research designs.

  11. Irreducible ankle fracture-dislocation due to tibialis anterior subluxation: a case report.

    PubMed

    Natoli, Roman M; Summers, Hobie D

    2015-01-01

    Irreducible ankle fracture-dislocations are rare. Several cases of irreducible ankle fracture-dislocation have been reported in published studies secondary to the tibialis posterior tendon, deltoid ligament, or extensor digitorum longus tendon blocking the reduction. We report a case of irreducible ankle fracture-dislocation resulting from posteromedial subluxation of the tibialis anterior tendon around a medial malleolar fracture fragment. Ultimately, the ankle required open reduction of the incarcerated tendon to reduce the joint and proceed with internal fixation of the associated fracture. The patient's postoperative course was uncomplicated, and the tibialis anterior tendon was functioning at 10 months postoperatively, after which he did not return for follow-up examinations. To our knowledge, this is the first reported case of the tibialis anterior tendon blocking closed reduction of an ankle fracture-dislocation. PMID:25618805

  12. Lyme arthritis of the pediatric ankle.

    PubMed

    Aiyer, Amiethab; Walrath, Jessica; Hennrikus, William

    2014-10-01

    Lyme arthritis results from acute inflammation caused by the spirochete Borrelia burgdorferi. The number of cases per year has been rising since 2006, with a majority of patients being affected in the northeastern United States. Development of Lyme arthritis is of particular importance to the orthopedic surgeon because Lyme arthritis often presents as an acute episode of joint swelling and tenderness and may be confused with bacterial septic arthritis. Considering the vast difference in treatment management between these 2 pathologies, differentiating between them is of critical importance. Septic arthritis often needs to be addressed surgically, whereas Lyme arthritis can be treated with oral antibiotics alone. Laboratory testing for Lyme disease often results in a delay in diagnosis because many laboratories batch-test Lyme specimens only a few times per week because of increased expense. The authors present a case of Lyme arthritis in the pediatric ankle in an endemic region. No clear algorithm exists to delineate between septic arthritis and Lyme arthritis of the joint. Improved clinical guidelines for the identification and diagnosis of Lyme arthritis of the ankle are important so that appropriate antibiotics can be used and surgery can be avoided.

  13. Time-Varying Ankle Mechanical Impedance During Human Locomotion.

    PubMed

    Lee, Hyunglae; Hogan, Neville

    2015-09-01

    In human locomotion, we continuously modulate joint mechanical impedance of the lower limb (hip, knee, and ankle) either voluntarily or reflexively to accommodate environmental changes and maintain stable interaction. Ankle mechanical impedance plays a pivotal role at the interface between the neuro-mechanical system and the physical world. This paper reports, for the first time, a characterization of human ankle mechanical impedance in two degrees-of-freedom simultaneously as it varies with time during walking. Ensemble-based linear time-varying system identification methods implemented with a wearable ankle robot, Anklebot, enabled reliable estimation of ankle mechanical impedance from the pre-swing phase through the entire swing phase to the early-stance phase. This included heel-strike and toe-off, key events in the transition from the swing to stance phase or vice versa. Time-varying ankle mechanical impedance was accurately approximated by a second order model consisting of inertia, viscosity, and stiffness in both inversion-eversion and dorsiflexion-plantarflexion directions, as observed in our previous steady-state dynamic studies. We found that viscosity and stiffness of the ankle significantly decreased at the end of the stance phase before toe-off, remained relatively constant across the swing phase, and increased around heel-strike. Closer investigation around heel-strike revealed that viscosity and stiffness in both planes increased before heel-strike occurred. This finding is important evidence of "pretuning" by the central nervous system. In addition, viscosity and stiffness were greater in the sagittal plane than in the frontal plane across all subgait phases, except the early stance phase. Comparison with previous studies and implications for clinical study of neurologically impaired patients are provided.

  14. Diagnosing, planning and evaluating osteochondral ankle defects with imaging modalities

    PubMed Central

    van Bergen, Christiaan JA; Gerards, Rogier M; Opdam, Kim TM; Terra, Maaike P; Kerkhoffs, Gino MMJ

    2015-01-01

    This current concepts review outlines the role of different imaging modalities in the diagnosis, preoperative planning, and follow-up of osteochondral ankle defects. An osteochondral ankle defect involves the articular cartilage and subchondral bone (usually of the talus) and is mostly caused by an ankle supination trauma. Conventional radiographs are useful as an initial imaging tool in the diagnostic process, but have only moderate sensitivity for the detection of osteochondral defects. Computed tomography (CT) and magnetic resonance imaging (MRI) are more accurate imaging modalities. Recently, ultrasonography and single photon emission CT have been described for the evaluation of osteochondral talar defects. CT is the most valuable modality for assessing the exact location and size of bony lesions. Cartilage and subchondral bone damage can be visualized using MRI, but the defect size tends to be overestimated due to bone edema. CT with the ankle in full plantar flexion has been shown a reliable tool for preoperative planning of the surgical approach. Postoperative imaging is useful for objective assessment of repair tissue or degenerative changes of the ankle joint. Plain radiography, CT and MRI have been used in outcome studies, and different scoring systems are available. PMID:26716090

  15. Is Hardware Removal Recommended after Ankle Fracture Repair?

    PubMed Central

    Jung, Hong-Geun; Kim, Jin-Il; Park, Jae-Yong; Park, Jong-Tae; Eom, Joon-Sang

    2016-01-01

    The indications and clinical necessity for routine hardware removal after treating ankle or distal tibia fracture with open reduction and internal fixation are disputed even when hardware-related pain is insignificant. Thus, we determined the clinical effects of routine hardware removal irrespective of the degree of hardware-related pain, especially in the perspective of patients' daily activities. This study was conducted on 80 consecutive cases (78 patients) treated by surgery and hardware removal after bony union. There were 56 ankle and 24 distal tibia fractures. The hardware-related pain, ankle joint stiffness, discomfort on ambulation, and patient satisfaction were evaluated before and at least 6 months after hardware removal. Pain score before hardware removal was 3.4 (range 0 to 6) and decreased to 1.3 (range 0 to 6) after removal. 58 (72.5%) patients experienced improved ankle stiffness and 65 (81.3%) less discomfort while walking on uneven ground and 63 (80.8%) patients were satisfied with hardware removal. These results suggest that routine hardware removal after ankle or distal tibia fracture could ameliorate hardware-related pain and improves daily activities and patient satisfaction even when the hardware-related pain is minimal.

  16. Lateral ankle stabilization. Modified Lee and Chrisman-Snook.

    PubMed

    Saltrick, K R

    1991-07-01

    Chronic lateral ankle instability is not always a severe disability, but surgical reconstruction may be necessary in patients with instability or when conservative measures fail. Although recent articles by Ahlgren and Larsson and Bergsten et al provide evidence of satisfactory results with late ligamentous repair of chronic ankle instability via imbrication, lateral ankle stabilization procedures that use tenodesing of fasciodesing techniques continue to provide good results. Prolonged disability after acute lateral ankle ligament disruption has been reported in 20% of patients. With long-term instability, uneven stress distribution with recurrent sprains can lead to osteoarthritis. Various methods for evaluation of the chronically unstable ankle include inversion stress testing, anterior drawer sign, arthrography, and tenography. All of these methods are controversial with false negative results, unreliability, and variations in measurements and interpretation being cited. With this in mind, radiographic instability must be correlated with mechanical and clinical instability. Once all of these findings are correlated the physician can determine the appropriate procedure that will provide the patient with long-term stability. Although more recent studies have addressed repair of chronic instability with ligamentous reinforcement or imbrication, these procedures remain controversial in lieu of Freeman's deafferentiation theory with loss of proprioception. There is also mechanical instability of the subtalar joint, which may also require stabilization. Use of the modified Lee and the Chrisman-Snook techniques as described have provided good results.

  17. [PARTICULAR QUALITIES OF DIAGNOSTIC ACUTE LATERAL ANKLE LIGAMENT INJURIES].

    PubMed

    Krasnoperov, S N; Shishka, I V; Golovaha, M L

    2015-01-01

    Delayed diagnosis of acute lateral ankle ligaments injury and subsequent inadequate treatment leads to the development of chronic instability and rapid progression of degenerative processes in the joint. The aim of our work was to improve treatment results by developing an diagnostic algorithm and treatment strategy of acute lateral ankle ligament injuries. The study included 48 patients with history of acute inversion ankle injury mechanism. Diagnostic protocol included clinical and radiological examination during 48 hours and after 7-10 days after injury. According to the high rate of inaccurate clinical diagnosis in the first 48 hours of the injury a short course of conservative treatment for 7-10 days is needed with follow-up and controlling clinical and radiographic instability tests. Clinical symptoms of ankle inversion injury showed that the combination of local tenderness in the projection of damaged ligaments, the presence of severe periarticular hematoma in the lateral department and positive anterior drawer and talar tilt tests in 7-10 days after the injury in 87% of cases shows the presence of ligament rupture. An algorithm for diagnosis of acute lateral ankle ligament injury was developed, which allowed us to determine differential indications for surgical repair of the ligaments and conservative treatment of these patients.

  18. Diagnosing, planning and evaluating osteochondral ankle defects with imaging modalities.

    PubMed

    van Bergen, Christiaan Ja; Gerards, Rogier M; Opdam, Kim Tm; Terra, Maaike P; Kerkhoffs, Gino Mmj

    2015-12-18

    This current concepts review outlines the role of different imaging modalities in the diagnosis, preoperative planning, and follow-up of osteochondral ankle defects. An osteochondral ankle defect involves the articular cartilage and subchondral bone (usually of the talus) and is mostly caused by an ankle supination trauma. Conventional radiographs are useful as an initial imaging tool in the diagnostic process, but have only moderate sensitivity for the detection of osteochondral defects. Computed tomography (CT) and magnetic resonance imaging (MRI) are more accurate imaging modalities. Recently, ultrasonography and single photon emission CT have been described for the evaluation of osteochondral talar defects. CT is the most valuable modality for assessing the exact location and size of bony lesions. Cartilage and subchondral bone damage can be visualized using MRI, but the defect size tends to be overestimated due to bone edema. CT with the ankle in full plantar flexion has been shown a reliable tool for preoperative planning of the surgical approach. Postoperative imaging is useful for objective assessment of repair tissue or degenerative changes of the ankle joint. Plain radiography, CT and MRI have been used in outcome studies, and different scoring systems are available.

  19. Soft Tissue Impingement of the Ankle: Pathophysiology, Evaluation, and Arthroscopic Treatment.

    PubMed

    Shane, Amber M; Reeves, Christopher L; Vazales, Ryan; Farley, Zachary

    2016-10-01

    Soft tissue impingement (STI) syndrome is one of 3 causes of a larger all-encompassing joint impingement pathologic condition, which also includes bone and neuropathic entrapment. Altered joint biomechanics and friction of joint tissues combine to cause chronic pain and often functional instability. Although the most common form of STI to the ankle is anterolateral in location, posterior and anteromedial impingement is also discussed in this article. Furthermore, a discussion of biomechanical deficiencies and how they may effect location and cause of STI of the ankle is explored along with pathophysiology, clinical and diagnostic evaluation, current treatments, and long-term outcomes. PMID:27599436

  20. State of the art review of knee-ankle-foot orthoses.

    PubMed

    Tian, Feng; Hefzy, Mohamed Samir; Elahinia, Mohammad

    2015-02-01

    Knee-ankle-foot orthoses (KAFOs) are used to assist in ambulation. The purpose of this paper is to review existing KAFO designs which can be grouped into passive KAFOs, stance control (SC) KAFOs, and dynamic KAFOs. The conventional passive KAFOs do not provide any active control for knee motions. SCKAFOs lock the knee joint during the stance phase and allow free rotations during the swing phase. Some SCKAFOs switch between the stance and swing phases using body posture, while others use some kind of a control system to perform this switch. Finally, dynamic KAFOs control the knee joint during both stance and swing phases. Four dynamic systems are identified in the literature that use pneumatics, linear springs, hydraulics, and torsional rods made of superelastic alloys to control the knee joint during the gait cycle. However, only the two systems that use linear springs and torsional rods can reproduce the normal knee stiffness pattern which has two distinct characteristics: a soft stiffness during the swing phase and a hard stiffness during the stance phase. This review indicates that there is a need to conduct research regarding new KAFO designs that duplicate normal knee function during the whole gait cycle.

  1. Propulsion System with Pneumatic Artificial Muscles for Powering Ankle-Foot Orthosis

    NASA Astrophysics Data System (ADS)

    Veneva, Ivanka; Vanderborght, Bram; Lefeber, Dirk; Cherelle, Pierre

    2013-12-01

    The aim of this paper is to present the design of device for control of new propulsion system with pneumatic artificial muscles. The propulsion system can be used for ankle joint articulation, for assisting and rehabilitation in cases of injured ankle-foot complex, stroke patients or elderly with functional weakness. Proposed device for control is composed by microcontroller, generator for muscles contractions and sensor system. The microcontroller receives the control signals from sensors and modulates ankle joint flex- ion and extension during human motion. The local joint control with a PID (Proportional-Integral Derivative) position feedback directly calculates desired pressure levels and dictates the necessary contractions. The main goal is to achieve an adaptation of the system and provide the necessary joint torque using position control with feedback.

  2. The effect of Q angle on ankle sprain occurrence.

    PubMed

    Pefanis, Nikolaos; Papaharalampous, Xenofon; Tsiganos, Georgios; Papadakou, Eugenia; Baltopoulos, Panagiotis

    2009-02-01

    The intersegmental joint forces and the structures that must resist them (articular surfaces, ligaments, and musculature) are related through anatomical alignment of the joints and skeletal system. Ankle joint structure can affect or be affected by bony malformations of the surrounding areas, including the knee and hip. The aim of the current study is to examine the possible relationship between the quadriceps (Q) angle and other factors (anthropometric characteristics, medical history, and age) on the occurrence of ankle sprains, because its value, when assessed correctly, provides useful information for the anatomical alignment of the lower extremity. The study sample consisted of 45 high-level athletes, evenly distributed among 3 sports (basketball, soccer, and volleyball). Q angle measurements were made on radiographs. The study lasted for 2 years. A logistic regression was used to determine the importance of each factor on the probability in question. A significance level of P = .1 was used. The factors contributing more to an ankle sprain were a previous injury of the same type ( P < .01) followed by body mass index (BMI; P < .10) and age (P < .10). On the contrary, Q angle was proven to be statistically nonsignificant (P > .10). The results were valid even when the BMI variable was substituted by body inertia propensity, a derived variable. The Q angle remained statistically nonsignificant ( P > .10). The Q angle magnitude does not seem to be a decisive factor that could increase the probability of spraining an ankle. The most important factors that could affect the probability of sustaining an ankle sprain are the athlete's age, anthropometric characteristics, and prior injuries. PMID:19825746

  3. The effect of Q angle on ankle sprain occurrence.

    PubMed

    Pefanis, Nikolaos; Papaharalampous, Xenofon; Tsiganos, Georgios; Papadakou, Eugenia; Baltopoulos, Panagiotis

    2009-02-01

    The intersegmental joint forces and the structures that must resist them (articular surfaces, ligaments, and musculature) are related through anatomical alignment of the joints and skeletal system. Ankle joint structure can affect or be affected by bony malformations of the surrounding areas, including the knee and hip. The aim of the current study is to examine the possible relationship between the quadriceps (Q) angle and other factors (anthropometric characteristics, medical history, and age) on the occurrence of ankle sprains, because its value, when assessed correctly, provides useful information for the anatomical alignment of the lower extremity. The study sample consisted of 45 high-level athletes, evenly distributed among 3 sports (basketball, soccer, and volleyball). Q angle measurements were made on radiographs. The study lasted for 2 years. A logistic regression was used to determine the importance of each factor on the probability in question. A significance level of P = .1 was used. The factors contributing more to an ankle sprain were a previous injury of the same type ( P < .01) followed by body mass index (BMI; P < .10) and age (P < .10). On the contrary, Q angle was proven to be statistically nonsignificant (P > .10). The results were valid even when the BMI variable was substituted by body inertia propensity, a derived variable. The Q angle remained statistically nonsignificant ( P > .10). The Q angle magnitude does not seem to be a decisive factor that could increase the probability of spraining an ankle. The most important factors that could affect the probability of sustaining an ankle sprain are the athlete's age, anthropometric characteristics, and prior injuries.

  4. Quantitative characterization of brain β-amyloid in 718 normal subjects using a joint PiB/FDG PET image histogram

    NASA Astrophysics Data System (ADS)

    Camp, Jon J.; Hanson, Dennis P.; Lowe, Val J.; Kemp, Bradley J.; Senjem, Matthew L.; Murray, Melissa E.; Dickson, Dennis W.; Parisi, Joseph E.; Petersen, Ronald C.; Robb, Richard A.; Holmes, David R.

    2016-03-01

    We have previously described an automated system for the co-registration of PiB and FDG PET images with structural MRI and a neurological anatomy atlas to produce region-specific quantization of cortical activity and amyloid burden. We also reported a global joint PiB/FDG histogram-based measure (FDG-Associated PiB Uptake Ratio - FAPUR) that performed as well as regional PiB ratio in stratifying Alzheimer's disease (AD) and Lewy Body Dementia (LBD) patients from normal subjects in an autopsy-verified cohort of 31. In this paper we examine results of this analysis on a clinically-verified cohort of 718 normal volunteers. We found that the global FDG ratio correlated negatively with age (r2 = 0.044) and global PiB ratio correlated positively with age (r2=0.038). FAPUR also correlated negatively with age (r2-.025), and in addition, we introduce a new metric - the Pearson's correlation coefficient (r2) of the joint PiB/FDG histogram which correlates positively (r2=0.014) with age. We then used these measurements to construct age-weighted Z-scores for all measurements made on the original autopsy cohort. We found similar stratification using Z-scores compared to raw values; however, the joint PiB/FDG r2 Z-score showed the greatest stratification ability.

  5. Rotational stiffness of American football shoes affects ankle biomechanics and injury severity.

    PubMed

    Button, Keith D; Braman, Jerrod E; Davison, Mark A; Wei, Feng; Schaeffer, Maureen C; Haut, Roger C

    2015-06-01

    While previous studies have investigated the effect of shoe-surface interaction on injury risk, few studies have examined the effect of rotational stiffness of the shoe. The hypothesis of the current study was that ankles externally rotated to failure in shoes with low rotational stiffness would allow more talus eversion than those in shoes with a higher rotational stiffness, resulting in less severe injury. Twelve (six pairs) cadaver lower extremities were externally rotated to gross failure while positioned in 20 deg of pre-eversion and 20 deg of predorsiflexion by fixing the distal end of the foot, axially loading the proximal tibia, and internally rotating the tibia. One ankle in each pair was constrained by an American football shoe with a stiff upper, while the other was constrained by an American football shoe with a flexible upper. Experimental bone motions were input into specimen-specific computational models to examine levels of ligament elongation to help understand mechanisms of ankle joint failure. Ankles in flexible shoes allowed 6.7±2.4 deg of talus eversion during rotation, significantly greater than the 1.7±1.0 deg for ankles in stiff shoes (p = 0.01). The significantly greater eversion in flexible shoes was potentially due to a more natural response of the ankle during rotation, possibly affecting the injuries that were produced. All ankles failed by either medial ankle injury or syndesmotic injury, or a combination of both. Complex (more than one ligament or bone) injuries were noted in 4 of 6 ankles in stiff shoes and 1 of 6 ankles in flexible shoes. Ligament elongations from the computational model validated the experimental injury data. The current study suggested flexibility (or rotational stiffness) of the shoe may play an important role in both the severity of ankle injuries for athletes.

  6. Total ankle replacement or ankle fusion in painful advanced hemophilic arthropathy of the ankle.

    PubMed

    Rodriguez-Merchan, E Carlos

    2015-12-01

    In advanced painful hemophilic arthropathy of the ankle, the last resort is surgical treatment (ankle arthrodesis [AA] or total ankle replacement [TAR]). There is a controversy in the literature on which of the two procedures is more appropriate. A review of the literature was performed to clarify such a controversy. The first search engine was MedLine (keywords: total ankle replacement, ankle arthrodesis). Seventy articles were found in MedLine. Of these, only 16 were selected and reviewed because they were strictly focused on the topic of this article. The second search engine was the Cochrane Library, where only nine systematic reviews were found on the role of TAR and AA in non-hemophilia patients. TAR and AA provide pain relief and patient satisfaction in hemophilia patients in the short term. The available non-hemophilia literature is insufficient to conclude which treatment is superior. My current view is that AA may be preferable in most hemophilia patients.

  7. Management and prevention of acute and chronic lateral ankle instability in athletic patient populations

    PubMed Central

    McCriskin, Brendan J; Cameron, Kenneth L; Orr, Justin D; Waterman, Brian R

    2015-01-01

    Acute and chronic lateral ankle instability are common in high-demand patient populations. If not managed appropriately, patients may experience recurrent instability, chronic pain, osteochondral lesions of the talus, premature osteoarthritis, and other significant long-term disability. Certain populations, including young athletes, military personnel and those involved in frequent running, jumping, and cutting motions, are at increased risk. Proposed risk factors include prior ankle sprain, elevated body weight or body mass index, female gender, neuromuscular deficits, postural imbalance, foot/ankle malalignment, and exposure to at-risk athletic activity. Prompt, accurate diagnosis is crucial, and evidence-based, functional rehabilitation regimens have a proven track record in returning active patients to work and sport. When patients fail to improve with physical therapy and external bracing, multiple surgical techniques have been described with reliable results, including both anatomic and non-anatomic reconstructive methods. Anatomic repair of the lateral ligamentous complex remains the gold standard for recurrent ankle instability, and it effectively restores native ankle anatomy and joint kinematics while preserving physiologic ankle and subtalar motion. Further preventative measures may minimize the risk of ankle instability in athletic cohorts, including prophylactic bracing and combined neuromuscular and proprioceptive training programs. These interventions have demonstrated benefit in patients at heightened risk for lateral ankle sprain and allow active cohorts to return to full activity without adversely affecting athletic performance. PMID:25793157

  8. State-of-the-Art in Ankle Fracture Management in Chile.

    PubMed

    Ortiz, Cristián A; Wagner, Pablo; Wagner, Emilio

    2016-06-01

    The ankle represents the most commonly injured weightbearing joint in the human body. They are typically the result of low-energy, rotational injury mechanisms. However, ankle fractures represent a spectrum of injury patterns from simple to very complex, with varying incidence of posttraumatic arthritis. Stable injury patterns can be treated nonoperatively; unstable injury patterns are typically treated operatively given that they could lead to severe arthritis if not properly addressed. PMID:27261811

  9. Impulsive ankle push-off powers leg swing in human walking.

    PubMed

    Lipfert, Susanne W; Günther, Michael; Renjewski, Daniel; Seyfarth, Andre

    2014-04-15

    Rapid unloading and a peak in power output of the ankle joint have been widely observed during push-off in human walking. Model-based studies hypothesize that this push-off causes redirection of the body center of mass just before touch-down of the leading leg. Other research suggests that work done by the ankle extensors provides kinetic energy for the initiation of swing. Also, muscle work is suggested to power a catapult-like action in late stance of human walking. However, there is a lack of knowledge about the biomechanical process leading to this widely observed high power output of the ankle extensors. In our study, we use kinematic and dynamic data of human walking collected at speeds between 0.5 and 2.5 m s(-1) for a comprehensive analysis of push-off mechanics. We identify two distinct phases, which divide the push-off: first, starting with positive ankle power output, an alleviation phase, where the trailing leg is alleviated from supporting the body mass, and second, a launching phase, where stored energy in the ankle joint is released. Our results show a release of just a small part of the energy stored in the ankle joint during the alleviation phase. A larger impulse for the trailing leg than for the remaining body is observed during the launching phase. Here, the buckling knee joint inhibits transfer of power from the ankle to the remaining body. It appears that swing initiation profits from an impulsive ankle push-off resulting from a catapult without escapement.

  10. Review of control algorithms for robotic ankle systems in lower-limb orthoses, prostheses, and exoskeletons.

    PubMed

    Jiménez-Fabián, R; Verlinden, O

    2012-05-01

    This review focuses on control strategies for robotic ankle systems in active and semiactive lower-limb orthoses, prostheses, and exoskeletons. Special attention is paid to algorithms for gait phase identification, adaptation to different walking conditions, and motion intention recognition. The relevant aspects of hardware configuration and hardware-level controllers are discussed as well. Control algorithms proposed for other actuated lower-limb joints (knee and/or hip), with potential applicability to the development of ankle devices, are also included.

  11. Are Movement Disorders and Sensorimotor Injuries Pathologic Synergies? When Normal Multi-Joint Movement Synergies Become Pathologic

    PubMed Central

    Santello, Marco; Lang, Catherine E.

    2015-01-01

    The intact nervous system has an exquisite ability to modulate the activity of multiple muscles acting at one or more joints to produce an enormous range of actions. Seemingly simple tasks, such as reaching for an object or walking, in fact rely on very complex spatial and temporal patterns of muscle activations. Neurological disorders such as stroke and focal dystonia affect the ability to coordinate multi-joint movements. This article reviews the state of the art of research of muscle synergies in the intact and damaged nervous system, their implications for recovery and rehabilitation, and proposes avenues for research aimed at restoring the nervous system’s ability to control movement. PMID:25610391

  12. Individuals with multiple sclerosis redistribute positive mechanical work from the ankle to the hip during walking.

    PubMed

    Davies, Brenda L; Hoffman, Rashelle M; Kurz, Max J

    2016-09-01

    Individuals with multiple sclerosis (MS) typically walk slower, have reduced cadences and shorter step lengths. While these spatiotemporal gait alterations have been thought to be due to decreased power generation at the ankle, the distribution of mechanical work across the ankle, knee and hip joints during walking is not well understood. By quantifying the mechanical work at each joint, the compensatory mechanisms utilized by individuals with MS to maintain gait speed may be better understood. Fifteen subjects with MS (EDSS: 4.4±1.0) and fifteen healthy age-matched control subjects completed a three-dimensional gait analysis. The net mechanical work at the ankle, knee and hip joints was quantified for the stance phase of gait. Our results found that the less impaired leg of the subjects with MS generated a similar amount of mechanical work as the control group; however, the ankle joint produced less positive mechanical work, and the hip joint generated more positive mechanical work. Additionally, the less impaired leg of the subjects with MS and the leg of the control group generated more positive work than the more impaired leg of the subjects with MS. These outcomes suggest that individuals with MS may adopt a hip compensatory strategy with their less impaired leg during gait due to the limited amount of mechanical work generated at the ankle.

  13. Arthroscopic Repair of Ankle Instability.

    PubMed

    Sorensen, Matthew D; Baca, John; Arbuckle, Keith

    2016-10-01

    Arthroscopic lateral ankle stabilization procedures have been described for many years. New technological advances and a deeper understanding of the pathobiomechanics involved in chronic lateral ankle instability have allowed an expansion of arthroscopic approaches to this common pathology. As experience is gained and outcomes within the patient profile are understood, the authors feel that the arthroscopic approach to lateral ankle stabilization may prove superior to traditional methods secondary to the risk and traditional complications that are mitigated within minimally invasive arthroscopic approaches. Additionally, the arthroscopic approach may allow a quicker return to ballistic sport and decrease time for rehabilitation. PMID:27599440

  14. A Solitary Fibrous Tumor (Cellular Form) of the Ankle.

    PubMed

    Lee, Jun Yong; Kim, Dong-Hwi; Seo, Kyung-Jin; Jung, Sung-No

    2016-01-01

    A solitary fibrous tumor (SFT) is a rare type of mesenchymal tumor composed of uniform spindle cells that is classically described as a patternless feature. SFT normally originates from the pleura, with an SFT originating from skin rarely reported. We report what we believe to be the first case of an SFT arising from the ankle. Our case was confirmed histopathologically with immunohistochemical staining.

  15. Conservative treatments for rheumatoid arthritis in the foot and ankle.

    PubMed

    Anain, Joseph M; Bojrab, Angela R; Rhinehart, Francine C

    2010-04-01

    Rheumatoid arthritis (RA) is a systemic inflammatory disease that attacks peripheral joints, causing their destruction. Several pharmacologic therapies and physical modalities are available for its treatment. Because of the progressive nature of RA, complementary and alternative medicine therapy in conjunction with conventional medicine is administered to patients with RA. This article discusses the presence of undiagnosed RA in the foot and ankle and reviews the concurrent nonoperative measures in treatment, including pharmacologic and physical modalities.

  16. Imaging findings in arthrofibrosis of the ankle and foot.

    PubMed

    Linklater, James M; Fessa, Chris K

    2012-07-01

    Arthrofibrosis is defined as joint pain and stiffness that does not allow functional range of motion and is due to adhesions or contracture of the joint. Arthrofibrosis is characterized by an abnormal proliferation of fibrous tissue that may be focal or diffuse and intra-articular or extra-articular. Trauma and surgery are the most common etiological factors. In the ankle and foot symptomatic arthrofibrosis is not uncommonly seen in the talocrural joint, posterior subtalar joint, and the metatarsophalangeal joints. Imaging can assist with diagnosis and planning treatment, most commonly using MRI and occasionally ultrasound. Typical imaging findings consist of capsular and pericapsular thickening and scarring, best demonstrated on proton-density MR images but also demonstrable on ultrasound.

  17. Ankle Fractures Often Not Diagnosed

    MedlinePlus

    ... side of the ankle. This condition often... Barefoot Running Barefoot running is running while barefoot, without wearing any shoes on the feet. Running in thin-soled, flexible shoes is related but ...

  18. Effects of ankle balance taping with kinesiology tape for a patient with chronic ankle instability

    PubMed Central

    Kim, Byeong-Jo; Lee, Jung-Hoon; Kim, Chang-Tae; Lee, Sun-Min

    2015-01-01

    [Purpose] To report the effects of ankle balance taping for a patient with chronic ankle instability (CAI). [Subject] A 33-year-old man with a 10 year history of chronic ankle stability. [Methods] ABT with kinesiology tape was performed for 2 months (average, 16 h/day) around the right ankle. [Results] At the end of two months, no ankle instability was noted when ascending and descending the stairs, jumping, turning, operating the pedals while driving, and lifting heavy objects. [Conclusion] The repeated use of kinesiology tape in ankle balance taping may be an effective treatment for recovering the ankle stability of patients with chronic ankle instability. PMID:26311206

  19. Effects of ankle balance taping with kinesiology tape for a patient with chronic ankle instability.

    PubMed

    Kim, Byeong-Jo; Lee, Jung-Hoon; Kim, Chang-Tae; Lee, Sun-Min

    2015-07-01

    [Purpose] To report the effects of ankle balance taping for a patient with chronic ankle instability (CAI). [Subject] A 33-year-old man with a 10 year history of chronic ankle stability. [Methods] ABT with kinesiology tape was performed for 2 months (average, 16 h/day) around the right ankle. [Results] At the end of two months, no ankle instability was noted when ascending and descending the stairs, jumping, turning, operating the pedals while driving, and lifting heavy objects. [Conclusion] The repeated use of kinesiology tape in ankle balance taping may be an effective treatment for recovering the ankle stability of patients with chronic ankle instability.

  20. Treatment of common deficits associated with chronic ankle instability.

    PubMed

    Holmes, Alison; Delahunt, Eamonn

    2009-01-01

    Lateral ankle sprains are amongst the most common injuries incurred by athletes, with the high rate of reoccurrence after initial injury becoming of great concern. Chronic ankle instability (CAI) refers to the development of repetitive ankle sprains and persistent residual symptoms post-injury. Some of the initial symptoms that occur in acute sprains may persist for at least 6 months post-injury in the absence of recurrent sprains, despite the athlete having returned to full functional activity. CAI is generally thought to be caused by mechanical instability (MI) or functional instability (FI), or both. Although previously discussed as separate entities, recent research has demonstrated that deficits associated with both MI and FI may co-exist to result in CAI. For clinicians, the main deficits associated with CAI include deficits in proprioception, neuromuscular control, strength and postural control. Based on the literature reviewed, it does seem that subjects with CAI have a deficit in frontal plane ankle joint positional sense. Subjects with CAI do not appear to exhibit any increased latency in the peroneal muscles in response to an external perturbation. Preliminary data suggest that feed-forward neuromuscular control may be more important than feed-back neuromuscular control and interventions are now required to address deficits in feed-forward neuromuscular control. Balance training protocols have consistently been shown to improve postural stability in subjects with CAI. Subjects with CAI do not experience decreased peroneus longus strength, but instead may experience strength deficits in the ankle joint invertor muscles. These findings are of great clinical significance in terms of understanding the mechanisms and deficits associated with CAI. An appreciation of these is vital to allow clinicians to develop effective prevention and treatment programmes in relation to CAI.

  1. Biomechanical Comparison of 3 Ankle Braces With and Without Free Rotation in the Sagittal Plane

    PubMed Central

    Alfuth, Martin; Klein, Dieter; Koch, Raphael; Rosenbaum, Dieter

    2014-01-01

    Context: Various designs of braces including hinged and nonhinged models are used to provide external support of the ankle. Hinged ankle braces supposedly allow almost free dorsiflexion and plantar flexion of the foot in the sagittal plane. It is unclear, however, whether this additional degree of freedom affects the stabilizing effect of the brace in the other planes of motion. Objective: To investigate the dynamic and passive stabilizing effects of 3 ankle braces, 2 hinged models that provide free plantar flexion–dorsiflexion in the sagittal plane and 1 ankle brace without a hinge. Design: Crossover study. Setting: University Movement Analysis Laboratory. Patients or Other Participants: Seventeen healthy volunteers (5 women, 12 men; age = 25.4 ± 4.8 years; height = 180.3 ± 6.5 cm; body mass = 75.5 ± 10.4 kg). Intervention(s): We dynamically induced foot inversion on a tilting platform and passively induced foot movements in 6 directions via a custom-built apparatus in 3 brace conditions and a control condition (no brace). Main Outcome Measure(s): Maximum inversion was determined dynamically using an in-shoe electrogoniometer. Passively induced maximal joint angles were measured using a torque and angle sensor. We analyzed differences among the 4 ankle-brace conditions (3 braces, 1 control) for each of the dependent variables with Friedman and post hoc tests (P < .05). Results: Each ankle brace restricted dynamic foot-inversion movements on the tilting platform as compared with the control condition, whereas only the 2 hinged ankle braces differed from each other, with greater movement restriction caused by the Ankle X model. Passive foot inversion was reduced with all ankle braces. Passive plantar flexion was greater in the hinged models as compared with the nonhinged brace. Conclusions: All ankle braces showed stabilizing effects against dynamic and passive foot inversion. Differences between the hinged braces and the nonhinged brace did not appear to be

  2. Assessing the Relative Contributions of Active Ankle and Knee Assistance to the Walking Mechanics of Transfemoral Amputees Using a Powered Prosthesis

    PubMed Central

    Simon, Ann M.; Hargrove, Levi J.

    2016-01-01

    Powered knee-ankle prostheses are capable of providing net-positive mechanical energy to amputees. Yet, there are limitless ways to deliver this energy throughout the gait cycle. It remains largely unknown how different combinations of active knee and ankle assistance affect the walking mechanics of transfemoral amputees. This study assessed the relative contributions of stance phase knee swing initiation, increasing ankle stiffness and powered plantarflexion as three unilateral transfemoral amputees walked overground at their self-selected walking speed. Five combinations of knee and ankle conditions were evaluated regarding the kinematics and kinetics of the amputated and intact legs using repeated measures analyses of variance. We found eliminating active knee swing initiation or powered plantarflexion was linked to increased compensations of the ipsilateral hip joint during the subsequent swing phase. The elimination of knee swing initiation or powered plantarflexion also led to reduced braking ground reaction forces of the amputated and intact legs, and influenced both sagittal and frontal plane loading of the intact knee joint. Gradually increasing prosthetic ankle stiffness influenced the shape of the prosthetic ankle plantarflexion moment, more closely mirroring the intact ankle moment. Increasing ankle stiffness also corresponded to increased prosthetic ankle power generation (despite a similar maximum stiffness value across conditions) and increased braking ground reaction forces of the amputated leg. These findings further our understanding of how to deliver assistance with powered knee-ankle prostheses and the compensations that occur when specific aspects of assistance are added/removed. PMID:26807889

  3. Assessing the Relative Contributions of Active Ankle and Knee Assistance to the Walking Mechanics of Transfemoral Amputees Using a Powered Prosthesis.

    PubMed

    Ingraham, Kimberly A; Fey, Nicholas P; Simon, Ann M; Hargrove, Levi J

    2016-01-01

    Powered knee-ankle prostheses are capable of providing net-positive mechanical energy to amputees. Yet, there are limitless ways to deliver this energy throughout the gait cycle. It remains largely unknown how different combinations of active knee and ankle assistance affect the walking mechanics of transfemoral amputees. This study assessed the relative contributions of stance phase knee swing initiation, increasing ankle stiffness and powered plantarflexion as three unilateral transfemoral amputees walked overground at their self-selected walking speed. Five combinations of knee and ankle conditions were evaluated regarding the kinematics and kinetics of the amputated and intact legs using repeated measures analyses of variance. We found eliminating active knee swing initiation or powered plantarflexion was linked to increased compensations of the ipsilateral hip joint during the subsequent swing phase. The elimination of knee swing initiation or powered plantarflexion also led to reduced braking ground reaction forces of the amputated and intact legs, and influenced both sagittal and frontal plane loading of the intact knee joint. Gradually increasing prosthetic ankle stiffness influenced the shape of the prosthetic ankle plantarflexion moment, more closely mirroring the intact ankle moment. Increasing ankle stiffness also corresponded to increased prosthetic ankle power generation (despite a similar maximum stiffness value across conditions) and increased braking ground reaction forces of the amputated leg. These findings further our understanding of how to deliver assistance with powered knee-ankle prostheses and the compensations that occur when specific aspects of assistance are added/removed.

  4. Pulsed Shortwave Diathermy and Joint Mobilizations for Achieving Normal Elbow Range of Motion After Injury or Surgery With Implanted Metal: A Case Series

    PubMed Central

    Draper, David O.

    2014-01-01

    Context: Regaining full, active range of motion (ROM) after trauma to the elbow is difficult. Objective: To report the cases of 6 patients who lacked full ROM in the elbow because of trauma. The treatment regimen was thermal pulsed shortwave diathermy and joint mobilizations. Design: Case series. Setting: University therapeutic modalities laboratory. Patients or Other Participants: Six patients (5 women [83%], 1 man [17%]) lacked a mean active ROM of 24.5° of extension approximately 4.8 years after trauma or surgery. Intervention(s): Treatment consisted of 20 minutes of pulsed shortwave diathermy at 800 pulses per second for 400 microseconds (40–48 W average power, 150 W peak power) applied to the cubital fossa, immediately followed by 7 to 8 minutes of joint mobilizations. After posttreatment ROM was recorded, ice was applied to the area for about 30 minutes. Main Outcomes Measure(s): Changes in extension active ROM were assessed before and after each treatment. Once the patient achieved full, active ROM or failed to improve on 2 consecutive visits, he or she was discharged from the study. Results: By the fifth treatment, 4 participants (67%) achieved normal extension active ROM, and 2 of the 4 (50%) exceeded the norm. Five participants (83%) returned to normal activities and full use of their elbows. One month later, the 5 participants had maintained, on average, (mean ± SD) 92% ± 6% of their final measurements. Conclusions: A combination of thermal pulsed shortwave diathermy and joint mobilizations was effective in restoring active ROM of elbow extension in 5 of the 6 patients (83%) who lacked full ROM after injury or surgery. PMID:25485976

  5. Consistent accuracy in whole-body joint kinetics during gait using wearable inertial motion sensors and in-shoe pressure sensors.

    PubMed

    Khurelbaatar, Tsolmonbaatar; Kim, Kyungsoo; Lee, SuKyoung; Kim, Yoon Hyuk

    2015-06-01

    To analyze human motion such as daily activities or sports outside of the laboratory, wearable motion analysis systems have been recently developed. In this study, the joint forces and moments in whole-body joints during gait were evaluated using a wearable motion analysis system consisting of an inertial motion measurement system and an in-shoe pressure sensor system. The magnitudes of the joint forces and the moments in nine joints (cervical, thoracic, lumbar, right shoulder, right elbow, right wrist, right hip, right knee, and right ankle) during gait were calculated using the wearable system and the conventional system, respectively, based on a standard inverse dynamics analysis. The averaged magnitudes of the joint forces and moments of five subjects were compared between the wearable and conventional systems in terms of the Pearson's correlation coefficient and the normalized root mean squared error to the maximum value from the conventional system. The results indicated that both the joint forces and joint moments in human whole body joints using wearable inertial motion sensors and in-shoe pressure sensors were feasible for normal motions with a low speed such as walking, although the lower extremity joints showed the strongest correlation and overall the joint moments were associated with relatively smaller correlation coefficients and larger normalized root mean squared errors in comparison with the joint forces. The portability and mobility of this wearable system can provide wide applicability in both clinical and sports motion analyses. PMID:25957652

  6. Consistent accuracy in whole-body joint kinetics during gait using wearable inertial motion sensors and in-shoe pressure sensors.

    PubMed

    Khurelbaatar, Tsolmonbaatar; Kim, Kyungsoo; Lee, SuKyoung; Kim, Yoon Hyuk

    2015-06-01

    To analyze human motion such as daily activities or sports outside of the laboratory, wearable motion analysis systems have been recently developed. In this study, the joint forces and moments in whole-body joints during gait were evaluated using a wearable motion analysis system consisting of an inertial motion measurement system and an in-shoe pressure sensor system. The magnitudes of the joint forces and the moments in nine joints (cervical, thoracic, lumbar, right shoulder, right elbow, right wrist, right hip, right knee, and right ankle) during gait were calculated using the wearable system and the conventional system, respectively, based on a standard inverse dynamics analysis. The averaged magnitudes of the joint forces and moments of five subjects were compared between the wearable and conventional systems in terms of the Pearson's correlation coefficient and the normalized root mean squared error to the maximum value from the conventional system. The results indicated that both the joint forces and joint moments in human whole body joints using wearable inertial motion sensors and in-shoe pressure sensors were feasible for normal motions with a low speed such as walking, although the lower extremity joints showed the strongest correlation and overall the joint moments were associated with relatively smaller correlation coefficients and larger normalized root mean squared errors in comparison with the joint forces. The portability and mobility of this wearable system can provide wide applicability in both clinical and sports motion analyses.

  7. Alpha 5 Integrin Mediates Osteoarthritic Changes in Mouse Knee Joints

    PubMed Central

    Candela, Maria Elena; Wang, Chao; Gunawardena, Aruni T.; Zhang, Kairui; Cantley, Leslie; Yasuhara, Rika; Usami, Yu; Francois, Noelle; Iwamoto, Masahiro; van der Flier, Arjan; Zhang, Yejia; Qin, Ling; Han, Lin; Enomoto-Iwamoto, Motomi

    2016-01-01

    Osteoarthritis (OA) is one of most common skeletal disorders and can affect synovial joints such as knee and ankle joints. α5 integrin, a major fibronectin receptor, is expressed in articular cartilage and has been demonstrated to play roles in synovial joint development and in the regulation of chondrocyte survival and matrix degradation in articular cartilage. We hypothesized that α5 integrin signaling is involved in pathogenesis of OA. To test this, we generated compound mice that conditionally ablate α5 integrin in the synovial joints using the Gdf5Cre system. The compound mice were born normally and had an overall appearance similar to the control mice. However, when the mutant mice received the OA surgery, they showed stronger resistance to osteoarthritic changes than the control. Specifically the mutant knee joints presented lower levels of cartilage matrix and structure loss and synovial changes and showed stronger biomechanical properties than the control knee joints. These findings indicate that α5 integrin may not be essential for synovial joint development but play a causative role in induction of osteoarthritic changes. PMID:27280771

  8. Alpha 5 Integrin Mediates Osteoarthritic Changes in Mouse Knee Joints.

    PubMed

    Candela, Maria Elena; Wang, Chao; Gunawardena, Aruni T; Zhang, Kairui; Cantley, Leslie; Yasuhara, Rika; Usami, Yu; Francois, Noelle; Iwamoto, Masahiro; van der Flier, Arjan; Zhang, Yejia; Qin, Ling; Han, Lin; Enomoto-Iwamoto, Motomi

    2016-01-01

    Osteoarthritis (OA) is one of most common skeletal disorders and can affect synovial joints such as knee and ankle joints. α5 integrin, a major fibronectin receptor, is expressed in articular cartilage and has been demonstrated to play roles in synovial joint development and in the regulation of chondrocyte survival and matrix degradation in articular cartilage. We hypothesized that α5 integrin signaling is involved in pathogenesis of OA. To test this, we generated compound mice that conditionally ablate α5 integrin in the synovial joints using the Gdf5Cre system. The compound mice were born normally and had an overall appearance similar to the control mice. However, when the mutant mice received the OA surgery, they showed stronger resistance to osteoarthritic changes than the control. Specifically the mutant knee joints presented lower levels of cartilage matrix and structure loss and synovial changes and showed stronger biomechanical properties than the control knee joints. These findings indicate that α5 integrin may not be essential for synovial joint development but play a causative role in induction of osteoarthritic changes. PMID:27280771

  9. TOTAL ANKLE ARTHROPLASTY: BRAZILIAN EXPERIENCE WITH THE HINTEGRA PROSTHESIS.

    PubMed

    Nery, Caio; Fernandes, Túlio Diniz; Réssio, Cibele; Fuchs, Mauro Luiz; Godoy Santos, Alexandre Leme de; Ortiz, Rafael Trevisan

    2010-01-01

    Ankle arthrosis is becoming more and more common. The search for solutions that preserve joint function has led to a new generation of prosthesis with three components and more degrees of freedom. This paper presents the results achieved for ten patients treated with the HINTEGRA Prosthesis (Integra, New Deal), through collaborative action between the Foot and Ankle Groups of the Orthopedics and Traumatology divisions of Escola Paulista de Medicina, Unifesp, and the School of Medicine of the University of São Paulo (USP). The ten patients (six women and four men, aged between 29 and 66 years), underwent a surgical procedure consisting of Hintermann's technique, between January and June 2005. They were evaluated at prearranged intervals, and the data were subjected to statistical analysis. The surgery led to a significant improvement in ankle mobility. Radiological evaluation showed no signs of loosening or failure in the prosthetic components in any of the patients studied. Although the complication rate in our sample was high, it was equivalent to the rates found by other authors, and directly represents the learning curve associate with this kind of procedure. Four years after the procedure, it was found that the patients pain levels had significantly decreased, and that their functional patterns had significantly improved, with AOFAS and Hintermann scores indicating results that were excellent for 20%, good for 70% and poor for 10%. Treatment of ankle arthritis by means of total arthroplasty using the HINTEGRA prosthesis was capable of providing good results over an average observation period of four years.

  10. Measurement of torque during passive and active ankle movements in patients with muscle hypertonia. A methodological study.

    PubMed

    Broberg, C; Grimby, G

    1983-01-01

    Torque curves were recorded during passive and active ankle joint movements at three preset angular velocities (30, 60 and 120 degrees/s) with the subject in the supine position and 45 degrees hip and knee angles. Recordings were performed in normal subjects (n = 11), patients with clinical spasticity (n = 10) and patients with Parkinson's disease (n = 7). The torque curves recorded during passive dorsiflexion followed by plantar flexion showed a counterclockwise hysteresis loop with minimal area in the normal subjects and a large area in patients, especially at the highest velocity. The torque increase during dorsiflexion was proportional to the angular velocity in the patients with spasticity but not in the patients with Parkinson's disease. In the patients with spasticity, a good correlation was found between clinical assessment of hypertonia and measurements of torque during passive movements but not torque values during maximal voluntary dorsiflexion. A model for data reduction and estimation of instant slope values on different parts of the torque-angle curve is suggested. The use of ankle torque recordings for evaluation of treatment effects is exemplified.

  11. Use of Soft-Tissue Procedures for Managing Varus and Valgus Malalignment with Total Ankle Replacement.

    PubMed

    Roukis, Thomas S; Elliott, Andrew D

    2015-10-01

    Achieving frontal plane alignment of the ankle joint during total ankle replacement is essential for long-term success. Tendon and ligament lengthening, ligament reinforcement, tendon transfer, nonanatomic tendon transfer ligament reconstruction, and periarticular osteotomies are safe, straightforward, minimally invasive, and reproducible procedures to correct varus and valgus deformities associated with end-stage degenerative joint disease. Using reproducible topographic anatomic landmarks is essential to these techniques properly and limit complications. The approach to frontal plane deformities is stepwise, with liberal use of tendon and ligament lengthening and reconstruction, a low threshold for nonanatomic tendon transfer ligament reconstructions, and tendon transfers and/or periarticular osteotomies.

  12. The effect of ankle muscle strength and flexibility on dolphin kick performance in competitive swimmers.

    PubMed

    Willems, Tine M; Cornelis, Justien A M; De Deurwaerder, Lien E P; Roelandt, Filip; De Mits, Sophie

    2014-08-01

    The velocity of a swimmer is determined by biomechanical and bioenergetics factors. However, little is known about the effect of ankle flexibility on dolphin kick performance. Next to this, scientific evidence is lacking concerning the influence of ankle muscle strength. Therefore, the aim of this study was to investigate the effect of ankle flexibility and muscle strength on dolphin kick performance in competitive swimmers. Ankle range of motion (ROM) and ankle muscle strength were measured in 26 healthy competitive swimmers. The effect of both was assessed on the swimmer's velocity and lower extremity joint angles during three maximal dolphin kick trials. Additionally, the effect of a flexibility restriction by a tape on the dolphin kick performance was assessed. Correlations were calculated between the flexibility, muscle strength and dolphin kick performance and differences were investigated between the unrestricted and restricted condition. Muscle strength of dorsal flexors and internal rotators were positively significantly correlated with the velocity. Active and passive plantar flexion ROM and internal rotation ROM were not significantly correlated. A plantar flexion-internal rotation restriction during the dolphin kick showed a significant decrease in velocity. This restriction was associated with a changed movement pattern in the knee towards more flexion. The results suggest that dolphin kick velocity might be enhanced by ankle muscle strength exercises and that subjects with a restricted ankle flexibility might profit from a flexibility program. PMID:24984154

  13. Local infiltration of liposome bupivacaine in foot and ankle surgery: case-based reviews.

    PubMed

    Herbst, Steven A

    2014-10-01

    Foot and ankle surgical procedures, ranging from simple procedures, such as bunionectomy and correction of hammer toe, to more complex surgery, such as ankle fusion and ankle replacement, are extremely painful. Moreover, there is increasing interest in performing these procedures in an outpatient setting. Nerve blocks are extensively used in foot and ankle surgery, and commonly used techniques include sciatic nerve block with saphenous nerve augmentation; ankle block; and local, digital, or field block. Whereas more extensive blocks are associated with increased medical risk, higher cost, and delayed ambulation, more local approaches may not provide an adequate duration of effect. EXPAREL® (bupivacaine liposome injectable suspension) is an extended-release local anesthetic that can be infiltrated directly into the surgical site by the orthopedic surgeon to provide continuous and effective analgesia at the site of surgical injury for up to 72 hours. Two cases that illustrate the use of EXPAREL® in foot and ankle surgery are described. The first case involves ankle replacement in an active 58-year-old man with a 20-plus-year history of arthritis. The second case involves a young woman undergoing surgery for a talar neck fracture-dislocation with an open injury, dislocated subtalar joint, avascular talus, and considerable deformity. Both patients reported excellent control of postsurgical pain. PMID:25303454

  14. Medial compressible forefoot sole elements reduce ankle inversion in lateral SSC jumps.

    PubMed

    Fleischmann, Jana; Mornieux, Guillaume; Gehring, Dominic; Gollhofer, Albert

    2013-06-01

    Sideward movements are associated with high incidences of lateral ankle sprains. Special shoe constructions might be able to reduce these injuries during lateral movements. The purpose of this study was to investigate whether medial compressible forefoot sole elements can reduce ankle inversion in a reactive lateral movement, and to evaluate those elements' influence on neuromuscular and mechanical adjustments in lower extremities. Foot placement and frontal plane ankle joint kinematics and kinetics were analyzed by 3-dimensional motion analysis. Electromyographic data of triceps surae, peroneus longus, and tibialis anterior were collected. This modified shoe reduced ankle inversion in comparison with a shoe with a standard sole construction. No differences in ankle inversion moments were found. With the modified shoe, foot placement occurred more internally rotated, and muscle activity of the lateral shank muscles was reduced. Hence, lateral ankle joint stability during reactive sideward movements can be improved by these compressible elements, and therefore lower lateral shank muscle activity is required. As those elements limit inversion, the strategy to control inversion angles via a high external foot rotation does not need to be used.

  15. Haemophilia Joint Health Score in healthy adults playing sports.

    PubMed

    Sluiter, D; Foppen, W; de Kleijn, P; Fischer, K

    2014-03-01

    To evaluate outcome of prophylactic clotting factor replacement in children with haemophilia, the Haemophilia Joint Health Score (HJHS) was developed aiming at scoring early joint changes in children aged 4-18. The HJHS has been used for adults on long-term prophylaxis but interpretation of small changes remains difficult. Some changes in these patients may be due to sports-related injuries. Evaluation of HJHS score in healthy adults playing sports could improve the interpretation of this score in haemophilic patients. The aim of this study was to evaluate the HJHS scores in a cohort of young, healthy men participating in sports. Concomitant with a project collecting MRI images of ankles and knees in normal young adults, HJHS scores were assessed in 30 healthy men aged 18-26, participating in sports one to three times per week. One physiotherapist assessed their clinical function using the HJHS 2.1. History of joint injuries was documented. MRI images were scored by a single radiologist, using the International Prophylaxis Study Group additive MRI score. Median age of the study group was 24.3 years (range 19.0-26.4) and median frequency of sports activities was three times per week (range 1-4). Six joints (five knees, one ankle) had a history of sports-related injury. The median overall HJHS score was 0 out of 124 (range 0-3), with 60% of subjects showing no abnormalities on HJHS. All joints were normal on MRI. These results suggest that frequent sports participation and related injuries are not related with abnormalities in HJHS scores.

  16. Power Doppler ultrasonographic assessment of the ankle in patients with inflammatory rheumatic diseases.

    PubMed

    Suzuki, Takeshi

    2014-11-18

    Ankle involvement is frequent in patients with inflammatory rheumatic diseases, but accurate evaluation by physical examination is often difficult because of the complex anatomical structures of the ankle. Over the last decade, ultrasound (US) has become a practical imaging tool for the assessment of articular and periarticular pathologies, including joint synovitis, tenosynovitis, and enthesitis in rheumatic diseases. Progress in power Doppler (PD) technology has enabled evaluation of the strength of ongoing inflammation. PDUS is very useful for identifying the location and kind of pathologies in rheumatic ankles as well as for distinguishing between inflammatory processes and degenerative changes or between active inflammation and residual damage. The aim of this paper is to illustrate the US assessment of ankle lesions in patients with inflammatory rheumatic diseases, including rheumatoid arthritis, spondyloarthritis, and systemic lupus erythematosus, focusing on the utility of PDUS.

  17. Proximal tibiofibular joint: Rendezvous with a forgotten articulation

    PubMed Central

    Sarma, Amitav; Borgohain, Bhaskar; Saikia, Bishwajeet

    2015-01-01

    The proximal tibiofibular joint (PTFJ) is a plane type synovial joint. The primary function of the PTFJ is dissipation of torsional stresses applied at the ankle and the lateral tibial bending moments besides a very significant tensile, rather than compressive weight bearing. Though rare, early diagnosis and treatment of the PTFJ dislocation are essential to prevent chronic joint instability and extensive surgical intervention to restore normal PTFJ biomechanics, ankle and knee function, especially in athletes prone to such injuries. PTFJ dislocations often remain undiagnosed in polytrauma scenario with ipsilateral tibial fracture due to the absence of specific signs and symptoms of PTFJ injury. Standard orthopedic textbooks generally describe no specific tests or radiological signs for assessment of the integrity of this joint. The aim of this paper was to review the relevant clinical anatomy, biomechanics and traumatic pathology of PTFJ with its effect on the knee emphasizing the importance of early diagnosis through a high index of suspicion. Dislocation of the joint may have serious implications for the knee joint stability since fibular collateral ligament and posterolateral ligament complex is attached to the upper end of the fibula. Any high energy knee injury with peroneal nerve palsy should immediately raise the suspicion of PTFJ dislocation especially if the mechanism of injury involved knee twisting in flexion beyond 80° and in such cases a comparative radiograph of the contralateral side should be performed. Wider clinical awareness can avoid both embarrassingly extensive surgeries due to diagnostic delays or unnecessary overtreatment due to misinformation on the part of the treating surgeon. PMID:26538753

  18. Comparison of ultrasound and magnetic resonance imaging for diagnosis and follow-up of joint lesions in patients with haemophilia.

    PubMed

    Sierra Aisa, C; Lucía Cuesta, J F; Rubio Martínez, A; Fernández Mosteirín, N; Iborra Muñoz, A; Abío Calvete, M; Guillén Gómez, M; Moretó Quintana, A; Rubio Félix, D

    2014-01-01

    Haematomas and recurrent haemarthroses are a common problem in haemophilia patients from early age. Early diagnosis is critical in preventing haemophilic arthritis, and recent years have seen excellent advances in musculoskeletal ultrasound as a diagnostic tool in soft tissue lesions. In this study, we compared the results of ultrasound imaging for the diagnosis of musculoskeletal injuries in haemophilia patients with scores obtained using magnetic resonance (MRI) scans. A total of 61 haemophilia patients aged 4-82 years were included in this study. Both knees and ankles of each patient were assessed using the Gilbert (clinical assessment) and Pettersson scores (X-ray assessment). Patients with severe haemophilia (n = 30) were examined using ultrasound and MRI (Denver scoring system). Results obtained with ultrasound and MRI in severe patients were correlated using the Pearson test. In patients with severe haemophilia, normal joints were similarly assessed with MRI and ultrasound (κ = 1.000). By component of joint assessment, haemarthrosis was similarly diagnosed with both techniques in all joints (κ = 1.000). A good positive correlation was found between these techniques in detecting and locating synovial hyperplasia (κ = 0.839-1.000, knees and ankles respectively), and erosion of margins (κ = 0.850-1.000). The presence of bone cysts or cartilage loss was better detected with MRI (κ = 0.643-0.552 for knees and ankles, and κ = 0.643-0.462 respectively). Ultrasound is useful in detecting joint bleeds, synovial hyperplasia and joint erosions, with results comparable to those of MRI. A quick and affordable technique, ultrasound imaging may be useful for monitoring joint bleeds and structure normalization and maintenance in routine practice.

  19. The origin of the ankle

    NASA Astrophysics Data System (ADS)

    Codino, Antonio; Plouin, Francois

    2007-03-01

    The differential intensity of cosmic radiation shows a sequence of depressions referred to as knees in a large energy band above 1015eV. The global depression entailed in the complete spectrum with respect to the extrapolated intensity based on low energy data, amounts to a maximum factor of 8, occurring at 5×10eV, where flux measurements exhibit a relative minimum, referred to as the ankle. It is demonstrated by a full simulation of cosmic ray trajectories in the Galaxy that the intensity minimum around the ankle energy is primarily due to the nuclear interactions of the cosmic ions with the interstellar matter and to the galactic magnetic field. Ankles signal the onset energies of the rectilinear propagation in the Milky Way at Earth, being for example, 4×10eV for helium and 6×10eV for iron. The ankle, in spite of its notable importance at Earth, is a local perturbation of the universal spectrum which, between the knee and the ankle, decreases by a round factor 109 regaining its unperturbed status above 1019eV.

  20. Posterior Ankle Structure Injury During Total Ankle Replacement.

    PubMed

    Reb, Christopher W; McAlister, Jeffrey E; Hyer, Christopher F; Berlet, Gregory C

    2016-01-01

    Total ankle replacement studies have focused on reporting complications that are directly observed clinically or radiographically, including wound problems, technical errors, implant loosening, subsidence, infection, bone fractures, and heterotopic ossification. However, patients can still experience unresolved pain even when these problems have been ruled out. We initiated a study to more clearly define the relative risk of injury to the anatomic structures in the posterior ankle during total ankle replacement using a third-generation implant system. Ten fresh-frozen adult cadaveric below-the-knee specimens were positioned in the intraoperative positioning frame of an approved total ankle replacement system and adjusted to achieve proper foot alignment using fluoroscopic imaging. The relationship between the tibial cutting guide pins and the posterior neurovascular and tendon structures was measured using digital calipers. High rates of posterior structural injury were found. Nearly all proximal-medial pins encountered a posteromedial neurovascular structure, most commonly the tibial nerve. The distal-medial pins mainly encountered posteromedial tendinous structures, in particular, the flexor digitorum longus tendon. The proximal lateral pins were highly likely to encounter the Achilles tendon and the sural nerve. Our results support our hypothesis that the tibial neurovascular structures are at the greatest risk when preparing for and completing the bony resection, particularly with the medial and proximal cuts. Posterior ankle soft tissue structure injuries can occur during implantation but currently with unknown frequency and undetermined significance. Further study of posterior structural injuries could result in a more informed approach to post-total ankle replacement complications and management. PMID:27291681

  1. Posterior Ankle Structure Injury During Total Ankle Replacement.

    PubMed

    Reb, Christopher W; McAlister, Jeffrey E; Hyer, Christopher F; Berlet, Gregory C

    2016-01-01

    Total ankle replacement studies have focused on reporting complications that are directly observed clinically or radiographically, including wound problems, technical errors, implant loosening, subsidence, infection, bone fractures, and heterotopic ossification. However, patients can still experience unresolved pain even when these problems have been ruled out. We initiated a study to more clearly define the relative risk of injury to the anatomic structures in the posterior ankle during total ankle replacement using a third-generation implant system. Ten fresh-frozen adult cadaveric below-the-knee specimens were positioned in the intraoperative positioning frame of an approved total ankle replacement system and adjusted to achieve proper foot alignment using fluoroscopic imaging. The relationship between the tibial cutting guide pins and the posterior neurovascular and tendon structures was measured using digital calipers. High rates of posterior structural injury were found. Nearly all proximal-medial pins encountered a posteromedial neurovascular structure, most commonly the tibial nerve. The distal-medial pins mainly encountered posteromedial tendinous structures, in particular, the flexor digitorum longus tendon. The proximal lateral pins were highly likely to encounter the Achilles tendon and the sural nerve. Our results support our hypothesis that the tibial neurovascular structures are at the greatest risk when preparing for and completing the bony resection, particularly with the medial and proximal cuts. Posterior ankle soft tissue structure injuries can occur during implantation but currently with unknown frequency and undetermined significance. Further study of posterior structural injuries could result in a more informed approach to post-total ankle replacement complications and management.

  2. Effects of ankle eversion taping using kinesiology tape in a patient with ankle inversion sprain.

    PubMed

    Lee, Sun-Min; Lee, Jung-Hoon

    2016-01-01

    [Purpose] The aim of this study was to report the effects of ankle eversion taping using kinesiology tape on ankle inversion sprain. [Subject] The subject was a 21-year-old woman with Grade 2 ankle inversion sprain. [Methods] Ankle eversion taping was applied to the sprained left ankle using kinesiology tape for 4 weeks (average, 15 h/day). [Results] Ankle instability and pain were reduced, and functional dynamic balance was improved after ankle eversion taping for 4 weeks. The Cumberland Ankle Instability Tool score and reach distances in the Y-Balance and lunge tests were increased. [Conclusion] Repeated ankle eversion taping may be an effective treatment intervention for ankle inversion sprain. PMID:27064668

  3. Effects of ankle eversion taping using kinesiology tape in a patient with ankle inversion sprain

    PubMed Central

    Lee, Sun-Min; Lee, Jung-Hoon

    2016-01-01

    [Purpose] The aim of this study was to report the effects of ankle eversion taping using kinesiology tape on ankle inversion sprain. [Subject] The subject was a 21-year-old woman with Grade 2 ankle inversion sprain. [Methods] Ankle eversion taping was applied to the sprained left ankle using kinesiology tape for 4 weeks (average, 15 h/day). [Results] Ankle instability and pain were reduced, and functional dynamic balance was improved after ankle eversion taping for 4 weeks. The Cumberland Ankle Instability Tool score and reach distances in the Y-Balance and lunge tests were increased. [Conclusion] Repeated ankle eversion taping may be an effective treatment intervention for ankle inversion sprain. PMID:27064668

  4. Effects of ankle eversion taping using kinesiology tape in a patient with ankle inversion sprain.

    PubMed

    Lee, Sun-Min; Lee, Jung-Hoon

    2016-01-01

    [Purpose] The aim of this study was to report the effects of ankle eversion taping using kinesiology tape on ankle inversion sprain. [Subject] The subject was a 21-year-old woman with Grade 2 ankle inversion sprain. [Methods] Ankle eversion taping was applied to the sprained left ankle using kinesiology tape for 4 weeks (average, 15 h/day). [Results] Ankle instability and pain were reduced, and functional dynamic balance was improved after ankle eversion taping for 4 weeks. The Cumberland Ankle Instability Tool score and reach distances in the Y-Balance and lunge tests were increased. [Conclusion] Repeated ankle eversion taping may be an effective treatment intervention for ankle inversion sprain.

  5. A multisegment computer simulation of normal human gait.

    PubMed

    Gilchrist, L A; Winter, D A

    1997-12-01

    The goal of this project was to develop a computer simulation of normal human walking that would use as driving moments resultant joint moments from a gait analysis. The system description, initial conditions and driving moments were taken from an inverse dynamics analysis of a normal walking trial. A nine-segment three-dimensional (3-D) model, including a two-part foot, was used. Torsional, linear springs and dampers were used at the hip joints to keep the trunk vertical and at the knee and ankle joints to prevent nonphysiological motion. Dampers at other joints were required to ensure a smooth and realistic motion. The simulated human successfully completed one step (550 ms), including both single and double support phases. The model proved to be sensitive to changes in the spring stiffness values of the trunk controllers. Similar sensitivity was found with the springs used to prevent hyperextension of the knee at heel contact and of the metatarsal-phalangeal joint at push-off. In general, there was much less sensitivity to the damping coefficients. This simulation improves on previous efforts because it incorporates some features necessary in simulations designed to answer clinical science questions. Other control algorithms are required, however, to ensure that the model can be realistically adapted to different subjects.

  6. Mechanical and energetic consequences of reduced ankle plantar-flexion in human walking.

    PubMed

    Huang, Tzu-wei P; Shorter, Kenneth A; Adamczyk, Peter G; Kuo, Arthur D

    2015-11-01

    The human ankle produces a large burst of 'push-off' mechanical power late in the stance phase of walking, reduction of which leads to considerably poorer energy economy. It is, however, uncertain whether the energetic penalty results from poorer efficiency when the other leg joints substitute for the ankle's push-off work, or from a higher overall demand for work due to some fundamental feature of push-off. Here, we show that greater metabolic energy expenditure is indeed explained by a greater demand for work. This is predicted by a simple model of walking on pendulum-like legs, because proper push-off reduces collision losses from the leading leg. We tested this by experimentally restricting ankle push-off bilaterally in healthy adults (N=8) walking on a treadmill at 1.4 m s(-1), using ankle-foot orthoses with steel cables limiting motion. These produced up to ∼50% reduction in ankle push-off power and work, resulting in up to ∼50% greater net metabolic power expenditure to walk at the same speed. For each 1 J reduction in ankle work, we observed 0.6 J more dissipative collision work by the other leg, 1.3 J more positive work from the leg joints overall, and 3.94 J more metabolic energy expended. Loss of ankle push-off required more positive work elsewhere to maintain walking speed; this additional work was performed by the knee, apparently at reasonably high efficiency. Ankle push-off may contribute to walking economy by reducing dissipative collision losses and thus overall work demand.

  7. Anterior Approach Total Ankle Arthroplasty: Superficial Peroneal Nerve Branches at Risk.

    PubMed

    McAlister, Jeffrey E; DeMill, Shyler L; Hyer, Christopher F; Berlet, Gregory C

    2016-01-01

    In ankle arthroplasty, little attention has been given to intraoperative nerve injury and its postoperative sequelae. The aim of the present anatomic study was to determine the relationship of the superficial peroneal nerve to the standard anterior approach for total ankle arthroplasty. The superficial peroneal nerve was dissected in 10 below-the-knee cadaver specimens. The medial and intermediate dorsal cutaneous branches were identified. A needle was placed at the ankle joint. The following measurements were recorded: bifurcation into the medial and intermediate dorsal cutaneous branches, reference needle to the branches of the medial and intermediate superficial peroneal nerve, and the crossing branches of the medial dorsal cutaneous nerve. Two specimens (20%) had a medial dorsal cutaneous branch cross from medially to laterally. Eight specimens (80%) had a crossing branch of the medial dorsal cutaneous branch within 5 cm of the incision. No intermediate dorsal cutaneous branches were within the incision. The results from the present cadaver study suggest that during an anterior ankle approach, aberrant branches of the superficial peroneal nerve could require transection in 20% of patients at the joint level and ≤80% of patients with distal extension >35 mm from the ankle joint. The risk of injury to branches of the superficial peroneal nerve is substantial. The risk of nerve injury can be decreased with meticulous operative technique, smaller incisions, and the avoidance of aggressive retraction.

  8. Subperiosteal Hematoma of the Ankle

    PubMed Central

    Hui, S H; Lui, T H

    2016-01-01

    Introduction: Periosteal reaction has a long list of differential diagnoses ranging from trauma, infection, metabolic disease to malignancy. The morphology of periosteal reaction shown in imaging studies helps to narrow down the list of differential diagnoses. Case report: A 25 year old gentleman had an inversion injury to his left ankle. He complained of lateral ankle and posterior heel pain and swelling after the injury. Radiograph of his left ankle revealed solid, smooth periosteal reaction at posterior aspect of left distal tibia. MRI showed periosteal reaction at the corresponding site, which was better demonstrated in CT scan. Follow up MRI and CT showed maturation of the new bone formation at the site of periosteal reaction. Findings were compatible with subperiosteal hematoma formation from injury, which ossified with time. Conclusion: Smooth, thick periosteal reaction favours benign process, while interrupted pattern is an alarming feature for more aggressive causes.

  9. Lateral ankle sprains and instability problems.

    PubMed

    Liu, S H; Jason, W J

    1994-10-01

    The lateral ankle complex is the most frequently injured single structure in athletes, consisting of 38% to 45% of all injuries. One-sixth of all sports injury loss time is from ankle sprains. In North America, ankle inversion sprains are considered "de rigeur" for basketball participation.

  10. Forms of forward quadrupedal locomotion. I. A comparison of posture, hindlimb kinematics, and motor patterns for normal and crouched walking.

    PubMed

    Trank, T V; Chen, C; Smith, J L

    1996-10-01

    1. Posture, hindlimb kinematics, and activity patterns of selected hindlimb muscles were compared for normal and crouched treadmill walking (0.5-0.6 m/s) for eight cats. To elicit crouched walking in which the trunk and head were lowered, cats were encouraged to walk under a light-weight Plexiglas ceiling suspended 17-20 cm above the treadmill belt. Kinematic data were obtained from high-speed ciné film, and electromyograms (EMGs)-synchronized with the kinematic records-were taken from 11 hindlimb muscles. 2. The postures for the two forms of walking were distinctly different. During crouched walking, each cat lowered its entire body keeping its trunk horizontal to the treadmill belt. Also the head was lowered, with the top of the head in line with the dorsal surface of the trunk. Hip height, used as a measure for hindlimb crouch, was reduced by 30%, from an average height of 23 cm to an average height of 16 cm above the belt during the entire step cycle. 3. Average cycle periods (766 +/- 30 ms, mean +/- SD) and percentage of time devoted to swing (30%) and stance (70%) were similar for normal and crouched walking. The profiles of the hindlimb kinematics were also similar for the hip, knee, ankle, and metatarsophalangeal (MTP) joints during the step cycle, but the timing of some of the motion reversal, as well as the ranges of motion during various phases, were different at some joints for the two forms of walking. 4. During the swing phase, the transition between the flexion and extension (F-E1 reversal) occurred later in the normalized swing phase at the hip, knee, and ankle joints, and the range of flexion was increased at each joint. With greater flexion at these joints, the anatomic axis of the hindlimb (measured from hip joint to toe) was decreased and the hind paw advanced in the narrow space between the abdomen and treadmill belt. At contact, the position of the paw was less anterior to the perpendicular reference line (hip joint marker to belt) and all

  11. Reflex ankle stiffness is inversely correlated with natural body sway.

    PubMed

    Julien, Brianna L; Bendrups, Andrew P

    2016-02-01

    We aimed to determine whether effective ankle stiffness (EAS), measured during slow unperceived perturbations of stance, is related to natural anterior-posterior body sway. Because the perturbations are not perceived, any neural component of the response to perturbation is assumed to be "reflex", in the broad sense of an involuntary response to a stimulus. Subjects stood on a force platform for three 10-min trials. EAS was obtained from the average slope (Δτ/Δα) of the relation between ankle torque (τ) and ankle angle (α), recorded during repeated perturbations delivered at the waist by a weak spring. EAS was normalised using the subject's "load stiffness" (LS), calculated from mass (m) and height (h) above the ankle joint (m·g·h). Sway was obtained from fluctuations in ankle angle prior to perturbation. Variation in EAS and sway between subjects provided spread of data for correlation. There were no significant changes in EAS or sway across trials. All subjects had higher EAS than LS and mean EAS (1124 N m/rad) was significantly greater (p<0.01) than mean LS (531 N m/rad). There was a strong significant inverse correlation between mean sway and mean normalised EAS (r=-0.68, p=0.03). We conclude that the body, in response to slow unperceived perturbations, simulates an inverted pendulum with a stiffness of about twice LS and that EAS is largely generated by neural modulation of postural muscles. The inverse correlation between EAS and body sway suggests that the reflex mechanisms responding to perturbation also influence the extent of natural sway. PMID:27004645

  12. Variable Joint Elasticities in Running

    NASA Astrophysics Data System (ADS)

    Peter, Stephan; Grimmer, Sten; Lipfert, Susanne W.; Seyfarth, Andre

    In this paper we investigate how spring-like leg behavior in human running is represented at joint level. We assume linear torsion springs in the joints and between the knee and the ankle joint. Using experimental data of the leg dynamics we compute how the spring parameters (stiffness and rest angles) change during gait cycle. We found that during contact the joints reveal elasticity with strongly changing parameters and compare the changes of different parameters for different spring arrangements. The results may help to design and improve biologically inspired spring mechanisms with adjustable parameters.

  13. Running with a powered knee and ankle prosthesis.

    PubMed

    Shultz, Amanda H; Lawson, Brian E; Goldfarb, Michael

    2015-05-01

    This paper presents a running control architecture for a powered knee and ankle prosthesis that enables a transfemoral amputee to run with a biomechanically appropriate running gait and to intentionally transition between a walking and running gait. The control architecture consists firstly of a coordination level controller, which provides gait biomechanics representative of healthy running, and secondly of a gait selection controller that enables the user to intentionally transition between a running and walking gait. The running control architecture was implemented on a transfemoral prosthesis with powered knee and ankle joints, and the efficacy of the controller was assessed in a series of running trials with a transfemoral amputee subject. Specifically, treadmill trials were conducted to assess the extent to which the coordination controller provided a biomechanically appropriate running gait. Separate trials were conducted to assess the ability of the user to consistently and reliably transition between walking and running gaits.

  14. Use of infrared thermography for the diagnosis and grading of sprained ankle injuries

    NASA Astrophysics Data System (ADS)

    Oliveira, João; Vardasca, Ricardo; Pimenta, Madalena; Gabriel, Joaquim; Torres, João

    2016-05-01

    Ankle joint sprains are a common medical condition estimated to be responsible for 15-25% of all musculoskeletal injuries worldwide. The pathophysiology of the lesion can represent considerable time lost to injury, as well as long-term disability in up to 60% of patients. A percentage between 10% and 20% may complicate with chronic instability of the ankle joint and disability in walking, contributing to morbidity and poor life quality. Ankle sprains can be classified as grade I, II, or III, based on the extent of damage and number of ligaments affected. The diagnostic grading is important for setting further treatment and rehabilitation, since more severe injuries carries risk of recurrence, added morbidity and decrease in life quality. The aim of this work was to evaluate the adequacy of infrared thermography as a potential complimentary diagnostic tool of the distinct lesions grades. Evaluation of different thermographic values of the ankle region (in both affected and non-affected foot) was conducted for this purpose. The principal results to be highlighted are that some of the regions, namely anterior view for non defined time after injury analysis, and anterior, frontal, posterior and anterior talofibular ligament regions and proximal calcaneofibular ligament regions in acute lesions (herein defined as less than 6 h post-traumatic event) presented consistent profiles of variation. The analyses were performed considering affected and non-affected ankles results on plotted graphics representing termographic evaluation and grading of these lesions performed using ultrasound by experimented medical radiologists. An increase in temperature values was observed when progressing from mild to severe ankle sprain injuries, with these regions presenting lower values for the affected ankle when compared to the non-affected ankle in all the analysis performed. The remaining analysed regions did not present the same variations. Statistical analysis using Kruskal

  15. Leg joint function during walking acceleration and deceleration.

    PubMed

    Qiao, Mu; Jindrich, Devin L

    2016-01-01

    Although constant-average-velocity walking has been extensively studied, less is known about walking maneuvers that change speed. We investigated the function of individual leg joints when humans walked at a constant speed, accelerated or decelerated. We hypothesized that leg joints make different functional contributions to maneuvers. Specifically, we hypothesized that the hip generates positive mechanical work (acting like a "motor"), the knee generates little mechanical work (acting like a "strut"), and the ankle absorbs energy during the first half of stance and generates energy during the second half (consistent with "spring"-like function). We recorded full body kinematics and kinetics, used inverse dynamics to estimate net joint moments, and decomposed joint function into strut-, motor-, damper-, and spring-like components using indices based on net joint work. Although overall leg mechanics were primarily strut-like, individual joints did not act as struts during stance. The hip functioned as a power generating "motor," and ankle function was consistent with spring-like behavior. Even though net knee work was small, the knee did not behave solely as a strut but also showed motor-, and damper-like function. Acceleration involved increased motor-like function of the hip and ankle. Deceleration involved decreased hip motor-like function and ankle spring-like function and increased damping at the knee and ankle. Changes to joint mechanical work were primarily due to changes in joint angular displacements and not net moments. Overall, joints maintain different functional roles during unsteady locomotion.

  16. A Comparative Analysis of Speed Profile Models for Ankle Pointing Movements: Evidence that Lower and Upper Extremity Discrete Movements are Controlled by a Single Invariant Strategy

    PubMed Central

    Michmizos, Konstantinos P.; Vaisman, Lev; Krebs, Hermano Igo

    2014-01-01

    Little is known about whether our knowledge of how the central nervous system controls the upper extremities (UE), can generalize, and to what extent to the lower limbs. Our continuous efforts to design the ideal adaptive robotic therapy for the lower limbs of stroke patients and children with cerebral palsy highlighted the importance of analyzing and modeling the kinematics of the lower limbs, in general, and those of the ankle joints, in particular. We recruited 15 young healthy adults that performed in total 1,386 visually evoked, visually guided, and target-directed discrete pointing movements with their ankle in dorsal–plantar and inversion–eversion directions. Using a non-linear, least-squares error-minimization procedure, we estimated the parameters for 19 models, which were initially designed to capture the dynamics of upper limb movements of various complexity. We validated our models based on their ability to reconstruct the experimental data. Our results suggest a remarkable similarity between the top-performing models that described the speed profiles of ankle pointing movements and the ones previously found for the UE both during arm reaching and wrist pointing movements. Among the top performers were the support-bounded lognormal and the beta models that have a neurophysiological basis and have been successfully used in upper extremity studies with normal subjects and patients. Our findings suggest that the same model can be applied to different “human” hardware, perhaps revealing a key invariant in human motor control. These findings have a great potential to enhance our rehabilitation efforts in any population with lower extremity deficits by, for example, assessing the level of motor impairment and improvement as well as informing the design of control algorithms for therapeutic ankle robots. PMID:25505881

  17. A Comparative Analysis of Speed Profile Models for Ankle Pointing Movements: Evidence that Lower and Upper Extremity Discrete Movements are Controlled by a Single Invariant Strategy.

    PubMed

    Michmizos, Konstantinos P; Vaisman, Lev; Krebs, Hermano Igo

    2014-01-01

    Little is known about whether our knowledge of how the central nervous system controls the upper extremities (UE), can generalize, and to what extent to the lower limbs. Our continuous efforts to design the ideal adaptive robotic therapy for the lower limbs of stroke patients and children with cerebral palsy highlighted the importance of analyzing and modeling the kinematics of the lower limbs, in general, and those of the ankle joints, in particular. We recruited 15 young healthy adults that performed in total 1,386 visually evoked, visually guided, and target-directed discrete pointing movements with their ankle in dorsal-plantar and inversion-eversion directions. Using a non-linear, least-squares error-minimization procedure, we estimated the parameters for 19 models, which were initially designed to capture the dynamics of upper limb movements of various complexity. We validated our models based on their ability to reconstruct the experimental data. Our results suggest a remarkable similarity between the top-performing models that described the speed profiles of ankle pointing movements and the ones previously found for the UE both during arm reaching and wrist pointing movements. Among the top performers were the support-bounded lognormal and the beta models that have a neurophysiological basis and have been successfully used in upper extremity studies with normal subjects and patients. Our findings suggest that the same model can be applied to different "human" hardware, perhaps revealing a key invariant in human motor control. These findings have a great potential to enhance our rehabilitation efforts in any population with lower extremity deficits by, for example, assessing the level of motor impairment and improvement as well as informing the design of control algorithms for therapeutic ankle robots.

  18. A Comparative Analysis of Speed Profile Models for Ankle Pointing Movements: Evidence that Lower and Upper Extremity Discrete Movements are Controlled by a Single Invariant Strategy.

    PubMed

    Michmizos, Konstantinos P; Vaisman, Lev; Krebs, Hermano Igo

    2014-01-01

    Little is known about whether our knowledge of how the central nervous system controls the upper extremities (UE), can generalize, and to what extent to the lower limbs. Our continuous efforts to design the ideal adaptive robotic therapy for the lower limbs of stroke patients and children with cerebral palsy highlighted the importance of analyzing and modeling the kinematics of the lower limbs, in general, and those of the ankle joints, in particular. We recruited 15 young healthy adults that performed in total 1,386 visually evoked, visually guided, and target-directed discrete pointing movements with their ankle in dorsal-plantar and inversion-eversion directions. Using a non-linear, least-squares error-minimization procedure, we estimated the parameters for 19 models, which were initially designed to capture the dynamics of upper limb movements of various complexity. We validated our models based on their ability to reconstruct the experimental data. Our results suggest a remarkable similarity between the top-performing models that described the speed profiles of ankle pointing movements and the ones previously found for the UE both during arm reaching and wrist pointing movements. Among the top performers were the support-bounded lognormal and the beta models that have a neurophysiological basis and have been successfully used in upper extremity studies with normal subjects and patients. Our findings suggest that the same model can be applied to different "human" hardware, perhaps revealing a key invariant in human motor control. These findings have a great potential to enhance our rehabilitation efforts in any population with lower extremity deficits by, for example, assessing the level of motor impairment and improvement as well as informing the design of control algorithms for therapeutic ankle robots. PMID:25505881

  19. Anatomy of the ankle ligaments: a pictorial essay.

    PubMed

    Golanó, Pau; Vega, Jordi; de Leeuw, Peter A J; Malagelada, Francesc; Manzanares, M Cristina; Götzens, Víctor; van Dijk, C Niek

    2016-04-01

    Understanding the anatomy of the ankle ligaments is important for correct diagnosis and treatment. Ankle ligament injury is the most frequent cause of acute ankle pain. Chronic ankle pain often finds its cause in laxity of one of the ankle ligaments. In this pictorial essay, the ligaments around the ankle are grouped, depending on their anatomic orientation, and each of the ankle ligaments is discussed in detail.

  20. A Study of the Effect of Adhesive and Matrix Stiffnesses on the Axial, Normal, and Shear Stress Distributions of a Boron-epoxy Reinforced Composite Joint. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Howell, W. E.

    1974-01-01

    The mechanical properties of a symmetrical, eight-step, titanium-boron-epoxy joint are discussed. A study of the effect of adhesive and matrix stiffnesses on the axial, normal, and shear stress distributions was made using the finite element method. The NASA Structural Analysis Program (NASTRAN) was used for the analysis. The elastic modulus of the adhesive was varied from 345 MPa to 3100 MPa with the nominal value of 1030 MPa as a standard. The nominal values were used to analyze the stability of the joint. The elastic moduli were varied to determine their effect on the stresses in the joint.

  1. An induced acceleration index for examining joint couplings.

    PubMed

    Challis, John H

    2011-08-11

    A muscle produces moments at the joints it crosses, but these moments can also cause accelerations at joints not crossed by the muscle. This phenomenon, the acceleration of a joint caused by a muscle not crossing the joint, is referred to as induced acceleration. For a system of rigid bodies this study examines how system configuration, and segmental inertial properties dictate the potential of one joint to cause the acceleration of other joints in the system. From the equations of motion for a series of rigid bodies, an induced acceleration index (IAI) was developed. The IAI permits quantification of the relative potential of moments produced at joints in the kinematic chain to accelerate other joints in the kinematic chain. The IAI is a function of system orientation, segment lengths, and inertial properties. The IAI was used to examine the roles of the ankle and hip joints in quiet standing. The ankle joint had over 12 times the ability to accelerate the hip joint, than the hip had to accelerate the ankle joint. These results in part explain the relative merits of the two strategies predominantly used to maintain upright stance: the ankle and hip strategies. This index permits an understanding of how the induced accelerations are dependent on system configuration and inertial properties. The IAI is also useful in situations where the inertial properties of the system under investigation changes, for example due to the fitting of a new prostheses to a trans-tibial amputee.

  2. Ankle inversion taping using kinesiology tape for treating medial ankle sprain in an amateur soccer player

    PubMed Central

    Lee, Sun-Min; Lee, Jung-Hoon

    2015-01-01

    [Purpose] The purpose of this study was to report the effects of ankle inversion taping using kinesiology tape in a patient with a medial ankle sprain. [Subject] A 28-year-old amateur soccer player suffered a Grade 2 medial ankle sprain during a match. [Methods] Ankle inversion taping was applied to the sprained ankle every day for 2 months. [Results] His symptoms were reduced after ankle inversion taping application for 2 months. The self-reported function score, the reach distances in the Star Excursion Balance Test, and the weight-bearing ankle dorsiflexion were increased. [Conclusion] This study showed that ankle inversion taping using kinesiology tape may be an effective therapy for a patient with a medial ankle sprain. PMID:26311991

  3. Ankle inversion taping using kinesiology tape for treating medial ankle sprain in an amateur soccer player.

    PubMed

    Lee, Sun-Min; Lee, Jung-Hoon

    2015-07-01

    [Purpose] The purpose of this study was to report the effects of ankle inversion taping using kinesiology tape in a patient with a medial ankle sprain. [Subject] A 28-year-old amateur soccer player suffered a Grade 2 medial ankle sprain during a match. [Methods] Ankle inversion taping was applied to the sprained ankle every day for 2 months. [Results] His symptoms were reduced after ankle inversion taping application for 2 months. The self-reported function score, the reach distances in the Star Excursion Balance Test, and the weight-bearing ankle dorsiflexion were increased. [Conclusion] This study showed that ankle inversion taping using kinesiology tape may be an effective therapy for a patient with a medial ankle sprain.

  4. Analysis of Ankle Kinetics during Walking in Individuals with Down Syndrome.

    ERIC Educational Resources Information Center

    Cioni, Matteo; Cocilovo, Anna; Rossi, Fabio; Paci, Domenico; Valle, Maria Stella

    2001-01-01

    The biomechanical characteristics of the ankle during gait of 17 participants with Down syndrome (ages 8-36) were investigated. Participants showed significant decreases of plantar-flexor moments and of A1 and A2 joint powers. Correlation between kinetic and temporal spatial parameters was markedly reduced or weak in comparison to 10 controls.…

  5. Comparison of Functional Ankle Motion Measures in Modern Dancers.

    PubMed

    Dickson, Danelle; Hollman-Gage, Kendra; Ojofeitimi, Sheyi; Bronner, Shaw

    2012-09-01

    Ankle injuries are the most common lower extremity injury in dance and sports, often resulting in limitation of dorsiflexion or plantar flexion. Accurate assessment of any limitation in range of motion is an important factor in implementing effective preventative and rehabilitative regimens. Ankle range of motion has traditionally been quantified with goniometers. However, standard goniometry may not be an adequate method of assessing plantar flexion range of motion in dancers. An alternative technique using inclinometers to quantify ankle plantar flexion has been reported, but reliability and inter-instrument correlations for this method are limited. The dorsiflexion lunge distance method has been used to assess ankle dorsiflexion. Although shown to be reliable, this method has not been objectively correlated. The purpose of this study was to determine the most clinically appropriate tool for assessing functional ankle dorsiflexion and plantar flexion in dancers. The aims were to: 1. determine reliability of the weightbearing ankle dorsiflexion lunge method using inclinometer, goniometer, and distance; 2. assess the reliability of inclinometer and goniometer measurements of non-weightbearing active plantar flexion; 3. conduct inter-method and experienced versus novice rater correlations; and 4. determine if a relationship exists between dorsiflexion distance (cm) and dorsiflexion inclinometer angle (degrees) measurements. Twenty-six modern dancers (age: 20.2 ± 1.8 years) participated in the study. Four raters measured weightbearing dorsiflexion in a lunge position using a goniometer, two inclinometer placements, and a distance measurement. They also measured active ankle plantar flexion using an inclinometer placed on the anterior talonavicular joint and a goniometer placed at the lateral ankle. Intra- and inter-rater reliability and inter-method correlations were calculated with Intraclass Correlation Coefficients (ICC) and standard error of measurement (SEM

  6. Minimally invasive soft tissue release of foot and ankle contracture secondary to stroke.

    PubMed

    Boffeli, Troy J; Collier, Rachel C

    2014-01-01

    Lower extremity contracture associated with stroke commonly results in a nonreducible, spastic equinovarus deformity of the foot and ankle. Rigid contracture deformity leads to gait instability, pain, bracing difficulties, and ulcerations. The classic surgical approach for stroke-related contracture of the foot and ankle has been combinations of tendon lengthening, tendon transfer, osteotomy, and joint fusion procedures. Recovery after traditional foot and ankle reconstructive surgery requires a period of non-weightbearing that is not typically practical for these patients. Little focus has been given in published studies on minimally invasive soft tissue release of contracture. We present the case of a 61-year-old female with an equinovarus foot contracture deformity secondary to stroke. The patient underwent Achilles tendon lengthening, posterior tibial tendon Z lengthening, and digital flexor tenotomy of each toe with immediate weightbearing in a walking boot, followed by transition to an ankle-foot orthosis. The surgical principles and technique tips are presented to demonstrate our minimally invasive approach to release of foot and ankle contracture secondary to stroke. The main goal of this approach is to improve foot and ankle alignment for ease of bracing, which, in turn, will improve gait, reduce the risk of falls, decrease pain, and avoid the development of pressure sores. PMID:23890795

  7. Operative exploration and reduction of syndesmosis in Weber type C ankle injury

    PubMed Central

    Yang, Yunfeng; Zhou, Jiaqian; Li, Bing; Zhao, Hongmou; Yu, Tao; Yu, Guangrong

    2013-01-01

    OBJECTIVE: To investigate the surgical methods in treating Weber type C ankle injury and estimate the necessity of syndesmosis operative exploration. METHODS: Forty three patients of Weber type C ankle injury were treated with open reduction and internal fixation from October 2004 to December 2009. Twenty nine patients were treated with routine procedure by open reduction and internal fixation, syndesmosis exploration and repair were performed in addition in the others. Thirty four patients were followed during an average time of 31.2 months (range 18 to 50 months), amomg them 22 patients were treated with routine procedures and 12 were treated with additional syndesmosis surgical exploration. RESULTS: All the fractures were reunited in an average time of 13.1 weeks (range 10 to 18 weeks) and full weight bearing began. The mean ankle and hindfoot scale of the American Orthopaedic Foot and Ankle Society (AOFAS) score was 79.86(range 65 to 98) in the routine procedures group and 86.67 (range 78 to 100) in the syndesmosis exploration group and Olerud-Molander score was 77.27 (range 55 to 100) and 86.67 (range 75 to 100) respectively. Statistically significant difference was found between the two groups (P<0.05). CONCLUSION: Syndesmosis surgical exploration is an essential treatment in some Weber type C ankle injuries, which make debridement and direct reduction of the syndesmosis possible, providing thus a more stabilized ankle joint. Level of Evidence III, Retrospective Comparative Study PMID:24453652

  8. A Solitary Fibrous Tumor (Cellular Form) of the Ankle.

    PubMed

    Lee, Jun Yong; Kim, Dong-Hwi; Seo, Kyung-Jin; Jung, Sung-No

    2016-01-01

    A solitary fibrous tumor (SFT) is a rare type of mesenchymal tumor composed of uniform spindle cells that is classically described as a patternless feature. SFT normally originates from the pleura, with an SFT originating from skin rarely reported. We report what we believe to be the first case of an SFT arising from the ankle. Our case was confirmed histopathologically with immunohistochemical staining. PMID:25979291

  9. Physical Validation of a Patient-Specific Contact Finite Element Model of the Ankle

    PubMed Central

    Anderson, Donald D.; Goldsworthy, Jane K.; Wendy, Li; Rudert, M. James; Tochigi, Yuki; Brown, Thomas D.

    2007-01-01

    A validation study was conducted to determine the extent to which computational ankle contact finite element (FE) results agreed with experimentally measured tibio-talar contact stress. Two cadaver ankles were loaded in separate test sessions, during which ankle contact stresses were measured with a high-resolution (Tekscan) pressure sensor. Corresponding contact FE analyses were subsequently performed for comparison. The agreement was good between FE-computed and experimentally measured mean (3.2% discrepancy for one ankle, 19.3% for the other) and maximum (1.5% and 6.2%) contact stress, as well as for contact area (1.7% and 14.9%). There was also excellent agreement between histograms of fractional areas of cartilage experiencing specific ranges of contact stress. Finally, point-by-point comparisons between the computed and measured contact stress distributions over the articular surface showed substantial agreement, with correlation coefficients of 90% for one ankle, and 86% for the other. In the past, general qualitative, but little direct quantitative agreement has been demonstrated with articular joint contact FE models. The methods used for this validation enable formal comparison of computational and experimental results, and open the way for objective statistical measures of regional correlation between FE-computed contact stress distributions from comparison articular joint surfaces (e.g., those from an intact versus those with residual intra-articular fracture incongruity). PMID:17433333

  10. Are joint torque models limited by an assumption of monoarticularity?

    PubMed

    Lewis, Martin G C; King, Mark A; Yeadon, Maurice R; Conceição, Filipe

    2012-11-01

    This study determines whether maximal voluntary ankle plantar flexor torque could be more accurately represented using a torque generator that is a function of both knee and ankle kinematics. Isovelocity and isometric ankle plantar flexor torques were measured on a single participant for knee joint angles of 111° to 169° (approximately full extension) using a Contrex MJ dynamometer. Maximal voluntary torque was represented by a 19-parameter two-joint function of ankle and knee joint angles and angular velocities with the parameters determined by minimizing a weighted root mean square difference between measured torques and the two-joint function. The weighted root mean square difference between the two-joint function and the measured torques was 10 N-m or 3% of maximum torque. The two-joint function was a more accurate representation of maximal voluntary ankle plantar flexor torques than an existing single-joint function where differences of 19% of maximum torque were found. It is concluded that when the knee is flexed by more than 40°, a two-joint representation is necessary.

  11. Mechanical and energetic consequences of reduced ankle plantar-flexion in human walking

    PubMed Central

    Huang, Tzu-wei P.; Shorter, Kenneth A.; Adamczyk, Peter G.; Kuo, Arthur D.

    2015-01-01

    ABSTRACT The human ankle produces a large burst of ‘push-off’ mechanical power late in the stance phase of walking, reduction of which leads to considerably poorer energy economy. It is, however, uncertain whether the energetic penalty results from poorer efficiency when the other leg joints substitute for the ankle's push-off work, or from a higher overall demand for work due to some fundamental feature of push-off. Here, we show that greater metabolic energy expenditure is indeed explained by a greater demand for work. This is predicted by a simple model of walking on pendulum-like legs, because proper push-off reduces collision losses from the leading leg. We tested this by experimentally restricting ankle push-off bilaterally in healthy adults (N=8) walking on a treadmill at 1.4 m s−1, using ankle–foot orthoses with steel cables limiting motion. These produced up to ∼50% reduction in ankle push-off power and work, resulting in up to ∼50% greater net metabolic power expenditure to walk at the same speed. For each 1 J reduction in ankle work, we observed 0.6 J more dissipative collision work by the other leg, 1.3 J more positive work from the leg joints overall, and 3.94 J more metabolic energy expended. Loss of ankle push-off required more positive work elsewhere to maintain walking speed; this additional work was performed by the knee, apparently at reasonably high efficiency. Ankle push-off may contribute to walking economy by reducing dissipative collision losses and thus overall work demand. PMID:26385330

  12. Modeling and analysis of passive dynamic bipedal walking with segmented feet and compliant joints

    NASA Astrophysics Data System (ADS)

    Huang, Yan; Wang, Qi-Ning; Gao, Yue; Xie, Guang-Ming

    2012-10-01

    Passive dynamic walking has been developed as a possible explanation for the efficiency of the human gait. This paper presents a passive dynamic walking model with segmented feet, which makes the bipedal walking gait more close to natural human-like gait. The proposed model extends the simplest walking model with the addition of flat feet and torsional spring based compliance on ankle joints and toe joints, to achieve stable walking on a slope driven by gravity. The push-off phase includes foot rotations around the toe joint and around the toe tip, which shows a great resemblance to human normal walking. This paper investigates the effects of the segmented foot structure on bipedal walking in simulations. The model achieves satisfactory walking results on even or uneven slopes.

  13. Ankle and knee kinetics between strike patterns at common training speeds in competitive male runners.

    PubMed

    Kuhman, Daniel; Melcher, Daniel; Paquette, Max R

    2016-01-01

    The purpose of this study was to investigate the interaction of foot strike and common speeds on sagittal plane ankle and knee joint kinetics in competitive rear foot strike (RFS) runners when running with a RFS pattern and an imposed forefoot strike (FFS) pattern. Sixteen competitive habitual male RFS runners ran at two different speeds (i.e. 8 and 6 min mile(-1)) using their habitual RFS and an imposed FFS pattern. A repeated measures analysis of variance was used to assess a potential interaction between strike pattern and speed for selected ground reaction force (GRF) variables and, sagittal plane ankle and knee kinematic and kinetic variables. No foot strike and speed interaction was observed for any of the kinetic variables. Habitual RFS yielded a greater loading rate of the vertical GRF, peak ankle dorsiflexor moment, peak knee extensor moment, peak knee eccentric extensor power, peak dorsiflexion and sagittal plane knee range of motion compared to imposed FFS. Imposed FFS yielded greater maximum vertical GRF, peak ankle plantarflexor moment, peak ankle eccentric plantarflexor power and sagittal plane ankle ROM compared to habitual RFS. Consistent with previous literature, imposed FFS in habitual RFS reduces eccentric knee extensor and ankle dorsiflexor involvement but produce greater eccentric ankle plantarflexor action compared to RFS. These acute differences between strike patterns were independent of running speeds equivalent to typical easy and hard training runs in competitive male runners. Current findings along with previous literature suggest differences in lower extremity kinetics between habitual RFS and imposed FFS running are consistent among a variety of runner populations.

  14. Ankle and knee kinetics between strike patterns at common training speeds in competitive male runners.

    PubMed

    Kuhman, Daniel; Melcher, Daniel; Paquette, Max R

    2016-01-01

    The purpose of this study was to investigate the interaction of foot strike and common speeds on sagittal plane ankle and knee joint kinetics in competitive rear foot strike (RFS) runners when running with a RFS pattern and an imposed forefoot strike (FFS) pattern. Sixteen competitive habitual male RFS runners ran at two different speeds (i.e. 8 and 6 min mile(-1)) using their habitual RFS and an imposed FFS pattern. A repeated measures analysis of variance was used to assess a potential interaction between strike pattern and speed for selected ground reaction force (GRF) variables and, sagittal plane ankle and knee kinematic and kinetic variables. No foot strike and speed interaction was observed for any of the kinetic variables. Habitual RFS yielded a greater loading rate of the vertical GRF, peak ankle dorsiflexor moment, peak knee extensor moment, peak knee eccentric extensor power, peak dorsiflexion and sagittal plane knee range of motion compared to imposed FFS. Imposed FFS yielded greater maximum vertical GRF, peak ankle plantarflexor moment, peak ankle eccentric plantarflexor power and sagittal plane ankle ROM compared to habitual RFS. Consistent with previous literature, imposed FFS in habitual RFS reduces eccentric knee extensor and ankle dorsiflexor involvement but produce greater eccentric ankle plantarflexor action compared to RFS. These acute differences between strike patterns were independent of running speeds equivalent to typical easy and hard training runs in competitive male runners. Current findings along with previous literature suggest differences in lower extremity kinetics between habitual RFS and imposed FFS running are consistent among a variety of runner populations. PMID:26371382

  15. A systematic review on ankle injury and ankle sprain in sports.

    PubMed

    Fong, Daniel Tik-Pui; Hong, Youlian; Chan, Lap-Ki; Yung, Patrick Shu-Hang; Chan, Kai-Ming

    2007-01-01

    This article systematically reviews epidemiological studies on sports injury from 1977 to 2005 in which ankle injury was included. A total of 227 studies reporting injury pattern in 70 sports from 38 countries were included. A total of 201,600 patients were included, with 32,509 ankle injuries. Ankle injury information was available from 14,098 patients, with 11 847 ankle sprains. Results show that the ankle was the most common injured body site in 24 of 70 included sports, especially in aeroball, wall climbing, indoor volleyball, mountaineering, netball and field events in track and field. Ankle sprain was the major ankle injury in 33 of 43 sports, especially in Australian football, field hockey, handball, orienteering, scooter and squash. In sports injuries throughout the countries studied, the ankle was the second most common injured body site after the knee, and ankle sprain was the most common type of ankle injury. The incidence of ankle injury and ankle sprain was high in court games and team sports, such as rugby, soccer, volleyball, handball and basketball. This systematic review provides a summary of the epidemiology of ankle injury in sports. PMID:17190537

  16. A systematic review on ankle injury and ankle sprain in sports.

    PubMed

    Fong, Daniel Tik-Pui; Hong, Youlian; Chan, Lap-Ki; Yung, Patrick Shu-Hang; Chan, Kai-Ming

    2007-01-01

    This article systematically reviews epidemiological studies on sports injury from 1977 to 2005 in which ankle injury was included. A total of 227 studies reporting injury pattern in 70 sports from 38 countries were included. A total of 201,600 patients were included, with 32,509 ankle injuries. Ankle injury information was available from 14,098 patients, with 11 847 ankle sprains. Results show that the ankle was the most common injured body site in 24 of 70 included sports, especially in aeroball, wall climbing, indoor volleyball, mountaineering, netball and field events in track and field. Ankle sprain was the major ankle injury in 33 of 43 sports, especially in Australian football, field hockey, handball, orienteering, scooter and squash. In sports injuries throughout the countries studied, the ankle was the second most common injured body site after the knee, and ankle sprain was the most common type of ankle injury. The incidence of ankle injury and ankle sprain was high in court games and team sports, such as rugby, soccer, volleyball, handball and basketball. This systematic review provides a summary of the epidemiology of ankle injury in sports.

  17. Contributions of knee swing initiation and ankle plantar flexion to the walking mechanics of amputees using a powered prosthesis.

    PubMed

    Ingraham, Kimberly A; Fey, Nicholas P; Simon, Ann M; Hargrove, Levi J

    2014-01-01

    Recently developed powered prostheses are capable of producing near-physiological joint torque at the knee and/or ankle joints. Based on previous studies of biological joint impedance and the mechanics of able-bodied gait, an impedance-based controller has been developed for a powered knee and ankle prosthesis that integrates knee swing initiation and powered plantar flexion in late stance with increasing ankle stiffness throughout stance. In this study, five prosthesis configuration conditions were tested to investigate the individual contributions of each sub-strategy to the overall walking mechanics of four unilateral transfemoral amputees as they completed a clinical 10-m walk test using a powered knee and ankle prosthesis. The baseline condition featured constant ankle stiffness and no swing initiation or powered plantar flexion. The four remaining conditions featured knee swing initiation alone (SI) or in combination with powered plantar flexion (SI+PF), increasing ankle stiffness (SI+IK), or both (SI+PF+IK). Self-selected walking speed did not significantly change between conditions, although subjects tended to walk the slowest in the baseline condition compared to conditions with swing initiation. The addition of powered plantar flexion resulted in significantly higher ankle power generation in late stance irrespective of ankle stiffness. The inclusion of swing initiation resulted in a significantly more flexed knee at toe off and a significantly higher average extensor knee torque following toe off. Identifying individual contributions of intrinsic control strategies to prosthesis biomechanics could help inform the refinement of impedance-based prosthesis controllers and simplify future designs of prostheses and lower-limb assistive devices alike.

  18. Ultrasound Assessment of Synovial Thickness of Some of the Metacarpophalangeal Joints of Hand in Rheumatoid Arthritis Patients and the Normal Population

    PubMed Central

    Hussain Manik, Zuhudha; George, John; Sockalingam, Sargunan

    2016-01-01

    Objective. To compare ultrasound synovial thickness of the 2nd, 3rd and 4th metacarpophalangeal joints (MCPJ) in a group of patients with proven rheumatoid arthritis (RA) and a control group of normal individuals. Materials and Methods. This is a cross-sectional study comprising 30 rheumatoid arthritis patients and 30 healthy individuals. Ultrasound scans were performed at the dorsal side of 2nd, 3rd, and 4th MCPJ of both hands in RA patients and the healthy individuals. Synovial thickness was measured according to quantitative method. The synovial thickness of RA patients and healthy individuals was compared and statistical cut-off was identified. Results. Maximum synovial thickness was most often detected at the radial side of the 2nd MCPJ and 3rd MCPJ and ulnar side of the 4th MCPJ of both hands which is significantly higher (p < 0.05) in RA patients compared to healthy individuals. With high specificity (96%) and sensitivity (90%) the optimum cut-off value to distinguish RA patients and healthy individuals' synovial thickness differs for the radial side of the 2nd and 3rd MCPJ and ulnar side of the 4th MCPJ. Conclusion. Patients with early RA appear to exhibit a characteristic pattern of synovitis which shows radial side predominance in the 2nd and 3rd MCPJ and ulnar side in the 4th MCPJ. PMID:27190682

  19. Experimental and computational analysis of composite ankle-foot orthosis.

    PubMed

    Zou, Dequan; He, Tao; Dailey, Michael; Smith, Kirk E; Silva, Matthew J; Sinacore, David R; Mueller, Michael J; Hastings, Mary K

    2014-01-01

    Carbon fiber (CF) ankle-foot orthoses (AFOs) can improve gait by increasing ankle plantar-flexor power and improving plantar-flexor ankle joint moment and energy efficiency compared with posterior leaf spring AFOs made of thermoplastic. However, fabricating a CF AFO to optimize the performance of the individual user may require multiple AFOs and expensive fabrication costs. Finite element analysis (FEA) models were developed to predict the mechanical behavior of AFOs in this study. Three AFOs, two made of CF composite material and one made of thermoplastic material, were fabricated and then mechanically tested to produce force-displacement data. The FEA models were validated by comparing model predictions with mechanical testing data performed under the same loading and boundary conditions. The actual mechanical testing demonstrated that CF performs better than thermoplastic. The simulation results showed that FEA models produced accurate predictions for both types of orthoses. The relative error of the energy return ratio predicted by the CF AFO FEA model developed in this study is less than 3%. We conclude that highly accurate FEA models will allow orthotists to improve CF AFO fabrication without wasting resources (time and money) on trial and error fabrications that are expensive and do not consistently improve AFO and user performance. PMID:25856154

  20. Ultrasound of the ankle and foot in rheumatology.

    PubMed

    Micu, Mihaela C; Nestorova, Rodina; Petranova, Tzvetanka; Porta, Francesco; Radunovic, Goran; Vlad, Violeta; Iagnocco, Annamaria

    2012-03-01

    In the last years musculoskeletal ultrasound (US) has become a very useful imaging tool for the evaluation of rheumatic patients and a natural extension of the clinical examination of the ankle and foot. Musculoskeletal US allows the evaluation of the symptomatic and asymptomatic ankle and foot with a detailed analysis of a wide range of elementary lesions at the level of different anatomical structures and their distribution in early or long standing disease. In inflammatory pathology, it helps in the assessment of the disease activity and severity at the joint, tendon or entheseal level and in the detection of subclinical pathological features in early disease or residual activity after therapy. Moreover, US guided procedures allow accurate diagnostic and therapeutic interventions. It is a valuable imaging method that can be also used in the follow up of the treated patients (systemic and/ or local therapies or surgical procedures), being a patient friendly, non-invasive, and quick to perform method. The aim of this paper is to review the US technique of scanning and the indications of US in the analysis of the ankle and foot in rheumatic diseases.

  1. Experimental and computational analysis of composite ankle-foot orthosis.

    PubMed

    Zou, Dequan; He, Tao; Dailey, Michael; Smith, Kirk E; Silva, Matthew J; Sinacore, David R; Mueller, Michael J; Hastings, Mary K

    2014-01-01

    Carbon fiber (CF) ankle-foot orthoses (AFOs) can improve gait by increasing ankle plantar-flexor power and improving plantar-flexor ankle joint moment and energy efficiency compared with posterior leaf spring AFOs made of thermoplastic. However, fabricating a CF AFO to optimize the performance of the individual user may require multiple AFOs and expensive fabrication costs. Finite element analysis (FEA) models were developed to predict the mechanical behavior of AFOs in this study. Three AFOs, two made of CF composite material and one made of thermoplastic material, were fabricated and then mechanically tested to produce force-displacement data. The FEA models were validated by comparing model predictions with mechanical testing data performed under the same loading and boundary conditions. The actual mechanical testing demonstrated that CF performs better than thermoplastic. The simulation results showed that FEA models produced accurate predictions for both types of orthoses. The relative error of the energy return ratio predicted by the CF AFO FEA model developed in this study is less than 3%. We conclude that highly accurate FEA models will allow orthotists to improve CF AFO fabrication without wasting resources (time and money) on trial and error fabrications that are expensive and do not consistently improve AFO and user performance.

  2. Changes in Balancing Ability of Athletes With Chronic Ankle Instability After Foot Orthotics Application and Rehabilitation Exercises

    PubMed Central

    Lee, Hong-Jae; Lim, Kil-Byung; Jung, Tae-Ho; Kim, Dug-Young

    2013-01-01

    Objective To compare the effect of foot orthotics and rehabilitation exercises by assessing balancing ability and joint proprioception in athletes who have chronic ankle instability. Methods Forty-one athletes who visited hospitals due to chronic ankle instability were randomly assigned to two groups. One group had ankle rehabilitation exercises while the other group had the same rehabilitation exercises as well as foot orthotics. Joint position sense of the ankle joint was examined by using an isokinetic exercise machine. Balancing abilities categorized into static, dynamic and functional balance abilities were evaluated by using computerized posturography. We tested the subjects before and after the four-week rehabilitation program. Results After the four-week treatment, for joint reposition sense evaluation, external 75% angle evaluation was done, revealing that the group with the application of foot orthotics improved by -1.07±1.64 on average, showing no significant difference between the two groups (p>0.05). Static, dynamic and functional balancing abilities using balance masters were evaluated, revealing that the two groups improved in some items, but showing no significant difference between them (p>0.05). Conclusion This study found that athletes with chronic ankle instability who had foot orthotics applied for four weeks improved their proprioceptive and balancing abilities, but did not show additional treatment effects compared with rehabilitation exercise treatment. PMID:24020033

  3. A Multiple Degree of Freedom Lower Extremity Isometric Device to Simultaneously Quantify Hip, Knee, and Ankle Torques.

    PubMed

    Sánchez, Natalia; Acosta, Ana Maria; Stienen, Arno H A; Dewald, Julius P A

    2015-09-01

    Characterization of the joint torque coupling strategies used in the lower extremity to generate maximal and submaximal levels of torque at either the hip, knee, or ankle is lacking. Currently, there are no available isometric devices that quantify all concurrent joint torques in the hip, knee, and ankle of a single leg during maximum voluntary torque generation. Thus, joint-torque coupling strategies in the hip, knee, and concurrent torques at ankle and/or coupling patterns at the hip and knee driven by the ankle have yet to be quantified. This manuscript describes the design, implementation, and validation of a multiple degree of freedom, lower extremity isometric device (the MultiLEIT) that accurately quantifies simultaneous torques at the hip, knee, and ankle. The system was mechanically validated and then implemented with two healthy control individuals and two post-stroke individuals to test usability and patient acceptance. Data indicated different joint torque coupling strategies used by both healthy individuals. In contrast, data showed the same torque coupling patterns in both post-stroke individuals, comparable to those described in the clinic. Successful implementation of the MultiLEIT can contribute to the understanding of the underlying mechanisms responsible for abnormal movement patterns and aid in the design of therapeutic interventions.

  4. Surgical outcomes after excision of pigmented villonodular synovitis localized to the ankle and hindfoot without adjuvant therapy.

    PubMed

    Sung, Ki-Sun; Ko, Kyung Rae

    2015-01-01

    Although a benign disorder, pigmented villonodular synovitis (PVNS) has a high rate of recurrence. Because of the high incidence of recurrence and concern about destruction of the affected joint, several adjuvant therapies have been promoted without a clear standard treatment strategy. We reviewed cases of PVNS affecting the ankle and hindfoot joints (ankle and/or subtalar joints) treated with surgical resection without adjuvant therapy in an effort to identify the incidence of PVNS recurrence after excision without adjuvant therapy. Of the 10 cases with a mean follow-up duration of 33.2 ± 19.8 months, 4 (40%) developed a recurrence, with a mean interval of 6 (range 3 to 14) months. At the final follow-up visit, the mean American Orthopaedic Foot and Ankle Society ankle-hindfoot score was 86.6 ± 12. The clinical outcomes of PVNS affecting the ankle and hindfoot joints are associated with a relatively high incidence of recurrence, and additional clinical investigation comparing the incidence of recurrence in patients undergoing excision versus excision with adjuvant therapy is needed for us to better understand this condition and provide more informed recommendations to our patients.

  5. A Multiple Degree of Freedom Lower Extremity Isometric Device to Simultaneously Quantify Hip, Knee and Ankle Torques

    PubMed Central

    Sánchez, Natalia; Acosta, Ana Maria; Stienen, Arno H.A.

    2015-01-01

    Characterization of the joint torque coupling strategies used in the lower extremity to generate maximal and submaximal levels of torque at either the hip, knee or ankle is lacking. Currently, there are no available isometric devices that quantify all concurrent joint torques in the hip, knee and ankle of a single leg during maximum voluntary torque generation. Thus, joint-torque coupling strategies in the hip, knee and concurrent torques at ankle and/or coupling patterns at the hip and knee driven by the ankle have yet to be quantified. This manuscript describes the design, implementation and validation of a multiple degree of freedom, lower extremity isometric device (the MultiLEIT) that accurately quantifies simultaneous torques at the hip, knee and ankle. The system was mechanically validated and then implemented with two healthy control individuals and two post-stroke individuals to test usability and patient acceptance. Data indicated different joint torque coupling strategies used by both healthy individuals. In contrast, data showed the same torque coupling patterns in both post-stroke individuals, comparable to those described in the clinic. Successful implementation of the MultiLEIT can contribute to the understanding of the underlying mechanisms responsible for abnormal movement patterns and aid in the design of therapeutic interventions. PMID:25163064

  6. Unlocking the talus by eversion limits medial ankle injury risk during external rotation.

    PubMed

    Button, Keith D; Wei, Feng; Haut, Roger C

    2015-10-15

    Eversion prior to excessive external foot rotation has been shown to predispose the anterior tibiofibular ligament (ATiFL) to failure, yet protect the anterior deltoid ligament (ADL) from failure despite high levels of foot rotation. The purpose of the current study was to measure the rotations of both the subtalar and talocrural joints during foot external rotation at sub-failure levels in either a neutral or a pre-everted position as a first step towards understanding the mechanisms of injury in previous studies. Fourteen (seven pairs) cadaver lower extremities were externally rotated 20° in either a pre-everted or neutral configuration, without producing injury. Motion capture was performed to track the tibia, talus, and calcaneus motions, and a joint coordinate system was used to analyze motions of the two joints. While talocrural joint rotation was greater in the neutral ankle (13.3±2.0° versus 10.5±2.7°, p=0.006), subtalar joint rotation was greater in the pre-everted ankle (2.4±1.9° versus 1.1±1.0°, p=0.014). Overall, the talocrural joint rotated more than the subtalar joint (11.9±2.8° versus 1.8±1.6°, p<0.001). It was proposed that the calcaneus and talus 'lock' in a neutral position, but 'unlock' when the ankle is everted prior to rotation. This locking/unlocking mechanism could be responsible for an increased subtalar rotation, but decreased talocrural rotation when the ankle is pre-everted, protecting the ADL from failure. This study may provide information valuable to the study of external rotation kinematics and injury risk.

  7. Management of sports injuries of the foot and ankle: an update.

    PubMed

    Ballal, M S; Pearce, C J; Calder, J D F

    2016-07-01

    Sporting injuries around the ankle vary from simple sprains that will resolve spontaneously within a few days to severe injuries which may never fully recover and may threaten the career of a professional athlete. Some of these injuries can be easily overlooked altogether or misdiagnosed with potentially devastating effects on future performance. In this review article, we cover some of the common and important sporting injuries involving the ankle including updates on their management and outcomes. Cite this article: Bone Joint J 2016;98-B:874-83.

  8. Supervised rehabilitation versus home exercise in the treatment of acute ankle sprains: a systematic review.

    PubMed

    Feger, Mark A; Herb, C Collin; Fraser, John J; Glaviano, Neal; Hertel, Jay

    2015-04-01

    In competitive sports medicine, supervised rehabilitation is the standard of care; in the general population, unsupervised home exercise is more common. We systematically reviewed randomized, controlled trials comparing outcomes for supervised rehabilitation versus home exercise programs. Supervised rehabilitation programs resulted in (1) less pain and subjective instability, (2) greater gains in ankle strength and joint position sense, and (3) inconclusive results regarding prevention of recurrent ankle sprains. We recommend supervised rehabilitation over home exercise programs owing to the improved short-term patient-recorded evidence with a strength-of-recommendation taxonomy level of evidence of 2B. PMID:25818717

  9. Supervised rehabilitation versus home exercise in the treatment of acute ankle sprains: a systematic review.

    PubMed

    Feger, Mark A; Herb, C Collin; Fraser, John J; Glaviano, Neal; Hertel, Jay

    2015-04-01

    In competitive sports medicine, supervised rehabilitation is the standard of care; in the general population, unsupervised home exercise is more common. We systematically reviewed randomized, controlled trials comparing outcomes for supervised rehabilitation versus home exercise programs. Supervised rehabilitation programs resulted in (1) less pain and subjective instability, (2) greater gains in ankle strength and joint position sense, and (3) inconclusive results regarding prevention of recurrent ankle sprains. We recommend supervised rehabilitation over home exercise programs owing to the improved short-term patient-recorded evidence with a strength-of-recommendation taxonomy level of evidence of 2B.

  10. Management of sports injuries of the foot and ankle: an update.

    PubMed

    Ballal, M S; Pearce, C J; Calder, J D F

    2016-07-01

    Sporting injuries around the ankle vary from simple sprains that will resolve spontaneously within a few days to severe injuries which may never fully recover and may threaten the career of a professional athlete. Some of these injuries can be easily overlooked altogether or misdiagnosed with potentially devastating effects on future performance. In this review article, we cover some of the common and important sporting injuries involving the ankle including updates on their management and outcomes. Cite this article: Bone Joint J 2016;98-B:874-83. PMID:27365464

  11. Differences in gait characteristics between total hip, knee, and ankle arthroplasty patients: a six-month postoperative comparison

    PubMed Central

    2013-01-01

    Background The recovery of gait ability is one of the primary goals for patients following total arthroplasty of lower-limb joints. The aim of this study was to objectively compare gait differences of patients after unilateral total hip arthroplasty (THA), total knee arthroplasty (TKA) and total ankle arthroplasty (TAA) with a group of healthy controls. Methods A total of 26 TAA, 26 TKA and 26 THA patients with a mean (± SD) age of 64 (± 9) years were evaluated six months after surgery and compared with 26 matched healthy controls. Subjects were asked to walk at self-selected normal and fast speeds on a validated pressure mat. The following spatiotemporal gait parameters were measured: walking velocity, cadence, single-limb support (SLS) time, double-limb support (DLS) time, stance time, step length and step width. Results TAA and TKA patients walked slower than controls at normal (p<0.05) and fast speeds (p<0.01). The involved side of TAA and TKA patients showed shorter SLS compared to controls at both normal and fast speeds (p<0.01). Regardless of walking speed, the uninvolved side of TAA and TKA patients demonstrated longer stance time and shorter step length than controls (p<0.01). TAA patients showed shorter SLS of the involved side, longer stance time and shorter step length of the uninvolved side compared to the contralateral side at both normal and fast speeds (p<0.001). Conclusions Gait disability after unilateral lower-limb joint arthroplasty was more marked for distal than for proximal joints at six months after surgery, with a proximal-to-distal progression in the impairment (TAA>TKA>THA). THA patients demonstrated no gait differences compared with controls. In contrast, TAA and TKA patients still demonstrated gait differences compared to controls, with slower walking velocity and reduced SLS in the involved limb. In addition, TAA patients presented marked side-to-side asymmetries in gait characteristics. PMID:23731906

  12. Find an Orthopaedic Foot and Ankle MD/DO

    MedlinePlus

    ... AOFAS / FootCareMD / Find a Surgeon Find an Orthopaedic Foot & Ankle Surgeon Page Content The Orthopaedic Distinction Who are Orthopaedic Foot & Ankle Surgeons? Orthopaedic foot and ankle surgeons are ...

  13. TOTAL ANKLE ARTHROPLASTY: BRAZILIAN EXPERIENCE WITH THE HINTEGRA PROSTHESIS

    PubMed Central

    Nery, Caio; Fernandes, Túlio Diniz; Réssio, Cibele; Fuchs, Mauro Luiz; Godoy Santos, Alexandre Leme de; Ortiz, Rafael Trevisan

    2015-01-01

    Ankle arthrosis is becoming more and more common. The search for solutions that preserve joint function has led to a new generation of prosthesis with three components and more degrees of freedom. This paper presents the results achieved for ten patients treated with the HINTEGRA Prosthesis (Integra, New Deal), through collaborative action between the Foot and Ankle Groups of the Orthopedics and Traumatology divisions of Escola Paulista de Medicina, Unifesp, and the School of Medicine of the University of São Paulo (USP). The ten patients (six women and four men, aged between 29 and 66 years), underwent a surgical procedure consisting of Hintermann's technique, between January and June 2005. They were evaluated at prearranged intervals, and the data were subjected to statistical analysis. The surgery led to a significant improvement in ankle mobility. Radiological evaluation showed no signs of loosening or failure in the prosthetic components in any of the patients studied. Although the complication rate in our sample was high, it was equivalent to the rates found by other authors, and directly represents the learning curve associate with this kind of procedure. Four years after the procedure, it was found that the patients pain levels had significantly decreased, and that their functional patterns had significantly improved, with AOFAS and Hintermann scores indicating results that were excellent for 20%, good for 70% and poor for 10%. Treatment of ankle arthritis by means of total arthroplasty using the HINTEGRA prosthesis was capable of providing good results over an average observation period of four years. PMID:27022527

  14. Explosive Resistance Training Increases Rate of Force Development in Ankle Dorsiflexors and Gait Function in Adults With Cerebral Palsy.

    PubMed

    Kirk, Henrik; Geertsen, Svend S; Lorentzen, Jakob; Krarup, Kasper B; Bandholm, Thomas; Nielsen, Jens B

    2016-10-01

    Kirk, H, Geertsen, SS, Lorentzen, J, Krarup, KB, Bandholm, T, and Nielsen, JB. Explosive resistance training increases rate of force development in ankle dorsiflexors and gait function in adults with cerebral palsy. J Strength Cond Res 30(10): 2749-2760, 2016-Alterations in passive elastic properties of muscles and reduced ability to quickly generate muscle force contribute to impaired gait function in adults with cerebral palsy (CP). In this study, we investigated whether 12 weeks of explosive and progressive heavy-resistance training (PRT) increases rate of force development of ankle dorsiflexors (RFDdf), improves gait function, and affects passive ankle joint stiffness in adults with CP. Thirty-five adults (age: 36.5; range: 18-59 years) with CP were nonrandomly assigned to a PRT or nontraining control (CON) group in this explorative trial. The PRT group trained ankle dorsiflexion, plantarflexion, leg press, hamstring curls, abdominal curls, and back extension 3 days per week for 12 weeks, with 3 sets per exercise and progressing during the training period from 12 to 6 repetition maximums. RFDdf, 3-dimensional gait analysis, functional performance, and ankle joint passive and reflex-mediated muscle stiffness were evaluated before and after. RFDdf increased significantly after PRT compared to CON. PRT also caused a significant increase in toe lift late in swing and a significantly more dorsiflexed ankle joint at ground contact and during stance. The increased toe-lift amplitude was correlated to the increased RFDdf (r = 0.73). No other between-group differences were observed. These findings suggest that explosive PRT may increase RFDdf and facilitate larger range of movement in the ankle joint during gait. Explosive PRT should be tested in clinical practice as part of a long-term training program for adults with CP.

  15. Which ankle fractures require syndesmotic stabilization?

    PubMed

    van den Bekerom, Michel P J; Lamme, Bas; Hogervorst, Mike; Bolhuis, Hugo W

    2007-01-01

    Syndesmotic ruptures associated with ankle fractures are most commonly caused by external rotation of the foot, eversion of the talus within the ankle mortise, and excessive dorsiflexion. The distal tibiofibular syndesmosis consists of the anterior inferior tibiofibular ligament, posterior inferior tibiofibular ligament, and interosseous ligament, and it is essential for stability of the ankle mortise. Despite the numerous biomechanical and clinical studies pertaining to ankle fractures, there are no uniform recommendations regarding the use of the syndesmotic screw for specific injury patterns and fracture types. The objective of this review was to formulate recommendations for clinical practice related to the use of syndesmotic screw placement. PMID:17980843

  16. Nonoperative management of athletic ankle injuries.

    PubMed

    Vegso, J J; Harmon, L E

    1982-03-01

    Few injuries in sports are more ubiquitous than those involving the ankle. Athletes in some endeavors, notably football and basketball, routinely have their ankles prophylactically taped at a cost of hundreds of thousands of dollars and, probably, millions of man hours. Other sports, such as skiing, involve encasement of the foot, ankle and lower leg in plastic and foam to the extent of almost complete exclusion of motion. In spite of these rather heroic measures, ankle injuries continue to constitute a significant threat to athletes in these and most other activities.

  17. The GIY-YIG Type Endonuclease Ankyrin Repeat and LEM Domain-Containing Protein 1 (ANKLE1) Is Dispensable for Mouse Hematopoiesis

    PubMed Central

    Braun, Juliane; Meixner, Arabella; Brachner, Andreas; Foisner, Roland

    2016-01-01

    Ankyrin repeat and LEM-domain containing protein 1 (ANKLE1) is a GIY-YIG endonuclease with unknown functions, mainly expressed in mouse hematopoietic tissues. To test its potential role in hematopoiesis we generated Ankle1-deficient mice. Ankle1Δ/Δ mice are viable without any detectable phenotype in hematopoiesis. Neither hematopoietic progenitor cells, myeloid and lymphoid progenitors, nor B and T cell development in bone marrow, spleen and thymus, are affected in Ankle1Δ/Δ-mice. Similarly embryonic stress erythropoiesis in liver and adult erythropoiesis in bone marrow and spleen appear normal. To test whether ANKLE1, like the only other known GIY-YIG endonuclease in mammals, SLX1, may contribute to Holliday junction resolution during DNA repair, Ankle1-deficient cells were exposed to various DNA-damage inducing agents. However, lack of Ankle1 did not affect cell viability and, unlike depletion of Slx1, Ankle1-deficiency did not increase sister chromatid exchange in Bloom helicase-depleted cells. Altogether, we show that lack of Ankle1 does neither affect mouse hematopoiesis nor DNA damage repair in mouse embryonic fibroblasts, indicating a redundant or non-essential function of ANKLE1 in mouse. PMID:27010503

  18. Optimal management of ankle syndesmosis injuries

    PubMed Central

    Porter, David A; Jaggers, Ryan R; Barnes, Adam Fitzgerald; Rund, Angela M

    2014-01-01

    Syndesmosis injuries occur when there is a disruption of the distal attachment of the tibia and fibula. These injuries occur commonly (up to 18% of ankle sprains), and the incidence increases in the setting of athletic activity. Recognition of these injuries is key to preventing long-term morbidity. Diagnosis and treatment of these injuries requires a thorough understanding of the normal anatomy and the role it plays in the stability of the ankle. A complete history and physical examination is of paramount importance. Patients usually experience an external rotation mechanism of injury. Key physical exam features include detailed documentation about areas of focal tenderness (syndesmosis and deltoid) and provocative maneuvers such as the external rotation stress test. Imaging workup in all cases should consist of radiographs with the physiologic stress of weight bearing. If these images are inconclusive, then further imaging with external rotation stress testing or magnetic resonance imaging are warranted. Nonoperative treatment is appropriate for stable injuries. Unstable injuries should be treated operatively. This consists of stabilizing the syndesmosis with either trans-syndesmotic screw or tightrope fixation. In the setting of a concomitant Weber B or C fracture, the fibula is anatomically reduced and stabilized with a standard plate and screw construct. Proximal fibular fractures, as seen in the Maisonneuve fracture pattern, are not repaired operatively. Recent interest is moving toward repair of the deltoid ligament, which may provide increased stability, especially in rehabilitation protocols that involve early weight bearing. Rehabilitation is focused on allowing patients to return to their pre-injury activities as quickly and safely as possible. Protocols initially focus on controlling swelling and recovery from surgery. The protocols then progress to restoration of motion, early protected weight bearing, restoration of strength, and eventually a

  19. Small Joint Arthroscopy in the Foot.

    PubMed

    Reeves, Christopher L; Shane, Amber M; Payne, Trevor; Cavins, Zac

    2016-10-01

    Arthroscopy has advanced in the foot and ankle realm, leading to new innovative techniques designed toward treatment of small joint abnormality. A range of abnormalities that are currently widespread for arthroscopic treatment in larger joints continues to be translated to congruent modalities in the small joints. Small joint arthroscopy offers relief from foot ailments with a noninvasive element afforded by arthroscopy. Early studies have found comparable results from arthroscopic soft tissue procedures as well as arthrodesis of the small joints when compared with the standard open approach. PMID:27599441

  20. Study on changes in skin extensibility during the development of joint contracture due to joint immobilization in rats

    PubMed Central

    Tasaka, Atsushi; Ono, Takeya; Oki, Sadaaki; Umei, Namiko; Ishikura, Hideki; Aihara, Kazuki; Sato, Yuta; Matsumoto, Tomohiro

    2015-01-01

    [Purpose] The purpose of this study was to elucidate whether skin extensibility decreases when a contracture develops as a result of joint immobilization. [Subjects] This study was conducted on six female Wistar rats. [Methods] The rats were divided into two experimental groups. In the immobilized group, the right ankle joints were immobilized in complete plantar flexion by plaster casts for two weeks. In the control group, the left ankle joints had no intervention. On the final day, skin extensibility was determined from a length-tension curve by collecting skin from the posterior aspect of the ankle joint and using a tensile strength tester. [Results] Compared with the control group, the immobilized group showed a significant decrease in skin extensibility. [Conclusion] The results demonstrated that the extensibility of the skin itself decreases when joint contracture develops. PMID:26504268

  1. Balance assessments for predicting functional ankle instability and stable ankles.

    PubMed

    Ross, Scott E; Linens, Shelley W; Wright, Cynthia J; Arnold, Brent L

    2011-10-01

    A number of instrumented and non-instrumented measures are used to detect balance deficits associated with functional ankle instability (FAI). Determining outcome measures that detect balance deficits associated with FAI might assist clinicians in identifying impairments that may otherwise go undetected with less responsive balance measures. Thus, our objective was to determine the balance measure that best predicted ankle group membership (FAI or stable ankle). Participants included 17 subjects without a history of ankle sprains (168±9 cm, 66±14 kg, 24±5 yr) and 17 subjects with FAI (172±9 cm, 71±11 kg, 22±3 yr). Balance trials were performed without vision and subjects stood on a single leg as motionless as possible for 20s. Balance was quantified with center-of-pressure measures (velocity, area) and error score. Measures were positively correlated with each other (r range: 0.60-0.76). The multifactorial model with all three measures best predicted group membership (F((3,30))=7.20, P=0.001; R(2)=0.42; percent classified correctly=77%), and was followed by the multifactorial model with resultant center-of-pressure velocity and error score (F((2,31))=8.73, P=0.001; R(2)=0.36; percent classified correctly=74%). The resultant center-of-pressure velocity (F((1,32))=13.46, P=0.001; R(2)=0.30; percent classified correctly=74%; unique variance=12.7%) and error score (F((1,32))=12.51, P=0.001; R(2)=0.28; percent classified correctly=71%; unique variance=12.0%) predicted group membership; however, 95th percentile center-of-pressure area ellipse did not (F((1,32))=4.16, P=0.05; R(2)=0.12; percent classified correctly=65%; unique variance=5.8%). A multifactorial single leg balance assessment is best for predicting group membership. COPV is the best single predictor of group membership, but clinicians may use error score to identify deficits associated with FAI if force plates are not available. PMID:21868225

  2. Ankle blood pressure as a predictor of total and cardiovascular mortality

    PubMed Central

    Hietanen, Heikki; Pääkkönen, Rauni; Salomaa, Veikko

    2008-01-01

    Background The ankle blood pressure is commonly used as a ratio to the brachial blood pressure, called ankle-brachial index (ABI). Very few studies have considered the independent value of the ankle blood pressure without indexing it to the brachial blood pressure. We examined the value of ankle blood pressure, together with the exercise blood pressure, as a predictor of cardiovascular (CVD) and total mortality. Methods A prospective follow-up study of 3,858 consecutive ambulatory patients (mean age 51 years, 65,9% male) referred to a symptom-limited exercise test between August 1989 and December 1995. The cohort was followed up for all-cause and CVD mortality until December 31, 2004, by record linkage with the National Causes-of-Death Register. The independent value of ankle blood pressure as a predictor of cardiovascular and total mortality was assessed using Cox proportional hazards modelling. Results The average follow-up time was 14 years, during which 346 persons died, 108 of them due to CVD. Persons with normal (<140 mmHg) resting brachial blood pressure, ankle blood pressure < 175 mmHg and exercise blood pressure at moderate exercise level ≤215 mmHg at baseline investigation, had the best prognosis and were taken as the reference category. Among persons with elevated ankle blood pressure (≥175 mmHg) but normal or borderline resting brachial pressure and normal exercise blood pressure (≤215 mmHg) at moderate exercise level the multivariate-adjusted hazard ratios (HR, 95% confidence interval) for CVD and total mortality were 2.70 (1.52 – 4.80) and 2.13 (1.58 – 2.85), respectively. Similar and equally significant HRs were observed in persons with both elevated ankle blood pressure and elevated exercise blood pressure, as well as in those persons with elevated exercise blood pressure but ankle blood pressure < 175 mmHg. Conclusion These results suggest that the ankle blood pressure has an independent value as a marker of arterial stiffness or

  3. Pseudoaneurysm of the posterior tibial artery after manipulation under anesthesia of a total ankle replacement.

    PubMed

    Brigido, Stephen A; Bleazey, Scott T; Oskin, Timothy C; Protzman, Nicole M

    2013-01-01

    Although pseudoaneurysm of the posterior tibial artery has been reported, no investigators have discussed the development of a pseudoaneurysm after manipulation under anesthesia of a total ankle replacement. We present the case of a 59-year-old female with end-stage post-traumatic tibiotalar joint disease who underwent an uneventful INBONE® Total Ankle Replacement. She experienced continued postoperative pain and impingement after physical therapy. Consequently, she underwent manipulation under anesthesia. The manipulation provided complete and immediate pain relief. However, she developed a pseudoaneurysm of the posterior tibial artery that required vascular repair. She recovered uneventfully and was ambulating free of pain with improved functionality. Although manipulation under anesthesia of a total ankle replacement is a valuable, noninvasive tool that can provide near-immediate pain relief, it is important to realize that this distal arterial injury, although uncommon, is a possibility.

  4. Simulation of an ankle rehabilitation system based on scotch- yoke mechanism

    NASA Astrophysics Data System (ADS)

    Racu (Cazacu, C. M.; Doroftei, I.; Plesu, Ghe; Doroftei, I. A.

    2016-08-01

    Due to injuries that occur on the ankle joint, everyday all around the world, more and more rehabilitation devices have been developed in recent years. The prices for ankle rehabilitation systems are still high, thus we developed a new device that we indented to be low cost and easy to manufacture. A model of an ankle rehabilitation device is presented in this paper. The device has two degrees of freedom, for flexion-extension and inversion-eversion move, and will ensure functionality with minimum dimensions. For the 3D model that we design, the dimensions are taken so that the proposed system will ensure functionality but also have a small dimensions and low mass, considering the physiological dimensions of the foot and lower leg.

  5. Validating a new computed tomography atlas for grading ankle osteoarthritis.

    PubMed

    Cohen, Michael M; Vela, Nathan D; Levine, Jason E; Barnoy, Eran A

    2015-01-01

    As the most common joint disease, osteoarthritis (OA) poses a significant source of pain and disability. It can be defined by classic radiographic findings, particular symptoms, or a combination of the 2. Although specific grading scales have been developed to evaluate OA in various joints, such as the shoulder, hip, and knee, no definitive classification system is available for grading OA in the ankle. The purpose of the present study was to create and validate a standardized atlas for grading (or staging) ankle osteoarthritis using computed tomography (CT) and "hallmark" findings noted on coronal, sagittal, and axial views extrapolated from the Kellgren-Lawrence radiographic scale. The CT scans of 226 patients at the Miami Veterans Affairs Medical Center were reviewed. An atlas was derived from a retrospective review of 30 remaining CT scans taken from July 2008 to November 2011. After this review, 3 orthogonal static CT images, obtained from 11 remaining patients, were chosen to represent the various stages on the OA scale and were used to test the validity of the atlas developed by 2 of us (M.M.C. and N.D.V.). A multispecialty panel of 9 examiners, excluding ourselves, independently rated the 11 CT scan subjects. The differences among examiners and specialties were calculated, including an intra-examiner agreement for 2 separate readings spaced 9 months apart. Although the small number of subspecialty examiners made the intraspecialty comparisons difficult to validate, the findings nevertheless indicated excellent agreement among all specialty groups, with good intra-investigational (intraclass correlation coefficient 0.962 and 1) inter-investigational (intraclass correlation coefficient 0.851) values. These results appeared to validate the CT ankle OA atlas, which we believe will be a valuable clinical and research tool, one that will likely be more beneficial than less relevant generalized OA grading scales in use today.

  6. A wearable device for monitoring and prevention of repetitive ankle sprain.

    PubMed

    Attia, Mohammed; Taher, Mona F

    2015-08-01

    This study presents the design and implementation of a wearable wireless device, connected to a smart phone, which monitors and prevents repetitive ankle sprain due to chronic ankle instability (CAI). The device prevents this common foot injury by electrical stimulation of the peroneal muscles using surface electrodes which causes dorsiflexion of the foot. This is done after measuring ankle kinematics using inertial motion sensors and predicting ankle sprain. The prototype implemented here has a fast response time of 7 msec which enables prevention of ankle sprain before ligament damage occurs. Wireless communication between the components of the device, in addition to their small size, low cost and low power consumption, makes it unobtrusive, easy to wear and not hinder normal activities. The device connects via Bluetooth to an android smart phone application for continuous data logging and reporting to keep track of the incidences of possible ankle sprain and correction. This is a significant feature of this device since it enables monitoring of patients with CAI and quantifying progression of the condition or improvement in the case of treatment. PMID:26737335

  7. Behavioral effect of knee joint motion on body's center of mass during human quiet standing.

    PubMed

    Yamamoto, Akio; Sasagawa, Shun; Oba, Naoko; Nakazawa, Kimitaka

    2015-01-01

    The balance control mechanism during upright standing has often been investigated using single- or double-link inverted pendulum models, involving the ankle joint only or both the ankle and hip joints, respectively. Several studies, however, have reported that knee joint motion during quiet standing cannot be ignored. This study aimed to investigate the degree to which knee joint motion contributes to the center of mass (COM) kinematics during quiet standing. Eight healthy adults were asked to stand quietly for 30s on a force platform. Angular displacements and accelerations of the ankle, knee, and hip joints were calculated from kinematic data obtained by a motion capture system. We found that the amplitude of the angular acceleration was smallest in the ankle joint and largest in the hip joint (ankle < knee < hip). These angular accelerations were then substituted into three biomechanical models with or without the knee joint to estimate COM acceleration in the anterior-posterior direction. Although the "without-knee" models greatly overestimated the COM acceleration, the COM acceleration estimated by the "with-knee" model was similar to the actual acceleration obtained from force platform measurement. These results indicate substantial effects of knee joint motion on the COM kinematics during quiet standing. We suggest that investigations based on the multi-joint model, including the knee joint, are required to reveal the physiologically plausible balance control mechanism implemented by the central nervous system. PMID:25248799

  8. Behavioral effect of knee joint motion on body's center of mass during human quiet standing.

    PubMed

    Yamamoto, Akio; Sasagawa, Shun; Oba, Naoko; Nakazawa, Kimitaka

    2015-01-01

    The balance control mechanism during upright standing has often been investigated using single- or double-link inverted pendulum models, involving the ankle joint only or both the ankle and hip joints, respectively. Several studies, however, have reported that knee joint motion during quiet standing cannot be ignored. This study aimed to investigate the degree to which knee joint motion contributes to the center of mass (COM) kinematics during quiet standing. Eight healthy adults were asked to stand quietly for 30s on a force platform. Angular displacements and accelerations of the ankle, knee, and hip joints were calculated from kinematic data obtained by a motion capture system. We found that the amplitude of the angular acceleration was smallest in the ankle joint and largest in the hip joint (ankle < knee < hip). These angular accelerations were then substituted into three biomechanical models with or without the knee joint to estimate COM acceleration in the anterior-posterior direction. Although the "without-knee" models greatly overestimated the COM acceleration, the COM acceleration estimated by the "with-knee" model was similar to the actual acceleration obtained from force platform measurement. These results indicate substantial effects of knee joint motion on the COM kinematics during quiet standing. We suggest that investigations based on the multi-joint model, including the knee joint, are required to reveal the physiologically plausible balance control mechanism implemented by the central nervous system.

  9. Estimation of quasi-stiffness and propulsive work of the human ankle in the stance phase of walking.

    PubMed

    Shamaei, Kamran; Sawicki, Gregory S; Dollar, Aaron M

    2013-01-01

    Characterizing the quasi-stiffness and work of lower extremity joints is critical for evaluating human locomotion and designing assistive devices such as prostheses and orthoses intended to emulate the biological behavior of human legs. This work aims to establish statistical models that allow us to predict the ankle quasi-stiffness and net mechanical work for adults walking on level ground. During the stance phase of walking, the ankle joint propels the body through three distinctive phases of nearly constant stiffness known as the quasi-stiffness of each phase. Using a generic equation for the ankle moment obtained through an inverse dynamics analysis, we identify key independent parameters needed to predict ankle quasi-stiffness and propulsive work and also the functional form of each correlation. These parameters include gait speed, ankle excursion, and subject height and weight. Based on the identified form of the correlation and key variables, we applied linear regression on experimental walking data for 216 gait trials across 26 subjects (speeds from 0.75-2.63 m/s) to obtain statistical models of varying complexity. The most general forms of the statistical models include all the key parameters and have an R(2) of 75% to 81% in the prediction of the ankle quasi-stiffnesses and propulsive work. The most specific models include only subject height and weight and could predict the ankle quasi-stiffnesses and work for optimal walking speed with average error of 13% to 30%. We discuss how these models provide a useful framework and foundation for designing subject- and gait-specific prosthetic and exoskeletal devices designed to emulate biological ankle function during level ground walking.

  10. Estimation of Quasi-Stiffness and Propulsive Work of the Human Ankle in the Stance Phase of Walking

    PubMed Central

    Shamaei, Kamran; Sawicki, Gregory S.; Dollar, Aaron M.

    2013-01-01

    Characterizing the quasi-stiffness and work of lower extremity joints is critical for evaluating human locomotion and designing assistive devices such as prostheses and orthoses intended to emulate the biological behavior of human legs. This work aims to establish statistical models that allow us to predict the ankle quasi-stiffness and net mechanical work for adults walking on level ground. During the stance phase of walking, the ankle joint propels the body through three distinctive phases of nearly constant stiffness known as the quasi-stiffness of each phase. Using a generic equation for the ankle moment obtained through an inverse dynamics analysis, we identify key independent parameters needed to predict ankle quasi-stiffness and propulsive work and also the functional form of each correlation. These parameters include gait speed, ankle excursion, and subject height and weight. Based on the identified form of the correlation and key variables, we applied linear regression on experimental walking data for 216 gait trials across 26 subjects (speeds from 0.75–2.63 m/s) to obtain statistical models of varying complexity. The most general forms of the statistical models include all the key parameters and have an R2 of 75% to 81% in the prediction of the ankle quasi-stiffnesses and propulsive work. The most specific models include only subject height and weight and could predict the ankle quasi-stiffnesses and work for optimal walking speed with average error of 13% to 30%. We discuss how these models provide a useful framework and foundation for designing subject- and gait-specific prosthetic and exoskeletal devices designed to emulate biological ankle function during level ground walking. PMID:23555839

  11. Incidence and Severity of Foot and Ankle Injuries in Men’s Collegiate American Football

    PubMed Central

    Lievers, W. Brent; Adamic, Peter F.

    2015-01-01

    Background: American football is an extremely physical game with a much higher risk of injury than other sports. While many studies have reported the rate of injury for particular body regions or for individual injuries, very little information exists that compares the incidence or severity of particular injuries within a body region. Such information is critical for prioritizing preventative interventions. Purpose: To retrospectively analyze epidemiological data to identify the most common and most severe foot and ankle injuries in collegiate men’s football. Study Design: Descriptive epidemiology study. Methods: Injury data were obtained from the National Collegiate Athletic Association (NCAA) Injury Surveillance System (ISS) for all foot and ankle injuries during the 2004-2005 to 2008-2009 seasons. Injuries were analyzed in terms of incidence and using multiple measures of severity (time loss, surgeries, medical disqualifications). This frequency and severity information is summarized in tabular form as well as in a 4 × 4 quantitative injury risk assessment matrix (QIRAM). Results: The rate of foot and ankle injuries was 15 per 10,000 athletic exposures (AEs). Five injuries were found to be responsible for more than 80% of all foot and ankle injuries: lateral ankle ligament sprains, syndesmotic (high ankle) sprains, medial ankle ligament sprains, midfoot injuries, and first metatarsophalangeal joint injuries. Ankle dislocations were found to be the most severe in terms of median time loss (100 days), percentage of surgeries (83%), and percentage of medical disqualifications (94%), followed by metatarsal fractures (38 days, 36%, and 49%, respectively) and malleolus fractures (33 days, 41%, and 59%, respectively). Statistical analysis suggests that the 3 measures of severity are highly correlated (r > 0.94), thereby justifying the use of time loss as a suitable proxy for injury severity in the construction of the QIRAM. Conclusion: Based on the QIRAM analysis

  12. Within-socket myoelectric prediction of continuous ankle kinematics for control of a powered transtibial prosthesis

    NASA Astrophysics Data System (ADS)

    Farmer, Samuel; Silver-Thorn, Barbara; Voglewede, Philip; Beardsley, Scott A.

    2014-10-01

    Objective. Powered robotic prostheses create a need for natural-feeling user interfaces and robust control schemes. Here, we examined the ability of a nonlinear autoregressive model to continuously map the kinematics of a transtibial prosthesis and electromyographic (EMG) activity recorded within socket to the future estimates of the prosthetic ankle angle in three transtibial amputees. Approach. Model performance was examined across subjects during level treadmill ambulation as a function of the size of the EMG sampling window and the temporal ‘prediction’ interval between the EMG/kinematic input and the model’s estimate of future ankle angle to characterize the trade-off between model error, sampling window and prediction interval. Main results. Across subjects, deviations in the estimated ankle angle from the actual movement were robust to variations in the EMG sampling window and increased systematically with prediction interval. For prediction intervals up to 150 ms, the average error in the model estimate of ankle angle across the gait cycle was less than 6°. EMG contributions to the model prediction varied across subjects but were consistently localized to the transitions to/from single to double limb support and captured variations from the typical ankle kinematics during level walking. Significance. The use of an autoregressive modeling approach to continuously predict joint kinematics using natural residual muscle activity provides opportunities for direct (transparent) control of a prosthetic joint by the user. The model’s predictive capability could prove particularly useful for overcoming delays in signal processing and actuation of the prosthesis, providing a more biomimetic ankle response.

  13. Balance control under different passive contributions of the ankle extensors: quiet standing on inclined surfaces.

    PubMed

    Sasagawa, Shun; Ushiyama, Junichi; Masani, Kei; Kouzaki, Motoki; Kanehisa, Hiroaki

    2009-07-01

    Human bipedal stance is often modeled as a single inverted pendulum that pivots at the ankle joints in the sagittal plane. Because the center of body mass is usually maintained in front of the ankle joints, ankle extensor torque is continuously required to prevent the body from falling. During quiet standing, both passive and active mechanisms contribute to generate the ankle extensor torque counteracting gravity. This study aimed to investigate the active stabilization mechanism in more detail. Eight healthy subjects were requested to stand quietly on three different surfaces of 1) toes-up, 2) level, and 3) toes-down. Surface electromyogram (EMG) was recorded from the medial head of the gastrocnemius (MG), soleus (SOL), and tibialis anterior muscles. Inclination angle of the body was simultaneously measured. As a result, we found that EMG activities of MG and SOL were lowest during the toes-up standing and highest during the toes-down, indicating that increased (decreased) passive contribution required less (more) extensor torque generated by active muscle contraction. Frequency domain analysis also revealed that sway-related modulation of the ankle extensor activity (0.12-4.03 Hz) was unchanged among the three foot inclinations. On the other hand, isometric contraction strength of these muscles increased as the slope declined (toes-up < level < toes-down). These results support the idea that by regulating the isometric contraction strength, the CNS maintains a constant level of muscle tone and resultant ankle stiffness irrespective of the passive contribution. Such control scheme would be crucial when we consider the low bandwidth of the intermittent controller.

  14. Ankle and Other Signatures in Uhecr

    NASA Astrophysics Data System (ADS)

    Berezinsky, Veniamin

    2015-03-01

    The interaction signatures of UHE protons propagating through CMB are discussed. Much attention is given to ankle, which starting from 1963 is usually interpreted as a feature of transition from galactic to extragalactic cosmic rays. We argue here that this interpretation is now excluded. It gives more credit to alternative explanation of the ankle as an intrinsic part of the pair-production dip.

  15. Current concepts review: ankle fractures.

    PubMed

    Arastu, M H; Demcoe, R; Buckley, R E

    2012-01-01

    Ankle fractures are common injuries that require meticulous technique in order to optimise outcome. The Lauge-Hansen and Danis-Weber classifications in addition to careful evaluation of the injury mechanism can help guide treatment but surgeons must be aware that there are injury patterns that will not always fit the afore mentioned patterns. The principles of atraumatic soft tissue handling, rigid internal fixation and early range of motion exercises are critical for successfully treating these injuries. There are still areas of treatment uncertainty and future directed research is needed in order to address some of these questions.

  16. Design and validation of a platform robot for determination of ankle impedance during ambulation.

    PubMed

    Rouse, Elliott J; Hargrove, Levi J; Peshkin, Michael A; Kuiken, Todd A

    2011-01-01

    In order to provide natural, biomimetic control to recently developed powered ankle prostheses, we must characterize the impedance of the ankle during ambulation tasks. To this end, a platform robot was developed that can apply an angular perturbation to the ankle during ambulation and simultaneously acquire ground reaction force data. In this study, we detail the design of the platform robot and characterize the impedance of the ankle during quiet standing. Subjects were perturbed by a 3° dorsiflexive ramp perturbation with a length of 150 ms. The impedance was defined parametrically, using a second order model to map joint angle to the torque response. The torque was determined using the inverted pendulum assumption, and impedance was identified by the least squares best estimate, yielding an average damping coefficient of 0.03 ± 0.01 Nms/° and an average stiffness coefficient of 3.1 ± 1.2 Nm/°. The estimates obtained by the proposed platform robot compare favorably to those published in the literature. Future work will investigate the impedance of the ankle during ambulation for powered prosthesis controller development.

  17. Tumours of the foot and ankle.

    PubMed

    Khan, Zeeshan; Hussain, Shakir; Carter, Simon R

    2015-09-01

    Sarcomas are rare tumours and particularly rarer in the foot and ankle region. The complex anatomy of the foot and ankle makes it unique and hence poses a challenge to the surgeon for limb salvage surgery. Other lesions found in the foot and ankle region are benign bone and soft tissue tumours, metastasis and infection. The purpose of this article is to discuss the relevance of the complex anatomy of the foot and ankle in relation to tumours, clinical features, their general management principles and further discussion about some of the more common bone and soft tissue lesions. Discussion of every single bone and soft tissue lesion in the foot and ankle region is beyond the scope of this article.

  18. [Study on the control of dynamic artificial limb ankle based on central pattern generator].

    PubMed

    Guo, Xin; Xu, Caiyu; Li, Mingyue; Su, Longtao

    2014-12-01

    In order to obtain the normal gait for the prosthesis-carrier with the change of external environment and gait, we designed a model of dynamic ankle prosthesis and control system and introduced the strategy of central pattern generator (CPG) about the moving trail of dynamic ankle prosthesis. The dynamic parts, which are incorporated in the model of dynamic ankle prosthesis, provide power in order to have anthropic function and character. The tool of Matlab/simulink was used to simulate the strategy. The simulation results showed that the strategy of CPG learn- ing control in this study was effective and could track the reference trail rapidly and fit the moving trail of a person's normal limb. It can make the prosthetic timely regulation and action, enhance the prosthetic intelligence. It has im- portant practical value for intelligent prosthesis development based on this analysis of technology.

  19. Screening Characteristics of Ultrasonography in Detection of Ankle Fractures

    PubMed Central

    Shojaee, Majid; Hakimzadeh, Farhad; Mohammadi, Parisa; Sabzghabaei, Anita; Manouchehrifar, Mohammad; Arhami Dolatabadi, Ali

    2016-01-01

    Introduction: Ankle fracture is one of the most common joint fractures. X-ray and physical examination are its main methods of diagnosis. Recently, ultrasonography (US) is considered as a simple and non-invasive method of fracture diagnosis. This study evaluated the diagnostic accuracy of US in detection of ankle fracture in comparison to plain radiography. Methods: In this diagnostic accuracy study, which was done in emergency departments of Imam Hossein and Shohadaye Tajrish hospitals, Tehran, Iran, during 2014, 141 patients with suspected diagnosis of distal leg or ankle fracture were examined by US and radiography (gold standard), independently. Screening performance characteristics of US in detection of distal leg fractures were calculated using SPSS version 21. Results: 141 patients with the mean age of 34 ± 11.52 years (range: 15 – 50) were evaluated (75.9% male). Radiography confirmed ankle fracture in 102 (72.3%) patients. There was a significant correlation between the results of US and radiography [Agreement: 95%; kappa: 0.88 (95% CI: 0.80-0.97); P < 0.001]. The screening performance characteristics of US in detection ankle fracture were as follows: sensitivity 98.9% (95% CI: 93.5% - 99.9%), specificity 86.4% (95% CI: 71.9%-94.3%), PPV 94.1% (95% CI: 87.1% - 97.6%), NPV 97.4% (95% CI: 84.9% - 99.8%), PLR 16 (95% CI: 7.3 – 34.8), and NLR 0.02 (95% CI: 0.003 – 0.182). The area under the ROC curve of US in this regard was 95.8 (95% CI: 91.9 ± 99.7). Conclusion: According to the results of this study, we can use US as an accurate and non-invasive method with high sensitivity and specificity in diagnosis of malleolus fractures. However, the inherent limitations of US such as operator dependency should be considered in this regard. PMID:27800538

  20. The Split Second Effect: The Mechanism of How Equinus Can Damage the Human Foot and Ankle

    PubMed Central

    Amis, James

    2016-01-01

    We are currently in the process of discovering that many, if not the majority, of the non-traumatic acquired adult foot and ankle problems are caused by a singular etiology: non-neuromuscular equinus or the isolated gastrocnemius contracture. There is no question that this biomechanical association exists and in time much more will be uncovered. There are three basic questions that must be answered: why would our calves tighten as we normally age, how does a tight calf, or equinus, actually cause problems remotely in the foot and ankle, and how do the forces produced by equinus cause so many seemingly unrelated pathologies in the foot and ankle? The purpose of this paper is to address the second question: how does a tight calf mechanically cause problems remotely in the foot and ankle? There has been little evidence in the literature addressing the biomechanical mechanisms by which equinus creates damaging forces upon the foot and ankle, and as a result, a precise, convincing mechanism is still lacking. Thus, the mere concept that equinus has anything to do with foot pathology is generally unknown or disregarded. The split second effect, described here, defines exactly how the silent equinus contracture creates incremental and significant damage and injury to the human foot and ankle resulting in a wide variety of pathological conditions. The split second effect is a dissenting theory based on 30 years of clinical and academic orthopedic foot and ankle experience, keen clinical observation along the way, and review of the developing literature, culminating in examination of many hours of slow motion video of normal and abnormal human gait. To my knowledge, no one has ever described the mechanism in detail this precise. PMID:27512692

  1. The Split Second Effect: The Mechanism of How Equinus Can Damage the Human Foot and Ankle.

    PubMed

    Amis, James

    2016-01-01

    We are currently in the process of discovering that many, if not the majority, of the non-traumatic acquired adult foot and ankle problems are caused by a singular etiology: non-neuromuscular equinus or the isolated gastrocnemius contracture. There is no question that this biomechanical association exists and in time much more will be uncovered. There are three basic questions that must be answered: why would our calves tighten as we normally age, how does a tight calf, or equinus, actually cause problems remotely in the foot and ankle, and how do the forces produced by equinus cause so many seemingly unrelated pathologies in the foot and ankle? The purpose of this paper is to address the second question: how does a tight calf mechanically cause problems remotely in the foot and ankle? There has been little evidence in the literature addressing the biomechanical mechanisms by which equinus creates damaging forces upon the foot and ankle, and as a result, a precise, convincing mechanism is still lacking. Thus, the mere concept that equinus has anything to do with foot pathology is generally unknown or disregarded. The split second effect, described here, defines exactly how the silent equinus contracture creates incremental and significant damage and injury to the human foot and ankle resulting in a wide variety of pathological conditions. The split second effect is a dissenting theory based on 30 years of clinical and academic orthopedic foot and ankle experience, keen clinical observation along the way, and review of the developing literature, culminating in examination of many hours of slow motion video of normal and abnormal human gait. To my knowledge, no one has ever described the mechanism in detail this precise. PMID:27512692

  2. Fixation orientation in ankle fractures with syndesmosis injury.

    PubMed

    Nimick, Craig J; Collman, David R; Lagaay, Pieter

    2013-01-01

    Accurate reduction of the syndesmosis has been shown to be an important prognostic factor for functional outcome in ankle injuries that disrupt the syndesmosis. The purpose of the present case series was to assess the fixation orientation and the position of the fibula within the tibial incisura after open reduction and internal fixation of ankle fractures with syndesmosis injury. Computed tomography was used to assess the accuracy of the reduction. Twelve patients were included in the present case series. A ratio representing the relationship between the tibia and fibula and the orientation of the syndesmotic fixation was measured preoperatively and postoperatively and compared with the uninjured contralateral ankle, representing the patient's normal anatomy. The measurements were accomplished electronically to one tenth of 1 mm using Stentor Intelligent Informatics, I-site, version 3.3.1 (Phillips Electronics; Andover, MA). Posteriorly oriented syndesmotic fixation caused posterior translation of the fibula with respect to the tibia and anteriorly oriented syndesmotic fixation caused anterior translation. PMID:23540759

  3. Immediate Weight-Bearing after Ankle Fracture Fixation

    PubMed Central

    Harnden, Emily

    2015-01-01

    We believe that a certain subset of surgical ankle fracture patients can be made weight-bearing as tolerated immediately following surgery. Immediate weight-bearing as tolerated (IWBAT) allows patients to return to ambulation and activities of daily living faster and may facilitate rehabilitation. A prospectively gathered orthopaedic trauma database at a Level 1 trauma center was reviewed retrospectively to identify patients who had ORIF after unstable ankle injuries treated by the senior author. Patients were excluded if they were not IWBAT based on specific criteria or if they did meet followup requirement. Only 1/26 patients was noted to have loss of fixation. This was found at the 6-week followup and was attributed to a missed syndesmotic injury. At 2-week followup, 2 patients had peri-incisional erythema that resolved with a short course of oral antibiotics. At 6-week followup, 20 patients were wearing normal shoes and 6 patients continued to wear the CAM Boot for comfort. To conclude, IWBAT in a certain subset of patients with stable osteosynthesis following an ankle fracture could potentially be a safe alternative to a period of protected weight-bearing. PMID:25785201

  4. Synergistic interaction between ankle and knee during hopping revealed through induced acceleration analysis.

    PubMed

    João, Filipa; Veloso, António; Cabral, Sílvia; Moniz-Pereira, Vera; Kepple, Thomas

    2014-02-01

    The forces produced by the muscles can deliver energy to a target segment they are not attached to, by transferring this energy throughout the other segments in the chain. This is a synergistic way of functioning, which allows muscles to accelerate or decelerate segments in order to reach the target one. The purpose of this study was to characterize the contribution of each lower extremity joint to the vertical acceleration of the body's center of mass during a hopping exercise. To accomplish this, an induced acceleration analysis was performed using a model with eight segments. The results indicate that the strategies produced during a hopping exercise rely on the synergy between the knee and ankle joints, with most of the vertical acceleration being produced by the knee extensors, while the ankle plantar flexors act as stabilizers of the foot. This synergy between the ankle and the knee is perhaps a mechanism that allows the transfer of power from the knee muscles to the ground, and we believe that in this particular task the net action of the foot and ankle moments is to produce a stable foot with little overall acceleration.

  5. The role of ankle bracing for prevention of ankle sprain injuries.

    PubMed

    Gross, Michael T; Liu, Hsin-Yi

    2003-10-01

    Lateral ankle sprains are one of the most common injuries incurred in recreational and competitive athletics. These injuries have a significant impact in terms of cost, athletic participation, and activities of daily living. Prophylactic ankle braces are often used to reduce the risk of injury recurrence when individuals return to athletic participation. The purpose of this clinical commentary is to review the literature and provide our own experience relative to the use of prophylactic ankle bracing. Relatively high incidence rates of ankle sprain injury have been reported for basketball and soccer athletes, military trainees, and individuals with a previous history of ankle sprain injury. Semirigid and laced ankle braces have significantly reduced the incidence of initial and recurrent ankle sprain injuries in athletic and military samples. With few exceptions, these braces do not appear to affect functional performance adversely. The prophylactic use of semirigid ankle braces appears warranted to reduce the incidence of initial and, in particular, recurrent ankle sprain injuries for individuals who participate in activities that have the highest risk for these injuries. Additional research is needed to evaluate the many new braces that are available and in use and their influence on the incidence of ankle sprain injury and functional performance.

  6. Footwear and ankle stability in the basketball player.

    PubMed

    Petrov, O; Blocher, K; Bradbury, R L; Saxena, A; Toy, M L

    1988-04-01

    Ankle stability in basketball players is affected by footwear. Athletic shoe manufacturers have introduced specialized lacing systems and high-top performance shoes to improve ankle stability. These performance shoes not only aid in preventing ankle injuries, but also protect injured ankles.

  7. Lower Extremity Joint Moments During Carrying Tasks in Children

    PubMed Central

    Stevermer, Catherine A.; Miller, Ross H.; Edwards, W. Brent; Schwab, Charles V.

    2015-01-01

    Farm youth often carry loads that are proportionally large and/or heavy, and field measurements have determined that these tasks are equivalent to industrial jobs with high injury risks. The purpose of this study was to determine the effects of age, load amount, and load symmetry on lower extremity joint moments during carrying tasks. Three age groups (8–10 years, 12–14 years, adults), three load amounts (0%, 10%, 20% BW), and three load symmetry levels (unilateral large bucket, unilateral small bucket, bilateral small buckets) were tested. Inverse dynamics was used to determine maximum ankle, knee, and hip joint moments. Ankle dorsiflexion, ankle inversion, ankle eversion, knee adduction, and hip extension moments were significantly higher in 8–10 and 12–14 year olds. Ankle plantar flexion, ankle inversion, knee extension, and hip extension moments were significantly increased at 10% and 20% BW loads. Knee and hip adduction moments were significantly increased at 10% and 20% BW loads when carrying a unilateral large bucket. Of particular concern are increased ankle inversion and eversion moments for children, along with increased knee and hip adduction moments for heavy, asymmetrical carrying tasks. Carrying loads bilaterally instead of unilaterally avoided increases in knee and hip adduction moments with increased load amount. PMID:21975284

  8. The influence of ankle sprain injury on muscle activation during hip extension.

    PubMed

    Bullock-Saxton, J E; Janda, V; Bullock, M I

    1994-08-01

    The likely influence of a localised injury in a distal joint on the function of proximal muscles is an important consideration in assessment and treatment of musculoskeletal injuries. However, little experimental evidence in humans exists in this area. Accordingly, a controlled study was carried out, in which the function of muscles at the hip was compared between subjects who had suffered previous severe unilateral ankle sprain and matched control subjects. The pattern of activation of the gluteus maximus, the hamstring muscles and the ipsilateral and contralateral erector spinae muscles was monitored through the use of surface electromyography during hip extension from prone lying. Analyses revealed that the pattern of muscle activation in subjects with previous injury differed markedly from normal control subjects, and that changes appeared to occur on both the uninjured and the injured sides of the body. A significant difference between the two groups was the delay in onset of activation of the gluteus maximus in previously injured subjects. The existence of remote changes in muscle function following injury found in this study emphasise the importance of extending assessment beyond the side and site of injury.

  9. Flexor bias of joint position in humans during spaceflight

    NASA Technical Reports Server (NTRS)

    McCall, G. E.; Goulet, C.; Boorman, G. I.; Roy, R. R.; Edgerton, V. R.

    2003-01-01

    The ability to estimate ankle and elbow joint position was tested before, during, and after a 17-day spaceflight. Subjects estimated targeted joint angles during isovelocity (IsoV) joint movements with agonist muscle groups either active or relaxed. These movements included elbow extension (EE) and elbow flexion (EF), and plantarflexion (PF) and dorsiflexion (DF) of the ankle. Subjects also estimated these joint positions while moving the dynamometer at their chosen (variable) velocity (VarV) during EE and PF. For IsoV tests, no differences were observed between active and passive movements for either the ankle or elbow. Compared with those of pre-flight test days, estimates of targeted elbow joint angles were approximately 5 degrees to 15 degrees more flexed in-flight, and returned toward the pre-flight values during recovery. The spaceflight effects for the ankle were inconsistent and less prevalent than those for the elbow. The VarV PF test condition for the 120 degrees target angle at the ankle exhibited approximately 5 degrees to 7 degrees more DF target angle estimates in-flight compared with those pre- or post-flight. In contrast, during IsoV PF there was a tendency for ankle estimates to be approximately 2 degrees to 3 degrees more PF after 2-3 days exposure to spaceflight. These data indicate that during spaceflight the perception of elbow extension is greater than actuality, and are consistent with the interpretation that microgravity induced a flexor bias in the estimation of the actual elbow joint position. Moreover, these effects in joint proprioception during spaceflight were observed in individual isolated single-joint movements during tasks in which vestibular function in maintaining posture were minimal.

  10. Inversion and eversion strengths in the weightbearing ankle of young women. Effects of plantar flexion and basketball shoe height.

    PubMed

    Ottaviani, R A; Ashton-Miller, J A; Wojtys, E M

    2001-01-01

    Maximum isometric ankle inversion and eversion muscle strengths were measured under full unipedal weightbearing in 20 healthy young adult women. When the women wore a low-top shoe, the mean (standard deviation) maximum external eversion moments resisted with the foot in 0 degrees and 32 degrees of ankle plantar flexion were 24.1 (7.6) and 24.1 (8.1) N x m, respectively, while the corresponding values for maximum inversion moments resisted were 14.7 (6.8) and 17.4 (6.4) N x m, respectively. Both shoe height and ankle plantar flexion affected the overall inversion moment resisted by 17% (P = 0.03) at 0 degrees of ankle plantar flexion to 11.9% (P = 0.003) at 32 degrees of ankle plantar flexion. However, neither shoe height nor ankle plantar flexion significantly affected the maximum eversion moment resisted. Although eversion muscle strength of the young women averaged 39% less than the corresponding value found in young men, the sex difference was not significant when ankle strengths were normalized by body size (body weight x height). Thus, when data from healthy young men and women were averaged, eversion and inversion strengths averaged 1.6% and 2.7%, respectively, of body weight x height.

  11. Position versus force control: using the 2-DOF robotic ankle trainer to assess ankle's motor control.

    PubMed

    Farjadian, Amir B; Nabian, Mohsen; Hartman, Amber; Corsino, Johnathan; Mavroidis, Constantinos; Holden, Maureen K

    2014-01-01

    An estimated of 2,000,000 acute ankle sprains occur annually in the United States. Furthermore, ankle disabilities are caused by neurological impairments such as traumatic brain injury, cerebral palsy and stroke. The virtually interfaced robotic ankle and balance trainer (vi-RABT) was introduced as a cost-effective platform-based rehabilitation robot to improve overall ankle/balance strength, mobility and control. The system is equipped with 2 degrees of freedom (2-DOF) controlled actuation along with complete means of angle and torque measurement mechanisms. Vi-RABT was used to assess ankle strength, flexibility and motor control in healthy human subjects, while playing interactive virtual reality games on the screen. The results suggest that in the task with 2-DOF, subjects have better control over ankle's position vs. force.

  12. Ankle motion influences the external knee adduction moment and may predict who will respond to lateral wedge insoles?: an ancillary analysis from the SILK trial

    PubMed Central

    Chapman, G.J.; Parkes, M.J.; Forsythe, L.; Felson, D.T.; Jones, R.K.

    2015-01-01

    Summary Objective Lateral wedge insoles are a potential simple treatment for medial knee osteoarthritis (OA) patients by reducing the external knee adduction moment (EKAM). However in some patients, an increase in their EKAM is seen. Understanding the role of the ankle joint complex in the response to lateral wedge insoles is critical in understanding and potentially identifying why some patients respond differently to lateral wedge insoles. Method Participants with medial tibiofemoral OA underwent gait analysis whilst walking in a control shoe and a lateral wedge insole. We evaluated if dynamic ankle joint complex coronal plane biomechanical measures could explain and identify those participants that increased (biomechanical non-responder) or decreased (biomechanical responder) EKAM under lateral wedge conditions compared to the control shoe. Results Of the 70 participants studied (43 male), 33% increased their EKAM and 67% decreased their EKAM. Overall, lateral wedge insoles shifted the centre of foot pressure laterally, increased eversion of the ankle/subtalar joint complex (STJ) and the eversion moment compared to the control condition. Ankle angle at peak EKAM and peak eversion ankle/STJ complex angle in the control condition predicted if individuals were likely to decrease EKAM under lateral wedge conditions. Conclusions Coronal plane ankle/STJ complex biomechanical measures play a key role in reducing EKAM when wearing lateral wedge insoles. These findings may assist in the identification of those individuals that could benefit more from wearing lateral wedge insoles. PMID:25749010

  13. 3D kinematics of the tarsal joints from magnetic resonance images

    NASA Astrophysics Data System (ADS)

    Hirsch, Bruce E.; Udupa, Jayaram K.; Okereke, Enyi; Hillstrom, Howard J.; Siegler, Sorin; Ringleb, Stacie I.; Imhauser, Carl W.

    2001-09-01

    We have developed a method for analyzing motion at skeletal joints based on the 3D reconstruction of magnetic resonance (MR) image data. Since the information about each voxel in MR images includes its location in the scanner, it follows that information is available for each organ whose 3D surface is computed from a series of MR slices. In addition, there is information on the shape and orientation of each organ, and the contact areas of adjacent bones. By collecting image data in different positions we can calculate the motion of the individual bones. We have used this method to study human foot bones, in order to understand normal and abnormal foot function. It has been used to evaluate patients with tarsal coalitions, various forms of pes planus, ankle sprains, and several other conditions. A newly described feature of this system is the ability to visualize the contact area at a joint, as determined by the region of minimum distance. The display of contact area helps understand abnormal joint function. Also, the use of 3D imaging reveals motions in joints which cannot otherwise be visualized, such as the subtalar joint, for more accurate diagnosis of joint injury.

  14. Knee joint proprioception in normal volunteers and patients with anterior cruciate ligament tears, taking special account of the effect of a knee bandage.

    PubMed

    Jerosch, J; Prymka, M

    1996-01-01

    Proprioception of the knee joint was tested in 30 healthy volunteers with clinically inconspicuous knee joints. To examine proprioception, an angle reproduction test was performed. We could not document any differences between the left and the right knee joint or between men and women. At the mid-range, proprioception was worse compared with the end range of motion. In addition, 25 patients with an isolated rupture of the anterior cruciate ligament were evaluated, 14 before and 11 after operative anterior cruciate ligament (ACL) reconstruction. Preoperatively, there was a significant deterioration of proprioception compared with the control group. We were able to show a positive influence of a knee bandage on the proprioception of the injured knee. Patients after ACL reconstruction showed no significantly better proprioception compared with the preoperative group.

  15. The synovial microenvironment of osteoarthritic joints alters RNA-seq expression profiles of human primary articular chondrocytes.

    PubMed

    Lewallen, Eric A; Bonin, Carolina A; Li, Xin; Smith, Jay; Karperien, Marcel; Larson, A Noelle; Lewallen, David G; Cool, Simon M; Westendorf, Jennifer J; Krych, Aaron J; Leontovich, Alexey A; Im, Hee-Jeong; van Wijnen, Andre J

    2016-10-15

    Osteoarthritis (OA) is a disabling degenerative joint disease that prompts pain and has limited treatment options. To permit early diagnosis and treatment of OA, a high resolution mechanistic understanding of human chondrocytes in normal and diseased states is necessary. In this study, we assessed the biological effects of OA-related changes in the synovial microenvironment on chondrocytes embedded within anatomically intact cartilage from joints with different pathological grades by next generation RNA-sequencing (RNA-seq). We determined the transcriptome of primary articular chondrocytes derived from anatomically unaffected knees and ankles, as well as from joints affected by OA. The GALAXY bioinformatics platform was used to facilitate biological interpretations. Comparisons of patient samples by k-means, hierarchical clustering and principal component analyses together reveal that primary chondrocytes exhibit OA grade-related differences in gene expression, including genes involved in cell-adhesion, ECM production and immune response. We conclude that diseased synovial microenvironments in joints with different histopathological OA grades directly alter gene expression in chondrocytes. One ramification of this finding is that anatomically intact cartilage from OA joints is not an ideal source of healthy chondrocytes, nor should these specimens be used to generate a normal baseline for the molecular characterization of diseased joints. PMID:27378743

  16. Joint swelling

    MedlinePlus

    Swelling of a joint ... Joint swelling may occur along with joint pain . The swelling may cause the joint to appear larger or abnormally shaped. Joint swelling can cause pain or stiffness. After an ...

  17. Failure to restore sagittal tibiotalar alignment in total ankle arthroplasty: Its relationship to the axis of the tibia and the positioning of the talar component.

    PubMed

    Cho, J; Yi, Y; Ahn, T K; Choi, H J; Park, C H; Chun, D I; Lee, J S; Lee, W C

    2015-11-01

    The purpose of this study was to evaluate the change in sagittal tibiotalar alignment after total ankle arthroplasty (TAA) for osteoarthritis and to investigate factors affecting the restoration of alignment. This retrospective study included 119 patients (120 ankles) who underwent three component TAA using the Hintegra prosthesis. A total of 63 ankles had anterior displacement of the talus before surgery (group A), 49 had alignment in the normal range (group B), and eight had posterior displacement of the talus (group C). Ankles in group A were further sub-divided into those in whom normal alignment was restored following TAA (41 ankles) and those with persistent displacement (22 ankles). Radiographic and clinical results were assessed. Pre-operatively, the alignment in group A was significantly more varus than that in group B, and the posterior slope of the tibial plafond was greater (p < 0.01 in both cases). The posterior slope of the tibial component was strongly associated with restoration of alignment: ankles in which the alignment was restored had significantly less posterior slope (p < 0.001). An anteriorly translated talus was restored to a normal position after TAA in most patients. We suggest that surgeons performing TAA using the Hintegra prosthesis should aim to insert the tibial component at close to 90° relative to the axis of the tibia, hence reducing posterior soft-tissue tension and allowing restoration of normal tibiotalar alignment following surgery.

  18. The knees and ankles in sport and veteran military parachutists.

    PubMed Central

    Murray-Leslie, C F; Lintott, D J; Wright, V

    1977-01-01

    112 actively parachuting sport (free fall) parachutists with more than 200 descents each and 109 veteran military parachutists no longer active returned a postal questionnaire about their parachuting activities, injuries, and current and past musculoskeletal symptoms. A high frequency of fractures and injuries was reported by each group, both in relation to parachuting and to other activities. 58 sport parachutists aged 23 to 57 years (mean 33 - 3 years) had weight-bearing anteroposterior and lateral radiographs taken of each knee. These showed a prevalence of radiological osteoarthrosis of 10 - 4% which was mild in degree in all but one knee in one subject. 46 ex-military parachutists aged 50 to 70 years (mean 55 - 2 years) had weight-bearing anteroposterior radiographs taken of both knees and showed a prevalence of radiological osteroarthrosis of 41 - 3%. Moderate and severe changes were found in 10 - 9%. In both groups of parachutists six of the eight knee joints showing either moderate or severe radiological osteroarthrosis had been subjected to a previous meniscectomy. Forty ex-military parachutists had anteroposterior radiographs of the ankles (talotibial articulation) and showed a prevalence of osteoarthrosis of 17 - 5%, with the majority showing mild changes. There was a poor correlation between radiological osteoarthrosis, ankle symptoms, and previous fractures. With the reservation that the great majority of the sport group are still young (95% aged less than 50 years), it is concluded that parachutists as a group do not show an increased prevalence of radiological osteoarthrosis of the knee or ankle. PMID:409358

  19. Clinical application of a modular ankle robot for stroke rehabilitation

    PubMed Central

    Forrester, Larry W.; Roy, Anindo; Goodman, Ronald N.; Rietschel, Jeremy; Barton, Joseph E.; Krebs, Hermano Igo; Macko, Richard F.

    2015-01-01

    Background Advances in our understanding of neuroplasticity and motor learning post-stroke are now being leveraged with the use of robotics technology to enhance physical rehabilitation strategies. Major advances have been made with upper extremity robotics, which have been tested for efficacy in multi-site trials across the subacute and chronic phases of stroke. In contrast, use of lower extremity robotics to promote locomotor re-learning has been more recent and presents unique challenges by virtue of the complex multi-segmental mechanics of gait. Objectives Here we review a programmatic effort to develop and apply the concept of joint-specific modular robotics to the paretic ankle as a means to improve underlying impairments in distal motor control that may have a significant impact on gait biomechanics and balance. Methods An impedance controlled ankle robot module (anklebot) is described as a platform to test the idea that a modular approach can be used to modify training and measure the time profile of treatment response. Results Pilot studies using seated visuomotor anklebot training with chronic patients are reviewed, along with results from initial efforts to evaluate the anklebot's utility as a clinical tool for assessing intrinsic ankle stiffness. The review includes a brief discussion of future directions for using the seated anklebot training in the earliest phases of sub-acute therapy, and to incorporate neurophysiological measures of cerebro-cortical activity as a means to reveal underlying mechanistic processes of motor learning and brain plasticity associated with robotic training. Conclusions Finally we conclude with an initial control systems strategy for utilizing the anklebot as a gait training tool that includes integrating an Internal Model-based adaptive controller to both accommodate individual deficit severities and adapt to changes in patient performance. PMID:23949045

  20. Conservative and surgical treatment of the chronic Charcot foot and ankle

    PubMed Central

    Güven, Mehmet Fatih; Karabiber, Atakan; Kaynak, Gökhan; Öğüt, Tahir

    2013-01-01

    Charcot neuroarthropathy (CN) is a severe joint disease in the foot and ankle that can result in fracture, permanent deformity, and limb loss. It is a serious and potentially limb-threatening lower-extremity late complication of diabetes mellitus. The aim of this manuscript was to evaluate modern concepts of chronic CN through a review of the available literature and to integrate a perspective of management from the authors’ extensive experience. PMID:23919114

  1. Lichen simplex chronicus on the ankle (image)

    MedlinePlus

    Lichen simplex chronicus on the ankle: Lichen simplex chronicus is also known as neurodermatitis. A minor itch may encourage scratching which increases the irritation, leading to more scratching. This ...

  2. Sports Injuries to the Foot and Ankle

    MedlinePlus

    ... Field Hockey Football Injuries Golf Injuries Lacrosse Rugby Running Soccer Softball Tennis Volleyball Find an ACFAS Physician ... Foot and Ankle Although golf does not involve running or jumping, injuries can occur to the foot ...

  3. Better Way to Treat Seniors' Ankle Fractures?

    MedlinePlus

    ... quality of life can suffer as they lose mobility," added Willett. He is a professor of orthopedics, ... two groups in terms of pain, ankle motion, mobility or quality of life, the study found. Patients ...

  4. Fibular osteochondroma presenting as chronic ankle sprain.

    PubMed

    Montella, B J; O'Farrell, D A; Furr, W S; Harrelson, J M

    1995-04-01

    A 19-year-old baseball player was referred for assessment of recurrent sprains of the right ankle. This was found to be secondary to a palsy of the common peroneal nerve that was compressed by an osteochondroma of the fibular neck. The lesion was resected from the fibula and the patient made a complete recovery. We present this case as an example of a rare underlying problem in a patient who was initially diagnosed as having a sports-related ankle injury.

  5. Endoscopic Ankle Lateral Ligament Graft Anatomic Reconstruction.

    PubMed

    Michels, Frederick; Cordier, Guillaume; Guillo, Stéphane; Stockmans, Filip

    2016-09-01

    Chronic instability is a common complication of lateral ankle sprains. If nonoperative treatment fails, a surgical repair or reconstruction may be indicated. Today, endoscopic techniques to treat ankle instability are becoming more popular. This article describes an endoscopic technique, using a step-by-step approach, to reconstruct the ATFL and CFL with a gracilis graft. The endoscopic technique is reproducible and safe with regard to the surrounding anatomic structures. Short and midterm results confirm the benefits of this technique. PMID:27524711

  6. Shank Muscle Strength Training Changes Foot Behaviour during a Sudden Ankle Supination

    PubMed Central

    Hagen, Marco; Lescher, Stephanie; Gerhardt, Andreas; Lahner, Matthias; Felber, Stephan; Hennig, Ewald M.

    2015-01-01

    Background The peroneal muscles are the most effective lateral stabilisers whose tension braces the ankle joint complex against excessive supination. The purpose of this study was to identify the morphological and biomechanical effects of two machine-based shank muscle training methods. Methods Twenty-two healthy male recreationally active sports students performed ten weeks of single-set high resistance strength training with 3 training sessions per week. The subjects conducted subtalar pronator/supinator muscle training (ST) with the right leg by using a custom-made apparatus; the left foot muscles were exercised with machine-based talocrural plantar and dorsiflexor training (TT). Muscle strength (MVIC), muscle volume and foot biomechanics (rearfoot motion, ground reaction forces, muscle reaction times) during a sudden ankle supination were recorded before and after the intervention. Results Compared to TT, ST resulted in significantly higher pronator (14% vs. 8%, P<0.01) and supinator MVIC (25% vs. 12%, P<0.01). During sudden foot inversions, both ST and TT resulted in reduced supination velocity (-12%; P<0.01). The muscle reaction onset time was faster after the training in peroneus longus (PL) (P<0.01). Muscle volume of PL (P<0.01) and TA (P<0.01) increased significantly after both ST and TT. Conclusion After both ST and TT, the ankle joint complex is mechanically more stabilised against sudden supinations due to the muscle volume increase of PL and TA. As the reduced supination velocities indicate, the strength training effects are already present during free-fall. According to a sudden ankle supination in standing position, both machine-based dorsiflexor and pronator strength training is recommended for enhancing the mechanical stability of the ankle. PMID:26110847

  7. Clinical measures of hip and foot-ankle mechanics as predictors of rearfoot motion and posture.

    PubMed

    Souza, Thales R; Mancini, Marisa C; Araújo, Vanessa L; Carvalhais, Viviane O C; Ocarino, Juliana M; Silva, Paula L; Fonseca, Sérgio T

    2014-10-01

    Health professionals are frequently interested in predicting rearfoot pronation during weight-bearing activities. Previous inconsistent results regarding the ability of clinical measures to predict rearfoot kinematics may have been influenced by the neglect of possible combined effects of alignment and mobility at the foot-ankle complex and by the disregard of possible influences of hip mobility on foot kinematics. The present study tested whether using a measure that combines frontal-plane bone alignment and mobility at the foot-ankle complex and a measure of hip internal rotation mobility predicts rearfoot kinematics, in walking and upright stance. Twenty-three healthy subjects underwent assessment of forefoot-shank angle (which combines varus bone alignments at the foot-ankle complex with inversion mobility at the midfoot joints), with a goniometer, and hip internal rotation mobility, with an inclinometer. Frontal-plane kinematics of the rearfoot was assessed with a three-dimensional system, during treadmill walking and upright stance. Multivariate linear regressions tested the predictive strength of these measures to inform about rearfoot kinematics. The measures significantly predicted (p ≤ 0.041) mean eversion-inversion position, during walking (r(2) = 0.40) and standing (r(2) = 0.31), and eversion peak in walking (r(2) = 0.27). Greater values of varus alignment at the foot-ankle complex combined with inversion mobility at the midfoot joints and greater hip internal rotation mobility are related to greater weight-bearing rearfoot eversion. Each measure (forefoot-shank angle and hip internal rotation mobility) alone and their combination partially predicted rearfoot kinematics. These measures may help detecting foot-ankle and hip mechanical variables possibly involved in an observed rearfoot motion or posture.

  8. On the mechanics of the ankle in the stance phase of the gait.

    PubMed

    Shamaei, Kamran; Cenciarini, Massimo; Dollar, Aaron M

    2011-01-01

    In this paper we explore the mechanical behavior of the ankle in the progression stage of stance during normal walking. We show that the torque/angle behavior of the ankle during this stage can be approximated by an augmented linear torsional spring. The mechanical parameters completely specifying this spring are identified, including stiffness, amount of rotation, and angle of zero moment. The effect of load weight, gait speed and ground slope on those parameters and the propulsive work of the ankle are also discussed. The findings of this paper can be applied to the design of leg orthoses, prostheses and exoskeletons, and bipedal robots in general, allowing the implementation of human-like leg compliance during stance with a relatively simple latched-spring mechanism.

  9. Segment and joint angles of hind limb during bipedal and quadrupedal walking of the bonobo (Pan paniscus).

    PubMed

    D'Août, Kristiaan; Aerts, Peter; De Clercq, Dirk; De Meester, Koen; Van Elsacker, Linda

    2002-09-01

    We describe segment angles (trunk, thigh, shank, and foot) and joint angles (hip, knee, and ankle) for the hind limbs of bonobos walking bipedally ("bent-hip bent-knee walking," 17 sequences) and quadrupedally (33 sequences). Data were based on video recordings (50 Hz) of nine subjects in a lateral view, walking at voluntary speed. The major differences between bipedal and quadrupedal walking are found in the trunk, thigh, and hip angles. During bipedal walking, the trunk is approximately 33-41 degrees more erect than during quadrupedal locomotion, although it is considerably more bent forward than in normal human locomotion. Moreover, during bipedal walking, the hip has a smaller range of motion (by 12 degrees ) and is more extended (by 20-35 degrees ) than during quadrupedal walking. In general, angle profiles in bonobos are much more variable than in humans. Intralimb phase relationships of subsequent joint angles show that hip-knee coordination is similar for bipedal and quadrupedal walking, and resembles the human pattern. The coordination between knee and ankle differs much more from the human pattern. Based on joint angles observed throughout stance phase and on the estimation of functional leg length, an efficient inverted pendulum mechanism is not expected in bonobos.

  10. Mechanical performance of artificial pneumatic muscles to power an ankle-foot orthosis.

    PubMed

    Gordon, Keith E; Sawicki, Gregory S; Ferris, Daniel P

    2006-01-01

    We developed a powered ankle-foot orthosis that uses artificial pneumatic muscles to produce active plantar flexor torque. The purpose of this study was to quantify the mechanical performance of the orthosis during human walking. Three subjects walked at a range of speeds wearing ankle-foot orthoses with either one or two artificial muscles working in parallel. The orthosis produced similar total peak plantar flexor torque and network across speeds independent of the number of muscles used. The orthosis generated approximately 57% of the peak ankle plantar flexor torque during stance and performed approximately 70% of the positive plantar flexor work done during normal walking. Artificial muscle bandwidth and force-length properties were the