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Sample records for quadriceps femoris influences

  1. The influence of isometric hip adduction on quadriceps femoris activity.

    PubMed

    Hodges, P W; Richardson, C A

    1993-06-01

    In the treatment of muscle imbalances around the knee, hip adduction and the contraction of adductor magnus have been used to facilitate vastus medialis obliquus (VMO) to a greater extent than vastus lateralis (VL). This study was conducted to investigate the effectiveness of this technique. Hip adduction was superimposed onto the contraction of quadriceps femoris in a weight bearing (WB) and a non-weight bearing (NWB) position at three levels of hip adduction force. The muscle activity of VMO and VL was recorded using electromyography with the ratio of the recordings of VMO to VL used for comparison. The activity of VMO compared with VL was greater in WB than NWB without hip adduction. VMO activity increased relatively more than VL with the addition of each level of hip adduction in WB and only with maximal hip adduction in NWB. The results provide support for the use of this technique.

  2. New aspects of the influence of quadriceps femoris muscle stimulation course on functional capabilities of the organism.

    PubMed

    Arkov, V V; Abramova, T F; Nikitina, T M; Afanasjeva, D A; Anosova, A A; Milenina, A I; Tonevitsky, A G

    2010-08-01

    We studied the effect of a course of electrical stimulation of the quadriceps femoris muscle with submaximal contraction under biofeedback conditions on functional capabilities of the organism. In addition to the known effects, electrostimulation course modulated the content of intra- and extracellular fluid and increases MDA content and creatine phosphokinase activity, which can be a manifestation of overtreatment. Impairment of body static balance after the course was revealed. Thus, monitoring of the effects of electrostimulation is required during the course.

  3. [Reconstruction of quadriceps femoris muscle function with muscle transfer].

    PubMed

    Fansa, H; Meric, C

    2010-08-01

    Femoral nerve palsy, mostly of iatrogen cause, leads to paresis of quadriceps muscle with complete loss of knee extension. Therapeutical options include neurolysis, nerve reconstruction or functional muscle transplantations. Another concept is the transfer of hamstring muscles as described in post polio surgery. We describe our experience of biceps femoris and semitendinosus muscle transfer for reconstruction of knee extension. From 2003 to 2007 seven patients (mean age 43) with complete loss of knee extension after femoral nerve lesion were treated. Nerve palsy was caused by direct lesion, traction, hematoma after collapse, lesion of lumbosacral plexus and an unclear muscle dystrophy. Indication for muscle transfer was due to long standing muscle paresis. All patients received a transfer of biceps femoris and semitendinosus muscle/tendon into the quadriceps tendon. Patients were immobilised in a cast for 6 weeks in extended knee position. Weight bearing started after 8 weeks. Operations went uneventfully. All patients were able to extend the knee postoperatively against gravity and were able to climb stairs without help. 4 Patients had complete knee extension, 2 had a lack of 20 degrees , one of 30 degrees. Daily routine was possible in all cases. No instability of knee joints occurred postoperatively. In a nerve lesion close to the muscle a nerve reconstruction should be aimed. If not performed or with unsuccessful outcome, muscle transfer is a good option to restore function. All recent studies describe good to excellent results with stable knees, allowing the patient to manage daily routine without assistance and to climb stairs up and down. Long term complications such as dislocation of patella or genu recurvatum were not observed in our patients. The latter results as typical complication in polio from weakening knee flexion through biceps femoris transfer, if the gastrocnemius muscle is not forceful enough. However in an isolated femoral nerve lesion this

  4. Optimal Burst Duration During a Facilitated Quadriceps Femoris Contraction

    PubMed Central

    McLoda, Todd A.; Carmack, Jennifer A.

    2000-01-01

    Objective: To determine the most efficient burst duty cycle for eliciting an involuntary quadriceps femoris contraction in healthy subjects. This information will allow clinicians to make an informed decision about the optimal burst duty cycle based upon a specific treatment goal. The logical goal for such a treatment choice is to enhance motor unit recruitment in an effort to maintain postoperative or postinjury strength, when voluntary contractions may be less effective. Design and Setting: Single-group and 5-measures design. All tests were performed in a university laboratory. Subjects: Forty-eight healthy subjects (27 men and 21 women; mean age, 26.4 ± 8.5 years) performed a maximal voluntary isometric contraction (MVIC) on an isokinetic device and received neuromuscular electrical stimulation (NMES) at 5 different burst duty cycles. Measurements: Subjects first performed an MVIC for knee extension on an isokinetic dynamometer at 60° of knee flexion. NMES surface electrodes were applied to the quadriceps muscle of each subject's dominant leg. The values for the NMES were 2500-Hz carrier frequency, 50-bursts-per-second treatment frequency, amplitude increased to maximum tolerance, and burst duty cycle set to each of the 5 comparison values. The peak isometric force generated by each of the 5 nonvolitional contractions was recorded, along with the maximal charge per burst tolerated by each subject. Force generated was described as percentage of MVIC. Efficiency was the amount of force per burst charge. Results: The mean MVIC achieved by the subjects was 553.8 newtons (N). The average force per burst charge generated at 10% burst duty cycle was 132.9 N; at 30%, 104.2 N; at 50%, 93.1 N; at 70%, 52.9 N; and at 90%, 41.3 N. The average efficiency (force per millicoulombs [mC]) at 10% burst duty cycle was the highest at 6.49 N/mC and at 90% was the lowest at 1.05 N/mC. Conclusions: A burst duty cycle of 10% was the most efficient ratio of burst duration to

  5. Continuous Femoral Nerve Blocks: Decreasing Local Anesthetic Concentration to Minimize Quadriceps Femoris Weakness

    PubMed Central

    Bauer, Maria; Wang, Lu; Onibonoje, Olusegun K.; Parrett, Chad; Sessler, Daniel I.; Mounir-Soliman, Loran; Zaky, Sherif; Krebs, Viktor; Buller, Leonard T.; Donohue, Michael C.; Stevens-Lapsley, Jennifer E.; Ilfeld, Brian M.

    2012-01-01

    Background Whether decreasing the local anesthetic concentration during a continuous femoral nerve block results in less quadriceps weakness remains unknown. Methods Preoperatively, bilateral femoral perineural catheters were inserted in patients undergoing bilateral knee arthroplasty (n = 36) at a single clinical center. Postoperatively, right-sided catheters were randomly assigned to receive perineural ropivacaine of either 0.1% (basal 12 mL/h; bolus 4 mL) or 0.4% (basal 3 mL/h; bolus 1 mL), with the left catheter receiving the alternative concentration/rate in an observer- and subject-masked fashion. The primary endpoint was the maximum voluntary isometric contraction of the quadriceps femoris muscles the morning of postoperative day 2. Equivalence of treatments would be concluded if the 95% confidence interval for the difference fell within the interval of −20% to 20%. Secondary endpoints included active knee extension, passive knee flexion, tolerance to cutaneous electrical current applied over the distal quadriceps tendon, dynamic pain scores, opioid requirements, and ropivacaine consumption. Results Quadriceps maximum voluntary isometric contraction for limbs receiving 0.1% ropivacaine was a mean (SD) of 13 (8) N·m, versus 12 (8) N·m for limbs receiving 0.4% [intra-subject difference of 3 (40) percentage points; 95% CI −10 to 17; p = 0.63]. Because the 95% confidence interval fell within prespecified tolerances, we conclude that the effect of the two concentrations were equivalent. Similarly, there were no statistically significant differences in secondary endpoints. Conclusions For continuous femoral nerve blocks, we found no evidence that local anesthetic concentration and volume influence block characteristics, suggesting that local anesthetic dose (mass) is the primary determinant of perineural infusion effects. PMID:22293719

  6. Inhomogeneous Quadriceps Femoris Hypertrophy in Response to Strength and Power Training.

    PubMed

    Earp, Jacob E; Newton, Robert U; Cormie, Prue; Blazevich, Anthony J

    2015-11-01

    Previous studies have reported inhomogeneous changes in quadriceps femoris (QF) cross-sectional area (CSA) in response to strength training. It is assumed that these differential changes in muscle shape influence the muscle's functional capacity during high-force and high-power movements. The purpose of the current study was to compare intermuscular and intramuscular QF adaptations to high-load strength training and fast-speed power training. Thirty-six non-strength-trained men were randomly assigned to four groups and completed 8 wk of parallel-depth heavy squat-lift training (HS-P), parallel-depth jump squat training (JS-P), volitional-depth jump squat training (JS-V), or no training (C). Quadriceps femoris, vastus lateralis (VL), intermedius (VI), medialis (VM), and rectus femoris (RF) CSA were measured in distal-, mid-, and proximal-thigh regions using extended field-of-view ultrasonography and compared using a 3 × 2 mixed-model MANOVA with Bonferroni post hoc tests (P < 0.05). Parallel-depth heavy squat-lift training and JS-P elicited similar changes in mid-CSA(QF) as well as summed CSA of the QF, VL, VI, and VM. Cross-sectional area of the VL (CSA(VL)) and CSA(VI) increased in both HS-P and JS-P at mid-thigh, but only JS-P significantly increased CSA proximally, and only HS-P significantly increased CSA distally. Cross-sectional area of the VM (CSA(VM)) increased in HS-P and JS-P distally, but only HS-P increased at mid-thigh. No hypertrophy was observed in RF at any location and no significant differences were observed between JS-P and JS-V. Parallel-depth heavy squat-lift training elicited greater proximal hypertrophy in each of the vasti muscles, whereas only JS-P elicited distal VL and VI hypertrophy. These observed inhomogeneous changes in CSA may alter the thigh's moment of inertia and moment arms of muscle "compartments," and the influence of elastic component force transmission on the muscular force expression. Such selective hypertrophy is

  7. Firing rate analysis using decompostion-enhanced spike triggered averaging in the quadriceps femoris.

    PubMed

    Conwit, R A; Tracy, B; Cowl, A; McHugh, M; Stashuk, D; Brown, W F; Metter, E J

    1998-10-01

    Electromyographic signals detected from the quadriceps femoris during various constant force contractions were decomposed to identify individual motor unit discharges and mean firing rates (FRs). Subject and group mean FRs were calculated for each force level. Mean FR values and FR variability increased with force. Individual, subject, and group mean FRs showed slight increases until 30% of maximum voluntary contraction and larger increases thereafter. Findings are discussed in relation to motor unit recruitment, frequency modulation, and fatigue.

  8. Hemipelvectomy for Buttock Tumors Utilizing an Anterior Myocutaneous Flap of Quadriceps Femoris Muscle

    PubMed Central

    Sugarbaker, Paul H.; Chretien, Paul A.

    1983-01-01

    Hemipelvectomy utilizing an anterior myocutaneous flap is indicated for aggressive tumors of the buttock and proximal portion of the posterior thigh. A large operative defect created posteriorly by amputation of the lower extremity, hemipelvis, and buttock is covered by a myocutaneous flap of quadriceps femoris muscle and overlying skin and subcutaneous tissue. The superficial femoral artery is preserved to sustain the myocutaneous flap. ImagesFig. 2A,B,C.Fig. 2A,B,C. PMID:6848048

  9. Changes in transverse relaxation time of quadriceps femoris muscles after active recovery exercises with different intensities.

    PubMed

    Mukaimoto, Takahiro; Semba, Syun; Inoue, Yosuke; Ohno, Makoto

    2014-01-01

    The purpose of this study was to examine the changes in the metabolic state of quadriceps femoris muscles using transverse relaxation time (T2), measured by muscle functional magnetic resonance (MR) imaging, after inactive or active recovery exercises with different intensities following high-intensity knee-extension exercise. Eight healthy men performed recovery sessions with four different conditions for 20 min after high-intensity knee-extension exercise on separate days. During the recovery session, the participants conducted a light cycle exercise for 20 min using a cycle (50%, 70% and 100% of the lactate threshold (LT), respectively: active recovery), and inactive recovery. The MR images of quadriceps femoris muscles were taken before the trial and after the recovery session every 30 min for 120 min. The percentage changes in T2 for the rectus femoris and vastus medialis muscles after the recovery session in 50% LT and 70% LT were significantly lower than those in either inactive recovery or 100% LT. There were no significant differences in those for vastus lateralis and vastus intermedius muscles among the four trials. The percentage changes in T2 of rectus femoris and vastus medialis muscles after the recovery session in 50% LT and 70% LT decreased to the values before the trial faster than those in either inactive recovery or 100% LT. Those of vastus lateralis and vastus intermedius muscles after the recovery session in 50% LT and 70% LT decreased to the values before the trial faster than those in 100% LT. Although the changes in T2 after active recovery exercises were not uniform in exercised muscles, the results of this study suggest that active recovery exercise with the intensities below LT are more effective to recover the metabolic state of quadriceps femoris muscles after intense exercise than with either intensity at LT or inactive recovery.

  10. Evaluation of Electromyographic Biofeedback for the Quadriceps Femoris: A Systematic Review

    PubMed Central

    Wasielewski, Noah J.; Parker, Tonya M.; Kotsko, Kevin M.

    2011-01-01

    Objective: To critically review evidence for the effectiveness of electromyographic biofeedback (EMGB) of the quadriceps femoris muscle in treating various knee conditions. Data Sources: Databases used to locate randomized controlled trials included PubMed (1980–2010), Cumulative Index of Nursing and Allied Health Literature (CINAHL, 1995–2007), Web of Science (1986–2010), SPORTDiscus (1990–2007), and Physiotherapy Evidence Database (PEDro). Key words were knee and biofeedback. Study Selection: The criteria for selection were clinical randomized controlled trials in which EMGB of the quadriceps femoris was used for various knee conditions of musculoskeletal origin. Trials were excluded because of research designs other than randomized controlled trials, articles published in a non-English language, inclusion of healthy research participants, inability to identify EMGB as the source of clinical improvement, and lack of pain, functional outcome, or quadriceps torque as outcome measures. Data Extraction: Twenty specific data points were abstracted from each clinical trial under the broad categories of attributes of the patient and injury, treatment variables for the EMGB group, treatment variables for the control group, and attributes of the research design. Data Synthesis: Eight trials yielded a total of 319 participants with patellofemoral pain syndrome (n = 86), anterior cruciate ligament reconstruction (n = 52), arthroscopic surgery (n = 91), or osteoarthritis (n = 90). The average methodologic score of the included studies was 4.6/10 based on PEDro criteria. Pooled analyses demonstrated heterogeneity of the included studies, rendering the interpretation of the pooled data inappropriate. The EMGB appeared to benefit short-term postsurgical pain or quadriceps strength in 3 of 4 postsurgical investigations but was ineffective for chronic knee conditions such as patellofemoral pain and osteoarthritis in all 4 studies. Because the findings are based on limited

  11. Measurement of the quadriceps femoris muscle using magnetic resonance and ultrasound imaging.

    PubMed Central

    Walton, J M; Roberts, N; Whitehouse, G H

    1997-01-01

    OBJECTIVES: To define a method for measurement of the cross sectional area and volume of the quadriceps femoris muscle using magnetic resonance imaging (MRI) in conjunction with stereology, and to compare the results of measurements obtained by the MRI method with those obtained by the conventional method of static B-mode ultrasound in order to evaluate whether MRI is a reliable alternative to ultrasound. METHODS: A preliminary MRI study was undertaken on a single female volunteer in order to optimise the scanning technique and sampling design for estimating the muscle volume using the Cavalieri method. Ten healthy volunteers participated in the method comparison study. Each volunteer underwent static B-mode ultrasonography, immediately followed by MRI. The cross sectional area of the quadriceps femoris was estimated at the junction of the proximal one third and distal two thirds of the thigh, and seven systematic sections of the thigh were obtained in order to estimate muscle volume by both modalities. RESULTS: Seven sections through the muscle are required to achieve a coefficient of error of 4-5%. There was no significant difference in the cross sectional area estimates or volume estimates when ultrasound and MRI were compared. CONCLUSION: Muscle cross sectional area and volume can be measured without bias by MRI in conjunction with stereological methods and the method is a reliable alternative to static B-mode ultrasound for this purpose. Images Figure 1 Figure 4 Figure 5 PMID:9132215

  12. Intra- and intermuscular variation in human quadriceps femoris architecture assessed in vivo

    PubMed Central

    Blazevich, Anthony J; Gill, Nicholas D; Zhou, Shi

    2006-01-01

    Despite the functional importance of the human quadriceps femoris in movements such as running, jumping, lifting and climbing, and the known effects of muscle architecture on muscle function, no research has fully described the complex architecture of this muscle group. We used ultrasound imaging techniques to measure muscle thickness, fascicle angle and fascicle length at multiple regions of the four quadriceps muscles in vivo in 31 recreationally active, but non-strength-trained adult men and women. Our analyses revealed a reasonable similarity in the superficial quadriceps muscles, which is suggestive of functional similarity (at least during the uni-joint knee extension task) given that they act via a common tendon. The deep vastus intermedius (VI) is architecturally dissimilar and therefore probably serves a different function(s). Architecture varies significantly along the length of the superficial muscles, which has implications for the accuracy of models that assume a constant intramuscular architecture. It might also have consequences for the efficiency of intra- and intermuscular force transmission. Our results provide some evidence that subjects with a given architecture of one superficial muscle, relative to the rest of the subject sample, also have a similar architecture in other superficial muscles. However, this is not necessarily true for vastus lateralis (VL), and was not the case for VI. Therefore, the relative architecture of one muscle cannot confidently be used to estimate the relative architecture of another. To confirm this, we calculated a value of whole quadriceps architecture by four different methods. Regardless of the method used, we found that the absolute or relative architecture of one muscle could not be used as an indicator of whole quadriceps architecture, although vastus medialis, possibly in concert with VL and the anterior portion of VI, could be used to provide a useful snapshot. Importantly, our estimates of whole quadriceps

  13. The effect of quadriceps femoris muscle Kinesio Taping on physical fitness indices in non-injured athletes.

    PubMed

    Mostaghim, Nasim; Jahromi, Maryam K; Shirazzi, Zahra R; Salesi, Mohsen

    2016-12-01

    Evaluating the effect of kinesio taping of quadriceps femoris muscle on some physical fitness indices including maximal voluntary isometric contraction (MVIC), vertical jump, agility and sprint in healthy collegiate athletes. Forty-four (23 male and 21 female) healthy collegiate athletes voluntarily participated in this study. The MVIC of quadriceps muscle (N) of the dominant leg was assessed by digital Dynamometer. vertical jump, agility and sprint was assessed using Sargent vertical jump, shuttle run agility and 30-yard sprint tests, respectively. All measures were obtained in 4 trails: control (without taping), two trials with 24 hours interval, immediately and 24 hours after tape application. Two conditions of with and without taping measures were performed by one week interval. Everybody was compared to themselves during different situations. Data was analyzed using SPSS software and ANOVA with repeated measure statistical test. MVIC, jumping and sprint performance significantly improved immediately and 24 hours following KT application compared to non KT conditions (P<0.05). Agility was improved 24 hours following taping (P<0.05), but KT caused no significant immediate effect on agility (P>0.05). 24 hours KT caused significant improvement in MVIC, jumping and agility performance, but caused no significant effect on sprint compared to immediately following taping. KT influenced positively MVIC, jumping, agility and sprint and the major effect was achieved by maintaining KT for 24hours in healthy athletes. Although, regarding the study limitations, future studies are recommended for clarification.

  14. Isokinetic eccentric exercise of quadriceps femoris does not affect running economy.

    PubMed

    Vassilis, Paschalis; Vassilios, Baltzopoulos; Vassilis, Mougios; Athanasios, Jamurtas Z; Vassilis, Theoharis; Christina, Karatzaferi; Yiannis, Koutedakis

    2008-07-01

    The purpose of this study was to investigate whether running economy is affected by isokinetic eccentric exercise designed to cause muscle damage. Twenty-four young healthy men performed 120 maximal voluntary eccentric actions at each thigh's quadriceps muscle at an angular velocity of 60 degrees .s. The participants were then randomly divided into 2 equal groups, 1 of which exercised 24 hours later, while the other group rested. Muscle damage indicators (i.e., serum creatine kinase, delayed onset muscle soreness, and eccentric, concentric, and isometric peak torque) and running economy indicators (i.e., oxygen consumption, pulmonary ventilation, respiratory exchange ratio, respiratory rate, and heart rate during treadmill running at 2.2 and 3.3 m.s) were assessed prior to and 48 hours following the eccentric exercise. All muscle damage indicators changed significantly in both groups (p < 0.05) in a way suggestive of considerable muscle damage. Running economy indicators of the exercise group demonstrated only an elevation of respiratory rate at 48 hours (p < 0.05) and a tendency to lower economy compared to the resting group. It can be concluded that isokinetic eccentric exercise applied to the quadriceps femoris muscles did not affect running economy 48 hours later and that resting during this period tended to result in more economical running compared to exercising at 24 hours.

  15. Manual segmentation of individual muscles of the quadriceps femoris using MRI: a reappraisal.

    PubMed

    Barnouin, Yoann; Butler-Browne, Gillian; Voit, Thomas; Reversat, David; Azzabou, Noura; Leroux, Gaëlle; Behin, Anthony; McPhee, Jamie S; Carlier, Pierre G; Hogrel, Jean-Yves

    2014-07-01

    To propose a manual segmentation method for individual quadriceps femoris (QF) muscles and to test its reliability for muscle volume estimation. Images were acquired every 5 mm along the thigh using a 3T MRI scanner on 10 young (mean age: 25 years) and 10 older (mean age: 75 years) adults using a three-point 3D Dixon sequence. In each slice, anatomical cross-sectional areas of the individual quadriceps muscles of the dominant leg were outlined by two operators working independently. Differences between operators were assessed by means of Bland-Altman plots and intraclass correlation coefficients (ICC). This study was approved by the local Ethics Committee. Precise delimitation of individual muscles along the femur often remains challenging, particularly near their insertion areas where some muscles may be partially or totally fused. There was, however, an excellent interoperator segmentation reliability despite a systematic significant difference between operators (ICC > 0.99), mainly due to delineation divergences. Considering all subjects and muscles, differences between operators were all lower than 4.4%. This work has demonstrated the excellent reliability of manual segmentation to assess cross-sectional areas and therefore the volume of individual QF muscles using MRI. It may serve as a basis for a future segmentation consensus of the QF muscles. © 2013 Wiley Periodicals, Inc.

  16. Angle- and gender-specific quadriceps femoris muscle recruitment and knee extensor torque.

    PubMed

    Pincivero, Danny M; Salfetnikov, Yuliya; Campy, Robert M; Coelho, Alan J

    2004-11-01

    The objectives were to examine knee angle-, and gender-specific knee extensor torque output and quadriceps femoris (QF) muscle recruitment during maximal effort, voluntary contractions. Fourteen young adult men and 15 young adult women performed three isometric maximal voluntary contractions (MVC), in a random order, with the knee at 0 degrees (terminal extension), 10 degrees, 30 degrees, 50 degrees, 70 degrees, and 90 degrees flexion. Knee extensor peak torque (PT), and average torque (AT) were expressed in absolute (N m), relative (N m kg(-1)) and allometric-modeled (N m kg(-n)) units. Vastus medialis (VM), vastus lateralis (VL), and rectus femoris (RF) muscle EMG signals were full-wave rectified and integrated over the middle 3 s of each contraction, averaged over the three trials at each knee angle, and normalized to the activity recorded at 0 degrees. Muscle recruitment efficiency was calculated as the ratio of the normalized EMG of each muscle to the allometric-modeled average torque (normalized to the values at 0 degrees flexion), and expressed as a percent. Men generated significantly greater knee extensor PT and AT than women in absolute, relative and allometric-modeled units. Absolute and relative PT and AT were significantly highest at 70 degrees, while allometric-modeled values were observed to increase significantly across knee joint angles 10-90 degrees. VM EMG was significantly greater than the VL and RF muscles across all angles, and followed a similar pattern to absolute knee extensor torque. Recruitment efficiency improved across knee joint angles 10-90 degrees and was highest for the VL muscle. VM recruitment efficiency improved more than the VL and RF muscles across 70-90 degrees flexion. The findings demonstrate angle-, and gender-specific responses of knee extensor torque to maximal-effort contractions, while superficial QF muscle recruitment was most efficient at 90 degrees, and less dependent on gender.

  17. Activation of quadriceps femoris including vastus intermedius during fatiguing dynamic knee extensions.

    PubMed

    Akima, Hiroshi; Saito, Akira

    2013-11-01

    Fatigue-related muscle activity in the superficial quadriceps femoris (QF) muscles has been widely examined; however, there is no information on the activity of the deep vastus intermedius (VI) muscle during fatiguing dynamic knee extensions. The purpose of this study was to investigate neuromuscular activation patterns of the QF synergists, including the VI, during fatiguing dynamic knee extensions at two submaximal loads. Nine healthy men performed dynamic knee extensions with loads of 50 and 70 % of one-repetition maximum (1RM) until failure. Muscle activation of the VI, vastus lateralis, vastus medialis (VM) and rectus femoris was recorded using surface electrodes. Root mean square (RMS) amplitude was calculated during the concentric (CON) and eccentric (ECC) phases of each repetition, and normalized to the RMS amplitude during the CON and ECC phases of the 1RM. Each CON and ECC phase was further divided into three subphases according to knee joint angle. The normalized RMS amplitude of the four individual QF muscles during the CON phase linearly increased with fatigue with contractions at both 50 and 70 % 1RM. The highest RMS amplitude was found in VI at flexed knee joint angles until fatigue. This activation pattern was more prominent at 70 % 1RM than 50 % 1RM. The RMS amplitude of VM at extended knee joint angles was selectively higher at 70 % 1RM than 50 % 1RM. These results suggest that the contribution of the four individual QF muscles to fatiguing dynamic knee extensions differs according to knee joint angle and intensity of load.

  18. Quadriceps femoris electromyogram during concentric, isometric and eccentric phases of fatiguing dynamic knee extensions.

    PubMed

    Pincivero, Danny M; Gandhi, Varsha; Timmons, Mark K; Coelho, Alan J

    2006-01-01

    The objective of this study was to examine the superficial quadriceps femoris (QF) muscle electromyogram (EMG) during fatiguing knee extensions. Thirty young adults were evaluated for their one-repetition maximum (1RM) during a seated, right-leg, inertial knee extension. All subjects then completed a single set of repeated knee extensions at 50% 1RM, to failure. Subjects performed a knee extension (concentric phase), held the weight with the knee extended for 2s (isometric phase), and lowered the weight in a controlled manner (eccentric phase). Raw EMG of the vastus medialis (VM), vastus lateralis (VL) and rectus femoris (RF) muscles were full-wave rectified, integrated and normalized to the 1RM EMG, for each respective phase and repetition. The EMG median frequency (f(med)) was computed during the isometric phase. An increase in QF muscle EMG was observed during the concentric phase across the exercise duration. VL EMG was greater than the VM and RF muscles during the isometric phase, in which no significant changes occurred in any of the muscles across the exercise duration. A significant decrease in EMG across the exercise duration was observed during the eccentric phase, with the VL EMG greater than the VM and RF muscles. A greater decrease in VL and RF muscle f(med) during the isometric phase, than the VM muscle, was observed with no gender differences. The findings demonstrated differential recruitment of the superficial QF muscle, depending on the contraction mode during dynamic knee extension exercise, where VL muscle dominance appears to manifest across the concentric-isometric-eccentric transition.

  19. Assessment of the Quadriceps Femoris Muscle in Women after Injury Induced by Maximal Eccentric Isokinetic Exercise with Low Angular Speed

    PubMed Central

    Serráo, Fábio Viadanna; Serráo, Paula Regina Mendes da Silva; Foerster, Bernd; Tannús, Alberto; Monteiro Pedro, Vanessa; Salvini, Tania F.

    2007-01-01

    The objectives of this study were to propose a model for exercise- induced muscle injury by way of a maximal eccentric isokinetic exercise at low angular speed, and assess the time course of functional recovery of the injured quadriceps femoris muscle from the maximal voluntary contraction (MVC) torque and electrical activity (root mean square - RMS and median frequency - MDF). The effectiveness of the proposed eccentric exercise in inducing injury was assessed from the activity of creatine kinase (CK). In addition, the presence of edema of the quadriceps femoris muscle was assessed by a visual inspection of the intensity of the magnetic resonance imaging (MRI) signal. These measurements were carried out before and after the exercise. Ten healthy women (21.9 ± 1.5) took part in this study. The injury was induced by 4 series of 15 maximal eccentric isokinetic contractions at 5°/s. The MVC torque reduced up to the 4th day after the exercise (p < 0.05). The RMS of the vastus medialis oblique (VMO) and the rectus femoris (RF) muscles decreased on the 2nd (VMO and RF; p < 0.05) and 3rd (RF; p < 0.05) days after. The MDF of the VMO increased immediately after (p < 0.05), whilst the MDF of the RF and VL decreased immediately after (RF; p < 0.05), on the 1st (RF and VL; p < 0.05) and on the 2nd (VL; p < 0.05) days after. The CK activity increased on the 2nd day after (p < 0.05). An increase in the intensity of the MRI signal was observed on the 2nd and 7th days after. In conclusion: 1- the eccentric exercise with low angular speed was effective in inducing injury, 2- the quadriceps femoris already started its functional recovery, as shown by the MVC torque and electrical activity, in the first week after the exercise, despite the presence of an increase in the intensity of the MRI signal. Key pointsThe low angular speed eccentric exercise was effec-tive in inducing injury of the quadriceps femoris muscle, and could be used as a muscle injury induc-ing model in future

  20. An examination of cross-talk among surface mechanomyographic signals from the superficial quadriceps femoris muscles during isometric muscle actions.

    PubMed

    Beck, Travis W; DeFreitas, Jason M; Stock, Matt S

    2010-04-01

    The purpose of this study was to examine cross-talk among the mechanomyographic (MMG) signals from the superficial quadriceps femoris muscles during submaximal to maximal isometric muscle actions of the leg extensors. Eleven healthy men (age=20.1+/-1.1yr, mean+/-SD) volunteered to randomly perform isometric muscle actions in 10% increments from 10% to 90% of the maximum voluntary contraction (MVC). During each muscle action, MMG signals were detected from the vastus lateralis, rectus femoris, and vastus medialis with three separate accelerometers. Cross-correlation was used to quantify cross-talk among the vastus lateralis, rectus femoris, and vastus medialis during each muscle action. The results showed cross-correlation coefficients that ranged from R(x,y)=.124-.714, but generally speaking, the coefficients were between .1 and .3. In addition, there were no consistent differences among the cross-talk levels for the three muscles, and the cross-correlation coefficients generally did not increase with isometric torque. Thus, MMG can be used to examine muscle function from each of the superficial quadriceps femoris muscles during isometric muscle actions.

  1. Relationship between quadriceps femoris muscle volume and muscle torque after anterior cruciate ligament rupture.

    PubMed

    Konishi, Yu; Oda, Toshiaki; Tsukazaki, Satoshi; Kinugasa, Ryuta; Hirose, Norikazu; Fukubayashi, Toru

    2011-04-01

    The purpose of this study was to obtain evidence to support the hypothesis that motor unit recruitment is reduced in the quadriceps femoris (QF) of patients with ACL rupture. We compared muscle torque per unit volume in the QF from injured and uninjured sides to normal subjects. If high-threshold motor unit recruitment is reduced in patients with ACL rupture, this reduction will theoretically lead to a reduction in muscle torque per unit volume compared to the control group. The subjects included 22 patients with ACL rupture and 22 subjects with no history of knee injury. To identify the muscle torque per unit volume, the isokinetic peak torque was divided by QF volume which was obtained by MRI. Tests revealed that the mean muscle torque per unit volume of the uninjured and injured sides was significantly lower than those of the control group. This study demonstrated that the values of the muscle torque per unit volume of both injured and uninjured sides of patients with ACL rupture were significantly lower than those of the control group, thereby providing indirect evidence of the hindrance of motor unit recruitment in these patients. The results of the present study also indicate that there may be bilateral QF weakness in patients with ACL rupture. Since persistent QF weakness is a significant barrier to effective rehabilitation in patients with ACL injuries, a better understanding of the underlying mechanisms will allow clinicians and scientists to develop more effective therapeutic strategies for patient rehabilitation.

  2. Effects of prolonged patellar tendon vibration on force steadiness in quadriceps femoris during force-matching task.

    PubMed

    Saito, Akira; Ando, Ryosuke; Akima, Hiroshi

    2016-01-01

    The quadriceps femoris (QF) muscle group plays an essential role in human movement, such as standing, walking and running. The ability to maintain a steady force during physical activity of the human lower limb is important for mobility, postural control and balance. Although prolonged mechanical vibration of the muscle-tendon unit can moderate the efficacy of synaptic input from Ia afferent onto the α-motor neuron pathway, the effect of prolonged tendon vibration on fluctuations of knee extensor force has received little attention. The purpose of the present study was to examine the effects of prolonged patellar tendon vibration on the force steadiness of the QF muscle. Nine healthy men performed a submaximal force-matching task involving isometric knee extension before and after patellar tendon vibration or quiet seated rest (n = 7, control condition) for 30 min. The target force was 2.5, 10 and 30 % of maximal voluntary contraction (MVC). Surface electromyography (EMG) of the four QF synergists was recorded and normalized to EMG amplitude during the MVC. The knee extension force and the EMG amplitude of vastus medialis during the MVC were significantly reduced after the vibration, but did not significantly decrease in the control condition. Fluctuations of force and normalized EMG of individual QF muscles at each submaximal force level did not significantly change after the vibration. We conclude that prolonged patellar tendon vibration does not influence the force steadiness of the QF muscle during an isometric force-matching task.

  3. Analysis of three different equations for predicting quadriceps femoris muscle strength in patients with COPD *

    PubMed Central

    Nellessen, Aline Gonçalves; Donária, Leila; Hernandes, Nidia Aparecida; Pitta, Fabio

    2015-01-01

    Abstract Objective: To compare equations for predicting peak quadriceps femoris (QF) muscle force; to determine the agreement among the equations in identifying QF muscle weakness in COPD patients; and to assess the differences in characteristics among the groups of patients classified as having or not having QF muscle weakness by each equation. Methods: Fifty-six COPD patients underwent assessment of peak QF muscle force by dynamometry (maximal voluntary isometric contraction of knee extension). Predicted values were calculated with three equations: an age-height-weight-gender equation (Eq-AHWG); an age-weight-gender equation (Eq-AWG); and an age-fat-free mass-gender equation (Eq-AFFMG). Results: Comparison of the percentage of predicted values obtained with the three equations showed that the Eq-AHWG gave higher values than did the Eq-AWG and Eq-AFFMG, with no difference between the last two. The Eq-AHWG showed moderate agreement with the Eq-AWG and Eq-AFFMG, whereas the last two also showed moderate, albeit lower, agreement with each other. In the sample as a whole, QF muscle weakness (< 80% of predicted) was identified by the Eq-AHWG, Eq-AWG, and Eq-AFFMG in 59%, 68%, and 70% of the patients, respectively (p > 0.05). Age, fat-free mass, and body mass index are characteristics that differentiate between patients with and without QF muscle weakness. Conclusions: The three equations were statistically equivalent in classifying COPD patients as having or not having QF muscle weakness. However, the Eq-AHWG gave higher peak force values than did the Eq-AWG and the Eq-AFFMG, as well as showing greater agreement with the other equations. PMID:26398750

  4. Force-generating capacities and fatigability of the quadriceps femoris in relation to different exercise modes.

    PubMed

    Ullrich, Boris; Brüggemann, Gert-Peter

    2008-09-01

    In this study, we examined whether different exercise modes provoke functional differences in maximal and explosive force-generating capacities and fatigability of the quadriceps femoris (QF). Additionally, the interaction of different functional capacities was studied in competitive athletes. Ten competitive tennis players and 10 endurance athletes participated in the study. Pre-exercise force-generating capacities were determined during maximal voluntary isometric knee extensions (MVC). Fatigability of the QF was studied using sustained isometric contractions with target loads of 20% and 40% of pre-exercise MVC. Postexercise MVCs were conducted 20 seconds, 1 minute, and 3 minutes post task failure. Muscle activation of the QF during the fatiguing exercises and postexercise MVCs was estimated using surface electromyography. Higher explosive force-generating capacities, but no differences in absolute moments, were detected in tennis players compared with endurance athletes. Fatigability of the QF during both fatiguing tasks was approximately the same in both athletic populations. This was indicated by minor group differences in endurance time, postexercise MVC production, and electromyography (EMG)-estimated muscle activation during fatigue. Variability in endurance time was not significantly associated with pre-exercise force-generating capacities in these competitive athletes. In both athletic populations, recovery of MVC was significantly slower after the fatiguing contraction with 20% of MVC compared with that with 40% of MVC. These results may enhance understanding of plasticity of the neuromuscular system and yield interesting information for the optimization of athletic training programs. Explosive strength training might enhance endurance athletes' explosiveness without decreasing muscle fatigue resistance. The exercise profile of competitive tennis is suggested to act as a sufficient trigger to reach high neuromuscular fatigue resistance but may be

  5. Comparison of EMG activity between maximal manual muscle testing and cybex maximal isometric testing of the quadriceps femoris.

    PubMed

    Lin, Hui-Ting; Hsu, Ar-Tyan; Chang, Jia-Hao; Chien, Chi-Sheng; Chang, Guan-Liang

    2008-02-01

    Two methods have been used to produce a maximal voluntary isometric contraction (MVIC) of the superficial quadriceps femoris muscles for normalization of electromyographic (EMG) data. The purposes of this study were to compare the myoelectic activity of MVIC of manual muscle testing (MMT) versus Cybex maximal isometric testing. Eighteen normal subjects were recruited. MMT and Cybex testing for MVIC of the dominant leg were performed. EMG activities of the vastus medialis, vastus lateralis and rectus femoris were recorded during MMT and Cybex trials. EMG amplitude and median frequency obtained from the two methods (MMT and Cybex testing) were used for statistical analysis of these three muscles. Statistically, the difference in the mean of the EMG signal amplitude and median frequency between MMT and Cybex testing were not significant. Considering cost and time, MMT for MVIC technique appears to be reliable and highly valuable.

  6. Resting and active motor thresholds versus stimulus–response curves to determine transcranial magnetic stimulation intensity in quadriceps femoris

    PubMed Central

    2014-01-01

    Background Transcranial magnetic stimulation (TMS) is a widely-used investigative technique in motor cortical evaluation. Recently, there has been a surge in TMS studies evaluating lower-limb fatigue. TMS intensity of 120-130% resting motor threshold (RMT) and 120% active motor threshold (AMT) and TMS intensity determined using stimulus–response curves during muscular contraction have been used in these studies. With the expansion of fatigue research in locomotion, the quadriceps femoris is increasingly of interest. It is important to select a stimulus intensity appropriate to evaluate the variables, including voluntary activation, being measured in this functionally important muscle group. This study assessed whether selected quadriceps TMS stimulus intensity determined by frequently employed methods is similar between methods and muscles. Methods Stimulus intensity in vastus lateralis, rectus femoris and vastus medialis muscles was determined by RMT, AMT (i.e. during brief voluntary contractions at 10% maximal voluntary force, MVC) and maximal motor-evoked potential (MEP) amplitude from stimulus–response curves during brief voluntary contractions at 10, 20 and 50% MVC at different stimulus intensities. Results Stimulus intensity determined from a 10% MVC stimulus–response curve and at 120 and 130% RMT was higher than stimulus intensity at 120% AMT (lowest) and from a 50% MVC stimulus–response curve (p < 0.05). Stimulus intensity from a 20% MVC stimulus–response curve was similar to 120% RMT and 50% MVC stimulus–response curve. Mean stimulus intensity for stimulus–response curves at 10, 20 and 50% MVC corresponded to approximately 135, 115 and 100% RMT and 180, 155 and 130% AMT, respectively. Selected stimulus intensity was similar between muscles for all methods (p > 0.05). Conclusions Similar optimal stimulus intensity and maximal MEP amplitudes at 20 and 50% MVC and the minimal risk of residual fatigue at 20% MVC suggest that a 20% MVC

  7. Effect of eccentric exercise with reduced muscle glycogen on plasma interleukin-6 and neuromuscular responses of musculus quadriceps femoris.

    PubMed

    Gavin, James P; Myers, Stephen D; Willems, Mark E T

    2016-07-01

    Eccentric exercise can result in muscle damage and interleukin-6 (IL-6) secretion. Glycogen availability is a potent stimulator of IL-6 secretion. We examined effects of eccentric exercise in a low-glycogen state on neuromuscular function and plasma IL-6 secretion. Twelve active men (23 ± 4 yr, 179 ± 5 cm, 77 ± 10 kg, means ± SD) completed two downhill treadmill runs (gradient, -12%, 5 × 8 min; speed, 12.1 ± 1.1 km/h) with normal (NG) and reduced muscle glycogen (RG) in randomized order and at least 6 wk apart. Muscle glycogen was reduced using an established cycling protocol until exhaustion and dietary manipulation the evening before the morning run. Physiological responses were measured up to 48 h after the downhill runs. During recovery, force deficits of musculus quadriceps femoris by maximal isometric contractions were similar. Changes in low-frequency fatigue were larger with RG. Voluntary activation and plasma IL-6 levels were similar in recovery between conditions. It is concluded that unaccustomed, damaging eccentric exercise with low muscle glycogen of the m. quadriceps femoris 1) exacerbated low-frequency fatigue but 2) had no additional effect on IL-6 secretion. Neuromuscular impairment after eccentric exercise with low muscle glycogen appears to have a greater peripheral component in early recovery.

  8. Volume measurements of individual muscles in human quadriceps femoris using atlas-based segmentation approaches.

    PubMed

    Le Troter, Arnaud; Fouré, Alexandre; Guye, Maxime; Confort-Gouny, Sylviane; Mattei, Jean-Pierre; Gondin, Julien; Salort-Campana, Emmanuelle; Bendahan, David

    2016-04-01

    Atlas-based segmentation is a powerful method for automatic structural segmentation of several sub-structures in many organs. However, such an approach has been very scarcely used in the context of muscle segmentation, and so far no study has assessed such a method for the automatic delineation of individual muscles of the quadriceps femoris (QF). In the present study, we have evaluated a fully automated multi-atlas method and a semi-automated single-atlas method for the segmentation and volume quantification of the four muscles of the QF and for the QF as a whole. The study was conducted in 32 young healthy males, using high-resolution magnetic resonance images (MRI) of the thigh. The multi-atlas-based segmentation method was conducted in 25 subjects. Different non-linear registration approaches based on free-form deformable (FFD) and symmetric diffeomorphic normalization algorithms (SyN) were assessed. Optimal parameters of two fusion methods, i.e., STAPLE and STEPS, were determined on the basis of the highest Dice similarity index (DSI) considering manual segmentation (MSeg) as the ground truth. Validation and reproducibility of this pipeline were determined using another MRI dataset recorded in seven healthy male subjects on the basis of additional metrics such as the muscle volume similarity values, intraclass coefficient, and coefficient of variation. Both non-linear registration methods (FFD and SyN) were also evaluated as part of a single-atlas strategy in order to assess longitudinal muscle volume measurements. The multi- and the single-atlas approaches were compared for the segmentation and the volume quantification of the four muscles of the QF and for the QF as a whole. Considering each muscle of the QF, the DSI of the multi-atlas-based approach was high 0.87 ± 0.11 and the best results were obtained with the combination of two deformation fields resulting from the SyN registration method and the STEPS fusion algorithm. The optimal variables for FFD

  9. Effects of combined application of progressive resistance training and Russian electrical stimulation on quadriceps femoris muscle strength in elderly women with knee osteoarthritis.

    PubMed

    Park, Seong Hoon; Hwangbo, Gak

    2015-03-01

    [Purpose] The aim of this study was to investigate the effects of combined application of progressive resistance training and Russian electrical stimulation on quadriceps femoris muscle strength in elderly women with osteoarthritis of the knee. [Subjects] Thirty women over 65 years of age diagnosed with knee osteoarthritis participated in the present study. The subjects were randomly assigned to a control group (n=10), a progressive resistance training group (n=10), or a Russian electrical stimulation group (n=10). [Methods] Each group was treated 3 times weekly for 8 weeks, and each session lasted 45 minutes. Muscle strength was assessed by measuring the peak torque of the quadriceps femoris muscle. Outcome measurements were performed at baseline and at the fourth and eighth weeks of the treatment period. [Results] All groups showed significant intragroup differences in the quadriceps femoris muscle peak torque after the treatment intervention. There were significant intergroup differences between the Russian electrical stimulation group and the other groups. [Conclusion] The results of this study suggest that combined application of progressive resistance training and Russian electrical stimulation can be effective in strengthening the quadriceps femoris muscle in elderly women with knee osteoarthritis.

  10. Reproducibility of ultrasound-derived muscle thickness and echo-intensity for the entire quadriceps femoris muscle.

    PubMed

    Santos, R; Armada-da-Silva, P A S

    2017-08-01

    Muscle thickness (MT) and muscle echo-intensity (EI) allow the study of skeletal muscle adaptive changes with ultrasound. This study investigates the intra- and inter-session reliability and agreement of MT and EI measurements for each of the four heads of the quadriceps femoris in transverse and longitudinal scans, using two sizes for the region of interest (ROI); EI measurements only. Three B-mode images from two views were acquired from each head of quadriceps femoris from twenty participants (10 females) in two sessions, 7 days apart. EI was measured using a large and a small ROI. Reliability was examined with the mixed two-way intra-class correlation coefficient (ICC), the standard error of mean (SEM) and the smallest detectable change (SDC). Bland-Altman's plots were used to study agreement. High to very high inter-session ICC values were found for MT for all muscle heads, particularly for measurements from transverse scans. For EI measurement, ICC values ranged from low to high, with higher ICC values seen with the largest ROI. SDC values ranged between 0.19 and 0.53 cm for MT and between 3.73 and 18.56 arbitrary units (a.u.) for two ROIs. Good agreement existed between MT measurements made in both scans. A small bias and larger 95% limits of agreement were seen for EI measurements collected with the two ROI sizes. Ultrasound measures of MT and EI show moderate to very high reliability. The reliability and agreement of MT and EI measurements are improved in transverse scans and with larger ROIs. Copyright © 2017 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.

  11. Linearity and reliability of the mechanomyographic amplitude versus dynamic torque relationships for the superficial quadriceps femoris muscles.

    PubMed

    Stock, Matthew S; Beck, Travis W; Defreitas, Jason M; Dillon, Michael A

    2010-03-01

    The purpose of this investigation was to examine the linearity and reliability of the mechanomyographic (MMG) amplitude versus dynamic torque relationships for the vastus lateralis (VL), rectus femoris (RF), and vastus medialis (VM) muscles. Nine healthy men and 11 healthy women performed submaximal to maximal, concentric, isokinetic muscle actions of the leg extensors at 30 degrees s(-1) on two occasions. Surface MMG signals were detected from the VL, RF, and VM of the dominant thigh during both trials. The ranges of the coefficients of determination for the MMG amplitude versus dynamic torque relationships were 0.01-0.94 for the VL, 0.01-0.84 for the RF, and 0.19-0.96 for the VM. The intraclass correlation coefficients for the linear MMG amplitude versus torque slope coefficients were 0.823 (VL), 0.792 (RF), and 0.927 (VM). These results indicate that, when analyzed for individual subjects, the MMG amplitude versus dynamic torque relationships demonstrated inconsistent linearity. When using MMG in the clinical setting, dynamic muscle actions of the superficial quadriceps femoris muscles do not appear to be appropriate for assessing changes in muscle function during strength training.

  12. How can we strengthen the quadriceps femoris in patients with patellofemoral pain syndrome?

    PubMed Central

    Kaya, Defne; Doral, Mahmut Nedim; Callaghan, Michael

    2012-01-01

    Summary Purpose: the aim of this article was to review the clinical approach of quadriceps strengthening programmes. Methods: a literature search was carried out from 1980 up to September 2011. Eligible studies were those that: (1) evaluated the patients with patellofemoral pain syndrome (not healthy or asymptomatic subjects) (2) examined the effect of kinetic chain exercises (3) examined the effect of weight-bearing exercises (4) compared the effect of the combined exercises programme in the treatment of patients with patellofemoral pain syndrome. Results and conclusion: patients with patellofemoral pain syndrome may tolerate a closed kinetic chain exercises programme better than open kinetic chain. Weight-bearing and non-weight-bearing quadriceps exercises can significantly improve subjective and clinical outcomes in patients with patellofemoral pain syndrome. Combining treatments as an initial approach to treating patellofemoral pain but developing individualized more functional, global treatments are essential. PMID:23738270

  13. Linearity and reliability of the EMG amplitude versus dynamic torque relationships for the superficial quadriceps femoris muscles.

    PubMed

    Stock, M S; Beck, T W; DeFreitas, J M; Dillon, M A

    2010-03-01

    The purpose of the present investigation was to determine the linearity and reliability of the electromyographic (EMG) amplitude versus dynamic torque relationships for the vastus lateralis (VL), rectus femoris (RF), and vastus medialis (VM). Nine healthy men (mean +/- SD age = 25.3 +/- 4.7 years) and eleven healthy women (mean +/- SD age = 22.0 +/- 1.3 years) performed a series of randomly ordered, submaximal to maximal, concentric isokinetic muscle actions of the leg extensors at 30 degrees x s(1) on two occasions separated by at least 48 hours. During each muscle action, surface EMG signals were detected from the VL, RF and VM of the dominant thigh with bipolar surface electrode arrangements. The coefficients of determination for the EMG amplitude versus dynamic torque relationships ranged from r2 = 0.75-0.98 and 0.64-0.99 for the VL, r2 = 0.79-0.99 and 0.60-0.98 for the RFE and r2 = 0.44-0.98 and 0.51-0.98 for the VM for trials 1 and2, respectively. In some cases, the linear EMG amplitude versus torque slope coefficient for trial 1 was significantly different from that for trial 2 for the VL and RF, but not for the VM. The intraclass correlation coefficients for the linear EMG amplitude versus torque coefficients were 0.730 (VL), 0.709 (RF), and 0.888 (VM). These results indicated that the EMG amplitude versus dynamic torque relationships for the superficial quadriceps femoris muscles did not demonstrate enough linearity and reliability to be used for examining the contributions of neural versus hypertrophic factors to training-induced strength gains.

  14. Does sensorimotor cortex activity change with quadriceps femoris torque output? A human electroencephalography study.

    PubMed

    Fry, A; Vogt, T; Folland, J P

    2014-09-05

    Encoding muscular force output during voluntary contractions is widely perceived to result, at least in part, from modulations in neuronal activity within the sensorimotor cortex. However the underlying electrophysiological phenomena associated with increased force output remains unclear. This study directly assessed sensorimotor cortex activity using electroencephalography (EEG) in humans performing isometric knee-extensions at a range of discrete torque levels. Fifteen healthy males (age 24 (s=5) years) completed one familiarization and one experimental trial. Participants performed a cyclic series of 60 isometric knee-extension contractions with the right leg, including 15 contractions of a 5-s duration at each of four discrete torque levels: 15%, 30%, 45% and 60% of maximal voluntary torque (MVT). Isometric knee-extension torque, quadriceps electromyography and EEG were recorded at rest and throughout all the contractions. EEG (0.5-50 Hz) was collected using a 32-channel active-electrode cap. A voxel-based low-resolution brain electromagnetic tomography (LORETA) analysis calculated cortical activation within the sensorimotor cortex (one of 27 MNI coordinates) for the entire 0.5-50-Hz range (cortical current density (CCD)), as well as for each constituent frequency band in this range (delta, theta, alpha, beta and gamma). Gamma band (30-50 Hz) cortical activity increased with contraction torque (analysis of variance [ANOVA], P=0.03). Conversely, activity within the other frequency bands was not modulated by torque (P≥0.09), nor was overall CCD (P=0.11). Peripheral neuromuscular activation (quadriceps electromyography (EMG) amplitude) demonstrated distinct increases between each torque level (P<0.01). In conclusion, sensorimotor cortical activity within the gamma band demonstrated an overall increase with contraction torque, whereas both CCD and each of the other constituent frequency bands were not modulated by increments in torque magnitude during isometric

  15. Relationship between quadriceps femoris muscle volume and muscle torque at least 18 months after anterior cruciate ligament reconstruction.

    PubMed

    Konishi, Y; Oda, T; Tsukazaki, S; Kinugasa, R; Fukubayashi, T

    2012-12-01

    The purpose of this study was to evaluate motor unit recruitment in the quadriceps femoris (QF) after anterior cruciate ligament (ACL) rupture and repair. Subjects included 24 patients at ≥ 18 months after ACL reconstruction and 22 control subjects with no history of knee injury. A series of cross-sectional magnetic resonance images were obtained to compare the QF of patients' injured side with that of their uninjured sides and that of uninjured control subjects. Muscle torque per muscle volume was calculated as isokinetic peak torque divided by QF muscle volume (cm(3)). The mean muscle torque per unit volume of the injured side of patients was not significantly different from that of the uninjured side or control subjects (one-way ANOVA) Results of the present study were contrary to the results of a previous study that evaluated patients at ≤ 12 months after ACL reconstruction. The present study found that high-threshold motor unit recruitment was restored at ≥ 18 months after ACL reconstruction. Thus, clinicians must develop techniques that increase the recruitment of high-threshold motor units in the QF from the period immediately after the injury until approximately 18 months after ACL reconstruction. © 2011 John Wiley & Sons A/S.

  16. The patellar reflex: does activity of quadriceps femoris muscles reflect leg movement?

    PubMed

    Dafkin, Chloe; Green, Andrew; Kerr, Samantha; McKinon, Warrick

    2012-07-01

    The assessment of spinal reflexes has traditionally been performed by clinicians with minimal need for recording equipment, where doctors rely on their training and may use established subjective reflex rating scales. With advances in technology, it is now possible to assess reflexes objectively. This study compared two objective methods of assessing patellar reflex magnitude, duration, and latency, namely electromyography (EMG) of the quadriceps muscles and kinematic assessment of the leg movement around the knee joint. Reflexes of 24 healthy participants were assessed and seven variables were found to describe each reflex. These were the change in knee angle, the velocity of the reflex, the time to maximum knee angle, the biomechanical movement latency, the EMG maximum amplitude, the negative peak duration, and the EMG latency. Spearman's rank correlation tests were run in order to compare all of the variables. The results showed that there were positive correlations between EMG maximum amplitude and the change in knee angle (R(2) = 0.75; P < 0.0001) as well as the EMG maximum amplitude and the velocity of the reflex (R(2) = 0.30; P = 0.0058). There was also a negative correlation between EMG maximum amplitude and the biomechanical movement latency (R(2) = 0.35; P = 0.0024). The results show that there is a relationship between muscle activity and the actual visual movement of the leg assessed using kinematics. This relationship is closest between kinematic measurements and EMG measures of reflex amplitude.

  17. Accuracy and variability of leg velocities during concentric and eccentric actions of the quadriceps femoris muscles.

    PubMed

    Gajdosik, R L; Faris, D W; Kato, T K; Roosa, P F; Matsumoto, T

    1997-04-01

    This study examined the ability to control leg velocities during concentric and eccentric actions of the right quadriceps muscles. Ten healthy women (M age = 25.9 +/- 3.5 yr.) were tested using the Isotonic Program of the KIN-COM II 500H dynamometer. They attempted to match velocity tracings of 10 degrees, 20 degrees, and 40 degrees/sec. through 70 degrees of knee range of motion at a load equal to 10% of their maximal mean concentric force. The actual mean velocities, mean percent deviation from the target velocities, and the coefficient of variation for both actions were calculated for 15 degrees-75 degrees (full range of motion), 15 degrees-45 degrees (shorter range of motion), and 46 degrees-75 degrees (longer range of motion). Separate one-way analyses of variance with two trial factors (action x velocity) showed faster concentric velocities through the full and longer ranges of motion, and faster eccentric velocities through the shorter range of motion. Mean percent deviations indicated that the eccentric velocities were generally more accurate within all ranges of motion. Larger concentric coefficients of variation were found within the full and longer ranges of motion, and the coefficients of variation for both actions decreased as the velocities increased. An exaggerated 'velocity overshoot' at the onset of both actions probably contributed to differences in the velocities and coefficients of variation. The results indicated differences between the concentric and eccentric actions, explained in part by the testing methodology used and by the known mechanical and physiological characteristics of the two muscle actions.

  18. Messenger RNA profiling of rabbit quadriceps femoris after repeat injections of botulinum toxin: Evidence for a dynamic pattern without further structural alterations.

    PubMed

    Hart, David A; Fortuna, Rafael; Herzog, Walter

    2017-08-18

    Onabotulinum toxin type A (BoNT-A) is widely used clinically, but it may cause adverse effects. Earlier studies showed repeat BoNT-A injections did not cause progressive atrophy or function loss. The purpose of this study was to assess the influence of repeat BoNT-A injections into rabbit muscle on subsequent molecular alterations. Twenty-two rabbits received 0, 1, 2, or 3 BoNT-A injections in the quadriceps femoris muscle at 3-month intervals and were euthanized 6 months after the last injection. Aliquots of both injected and contralateral muscle were frozen, and the total RNA quantified. Total RNA per illigram wet weight tissue was significantly elevated compared with control after 1, 2, or 3 BoNT-A injections. Analysis of mRNA levels for inflammatory molecules, proteinases, adipokines, and mesenchymal stem cells were elevated with increasing BoNT-A injections in injected leg and contralateral leg. Future studies should focus on the safety and possible complications of repeat BoNT-A treatments. Muscle Nerve, 2017. © 2017 The Authors Muscle & Nerve Published by Wiley Periodicals, Inc.

  19. Inter- and intramuscular differences in training-induced hypertrophy of the quadriceps femoris: association with muscle activation during the first training session.

    PubMed

    Wakahara, Taku; Ema, Ryoichi; Miyamoto, Naokazu; Kawakami, Yasuo

    2017-07-01

    The purpose of this study was to examine whether inter- and intramuscular differences in hypertrophy induced by resistance training correspond to differences in muscle activation during the first training session. Eleven young men completed 12 weeks of training intervention for knee extension. Before and after the intervention, T1-weighted magnetic resonance (MR) images were recorded to determine the volume and anatomical cross-sectional area (CSA) along the length of the individual muscles of the quadriceps femoris. The T2-weighted MR images were also acquired before and immediately after the first training session. The T2 was calculated for each pixel within the quadriceps femoris, from which the muscle activation was evaluated as %activated volume and area. The results showed that the %activated volume after the first training session was significantly higher in the vastus intermedius than the vastus medialis. However, the relative change in muscle volume after the training intervention was significantly greater in the rectus femoris than the vasti muscles (vastus lateralis, intermedius and medialis). Within the rectus femoris, both the %activated area and relative increase in CSA were significantly greater in the distal region than the proximal region. In contrast, the %activated area and relative increase in CSA of the vasti were nearly uniform along each muscle. These results suggest that the muscle activation during the first training session is associated with the intramuscular difference in hypertrophy induced by training intervention, but not with the intermuscular difference. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

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

    PubMed

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

    2015-11-01

    Young athletes who have had anterior cruciate ligament (ACL) reconstruction demonstrate suboptimal rates of return to sport, high rates of second ACL injuries, and persistent movement asymmetries. Therefore, the influence of musculoskeletal impairments on movement mechanics in this population needs to be further evaluated. The primary hypothesis was that among young athletes who have had ACL reconstruction, those with greater quadriceps strength asymmetry would demonstrate altered single-leg drop-landing mechanics at return to sport compared with individuals with more symmetric quadriceps strength and also compared with healthy controls (ie, those with no ACL reconstruction). A second hypothesis was that quadriceps strength symmetry would predict single-leg drop-landing symmetry in individuals who have undergone ACL reconstruction. Controlled laboratory study. The study entailed a total of 103 participants (age, 17.4 years) at the time of return to sport after ACL reconstruction and 47 control participants (age, 17.0 years). The quadriceps index (QI) was calculated for isometric quadriceps strength, which was then used to divide the ACL reconstruction participants into high-quadriceps (QI ≥90%; n = 52) and low-quadriceps (QI <85%; n = 41) subgroups. Biomechanical data were collected by use of 3-dimensional motion analysis during a single-leg drop-landing task. The LSI was calculated for kinematic and kinetic sagittal-plane variables of interest during landing. Group differences were compared by use of 1-way analysis of variance and linear regression analyses (α < .05). Both the low- and high-quadriceps groups demonstrated greater limb asymmetry during landing compared with the control group in knee flexion excursion (mean LSI ± SD: low quadriceps, 85.8% ± 15.5% [P < .001]; high quadriceps, 94.2% ± 15.6% [P = .019]; control, 102.7% ± 14.1%), peak trunk flexion angle (low quadriceps, 129.2% ± 36.6% [P < .001]; high quadriceps, 110.5% ± 22.6% [P = .03

  1. The effect of local skin cooling before a sustained, submaximal isometric contraction on fatigue and isometric quadriceps femoris performance: A randomized controlled trial.

    PubMed

    Hohenauer, Erich; Cescon, Corrado; Deliens, Tom; Clarys, Peter; Clijsen, Ron

    2017-04-01

    The central- and peripheral mechanisms by which heat strain limits physical performance are not fully elucidated. Nevertheless, pre-cooling is often used in an attempt to improve subsequent performance. This study compared the effects of pre-cooling vs. a pre-thermoneutral application on central- and peripheral fatigue during 60% of isometric maximum voluntary contraction (MVC) of the right quadriceps femoris muscle. Furthermore, the effects between a pre-cooling and a pre-thermoneutral application on isometric MVC of the right quadriceps femoris muscle and subjective ratings of perceived exertion (RPE) were investigated. In this randomized controlled trial, 18 healthy adults voluntarily participated. The participants received either a cold (experimental) application (+8°C) or a thermoneutral (control) application (+32°C) for 20min on their right thigh (one cuff). After the application, central (fractal dimension - FD) and peripheral (muscle fiber conduction velocity - CV) fatigue was estimated using sEMG parameters during 60% of isometric MVC. Surface EMG signals were detected from the vastus medialis and lateralis using bidimensional arrays. Immediately after the submaximal contraction, isometric MVC and RPE were assessed. Participants receiving the cold application were able to maintain a 60% isometric MVC significantly longer when compared to the thermoneutral group (mean time: 78 vs. 46s; p=0.04). The thermoneutral application had no significant impact on central fatigue (p>0.05) compared to the cold application (p=0.03). However, signs of peripheral fatigue were significantly higher in the cold group compared to the thermoneutral group (p=0.008). Pre-cooling had no effect on isometric MVC of the right quadriceps muscle and ratings of perceived exertion. Pre-cooling attenuated central fatigue and led to significantly longer submaximal contraction times compared to the pre-thermoneutral application. These findings support the use of pre-cooling procedures

  2. Voluntary activation failure is detectable in some myositis patients with persisting quadriceps femoris weakness: an observational study.

    PubMed

    Molloy, Catherine B; Al-Omar, Ahmed O; Edge, Kathryn T; Cooper, Robert G

    2006-01-01

    This cross-sectional, observational study was undertaken to examine whether voluntary activation failure could contribute to the persisting weakness observed in some patients with treated idiopathic inflammatory myositis. In 20 patients with myositis of more than six months' duration (5 males, 15 females; mean [+/- 1 SD] age 53 11 years) and 102 normal subjects (44 males, 58 females; mean age 32 8 years), isometric maximum voluntary contractions (MVCs) of the dominant quadriceps femoris (QF) were quantified. Absolute MVC results of normal subjects and patients were then normalised with respect to lean body mass (force per units of lean body mass), giving a result in Newtons per kilogram. Based on mass-normalised force data of normal subjects, patients were arbitrarily stratified into "weak" and "not weak" subgroups. During further MVC attempts, the "twitch interpolation" technique was used to assess whether the QF voluntary activation of patients was complete. This technique relies on the fact that, because muscle activation is incomplete during submaximal voluntary contractions, electrical stimulation of the muscle can induce force increments superimposed on the submaximal voluntary force being generated. No between-gender differences were seen in the mass-normalised MVC results of healthy subjects, so the gender-combined results of 6.6 (1.5) N/kg were used for patient stratification. No between-gender difference was found for mass-normalised MVCs in patients: males 5.4 (3.2) and females 3.0 (1.7) N/kg (p > 0.05). Mass-normalised MVCs of male patients were as great as those of normal subjects (p > 0.05), but mass-normalised MVCs of female patients were significantly smaller than those of the normal subjects (p < 0.001). Only one of the six "not weak" patients exhibited interpolated twitches during electrical stimulation, but six of the 14 "weak" patients did, the biggest twitches being seen in the weakest patient. That interpolated twitches can be induced in some

  3. Voluntary activation failure is detectable in some myositis patients with persisting quadriceps femoris weakness: an observational study

    PubMed Central

    Molloy, Catherine B; Al-Omar, Ahmed O; Edge, Kathryn T; Cooper, Robert G

    2006-01-01

    This cross-sectional, observational study was undertaken to examine whether voluntary activation failure could contribute to the persisting weakness observed in some patients with treated idiopathic inflammatory myositis. In 20 patients with myositis of more than six months' duration (5 males, 15 females; mean [± 1 SD] age 53 [11] years) and 102 normal subjects (44 males, 58 females; mean age 32 [8] years), isometric maximum voluntary contractions (MVCs) of the dominant quadriceps femoris (QF) were quantified. Absolute MVC results of normal subjects and patients were then normalised with respect to lean body mass (force per units of lean body mass), giving a result in Newtons per kilogram. Based on mass-normalised force data of normal subjects, patients were arbitrarily stratified into "weak" and "not weak" subgroups. During further MVC attempts, the "twitch interpolation" technique was used to assess whether the QF voluntary activation of patients was complete. This technique relies on the fact that, because muscle activation is incomplete during submaximal voluntary contractions, electrical stimulation of the muscle can induce force increments superimposed on the submaximal voluntary force being generated. No between-gender differences were seen in the mass-normalised MVC results of healthy subjects, so the gender-combined results of 6.6 (1.5) N/kg were used for patient stratification. No between-gender difference was found for mass-normalised MVCs in patients: males 5.4 (3.2) and females 3.0 (1.7) N/kg (p > 0.05). Mass-normalised MVCs of male patients were as great as those of normal subjects (p > 0.05), but mass-normalised MVCs of female patients were significantly smaller than those of the normal subjects (p < 0.001). Only one of the six "not weak" patients exhibited interpolated twitches during electrical stimulation, but six of the 14 "weak" patients did, the biggest twitches being seen in the weakest patient. That interpolated twitches can be induced in

  4. [Amino acid composition of the rat quadriceps femoris muscle after a flight on the Kosmos-936 biosatellite].

    PubMed

    Vlasova, T F; Miroshnikova, E B; Poliakov, V V; Murugova, T P

    1982-01-01

    The amino acid composition of the quadriceps muscle of rats flown onboard the biosatellite Cosmos-936 and exposed to the ground-based synchronous control experiment was studied. The weightless rats showed changes in the amino acid concentration in the quadriceps muscle. The centrifuged flight and synchronous rats displayed an accumulation of free amino acids in the above muscle.

  5. The dependence between clinical condition and value of the maximum force in the quadriceps femoris muscle during MVC test in patients with knee osteoarthritis.

    PubMed

    Nowak, Karina; Sobota, Grzegorz; Bacik, Bogdan; Hajduk, Grzegorz; Kusz, Damian

    2012-01-01

    The aim of this study was to check whether there was a correlation between the value of the maximum developed torque of the quadriceps femoris muscle and subjective evaluation of a patient's pain which is measured by the VAS. Also evaluated were changes in the muscle torque value and KSS scale over time. For examining patient's condition use was made of a KSS scale (knee score: pain, range of motion, stability of joint and limb axis) before the surgery and in weeks 6 and 12, as well as 6 months after surgery. It was found to be constantly improving in comparison with the condition before the surgery. This is confirmed by a significant statistical value difference of KSS scale. The surgery substantially increases the quality of live and function recurrence.

  6. Anatomical cross-sectional area of the quadriceps femoris and sit-to-stand test score in middle-aged and elderly population: development of a predictive equation.

    PubMed

    Saito, Akira; Ema, Ryoichi; Inami, Takayuki; Maeo, Sumiaki; Otsuka, Shun; Higuchi, Mitsuru; Shibata, Shigenobu; Kawakami, Yasuo

    2016-06-29

    Although the sit-to-stand (STS) test score has been shown to relate to the strength and size of the quadriceps femoris (QF) for elderly population, it is unknown whether this relationship is influenced by a posture (i.e., the trunk being allowed to stoop or not) during the STS test. The present study investigated the relationship between STS test score and QF anatomical cross-sectional area (ACSA) in the middle-aged and elderly population with regard to the difference in the posture during STS test, and aimed to develop an accurate predicting equation of the QF ACSA from the STS test score. 105 males (40-81 years) and 113 females (41-79 years) participated in the present study, then the subjects were divided at random as validation and cross-validation groups. Mid-thigh QF ACSA was determined by magnetic resonance imaging. Subjects performed a 10-repeated STS as fast as possible in two conditions: (1) with the trunk being allowed to stoop during the sitting phases, and (2) kept upright throughout the test. A power index of the STS test score was calculated based on an equation obtained in a previous study using the time taken for each test condition, the thigh and shank lengths, and body mass. In the validation group (n = 109), a stepwise multiple linear regression analysis was performed to create a predictive model of the ACSA with sex, age, the STS time, and power for both conditions as independent variables. The formulated predictive equation was examined in the cross-validation group (n = 109). In the validation group, a stepwise regression analysis revealed that STS power with upright trunk condition, sex, and age but not with the stooping condition, were selected as variables to predict QF ACSA (R (2) = 0.64, P < 0.001). There was no systematic error for the relationship between predicted and measured values in the cross-validation group. These results indicate that STS test score with upright trunk condition is one of the indices of QF

  7. Local architecture of the vastus intermedius is a better predictor of knee extension force than that of the other quadriceps femoris muscle heads.

    PubMed

    Ando, Ryosuke; Saito, Akira; Umemura, Yoshihisa; Akima, Hiroshi

    2015-09-01

    The purpose of this study was to determine whether the muscle architecture of each head of the quadriceps femoris (QF) at multiple regions can be used to predict knee extension force. Muscle thickness and pennation angle were measured using sonographic images from multiple regions on each muscle of the QF with the knee flexed to 90°. The fascicle lengths of the rectus femoris (RF), vastus lateralis (VL) and vastus intermedius (VI) muscles were estimated based on sonographic images taken along the length of the thigh. The muscle architecture of the vastus intermedius was determined in two separate locations using sonographic images of the anterior (ant-VI) and lateral portions (lat-VI). The maximal voluntary contraction (MVC) was measured during isometric knee extension at a knee joint angle of 90°. The relationship between MVC force and muscle architecture was examined using a stepwise linear regression analysis with MVC force as the dependent variable. The muscle thickness of the ant-VI was selected as an independent variable in the first step of the linear regression analysis (R(2) = 0.66, P<0.01). In the second step, pennation angle of the lat-VI was added to the model (R(2) = 0.91, P<0.01). These results suggest that among the four muscles that make up the QF, the muscle architecture of the VI is the best predictor of knee extension force. © 2014 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  8. Association between leg strength and muscle cross-sectional area of the quadriceps femoris with the physical activity level in octogenarians.

    PubMed

    Latorre-Román, Pedro Á; Arévalo-Arévalo, Juan Manuel; García-Pinillos, Felipe

    2016-06-03

    Aging is a complex physiological process whose main feature is the progressive loss of functionality, which may be delayed or attenuated by improving physical fitness.  To determine the association between leg strength and the muscle cross-sectional area of the quadriceps femoris in relation to physical activity level in the elderly.  Thirty-two functionally autonomous people over 80 years (men: 82.80±2.09 years; women: 83.77±4.09 years) participated in this study. The Barthel Index, the Yale Physical Activity Survey and the Chair Stand Test were the instruments used.  There were significant differences between sexes in muscle area (p<0.001) in the Chair Stand Test (p=0.028) and the walk index (p=0.029), with higher values in men. The muscle area and the Chair Stand Test correlated significantly with the walk index (r=0.445, p<0.005, and r=0.522, p<0.001, respectively) and the total weekly activity index (r=0.430, p<0.005, and r=0.519, p<0.001, respectively). In the multiple linear regression models for the total weekly activity index, muscle area and the Chair Stand Test, only the latter behaved as a predictor variable.  Muscle strength and muscle mass of quadriceps showed a significant association with the physical activity level in older people. Leg muscle strength was useful to reveal muscle mass and physical activity level in older people, which is relevant as a clinical practice indicator.

  9. Comparison between voluntary and stimulated contractions of the quadriceps femoris for growth hormone response and muscle damage.

    PubMed

    Jubeau, Marc; Sartorio, Alessandro; Marinone, Pier Giulio; Agosti, Fiorenza; Van Hoecke, Jacques; Nosaka, Kazunori; Maffiuletti, Nicola A

    2008-01-01

    This study aimed to compare voluntary and stimulated exercise for changes in muscle strength, growth hormone (GH), blood lactate, and markers of muscle damage. Nine healthy men had two leg press exercise bouts separated by 2 wk. In the first bout, the quadriceps muscles were stimulated by biphasic rectangular pulses (75 Hz, duration 400 mus, on-off ratio 6.25-20 s) with current amplitude being consistently increased throughout 40 contractions at maximal tolerable level. In the second bout, 40 voluntary isometric contractions were performed at the same leg press force output as the first bout. Maximal voluntary isometric strength was measured before and after the bouts, and serum GH and blood lactate concentrations were measured before, during, and after exercise. Serum creatine kinase (CK) activity and muscle soreness were assessed before, immediately after, and 24, 48, and 72 h after exercise. Maximal voluntary strength decreased significantly (P < 0.05) after both bouts, but the magnitude of the decrease was significantly (P < 0.05) greater for the stimulated contractions (-22%) compared with the voluntary contractions (-9%). Increases in serum GH and lactate concentrations were significantly (P < 0.05) larger after the stimulation compared with the voluntary exercise. Increases in serum CK activity and muscle soreness were also significantly (P < 0.05) greater for the stimulation than voluntary exercise. It was concluded that a single bout of electrical stimulation exercise resulted in greater GH response and muscle damage than voluntary exercise.

  10. Event-related differences in the cross-sectional areas and torque generation capabilities of quadriceps femoris and hamstrings in male high school athletes.

    PubMed

    Hoshikawa, Yoshihiro; Muramatsu, Masataka; Iida, Tomomi; Uchiyama, Akiko; Nakajima, Yoshiharu; Kanehisa, Hiroaki

    2010-01-01

    This study investigated the event-related differences in the cross-sectional areas (CSAs) and torque generation capabilities of the quadriceps femoris (QF) and hamstrings (HAM) in male high school athletes. Subjects were soccer players (n=32), volleyball players (21), rowers (29), karate athletes (18), sumo wrestlers (15), sprinters (22), throwers (16), and nonathletes (20). The CSAs of QF and HAM at the mid-thigh were determined using magnetic resonance imaging. In addition, isokinetic torques during knee extension and flexion were determined at a pre-set velocity of 1.05 rad/s. The CSAs of the two muscle groups and torques developed in the two motions were significantly related to the two-third power of lean body mass (LBM(2/3)) and the product of CSA and femur length (CSA*fl), calculated as an index of muscle volume, respectively. CSA relative to LBM(2/3) for QF did not differ among the groups, but that for HAM was higher in sprinters, soccer players, throwers, and karate athletes than in sumo wrestlers, rowers, volleyball players, and nonathletes. Knee extension torque relative to the CSA*fl of QF was higher in karate athletes, soccer players, and rowers than in nonathletes, but the corresponding value for knee flexion did not differ among groups. Thus, the present study indicated that, at least in male high school athletes, the event-related differences in LBM and the muscularity of QF and HAM produced the corresponding differences in the CSAs of the reciprocal muscle groups and knee extension and flexion torques, respectively. However, specific profiles related to competitive and/or training styles exist in HAM CSA and knee extension torque, which cannot be explained by the magnitude of LBM and QF CSA, respectively.

  11. Magnitude of Deformity Correction May Influence Recovery of Quadriceps Strength After Total Knee Arthroplasty.

    PubMed

    Loyd, Brian J; Jennings, Jason M; Falvey, Jason R; Kim, Raymond H; Dennis, Douglas A; Stevens-Lapsley, Jennifer E

    2017-09-01

    Malalignment of the lower extremity is commonly seen in patients with severe osteoarthritis undergoing total knee arthroplasty (TKA) and is believed to play a role in quadriceps strength loss. Deformity correction is typically achieved through surgical techniques to provide appropriate ligamentous balancing. Therefore, this study examined the influence of change in lower extremity alignment on quadriceps strength outcomes after TKA. Seventy-three participants (36 male; mean age, 62 years; and mean body mass index, 29.7 kg/m(2)) undergoing primary unilateral TKA were used in this investigation. Before surgery and at 1 and 6 months after surgery, measures of isometric knee extensor strength, quadriceps activation, and long-standing plain films were collected. Using the films, measures of mechanical axis, distal femoral angle (DFA), proximal tibial angle, and patellofemoral angle were performed. Hierarchical linear regression was used to evaluate how change in alignment from baseline to 1 and 6 months influenced the change in quadriceps strength. DFA was found to significantly contribute to changes in quadriceps strength at 1 and 6 months after TKA above those contributed by associated covariates. None of the other measures of lower extremity alignment were found to contribute to quadriceps strength in this sample. Reductions in quadriceps strength experienced after TKA are likely to be influenced by changes in lower extremity alignment. Specifically, measures of DFA were found to significantly contribute to these changes. Future work is needed to prospectively examine measures of lower extremity alignment change and recovery after TKA. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Kinesiology Taping does not Modify Electromyographic Activity or Muscle Flexibility of Quadriceps Femoris Muscle: A Randomized, Placebo-Controlled Pilot Study in Healthy Volleyball Players.

    PubMed

    Halski, Tomasz; Dymarek, Robert; Ptaszkowski, Kuba; Słupska, Lucyna; Rajfur, Katarzyna; Rajfur, Joanna; Pasternok, Małgorzata; Smykla, Agnieszka; Taradaj, Jakub

    2015-08-01

    Kinesiology taping (KT) is a popular method of supporting professional athletes during sports activities, traumatic injury prevention, and physiotherapeutic procedures after a wide range of musculoskeletal injuries. The effectiveness of KT in muscle strength and motor units recruitment is still uncertain. The objective of this study was to assess the effect of KT on surface electromyographic (sEMG) activity and muscle flexibility of the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) muscles in healthy volleyball players. Twenty-two healthy volleyball players (8 men and 14 women) were included in the study and randomly assigned to 2 comparative groups: "kinesiology taping" (KT; n=12; age: 22.30 ± 1.88 years; BMI: 22.19 ± 4.00 kg/m(2)) in which KT application over the RF muscle was used, and "placebo taping" (PT; n=10; age: 21.50 ± 2.07 years; BMI: 22.74 ± 2.67 kg/m(2)) in which adhesive nonelastic tape over the same muscle was used. All subjects were analyzed for resting sEMG activity of the VL and VM muscles, resting and functional sEMG activity of RF muscle, and muscle flexibility of RF muscle. No significant differences in muscle flexibility of the RF muscle and sEMG activity of the RF, VL, and VM muscles were registered before and after interventions in both groups, and between the KT and PT groups (p>0.05). The results show that application of the KT to the RF muscle is not useful to improve sEMG activity.

  13. Kinesiology Taping does not Modify Electromyographic Activity or Muscle Flexibility of Quadriceps Femoris Muscle: A Randomized, Placebo-Controlled Pilot Study in Healthy Volleyball Players

    PubMed Central

    Halski, Tomasz; Dymarek, Robert; Ptaszkowski, Kuba; Słupska, Lucyna; Rajfur, Katarzyna; Rajfur, Joanna; Pasternok, Małgorzata; Smykla, Agnieszka; Taradaj, Jakub

    2015-01-01

    Background Kinesiology taping (KT) is a popular method of supporting professional athletes during sports activities, traumatic injury prevention, and physiotherapeutic procedures after a wide range of musculoskeletal injuries. The effectiveness of KT in muscle strength and motor units recruitment is still uncertain. The objective of this study was to assess the effect of KT on surface electromyographic (sEMG) activity and muscle flexibility of the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) muscles in healthy volleyball players. Material/Methods Twenty-two healthy volleyball players (8 men and 14 women) were included in the study and randomly assigned to 2 comparative groups: “kinesiology taping” (KT; n=12; age: 22.30±1.88 years; BMI: 22.19±4.00 kg/m2) in which KT application over the RF muscle was used, and “placebo taping” (PT; n=10; age: 21.50±2.07 years; BMI: 22.74±2.67 kg/m2) in which adhesive nonelastic tape over the same muscle was used. All subjects were analyzed for resting sEMG activity of the VL and VM muscles, resting and functional sEMG activity of RF muscle, and muscle flexibility of RF muscle. Results No significant differences in muscle flexibility of the RF muscle and sEMG activity of the RF, VL, and VM muscles were registered before and after interventions in both groups, and between the KT and PT groups (p>0.05). Conclusions The results show that application of the KT to the RF muscle is not useful to improve sEMG activity. PMID:26232122

  14. Reduced biceps femoris myoelectrical activity influences eccentric knee flexor weakness after repeat sprint running.

    PubMed

    Timmins, R G; Opar, D A; Williams, M D; Schache, A G; Dear, N M; Shield, A J

    2014-08-01

    The aim of this study was to determine whether declines in knee flexor strength following overground repeat sprints were related to changes in hamstrings myoelectrical activity. Seventeen recreationally active men completed maximal isokinetic concentric and eccentric knee flexor strength assessments at 180°/s before and after repeat sprint running. Myoelectrical activity of the biceps femoris (BF) and medial hamstrings (MHs) was measured during all isokinetic contractions. Repeated measures mixed model [fixed factors = time (pre- and post-repeat sprint) and leg (dominant and nondominant), random factor = participants] design was fitted with the restricted maximal likelihood method. Repeat sprint running resulted in significant declines in eccentric, and concentric, knee flexor strength (eccentric = 26 ± 4 Nm, 15% P < 0.001; concentric 11 ± 2 Nm, 10% P < 0.001). Eccentric BF myoelectrical activity was significantly reduced (10%; P = 0.035). Concentric BF and all MH myoelectrical activity were not altered. The declines in maximal eccentric torque were associated with the change in eccentric BF myoelectrical activity (P = 0.013). Following repeat sprint running, there were preferential declines in the myoelectrical activity of the BF, which explained declines in eccentric knee flexor strength.

  15. Influence of angular velocity on vastus lateralis and rectus femoris oxygenation dynamics during knee extension exercises.

    PubMed

    Denis, Romain; Wilkinson, Jennifer; De Vito, Giuseppe

    2011-09-01

    The purpose of this study was to investigate whether changes in angular velocity would alter vastus lateralis (VL) and rectus femoris (RF) oxygenation status during maximal isokinetic knee extension exercises. Eleven recreationally active male participants randomly performed ten maximal knee extensions at 30, 60, 120 and 240° s(-1). Tissue oxygenation index (TOI) and total haemoglobin concentration ([tHb]) were acquired from the VL and RF muscles by means of near-infrared spectroscopy (NIRS). Breath-by-breath pulmonary oxygen consumption (VO(2p)) was recorded throughout the tests. Peak torque and VO(2p) significantly decreased as a function of velocity (P<0·05). Interestingly, RF and VL TOI significantly increased as a function of velocity (P<0·05), whereas [tHb] significantly decreased as a function of velocity (P<0·05). A greater number of muscle fibre recruited at slow velocity, where the torque and VO(2p) were the highest, might explain the lower VL and RF TOI observed herein. Furthermore, the increase in local blood flow (suggested by [tHb] changes) during isokinetic knee extension exercises performed at slow angular velocity might have been induced by a higher intramuscular pressure during the contraction phases as well as a greater microcirculatory vasodilatation during relaxation phases. Implementing slow-velocity isokinetic exercises in rehabilitation or other training programmes could delay the short-term anoxia generated by such exercises and result in muscle metabolism enhancement.

  16. In vitro investigation of the influence of tibial slope on quadriceps extension force after total knee arthroplasty.

    PubMed

    Ostermeier, Sven; Hurschler, Christof; Windhagen, Henning; Stukenborg-Colsman, Christina

    2006-10-01

    The purpose of this study was to investigate the influence of tibial base plate angulation on knee kinematics and kinetics during knee arthroplasty. The amount of quadriceps force required to extend the knee and the anteroposterior displacement of a mobile bearing insert as well as tibiofemoral position were measured during an in vitro simulation of an isokinetic knee extension cycle. Human knee specimens (n = 7, mean age 62, range 52-75 years, all male) were tested in a kinematic knee simulating machine after total knee arthroplasty (TKA) with a mobile bearing insert prosthesis (Interax), Stryker/Howmedica). During simulation, a hydraulic cylinder applied sufficient force to the quadriceps tendon to produce an extension moment of 31 N m about the knee. The quadriceps load was measured using a load cell attached to the quadriceps tendon, the anteroposterior displacement of the mobile bearing insert as well as the relative tibiofemoral position was measured using an ultrasound base motion analysis system (CMS 100, Zebris). Quadriceps load, insert and tibial displacement were first investigated with the tibial base plate implanted with a neutral tibial base plate orientation, and subsequently after 10 degrees posterior angulation. The quadriceps forces needed to produce a 31 N m knee extension moment after TKA with neutral slope reached levels as high as 1,391 N (SD 82 N). After applying a posterior slope of 10 degrees , maximum quadriceps force was measured to be up to 1,303 N (SD 34 N, P = 0.04). The mobile bearing insert was observed to move up to 0.1 mm (SD 4.2 mm) anteriorly relative to the tibial base plate with neutral tibial slope, and up to 1.0 mm (SD 4.5 mm, P = 0.47) with tibial slope. Femoral position relative to the tibia moved from a posterior position of 13.1 mm (SD 4.0 mm) anteriorly up to 0.5 mm (SD 6.3 mm), and from 16.0 mm (SD 6.4 mm, P = 0.67) to 9.5 mm (SD 9.9 mm, P = 0.33) with a 10 degrees tibial slope. Posterior slope of the tibial base plate

  17. Prolonged infrapatellar tendon vibration does not influence quadriceps maximal or explosive isometric force production in man.

    PubMed

    Fry, Adam; Folland, Jonathan P

    2014-08-01

    The influence of muscle/tendon vibration on maximal muscle performance is unclear. This study examined the effect of a prolonged tendon vibration stimulus on maximum voluntary contraction (MVC) and explosive voluntary contraction (EVC) performance. Eighteen young healthy males (nine strength trained and nine untrained) completed a series of isometric unilateral knee extensions (EVCs, electrically evoked octet responses, MVCs, ramp contractions) pre and post two separate 30-min intervention trials; infrapatellar tendon vibration (80 Hz), and quiet sitting (control). H max and M max were measured at the start and end of each series of contractions, both pre- and post-intervention (i.e., at four time points). Knee extensor force and both quadriceps and hamstrings EMG were measured throughout each series of contractions. Vibration had no effect on either maximum force (ANOVA, trial × time interaction P = 0.92), explosive force (P ≥ 0.36), or the associated agonist EMG amplitude during these tasks (P ≥ 0.23). Octet responses were also unaffected by vibration (P ≥ 0.39). Conversely, post-intervention H max/M max was 60 % lower in the vibration trial vs. control, and remained 38 % lower at the end of the post-intervention measurements (t test, both P < 0.01). Individual H max/M max depression did not correlate to changes in either maximum or explosive force (Spearman's Rank, P ≥ 0.54), and training status had no influence on the effect of vibration. Prolonged infrapatellar tendon vibration depressed H-reflex amplitude, but did not affect either maximal or explosive isometric force production of the quadriceps.

  18. Musculotendon variability influences tissue strains experienced by the biceps femoris long head muscle during high-speed running.

    PubMed

    Fiorentino, Niccolo M; Blemker, Silvia S

    2014-10-17

    The hamstring muscles frequently suffer injury during high-speed running, though the factors that make an individual more susceptible to injury remain poorly understood. The goals of this study were to measure the musculotendon dimensions of the biceps femoris long head (BFlh) muscle, the hamstring muscle injured most often, and to use computational models to assess the influence of variability in the BFlh's dimensions on internal tissue strains during high-speed running. High-resolution magnetic resonance (MR) images were acquired over the thigh in 12 collegiate athletes, and musculotendon dimensions were measured in the proximal free tendon/aponeurosis, muscle and distal free tendon/aponeurosis. Finite element meshes were generated based on the average, standard deviation and range of BFlh dimensions. Simulation boundary conditions were defined to match muscle activation and musculotendon length change in the BFlh during high-speed running. Muscle and connective tissue dimensions were found to vary between subjects, with a coefficient of variation (CV) of 17±6% across all dimensions. For all simulations peak local strain was highest along the proximal myotendinous junction, which is where injury typically occurs. Model variations showed that peak local tissue strain increased as the proximal aponeurosis width narrowed and the muscle width widened. The aponeurosis width and muscle width variation models showed that the relative dimensions of these structures influence internal muscle tissue strains. The results of this study indicate that a musculotendon unit's architecture influences its strain injury susceptibility during high-speed running.

  19. Influence of extended aging on beef quality characteristics and sensory perception of steaks from the biceps femoris and semimembranosus.

    PubMed

    Colle, M J; Richard, R P; Killinger, K M; Bohlscheid, J C; Gray, A R; Loucks, W I; Day, R N; Cochran, A S; Nasados, J A; Doumit, M E

    2016-09-01

    The objective was to determine the influence of post-fabrication aging (2, 14, 21, 42, and 63days) on beef quality characteristics and consumer sensory perception of biceps femoris (BF) and semimembranosus (SM) steaks. Lipid oxidation and aerobic plate counts increased (P<0.05) with longer aging periods and retail display times. An aging period by day of retail display interaction (P<0.05) was observed for a* and b* values of the BF and SM. Warner-Bratzler shear force values decreased (P<0.05) with longer aging for the SM, while no difference was observed for the BF. Consumer panel results revealed that longer aging periods increased (P<0.05) acceptability of the SM, tenderness of both muscles, and tended to increase (P=0.07) juiciness of the SM. Our results show that extended aging reduces retail color stability yet has positive effects on consumer perception of tenderness of both muscles and overall acceptability of the SM.

  20. Musculotendon variability influences tissue strains experienced by the biceps femoris long head muscle during high-speed running

    PubMed Central

    Fiorentino, Niccolo M.; Blemker, Silvia S.

    2014-01-01

    The hamstring muscles frequently suffer injury during high-speed running, though the factors that make an individual more susceptible to injury remain poorly understood. The goals of this study were to measure the musculotendon dimensions of the biceps femoris long head (BFlh) muscle, the hamstring muscle injured most often, and to use computational models to assess the influence of variability in the BFlh’s dimensions on internal tissue strains during high-speed running. High-resolution magnetic resonance (MR) images were acquired over the thigh in 12 collegiate athletes, and musculotendon dimensions were measured in the proximal free tendon/aponeurosis, muscle and distal free tendon/aponeurosis. Finite element meshes were generated based on the average, standard deviation and range of BFlh dimensions. Simulation boundary conditions were defined to match muscle activation and musculotendon length change in the BFlh during high-speed running. Muscle and connective tissue dimensions were found to vary between subjects, with a coefficient of variation (CV) of 17 ± 6% across all dimensions. For all simulations peak local strain was highest along the proximal myotendinous junction, which is where injury typically occurs. Model variations showed that peak local tissue strain increased as the proximal aponeurosis width narrowed and the muscle width widened. The aponeurosis width and muscle width variation models showed that the relative dimensions of these structures influence internal muscle tissue strains. The results of this study indicate that a musculotendon unit’s architecture influences its strain injury susceptibility during high-speed running. PMID:25189094

  1. Rectus femoris muscle injuries in football: a clinically relevant review of mechanisms of injury, risk factors and preventive strategies.

    PubMed

    Mendiguchia, Jurdan; Alentorn-Geli, Eduard; Idoate, Fernando; Myer, Gregory D

    2013-04-01

    Quadriceps muscle strains frequently occur in sports that require repetitive kicking and sprinting, and are common in football in its different forms around the world. This paper is a review of aetiology, mechanism of injury and the natural history of rectus femoris injury. Investigating the mechanism and risk factors for rectus femoris muscle injury aims to allow the development of a framework for future initiatives to prevent quadriceps injury in football players.

  2. Influence of step rate and quadriceps load distribution on patellofemoral cartilage contact pressures during running.

    PubMed

    Lenhart, Rachel L; Smith, Colin R; Vignos, Michael F; Kaiser, Jarred; Heiderscheit, Bryan C; Thelen, Darryl G

    2015-08-20

    Interventions used to treat patellofemoral pain in runners are often designed to alter patellofemoral mechanics. This study used a computational model to investigate the influence of two interventions, step rate manipulation and quadriceps strengthening, on patellofemoral contact pressures during running. Running mechanics were analyzed using a lower extremity musculoskeletal model that included a knee with six degree-of-freedom tibiofemoral and patellofemoral joints. An elastic foundation model was used to compute articular contact pressures. The lower extremity model was scaled to anthropometric dimensions of 22 healthy adults, who ran on an instrumented treadmill at 90%, 100% and 110% of their preferred step rate. Numerical optimization was then used to predict the muscle forces, secondary tibiofemoral kinematics and all patellofemoral kinematics that would generate the measured primary hip, knee and ankle joint accelerations. Mean and peak patella contact pressures reached 5.0 and 9.7MPa during the midstance phase of running. Increasing step rate by 10% significantly reduced mean contact pressures by 10.4% and contact area by 7.4%, but had small effects on lateral patellar translation and tilt. Enhancing vastus medialis strength did not substantially affect pressure magnitudes or lateral patellar translation, but did shift contact pressure medially toward the patellar median ridge. Thus, the model suggests that step rate tends to primarily modulate the magnitude of contact pressure and contact area, while vastus medialis strengthening has the potential to alter mediolateral pressure locations. These results are relevant to consider in the design of interventions used to prevent or treat patellofemoral pain in runners.

  3. An Acute Bout of Quadriceps Muscle Stretching has no Influence on Knee Joint Proprioception.

    PubMed

    Torres, Rui; Duarte, José Alberto; Cabri, Jan Mh

    2012-10-01

    The main objective of this study was to determine if an acute bout of static stretching of the quadriceps muscle affects the sense of joint position, the threshold to detect passive movement, and the sense of force. Thirty young, healthy men (age : 22.1 ± 2.7 years) were randomly divided into two groups. The Stretching Group (n=15) underwent stretching of the dominant quadriceps muscle, which comprised ten passive stretches lasting 30 seconds each, while the Control Group (n=15) remained seated for the same length of time. A repeated-measures analysis of variance was used to establish intragroup differences over time, and an independent sample t-test was used to compare the dependent variables between groups at each moment. None of the measurements revealed any significant change between both groups in each assessment moment or between moments within groups (p>0.05). This study demonstrated that static quadriceps muscle stretching has no effect on the sense of knee joint position, threshold to detect passive movement, and force sense, suggesting that stretching does not have appreciable effect on the spindle firing characteristics and tendon organs activation.

  4. [Paragliding-associated bilateral partial rupture of the rectus femoris muscle].

    PubMed

    Schulze Bertelsbeck, D; Veelken, D

    2004-12-01

    Pain in the thigh or groin due to a rupture of the rectus femoris muscle is rather uncommon. We report on a patient with a bilateral rupture of the rectus femoris muscle that occurred due to a landing maneuver while para-gliding. The diagnosis was confirmed by ultrasound and MRI. Additionally, an old unilateral anterior cruciate ligament rupture was present. As a functional deficit of the quadriceps muscle could not be observed, a primarily conservative treatment seems to be appropriate.

  5. Influence of Anterior Cruciate Ligament Tear on Thigh Muscle Strength and Hamstring-to-Quadriceps Ratio: A Meta-Analysis

    PubMed Central

    Ahn, Sung-Eun; Park, Min-Ji; Lee, Dae-Hee

    2016-01-01

    Theoretical compensation after anterior cruciate ligament (ACL) tear could cause quadriceps weakness and hamstring activation, preventing anterior tibial subluxation and affecting the expected hamstring-to-quadriceps ratio. Although quadriceps weakness often occurs after ACL tears, it remains unclear whether hamstring strength and hamstring-to-quadriceps ratio increase in ACL deficient knees. This meta-analysis compared the isokinetic muscle strength of quadriceps and hamstring muscles, and the hamstring-to-quadriceps ratio, of the injured and injured limbs of patients with ACL tears. This meta-analysis included all studies comparing isokinetic thigh muscle strengths and hamstring-to-quadriceps ratio in the injured and uninjured legs of patients with ACL tear, without or before surgery. Thirteen studies were included in the meta-analysis. Quadriceps and hamstring strengths were 22.3 N∙m (95% CI: 15.2 to 29.3 N∙m; P<0.001) and 7.4 N∙m (95% CI: 4.3 to 10.5 N∙m; P<0.001) lower, respectively, on the injured than on the uninjured side. The mean hamstring-to-quadriceps ratio was 4% greater in ACL deficient than in uninjured limbs (95% CI: 1.7% to 6.3%; P<0.001). Conclusively, Decreases were observed in both the quadriceps and hamstring muscles of patients with ACL tear, with the decrease in quadriceps strength being 3-fold greater. These uneven reductions slightly increase the hamstring-to-quadriceps ratio in ACL deficient knees. PMID:26745808

  6. Influence of Anterior Cruciate Ligament Tear on Thigh Muscle Strength and Hamstring-to-Quadriceps Ratio: A Meta-Analysis.

    PubMed

    Kim, Hyun-Jung; Lee, Jin-Hyuck; Ahn, Sung-Eun; Park, Min-Ji; Lee, Dae-Hee

    2016-01-01

    Theoretical compensation after anterior cruciate ligament (ACL) tear could cause quadriceps weakness and hamstring activation, preventing anterior tibial subluxation and affecting the expected hamstring-to-quadriceps ratio. Although quadriceps weakness often occurs after ACL tears, it remains unclear whether hamstring strength and hamstring-to-quadriceps ratio increase in ACL deficient knees. This meta-analysis compared the isokinetic muscle strength of quadriceps and hamstring muscles, and the hamstring-to-quadriceps ratio, of the injured and injured limbs of patients with ACL tears. This meta-analysis included all studies comparing isokinetic thigh muscle strengths and hamstring-to-quadriceps ratio in the injured and uninjured legs of patients with ACL tear, without or before surgery. Thirteen studies were included in the meta-analysis. Quadriceps and hamstring strengths were 22.3 N∙m (95% CI: 15.2 to 29.3 N∙m; P<0.001) and 7.4 N∙m (95% CI: 4.3 to 10.5 N∙m; P<0.001) lower, respectively, on the injured than on the uninjured side. The mean hamstring-to-quadriceps ratio was 4% greater in ACL deficient than in uninjured limbs (95% CI: 1.7% to 6.3%; P<0.001). Conclusively, Decreases were observed in both the quadriceps and hamstring muscles of patients with ACL tear, with the decrease in quadriceps strength being 3-fold greater. These uneven reductions slightly increase the hamstring-to-quadriceps ratio in ACL deficient knees.

  7. [Quadratus femoris muscle tear].

    PubMed

    Domínguez-Gasca, L G; Alcocer-Maldonado, J L; Magaña-Reyes, J; Domínguez-Carrillo, L G

    2016-01-01

    Quadratus femoris tear is an uncommon injury that usually cause hip pain, it incidence is unknown. The patient can suffer of posterior gluteal pain or groin pain or both, which makes accurate diagnosis difficult, because the differential diagnosis of hip pain is broad. A 65 years old male, with gluteal and groin pain presented during tennis; evaluated by neurologist with lumbosacral magnetic resonance imaging (MRI) (normal) and referred to physical therapy, a pelvic MRI was required, finding an unsuspected quadratus femoris tear. MRI with its superior soft-tissue resolution and multiplanar capability is an excellent adjunct to physical examination because it shows the anatomic location of the abnormality, aiding the clinician to make unsuspected diagnoses.

  8. Quadriceps and Hamstrings Coactivation During Common Therapeutic Exercises

    PubMed Central

    Begalle, Rebecca L.; DiStefano, Lindsay J.; Blackburn, Troy; Padua, Darin A.

    2012-01-01

    Context Anterior tibial shear force and knee valgus moment increase anterior cruciate ligament (ACL) loading. Muscle coactivation of the quadriceps and hamstrings influences anterior tibial shear force and knee valgus moment, thus potentially influencing ACL loading and injury risk. Therefore, identifying exercises that facilitate balanced activation of the quadriceps and hamstrings might be beneficial in ACL injury rehabilitation and prevention. Objective To quantify and compare quadriceps with hamstrings coactivation electromyographic (EMG) ratios during commonly used closed kinetic chain exercises. Design Cross-sectional study. Setting Research laboratory. Patients or Other Participants Twenty-seven healthy, physically active volunteers (12 men, 15 women; age = 22.1 ± 3.1 years, height = 171.4 ± 10 cm, mass = 72.4 ± 16.7 kg). Intervention(s) Participants completed 9 separate closed chain therapeutic exercises in a randomized order. Main Outcome Measure(s) Surface electromyography quantified the activity level of the vastus medialis (VM), vastus lateralis (VL), medial hamstrings (MH), and biceps femoris (BF) muscles. The quadriceps-to-hamstrings (Q:H) coactivation ratio was computed as the sum of average quadriceps (VM, VL) EMG amplitude divided by the sum of average hamstrings (MH, BF) EMG amplitude for each trial. We used repeated-measures analyses of variance to compare Q:H ratios and individual muscle contributions across exercises (α = .05), then used post hoc Tukey analyses. Results We observed a main effect for exercise (F3,79 = 22.6, P < .001). The post hoc Tukey analyses revealed smaller Q:H ratios during the single-limb dead lift (2.87 ± 1.77) than the single-limb squat (5.52 ± 2.89) exercise. The largest Q:H ratios were observed during the transverse-lunge (7.78 ± 5.51, P < .001), lateral-lunge (9.30 ± 5.53, P < .001), and forward-lunge (9.70 ± 5.90, P < .001) exercises. Conclusions The most balanced (smallest) coactivation ratios were

  9. Selective hypertrophy of the quadriceps musculature after 14 weeks of isokinetic and conventional resistance training.

    PubMed

    Matta, Thiago Torres; Nascimento, Francisco Xavier; Trajano, Gabriel S; Simão, Roberto; Willardson, Jeffrey Michael; Oliveira, Liliam Fernandes

    2017-03-01

    One of the fundamental adaptations observed with resistance training (RT) is muscle hypertrophy. Conventional and isokinetic machines provide different forms of mechanical stress, and it is possible that these two training modes could promote differing degrees of hypertrophic adaptations. There is a lack of data comparing the selective hypertrophy of the quadriceps musculature after training with a conventional knee extension machine versus an isokinetic machine. The purpose of this study was to evaluate the selective hypertrophy of the quadriceps musculature and knee extension maximal isometric torque after 14 weeks of conventional versus isokinetic RT. Thirty-five men were assigned to three groups: control group and training groups (conventional and isokinetic) performed three sets of unilateral knee extensions per session with a progressive loading scheme twice a week. Prior to and following the intervention, maximal isometric knee extensor torque was measured using an isokinetic dynamometer, and muscle thickness (MT) of quadriceps femoris muscles was assessed via ultrasound. The results indicated non-uniform changes in MT between the muscles that comprise the quadriceps femoris group. For the conventional group, significantly greater increases in rectus femoris thickness were evident versus all other quadriceps muscles (14%). For the isokinetic group, increases in RF thickness (11%) were significantly greater in comparison with the vastus intermedius only. Although the muscle thickness did not increase for all the quadriceps femoris muscles, the relative rectus femoris adaptation suggested a selective hypertrophy favouring this portion.

  10. Rectus Femoris Tendon Calcification

    PubMed Central

    Zini, Raul; Panascì, Manlio; Papalia, Rocco; Franceschi, Francesco; Vasta, Sebastiano; Denaro, Vincenzo

    2014-01-01

    Background: Since it was developed, hip arthroscopy has become the favored treatment for femoroacetabular impingement. Due to recent considerable improvements, the indications for this technique have been widely extended. Injuries of the rectus femoris tendon origin, after an acute phase, could result in a chronic tendinopathy with calcium hydroxyapatite crystal deposition, leading to pain and loss of function. Traditionally, this condition is addressed by local injection of anesthetic and corticosteroids or, when conservative measures fail, by open excision of the calcific lesion by an anterior approach. Purpose: To assess whether arthroscopic excision of calcification of the proximal rectus is a safe and effective treatment. Study Design: Case series; Level of evidence, 4. Methods: Outcomes were studied from 6 top amateur athletes (age range, 30-43 years; mean, 32.6 years) affected by calcification of the proximal rectus who underwent arthroscopic excision of the calcification. Patients were preoperatively assessed radiographically, and diagnosis was confirmed by a 3-dimensional computed tomography scan. To evaluate the outcome, standardized hip rating scores were used pre- and postoperatively (at 6 and 12 months): the Hip disability and Osteoarthritis Outcome Score, Oxford Hip Score, and Modified Harris Hip Score. Moreover, visual analog scales (VAS) for pain, sport activity level (SAL), and activities of daily living (ADL) were also used. Results: One year after surgery, all patients reported satisfactory outcomes, with 3 of 6 rating their return-to-sport level as high as preinjury level, and the remaining 3 with a percentage higher than 80%. Five patients ranked their ability to carry on daily activities at 100%. Statistical analysis showed significant improvement of the Oxford Hip Score, the Modified Harris Hip Score, and all 3 VAS subscales (pain, SAL, and ADL) from pre- to latest postoperative assessment (P < .05). Conclusion: Arthroscopic excision of

  11. Isokinetic hamstrings-to-quadriceps peak torque ratio: the influence of sport modality, gender, and angular velocity.

    PubMed

    Andrade, Marilia Dos Santos; De Lira, Claudio Andre Barbosa; Koffes, Fabiana De Carvalho; Mascarin, Naryana Cristina; Benedito-Silva, Ana Amélia; Da Silva, Antonio Carlos

    2012-01-01

    The purpose of this study was to determine differences in hamstrings-to-quadriceps (H/Q) peak torque ratios evaluated at different angular velocities between men and women who participate in judo, handball or soccer. A total of 166 athletes, including 58 judokas (26 females and 32 males), 39 handball players (22 females and 17 males), and 69 soccer players (17 females and 52 males), were evaluated using an isokinetic dynamometer. The H/Q isokinetic peak torque ratios were calculated at angular velocities of 1.05 rad · s⁻¹ and 5.23 rad · s⁻¹. In the analysis by gender, female soccer players produced lower H/Q peak torque ratios at 1.05 rad · s⁻¹ than males involved in the same sport. However, when H/Q peak torque ratio was assessed at 5.23 rad · s⁻¹, there were no significant differences between the sexes. In the analysis by sport, there were no differences among females at 1.05 rad · s⁻¹. In contrast, male soccer players had significantly higher H/Q peak torque ratios than judokas (66 ± 12% vs. 57 ± 14%, respectively). Female handball players produced significantly lower peak torque ratios at 5.23 rad · s⁻¹ than judokas or soccer players, whereas males presented no ratio differences among sports At 5.23 rad · s⁻¹. In the analysis by velocity, women's muscular ratios assessed at 1.05 rad · s⁻¹ were significantly lower than at 5.23 rad · s⁻¹ for all sports; among men, only judokas presented lower ratios at 1.05 rad · s⁻¹ than at 5.23 rad · s⁻¹. The present results suggest that sport modality and angular velocity influence the isokinetic strength profiles of men and women.

  12. Clinical anatomy and mechanical tensile properties of the rectus femoris tendon

    PubMed Central

    Zhu, Xing-Fei; Zhang, Xin-Chao

    2015-01-01

    Purpose: We aimed to provide anatomical data and mechanical tensile properties for the rectus femoris tendon to determine if it is a feasible substitute for the anterior cruciate ligament during knee joint reconstruction. Methods: The length and width of the quadriceps femoris tendon were measured from ten adult cadavers (20 knees; age =48±2 years). The anatomic features of the patellar insertion on the quadriceps femoris tendon were also documented. The rectus femoris tendon and anterior cruciate ligament were harvested from an additional five fresh specimens (10 knees; age =41±3 years). To minimize dehydration, each specimen was wrapped in saline-moistened paper towels and stored at -10°C. We imposed tensile stresses on a total of twenty samples in a sample-driven machine at 10 mm/min until the specimens failed. Results: The inserted and discrete widths of the rectus femoris tendon were 3.20±0.33 and 1.28±0.25 cm, respectively. The length of the tendon tissue was 6.96±0.80 cm and the length of mixing zone was 3.81±0.53 cm. The average thickness of the upper pole of the patella was 2.22±0.14 cm. In mechanical tensile properties, the unit modulus and unit maximum load of the rectus femoris tendon were both 63% of the anterior cruciate ligament. Conclusions: Based on its anatomical and mechanical tensile properties, the rectus femoris tendon is a feasible donor site to reconstitute the anterior cruciate ligament. PMID:26885205

  13. Clinical anatomy and mechanical tensile properties of the rectus femoris tendon.

    PubMed

    Zhu, Xing-Fei; Zhang, Xin-Chao

    2015-01-01

    We aimed to provide anatomical data and mechanical tensile properties for the rectus femoris tendon to determine if it is a feasible substitute for the anterior cruciate ligament during knee joint reconstruction. The length and width of the quadriceps femoris tendon were measured from ten adult cadavers (20 knees; age =48±2 years). The anatomic features of the patellar insertion on the quadriceps femoris tendon were also documented. The rectus femoris tendon and anterior cruciate ligament were harvested from an additional five fresh specimens (10 knees; age =41±3 years). To minimize dehydration, each specimen was wrapped in saline-moistened paper towels and stored at -10°C. We imposed tensile stresses on a total of twenty samples in a sample-driven machine at 10 mm/min until the specimens failed. The inserted and discrete widths of the rectus femoris tendon were 3.20±0.33 and 1.28±0.25 cm, respectively. The length of the tendon tissue was 6.96±0.80 cm and the length of mixing zone was 3.81±0.53 cm. The average thickness of the upper pole of the patella was 2.22±0.14 cm. In mechanical tensile properties, the unit modulus and unit maximum load of the rectus femoris tendon were both 63% of the anterior cruciate ligament. Based on its anatomical and mechanical tensile properties, the rectus femoris tendon is a feasible donor site to reconstitute the anterior cruciate ligament.

  14. Postpoliomyelitis muscle weakness: a prospective study of quadriceps strength.

    PubMed

    Munin, M C; Jaweed, M M; Staas, W E; Satinsky, A R; Gutierez, G; Herbison, G J

    1991-09-01

    The objective of this study was to evaluate the presence of progressive postpoliomyelitis muscle weakness (PPMW) in affected individuals 20 to 40 years after the initial polio infection. Over a three-year period, the isometric and isokinetic strength of the quadriceps femoris muscle was studied in seven symptomatic patients with previous poliomyelitis (mean = 38.3 years from infection) to determine if quadriceps strength decreased during the three years. Each patient had a quadriceps affected by polio on one side and a clinically nonaffected quadriceps on the contralateral limb. The maximal isometric force and the peak isokinetic force of the affected quadriceps (AQ) and nonaffected quadriceps (NQ) muscles were tested on a computerized isokinetic dynamometer machine at six-month intervals. Isometric force increased significantly, by 29% per year (p less than .02) in the AQ and by 14% per year (p less than .05) in the NQ. Paired analysis to determine the change in strength between the affected and nonaffected muscles for the isometric data showed a mean nonsignificant increase in the AQ of 14% per year (p = .01). The change in peak isokinetic force demonstrated a significant increase in the AQ of 35% per year (p less than .05); whereas, the NQ peak isokinetic force increased 15% per year which was not statistically significant. Paired analysis to determine the change in strength between the affected and nonaffected muscles for the isokinetic data showed a nonsignificant relative increase in the AQ of 20% per year (p less than .06).(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Quadriceps muscle use in the flywheel and barbell squat.

    PubMed

    Norrbrand, Lena; Tous-Fajardo, Julio; Vargas, Roberto; Tesch, Per A

    2011-01-01

    Resistance exercise has been proposed as an aid to counteract quadriceps muscle atrophy in astronauts during extended missions in orbit. While space authorities have advocated the squat exercise should be prescribed, no exercise system suitable for in-flight use has been validated with regard to quadriceps muscle use. We compared muscle involvement in the terrestrial "gold standard" squat using free weights and a nongravity dependent flywheel resistance exercise device designed for use in space. The subjects were 10 strength-trained men who performed 5 sets of 10 repetitions using the barbell squat (BS; 10 repetition maximum) or flywheel squat (FS; each repetition maximal), respectively. Functional magnetic resonance imaging (MRI) and surface electromyography (EMG) techniques assessed quadriceps muscle use. Exercise-induced contrast shift of MR images was measured by means of transverse relaxation time (T2). EMG root mean square (RMS) was measured during concentric (CON) and eccentric (ECC) actions and normalized to EMG RMS determined during maximal voluntary contraction. The quadriceps muscle group showed greater exercise-induced T2 increase following FS compared with BS. Among individual muscles, the rectus femoris displayed greater T2 increase with FS (+24 +/- 14%) than BS (+8 +/- 4%). Normalized quadriceps EMG showed no difference across exercise modes. Collectively, the results of this study suggest that quadriceps muscle use in the squat is comparable, if not greater, with flywheel compared with free weight resistance exercise. Data appear to provide support for use of flywheel squat resistance exercise as a countermeasures adjunct during spaceflight.

  16. Proximal rectus femoris avulsion in an elite, olympic-level sprinter.

    PubMed

    Langer, Phillip R; Selesnick, Harlan

    2010-11-01

    Quadriceps injuries, ranging from simple strains to disabling muscle ruptures, are common athletic injuries. The rectus femoris is the most commonly injure portion of the quadriceps musculature. This article is, to our knowledge, the first report of a proximal rectus femoris avulsion in an elite, Olympic-level 100-meter sprinter, acutely managed with surgical repair. Several key factors must be considered and carefully assessed when determining the appropriate course of management (ie, deciding between operative and nonoperative treatment): amount of distal retraction of the tendon, severity of associated soft-tissue trauma, physical examination, and postoperative goals (eg, return to elite-level competitive sports involving running or kicking vs resuming basic activities of daily living). We believe that these factors in our elite, high-performance athlete dictated an operative course of management.

  17. The Effects of Knee Joint Effusion on Quadriceps Electromyography During Jogging

    PubMed Central

    Torry, Michael R.; Decker, Michael J.; Millett, Peter J.; Steadman, J. Richard; Sterett, William I.

    2005-01-01

    To investigate and describe the influence of intra-articular effusion on knee joint kinematics and electromyographic (EMG) profiles during jogging. Thirteen individuals underwent a 20 cc 0.9% saline insufflation of the knee joint capsule and completed 8 jogging trials. Stance phase, sagittal plane knee joint kinematics and thigh muscular EMG profiles were compared pre- and post-insufflation utilizing a paired t-test ( = 0.05). Mild knee effusion caused a reduction in vastus medialis (p = 0.005) and lateralis (p = 0.006) EMG activity. The rectus femoris, biceps femoris and medial hamstring muscles did not exhibit changes due to this protocol. There were no changes in the sagittal plane knee joint kinematic pattern. Twenty cc effusion can cause quadriceps inhibition in the vastus medialis and the vastus lateralis in otherwise healthy individuals during jogging. This study provides baseline data for the effects of mild knee joint effusion on thigh musculature during jogging. Key Points 20 cc of knee effusion can cause vastus medialis and lateralis inhibition as noted by decreases in EMG amplitude. This effusion does not appear to alter sagittal plane knee joint kinematics during jogging. This finding if different from previous work investigating knee joint kinematic changes during a less dynamic activity (gait) with 20 cc of effusion. PMID:24431955

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

    PubMed

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

    2016-12-08

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

  19. Continuous Femoral Nerve Blocks: Varying Local Anesthetic Delivery Method (Bolus versus Basal) to Minimize Quadriceps Motor Block while Maintaining Sensory Block

    PubMed Central

    Charous, Matthew T.; Madison, Sarah J.; Suresh, J.; Sandhu, NavParkash S.; Loland, Vanessa J.; Mariano, Edward R.; Donohue, Michael C.; Dutton, Pascual H.; Ferguson, Eliza J.; Ilfeld, Brian M.

    2011-01-01

    Background Whether the method of local anesthetic administration for continuous femoral nerve blocks —basal infusion versus repeated hourly bolus doses —influences block effects remains unknown. Methods Bilateral femoral perineural catheters were inserted in volunteers (n = 11). Ropivacaine 0.1% was administered through both catheters concurrently: a 6-h continuous 5 ml/h basal infusion on one side and 6 hourly bolus doses on the contralateral side. The primary endpoint was the maximum voluntary isometric contraction (MVIC) of the quadriceps femoris muscle at Hour 6. Secondary end points included quadriceps MVIC at other time points, hip adductor MVIC, and cutaneous sensation 2 cm medial to the distal quadriceps tendon in the 22 h following local anesthetic administration initiation. Results Quadriceps MVIC for limbs receiving 0.1% ropivacaine as a basal infusion declined by a mean (SD) of 84% (19) compared with 83% (24) for limbs receiving 0.1% ropivacaine as repeated bolus doses between baseline and Hour 6 (paired t test P = 0.91). Intrasubject comparisons (left vs. right) reflected a lack of difference as well: the mean basal-bolus difference in quadriceps MVIC at Hour 6 was −1.1% (95% CI −22.0 to 19.8%). The similarity did not reach our a priori threshold for concluding equivalence, which was the 95% CI falling within ± 20%. There were similar minimal differences in the secondary endpoints during local anesthetic administration. Conclusions This study did not find evidence to support the hypothesis that varying the method of local anesthetic administration —basal infusion versus repeated bolus doses —influences continuous femoral nerve block effects to a clinically significant degree. PMID:21394001

  20. Muscle activation of the quadriceps and hamstrings during incremental running.

    PubMed

    Camic, Clayton L; Kovacs, Attila J; Enquist, Evan A; McLain, Trisha A; Hill, Ethan C

    2015-12-01

    The aim of this study was to determine the patterns of responses for the electromyographic (EMG) amplitude vs. oxygen uptake ( V̇O2 ) relationships from muscles of the quadriceps femoris and hamstrings during incremental treadmill running. Twelve men volunteered to perform an incremental test to exhaustion while EMG signals were recorded from the vastus lateralis, vastus medialis, biceps femoris, and semitendinosus muscles. Polynomial regression analyses were used to determine the best model fit for the EMG amplitude vs. V̇O2 relationships. There were significant (P < 0.05) increases in EMG amplitude across V̇O2 for the vastus lateralis (quadratic, R = 0.995), vastus medialis (quadratic, R = 0.997), biceps femoris (cubic, R = 0.999), and semitendinosus (linear, R = 0.992) muscles as well as the hamstrings-to-quadriceps ratio (cubic, R = 0.999). These findings indicate that the patterns of responses for muscle activation vs. exercise intensity appear to be unique among muscles of the thigh. © 2015 Wiley Periodicals, Inc.

  1. Surgical Management of Rectus Femoris Avulsion Among Professional Soccer Players

    PubMed Central

    Sonnery-Cottet, Bertrand; Barbosa, Nuno Camelo; Tuteja, Sanesh; Gardon, Roland; Daggett, Matt; Monnot, Damien; Kajetanek, Charles; Thaunat, Mathieu

    2017-01-01

    Background: Rectus femoris injuries are common among athletes, especially in kicking sports such as soccer; however, proximal rectus femoris avulsions in athletes are a relatively rare entity. Purpose/Hypothesis: The purpose of this study was to describe and report the results of an original technique of surgical excision of the proximal tendon remnant followed by a muscular suture repair. Our hypothesis was that this technique limits the risk of recurrence in high-level athletes and allows for rapid recovery without loss of quadriceps strength. Study Design: Case series; Level of evidence, 4. Methods: Our retrospective series included 5 players aged 31.8 ± 3.9 years with acute proximal rectus femoris avulsion injuries who underwent a surgical resection of the proximal tendon between March 2012 and June 2014. Four of these players had recurrent rectus femoris injuries in the 9 months before surgery, while 1 player had surgery after a first injury. Mean follow-up was 18.2 ± 12.6 months, and minimum follow-up was 9 months. We analyzed the age, sex distribution, physical examination outcomes, type and mechanism of injury, diagnosis, treatment and complications during surgery, postoperative follow-up, and time to return to play. The Lower Extremity Functional Scale (LEFS) and Marx scores were obtained at 3-month follow-up, and isokinetic tests were performed before return to sports. A telephone interview was completed to determine the presence of recurrence at an average follow-up of 18.2 months. Results: At 3-month follow-up, all patients had Marx activity scores of 16 and LEFS scores of 80. Return to the previous level of play occurred at a mean of 15.8 ± 2.6 weeks after surgery, and none of the athletes suffered a recurrence. Isokinetic test results were comparable between both sides. Conclusion: The surgical treatment of proximal rectus femoris avulsions, consisting of resection of the tendinous part of the muscle, is a reliable and safe technique allowing a

  2. A dynamic model of quadriceps and hamstrings function.

    PubMed

    Frigo, C; Pavan, E E; Brunner, R

    2010-01-01

    The mechanical effect of hamstrings and quadriceps contractions on hip and knee joint motion was investigated using a dynamic model of the musculoskeletal system. The model consisted of 13 anatomically linked segments. The geometry of bones, joints, and muscle attachments was derived from magnetic resonance imaging of a healthy adult. The knee joint was represented by a crossing bars linkage to simulate cruciate ligament function, and muscles were represented by spring actuators. The effects of hamstring and quadriceps contractions, in various combinations, were tested on different configurations of hip and knee joint position in the absence of gravity. In the standing posture, with the foot free to move and the pelvis fixed in space, the effect of semimembranosus (SM) contraction was hip and knee flexion. If the foot was fixed to the ground, SM contraction produced hip extension and knee flexion. The addition of quadriceps contraction reduced or abolished the knee flexion and enhanced hip extension. In all other simulations, SM alone produced knee flexion and hip extension and the combination of SM with vastus (VA) and rectus femoris (RF) contractions resulted in knee extension and enhanced hip extension. Our findings suggest that co-contraction of quadriceps and hamstrings may be a strategy to increase the hip extension function of the hamstrings.

  3. The effect of taping, quadriceps strengthening and stretching prescribed separately or combined on patellofemoral pain.

    PubMed

    Mason, Marjon; Keays, Susan L; Newcombe, Peter A

    2011-06-01

    Quadriceps strengthening, quadriceps stretching and patellar taping are commonly prescribed together for patellofemoral pain patients. This study aimed to examine the effectiveness of each of these techniques in isolation for one week and in combination for one week. A prospective double-blind randomized control study was designed involving 41 subjects with 60 knees diagnosed with patellofemoral pain. The knees were randomized in onto one of four groups (n = 15): infrapatellar taping, quadriceps strengthening, quadriceps stretching and control. The taping was worn continually for the week; the strengthening group followed a programme of non-weight-bearing terminal range quadriceps exercises, the stretching group performed rectus femoris stretches. The control group did not receive treatment. All subjects received advice. Seven pre- and post-treatment measures included isokinetic quadriceps strength, quadriceps length, pain measured during four activities and maximum eccentric, posturally controlled, pain-free knee flexion angle during a step-down. Results showed significant changes over time (p < 0.01) in two out of seven measures for the taping group, in five out of seven for the strengthening group and five out of seven for the stretching group and none in the control group. When the three modalities were combined for one week, (n = 60) all seven measures improved significantly (p < 0.01). In isolation, quadriceps stretching and quadriceps strengthening resulted in more improvements than taping. Combining these treatments is recommended as the initial approach to treating patellofemoral pain but further individualized more functional, global treatment is essential. Copyright © 2010 John Wiley & Sons, Ltd.

  4. Quadriceps and hamstrings prelanding myoelectric activity during landing from different heights among male and female athletes.

    PubMed

    de Britto, Morgana Alves; Carpes, Felipe P; Koutras, Georgios; Pappas, Evangelos

    2014-08-01

    ACL tear is a major concern among athletes, coaches and sports scientists. More than taking the athlete away from training and competition, ACL tear is a risk factor for early-onset of knee osteoarthritis, and, therefore addressing strategies to avoid such injury is pertinent not only for competitive athletes, but for all physically active subjects. Imbalances in the prelanding myoelectric activity of the hamstrings and quadriceps muscles have been linked to ACL injuries. We investigated the effect of landing from different heights on prelanding myoelectric activity of the hamstrings and quadriceps muscles in recreational athletes. Thirty recreational athletes (15 male and 15 female) performed three bilateral drop jumps from two different heights; 20cm and 40cm while myoelectric activity of the vastus medialis, rectus femoris, biceps femoris and medial hamstrings were collected. When increasing the height of drop landing tasks prelanding normalized myoelectric activity of the quadriceps was increased by 15-20% but no significant changes were found for the hamstrings. Female athletes exhibited higher activity of the medial hamstrings compared to their male counterparts. We concluded that increasing the height of drop landing tasks is associated with increased myoelectric activity of the quadriceps but not the hamstrings in recreational athletes. These differences in muscle activity may be related to increased risk for ACL injury when the height is increased. Female athletes demonstrated higher recruitment of the medial hamstrings.

  5. Atrophy of the quadriceps muscle in children with a painful hip.

    PubMed

    Robben, S G; Lequin, M H; Meradji, M; Diepstraten, A F; Hop, W C

    1999-09-01

    The objective of this study was to determine the degree of muscle wasting of various components of the quadriceps muscle in children with a painful hip. Between January 1994 and September 1997, 327 consecutive children with a unilateral painful hip and/or limping were evaluated prospectively with ultrasonography. Quadriceps thickness was measured on both sides. Moreover, muscle thickness was measured in 59 control subjects. The patients were divided into eight groups; transient synovitis (n = 134), Perthes' disease (n = 35), slipped capital femoral epiphysis (n = 5), osteomyelitis (n = 4), aspecific synovitis (n = 5), rheumatoid arthritis (n = 3) and miscellaneous (n = 16). In 125 patients, no sonographic and radiological abnormalities were found and during follow-up the symptoms disappeared ('no pathology' group). Ipsilateral muscle wasting was present in all patient groups, whereas the control subjects showed no significant difference in muscle thickness between legs. The degree of muscle wasting was compared between transient synovitis, the 'no pathology' group, Perthes' disease and control subjects. For both quadriceps and vastus intermedius muscles, there was a significant difference between these groups, except between control subjects and the 'no pathology' group. For the rectus femoris muscle, there was a significant difference between these groups, except between transient synovitis and 'no pathology'. Muscle wasting showed a positive correlation with duration of symptoms and pre-existing muscle mass. In conclusion, different diseases show different degrees of muscle wasting, and there are different patterns of muscle wasting of various components of the quadriceps femoris muscle.

  6. Comparison of hamstring-to-quadriceps ratio between accelerating and decelerating sections during squat exercise.

    PubMed

    Yoo, Won-Gyu

    2016-09-01

    [Purpose] The aim of this study was to compare hamstring-to-quadriceps ratio between the accelerating and decelerating sections for anterior cruciate ligament protection during squat exercise. [Subjects and Methods] Nine asymptomatic males were enrolled in this study. The hamstring (medial part) and quadriceps (rectus femoris) muscle activities during squat exercise were measured, and the squat exercises were classified into two sections (accelerating and decelerating) by using an accelerometer. [Results] The hamstring-to-quadriceps ratio was significantly higher in the decelerating section than in the accelerating section during the squat exercise. [Conclusion] Application of an increasing decelerating section strategy during the squat exercise can prevent damage in patients with a weakened anterior cruciate ligament due to sports activities.

  7. Reliability of surface EMG during sustained contractions of the quadriceps.

    PubMed

    Mathur, S; Eng, J J; MacIntyre, D L

    2005-02-01

    The purpose of this study was to determine test-retest reliability for median frequency (MDF) and amplitude of surface EMG during sustained fatiguing contractions of the quadriceps. Twenty-two healthy subjects (11 males and 11 females) were tested on two days held one week apart. Surface EMG was recorded from rectus femoris (RF), vastus lateralis (VL) and vastus medialis (VM) during sustained isometric contractions at 80% and 20% of maximal voluntary contraction (MVC) held to exhaustion. Quadriceps fatigue was described using four measures for both MDF and amplitude of EMG: initial, final, normalized final and slope. For both MDF and amplitude, the initial, final and normalized EMG showed moderate to high reliability for all three muscle groups at both contraction levels (ICC=0.59-0.88 for MDF; ICC=0.58-0.99 for amplitude). Slope of MDF and amplitude was associated with a large degree of variability and low ICCs for the 80% but not the 20% MVC. MDF and amplitude of EMG during sustained contractions of the quadriceps are reproducible; normalized final values of MDF and amplitude show better reliability than slope.

  8. Recruitment of fibre types and quadriceps muscle portions during repeated, intense knee-extensor exercise in humans.

    PubMed

    Krustrup, Peter; Söderlund, Karin; Mohr, Magni; González-Alonso, José; Bangsbo, Jens

    2004-10-01

    To investigate recruitment of slow-twitch (ST) and fast-twitch (FT) muscle fibres, as well as the involvement of the various quadriceps femoris muscle portions during repeated, intense, one-legged knee-extensor exercise, 12 healthy male subjects performed two 3-min exercise bouts at approximately 110% maximum thigh O2 consumption (EX1 and EX2) separated by 6 min rest. Single-fibre metabolites were determined in successive muscle biopsies obtained from the vastus lateralis muscle (n = 6) and intra-muscular temperatures were continuously measured at six quadriceps muscle sites (n = 6). Creatine phosphate (CP) had decreased (P < 0.05) by 27, 73 and 88% in ST fibres and 25, 71 and 89% in FT fibres after 15 and 180 s of EX1 and after 180 s of EX2, respectively. CP was below resting mean-1 SD in 15, 46, 84 and 100% of the ST fibres and 9, 48, 85 and 100% of the FT fibres at rest, after 15 and 180 s of EX1 and after 180 s of EX2, respectively. A significant muscle temperature increase (deltaTm) occurred within 2-4 s at all quadriceps muscle sites. DeltaTm varied less than 10% between sites during EX1, but was 23% higher (P < 0.05) in the vastus lateralis than in the rectus femoris muscle during EX2. DeltaTm in the vastus lateralis was 101 and 109% of the mean quadriceps value during EX1 and EX2, respectively. We conclude that both fibre types and all quadriceps muscle portions are recruited at the onset of intense knee-extensor exercise, that essentially all quadriceps muscle fibres are activated during repeated intense exercise and that metabolic measurements in the vastus lateralis muscle provide a good indication of the whole-quadriceps muscle metabolism during repeated, intense, one-legged knee-extensor exercise.

  9. Acute effects of static stretching on muscle-tendon mechanics of quadriceps and plantar flexor muscles.

    PubMed

    Bouvier, Tom; Opplert, Jules; Cometti, Carole; Babault, Nicolas

    2017-07-01

    This study aimed to determine the acute effects of static stretching on stiffness indexes of two muscle groups with a contrasting difference in muscle-tendon proportion. Eleven active males were tested on an isokinetic dynamometer during four sessions randomly presented. Two sessions were dedicated to quadriceps and the two others to triceps surae muscles. Before and immediately after the stretching procedure (5 × 30 s), gastrocnemius medialis and rectus femoris fascicle length and myotendinous junction elongation were determined using ultrasonography. Passive and maximal voluntary torques were measured. Fascicle and myotendinous junction stiffness indexes were calculated. After stretching, maximal voluntary torque similarly decreased for both muscle groups. Passive torque significantly decreased on triceps surae and remained unchanged on quadriceps muscles. Fascicle length increased similarly for both muscles. However, myotendinous junction elongation remained unchanged for gastrocnemius medialis and increased significantly for rectus femoris muscle. Fascicle stiffness index significantly decreased on medial gastrocnemius and remained unchanged on rectus femoris muscle. In contrast, myotendinous junction stiffness index similarly decreased on both muscles. Depending on the muscle considered, the present results revealed different acute stretching effects. This muscle dependency appeared to affect primarily fascicle stiffness index rather than the myotendinous junction.

  10. Quadriceps muscle strength in scoliosis.

    PubMed

    Swallow, E B; Barreiro, E; Gosker, H; Sathyapala, S A; Sanchez, F; Hopkinson, N S; Moxham, J; Schols, A; Gea, J; Polkey, M I

    2009-12-01

    Quadriceps muscle weakness is an important component of chronic obstructive pulmonary disease (COPD). We hypothesised that quadriceps weakness would also be a feature of restrictive lung disease due to scoliosis. We studied 10 patients with severe scoliosis (median (interquartile range (IQR)) forced expiratory volume in 1 s (FEV(1))() 35.3 (11)% predicted), 10 patients with severe COPD (FEV(1) 26.5 (9.0)% pred) and 10 healthy age-matched adults. We measured quadriceps strength, exercise capacity and analysed quadriceps muscle biopsies for myosin heavy-chain (MyHC) isoform expression and the presence of oxidative stress. Both groups exhibited quadriceps weakness with median (IQR) maximal voluntary contraction force being 46.0 (17.0) kg, 21.5 (21.0) kg and 31.5 (11.0) kg, respectively (p = 0.02 and 0.04, respectively, for each patient group against controls). Oxidative stress was significantly greater in the quadriceps of both restrictive and COPD patients. The scoliosis patients exhibited a decrease in the proportion of MyHC type I compared with controls; median (IQR) 35.3 (18.5)% compared with 47.7 (9.3)%, p = 0.028. The scoliosis patients also showed an increase in MyHC IIx (26.3 (15.5)% compared with 11.3 (13.0)%, p = 0.01. Quadriceps weakness is a feature of severe scoliosis; the similarities between patients with scoliosis and patients with COPD suggest a common aetiology to quadriceps weakness in both conditions.

  11. Distal Insertions of the Biceps Femoris

    PubMed Central

    Branch, Eric A.; Anz, Adam W.

    2015-01-01

    Background: Avulsion of the biceps femoris from the fibula and proximal tibia is encountered in clinical practice. While the anatomy of the primary posterolateral corner structures has been qualitatively and quantitatively described, a quantitative analysis regarding the insertions of the biceps femoris on the fibula and proximal tibia is lacking. Purpose: To quantitatively assess the insertions of the biceps femoris, fibular collateral ligament (FCL), and anterolateral ligament (ALL) on the fibula and proximal tibia as well as establish relationships among these structures and to pertinent surgical anatomy. Study Design: Descriptive laboratory study. Methods: Dissections were performed on 12 nonpaired, fresh-frozen cadaveric specimens identifying the biceps femoris, FCL, and ALL, and their insertions on the proximal tibia and fibula. The footprint areas, orientations, and distances from relevant osseous landmarks were measured using a 3-dimensional coordinate measurement device. Results: Dissection produced 6 easily identifiable and reproducible anatomic footprints. Tibial footprints included the insertion of the ALL and an insertion of the biceps femoris (TBF). Fibular footprints included the insertion of the FCL, a distal insertion of the biceps femoris (DBF), a medial footprint of the biceps femoris (MBF), and a proximal footprint of the biceps femoris (PBF). The mean area of these footprints (95% CI) was as follows: ALL, 53.0 mm2 (38.4-67.6); TBF, 93.9 mm2 (72.0-115.8); FCL, 86.8 mm2 (72.3-101.2); DBF, 119 mm2 (91.1-146.9); MBF, 46.8 mm2 (29.0-64.5); and PBF, 215 mm2 (192.4-237.5). The mean distance (95% CI) from the Gerdy tubercle to the center of the ALL footprint was 24.3 mm (21.6-27.0) and to the center of the TBF was 22.5 mm (21.0-24.0). The center of the DBF was 8.68 mm (7.0-10.3) from the anterior border of the fibula, the center of the FCL was 14.6 mm (12.5-16.7) from the anterior border of the fibula and 20.7 mm (19.0-22.4) from the tip of the fibular

  12. Contribution of Hamstring Fatigue to Quadriceps Inhibition Following Lumbar Extension Exercise

    PubMed Central

    Hart, Joseph M.; Kerrigan, D. Casey; Fritz, Julie M.; Saliba, Ethan N.; Gansneder, Bruce; Ingersoll, Christopher D.

    2006-01-01

    The purpose of this study was to determine the contribution of hamstrings and quadriceps fatigue to quadriceps inhibition following lumbar extension exercise. Regression models were calculated consisting of the outcome variable: quadriceps inhibition and predictor variables: change in EMG median frequency in the quadriceps and hamstrings during lumbar fatiguing exercise. Twenty-five subjects with a history of low back pain were matched by gender, height and mass to 25 healthy controls. Subjects performed two sets of fatiguing isometric lumbar extension exercise until mild (set 1) and moderate (set 2) fatigue of the lumbar paraspinals. Quadriceps and hamstring EMG median frequency were measured while subjects performed fatiguing exercise. A burst of electrical stimuli was superimposed while subjects performed an isometric maximal quadriceps contraction to estimate quadriceps inhibition after each exercise set. Results indicate the change in hamstring median frequency explained variance in quadriceps inhibition following the exercise sets in the history of low back pain group only. Change in quadriceps median frequency explained variance in quadriceps inhibition following the first exercise set in the control group only. In conclusion, persons with a history of low back pain whose quadriceps become inhibited following lumbar paraspinal exercise may be adapting to the fatigue by using their hamstring muscles more than controls. Key Points A neuromuscular relationship between the lumbar paraspinals and quadriceps while performing lumbar extension exercise may be influenced by hamstring muscle fatigue. QI following lumbar extension exercise in persons with a history of LBP group may involve significant contribution from the hamstring muscle group. More hamstring muscle contribution may be a necessary adaptation in the history of LBP group due to weaker and more fatigable lumbar extensors. PMID:24198683

  13. Neuromuscular performance of maximal voluntary explosive concentric contractions is influenced by angular acceleration.

    PubMed

    Hahn, D; Bakenecker, P; Zinke, F

    2016-12-28

    Torque production during maximal voluntary explosive contractions is considered to be a functionally more relevant neuromuscular measure than steady-state torque, but little is known about accelerated concentric contractions. This study investigated torque, muscle activity, and fascicle behavior during isometric and fast concentric contractions of quadriceps femoris. Ten participants performed maximal voluntary explosive isometric, isovelocity, and additional concentric knee extensions at angular accelerations ranging from 700 to 4000° s(-2) that resulted in an angular velocity of 300° s(-1) at 40° knee flexion. Concentric torque at 40° knee flexion was corrected for inertia, and the corresponding isometric torque was matched to the time when the target knee angle of 40° was reached during concentric contractions. Electromyography of quadriceps femoris and hamstrings and ultrasound of vastus lateralis were measured to determine muscle activity, fascicle length, and fascicle velocity (FV). The faster the acceleration, the more torque was produced during concentric contractions at 40° knee flexion, which was accompanied by a reduction in FV. In comparison with isometric conditions, concentric quadriceps muscle activity was increased and torque during accelerations ≥3000° s(-2) equaled the time-matched isometric torque. Our results provide novel evidence that acceleration influences torque production during maximal voluntary explosive concentric contractions. This is suggested to be due to series elasticity and reduced force depression. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. Pre-freezing raw hams affects quality traits in cooked hams: potential influence of protein oxidation.

    PubMed

    Utrera, M; Armenteros, M; Ventanas, S; Solano, F; Estévez, M

    2012-12-01

    The influence of protein carbonylation and lipid oxidation on colour and texture changes in cooked hams from fresh and pre-frozen (frozen/thawed) raw material was studied. Samples from three muscles, biceps femoris (BF) quadriceps femoris (QF) and semimembranosus (SM) were analysed for the gain of specific protein carbonyls, α-aminoadipic and γ-glutamic semialdehydes, the gain of TBA-RS and their colour and texture properties by instrumental and sensory techniques. The formation of protein carbonyls occurred concomitantly with an intense loss of redness and increase of hardness. Both phenomena were found to be more intense in QF and SM muscles in cooked hams elaborated from frozen material. Lipid oxidation played a negligible role on the impaired quality traits observed in cooked hams as a result of pre-freezing. Plausible mechanisms by which protein carbonylation may be implicated in the loss of quality in cooked hams produced from pre-frozen material are discussed.

  15. Increase in passive muscle tension of the quadriceps muscle heads in jumping athletes with patellar tendinopathy.

    PubMed

    Zhang, Z J; Ng, G Y F; Lee, W C; Fu, S N

    2016-08-19

    To investigate the passive muscle tension of the quadriceps muscle heads in male athletes clinically diagnosed with patellar tendinopathy (PT) with those of healthy controls and explore the interplay between passive muscle tension and patellar tendon stiffness. Between November 2012 and December 2013, 66 male athletes (mean age of 21.1 ± 4.4 years) were examined using supersonic shear wave imaging technology. The passive tension of the vastus lateralis (VL) and rectus femoris (RF) muscles and patellar tendon stiffness were assessed. The shear elastic modulus of the VL muscle was increased by 26.5% (P < 0.001) in the subjects with PT when compared with the controls. Greater passive tension in the VL was associated with higher patellar tendon stiffness (r = 0.38; P = 0.001). The vastus lateralis muscle of the quadriceps shows increase in passive muscle tension in jumping athletes with patellar tendinopathy. These findings suggest that increase in muscle tension is not similar in the individual muscles of the quadriceps muscle. Traditional stretching of the whole quadriceps muscle might not be targeted to the tight muscle heads.

  16. Differential Glucose Uptake in Quadriceps and Other Leg Muscles During One-Legged Dynamic Submaximal Knee-Extension Exercise

    PubMed Central

    Kalliokoski, Kari K.; Boushel, Robert; Langberg, Henning; Scheede-Bergdahl, Celena; Ryberg, Ann Kathrine; Døssing, Simon; Kjær, Andreas; Kjær, Michael

    2011-01-01

    One-legged dynamic knee-extension exercise (DKE) is a widely used model to study the local cardiovascular and metabolic responses to exercise of the quadriceps muscles. In this study, we explored the extent to which different muscles of the quadriceps are activated during exercise using positron emission tomography (PET) determined uptake of [18F]-fluoro-deoxy-glucose (GU) during DKE. Five healthy male subjects performed DKE at 25 W for 35 min and both the contracting and contralateral resting leg were scanned with PET from mid-thigh and distally. On average, exercise GU was the highest in the vastus intermedius (VI) and lowest in the vastus lateralis (VL; VI vs VL, p < 0.05), whereas the coefficient of variation was highest in VL (VL vs VI, p < 0.05). Coefficient of variation between the mean values of the four quadriceps femoris (QF) muscles in the exercising leg was 35 ± 9%. Compared to mean GU in QF (=100%), GU was on average 73% in VL, 84% in rectus femoris, 115% in vastus medialis, and 142% in VI. Variable activation of hamstring muscles and muscles of the lower leg was also observed. These results show that GU of different muscles of quadriceps muscle group as well as between individuals vary greatly during DKE, and suggests that muscle activity is not equal between quadriceps muscles in this exercise model. Furthermore, posterior thigh muscles and lower leg muscles are more active than hitherto thought even during this moderate exercise intensity. PMID:22046164

  17. Differential glucose uptake in quadriceps and other leg muscles during one-legged dynamic submaximal knee-extension exercise.

    PubMed

    Kalliokoski, Kari K; Boushel, Robert; Langberg, Henning; Scheede-Bergdahl, Celena; Ryberg, Ann Kathrine; Døssing, Simon; Kjær, Andreas; Kjær, Michael

    2011-01-01

    One-legged dynamic knee-extension exercise (DKE) is a widely used model to study the local cardiovascular and metabolic responses to exercise of the quadriceps muscles. In this study, we explored the extent to which different muscles of the quadriceps are activated during exercise using positron emission tomography (PET) determined uptake of [(18)F]-fluoro-deoxy-glucose (GU) during DKE. Five healthy male subjects performed DKE at 25 W for 35 min and both the contracting and contralateral resting leg were scanned with PET from mid-thigh and distally. On average, exercise GU was the highest in the vastus intermedius (VI) and lowest in the vastus lateralis (VL; VI vs VL, p < 0.05), whereas the coefficient of variation was highest in VL (VL vs VI, p < 0.05). Coefficient of variation between the mean values of the four quadriceps femoris (QF) muscles in the exercising leg was 35 ± 9%. Compared to mean GU in QF (=100%), GU was on average 73% in VL, 84% in rectus femoris, 115% in vastus medialis, and 142% in VI. Variable activation of hamstring muscles and muscles of the lower leg was also observed. These results show that GU of different muscles of quadriceps muscle group as well as between individuals vary greatly during DKE, and suggests that muscle activity is not equal between quadriceps muscles in this exercise model. Furthermore, posterior thigh muscles and lower leg muscles are more active than hitherto thought even during this moderate exercise intensity.

  18. Lack of effect of superficial heat to the knee on quadriceps function in individuals with quadriceps inhibition.

    PubMed

    Warner, Brandon; Kim, Kyung-Min; Hart, Joseph M; Saliba, Susan

    2013-05-01

    Quadriceps function improves after application of focal joint cooling or transcutaneous electrical nerve stimulation to the knee in patients with arthrogenic muscle inhibition (AMI), yet it is not known whether superficial heat is able to produce a similar effect. To determine quadriceps function after superficial heat to the knee joint in individuals with AMI. Single blinded randomized crossover. Laboratory. 12 subjects (4 female, 8 males; 25.6 ± 7.7 y, 177.2 ± 12.7 cm, 78.4 ± 18.2 kg) with a history of knee-joint pathology and AMI, determined with a quadriceps central activation ratio (CAR) of <90%. 3 treatment conditions for 15 min on separate days: superficial heat using a cervical moist-heat pack (77 °C), sham using a cervical moist pack (room temperature at about 24 °C), and control (no treatment). All subjects received all treatment conditions in a randomized order. Central activation ratio and knee-extension torque during maximal voluntary isometric contraction with the knee flexed to 60° were collected at pre, immediately post, 30 min post, and 45 min posttreatment. Skin temperature of the quadriceps and knee and room temperature were also recorded at the same time points. Three (treatment conditions) by 4 (time) repeated ANOVAs found that there were no significant interactions or main effects in either CAR or knee-extension torque (all P > .05). Skin-temperature 1-way ANOVAs revealed that the skin temperature in the knee during superficial heat was significantly higher than other treatment conditions at all time points (P < .05). Superficial heat to the knee joint using a cervical moist-heat pack did not influence quadriceps function in individuals with AMI in the quadriceps.

  19. Reliability of bedside ultrasound for measurement of quadriceps muscle thickness in critically ill patients with acute kidney injury.

    PubMed

    Sabatino, Alice; Regolisti, Giuseppe; Bozzoli, Laura; Fani, Filippo; Antoniotti, Riccardo; Maggiore, Umberto; Fiaccadori, Enrico

    2016-10-01

    In patients with Acute Kidney Injury there is a lack of nutritional variables that can assess nutritional status, more specifically lean body mass (LBM) and skeletal muscle mass, at the individual level. In this clinical setting, ultrasound (US)) of the quadriceps femoris could represent a widely available, non-invasive, affordable, and reliable tool to evaluate skeletal muscle. We performed a cross-sectional observational study in adult critically ill patients with KDIGO stage 3 AKI on dialysis. Quadriceps rectus femoris and vastus intermedius thickness were measured by two assessors. Intra- and interobserver reliability was evaluated using the intraclass correlation coefficient (ICC). The same US measures were obtained before and after dialysis. We enrolled 34 patients, 22 (65%) were male and the mean APACHE II score was 22.7 (±5.6). In the intraobserver reliability study, assessor 1 performed 288 paired measurements and assessor 2 performed 430 paired measurements in 34 patients, with an ICC equal to 0.99 and 1.00, respectively. There were 238 paired measurements (34 patients) in the interobserver reliability study, with an ICC = 0.92. No difference was found in the measurements obtained before and after dialysis (11.5 (4.2) vs 11.4 (4.1) mm, P = 0.2498), independently from acute body weight changes due to fluid removal. In patients with AKI, US of quadriceps femoris could represent a simple, accurate, and non-invasive method to evaluate quantitative changes in skeletal muscle. Copyright © 2016 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  20. Obesity is associated with prolonged activity of the quadriceps and gastrocnemii during gait.

    PubMed

    Amiri, P; Hubley-Kozey, C L; Landry, S C; Stanish, W D; Astephen Wilson, J L

    2015-12-01

    To examine the effect of obesity and its potential interaction with knee OA presence on the electromyography patterns of the major knee joint periarticular muscles during walking. One hundred and eighteen asymptomatic adults and 177 adults with moderate knee osteoarthritis were subdivided into categories of healthy weight (n = 77; 20 kg/m(2) < BMI < 25 kg/m(2)), overweight (n = 117; 25 kg/m(2) ⩽ BMI < 30 kg/m(2)), and obese (n = 101; BMI ⩾ 30 kg/m(2) based on their body mass index (BMI). All individuals underwent a three-dimensional gait analysis. Surface electromyograms from the lateral and medial gastrocnemii, lateral and medial hamstrings, vastus lateralis, vastus medialis, and rectus femoris were recorded during self-selected speed walking. Principal component analysis was used to extract major features of amplitude and temporal pattern variability from the electromyograms of each muscle group (gastrocnemii, quadriceps, hamstrings separately). Analysis of variance models tested for main BMI category effects and interaction effects for these features (α = 0.05). Statistically significant BMI category (i.e. obesity) effects were found for features that described more prolonged activations of the gastrocnemii and quadriceps muscles during the stance phase of gait with obesity (P < 0.05). Obesity was associated with prolonged activation of quadriceps and gastrocnemii, which can result in prolonged knee joint contact loading, and thereby may contribute to the predisposition of knee OA development and progression in obese individuals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. A Novel Noninvasive Method for Measuring Fatigability of the Quadriceps Muscle in Noncooperating Healthy Subjects

    PubMed Central

    Poulsen, Jesper B.; Rose, Martin H.; Møller, Kirsten; Perner, Anders; Jensen, Bente R.

    2015-01-01

    Background. Critical illness is associated with muscle weakness leading to long-term functional limitations. Objectives. To assess the reliability of a novel method for evaluating fatigability of the quadriceps muscle in noncooperating healthy subjects. Methods. On two occasions, separated by seven days, nonvoluntary isometric contractions (twitch and tetanic) of the quadriceps femoris muscle evoked by transcutaneous electrical muscle stimulation were recorded in twelve healthy adults. For tetanic contractions, the Fatigue Index (ratio of peak torque values) and the slope of the regression line of peak torque values were primary outcome measures. For twitch contractions, maximum peak torque and rise time were calculated. Relative (intraclass correlation, ICC3.1) and absolute (standard error of measurement, SEM) reliability were assessed and minimum detectable change was calculated using a 95% confidence interval (MDC95%). Results. The Fatigue Index (ICC3.1, 0.84; MDC95%, 0.12) and the slope of the regression line (ICC3.1, 0.99; MDC95%, 0.03) showed substantial relative and absolute reliability during the first 15 and 30 contractions, respectively. Conclusion. This method for assessing fatigability of the quadriceps muscle produces reliable results in healthy subjects and may provide valuable data on quantitative changes in muscle working capacity and treatment effects in patients who are incapable of producing voluntary muscle contractions. PMID:26266252

  2. Effects of Quadriceps Muscle Fatigue on Stiff-Knee Gait in Patients with Hemiparesis

    PubMed Central

    Boudarham, Julien; Roche, Nicolas; Pradon, Didier; Delouf, Eric; Bensmail, Djamel; Zory, Raphael

    2014-01-01

    The relationship between neuromuscular fatigue and locomotion has never been investigated in hemiparetic patients despite the fact that, in the clinical context, patients report to be more spastic or stiffer after walking a long distance or after a rehabilitation session. The aim of this study was to evaluate the effects of quadriceps muscle fatigue on the biomechanical gait parameters of patients with a stiff-knee gait (SKG). Thirteen patients and eleven healthy controls performed one gait analysis before a protocol of isokinetic quadriceps fatigue and two after (immediately after and after 10 minutes of rest). Spatiotemporal parameters, sagittal knee and hip kinematics, rectus femoris (RF) and vastus lateralis (VL) kinematics and electromyographic (EMG) activity were analyzed. The results showed that quadriceps muscle weakness, produced by repetitive concentric contractions of the knee extensors, induced an improvement of spatiotemporal parameters for patients and healthy subjects. For the patient group, the increase in gait velocity and step length was associated with i) an increase of sagittal hip and knee flexion during the swing phase, ii) an increase of the maximal normalized length of the RF and VL and of the maximal VL lengthening velocity during the pre-swing and swing phases, and iii) a decrease in EMG activity of the RF muscle during the initial pre-swing phase and during the latter 2/3 of the initial swing phase. These results suggest that quadriceps fatigue did not alter the gait of patients with hemiparesis walking with a SKG and that neuromuscular fatigue may play the same functional role as an anti-spastic treatment such as botulinum toxin-A injection. Strength training of knee extensors, although commonly performed in rehabilitation, does not seem to be a priority to improve gait of these patients. PMID:24718087

  3. Muscle training with repetitive magnetic stimulation of the quadriceps in severe COPD patients.

    PubMed

    Bustamante, Víctor; López de Santa María, Elena; Gorostiza, Amaia; Jiménez, Unai; Gáldiz, Juan B

    2010-02-01

    Previous studies have used electrical neuromuscular stimulation as a physical training method in patients with severe COPD. We introduce the use of the more tolerable magnetic stimulation for the same purpose, investigating the effectiveness of an eight-week protocol. Eighteen patients with severe COPD were randomly assigned to a magnetic stimulation training protocol, n=10, FEV(1)=30% (SD: 7) or to parallel clinical monitoring, control group, n=8, FEV(1)=35% (SD: 8). During eight weeks, patients were stimulated for 15min on each quadriceps femoris, three times per week. Quadriceps muscle strength and endurance measurements, quality-of-life questionnaires (SF36, SGRQ) and a six-minute walking test were all carried out before and after the training period in the stimulated and control subjects. All patients completed the training with increasing intensity of stimulation, displaying a significant improvement in voluntary quadriceps strength (17.5% of the baseline value) and exercise capacity, with a mean increase of 23m in the six-minute walking test. The questionnaire scores showed greater increases in quality-of-life scores in the trained subjects compared to the controls, particularly in the physical function areas: mean increments in SF36 in "physical function": +26, "role limitations due to physical problems": +40 and "vitality": +17.5, while +13, -4 and +1, respectively in controls. Saint George's "Activity" score improved by 19.6 points, for 11.5 in controls. In COPD patients who are limited due to dyspnoea, magnetic neuromuscular stimulation of the quadriceps constitutes a feasible training method for the lower limbs, with positive effects on the muscle function, effort capacity and perception areas.

  4. Bedside Ultrasound Measurement of Rectus Femoris: A Tutorial for the Nutrition Support Clinician

    PubMed Central

    Monares Zepeda, Enrique; Lescas Méndez, Octavio Augusto

    2017-01-01

    Intensive care unit acquired weakness is a long-term consequence after critical illness; it has been related to muscle atrophy and can be considered as one of the main nutritional support challenges at the intensive care unit. Measuring muscle mass by image techniques has become a new area of research for the nutritional support field, extending our knowledge about muscle wasting and the impact of nutritional approaches in the critical care setting, although currently there is no universally accepted technique to perform muscle measurements by ultrasound. Because of this, we present this tutorial for nutrition support clinicians, in order to understand and perform muscle measurements by this reliable, accessible, low-cost, and easy-to-use technique. Reviewing issues such as quadriceps muscle anatomy, correct technique (do's and don'ts), identification of structures, and measurement of the rectus femoris and vastus intermedius muscles helps to acquire the basic concepts of this technique and encouraging more research in this field. PMID:28386479

  5. Proximal Rectus Femoris Avulsion: Ultrasonic Diagnosis and Nonoperative Management

    PubMed Central

    Esser, Stephan; Jantz, David; Hurdle, Mark F.; Taylor, Walter

    2015-01-01

    Objective To present a case of ultrasonic diagnosis and nonoperative management of a complete proximal rectus femoris avulsion in a National Collegiate Athletic Association Division 1 soccer goalkeeper. Background While delivering a goal kick, a previously uninjured 24-year-old collegiate soccer goalkeeper had the sudden onset of right anterior thigh pain. He underwent rehabilitation with rapid resolution of his presenting pain but frequent intermittent recurrence of anterior thigh pain. After he was provided a definitive diagnosis with musculoskeletal ultrasound, he underwent an extended period of rehabilitation and eventually experienced complete recovery without recurrence. Differential Diagnosis Rectus femoris avulsion, rectus femoris strain or partial tear, inguinal hernia, or acetabular labral tear. Treatment Operative and nonoperative options were discussed. In view of the player's recovery, nonoperative options were pursued with a good result. Uniqueness Complete proximal rectus femoris avulsions are rare. Our case contributes to the debate on whether elite-level kicking and running athletes can return to full on-field performance without surgery. Conclusions Complete proximal rectus femoris avulsions can be treated effectively using nonoperative measures with good preservation of function even in the elite-level athlete. In addition, musculoskeletal ultrasound is an excellent tool for on-site evaluation and may help guide prognosis and management. PMID:25978099

  6. Static vs. Dynamic Acute Stretching Effect on Quadriceps Muscle Activity during Soccer Instep Kicking

    PubMed Central

    Amiri-Khorasani, Mohammadtaghi; Kellis, Eleftherios

    2013-01-01

    The purpose of this study was to compare the effects of static and dynamic stretching on quadriceps muscle activation during maximal soccer instep kicking. The kicking motion of twelve male college soccer players (body height: 174.66 ± 5.01 cm; body mass: 72.83 ± 4.83 kg; age: 18.83 ± 0.75 years) was captured using six synchronized high-speed infra-red cameras whilst electromyography (EMG) signals from vastus medialis (VM), lateralis (VL) and rectus femoris (RF) were recorded before and after static or dynamic stretching. Analysis of variance designs showed a higher increase in knee extension angular velocity (9.65% vs. −1.45%, p < 0.001), RF (37.5% vs. −8.33%, p < 0.001), VM (12% vs. −12%, p < 0.018), and VL EMG activity (20% vs. −6.67%, p < 0.001) after dynamic stretching exercises. Based on these results, it could be suggested that dynamic stretching is probably more effective in increasing quadriceps muscle activity and knee extension angular velocity during the final swing phase of a maximal soccer instep kick than static stretching. PMID:24511339

  7. Quadriceps femoris spasticity in children with cerebral palsy: measurement with the pendulum test and relationship with gait abnormalities.

    PubMed

    Szopa, Andrzej; Domagalska-Szopa, Małgorzata; Kidoń, Zenon; Syczewska, Małgorzata

    2014-12-16

    Development of a reliable and objective test of spasticity is important for assessment and treatment of children with cerebral palsy. The pendulum test has been reported to yield reliable measurements of spasticity and to be sensitive to variations in spasticity in these children. However, the relationship between the pendulum test scores and other objective measures of spasticity has not been studied. The present study aimed to assess the effectiveness of an accelerometer-based pendulum test as a measurement of spasticity in CP, and to explore the correlation between the measurements of this test and the global index of deviation from normal gait in in children with cerebral palsy. We studied thirty-six children with cerebral palsy, including 18 with spastic hemiplegia and 18 with spastic diplegia, and a group of 18 typically-developing children. Knee extensor spasticity was assessed bilaterally using the accelerometer-based pendulum test and three-dimensional gait analysis. The Gillette Gait Index was calculated from the results of the gait analysis. The data from the accelerometer-based pendulum test could be used to distinguish between able-bodied children and children with cerebral palsy. Additionally, two of the measurements, first swing excursion and relaxation index, could be used to differentiate the degree of knee extensor spasticity in the children with cerebral palsy. Only a few moderate correlations were found between the Gillette Gait Index and the pendulum test data. This study demonstrates that the pendulum test can be used to discriminate between typically developing children and children with CP, as well as between various degrees of spasticity, such as spastic hemiplegia and spastic diplegia, in the knee extensor muscle of children with CP. Deviations from normal gait in children with CP were not correlated with the results of the pendulum test.

  8. Effects of Exposure to Normobaric Hyperoxia on the Recovery of Local Muscle Fatigue in the Quadriceps Femoris of Young People

    PubMed Central

    Yokoi, Yuka; Yanagihashi, Ryuya; Morishita, Katsuyuki; Fujiwara, Takayuki; Abe, Koji

    2014-01-01

    [Purpose] Acute development of local muscle fatigue and recovery often become large issues on sports fields. This study aimed to identify the effects of normobaric hyperoxia on the recovery of local muscle fatigue. [Subjects] Eleven healthy males participated in this study, and they all completed two protocols in a random order. [Methods] Subjects performed single-leg isometric knee extension at 70% of their maximum voluntary isometric contraction (MVIC) for as long as possible. Each participant was subsequently treated with one of two recovery conditions: 20.9% O2 or 30.0% O2 for 30 minutes. Afterwards, they performed an identical isometric task to measure the extent of their recovery. The following parameters were used to assess the degrees of muscle fatigue: MVIC, endurance time, surface electromyography (sEMG) power spectra, and changes in hemoglobin concentration using near-infrared spectroscopy (NIRS). [Results] The treatment of 30.0% O2 induced a significant recovery rate in MVIC compared to the 20.9% O2. Additionally, the data revealed a significantly higher concentration of total hemoglobin after the 30.0% O2 treatment than after the 20.9% O2 treatment. [Conclusion] The results of this study suggest that recovery from acute muscle fatigue can be better facilitated under 30.0% normobaric hyperoxia than a normoxic condition. Therefore, for cases requiring quicker full recovery, treatment under 30.0% O2 environment for 30 minutes is recommended. PMID:24707107

  9. ‘Serious thigh muscle strains’: beware the intramuscular tendon which plays an important role in difficult hamstring and quadriceps muscle strains

    PubMed Central

    Brukner, Peter; Connell, David

    2016-01-01

    Why do some hamstring and quadriceps strains take much longer to repair than others? Which injuries are more prone to recurrence? Intramuscular tendon injuries have received little attention as an element in ‘muscle strain’. In thigh muscles, such as rectus femoris and biceps femoris, the attached tendon extends for a significant distance within the muscle belly. While the pathology of most muscle injures occurs at a musculotendinous junction, at first glance the athlete appears to report pain within a muscle belly. In addition to the musculotendinous injury being a site of pathology, the intramuscular tendon itself is occasionally injured. These injuries have a variety of appearances on MRIs. There is some evidence that these injuries require a prolonged rehabilitation time and may have higher recurrence rates. Therefore, it is important to recognise the tendon component of a thigh ‘muscle strain’. PMID:26519522

  10. Ultrasound-guided femoral nerve block as a diagnostic aid in demonstrating quadriceps involvement in bovine spastic paresis.

    PubMed

    De Vlamynck, Caroline; Vlaminck, Lieven; Hauspie, Stijn; Saunders, Jimmy; Gasthuys, Frank

    2013-06-01

    The aim of this study was to evaluate the clinical effects of a femoral nerve block via a dorsal paralumbar injection in healthy calves and calves suffering from spastic paresis. Based on bony landmarks and using ultrasound guidance, the femoral nerves of eight healthy calves were blocked bilaterally with a 4% procaine solution containing blue dye. In 11/16 nerve blocks, paralysis of the quadriceps muscle was obtained after dorsal paralumbar injection. Paralysis was total in 8/16 cases. The injection site was confirmed by post mortem dissection, and in 12/16 cases, the blue dye was found <2mm from the nerve. Clinical use of the technique was then demonstrated in two cases of atypical bovine spastic paresis. In such calves an objective diagnostic tool is required to identify those calves which are suitable for partial tibial neurectomy. The femoral nerve block used in this study has the potential to be such a method and can be used to establish the involvement of the quadriceps femoris in calves suffering from the quadriceps or mixed presentation form of spastic paresis. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Delayed presentation of compartment syndrome of the thigh secondary to quadriceps trauma and vascular injury in a soccer athlete.

    PubMed

    How, Moo Ing; Lee, Puah Ken; Wei, Tan See; Chong, Chua Tai

    2015-01-01

    Compartment syndrome isolated to the anterior thigh is a rare complication of soccer injury. Previous reports in the English literature on sports trauma-related compartment syndrome of the thigh are vague in their description of the response of thigh musculature to blunt trauma, magnetic resonance imaging (MRI) findings of high-risk features of compartment syndrome, vascular injury in quadriceps trauma, and the role of vascular study in blunt thigh injury. We present herein the rare case of a 30-year-old man who developed thigh compartment syndrome 8 days after soccer injury due to severe edema of vastus intermedius and large thigh hematoma secondary to rupture of the profunda femoris vein. MRI revealed "blow-out" rupture of the vastus lateralis. Decompressive fasciotomy and vein repair performed with subsequent split-skin grafting of the wound defect resulted in a good functional outcome at 2-years follow-up. A high index of suspicion for compartment syndrome is needed in all severe quadriceps contusion. Vascular injury can cause thigh compartment syndrome in sports trauma. MRI findings of deep thigh muscle swelling and "blow-out" tear of the vastus lateralis are strongly suggestive of severe quadriceps injury, and may be a harbinger of delayed thigh compartment syndrome. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Myoeletric Activity of the Quadriceps During Leg Press Exercise Performed With Differing Techniques.

    PubMed

    Machado, Wallace; Paz, Gabriel; Mendes, Leonardo; Maia, Marianna; Winchester, Jason B; Lima, Vicente; Willardson, Jeffrey M; Miranda, Humberto

    2017-02-01

    Machado, W, Paz, G, Mendes, L, Maia, M, Winchester, JB, Lima, V, Willardson, JM, and Miranda, H. Myoeletric activity of the quadriceps during leg press exercise performed with differing techniques. J Strength Cond Res 31(2): 422-429, 2017-The quadriceps muscle supplies the motive force for dynamic knee extension. During this action, the vastus medialis oblique (VMO) and vastus lateralis (VL) co-contract to stabilize the patella as it tracks within the patellofemoral groove. The purpose of this study was to analyze surface electromyographic (SEMG) responses for the VL, VMO, rectus femoris (RF), and biceps femoris (BF), as well as the VMO:VL ratio during an open-kinetic chain 45° angled leg press (LP45). The traditional LP45 technique was compared with 2 alternative LP45 exercise techniques that used a physioball and elastic band, respectively. Thirteen female college students performed 3 protocols in random order: TRAD-1 LP45 set performed using the traditional exercise technique, PBALL-1 LP45 set performed with a physioball held between the knee joints, and PEB-1 LP45 set performed with an elastic band proximal to the knee joints. Ten repetitions at 70% of a 10 repetition maximum load were performed in each protocol, and the SEMG data were recorded for the VMO, VL, RF, and BF muscles. Significant increases in VMO activity were noted during PBALL vs. PEB (p = 0.001) and TRAD (p = 0.002). Higher VMO activity was noted during TRAD vs. PEB (p = 0.001). Greater VL activity was noted during PBALL vs. TRAD (p = 0.0001) and PEB (p = 0.0001). The PBALL condition elicited a greater VMO:VL ratio during the concentric phase vs. the PEB (p = 0.001) and TRAD (p = 0.001) protocols. Greater RF activity was observed during PEB vs. TRAD (p = 0.001) and PBALL (p = 0.001). Therefore, practitioners should consider placing a physioball between the knees during the LP45 exercise as an alternative technique when greater overall quadriceps activity is desired for clinical rehabilitation

  13. Quadriceps Muscle Mechanical Simulator for Training of Vastus Medialis Obliquus and Vastus Lateralis Obliquus Mechanical Properties

    PubMed Central

    Irmak, Rafet; Irmak, Ahsen; Biçer, Gökhan

    2014-01-01

    Objectives: In classical anatomy quadriceps muscle has four heads. Clinical studies have demostrated 6 heads of this muscle. These heads were demostrated seperately not only by their functional properties,but also by innervation and kinesiological properties. In our previous study we have developed and demostrated electrophysiological properties of vastus medialis obliquus by an electronic patient simulator. The purpose of this study is to develop a mechanical simulator which can be used to demostrate mechanical properties of 6 heads of quadriceps muscle and the screw home mechanism. Methods: Quadriceps femoris muscle has 6 heads: rectus femoris, vastus intermedius, vastus medialis obliquus, vastus medialis longus, vastus lateralis obliquus and vastus lateralis longus. The fundamental mechanical properties of each head is seperated by insersio and angle of pull. Main design principle was to demostrate all heads with insersio and angle of pull properties. Second design principle was to demostrate the screw-home mechanism which is the result of difference in articular surfaces of medial and lateral of condyles of femur. Results: Final design of the simulator consists of three planes for demostration of angle of pull and pulling forces (patellar plane, proximal and distal planes) of each heads. On each plane channels were graved as origo and insersio for demostration of angle of pull. Distal plane was movable for demostration of pulling forces in different angels of knee flexion and extention. Also proximal plane was adjustable to demostrate different sitting and standing positions. Srew home mechanism was demostrated by specially designed hingle mechanism. Left and right side hingle mechanisms have different radii as femoral condyles and this difference can cause rotation in terminal extension as in the screw home mechanism. Conclusion: Vastus medialis obliquus, vastus lateralis obliquus and screw-home mechanism have clinical significance. We were not able to find

  14. Muscle deoxygenation in the quadriceps during ramp incremental cycling: Deep vs. superficial heterogeneity.

    PubMed

    Okushima, Dai; Poole, David C; Rossiter, Harry B; Barstow, Thomas J; Kondo, Narihiko; Ohmae, Etsuko; Koga, Shunsaku

    2015-12-01

    Muscle deoxygenation (i.e., deoxy[Hb + Mb]) during exercise assesses the matching of oxygen delivery (Q̇O2) to oxygen utilization (V̇O2). Until now limitations in near-infrared spectroscopy (NIRS) technology did not permit discrimination of deoxy[Hb + Mb] between superficial and deep muscles. In humans, the deep quadriceps is more highly vascularized and oxidative than the superficial quadriceps. Using high-power time-resolved NIRS, we tested the hypothesis that deoxygenation of the deep quadriceps would be less than in superficial muscle during incremental cycling exercise in eight males. Pulmonary V̇O2 was measured and muscle deoxy[Hb + Mb] was determined in the superficial vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF-s) and the deep rectus femoris (RF-d). deoxy[Hb + Mb] in RF-d was significantly less than VL at 70% (67.2 ± 7.0 vs. 75.5 ± 10.7 μM) and 80% (71.4 ± 11.0 vs. 79.0 ± 15.4 μM) of peak work rate (WR(peak)), but greater than VL and VM at WR(peak) (87.7 ± 32.5 vs. 76.6 ± 17.5 and 75.1 ± 19.9 μM). RF-s was intermediate at WR(peak) (82.6 ± 18.7 μM). Total hemoglobin and myoglobin concentration and tissue oxygen saturation were significantly greater in RF-d than RF-s throughout exercise. The slope of deoxy[Hb + Mb] increase (proportional to Q̇O2/V̇O2) in VL and VM slowed markedly above 70% WR(peak), whereas it became greater in RF-d. This divergent deoxygenation pattern may be due to a greater population of slow-twitch muscle fibers in the RF-d muscle and the differential recruitment profiles and vascular and metabolic control properties of specific fiber populations within superficial and deeper muscle regions.

  15. Isokinetic Hamstrings: Quadriceps Ratios in Intercollegiate Athletes.

    ERIC Educational Resources Information Center

    Rosene, John M.; Fogarty, Tracey D.; Mahaffey, Brian L.

    2001-01-01

    Compared the differences in the concentric hamstrings to quadriceps (H:Q) ratio among athletes in different sports at three velocities. Measurement of H:Q ratio of both knees among male and female college athletes indicated that the H:Q ratio increased as velocity increased. No differences existed for the H:Q ratio for sport or side of body. (SM)

  16. Isokinetic Hamstrings: Quadriceps Ratios in Intercollegiate Athletes.

    ERIC Educational Resources Information Center

    Rosene, John M.; Fogarty, Tracey D.; Mahaffey, Brian L.

    2001-01-01

    Compared the differences in the concentric hamstrings to quadriceps (H:Q) ratio among athletes in different sports at three velocities. Measurement of H:Q ratio of both knees among male and female college athletes indicated that the H:Q ratio increased as velocity increased. No differences existed for the H:Q ratio for sport or side of body. (SM)

  17. Light microscopic histology of quadriceps tendon ruptures.

    PubMed

    Maffulli, Nicola; Del Buono, Angelo; Spiezia, Filippo; Longo, Umile Giuseppe; Denaro, Vincenzo

    2012-11-01

    To assess histological changes and possible differences in the quadriceps of patients undergoing open repair of the tendon after spontaneous rupture, and subjects with no history of tendon pathology. Biopsies were harvested from the quadriceps tendon of 46 patients (34 men, 12 women) who had reported unilateral atraumatic quadriceps tendon rupture and had undergone surgical repair of the tendon. Samples were also harvested from both the tendons in 11 (N = 11 × 2) patients, nine males and two females, dying from cardiovascular disorders. For each tendon, three slides were randomly selected and examined under light microscopy, and assessed using a semiquantitative grading scale (range 0-21) which considers fibre structure, fibre arrangement, rounding of the nuclei, regional variations in cellularity, increased vascularity, decreased collagen stainability, and hyalinisation. The pathological sum-score averaged 19.2 ± 3.7 in ruptured tendons and 5.6 ± 2.0 in controls, and all variables considered were significantly different between the two groups, showing an association between tendon abnormalities and rupture (0.05 < P < 0.001). This study confirms that the presence of histological degenerative changes in torn quadriceps tendons increases the risk of rupture.

  18. Effects of Wearing a Compression Garment During Night Sleep on Recovery From High-Intensity Eccentric-Concentric Quadriceps Muscle Fatigue.

    PubMed

    Shimokochi, Yohei; Kuwano, Satoshi; Yamaguchi, Taichi; Abutani, Hiroyuki; Shima, Norihiro

    2017-10-01

    Shimokochi, Y, Kuwano, S, Yamaguchi, T, Abutani, H, and Shima, N. Effects of wearing a compression garment during night sleep on recovery from high-intensity eccentric-concentric quadriceps muscle fatigue. J Strength Cond Res 31(10): 2816-2824, 2017-This study aimed to investigate the effects of wearing a compression garment (CG) during night sleep on muscle fatigue recovery after high-intensity eccentric and concentric knee extensor exercises. Seventeen male college students participated in 2 experimental sessions under CG and non-CG (NCG) wearing conditions. Before night sleep under CG or NCG wearing conditions, the subjects performed a fatiguing protocol consisting of 10 sets of 10 repetitions of maximal isokinetic eccentric and concentric knee extensor contractions, with 30-second rest intervals between the sets. Immediately before and after and 24 hours after the fatiguing protocol, maximum voluntary isometric contraction (MVIC) force for knee extensor muscles was measured; surface electromyographic data from the vastus medialis and rectus femoris were also measured. A 2-way repeated-measure analysis of variance followed by Bonferroni pairwise comparisons were used to analyze the differences in each variable. Paired-sample t-tests were used to analyze the mean differences between the conditions at the same time points for each variable. The MVIC 24 hours after the fatiguing protocol was approximately 10% greater in the CG than in the NCG condition (p = 0.033). Changes in the electromyographic variables over time did not significantly differ between the conditions. Thus, it was concluded that wearing a CG during night sleep may promote localized muscle fatigue recovery but does not influence neurological factors after the fatiguing exercise.

  19. In vivo muscle architecture and size of the rectus femoris and vastus lateralis in children and adolescents with cerebral palsy.

    PubMed

    Moreau, Noelle G; Teefey, Sharlene A; Damiano, Diane L

    2009-10-01

    Our aim was to investigate muscle architecture and size of the rectus femoris (RF) and vastus lateralis (VL) in children and adolescents with cerebral palsy (CP) compared with age-matched typically developing participants. Muscle architecture and size were measured with ultrasound imaging in 18 participants with spastic CP (9 females, 9 males; age range 7.5-19 y; mean age 12 y [SD 3 y 2 mo]) within Gross Motor Function Classification System levels I (n=4), II (n=2), III (n=9), and IV (n=3) and 12 typically developing participants (10 females, 2 males; age range 7-20 y; mean age 12 y 4 mo [SD 3 y 11 mo]). Exclusion criteria were orthopedic surgery or neurosurgery within 6 months before testing or botulinum toxin injections to the quadriceps within 3 months before testing. RF cross-sectional area was significantly lower (48%), RF and VL muscle thickness 30% lower, RF fascicle length 27% lower, and VL fascicle angle 3 degrees less in participants with CP compared to the typically developing participants (p<0.05). Intraclass correlation coefficients were >or=0.93 (CP) and >or= 0.88 (typical development), indicating excellent reliability. These results provide the first evidence of altered muscle architecture and size of the RF and VL in CP, similar to patterns observed with disuse and aging. These alterations may play a significant role in the decreased capacity for force generation as well as decreased shortening velocity and range of motion over which the quadriceps can act.

  20. Acute Calcific Tendinitis of the Rectus Femoris: A Case Series

    PubMed Central

    Kobayashi, Hideo; Kaneko, Haruka; Homma, Yasuhiro; Baba, Tomonori; Kaneko, Kazuo

    2015-01-01

    Introduction: Periarticular calcific tendinitis is a common cause of Orthopedic outpatient referral. Calcific tendinitis of the rectus femoris, however, is very rare and not well known. Due to its rarity, correct diagnosis and prompt treatment are not fully understood. Case Report: Two females (38 and 40 years old) of acute calcific tendinitis of the rectus femoris with the good clinical course without any operative treatment were presented. The pain was managed with oral non-steroidal antiinflammatory drugs and/or local steroid injection. Interval radiographic assessment showed complete resorption of the calcification. Conclusion: Establishing the correct diagnosis and initiating prompt treatment are shown to be important in achieving resolution of symptoms and in avoiding unnecessary investigations. PMID:27299063

  1. Endovascular Repair of a Large Profunda Femoris Artery Pseudoaneurysm

    PubMed Central

    Khalid, Ahsan Syed; Ghanem, Omar M.; Mojtaba Gashti, Seyed

    2014-01-01

    Profunda femoris artery aneurysms and pseudoaneurysms are a rare cause of peripheral arterial aneurysms but their risk of rupture is quite high. We have presented a case of a left lower leg pseudoaneurysm. We have shown that endovascular repair with angioplasty and stenting is a suitable treatment method for such a pseudoaneurysm. Due to the limited data on this disease, we suggest multi-institute collaboration to identify and standardize management for the treatment. PMID:24716098

  2. Heterogeneous recruitment of quadriceps muscle portions and fibre types during moderate intensity knee-extensor exercise: effect of thigh occlusion.

    PubMed

    Krustrup, P; Söderlund, K; Relu, M U; Ferguson, R A; Bangsbo, J

    2009-08-01

    The involvement of quadriceps femoris muscle portions and fibre type recruitment was studied during submaximal knee-extensor exercise without and with thigh occlusion (OCC) and compared with responses during intense exercise. Six healthy male subjects performed 90-s of moderate exercise without (MOD; 29+/-4 W) and with thigh OCC, and moderate exercise followed by 90-s of intense exercise (HI; 65+/-8 W). Temperatures were continuously measured in m. vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) and successive muscle biopsies were obtained from VL. During MOD, muscle temperature increase (DeltaT(m)) in RF was 0.52+/-0.09 degrees C, which was 57% and 73% higher (P<0.05) than in VL and VM, respectively. During OCC, DeltaT(m) in RF was 0.39+/-0.05 degrees C, which was not different from VM but 54% higher (P<0.05) than in VL. After MOD, muscle CP in slow twitch (ST) and fast twitch (FT) fibres was 81% and 91% of resting levels, respectively, with lower (P<0.05) values after OCC (15% and 22%) and HI (24% and 13%). After MOD, OCC and HI, a total of 48%, 93% and 96% of the ST fibres had CP levels below mean-1 SD, respectively, with corresponding values for FT fibres being 41%, 89% and 100%, respectively. In conclusion, a heterogeneous recruitment of the quadriceps muscle portions and muscle fibres was observed during submaximal knee-extensor exercise, whereas recruitment pattern was homogenous during intense exercise. Thigh OCC caused an altered recruitment of fibres and muscle portions, suggesting a significant afferent response affecting the activation of fibres in the contracting muscles.

  3. Changes in voluntary quadriceps activation predict changes in quadriceps strength after therapeutic exercise in patients with knee osteoarthritis.

    PubMed

    Pietrosimone, Brian G; Saliba, Susan A

    2012-12-01

    Recent rehabilitation paradigms have suggested that improving voluntary muscle activation may optimize strength outcomes related to resistance training. The aim of this study was to determine if changes in voluntary quadriceps activation could predict changes in quadriceps strength following a 4 week therapeutic exercise regimen. Thirty-six participants with tibiofemoral osteoarthritis volunteered for this study, while 30 participants (14 males, 16 females, 58 ± 11.8 years, 172.2 ± 9.2 cm, 87.1 ± 18.5 kg) finished the 4 week supervised therapeutic exercise protocol and were used in the final analysis. Demographics, quadriceps strength and voluntary quadriceps activation using the burst superimposition technique were evaluated prior to the intervention. Following the therapeutic exercise program, quadriceps strength and voluntary activation were assessed. Simple correlations were performed to determine covariates in a multiple regression equation to evaluate if changes in voluntary quadriceps activation could predict changes in quadriceps strength. There was a significant moderate simple correlation between participant height and change in MVIC (r=-0.44, P=0.01). Both height and changes in voluntary quadriceps activation significantly predicted changes in MVIC (R(2)=0.66, P<0.001). After controlling for patient height, a change in voluntary quadriceps activation produced a significant improvement in the prediction of a change in MVIC (ΔR(2)=0.47, P<0.001). Changes in voluntary quadriceps activation predicted 47% of variance in the change in quadriceps strength. These results suggest that interventions aimed at manipulating quadriceps activation may be helpful for improving quadriceps strength in patients with tibiofemoral osteoarthritis. Copyright © 2012. Published by Elsevier B.V.

  4. 'Serious thigh muscle strains': beware the intramuscular tendon which plays an important role in difficult hamstring and quadriceps muscle strains.

    PubMed

    Brukner, Peter; Connell, David

    2016-02-01

    Why do some hamstring and quadriceps strains take much longer to repair than others? Which injuries are more prone to recurrence? Intramuscular tendon injuries have received little attention as an element in 'muscle strain'. In thigh muscles, such as rectus femoris and biceps femoris, the attached tendon extends for a significant distance within the muscle belly. While the pathology of most muscle injures occurs at a musculotendinous junction, at first glance the athlete appears to report pain within a muscle belly. In addition to the musculotendinous injury being a site of pathology, the intramuscular tendon itself is occasionally injured. These injuries have a variety of appearances on MRIs. There is some evidence that these injuries require a prolonged rehabilitation time and may have higher recurrence rates. Therefore, it is important to recognise the tendon component of a thigh 'muscle strain'. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  5. Activity in three parts of the quadriceps recorded isometrically at two different knee angles and during a functional exercise.

    PubMed

    Morrish, G M; Woledge, R C; Haddad, F S

    2003-01-01

    The purpose of this study was to evaluate individual differences in three parts of the quadriceps activated isometrically at 60 degrees and 90 degrees of knee flexion, and during a functional activity involving both concentric and eccentric muscle work. Surface EMG amplitudes were therefore recorded from oblique parts of vastus medialis (VMO) and vastus lateralis (VLO) and from rectus femoris (RF). VMO and VLO showed less activation at 60 degrees than at 90 degrees, but in RF there was no difference between the two angles. In the second experiment, where 11 subjects stepped on and off a stool; these amplitudes were compared with those from a maximal isometric voluntary contraction at 90 degrees of knee flexion. For VMO & VLO the normalised peak amplitude in stepping up was 1.41 +/- 0.12, & 1.46 +/- 0.15 respectively, showing that higher activity is necessary during concentric contractions. These two results suggest that the motor control of VMO/VLO may be different from the bulk of quadriceps. Our findings have implications for patellofemoral function.

  6. High-Velocity Quadriceps Exercises Compared to Slow-Velocity Quadriceps Exercises Following Total Knee Arthroplasty: A Randomized Clinical Study.

    PubMed

    Doerfler, Deborah; Gurney, Burke; Mermier, Christine; Rauh, Mitchell; Black, Liza; Andrews, Ron

    2016-01-01

    Despite improvement in pain and perceived function in older adults following total knee arthroplasty (TKA), objective outcome measures of muscular impairment and ambulatory function demonstrate significant deficits. Evidence suggests that quadriceps power may play a greater role in ambulatory function than measures of strength alone following TKA. The purpose of this study was to compare the effect of high-velocity (HV) quadriceps exercises with that of slow-velocity (SV) quadriceps exercises on functional outcomes and quadriceps power following TKA. This study was a randomized clinical study conducted in an outpatient physical therapy clinic. Twenty-one participants who were 4 to 6 weeks post unilateral TKA were randomly assigned to an HV or SV group. Participants performed an evidence-based standardized progressive resistance exercise program in addition to HV quadriceps exercises or SV quadriceps exercises. Participants attended 2 sessions per week for 8 weeks. Before and after the 8-week exercise intervention, participants completed a functional questionnaire, health survey, functional testing, and underwent quadriceps strength and power testing. Both groups demonstrated improvements in ambulatory outcome measures, strength, speed, and power. The HV group demonstrated significantly greater improvements in distance walked and quadriceps strength than the SV group. These data should be considered preliminary because of a small sample size. HV quadriceps exercises may be an effective rehabilitation strategy in conjunction with a standardized progressive resistance exercise program beginning 4 to 6 weeks after TKA.

  7. Dry needling: Effects on activation and passive mechanical properties of the quadriceps, pain and range during late stage rehabilitation of ACL reconstructed patients.

    PubMed

    Ortega-Cebrian, Silvia; Luchini, Nicolleta; Whiteley, Rodney

    2016-09-01

    Dry needling (DN) is reported to decrease pain and improve functional movements yet the mechanisms remain unclear. Changes in muscle tone and other mechanical properties after DN could contribute to these findings but have not been investigated. Examine EMG and passive mechanical properties of the quadriceps muscle before and after DN. EMG, MyotonPro and clinical measurements were taken pre and post DN. Rehabilitation department at Aspetar Sports Medicine Hospital, Qatar. 20 subjects reporting pain and quadriceps muscle tension. Pain (VAS, measured during a single leg step down), knee flexion range, and passive mechanical properties of the superficial quadriceps were measured using the MyotonPro device. Pain decreased (p < 0.01) and ROM increased in flexion (p < 0.001). EMG activity (RMS) was decreased at rest in the Vastus Lateralis (VL (p < 0.05, ES = 0.22). All other sEMG parameters were not significantly different (all p > 0.11, ES = 0.13). Passive mechanical properties were not significantly different in rectus femoris (RF) and VL. Decrement and Resistance of the Vastus Medialis (VM) were significantly decreased (p<0.05, ES>0.19). DN resulted in small reductions in: pain, resting activation (EMG of VL), decrement and resistance (of VM). Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Transcranial Magnetic Stimulation and Volitional Quadriceps Activation

    PubMed Central

    Gibbons, Christopher E.; Pietrosimone, Brian G.; Hart, Joseph M.; Saliba, Susan A.; Ingersoll, Christopher D.

    2010-01-01

    Abstract Context: Quadriceps-activation deficits have been reported after meniscectomy. Transcranial magnetic stimulation (TMS) in conjunction with maximal contractions affects quadriceps activation in patients after meniscectomy. Objective: To determine the effect of single-pulsed TMS on quadriceps central activation ratio (CAR) in patients after meniscectomy. Design: Randomized controlled clinical trial. Setting: University laboratory. Patients or Other Participants: Twenty participants who had partial meniscectomy and who had a CAR less than 85% were assigned randomly to the TMS group (7 men, 4 women; age  =  38.1 ± 16.2 years, height  =  176.8 ± 11.5 cm, mass  =  91.8 ± 27.5 kg, postoperative time  =  36.7 ± 34.9 weeks) or the control group (7 men, 2 women; age  =  38.2 ± 17.5 years, height  =  176.5 ± 7.9 cm, mass  =  86.2 ± 15.3 kg, postoperative time  =  36.6 ± 37.4 weeks). Intervention(s): Participants in the experimental group received TMS over the motor cortex that was contralateral to the involved leg and performed 3 maximal quadriceps contractions with the involved leg. The control group performed 3 maximal quadriceps contractions without the TMS. Main Outcome Measure(s): Quadriceps activation was assessed using the CAR, which was measured in 70° of knee flexion at baseline and at 0, 10, 30, and 60 minutes posttest. The CAR was expressed as a percentage of full activation. Results: Differences in CAR were detected over time (F4,72  =  3.025, P  = .02). No interaction (F4,72  =  1.457, P  =  .22) or between-groups differences (F1,18  =  0.096, P  =  .76) were found for CAR. Moderate CAR effect sizes were found at 10 (Cohen d  =  0.54, 95% confidence interval [CI]  =  −0.33, 1.37) and 60 (Cohen d  =  0.50, 95% CI  =  −0.37, 1.33) minutes in the TMS group compared with CAR at baseline. Strong effect sizes were found for CAR at 10 (Cohen d  =  0.82, 95% CI

  9. Neuromuscular function of the quadriceps muscle during isometric maximal, submaximal and submaximal fatiguing voluntary contractions in knee osteoarthrosis patients

    PubMed Central

    Jacksteit, Robert; Jackszis, Mario; Feldhege, Frank; Weippert, Matthias; Mittelmeier, Wolfram; Bader, Rainer; Skripitz, Ralf; Behrens, Martin

    2017-01-01

    Introduction Knee osteoarthrosis (KOA) is commonly associated with a dysfunction of the quadriceps muscle which contributes to alterations in motor performance. The underlying neuromuscular mechanisms of muscle dysfunction are not fully understood. The main objective of this study was to analyze how KOA affects neuromuscular function of the quadriceps muscle during different contraction intensities. Materials and methods The following parameters were assessed in 20 patients and 20 healthy controls: (i) joint position sense, i.e. position control (mean absolute error, MAE) at 30° and 50° of knee flexion, (ii) simple reaction time task performance, (iii) isometric maximal voluntary torque (IMVT) and root mean square of the EMG signal (RMS-EMG), (iv) torque control, i.e. accuracy (MAE), absolute fluctuation (standard deviation, SD), relative fluctuation (coefficient of variation, CV) and periodicity (mean frequency, MNF) of the torque signal at 20%, 40% and 60% IMVT, (v) EMG-torque relationship at 20%, 40% and 60% IMVT and (vi) performance fatigability, i.e. time to task failure (TTF) at 40% IMVT. Results Compared to the control group, the KOA group displayed: (i) significantly higher MAE of the angle signal at 30° (99.3%; P = 0.027) and 50° (147.9%; P < 0.001), (ii) no significant differences in reaction time, (iii) significantly lower IMVT (-41.6%; P = 0.001) and tendentially lower RMS-EMG of the rectus femoris (-33.7%; P = 0.054), (iv) tendentially higher MAE of the torque signal at 20% IMVT (65.9%; P = 0.068), significantly lower SD of the torque signal at all three torque levels and greater MNF at 60% IMVT (44.8%; P = 0.018), (v) significantly increased RMS-EMG of the vastus lateralis at 20% (70.8%; P = 0.003) and 40% IMVT (33.3%; P = 0.034), significantly lower RMS-EMG of the biceps femoris at 20% (-63.6%; P = 0.044) and 40% IMVT (-41.3%; P = 0.028) and tendentially lower at 60% IMVT (-24.3%; P = 0.075) and (vi) significantly shorter TTF (-51.1%; P = 0

  10. Variations in medial-lateral hamstring force and force ratio influence tibiofemoral kinematics.

    PubMed

    Shalhoub, Sami; Fitzwater, Fallon G; Cyr, Adam J; Maletsky, Lorin P

    2016-10-01

    A change in hamstring strength and activation is typically seen after injuries or invasive surgeries such as anterior cruciate reconstruction or total knee replacement. While many studies have investigated the influence of isometric increases in hamstring load on knee joint kinematics, few have quantified the change in kinematics due to a variation in medial to lateral hamstring force ratio. This study examined the changes in knee joint kinematics on eight cadaveric knees during an open-chain deep knee bend for six different loading configurations: five loaded hamstring configurations that varied the ratio of a total load of 175 N between the semimembranosus and biceps femoris and one with no loads on the hamstring. The anterior-posterior translation of the medial and lateral femoral condyles' lowest points along proximal-distal axis of the tibia, the axial rotation of the tibia, and the quadriceps load were measured at each flexion angle. Unloading the hamstring shifted the medial and lateral lowest points posteriorly and increased tibial internal rotation. The influence of unloading hamstrings on quadriceps load was small in early flexion and increased with knee flexion. The loading configuration with the highest lateral hamstrings force resulted in the most posterior translation of the medial lowest point, most anterior translation of the lateral lowest point, and the highest tibial external rotation of the five loading configurations. As the medial hamstring force ratio increased, the medial lowest point shifted anteriorly, the lateral lowest point shifted posteriorly, and the tibia rotated more internally. The results of this study, demonstrate that variation in medial-lateral hamstrings force and force ratio influence tibiofemoral transverse kinematics and quadriceps loads required to extend the knee. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1707-1715, 2016. © 2016 Orthopaedic Research Society. Published by

  11. Differences in twitch potentiation between voluntary and stimulated quadriceps contractions of equal intensity.

    PubMed

    Jubeau, M; Gondin, J; Martin, A; Van Hoecke, J; Maffiuletti, N A

    2010-02-01

    This study compared the extent of twitch and M-wave potentiation (POT) between voluntary and stimulated quadriceps contractions performed at the same intensity. Sixteen healthy men completed 10-s isometric knee extensions at 40% of the maximal voluntary contraction torque under electrical stimulation and voluntary conditions. Single stimuli were delivered to the femoral nerve to evoke twitches before (PRE) and from 3 to 600 s after the end of each conditioning contraction. Changes in twitch contractile properties and M-wave characteristics were compared between the conditions. The extent of twitch peak torque POT was smaller for the stimulated (122+/-20% of PRE) than for the voluntary condition (133+/-20% of PRE). The magnitude of POT for the maximal rate of twitch torque development was also smaller for the stimulated trial. Rectus femoris M-wave amplitude was potentiated by the voluntary but not by the stimulated contraction. It was concluded that stimulated contractions resulted in smaller twitch and M-wave POT than voluntary contractions, despite equivalent torque output and duration. The spatially and temporally fixed recruitment of motor units with electrical stimulation and therefore the lower number of activated motor units compared with voluntary actions of equal intensity could explain the present findings.

  12. Longer electromechanical delay impairs hamstrings explosive force versus quadriceps.

    PubMed

    Hannah, Ricci; Minshull, Claire; Smith, Stephanie L; Folland, Jonathan P

    2014-01-01

    Explosive neuromuscular performance refers to the ability to rapidly increase force in response to neuromuscular activation. The lower explosive force production of the hamstrings relative to the quadriceps could compromise knee joint stability and increase the risk of anterior cruciate ligament injury. However, the time course of the rise in explosive force of the hamstrings and quadriceps from their initial activation, and thus the explosive hamstrings-to-quadriceps (H/Q) force ratio, has not been documented. The neuromuscular performance of 20 untrained males was assessed during a series of isometric knee flexion and extension contractions, with force and surface EMG of the hamstrings and quadriceps recorded during explosive and maximum voluntary contractions. Hamstrings force was expressed relative to quadriceps force to produce hamstring-to-quadriceps ratios of explosive H/Q force and H/Q maximum voluntary force. For the explosive contractions, agonist electromechanical delay (EMD), agonist and antagonist neural activation were assessed. The quadriceps was 79% stronger than the hamstrings, but quadriceps explosive force was up to 480% greater than the hamstrings from 25 to 50 ms after first activation. Consequently, the explosive H/Q force ratio was very low at 25 and 50 ms (0%-17%) and significantly different from H/Q maximum voluntary force ratio (56%). Hamstrings EMD was 95% greater than quadriceps EMD (44.0 vs 22.6 ms), resulting in a 21-ms later onset of force in the hamstrings that appeared to explain the low explosive H/Q force ratio in the early phase of activation. Prolonged hamstrings EMD appears to impair early phase (0-50 ms) explosive force production relative to the quadriceps and may render the knee unstable and prone to anterior cruciate ligament injury during this period.

  13. Dynamic in vivo quadriceps lines-of-action.

    PubMed

    Wilson, Nicole A; Sheehan, Frances T

    2010-08-10

    Tissue stresses and quadriceps forces are crucial factors when considering knee joint biomechanics. However, it is difficult to obtain direct, in vivo, measurements of these quantities. The primary purpose of this study was to provide the first complete description of quadriceps geometry (force directions and moment arms) of individual quadriceps components using in vivo, 3D data collected during volitional knee extension. A secondary purpose was to determine if 3D quadriceps geometry is altered in patients with patellofemoral pain and maltracking. After obtaining informed consent, cine-phase contrast (PC) MRI sets (x,y,z velocity and anatomic images) were acquired from 25 asymptomatic knees and 15 knees with patellofemoral pain during active knee extension. Using a sagittal-oblique and two coronal-oblique imaging planes, the origins and insertions of each quadriceps line-of-action were identified and tracked throughout the motion by integrating the cine-PC velocity data. The force direction and relative moment (RM) were calculated for each line-of-action. All quadriceps lines-of-action were oriented primarily in the superior direction. There were no significant differences in quadriceps geometry between asymptomatic and subjects with patellofemoral pain. However, patellofemoral kinematics were significantly different between the two populations. This study will improve the ability of musculoskeletal models to closely match in vivo human performance by providing accurate 3D quadriceps geometry and associated patellofemoral kinematics during dynamic knee motion. Furthermore, determination that quadriceps geometry is not altered in patellofemoral pain supports the use of generalized a knee model based on asymptomatic quadriceps architecture.

  14. Static stretching vs. dynamic warm-ups: a comparison of their effects on torque and electromyography output of the quadriceps and hamstring muscles.

    PubMed

    Williams, N; Coburn, J; Gillum, T

    2015-11-01

    The aim of this paper was to determine if two different warm-up protocols differently affect torque of the quadriceps and hamstrings, and electromyography (EMG) output of the rectus femoris (RF) and vastus lateralis (VL) when completing 30 maximal leg extensions and curls. Twenty-one healthy male (N.=8) and female (N.=13) subjects volunteered to participate in a familiarization session and three testing sessions. The three testing sessions control, dynamic, and static were completed in a counterbalanced order on non-consecutive days. First, subjects warmed-up on a treadmill for five minutes before completing six dynamic movements, six static-stretches, or no stretches. They then rested for five minutes before completing 30 maximal leg extensions and curls at a speed of 60 s-1. A significant decrease in quadriceps torque output over time was determined for the dynamic protocol when compared to the control (P<0.01) and static (P<0.05) protocols. A significant decrease was found in peak quadriceps torque for the dynamic protocol (P<0.01) when compared to the static, and a significant increase was found for the static protocol (P<0.05) when compared to the control. A significant decrease in average quadriceps torque was found for the dynamic protocol when compared to the static (P<0.05) and control (P<0.01) protocols. No difference was found in hamstring torque or EMG output of the RF and VL. Short duration static-stretching has the ability to increase peak and average torque of the leg extensors, while some types of anaerobic exercise involving maximal contractions to fatigue may be hindered by performing dynamic movements as part of the warm-up.

  15. Profunda Femoris Pseudoaneurysm following Total Hip Arthroplasty Revision

    PubMed Central

    Harper, Katharine; Iorio, Justin; Balasubramanian, Easwaran

    2015-01-01

    Vascular injuries following total hip arthroplasty (THA) are very rare, with pseudoaneurysm being a small subset. We report a case of profunda femoris artery (PFA) pseudoaneurysm in a 61-year-old male following a posterior approach revision left THA. Presentation involved continued blood transfusion requirements several weeks postoperatively. Diagnosis of the pseduoaneurysm was made by contrast CT of the lower extremity, with confirmation via IR angiography. Successful embolization was achieved with selective coiling and Gelfoam. Presenting complaints of such complications are often vague and therefore lead to delayed diagnosis. Causes of such complications are not completely understood, particularly with PFA injuries in THA. Possible mechanisms are discussed in this paper. Vascular complications following THA can be difficult to diagnose. High suspicion in the setting of continued postoperative pain or bleeding may allow prompt diagnosis and avoidance of serious limb-threatening complications. PMID:26347839

  16. Abdominal muscle and quadriceps strength in chronic obstructive pulmonary disease

    PubMed Central

    Man, W; Hopkinson, N; Harraf, F; Nikoletou, D; Polkey, M; Moxham, J

    2005-01-01

    Background: Quadriceps muscle weakness is common in chronic obstructive pulmonary disease (COPD) but is not observed in a small hand muscle (adductor pollicis). Although this could be explained by reduced activity in the quadriceps, the observation could also be explained by anatomical location of the muscle or fibre type composition. However, the abdominal muscles are of a similar anatomical and fibre type distribution to the quadriceps, although they remain active in COPD. Cough gastric pressure is a recently described technique that assesses abdominal muscle (and hence expiratory muscle) strength more accurately than traditional techniques. A study was undertaken to test the hypothesis that more severe weakness exists in the quadriceps than in the abdominal muscles of patients with COPD compared with healthy elderly controls. Methods: Maximum cough gastric pressure and quadriceps isometric strength were measured in 43 patients with stable COPD and 25 healthy elderly volunteers matched for anthropometric variables. Results: Despite a significant reduction in mean quadriceps strength (29.9 kg v 41.2 kg; 95% CI –17.9 to –4.6; p = 0.001), cough gastric pressure was preserved in patients with COPD (227.3 cm H2O v 204.8 cm H2O; 95% CI –5.4 to 50.6; p = 0.11). Conclusions: Abdominal muscle strength is preserved in stable COPD outpatients in the presence of quadriceps weakness. This suggests that anatomical location and fibre type cannot explain quadriceps weakness in COPD. By inference, we conclude that disuse and consequent deconditioning are important factors in the development of quadriceps muscle weakness in COPD patients, or that activity protects the abdominal muscles from possible systemic myopathic processes. PMID:15923239

  17. Quadriceps force after TKA with femoral single radius.

    PubMed

    Ostermeier, Sven; Stukenborg-Colsman, Christina

    2011-06-01

    New implant designs have incorporated a single radius instead of a multiple radius to the femoral component in order to improve the mechanical function after TKA. We investigated the amount of quadriceps force required to extend the knee during an isokinetic extension cycle of different total knee designs, focusing on the radius of the femoral component (single vs. multiple). Human knee specimens (n = 12, median patient age 68 (63-70) years) were tested in a kinematic knee-simulating machine untreated and after implantation of 2 types of knee prosthesis systems, one with a single femoral radius design and one with a multiple femoral radius design. During the test cycle, a hydraulic cylinder, which simulated the quadriceps muscle, applied sufficient force to the quadriceps tendon to produce a constant extension moment of 31 Nm. The quadriceps extension force was measured from 120° to full knee extension. The shape of the quadriceps force curve was typically sinusoidal before and after TKA, reaching a maximum value of 1,493 N at 110°. With the single femoral radius design, quadriceps force was similar to that of the normal knee: 1,509 N at 110° flexion (p = 0.4). In contrast, the multiple femoral radius design showed an increase in quadriceps extension force relative to the normal knee, with a maximum of 1,721 N at 90° flexion (p = 0.03). The single femoral radius design showed lower maximum extension forces than the multiple femoral radius design. In addition, with the single femoral radius design maximum quadriceps force needed to extend a constant extension force shifted to higher degrees of knee flexion, representing a more physiological quadriceps force pattern, which could have a positive effect on knee function after TKA.

  18. Immediate effect of vibratory stimuli on quadriceps function in healthy adults.

    PubMed

    Pamukoff, Derek N; Pietrosimone, Brian; Lewek, Michael D; Ryan, Eric D; Weinhold, Paul S; Lee, Dustin R; Blackburn, J Troy

    2016-09-01

    The purpose of this study was to compare the effect of whole body vibration (WBV) and local muscle vibration (LMV) on quadriceps function. Sixty adults were randomized to WBV, LMV, or control groups. Quadriceps function [Hoffmann (H)-reflex, active motor threshold (AMT), motor evoked potential (MEP) and electromyographic amplitude, peak torque (PT), rate of torque development (RTD), and central activation ratio (CAR)] was assessed before and immediately after and 10 and 20 minutes after interventions. WBV improved PT, CAR, AMT, EMG, and MEP amplitude, and EMG amplitude and CAR were greater than control after application. LMV improved EMG amplitude and AMT, and EMG amplitude was greater than control after application. AMT remained lower 10 and 20 minutes after WBV and LMV. No differences were noted between LMV and WBV. Vibration did not influence H-reflex or RTD. WBV and LMV increased quadriceps function and may be used to enhance the efficacy of strengthening protocols. Muscle Nerve 54: 469-478, 2016. © 2016 Wiley Periodicals, Inc.

  19. Immediate effects of whole-body vibration on neuromuscular performance of quadriceps and oscillation of the center of pressure: A randomized controlled trial.

    PubMed

    Borges, Daniel T; Macedo, Liane B; Lins, Caio A A; Brasileiro, Jamilson S

    2016-09-01

    Whole body vibration has become a popular practice in training and rehabilitation centers. Although proposed as a useful adjunct to improve various aspects of musculoskeletal function, its real benefits and immediate physiological responses are still uncertain. This study analyzed the immediate effects of whole-body vibration with two distinct frequencies on neuromuscular performance of the quadriceps femoris and in the postural control of healthy subjects. Randomized controlled trial. Sixty physically active women were submitted to an evaluation of the oscillation of the center of pressure through baropodometry and isokinetic performance of quadriceps femoris muscle of the non-dominant limb, associated with the electromyographic amplitude assessment of vastus lateralis muscle. Subjects were randomly divided into three groups: control group - performed an exercise protocol with the vibrating platform off; 30 and 50 Hz groups - conducted the exercise protocol with the platform on, with a frequency of 30 and 50 Hz, respectively. There was a significant reduction in the time of peak torque in three evaluated groups (p < 0.001), with no differences between the groups (p = 0.586). There were no significant differences in pressure center oscillation, peak torque normalized for body weight, total work, and average power nor in the value of the root mean square in any of the groups. This study suggests that the exercise protocol on the vibrating platform does not change neuromuscular performance or the pressure center oscillation of healthy women. CLINICALTRIALS. NCT02416362. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. In vivo patellar tracking induced by individual quadriceps components in individuals with patellofemoral pain

    PubMed Central

    Lin, Fang; Wilson, Nicole A.; Makhsous, Mohsen; Press, Joel M.; Koh, Jason L.; Nuber, Gordon W.; Zhang, Li-Qun

    2009-01-01

    Patellofemoral pain is a common knee disorders with a multi-factorial etiology related to abnormal patellar tracking. Our hypothesis was that the pattern of 3-dimensional rotation and translation of the patella induced by selective activation of individual quadriceps components would differ between subjects with patellofemoral pain and healthy subjects. Nine female subjects with patellofemoral pain and seven healthy female subjects underwent electrical stimulation to selectively activate individual quadriceps components (vastus medialis obliquus, VMO; vastus medialis lateralis, VML; vastus lateralis, VL) with the knee at 0° and 20° flexion, while three-dimensional patellar tracking was recorded. Normalized direction of rotation and direction of translation characterized the relative amplitudes of each component of patellar movement. VMO activation in patellofemoral pain caused greater medial patellar rotation (distal patellar pole rotates medially in frontal plane) at both knee positions (p<0.01), and both VMO and VML activation caused increased anterior patellar translation (p<0.001) in patellofemoral pain compared to healthy subjects at 20° knee flexion. VL activation caused more lateral patellar translation (p<0.001) in patellofemoral pain compared to healthy subjects. In healthy subjects the 3-D mechanical action of the VMO is actively modulated with knee flexion angle while such modulation was not observed in PFP subjects. This could be due to anatomical differences in the VMO insertion on the patella and medial quadriceps weakness. Quantitative evaluation of the influence of individual quadriceps components on patellar tracking will aid understanding of the knee extensor mechanism and provide insight into the etiology of patellofemoral pain. PMID:19878947

  1. In vivo patellar tracking induced by individual quadriceps components in individuals with patellofemoral pain.

    PubMed

    Lin, Fang; Wilson, Nicole A; Makhsous, Mohsen; Press, Joel M; Koh, Jason L; Nuber, Gordon W; Zhang, Li-Qun

    2010-01-19

    Patellofemoral pain is a common knee disorder with a multi-factorial etiology related to abnormal patellar tracking. Our hypothesis was that the pattern of three-dimensional rotation and translation of the patella induced by selective activation of individual quadriceps components would differ between subjects with patellofemoral pain and healthy subjects. Nine female subjects with patellofemoral pain and seven healthy female subjects underwent electrical stimulation to selectively activate individual quadriceps components (vastus medialis obliquus, VMO; vastus medialis lateralis, VML; vastus lateralis, VL) with the knee at 0 degrees and 20 degrees flexion, while three-dimensional patellar tracking was recorded. Normalized direction of rotation and direction of translation characterized the relative amplitudes of each component of patellar movement. VMO activation in patellofemoral pain caused greater medial patellar rotation (distal patellar pole rotates medially in frontal plane) at both knee positions (p<0.01), and both VMO and VML activation caused increased anterior patellar translation (p<0.001) in patellofemoral pain compared to healthy subjects at 20 degrees knee flexion. VL activation caused more lateral patellar translation (p<0.001) in patellofemoral pain compared to healthy subjects. In healthy subjects the 3-D mechanical action of the VMO is actively modulated with knee flexion angle while such modulation was not observed in PFP subjects. This could be due to anatomical differences in the VMO insertion on the patella and medial quadriceps weakness. Quantitative evaluation of the influence of individual quadriceps components on patellar tracking will aid understanding of the knee extensor mechanism and provide insight into the etiology of patellofemoral pain. Copyright 2009 Elsevier Ltd. All rights reserved.

  2. Foraging activity rhythms of Dinoponera quadriceps (Hymenoptera: Formicidae) in its natural environment.

    PubMed

    Medeiros, Jeniffer; Azevedo, Dina L O; Santana, Melquisedec A D; Lopes, Talita R P; Araújo, Arrilton

    2014-01-01

    This study characterizes the foraging activity of the queenless ant Dinoponera quadriceps (Kempf) (Hymenoptera: Formicidae) in its natural environment by testing the hypotheses that foraging activity presents both daily and seasonal rhythmic variations, and that these rhythms are related to environmental variables. Four colonies of D. quadriceps were observed in an area of secondary Atlantic forest in northeastern Brazil. Data collection was performed over 72 h every three months during an annual cycle. Both daily and seasonal foraging activity rhythms of D. quadriceps colonies were related to environmental factors, but colony differences also explained part of foraging variations. Foraging activity of D. quadriceps colonies was predominantly diurnal independently of season. In the early dry season, the colonies had two activity peaks, one in the morning and another in the afternoon, with a decrease in foraging at midday; however, during the rest of the year, foraging activity was distributed more evenly throughout the daylight hours. The daily rhythm of foraging activity was likely determined by an endogenous circadian rhythm year-round, but in the dry season, temperature and relative humidity also influenced daily foraging activity, with a negative effect of temperature and a positive effect of relative humidity. On a seasonal scale, foraging activity peaked in the early dry season and suddenly declined at the end of this season, increasing again at the late rainy season. The seasonal rhythm of foraging was negatively related to relative humidity and positively related to prey availability. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

  3. A dynamic warm-up model increases quadriceps strength and hamstring flexibility.

    PubMed

    Aguilar, Alain J; DiStefano, Lindsay J; Brown, Cathleen N; Herman, Daniel C; Guskiewicz, Kevin M; Padua, Darin A

    2012-04-01

    Research suggests that static stretching can negatively influence muscle strength and power and may result in decreased functional performance. The dynamic warm-up (DWU) is a common alternative to static stretching before physical activity, but there is limited research investigating the effects of a DWU. The purpose of this study was to compare the acute effects of a DWU and static stretching warm-up (SWU) on muscle flexibility, strength, and vertical jump using a randomized controlled trial design. Forty-five volunteers were randomly assigned into a control (CON), SWU, or DWU group. All participants rode a stationary bicycle for 5 minutes and completed a 10-minute warm-up protocol. During this protocol, the DWU group performed dynamic stretching and running, the SWU group performed static stretching, and the CON group rested. Dependent variables were measured immediately before and after the warm-up protocol. A digital inclinometer measured flexibility (degrees) for the hamstrings, quadriceps, and hip flexor muscles. An isokinetic dynamometer measured concentric and eccentric peak torque (N·m/kg) for the hamstrings and quadriceps. A force plate was used to measure vertical jump height (meters) and power (watts). In the DWU group, there was a significant increase in hamstring flexibility (pretest: 26.4 ± 13.5°, posttest: 16.9 ± 9.4°; p < .0001) and eccentric quadriceps peak torque (pretest: 2.49 ± 0.83 N·m/kg, posttest: 2.78 ± 0.69 N·m/kg; p = 0.04). The CON and SWU did not significantly affect any flexibility, strength, or vertical jump measures (p > 0.05). The DWU significantly improved eccentric quadriceps strength and hamstrings flexibility, whereas the SWU did not facilitate any positive or negative changes in muscle flexibility, strength, power, or vertical jump. Therefore, the DWU may be a better preactivity warm-up choice than an SWU.

  4. Roller-Massager Application to the Quadriceps and Knee-Joint Range of Motion and Neuromuscular Efficiency During a Lunge

    PubMed Central

    Bradbury-Squires, David J.; Noftall, Jennifer C.; Sullivan, Kathleen M.; Behm, David G.; Power, Kevin E.; Button, Duane C.

    2015-01-01

    Context: Roller massagers are used as a recovery and rehabilitative tool to initiate muscle relaxation and improve range of motion (ROM) and muscular performance. However, research demonstrating such effects is lacking. Objective: To determine the effects of applying a roller massager for 20 and 60 seconds on knee-joint ROM and dynamic muscular performance. Design: Randomized controlled clinical trial. Setting: University laboratory. Patients or Other Participants: Ten recreationally active men (age = 26.6 ± 5.2 years, height = 175.3 ± 4.3 cm, mass = 84.4 ± 8.8 kg). Intervention(s): Participants performed 3 randomized experimental conditions separated by 24 to 48 hours. In condition 1 (5 repetitions of 20 seconds) and condition 2 (5 repetitions of 60 seconds), they applied a roller massager to the quadriceps muscles. Condition 3 served as a control condition in which participants sat quietly. Main Outcome Measure(s): Visual analog pain scale, electromyography (EMG) of the vastus lateralis (VL) and biceps femoris during roller massage and lunge, and knee-joint ROM. Results: We found no differences in pain between the 20-second and 60-second roller-massager conditions. During 60 seconds of roller massage, pain was 13.5% (5.7 ± 0.70) and 20.6% (6.2 ± 0.70) greater at 40 seconds and 60 seconds, respectively, than at 20 seconds (P < .05). During roller massage, VL and biceps femoris root mean square (RMS) EMG was 8% and 7%, respectively, of RMS EMG recorded during maximal voluntary isometric contraction. Knee-joint ROM was 10% and 16% greater in the 20-second and 60-second roller-massager conditions, respectively, than the control condition (P < .05). Finally, average lunge VL RMS EMG decreased as roller-massage time increased (P < .05). Conclusions: Roller massage was painful and induced muscle activity, but it increased knee-joint ROM and neuromuscular efficiency during a lunge. PMID:25415414

  5. Clinical thresholds for quadriceps assessment after anterior cruciate ligament reconstruction.

    PubMed

    Kuenze, Christopher; Hertel, Jay; Saliba, Susan; Diduch, David R; Weltman, Arthur; Hart, Joseph M

    2015-02-01

    Normal, symmetrical quadriceps strength is a common clinical goal after anterior cruciate ligament reconstruction (ACLR). Currently, the clinical thresholds for acceptable unilateral quadriceps function and symmetry associated with positive outcomes after return to activity are unclear. To establish quadriceps-activation and knee-extension-torque cutoffs for clinical assessment after return to activity after ACLR. Descriptive laboratory study. Laboratory. 22 (10 female, 12 male; age = 22.5 ± 5.0 y, height = 172.9 ± 7.1 cm, mass = 74.1 ± 15.5 kg, months since surgery = 31.5 ± 23.5) recreationally active persons with a history of unilateral, primary ACLR at least 6 months prior and 24 (12 female/12 male, age = 21.7 ± 3.6 y, height = 168.0 ± 8.8 cm, mass = 69.3 ± 13.6 kg) recreationally active healthy participants. Patient-reported measures of pain, knee-related function, and physical activity level were recorded for all participants. Normalized knee-extension maximum-voluntary-isometric-contraction (MVIC) torque (Nm/kg) and quadriceps central-activation ratio (CAR, %) were measured bilaterally in all participants. Receiver-operator-characteristic (ROC) curves were used to establish thresholds for unilateral measures of normalized knee-extension MVIC torque and quadriceps CAR, as well as limb-symmetry indices (LSI). ROC curves then established clinical thresholds for normalized knee-extension MVIC torque and quadriceps CAR LSIs associated with healthy knee-related function. Involved-quadriceps CAR above 89.3% was the strongest unilateral indicator of healthy-group membership, while quadriceps CAR LSI above 0.996 and knee-extension MVIC torque above 0.940 were the strongest overall indicators. Unilateral normalized knee-extension MVIC torque above 3.00 Nm/kg and quadriceps CAR LSI above 0.992 were the best indicators of good patient-reported knee-related outcomes. Threshold values established in this study may provide a guide for clinicians when making return

  6. Anomalous Biceps Femoris Tendon Insertion Leading to a Snapping Knee in a Young Male.

    PubMed

    Fritsch, Brett A; Mhaskar, Vikram

    2017-06-01

    Snapping biceps femoris tendon is an uncommon problem that can be caused by various anatomical aberrations around the knee joint. There are several case reports in the literature describing some of these anatomical variations and their treatment. We present a case of unilateral snapping biceps femoris tendon due to a previously unreported anatomical variation, our technique for successful surgical treatment, and a review of the literature.

  7. Anomalous Biceps Femoris Tendon Insertion Leading to a Snapping Knee in a Young Male

    PubMed Central

    Fritsch, Brett A; Mhaskar, Vikram

    2017-01-01

    Snapping biceps femoris tendon is an uncommon problem that can be caused by various anatomical aberrations around the knee joint. There are several case reports in the literature describing some of these anatomical variations and their treatment. We present a case of unilateral snapping biceps femoris tendon due to a previously unreported anatomical variation, our technique for successful surgical treatment, and a review of the literature. PMID:28545180

  8. Musculo-tendon length and lengthening velocity of rectus femoris in stiff knee gait.

    PubMed

    Jonkers, Ilse; Stewart, Caroline; Desloovere, Kaat; Molenaers, Guy; Spaepen, Arthur

    2006-02-01

    Inappropriate activity of M. rectus femoris (RF) during swing is believed to contribute to stiff knee gait in cerebral palsy. This study used musculoskeletal modeling techniques to analyze rectus femoris musculo-tendon (MT) length and lengthening velocity during stiff knee gait in 35 children with diplegic cerebral palsy (CP). Duncan Ely test scores were used to categorize the patients into four groups with increasing levels of rectus femoris spasticity. Knee kinematics confirmed a significant reduction and delay of maximal peak knee flexion during swing in the patient groups compared to reference values. Maximal musculo-tendon length of M. rectus femoris was reduced and occurred prematurely in swing. Musculo-tendon lengthening velocity was significantly reduced and the timing of the maximal lengthening velocity was shifted into stance phase. The present study demonstrates altered dynamic behavior of the M. rectus femoris in stiff knee gait and the results indicate that maximal knee flexion in swing was not a valid reference for the MT length of the M. rectus femoris. Furthermore, in the patient group maximal musculo-tendon lengthening velocity of the muscle related to the stance phase rather than the stance-swing transition.

  9. Range of motion and leg rotation affect EMG activation levels of the superficial quadriceps muscles during leg extension.

    PubMed

    Signorile, Joseph F; Lew, Karen; Stoutenberg, Mark; Pluchino, Alessandra; Lewis, John E; Gao, Jinrun

    2014-06-30

    The leg extension (LE) is commonly used to strengthen the quadriceps muscles during training and rehabilitation. This study examined the effects of limb position (POS) and range of motion (ROM) on quadriceps electromyography (EMG) during 8 repetitions (REP) of LE. Twenty-four participants performed eight LE REP at their 8-repetition maximum with lower limbs medially rotated (TI), laterally rotated (TO), and neutral (NEU). Each REP EMG was averaged over the first, middle, and final 0.524 rad ROM. For vastus medialis oblique (VMO), a REP x ROM interaction was detected (p<0.02). The middle 0.524 rad produced significantly higher EMG than the initial 0.524 rad for REP 6-8 and the final 0.524 rad produced higher EMG than the initial 0.524 rad for REP 1, 2, 3, 4, 6, 8 (p<0.05). For rectus femoris (RF), EMG activity increased across REP with TO generating the greatest activity (p<0.001). For vastus lateralis (VL), EMG increased across REP (p<0.001) with NEU and TO EMG increasing linearly throughout ROM, and TI activity greatest during the middle 0.524 rad. We conclude that to target the VMO the optimal ROM is the final 1.047 rad regardless of POS, while maximum EMG for the RF is generated using TO regardless of ROM. In contrast, the VL is maximally activated using TI over the first 1.047 rad ROM or in NEU over the final 0.524 rad ROM.

  10. Strength Training to Contraction Failure Increases Voluntary Activation of the Quadriceps Muscle Shortly After Total Knee Arthroplasty

    PubMed Central

    Mikkelsen, Elin Karin; Jakobsen, Thomas Linding; Holsgaard-Larsen, Anders; Andersen, Lars Louis; Bandholm, Thomas

    2016-01-01

    ABSTRACT Objective The objective of this study was to investigate voluntary activation of the quadriceps muscle during one set of knee extensions performed until contraction failure in patients shortly after total knee arthroplasty. Design This was a cross-sectional study of 24 patients with total knee arthroplasty. One set of knee extensions was performed until contraction failure, using a predetermined 10 repetition maximum loading. In the operated leg, electromyographic (EMG) activity of the lateral and medial vastus, semitendinosus, and biceps femoris muscles was recorded during the set. Muscle activity (%EMGmax) and median power frequency of the EMG power spectrum were calculated for each repetition decile (10%–100% contraction failure). Results Muscle activity increased significantly over contractions from a mean of 90.0 and 93.6 %EMGmax (lateral vastus and medial vastus, respectively) at 10% contraction failure to 99.3 and 105.5 %EMGmax at 100% contraction failure (P = 0.009 and 0.004). Median power frequency decreased significantly over contractions from a mean of 66.8 and 64.2 Hz (lateral vastus and medial vastus, respectively) at 10% contraction failure to 59.9 and 60.1 Hz at 100% contraction failure (P = 0.0006 and 0.0187). Conclusion In patients shortly after total knee arthroplasty, 10 repetition maximum–loaded knee extensions performed in one set until contraction failure increases voluntary activation of the quadriceps muscle during the set. Clinical Trials Gov-identifier: NCT01713140 to the abstract to increase trial transparency. PMID:26339729

  11. Quadriceps-hamstring EMG activity during functional, closed kinetic chain exercise to fatigue.

    PubMed

    Pincivero, D M; Aldworth, C; Dickerson, T; Petry, C; Shultz, T

    2000-04-01

    It has been hypothesized that the ability of the neuromuscular system to co-contract muscles for joint stabilization may be impaired during the development of fatigue. The purpose of this study was to examine muscle activation of the quadriceps and hamstring muscles during a prolonged closed kinetic chain exercise, the forward lunge. Eight males and two females [mean (SD) age 26.0 (2.3) years, height 177.2 (13.6) cm, body mass 82.8 (17.1) kg] with no prior knee pathology volunteered for this study. Subjects performed repeated forward lunges onto their dominant leg at the cadence of one full lunge cycle every 2 s, until the point of volitional failure. Digital switches were positioned to record foot-strike and knee-strike of the lunge leg at the midpoint of the lunge, as well as heel-strike upon return to stance. During the lunge performance, surface electromyographic (EMG) signals of the vastus lateralis (VL), vastus medialis (VM), biceps femoris (BF), and semitendinosus (ST) muscles of the supporting leg were measured. Heart rate was also monitored every 30 s during the performance. All EMG data were full-wave rectified, partitioned into up and down phases, and integrated over the entire exercise period. The results demonstrated a significant increase in activation of the VL, VM, and BF during performance of the forward lunge to volitional failure (P < 0.05). No significant increase was shown for the ST. Heart rate increased significantly over the course of the lunge. These findings suggest that activation of the VL, VM, and BF muscles occurs as a unit during performance of the forward lunge during both concentric and eccentric lunge phases.

  12. Structure relates to elastic recoil and functional role in quadriceps tendon and patellar ligament.

    PubMed

    Franchi, Marco; Quaranta, Marilisa; Macciocca, Maria; De Pasquale, Viviana; Ottani, Vittoria; Ruggeri, Alessandro

    2009-04-01

    Tendons and ligaments have similar but slightly different structure and composition. Crimps of tendons and ligaments are morphological structures related to the elastic functional properties of these connective tissues. Aim of this study was to investigate the morphological arrangement of collagen fibres, fibrils and crimping pattern of suprapatellar (rectus femoris tendon-RFT and vastus intermedius tendon-VIT) and infrapatellar connective tissues (patellar ligament-PL) to relate their structural aspects to their common function role of leg extension. RFT, VIT and PL were removed from knees of Sprague-Dawley rats and light and electron microscopy (TEM and SEM) performed. Sagittal sections showed that collagen array and crimping pattern were similar in RFT and PL but differed from VIT. Morphometric analysis confirmed that crimp number was about the same in RFT and PL (5.4+/-1.4 and 6.1+/-2.8 respectively), but it was almost three times higher in VIT (14.5+/-4.7). Similarly crimp top angle in RFT and PL (141.5+/-15.0 degrees and 146.2+/-12.2 degrees respectively) was significantly higher than in VIT (122.3+/-14.8 degrees ) and the crimp base length was more than twice as wide in RFT (75.5+/-22.6microm) and PL (72.3+/-28.9microm) than in VIT (36+/-14.1microm). The smaller, fewer and most crimped crimps in VIT show that this tendon has a greater elastic recoil and responds to higher forces as among quadriceps muscles the vastus intermedius belly contributes the most during knee extension. By contrast, RFT acting as a "stopper" tendon also plays a ligament role by limiting an excessive flexion of the joint during postural rest position of the knee.

  13. Changes in Quadriceps Muscle Activity During Sustained Recreational Alpine Skiing

    PubMed Central

    Kröll, Josef; Müller, Erich; Seifert, John G.; Wakeling, James M.

    2011-01-01

    During a day of skiing thousands of repeated contractions take place. Previous research on prolonged recreational alpine skiing show that physiological changes occur and hence some level of fatigue is inevitable. In the present paper the effect of prolonged skiing on the recruitment and coordination of the muscle activity was investigated. Six subjects performed 24 standardized runs. Muscle activity during the first two (PREskiing) and the last two (POSTskiing) runs was measured from the vastus lateralis (VL) and rectus femoris (RF) using EMG and quantified using wavelet and principal component analysis. The frequency content of the EMG signal shifted in seven out of eight cases significantly towards lower frequencies with highest effects observed for RF on outside leg. A significant pronounced outside leg loading occurred during POSTskiing and the timing of muscle activity peaks occurred more towards turn completion. Specific EMG frequency changes were observed at certain time points throughout the time windows and not over the whole double turn. It is suggested that general muscular fatigue, where additional specific muscle fibers have to be recruited due to the reduced power output of other fibers did not occur. The EMG frequency decrease and intensity changes for RF and VL are caused by altered timing (coordination) within the turn towards a most likely more uncontrolled skiing technique. Hence, these data provide evidence to suggest recreational skiers alter their skiing technique before a potential change in muscle fiber recruitment occurs. Key points The frequency content of the EMG signal shifted in seven out of eight cases significantly towards lower frequencies with highest effects observed for RF. General muscular fatigue, where additional specific fibers have to be recruited due to the reduced power output of other fibers, did not occur. A modified skiing style towards a less functional and hence more uncontrolled skiing technique seems to be a key

  14. Quadratus femoris: An EMG investigation during walking and running.

    PubMed

    Semciw, Adam I; Freeman, Michael; Kunstler, Breanne E; Mendis, M Dilani; Pizzari, Tania

    2015-09-18

    Dysfunction of hip stabilizing muscles such as quadratus femoris (QF) is identified as a potential source of lower extremity injury during functional tasks like running. Despite these assumptions, there are currently no electromyography (EMG) data that establish the burst activity profile of QF during any functional task like walking or running. The objectives of this study were to characterize and compare the EMG activity profile of QF while walking and running (primary aim) and describe the direction specific action of QF (secondary aim). A bipolar fine-wire intramuscular electrode was inserted via ultrasound guidance into the QF of 10 healthy participants (4 females). Ensemble curves were generated from four walking and running trials, and normalized to maximum voluntary isometric contractions (MVICs). Paired t-tests compared the temporal and amplitude EMG variables. The relative activity of QF in the MVICs was calculated. The QF displayed moderate to high amplitude activity in the stance phase of walking and very high activity during stance in running. During swing, there was minimal QF activity recorded during walking and high amplitudes were present while running (run vs walk effect size=4.23, P<0.001). For the MVICs, external rotation and clam produced the greatest QF activity, with the hip in the anatomical position. This study provides an understanding of the activity demands placed on QF while walking and running. The high activity in late swing during running may signify a synergistic role with other posterior thigh muscles to control deceleration of the limb in preparation for stance.

  15. Exercise and Quadriceps Muscle Cooling Time

    PubMed Central

    Long, Blaine C; Cordova, Mitchell L; Brucker, Jody B; Demchak, Timothy J; Stone, Marcus B

    2005-01-01

    Context: Cryotherapy is commonly used for a variety of purposes; however, the body's response to cryotherapy immediately postexercise is unknown. Objective: To investigate the effect of prior exercise on crushed-ice–bag treatment of a large muscle group. Design: 2 × 3 repeated-measures design on depth (1 cm and 2 cm below adipose tissue) and treatment (exercise followed by ice, exercise followed by no ice, and no exercise followed by ice). Setting: Sports Injury Research Laboratory. Patients or Other Participants: Six physically active, uninjured male volunteers. Intervention(s): For the 2 exercise conditions, subjects rode a stationary cycle ergometer at 70% to 80% of their age-predicted maximum heart rate, as calculated by the Karvonen method. For the no-exercise condition, subjects lay supine on a treatment table. The cryotherapy treatment consisted of a 1-kg ice bag applied to the anterior mid thigh. For the no-ice condition, subjects lay supine on a treatment table. Main Outcome Measure(s): Time required for the intramuscular temperatures at the 1-cm and 2-cm depths below adipose tissue to return to pre-exercise baseline and time required to cool the 1-cm and 2-cm depths to 10°C below the pre-exercise temperature. Results: The time to cool the rectus femoris to the pre-exercise temperature using a crushed-ice–bag treatment was reduced by approximately 40 minutes (P < .001). The ice bag cooled the 1-cm and 2-cm depths to the pre-exercise temperature within 7 minutes (P = .38), but the 2-cm tissue depth took nearly 13.5 minutes longer to cool than the 1-cm depth when no ice was applied (P = .001). The 1-cm depth cooled to 10°C below the pre-exercise temperature about 8 minutes sooner than the 2-cm depth, regardless of whether the tissue was exercised or not (P < .001). Exercise shortened the cooling time to 10°C below the pre-exercise temperature by approximately 13 minutes (P = .05). Conclusions: Exercise before cooling with a crushed-ice bag enhanced

  16. Rectus femoris transfer and musculo-skeletal modeling: effect of surgical treatment on gait and on rectus femoris kinematics.

    PubMed

    Desailly, Eric; Khouri, Nejib; Sardain, Philippe; Yepremian, Daniel; Lacouture, Patrick

    2011-10-01

    Spasticity of the rectus femoris (RF) is one of the possible causes of stiff knee gait (SKG) in cerebral palsy. Musculoskeletal studies have shown that in SKG, length and speed of the RF are affected. No evaluation had been made to quantify the modifications of those parameters after surgery. The effect of this operation on gait quality and on RF kinematics was assessed in this study in order to identify kinematic patterns that may aid its diagnosis. For 26 transfers, clinical gait analysis pre- and post-surgery was used to compute the Gait Deviation Index (GDI) and Goldberg's index. The kinematics of the Original RF path (ORFp) was studied before and after surgery. The expression ORFp was chosen to avoid any confusion between this modeling parameter, whose computation was unchanged, and the actual anatomical path that was modified by surgery. The gait quality was improved (+18±12GDI) and there was an inverse relation between the pre-operative GDI and its improvement. The Golberg's index was improved (88% of the cases). The operation had a significant effect on the normalization of the timings of maximum length and speed of the ORFp. The improvement of SKG was correlated with the normalization of the timing of the ORFp's maximum length. The global improvement of the gait quality and of the SKG was demonstrated. Some parameters of muscular kinematics (RF length and velocity) have been standardized, showing an effect of the transfer not only during the swing, but also during stance. The premature timing of the ORFp peak length has been identified as a prognostic factor of a successful surgical outcome.

  17. Handgrip and quadriceps muscle endurance testing in young adults.

    PubMed

    White, Ciara; Dixon, Kimberley; Samuel, Dinesh; Stokes, Maria

    2013-01-01

    Grip strength is widely used for estimating whole body strength but there is a lack of information relating to grip endurance. Comparison between endurance of different muscle groups has received little attention. The main aim of the present study was to determine the endurance characteristics of hand grip and quadriceps muscles in healthy young adults and then to examine the association between fatigability of the two muscle groups. Twenty one healthy participants (8 males and 13 females) aged 18-35 years were studied. A maximal intermittent endurance test, consisting of 12 isometric contractions held for 3 seconds separated by 5 second rest periods, was utilised to measure muscle endurance. A Biodex isokinetic dynamometer and Jamar dynamometer were used to assess quadriceps and hand grip respectively. The mean of first (M1) and last (M2) three repetitions was calculated. Fatigue index values were calculated for both muscle groups by the 1st peak torque (PT) minus the last (12th) PT, divided by the 1st PT multiplied by 100. Quadriceps torque (M1:197.3 ± 65.2 Nm; M2:163.1 ± 47.6 Nm) and grip strength (M1:33.6 ± 9.9 Kg; M2:25.2 ± 8.1 Kg) both declined significantly during the 12 repetitions (p < 0.05). Hand grip showed a significantly higher mean fatigue index of 30% compared to 18% in the quadriceps (p < 0.05). Quadriceps showed better fatigability than hand grip. The findings therefore indicate caution against using grip endurance as a surrogate measure of quadriceps endurance. Further research is warranted to confirm observed differences between genders and to study endurance in different age groups.

  18. The Effect of Concentric Isokinetic Strength Training of the Quadriceps Femoris on Electromyography and Muscle Strength in the Trained and Untrained Limb.

    ERIC Educational Resources Information Center

    Evetovich, Tammy K.; Housh, Terry J.; Housh, Dona J.; Johnson, Glen O.; Smith, Douglas B.; Ebersole, Kyle T.

    2001-01-01

    Examined the effects of unilateral concentric isokinetic leg extension training on peak torque and electromyographic (EMG) responses in trained and untrained limbs. Adult men participated in training and control groups. Overall, unilateral concentric isokinetic strength training induced strength increases in trained as well as untrained limbs.…

  19. The Effect of Concentric Isokinetic Strength Training of the Quadriceps Femoris on Electromyography and Muscle Strength in the Trained and Untrained Limb.

    ERIC Educational Resources Information Center

    Evetovich, Tammy K.; Housh, Terry J.; Housh, Dona J.; Johnson, Glen O.; Smith, Douglas B.; Ebersole, Kyle T.

    2001-01-01

    Examined the effects of unilateral concentric isokinetic leg extension training on peak torque and electromyographic (EMG) responses in trained and untrained limbs. Adult men participated in training and control groups. Overall, unilateral concentric isokinetic strength training induced strength increases in trained as well as untrained limbs.…

  20. Evaluation of Central and Peripheral Fatigue in the Quadriceps Using Fractal Dimension and Conduction Velocity in Young Females

    PubMed Central

    Beretta-Piccoli, Matteo; D’Antona, Giuseppe; Barbero, Marco; Fisher, Beth; Dieli-Conwright, Christina M.; Clijsen, Ron; Cescon, Corrado

    2015-01-01

    Purpose Over the past decade, linear and non-linear surface electromyography descriptors for central and peripheral components of fatigue have been developed. In the current study, we tested fractal dimension (FD) and conduction velocity (CV) as myoelectric descriptors of central and peripheral fatigue, respectively. To this aim, we analyzed FD and CV slopes during sustained fatiguing contractions of the quadriceps femoris in healthy humans. Methods A total of 29 recreationally active women (mean age±standard deviation: 24±4 years) and two female elite athletes (one power athlete, age 24 and one endurance athlete, age 30 years) performed two knee extensions: (1) at 20% maximal voluntary contraction (MVC) for 30 s, and (2) at 60% MVC held until exhaustion. Surface EMG signals were detected from the vastus lateralis and vastus medialis using bidimensional arrays. Results Central and peripheral fatigue were described as decreases in FD and CV, respectively. A positive correlation between FD and CV (R=0.51, p<0.01) was found during the sustained 60% MVC, probably as a result of simultaneous motor unit synchronization and a decrease in muscle fiber CV during the fatiguing task. Conclusions Central and peripheral fatigue can be described as changes in FD and CV, at least in young, healthy women. The significant correlation between FD and CV observed at 60% MVC suggests that a mutual interaction between central and peripheral fatigue can arise during submaximal isometric contractions. PMID:25880369

  1. Effect of a Short Time Concentric Versus Eccentric Training Program on Electromyography Activity and Peak Torque of Quadriceps

    PubMed Central

    Carvalho, Alberto; Caserotti, Paolo; Carvalho, Carlos; Abade, Eduardo; Sampaio, Jaime

    2014-01-01

    The purpose of this study was to examine the effect of an 8-week concentric (CON) versus eccentric (ECC) isokinetic training program on the electromyography (EMG) signal amplitude of vastus medialis (VM), vastus lateralis (VL) and rectus femoris (RF). Also, the isometric (ISO) and dynamic maximum strength of the knee extensors were assessed. Eighteen physically healthy male subjects (age 22 ± 1 years, body height 177 ± 4 cm, body mass 73 ± 7 kg) performed four weeks of unilateral CON isokinetic training for the quadriceps of the dominant leg on a REV9000 dynamometer. At the end of the fourth week, the sample was divided into two groups, with one group performing additional four weeks of unilateral ECC training and the other continuing with CON training. The training sessions consisted of three sets of ten maximal repetitions at a velocity of 60ºs-1, three days per week for eight weeks. The results showed that CON and ECC groups improved the peak torque in all types of contractions. Also, both groups presented increases in the avgEMG for VL, VM and RF. The present investigation showed that CON training elicited increases of the ISO peak torque and VM avgEMG in the CON contraction. Additionally, significant gains were reported after the ECC training on the VM avgEMG in all contractions and RM avgEMG in CON contraction. PMID:25114726

  2. Evaluation of central and peripheral fatigue in the quadriceps using fractal dimension and conduction velocity in young females.

    PubMed

    Beretta-Piccoli, Matteo; D'Antona, Giuseppe; Barbero, Marco; Fisher, Beth; Dieli-Conwright, Christina M; Clijsen, Ron; Cescon, Corrado

    2015-01-01

    Over the past decade, linear and non-linear surface electromyography descriptors for central and peripheral components of fatigue have been developed. In the current study, we tested fractal dimension (FD) and conduction velocity (CV) as myoelectric descriptors of central and peripheral fatigue, respectively. To this aim, we analyzed FD and CV slopes during sustained fatiguing contractions of the quadriceps femoris in healthy humans. A total of 29 recreationally active women (mean age±standard deviation: 24±4 years) and two female elite athletes (one power athlete, age 24 and one endurance athlete, age 30 years) performed two knee extensions: (1) at 20% maximal voluntary contraction (MVC) for 30 s, and (2) at 60% MVC held until exhaustion. Surface EMG signals were detected from the vastus lateralis and vastus medialis using bidimensional arrays. Central and peripheral fatigue were described as decreases in FD and CV, respectively. A positive correlation between FD and CV (R=0.51, p<0.01) was found during the sustained 60% MVC, probably as a result of simultaneous motor unit synchronization and a decrease in muscle fiber CV during the fatiguing task. Central and peripheral fatigue can be described as changes in FD and CV, at least in young, healthy women. The significant correlation between FD and CV observed at 60% MVC suggests that a mutual interaction between central and peripheral fatigue can arise during submaximal isometric contractions.

  3. Effects of Barbell Deadlift Training on Submaximal Motor Unit Firing Rates for the Vastus Lateralis and Rectus Femoris

    PubMed Central

    Stock, Matt S.; Thompson, Brennan J.

    2014-01-01

    Previous investigations that have studied motor unit firing rates following strength training have been limited to small muscles, isometric training, or interventions involving exercise machines. We examined the effects of ten weeks of supervised barbell deadlift training on motor unit firing rates for the vastus lateralis and rectus femoris during a 50% maximum voluntary contraction (MVC) assessment. Twenty-four previously untrained men (mean age  = 24 years) were randomly assigned to training (n = 15) or control (n = 9) groups. Before and following the intervention, the subjects performed isometric testing of the right knee extensors while bipolar surface electromyographic signals were detected from the two muscles. The signals were decomposed into their constituent motor unit action potential trains, and motor units that demonstrated accuracy levels less than 92.0% were not considered for analysis. One thousand eight hundred ninety-two and 2,013 motor units were examined for the vastus lateralis and rectus femoris, respectively. Regression analyses were used to determine the linear slope coefficients (pulses per second [pps]/% MVC) and y-intercepts (pps) of the mean firing rate and firing rate at recruitment versus recruitment threshold relationships. Deadlift training significantly improved knee extensor MVC force (Cohen's d = .70), but did not influence force steadiness. Training had no influence on the slopes and y-intercepts for the mean firing rate and firing rate at recruitment versus recruitment threshold relationships. In agreement with previous cross-sectional comparisons and randomized control trials, our findings do not support the notion that strength training affects the submaximal control of motor units. PMID:25531294

  4. Acute effects of static stretching on peak and end-range hamstring-to-quadriceps functional ratios

    PubMed Central

    Sekir, Ufuk; Arabaci, Ramiz; Akova, Bedrettin

    2015-01-01

    AIM: To evaluate if static stretching influences peak and end-range functional hamstring-to-quadriceps (H/Q) strength ratios in elite women athletes. METHODS: Eleven healthy female athletes in an elite competitive level participated to the study. All the participants fulfilled the static stretching or non-stretching (control) intervention protocol in a randomized design on different days. Two static unassisted stretching exercises, one in standing and one in sitting position, were used to stretch both the hamstring and quadriceps muscles during these protocols. The total time for the static stretching was 6 ± 1 min. The isokinetic peak torque measurements for the hamstring and quadriceps muscles in eccentric and concentric modes and the calculations for the functional H/Q strength ratios at angular velocities of 60°/s and 180°/s were made before (pre) and after (post) the control or stretching intervention. The strength measurements and functional strength ratio calculations were based during the entire- and end-range of knee extension. RESULTS: The pre-test scores for quadriceps and hamstring peak torque and end range values were not significantly different between the groups (P > 0.05). Subsequently, although the control group did not exhibit significant changes in quadriceps and hamstring muscle strength (P > 0.05), static stretching decreased eccentric and concentric quadriceps muscle strength at both the 60°/s and 180°/s test speeds (P < 0.01). Similarly, static stretching also decreased eccentric and concentric hamstring muscle strength at both the 60°/s and 180°/s test speeds (P < 0.01). On the other hand, when the functional H/Q strength ratios were taken into consideration, the pre-intervention values were not significant different between the groups both during the entire and end range of knee extension (P > 0.05). Furthermore, the functional H/Q strength ratios exhibited no significant alterations during the entire and end ranges of knee extension

  5. Acute effects of static stretching on peak and end-range hamstring-to-quadriceps functional ratios.

    PubMed

    Sekir, Ufuk; Arabaci, Ramiz; Akova, Bedrettin

    2015-10-18

    To evaluate if static stretching influences peak and end-range functional hamstring-to-quadriceps (H/Q) strength ratios in elite women athletes. Eleven healthy female athletes in an elite competitive level participated to the study. All the participants fulfilled the static stretching or non-stretching (control) intervention protocol in a randomized design on different days. Two static unassisted stretching exercises, one in standing and one in sitting position, were used to stretch both the hamstring and quadriceps muscles during these protocols. The total time for the static stretching was 6 ± 1 min. The isokinetic peak torque measurements for the hamstring and quadriceps muscles in eccentric and concentric modes and the calculations for the functional H/Q strength ratios at angular velocities of 60°/s and 180°/s were made before (pre) and after (post) the control or stretching intervention. The strength measurements and functional strength ratio calculations were based during the entire- and end-range of knee extension. The pre-test scores for quadriceps and hamstring peak torque and end range values were not significantly different between the groups (P > 0.05). Subsequently, although the control group did not exhibit significant changes in quadriceps and hamstring muscle strength (P > 0.05), static stretching decreased eccentric and concentric quadriceps muscle strength at both the 60°/s and 180°/s test speeds (P < 0.01). Similarly, static stretching also decreased eccentric and concentric hamstring muscle strength at both the 60°/s and 180°/s test speeds (P < 0.01). On the other hand, when the functional H/Q strength ratios were taken into consideration, the pre-intervention values were not significant different between the groups both during the entire and end range of knee extension (P > 0.05). Furthermore, the functional H/Q strength ratios exhibited no significant alterations during the entire and end ranges of knee extension both in the static

  6. Giant pseudocyst of the rectus femoris muscle--repetitive strain injury in recreational soccer player.

    PubMed

    Cicvarić, Tedi; Lucin, Ksenija; Roth, Sandor; Ivancić, Aldo; Marinović, Marin; Santić, Veljko

    2010-04-01

    We report a case of a traumatic pseudocyst, in a recreational soccer player, after rupture of rectus femoris muscle. 37-year-old male, with history of repetitive painful accidents, was examined because of a double fist-sized mass in the anterior thigh. Ultrasound examination revealed a cystic mass in the rectus femoris muscle. Surgical removal of the mass and proximal remnant of muscle was done. Primary healing and functional recovery was achieved. Histological analysis revealed pseudocyst filled with degenerating clot and surrounded with thick fibrous capsule. The repetitive strain muscle injury, with prolonged period of healing, can occur like pseudocyst.

  7. Central and peripheral quadriceps fatigue in congestive heart failure☆

    PubMed Central

    Hopkinson, Nicholas S.; Dayer, Mark J.; Antoine-Jonville, Sophie; Swallow, Elisabeth B.; Porcher, Raphael; Vazir, Ali; Poole-Wilson, Philip; Polkey, Michael I.

    2013-01-01

    Aims The clinical syndrome of heart failure includes exercise limitation that is not directly linked to measures of cardiac function. Quadriceps fatigability may be an important component of this and this may arise from peripheral or central factors. Methods and results We studied 10 men with CHF and 10 healthy age-matched controls. Compared with a rest condition, 10 min after incremental maximal cycle exercise, twitch quadriceps force in response to supramaximal magnetic femoral nerve stimulation fell in both groups (CHF 14.1% ± 18.1%, p = 0.037; Control: 20.8 ± 11.0%, p < 0.001; no significant difference between groups). There was no significant change in quadriceps maximum voluntary contraction voluntary force. The difference in the motor evoked potential (MEP) response to transcranial magnetic stimulation of the motor cortex between rest and exercise conditions at 10 min, normalised to the peripheral action potential, also fell significantly in both groups (CHF: 27.3 ± 38.7%, p = 0.037; Control: 41.1 ± 47.7%, p = 0.024). However, the fall in MEP was sustained for a longer period in controls than in patients (p = 0.048). Conclusions The quadriceps is more susceptible to fatigue, with a similar fall in TwQ occurring in CHF patients at lower levels of exercise. This is associated with no change in voluntary activation but a lesser degree of depression of quadriceps motor evoked potential. PMID:22795722

  8. Functional changes of human quadriceps muscle injured by eccentric exercise.

    PubMed

    Serrão, F V; Foerster, B; Spada, S; Morales, M M B; Monteiro-Pedro, V; Tannús, A; Salvini, T F

    2003-06-01

    The present study evaluated functional changes of quadriceps muscle after injury induced by eccentric exercise. Maximal isometric torque of quadriceps and the surface electromyography (root mean square, RMS, and median frequency, MDF) of the vastus medialis oblique (VMO) and vastus lateralis (VL) muscles were examined before, immediately after and during the first 7 days after injury. Serum creatine kinase (CK) levels and magnetic resonance imaging (MRI) were used to identify muscle injury. The subject was used as her own control and percent refers to pre-injury data. Experiments were carried out with a sedentary 23-year-old female. Injury was induced by 4 bouts of 15 maximal isokinetic eccentric contractions (angular velocity of 5 /s; range of motion from 40 to 110 of knee flexion). The isometric torque of the quadriceps (knee at 90 flexion) decreased 52% immediately after eccentric exercise and recovered on the 5th day. The highest reduction of RMS occurred on the 2nd day after injury in both VL (63%) and VMO (66%) and only VL recovered to the pre-injury level on the 7th day. Immediately after injury, the MDF decreased by 5 and 3% (VMO and VL, respectively) and recovered one day later. Serum CK levels increased by 109% on the 2nd day and were still increased by 32% on the 7th day. MRI showed large areas of injury especially in the deep region of quadriceps. In conclusion, eccentric exercise decreased the isometric torque and electromyographic signals of quadriceps muscle, which were recovered in one week, despite the muscle regeneration signals.

  9. Quadriceps Activation Following Knee Injuries: A Systematic Review

    PubMed Central

    Hart, Joseph M.; Pietrosimone, Brian; Hertel, Jay; Ingersoll, Christopher D.

    2010-01-01

    Abstract Context: Arthrogenic muscle inhibition is an important underlying factor in persistent quadriceps muscle weakness after knee injury or surgery. Objective: To determine the magnitude and prevalence of volitional quadriceps activation deficits after knee injury. Data Sources: Web of Science database. Study Selection: Eligible studies involved human participants and measured quadriceps activation using either twitch interpolation or burst superimposition on patients with knee injuries or surgeries such as anterior cruciate ligament deficiency (ACLd), anterior cruciate ligament reconstruction (ACLr), and anterior knee pain (AKP). Data Extraction: Means, measures of variability, and prevalence of quadriceps activation (QA) failure (<95%) were recorded for experiments involving ACLd (10), ACLr (5), and AKP (3). Data Synthesis: A total of 21 data sets from 18 studies were initially identified. Data from 3 studies (1 paper reporting data for both ACLd and ACLr, 1 on AKP, and the postarthroscopy paper) were excluded from the primary analyses because only graphical data were reported. Of the remaining 17 data sets (from 15 studies), weighted mean QA in 352 ACLd patients was 87.3% on the involved side, 89.1% on the uninvolved side, and 91% in control participants. The QA failure prevalence ranged from 0% to 100%. Weighted mean QA in 99 total ACLr patients was 89.2% on the involved side, 84% on the uninvolved side, and 98.5% for the control group, with prevalence ranging from 0% to 71%. Thirty-eight patients with AKP averaged 78.6% on the involved side and 77.7% on the contralateral side. Bilateral QA failure was commonly reported in patients. Conclusions: Quadriceps activation failure is common in patients with ACLd, ACLr, and AKP and is often observed bilaterally. PMID:20064053

  10. Acute calcific tendinitis of the rectus femoris associated with intraosseous involvement: a case report with serial CT and MRI findings.

    PubMed

    Kim, Young Sung; Lee, Ho Min; Kim, Jong Pil

    2013-11-01

    Acute calcific tendinitis of the shoulder is a well-known condition, but it is rare in the rectus femoris origin. Mostly reported cases were occurred in the reflected head of the rectus femoris, and only few cases were in the direct head of the rectus femoris. Intraosseous marrow involvement of calcific tendinitis is a more rare condition; it often goes misdiagnosed as an infection or a neoplasm. We report a rare, unusual case of acute calcific tendinitis of the direct head of the rectus femoris associated with intraosseous marrow involvement of calcification in anterior inferior iliac spine with serial CT and MRI findings. Aggressive osseous change may occur in acute calcific tendinitis of the rectus femoris as in this case which should be made an appropriate diagnosis to avoid unnecessary investigation and overtreatment like a surgery.

  11. Shear-Wave Elastography Assessments of Quadriceps Stiffness Changes prior to, during and after Prolonged Exercise: A Longitudinal Study during an Extreme Mountain Ultra-Marathon

    PubMed Central

    Andonian, Pierre; Viallon, Magalie; Le Goff, Caroline; de Bourguignon, Charles; Tourel, Charline; Morel, Jérome; Giardini, Guido; Gergelé, Laurent; Millet, Grégoire P.; Croisille, Pierre

    2016-01-01

    In sports medicine, there is increasing interest in quantifying the elastic properties of skeletal muscle, especially during extreme muscular stimulation, to improve our understanding of the impact of alterations in skeletal muscle stiffness on resulting pain or injuries, as well as the mechanisms underlying the relationships between these parameters. Our main objective was to determine whether real-time shear-wave elastography (SWE) can monitor changes in quadriceps muscle elasticity during an extreme mountain ultra-marathon, a powerful mechanical stress model. Our study involved 50 volunteers participating in an extreme mountain marathon (distance: 330 km, elevation: +24,000 m). Quantitative SWE velocity and shear modulus measurements were performed in most superficial quadriceps muscle heads at the following 4 time points: before the race, halfway through the race, upon finishing the race and after recovery (+48 h). Blood biomarker levels were also measured. A significant decrease in the quadriceps shear modulus was observed upon finishing the race (3.31±0.61 kPa) (p<0.001) compared to baseline (3.56±0.63 kPa), followed by a partial recovery +48 h after the race (3.45±0.6 kPa) (p = 0.002) across all muscle heads, as well as for each of the following three muscle heads: the rectus femoris (p = 0.003), the vastus medialis (p = 0.033) and the vastus lateralis (p = 0.001). Our study is the first to assess changes in muscle stiffness during prolonged extreme physical endurance exercises based on shear modulus measurements using non-invasive SWE. We concluded that decreases in stiffness, which may have resulted from quadriceps overuse in the setting of supra-physiological stress caused by the extreme distance and unique elevation of the race, may have been responsible for the development of inflammation and muscle swelling. SWE may hence represent a promising tool for monitoring physiologic or pathological variations in muscle stiffness and may be useful for

  12. Shear-Wave Elastography Assessments of Quadriceps Stiffness Changes prior to, during and after Prolonged Exercise: A Longitudinal Study during an Extreme Mountain Ultra-Marathon.

    PubMed

    Andonian, Pierre; Viallon, Magalie; Le Goff, Caroline; de Bourguignon, Charles; Tourel, Charline; Morel, Jérome; Giardini, Guido; Gergelé, Laurent; Millet, Grégoire P; Croisille, Pierre

    2016-01-01

    In sports medicine, there is increasing interest in quantifying the elastic properties of skeletal muscle, especially during extreme muscular stimulation, to improve our understanding of the impact of alterations in skeletal muscle stiffness on resulting pain or injuries, as well as the mechanisms underlying the relationships between these parameters. Our main objective was to determine whether real-time shear-wave elastography (SWE) can monitor changes in quadriceps muscle elasticity during an extreme mountain ultra-marathon, a powerful mechanical stress model. Our study involved 50 volunteers participating in an extreme mountain marathon (distance: 330 km, elevation: +24,000 m). Quantitative SWE velocity and shear modulus measurements were performed in most superficial quadriceps muscle heads at the following 4 time points: before the race, halfway through the race, upon finishing the race and after recovery (+48 h). Blood biomarker levels were also measured. A significant decrease in the quadriceps shear modulus was observed upon finishing the race (3.31±0.61 kPa) (p<0.001) compared to baseline (3.56±0.63 kPa), followed by a partial recovery +48 h after the race (3.45±0.6 kPa) (p = 0.002) across all muscle heads, as well as for each of the following three muscle heads: the rectus femoris (p = 0.003), the vastus medialis (p = 0.033) and the vastus lateralis (p = 0.001). Our study is the first to assess changes in muscle stiffness during prolonged extreme physical endurance exercises based on shear modulus measurements using non-invasive SWE. We concluded that decreases in stiffness, which may have resulted from quadriceps overuse in the setting of supra-physiological stress caused by the extreme distance and unique elevation of the race, may have been responsible for the development of inflammation and muscle swelling. SWE may hence represent a promising tool for monitoring physiologic or pathological variations in muscle stiffness and may be useful for

  13. Muscle Activation Profiles and Co-Activation of Quadriceps and Hamstring Muscles around Knee Joint in Indian Primary Osteoarthritis Knee Patients.

    PubMed

    Sharma, Sanjeev Kumar; Yadav, Shiv Lal; Singh, U; Wadhwa, Sanjay

    2017-05-01

    Osteoarthritis (OA) of knee is a common joint disease. It is associated with reduced knee joint stability due to impaired quadriceps strength, pain, and an altered joint structure. There is altered muscle activation in knee OA patients, which interferes with normal load distribution around the knee and facilitates disease progression. Our primary aim was to determine activation patterns of the muscles i.e., quadriceps and hamstrings in knee OA patients during walking. We also studied co-activation of muscles around knee joint in primary OA knee patients including directed medial and lateral co-contractions. This observational study was done at Department of Physical Medicine and Rehabilitation, All India Institute of Medical Sciences, New Delhi, India. Fourty-four patients with medial compartment primary knee OA were included in study after satisfying inclusion and exclusion criteria. All the patients were assessed for mean, peak and integrated Root Mean Square (RMS), EMG values, muscle activation patterns and co-activation of muscles around knee joint by surface Electromyography (EMG) analysis of Vastus Medialis Obliques (VMO), Vastus Lateralis (VL), Semitendinosus (SMT) and Biceps Femoris (BF) muscles during gait cycle. The EMG waveform for each muscle was amplitude normalized and time normalized to 100% of gait cycle and plotted on graph. Quantitative variables were assessed for normal distribution and accordingly mean±SD or median (range), as appropriate, was computed. For primary OA knee, mean age 61±5 years, mean weight 63.7±10.1 kg, mean height 153.9±7.2 cm, and mean Body Mass Index (BMI) 26.8±3.0 kg/m(2) was found. The muscle activity of hamstrings (SMT muscle and BF) was increased during midstance, late stance and early swing phase of gait cycle as compared to quadriceps (VMO and VL) muscle activity respectively, suggesting co-contraction of opposing muscles around knee joint. Patients with knee OA walk with increased hamstring muscle activity (during

  14. Quantifying Quadriceps Muscle Strength in Patients With ACL Injury, Focal Cartilage Lesions, and Degenerative Meniscus Tears

    PubMed Central

    Eitzen, Ingrid; Grindem, Hege; Nilstad, Agnethe; Moksnes, Håvard; Risberg, May Arna

    2016-01-01

    Background: Reduced quadriceps strength influences knee function and increases the risk of knee osteoarthritis. Thus, it is of significant clinical relevance to precisely quantify strength deficits in patients with knee injuries. Purpose: To evaluate isokinetic concentric quadriceps muscle strength torque values, assessed both from peak torque and at specific knee flexion joint angles, in patients with anterior cruciate ligament (ACL) injury, focal cartilage lesions, and degenerative meniscus tears. Study Design: Cohort study; Level of evidence, 3. Methods: Data were synthesized from patients included in 3 previously conducted research projects: 2 prospective cohort studies and 1 randomized controlled trial. At the time of inclusion, all patients were candidates for surgery. Isokinetic concentric quadriceps muscle strength measurements (60 deg/s) were performed at baseline (preoperative status) and after a period of progressive supervised exercise therapy (length of rehabilitation period: 5 weeks for ACL injury, 12 weeks for cartilage lesions and degenerative meniscus). Outcome measures were peak torque and torque at specific knee flexion joint angles from 20° to 70°. All patients had unilateral injuries, and side-to-side deficits were calculated. For comparisons between and within groups, we utilized 1-way analysis of variance and paired t tests, respectively. Results: In total, 250 patients were included. At baseline, cartilage patients had the most severe deficit (39.7% ± 24.3%; P < .001). Corresponding numbers for ACL and degenerative meniscus subjects were 21.7% (±13.2%) and 20.7% (±16.3%), respectively. At retest, there was significant improvement in all groups (P < .001), with remaining deficits of 24.7% (±18.5%) for cartilage, 16.8% (±13.9%) for ACL, and 3.3% (±17.8%) for degenerative meniscus. Peak torque was consistently measured at 60° of knee flexion, whereas the largest mean deficits were measured at 30° at baseline and 70° at retest for the

  15. Effect of Prior Injury on Changes to Biceps Femoris Architecture across an Australian Football League Season.

    PubMed

    Timmins, Ryan G; Bourne, Matthew N; Hickey, Jack T; Maniar, Nirav; Tofari, Paul J; Williams, Morgan D; Opar, David A

    2017-10-01

    To assess in-season alterations of biceps femoris long head (BFlh) fascicle length in elite Australian footballers with and without a history of unilateral hamstring strain injury (HSI) in the past 12 months. Thirty elite Australian football players were recruited. Twelve had a history of unilateral HSI. Eighteen had no HSI history. All had their BFlh architecture assessed at approximately monthly intervals, six times across a competitive season. The previously injured limb's BFlh fascicles increased from the start of the season and peaked at week 5. Fascicle length gradually decreased until the end of the season, where they were shortest. The contralateral uninjured limb's fascicles were the longest when assessed at week 5 and showed a reduction in-season where weeks 17 and 23 were shorter than week 1. Control group fascicles were longest at week 5 and reduced in-season. The previously injured limb's BFlh fascicles were shorter than the control group at all weeks and the contralateral uninjured limb at week 5. Compared with the control group, the contralateral uninjured limb had shorter fascicles from weeks 9 to 23. Athletes with a history of HSI end the season with shorter fascicles than they start. Limbs without a history of HSI display similar BFlh fascicle lengths at the end of the season as they begin with. All athletes increase fascicle length at the beginning of the season; however, the extent of the increase differed based on history of HSI. These findings show that a HSI history may influence structural adaptation of the BFlh in-season.

  16. Quadriceps Muscle Function After Exercise in Men and Women With a History of Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Kuenze, Christopher M.; Hertel, Jay; Hart, Joseph M.

    2014-01-01

    Context: Sex differences in lower extremity neuromuscular function have been reported after anterior cruciate ligament reconstruction (ACLR). Research evidence supports different levels of fatigability in men and women and between patients with ACLR and healthy controls. The influence of sex on the response to continuous exercise in patients with ACLR is not clear. Objective: To compare quadriceps neuromuscular function after exercise between men and women with ACLR. Design: Descriptive laboratory study. Setting: Laboratory. Patients or Other Participants: Twenty-six active volunteers (13 men [50%]: age = 24.1 ± 4.4 years, height = 179.1 ± 9.8 cm, mass = 80.1 ± 9.4 kg, months since surgery = 43.5 ± 37.0; 13 women [50%]: age = 24.2 ± 5.6 years, height = 163.0 ± 5.9 cm, mass = 62.3 ± 8.3 kg, months since surgery = 45.8 ± 42.7) with a history of unilateral primary ACLR at least 6 months earlier. Intervention(s): Thirty minutes of continuous exercise comprising 5 separate 6-minute cycles, including 5 minutes of uphill walking and 1 minute of body-weight squatting and step-ups. Main Outcome Measure(s): Normalized knee-extension maximal voluntary isometric contraction torque, quadriceps superimposed-burst torque, and quadriceps central activation ratio before and after exercise. We performed separate 2 (sex: men, women) × 2 (time: preexercise, postexercise) repeated-measures analyses of variance for the 3 variables. Separate, independent-samples t tests were calculated to compare preexercise with postexercise change in all dependent variables between sexes. Results: A significant group-by-time interaction was present for knee-extension torque (P = .04). The percentage reduction in knee-extension maximal voluntary isometric contraction torque (men = 1.94%, women = −10.32%; P = .02) and quadriceps central activation ratio (men = −1.45%, women = −8.69%; P = .03) experienced by men was less than that observed in women. Conclusions: In the presence of

  17. Quadriceps muscle function after exercise in men and women with a history of anterior cruciate ligament reconstruction.

    PubMed

    Kuenze, Christopher M; Hertel, Jay; Hart, Joseph M

    2014-01-01

    Sex differences in lower extremity neuromuscular function have been reported after anterior cruciate ligament reconstruction (ACLR). Research evidence supports different levels of fatigability in men and women and between patients with ACLR and healthy controls. The influence of sex on the response to continuous exercise in patients with ACLR is not clear. To compare quadriceps neuromuscular function after exercise between men and women with ACLR. Descriptive laboratory study. Laboratory. Twenty-six active volunteers (13 men [50%]: age = 24.1 ± 4.4 years, height = 179.1 ± 9.8 cm, mass = 80.1 ± 9.4 kg, months since surgery = 43.5 ± 37.0; 13 women [50%]: age = 24.2 ± 5.6 years, height = 163.0 ± 5.9 cm, mass = 62.3 ± 8.3 kg, months since surgery = 45.8 ± 42.7) with a history of unilateral primary ACLR at least 6 months earlier. Thirty minutes of continuous exercise comprising 5 separate 6-minute cycles, including 5 minutes of uphill walking and 1 minute of body-weight squatting and step-ups. Normalized knee-extension maximal voluntary isometric contraction torque, quadriceps superimposed-burst torque, and quadriceps central activation ratio before and after exercise. We performed separate 2 (sex: men, women) × 2 (time: preexercise, postexercise) repeated-measures analyses of variance for the 3 variables. Separate, independent-samples t tests were calculated to compare preexercise with postexercise change in all dependent variables between sexes. A significant group-by-time interaction was present for knee-extension torque (P = .04). The percentage reduction in knee-extension maximal voluntary isometric contraction torque (men = 1.94%, women = -10.32%; P = .02) and quadriceps central activation ratio (men = -1.45%, women = -8.69%; P = .03) experienced by men was less than that observed in women. In the presence of quadriceps dysfunction, female participants experienced greater-magnitude reductions in quadriceps function after 30 minutes of exercise than male

  18. Quadriceps tendon injuries in national football league players.

    PubMed

    Boublik, Martin; Schlegel, Theodore F; Koonce, Ryan C; Genuario, James W; Kinkartz, Jason D

    2013-08-01

    Distal quadriceps tendon tears are uncommon injuries that typically occur in patients older than 40 years of age, and they have a guarded prognosis. Predisposing factors, prodromal findings, mechanisms of injury, treatment guidelines, and recovery expectations are not well described in high-level athletes. Professional American football players with an isolated tear of the quadriceps tendon treated with timely surgical repair will return to their sport. Case series; Level of evidence, 4. Fourteen unilateral distal quadriceps tendon tears were identified in National Football League (NFL) players from 1994 to 2004. Team physicians retrospectively reviewed training room and clinic records, operative notes, and imaging studies for each of these players. Data on each player were analyzed to identify variables predicting return to play. A successful outcome was defined as returning to play in regular-season NFL games. Eccentric contraction of the quadriceps was the most common mechanism of injury, occurring in 10 players. Only 1 player had antecedent ipsilateral extensor mechanism symptoms. Eleven players had a complete rupture of the quadriceps tendon, and 3 had partial tears. There were no associated knee injuries. All ruptures were treated with surgical repair, 1 of which was delayed after failure of nonoperative treatment. Fifty percent of players returned to play in regular-season NFL games. There was a trend toward earlier draft status for those who returned to play compared with those who did not (draft round, 3.1 ± 2.5 vs. 6.0 ± 2.9, respectively; P = .073). For those who returned to play, the average number of games after injury was 40.9 (range, 12-92). Quadriceps tendon tears are rare in professional American football players, and they usually occur from eccentric load on the extensor mechanism. Prodromal symptoms and predisposing factors are usually absent. Even with timely surgical repair, there is a low rate of return to play in regular-season games. There

  19. Rabbit rectus femoris muscle for ischemia-reperfusion studies: an improved model.

    PubMed

    Hoballah, J J; Mohan, C R; Schipper, P H; Chalmers, R T; Corry, D C; Corson, J D

    1996-11-01

    The rabbit rectus femoris muscle was evaluated as a potential model for skeletal muscle reperfusion injury studies. Six white New Zealand rabbits were used. On one randomly selected hind limb, ischemia was induced by direct clamping of the rectus femoris muscle's vascular pedicle. On the other side, blood flow was interrupted by clamping the femoral artery above and below the origin of the vascular pedicle that supplies the rectus femoris muscle. The duration of normothermic ischemia was 4 hr and was followed by 24 hr of normothermic reperfusion. The interruption and restoration of blood flow was monitored using a laser flow meter. The rectus femoris muscles were weighed on a suspension spring balance prior to ischemia and at the end of reperfusion to estimate edema. The extent of muscle necrosis was determined using planimetry following staining with nitroblue tetrazolium. The muscle necrosis obtained by direct clamping of the vascular pedicle (66.9 +/- 14.3%) was significantly greater than that obtained by indirect clamping (18.6 +/- 11.4%) (P < 0.03 by t test). Unlike the indirect clamping technique, direct clamping achieved a good magnitude of muscle necrosis, thus allowing that specific model to be used in skeletal muscle reperfusion injury studies. The muscle weight gain observed in the direct clamping muscle group was 19.8 +/- 9.0% and was significantly greater than that observed in the opposite group being 6.3 +/- 6.5% (P < 0.05 by t test). The rabbit rectus femoris muscle is a suitable model for evaluating skeletal muscle reperfusion injury provided that direct clamping of the vascular pedicle is utilized.

  20. Hip Strength in Patients with Quadriceps Strength Deficits after ACL Reconstruction.

    PubMed

    Bell, David R; Trigsted, Stephanie M; Post, Eric G; Walden, Courtney E

    2016-10-01

    Quadriceps strength deficits persist for years after anterior cruciate ligament (ACL) reconstruction, and patients with these deficits often shift torque demands away from the knee extensors to the hip during functional tasks. However, it is not clear how quadriceps strength deficits may affect hip strength. Therefore, the purpose of this study was to investigate differences in lower extremity strength in individuals with ACL reconstruction with differing levels of quadriceps strength asymmetry. Isometric strength was recorded bilaterally in 135 participants (73 control and 62 with unilateral ACL reconstruction, time from surgery = 30.9 ± 17.6 months) from the knee extensors and flexors, hip extensors and abductors, and hip internal and external rotator muscle groups. Symmetry indices (limb symmetry index (LSI)) were created based on quadriceps strength, and subjects with ACL reconstruction were subdivided (high quadriceps (LSI ≥ 90%), n = 37; low quadriceps (LSI < 85%), n = 18). Individual group (control vs high quadriceps vs low quadriceps) by limb (reconstructed/nondominant vs healthy/dominant) repeated-measures ANOVA was used to compare strength (%BW) for each of the six joint motions of interest (knee extensors/flexors, hip abductors/extensors/external, and internal rotators) while controlling for time from surgery. An interaction was observed for quadriceps strength (P < 0.001), and the reconstructed limb in the low quadriceps group was weaker than all other limbs. A main effect for group was observed with the low quadriceps group having greater hip extension (P = 0.007) strength in both limbs compared with the other groups. Knee flexion strength was weaker in the reconstructed limb of the high quadriceps group (P = 0.047) compared with all other groups and limbs. Individuals with ACL reconstruction and involved limb quadriceps weakness have greater hip extension strength in both limbs compared with patients with bilateral strength symmetry and controls.

  1. Quadriceps Muscles O2 Extraction and EMG Breakpoints during a Ramp Incremental Test.

    PubMed

    Iannetta, Danilo; Qahtani, Ahmad; Millet, Guillaume Y; Murias, Juan M

    2017-01-01

    Muscle deoxygenated breakpoint ([HHb]BP) has been found to be associated with other indices of exercise tolerance in the vastus lateralis (VL) muscle but not in the vastus medialis (VM) and rectus femoris (RF). Purpose: To investigate whether the [HHb]BP occurs also in the VM and RF muscles and whether or not it is associated with other physiological indices of exercise tolerance, such as the EMG threshold (EMGt) and the respiratory compensation point (RCP). Methods: Twelve young endurance trained participants performed maximal ramp incremental (RI) cycling tests (25-30 W·min(-1) increments). Muscle oxygen extraction and activity as well as ventilatory and gas exchange parameters were measured. After accounting for the mean response time, the oxygen uptake ([Formula: see text]O2) corresponding to the RCP, [HHb]BP, and the EMGt was determined. Results: Peak power output (POpeak) was 359 ± 48 W. Maximal oxygen consumption ([Formula: see text]O2max) was 3.87 ± 0.46 L·min(-1). The [Formula: see text]O2 at the RCP was 3.39 ± 0.41 L·min(-1). The [Formula: see text]O2 (L·min(-1)) corresponding to the [HHb]BP and EMGt were: 3.49 ± 0.46 and 3.40 ± 0.44; 3.44 ± 0.61 and 3.43 ± 0.49; 3.59 ± 0.52, and 3.48 ± 0.46 for VL, VM, and RF, respectively. Pearson's correlation between these thresholds ranged from 0.90 to 0.97 (P < 0.05). No difference was found for the absolute [Formula: see text]O2 and the normalized PO (%) at which the thresholds occurred in all three muscles investigated (P > 0.05). Although in eight out of 12 participants, the [HHb]BP in the RF led to a steeper increase instead of leading to a plateau-like response as observed in the VL and VM, the [Formula: see text]O2 at the breakpoints still coincided with that at the RCP. Conclusions: This study demonstrated that local indices of exercise tolerance derived from different portions of the quadriceps are not different to the systemic index of the RCP.

  2. Patellar tendon straps decrease pre-landing quadriceps activation in males with patellar tendinopathy.

    PubMed

    Rosen, Adam B; Ko, Jupil; Simpson, Kathy J; Brown, Cathleen N

    2017-03-01

    To determine if patellar tendon straps altered quadriceps' muscle activity during a drop-jump landing in males with and without patellar tendinopathy. Case-control. Biomechanics Research Laboratory. Twenty recreationally-active males participated: ten (age = 21.3 ± 2.4 years, height = 182.8 ± 5.3 cm, mass = 81.7 ± 8.6 kg) with patellar tendinopathy; ten (age = 22.0 ± 1.6 years, height = 185.7 ± 4.5 cm, mass = 82.2 ± 9.8 kg) were healthy with no history of tendinopathy. Electromyography (EMG) data for the vastus medialis (VM), rectus femoris (RF), and vastus lateralis (VL) muscles were collected. Five 2-legged 40 cm drop-jumps were performed wearing a patellar tendon strap and 5 with no-strap in a counterbalanced order. Root-mean square EMG (REMG) values of the VM, RF, and VL were averaged for a pre-landing and post-landing interval. Multiple mixed-model two-way ANOVAs were performed to determine the effect of tendinopathy and strapping condition on REMG values for each muscle. For the pre-landing interval, all participants displayed lesser VL EMG activation (0.44 ± 0.19%, 0.53 ± 0.27%, respectively; p = 0.007, d = 0.39) in the no-strap compared with the strap condition. When wearing a strap, all participants demonstrated lower VL activation prior to landing which may be helpful in reducing tensile stress at the tendon. These effects may be clinically important in modulating pain in those with patellar tendinopathy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Inhibition of the quadriceps muscles in elite male volleyball players.

    PubMed

    Huber, A; Suter, E; Herzog, W

    1998-04-01

    Inhibition of the quadriceps muscles was assessed in 13 elite male volleyball players using the interpolated twitch technique. This technique involves applying an electrical stimulus to the voluntarily contracted quadriceps muscles to estimate the number of motor units not fully activated during the contraction. Knee extensor moments and muscle inhibition were measured during isometric contractions at knee angles of 30 degrees and 60 degrees from full extension. A medical history of knee joint injury and pain experienced in the knee during testing were assessed. Previous knee joint injury did not affect the knee extensor moments, but produced a difference in muscle inhibition: muscle inhibition in legs with previous injuries was significantly lower than muscle inhibition in legs with no previous injury. Moderate pain in the knee during testing did not affect muscle inhibition, but was associated with reduced knee extensor moments. We consider that the loss in knee extensor moments associated with pain might be caused by atrophy of the quadriceps muscles as a consequence of the disrupted training routine. The lower muscle inhibition in volleyball players with previous injury suggested that the intense rehabilitation programme that these athletes undergo after knee injury improves muscle activation. As a result, athletes with previous knee joint injuries were able to produce the same knee extensor moments as athletes with no previous injury, probably because of their ability to recruit the available motor units more completely. This recruitment may compensate for the possible loss in muscle mass encountered during the period of injury and detraining.

  4. Effect of Knee Position on Quadriceps Muscle Force Steadiness and Activation Strategies

    PubMed Central

    Krishnan, Chandramouli; Allen, Eric J.; Williams, Glenn N.

    2010-01-01

    Introduction This study investigated the effect of knee position on quadriceps force steadiness and activation strategies. Methods Quadriceps force steadiness was evaluated in twenty-two volunteers at two knee positions by testing their ability to regulate submaximal force. Muscle activation strategies were studied in both time and frequency domains using surface electromyography. Results Quadriceps force fluctuations and the associated agonist and antagonist activity were significantly higher at 90° than at 30° of flexion (P < 0.05). The quadriceps median frequency recorded at 30° was significantly higher than at 90° of flexion (P < 0.05). Regression analyses revealed that force steadiness was related to quadriceps activation and median frequency (P < 0.001), but not to hamstring coactivation (P > 0.05). Discussion The results indicate that knee position significantly affects quadriceps force steadiness and activation strategies. This finding may have important implications for designing a force control testing protocol and interpreting test results. PMID:21404288

  5. Effects of kinesiology taping on repositioning error of the knee joint after quadriceps muscle fatigue.

    PubMed

    Han, Jin Tae; Lee, Jung-Hoon

    2014-06-01

    [Purpose] The purpose of this study was to identify the effects of kinesiology taping on repositioning error of the knee joint after quadriceps muscle fatigue. [Subjects] Thirty healthy adults with no orthopaedic or neurological problems participated in this study. [Methods] The repositioning error of the knee joint was measured using a digital goniometer when the subjects extended their dominant-side knee to a random target angle (30°, 45°, or 60°) with their eyes closed, before and after a quadriceps muscle fatigue protocol, and after application of kinesiology tape. [Results] We found that repositioning errors of the dominant-side knee joint increased after quadriceps fatigue compared with no-fatigue conditions. However, kinesiology taping of the quadriceps muscle and patella after quadriceps fatigue significantly decreased repositioning errors of the knee joint. [Conclusion] These results suggest that quadriceps fatigue increases the repositioning error of the knee joint, whereas application of kinesiology tape decreases fatigue-induced joint repositioning error.

  6. Influence of complete spinal cord injury on skeletal muscle within 6 mo of injury.

    PubMed

    Castro, M J; Apple, D F; Staron, R S; Campos, G E; Dudley, G A

    1999-01-01

    This study examined the influence of spinal cord injury (SCI) on affected skeletal muscle. The right vastus lateralis muscle was biopsied in 12 patients as soon as they were clinically stable (average 6 wk after SCI), and 11 and 24 wk after injury. Samples were also taken from nine able-bodied controls at two time points 18 wk apart. Surface electrical stimulation (ES) was applied to the left quadriceps femoris muscle to assess fatigue at these same time intervals. Biopsies were analyzed for fiber type percent and cross-sectional area (CSA), fiber type-specific succinic dehydrogenase (SDH) and alpha-glycerophosphate dehydrogenase (GPDH) activities, and myosin heavy chain percent. Controls showed no change in any variable over time. Patients showed 27-56% atrophy (P = 0.000) of type I, IIa, and IIax+IIx fibers from 6 to 24 wk after injury, resulting in fiber CSA approximately one-third that of controls. Their fiber type specific SDH and GPDH activities increased (P quadriceps femoris muscle showed moderately greater force loss during ES in patients than in controls. It is suggested that the predominant response of mixed human skeletal muscle within 6 mo of SCI is loss of contractile protein. Therapeutic interventions could take advantage of this to increase

  7. Complete paralysis of the quadriceps muscle caused by traumatic iliacus hematoma: a case report.

    PubMed

    Tamai, Kazuya; Kuramochi, Taro; Sakai, Hiroya; Iwami, Norio; Saotome, Koichi

    2002-01-01

    A15-year-old girl who developed traumatic iliacus hematoma and complete paralysis of the quadriceps muscle is reported. The current case and literature review revealed that incomplete quadriceps paralysis associated with traumatic iliacus hematoma is likely to progress to complete paralysis in days or weeks as a result of increased intracompartmental pressure. However, surgical decompression of the femoral nerve could produce good results even in patients who have complete quadriceps paralysis preoperatively.

  8. Matching initial torque with different stimulation parameters influences skeletal muscle fatigue.

    PubMed

    Bickel, C Scott; Gregory, Chris M; Azuero, Andres

    2012-01-01

    A fundamental barrier to using electrical stimulation in the clinical setting is an inability to maintain torque production secondary to muscle fatigue. Electrical stimulation parameters are manipulated to influence muscle torque production, and they may also influence fatigability during repetitive stimulation. Our purpose was to determine the response of the quadriceps femoris to three different fatigue protocols using the same initial torque obtained by altering stimulator parameter settings. Participants underwent fatigue protocols in which either pulse frequency (lowHz), pulse duration (lowPD), or voltage (lowV) was manipulated to obtain an initial torque that equaled 25% of maximum voluntary isometric contraction. Muscle soreness was reported on a visual analog scale 48 h after each fatigue test. The lowHz protocol resulted in the least fatigue (25% +/- 14%); the lowPD (50% +/- 13%) and lowV (48% +/- 14%) protocols had similar levels of fatigue. The lowHz protocol resulted in significantly less muscle soreness than the higher frequency protocols. Stimulation protocols that use a lower frequency coupled with long pulse durations and high voltages result in lesser amounts of muscle fatigue and perceived soreness. The identification of optimal stimulation patterns to maximize muscle performance will reduce the effect of muscle fatigue and potentially improve clinical efficacy.

  9. Quadriceps strength and weight acceptance strategies continue to improve two years after anterior cruciate ligament reconstruction

    PubMed Central

    Roewer, Ben D.; Di Stasi, Stephanie L.; Snyder-Mackler, Lynn

    2011-01-01

    The anterior cruciate ligament (ACL) is the most commonly-injured knee ligament during sporting activities. After injury, most individuals experience episodes of the knee giving way during daily activities (non-copers). Non-copers demonstrate asymmetrical quadriceps strength and movement patterns which could have long-term deleterious effects on the integrity of the knee joint. The purpose of this study was to determine if non-copers resolve their strength and movement asymmetries within two years after surgery. 26 non-copers were recruited to undergo pre-operative quadriceps strength testing and 3-dimensional gait analysis. Subjects underwent surgery to reconstruct the ligament followed by physical therapy focused on restoring normal range of motion, quadriceps strength, and function. Subjects returned for quadriceps strength testing and gait analysis six months and two years after surgery. Acutely after injury, quadriceps strength was asymmetric between limbs, but resolved six months after surgery. Asymmetric knee angles, knee moments, and knee and hip power profiles were also observed acutely after injury and persisted six months after surgery despite subjects achieving symmetrical quadriceps strength. Two years after surgery, quadriceps strength in the involved limb continued to improve and most kinematic and kinetic asymmetries resolved. These findings suggest that adequate quadriceps strength does not immediately resolve gait asymmetries in non-copers. They also suggest that non-copers have the capacity to improve their quadriceps strength and gait symmetry long after ACL reconstruction. PMID:21592482

  10. Effect of 3 Different Applications of Kinesio Taping Denko® on Electromyographic Activity: Inhibition or Facilitation of the Quadriceps of Males During Squat Exercise

    PubMed Central

    Serrão, Júlio C.; Mezêncio, Bruno; Claudino, João G.; Soncin, Rafael; Miyashiro, Pedro L. Sampaio; Sousa, Eric P.; Borges, Eduardo; Zanetti, Vinícius; Phillip, Igor; Mochizuki, Luiz; Amadio, Alberto C.

    2016-01-01

    Kinesio taping consists of a technique which uses the application of an elastic adhesive tape. It has become a widely used rehabilitation modality for the prevention and treatment of musculoskeletal disorders. The objective of this study was to verify the effect of the application of Kinesio Taping Denko® in three conditions (facilitation, inhibition, and placebo) on the electromyographic activity of the quadriceps and hamstrings muscles on facilitating or inhibiting the muscle function and on the perceived exertion during the barbell back squat exercise in healthy male subjects. Methods: It was a randomized, single-blinded and controlled study in which 18 males (28.0 ± 6.7 years old; 85.8 ± 8.2 kg mass; 1.80 ± 0.07 m tall; 0.97 ± 0.04 m lower limb length) performed barbell back squat exercise with different conditions of Kinesio Taping Denko® applications: Facilitation, inhibition and placebo. Previous to the mentioned conditions, all individuals were assessed without applying kinesio Taping Denko® during the exercise. OMNI scale was used after each set for perceived exertion evaluation. No differences (p < 0.05) in the electromyographic activity of the biceps femoris, vastus lateralis and vastus medialis or OMNI scale were recorded under any conditions. The results show that the kinesio taping denko®may not alter the magnitude of the electromyography activity of vastus lateralis, vastus medialis, and biceps femoris during the squat exercise. Furthermore, the perceived exertion was not affected by the kinesio taping denko® application. Key points Researchers involved in collecting data in this study have no financial or personal interest in the outcome of results or the sponsor. The perceived exertion was not affected by the kinesiology taping application. Kinesiology taping application may not alter the magnitude of EMG activity of vastuslateralis, vastusmedialis, and biceps femoris during the barbell back squat exercise. Electromyographic activity of

  11. Successful Treatment of Rectus Femoris Calcification with Ultrasound-guided Injection: A Case Report

    PubMed Central

    Hong, Myong Joo; Park, Jeong Ki; Kang, Tai Ug

    2015-01-01

    Painful periarticular calcification most commonly occurs within the rotator cuff of the shoulder and rarely around the elbow, hip, foot, and neck. As acute inflammatory reaction develops, severe pain, exquisite tenderness, local swelling, and limitation of motion with pain occur. In case of calcific tendinitis of the shoulder, it can be easily diagnosed according to the symptoms and with x-ray. However, in lesions of the hip, as it is a rare location and usually involves pain in the posterolateral aspect of the thigh, which can simulate radicular pain from a lumbar intervertebral disc, it could be difficult to diagnose. Hence, physicians usually focus on lumbar lesions; therefore, misdiagnosis is common and leads to a delayed management. Here, we report the case of a 30-year-old female patient with calcific tendinitis of the rectus femoris that was successfully managed with ultrasound-guided steroid injection. This study offers knowledge about the rectus femoris calcification. PMID:25589947

  12. Arthroscopic treatment of chronically painful calcific tendinitis of the rectus femoris

    PubMed Central

    2013-01-01

    Background Relatively large calcific tendinitis with persistent symptoms after extended periods of conservative treatment is an indication for operative therapy. Arthroscopy, as a treatment for calcific tendinitis of the hip abductors and calcinosis circumscripta, has been described previously; however, to our knowledge, the clinical and radiological response to arthroscopic removal of calcific tendinitis of the rectus femoris tendon has not. Methods We present arthroscopic treatment of unusual calcific tendonitis of the origin of the rectus femoris and associated intra-articular lesions in 3 patients with chronic coxa pain. Results Our cases show that hip arthroscopy is an effective therapeutic modality for calcific tendinitis of the hip joint with satisfactory short-term outcomes. Conclusions Calcific tendinitis, although an uncommon clinical entity, should be a part of the differential diagnosis of acute or chronic hip pain. PMID:24266900

  13. Calcific tendinitis of biceps femoris: an unusual site and cause for lateral knee pain.

    PubMed

    Chan, Warwick; Chase, Helen Emily; Cahir, John G; Walton, Neil Patrick

    2016-07-29

    A 37-year-old man presented to the acute knee and sports medicine clinic with atraumatic lateral knee pain. He had point tenderness over the lateral aspect of his knee which had not settled with anti-inflammatory medications. Imaging revealed a large opaque lesion lateral to the knee and although there was no clear mechanism, injury to the posterolateral corner was considered. An MRI subsequently revealed a rare case of calcific tendinitis to the biceps femoris tendon insertion. This condition was self-limiting and did not require interventions such as steroid injections. This is the first reported case of calcific tendinitis of biceps femoris as a cause of acute knee pain. 2016 BMJ Publishing Group Ltd.

  14. Arthroscopic treatment of chronically painful calcific tendinitis of the rectus femoris.

    PubMed

    Peng, Xu; Feng, Yong; Chen, Guangxing; Yang, Liu

    2013-11-23

    Relatively large calcific tendinitis with persistent symptoms after extended periods of conservative treatment is an indication for operative therapy. Arthroscopy, as a treatment for calcific tendinitis of the hip abductors and calcinosis circumscripta, has been described previously; however, to our knowledge, the clinical and radiological response to arthroscopic removal of calcific tendinitis of the rectus femoris tendon has not. We present arthroscopic treatment of unusual calcific tendonitis of the origin of the rectus femoris and associated intra-articular lesions in 3 patients with chronic coxa pain. Our cases show that hip arthroscopy is an effective therapeutic modality for calcific tendinitis of the hip joint with satisfactory short-term outcomes. Calcific tendinitis, although an uncommon clinical entity, should be a part of the differential diagnosis of acute or chronic hip pain.

  15. Treatment of Ischial Pressure Sores with Both Profunda Femoris Artery Perforator Flaps and Muscle Flaps

    PubMed Central

    Kim, Chae Min; Yun, In Sik; Lee, Dong Won; Lew, Dae Hyun; Rah, Dong Kyun

    2014-01-01

    Background Reconstruction of ischial pressure sore defects is challenging due to extensive bursas and high recurrence rates. In this study, we simultaneously applied a muscle flap that covered the exposed ischium and large bursa with sufficient muscular volume and a profunda femoris artery perforator fasciocutaneous flap for the management of ischial pressure sores. Methods We retrospectively analyzed data from 14 patients (16 ischial sores) whose ischial defects had been reconstructed using both a profunda femoris artery perforator flap and a muscle flap between January 2006 and February 2014. We compared patient characteristics, operative procedure, and clinical course. Results All flaps survived the entire follow-up period. Seven patients (50%) had a history of surgery at the site of the ischial pressure sore. The mean age of the patients included was 52.8 years (range, 18-85 years). The mean follow-up period was 27.9 months (range, 3-57 months). In two patients, a biceps femoris muscle flap was used, while a gracilis muscle flap was used in the remaining patients. In four cases (25%), wound dehiscence occurred, but healed without further complication after resuturing. Additionally, congestion occurred in one case (6%), but resolved with conservative treatment. Among 16 cases, there was only one (6%) recurrence at 34 months. Conclusions The combination of a profunda femoris artery perforator fasciocutaneous flap and muscle flap for the treatment of ischial pressure sores provided pliability, adequate bulkiness and few long-term complications. Therefore, this may be used as an alternative treatment method for ischial pressure sores. PMID:25075362

  16. Ruptured profunda femoris aneurysm secondary to neurofibromatosis: vascular involvement in an unusual location.

    PubMed

    Emrecan, Bilgin; Onem, Gokhan; Susam, Ibrahim

    2010-01-01

    Neurofibromatosis is an autosomal dominant genetic disease characterized by abnormal growth that involves tissues of mesodermal and neuroectodermal origin. Aneurysms are rarely seen in peripheral arteries. This report presents a case of ruptured arterial aneurysm secondary to neurofibromatosis; the lesion occurred in the profunda femoris artery, a highly unusual location. Treatment of patients with ruptured arterial aneurysm secondary to neurofibromatosis may be interventional or surgical. In this case, a surgical approach was successful.

  17. Heterogeneity of rectus femoris muscle architectural adaptations after two different 14-week resistance training programmes.

    PubMed

    Matta, Thiago T; Nascimento, Francisco X M B; Fernandes, Igor A; Oliveira, Liliam F

    2015-05-01

    This study aimed to determine the architectural changes of rectus femoris muscle at distinctive sites of the thigh length after two different 14-week resistance training programmes. Thirty-five untrained men were randomly allocated into three different groups: conventional resistance training (n = 12), isokinetic training (n = 12) and control (n = 11). Rectus femoris cross-sectional area, thickness and fascicle angle at two specific thigh sites (30% and 50% of the length) were assessed before and after 14 weeks of unilateral knee extension exercise or control. The isometric peak torque of the knee extensors was estimated as a muscle strength index. Conventional (30% = 47·4% versus 50% = 14·4%) and isokinetic (30% = 31·8% versus 50% = 11·4%) training induced significant increases on thickness at both rectus femoris sites. While conventional training resulted in substantial increments on cross-sectional area (30% = 62·1%, 50% = 19·5%), isokinetic training provoked a significant increase only at the distal site (50% = 64·7%). The isometric peak torque increased (22·4 and 29·6%, for conventional and isokinetic groups, respectively) after training independently of the training mode, although no significant changes were observed for any dependent variable in the control group. In general, the training modes resulted in similar changes on rectus femoris architecture, whereas their magnitude depended on the thigh site. © 2014 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  18. Impact of Pain Reported During Isometric Quadriceps Muscle Strength Testing in People With Knee Pain: Data From the Osteoarthritis Initiative

    PubMed Central

    Stratford, Paul W.

    2011-01-01

    Background Muscle force testing is one of the more common categories of diagnostic tests used in clinical practice. Clinicians have little evidence to guide interpretations of muscle force tests when pain is elicited during testing. Objective The purpose of this study was to examine the construct validity of isometric quadriceps muscle strength tests by determining whether the relationship between maximal isometric quadriceps muscle strength and functional status was influenced by pain during isometric testing. Design A cross-sectional design was used. Methods Data from the Osteoarthritis Initiative were used to identify 1,344 people with unilateral knee pain and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale scores of 1 or higher on the involved side. Measurements of maximal isometric quadriceps strength and ratings of pain during isometric testing were collected. Outcome variables were WOMAC physical function subscale, 20-m walk test, 400-m walk test, and a repeated chair stand test. Multiple regression models were used to determine whether pain during testing modified or confounded the relationship between strength and functional status. Results Pearson r correlations among the isometric quadriceps strength measures and the 4 outcome measures ranged from −.36 (95% confidence interval=−.41, −.31) for repeated chair stands to .36 (95% confidence interval=.31, .41) for the 20-m walk test. In the final analyses, neither effect modification nor confounding was found for the repeated chair stand test, the 20-m walk test, the 400-m walk test, or the WOMAC physical function subscale. Moderate or severe pain during testing was weakly associated with reduced strength, but mild pain was not. Limitations The disease spectrum was skewed toward mild or moderate symptoms, and the pain measurement scale used during muscle force testing was not ideal. Conclusions Given that the spectrum of the sample was skewed toward mild or moderate

  19. Proteome Changes in biceps femoris Muscle of Iranian
One-Humped Camel and Their Effect on Meat Quality Traits

    PubMed Central

    Varidi, Mohammad-Javad; Varidi, Mehdi

    2016-01-01

    Summary In this study physicochemical and quality traits of biceps femoris and longissimus thoracis muscles of male and female Iranian one-humped camel were determined during 14 days of refrigeration storage. Analysis of variance of the results showed that only shear force and temperature were affected by the gender (p<0.05). Anatomical location of the muscle influenced the meat properties except for drip loss (p<0.05). Also, except for cooking loss, ageing influenced the physicochemical and quality properties of meat; during 14 days of storage, proteolysis resulted in an increase of L* and b* values, drip loss and myofibrillar fragmentation index, and the decrease of a* value, expressed juice, shear force and sarcomere length. Proteome changes (myofibrillar proteins) during storage were investigated. Gel analysis revealed that 19 protein spots were significantly changed during 24, 72 and 168 h post-mortem. Fifteen spots were identified by MALDI-TOF/TOF mass spectrometer. Correlation analysis revealed significant correlations of actin, troponin T, capping protein, heat shock proteins (HSP) and desmin with physicochemical and quality properties of meat (p<0.05). Actin might be a potential protein marker for colour, tenderness and water-holding capacity, and HSP27 and desmin are good candidate markers for colour and tenderness, respectively. PMID:27956864

  20. Implementation of Open and Closed Kinetic Chain Quadriceps Strengthening Exercises after Anterior Cruciate Ligament Reconstruction.

    ERIC Educational Resources Information Center

    Ross, Michael D.; Denegar, Craig R.; Winzenried, Jay A.

    2001-01-01

    Reviews the effects of open kinetic chain (OKC) and closed kinetic chain (CKC) exercise on anterior cruciate ligament (ACL) strain and patellofemoral joint stress, suggesting a combination of the two for quadriceps strengthening after ACL reconstruction. Both OKC and CKC exercises may be modified and implemented for quadriceps strengthening after…

  1. Implementation of Open and Closed Kinetic Chain Quadriceps Strengthening Exercises after Anterior Cruciate Ligament Reconstruction.

    ERIC Educational Resources Information Center

    Ross, Michael D.; Denegar, Craig R.; Winzenried, Jay A.

    2001-01-01

    Reviews the effects of open kinetic chain (OKC) and closed kinetic chain (CKC) exercise on anterior cruciate ligament (ACL) strain and patellofemoral joint stress, suggesting a combination of the two for quadriceps strengthening after ACL reconstruction. Both OKC and CKC exercises may be modified and implemented for quadriceps strengthening after…

  2. Early versus late start of open kinetic chain quadriceps exercises after ACL reconstruction with patellar tendon or hamstring grafts: a prospective randomized outcome study.

    PubMed

    Heijne, Annette; Werner, Suzanne

    2007-04-01

    the 7 months follow-up compared with preoperative values were found. In conclusion, early start of OKC quadriceps exercises after hamstring ACL reconstruction resulted in significantly increased anterior knee laxity in comparison with both late start and with early and late start after bone-patellar tendon-bone ACL reconstruction. Furthermore, the early introduction of OKC exercises for quadriceps did not influence quadriceps muscle torques neither in patients operated on patellar tendon nor hamstring tendon grafts. On the contrary, it appears as if the choice of graft affected the strength of the specific muscle more than the type of exercises performed. Our results could not determine the appropriate time for starting OKC quadriceps exercises for patients who have undergone ACL reconstruction with hamstring tendon graft. Future studies of long-term results of anterior knee laxity and functional outcome are needed.

  3. Comparison of the hamstring/quadriceps ratio in females during squat exercise using various foot wedges.

    PubMed

    Yoo, Won-Gyu

    2016-08-01

    [Purpose] This study compared the hamstring/quadriceps ratio in females during squat exercise using various foot wedges. [Subjects and Methods] Nine females participated in this study. Surface electrodes measurements were taken over the hamstring and quadriceps under 3 squat exercise conditions, and the hamstring/quadriceps ratio was calculated. [Results] The hamstring/quadriceps ratio was significantly increased during squat exercise in inclined wedge condition (7.4 ± 1.8), compared to the declined wedge condition (5.3 ± 2.2) and no wedge condition (6.4 ± 3.2). [Conclusion] This study suggests that squat exercise in the inclined wedge condition may be effective for increasing the hamstring/quadriceps ratio in females.

  4. The correlation between muscle activity of the quadriceps and balance and gait in stroke patients

    PubMed Central

    Yang, Dae Jung; Park, Seung Kyu; Uhm, Yo Han; Park, Sam Heon; Chun, Dong Whan; Kim, Je Ho

    2016-01-01

    [Purpose] The purpose of this study was to examine the correlation between quadriceps muscle activity and balance and gait in stroke patients. [Subjects and Methods] Fifty-five stroke patients (30 males 25 females; mean age 58.7 years; stroke duration 4.82 months; Korean mini-mental state examination score 26.4) participated in this study. MP100 surface electromyography, BioRescue, and LUKOtronic were used to measure the quadriceps muscle activity, balance, and gait, respectively. [Results] There was a significant correlation between quadriceps muscle activity (vastus lateralis % reference voluntary contraction, vastus medialis % reference voluntary contraction) and balance (limits of stability) and gait (gait velocity) but there was none between vastus lateralis % reference voluntary contraction, vastus medialis % reference voluntary contraction. [Conclusion] An increase in quadriceps muscle activity will improve balance and gait ability. To improve function in stroke patients, training is needed to strengthen the quadriceps muscles. PMID:27630416

  5. Can an anterior quadriceps release improve range of motion in the stiff arthritic knee?

    PubMed

    Tarabichi, Samih; Tarabichi, Yasir

    2010-06-01

    We hypothesize that tethering adhesions of the quadriceps muscle are the major pathological structures responsible for a limited range of motion in the stiff arthritic knee. Forty-two modified quadriceps muscle releases were performed on 24 patients with advanced osteoarthritis scheduled for total knee arthroplasty. The ranges of motion were documented intraoperatively both before and immediately after the release. Passive flexion improved significantly in all patients (mean, 32.4 degrees of improvement, P < .001) following a modified quadriceps release, despite any presence of osteophytes or severe deformities. These results strongly implicate adhesions of the quadriceps muscle to the underlying femur, which prevent the distal excursion of the quadriceps tendon, as the restrictive pathology preventing deep flexion in patients with osteoarthritis.

  6. Comparison of the hamstring/quadriceps ratio in females during squat exercise using various foot wedges

    PubMed Central

    Yoo, Won-gyu

    2016-01-01

    [Purpose] This study compared the hamstring/quadriceps ratio in females during squat exercise using various foot wedges. [Subjects and Methods] Nine females participated in this study. Surface electrodes measurements were taken over the hamstring and quadriceps under 3 squat exercise conditions, and the hamstring/quadriceps ratio was calculated. [Results] The hamstring/quadriceps ratio was significantly increased during squat exercise in inclined wedge condition (7.4 ± 1.8), compared to the declined wedge condition (5.3 ± 2.2) and no wedge condition (6.4 ± 3.2). [Conclusion] This study suggests that squat exercise in the inclined wedge condition may be effective for increasing the hamstring/quadriceps ratio in females. PMID:27630437

  7. Sagittal patellar tilt and concomitant quadriceps hypotrophy after tibial nailing.

    PubMed

    Aksahin, Ertugrul; Yilmaz, Serdar; Karasoy, Ismail; Duran, Semra; Yuksel, H Yalcin; Dogan, Ozgur; Yildirim, A Ozgur; Bicimoglu, Ali

    2016-09-01

    The aim of the study was to analyse the patellofemoral alignment in the sagittal plane following tibial fracture surgery with intramedullary nailing and its relationship to parapatellar muscle status. The patellofemoral MRI results of 27 patients (15 males and 12 females) treated with locked intramedullary nailing following tibia shaft fracture were reviewed. The mean age of the patients was 41.8 (±15) years. The patella-patellar tendon angle (P-PT) and the distance between the inferior patellar pole and the tibial tubercle (DP-TT) were evaluated for both the operated extremity and the contralateral normal side. MRI assessment of the infrapatellar fat pad, quadriceps, sartorius, gracilis, semi-membranosus muscles and biceps muscles was also carried out. The correlation between the changes in skeletal muscle mass, the volume of the infrapatellar fat pad and the alterations in the DP-TT distances and P-PT angles were analysed. The quadriceps muscle cross-sectional diameter had a mean of 157.2 mm(2) (115.6/319.5) in the operated extremity, and it was 193 mm(2) (77.6/282.2) in the non-operated normal side (p = 0.001). For the Gracilis muscle, the mean was 84.4 mm(2) (19.7/171) at the operated extremity and 75.7 mm(2) (26.9/238.2) on the normal side (p = 0.05). The cross-sectional areas of the semi-membranosus, sartorius and biceps muscles in the operated and non-operated extremity were not noticeably different (n.s). The P-PT angle was 153° (129.7/156.4) in the operated extremity and 145.7° (137.6/163.4) in the non-operated normal extremity (p < 0.05). While DP-TT distance was 11.4 mm (9.4/20.4) in the operated extremity, it was 14.1 mm (7.3/17.1) in the non-operated extremity (p = 0.001). The correlation analyses revealed that the quadriceps hypotrophy negatively correlated (r = -0.4, p = 0.02) with the P-PT angle but positively correlated with the increase in gracilis muscle volume (r = 0.4, p = 0.03). This study revealed that patellofemoral

  8. Impaired voluntary quadriceps force control following anterior cruciate ligament reconstruction: relationship with knee function.

    PubMed

    Perraton, Luke; Clark, Ross; Crossley, Kay; Pua, Yong-Hao; Whitehead, Tim; Morris, Hayden; Telianidis, Stacey; Bryant, Adam

    2017-05-01

    Impairments in quadriceps force control and altered quadriceps and hamstring muscle activation strategies have been observed following anterior cruciate ligament reconstruction; however, the functional implications of these impairments are unclear. This study examined the cross-sectional associations between quadriceps force control, quadriceps activation, hamstring coactivation and clinically assessed knee function following anterior cruciate ligament reconstruction with a hamstring graft. Sixty-six patients (18 ± 3 months following surgery) and 41 uninjured individuals participated. Quadriceps force control was assessed using an isometric knee extension task. Participants cyclically increased and decreased quadriceps force at slow speeds between 5 and 30 % maximum voluntary isometric contraction matching a moving target displayed on a screen. Quadriceps activation and hamstring coactivation were assessed concurrently using surface electromyography. Knee function was assessed with the Cincinnati Knee Rating Scale and three single-leg hop tests. The reconstructed group completed the task with 48 % greater root-mean-square error (RMSE), indicating significantly worse quadriceps force control (p < 0.001). In a multivariable model adjusted for sex, greater RMSE and greater lateral hamstring coactivation were significantly associated with worse knee function that is greater odds of scoring <85 % on one or more knee functional assessment. Less-accurate quadriceps force output and greater hamstring coactivation are associated with worse knee joint function following anterior cruciate ligament reconstruction and may contribute to irregular knee joint loading and the onset or progression of knee osteoarthritis. Impairments in quadriceps force control and altered muscle activation strategies may be modifiable through neuromuscular training, and this is an area for future research. Case-control study, Level III.

  9. Use of Ultrasound to Monitor Biceps Femoris Mechanical Adaptations after Injury in a Professional Soccer Player

    PubMed Central

    Kellis, Eleftherios; Galanis, Nikiforos; Chrysanthou, Chrysanthos; Kofotolis, Nikolaos

    2016-01-01

    This study examined the use of ultrasound to monitor changes in the long head of the biceps femoris (BF) architecture of aprofessional soccer player with acute first-time hamstring strain. The player followed a 14 session physiotherapy treatment until return to sport. The pennation angle and aponeurosis strain of the long head of the biceps femoris (BF) were monitored at 6 occasions (up until 1 year) after injury. The size of the scar / hematoma was reduced by 63.56% (length) and 67.9% (width) after the intervention and it was almost non-traceable one year after injury. The pennation angle of the fascicles underneath the scar showed a decline of 51.4% at the end of the intervention while an increase of 109.2% of the fascicles which were closer to deep aponeurosis was observed. In contrast, pennation angle of fascicles located away from the injury site were relatively unaffected. The treatment intervention resulted in a 57.9% to 77.3% decline of maximum strain per unit of MVC moment and remained similar one year after the intervention. This study provided an example of the potential use of ultrasound-based parameters to link the mechanical adaptations of the injured muscle to specific therapeutic intervention. Key points Changes in fascicle orientation after biceps femoris mild tear were reduced after a 28 day intervention and remained similar one year after injury. Tendon/aponeurosis strain per unit of moment of force decreased during the course of the therapeutic intervention. Future studies could utilize ultrasonography to monitor mechanical responses after various types of hamstring injury and interventions in order to improve criteria for a safe return to sport. PMID:26957929

  10. Use of Ultrasound to Monitor Biceps Femoris Mechanical Adaptations after Injury in a Professional Soccer Player.

    PubMed

    Kellis, Eleftherios; Galanis, Nikiforos; Chrysanthou, Chrysanthos; Kofotolis, Nikolaos

    2016-03-01

    This study examined the use of ultrasound to monitor changes in the long head of the biceps femoris (BF) architecture of aprofessional soccer player with acute first-time hamstring strain. The player followed a 14 session physiotherapy treatment until return to sport. The pennation angle and aponeurosis strain of the long head of the biceps femoris (BF) were monitored at 6 occasions (up until 1 year) after injury. The size of the scar / hematoma was reduced by 63.56% (length) and 67.9% (width) after the intervention and it was almost non-traceable one year after injury. The pennation angle of the fascicles underneath the scar showed a decline of 51.4% at the end of the intervention while an increase of 109.2% of the fascicles which were closer to deep aponeurosis was observed. In contrast, pennation angle of fascicles located away from the injury site were relatively unaffected. The treatment intervention resulted in a 57.9% to 77.3% decline of maximum strain per unit of MVC moment and remained similar one year after the intervention. This study provided an example of the potential use of ultrasound-based parameters to link the mechanical adaptations of the injured muscle to specific therapeutic intervention. Key pointsChanges in fascicle orientation after biceps femoris mild tear were reduced after a 28 day intervention and remained similar one year after injury.Tendon/aponeurosis strain per unit of moment of force decreased during the course of the therapeutic intervention.Future studies could utilize ultrasonography to monitor mechanical responses after various types of hamstring injury and interventions in order to improve criteria for a safe return to sport.

  11. Effect of dry needling on myofascial pain syndrome of the quadratus femoris: A case report.

    PubMed

    Anandkumar, Sudarshan

    2017-09-18

    This case report describes a 40-year-old male who presented with posterior thigh pain managed unsuccessfully with massage therapy, chiropractic adjustments, and physical therapy. The diagnosis of myofascial pain syndrome (MPS) involving the quadratus femoris (QF) was purely clinical, based on palpatory findings and ruling out other conditions through deductive reasoning. This is potentially a first time report, describing the successful management of MPS of the QF with dry needling (DN) using a recently published DN grading system. Immediate improvements were noted in all the outcome measures after the first treatment, with complete pain-resolution maintained at a 4-month follow-up.

  12. A new isometric quadriceps-strengthening exercise using EMG-biofeedback

    PubMed Central

    Kesemenli, Cumhur C; Sarman, Hakan; Baran, Tuncay; Memisoglu, Kaya; Binbir, Ismail; Savas, Yilmaz; Isik, Cengiz; Boyraz, Ismail; Koc, Bunyamin

    2014-01-01

    A new isometric contraction quadriceps-strengthening exercise was developed to restore the quadriceps strength lost after knee surgery more rapidly. This study evaluated the results of this new method. Patients were taught to perform the isometric quadriceps-strengthening exercise in the unaffected knee in the supine position, and then they performed it in the affected knee. First, patients were taught the classical isometric quadriceps-strengthening exercise, and then they were taught our new alternative method: “pull the patella superiorly tightly and hold the leg in the same position for 10 seconds”. Afterward, the quadriceps contraction was evaluated using a non-invasive Myomed 932 EMG-biofeedback device (Enraf-Nonius, The Netherlands) with gel-containing 48 mm electrodes (Türklab, The Turkey) placed on both knees. The isometric quadriceps-strengthening exercise performed using our new method had stronger contraction than the classical method (P < 0.01). The new method involving pulling the patella superiorly appears to be a better choice, which can be applied easily, leading to better patient compliance and greater quadriceps force after arthroscopic and other knee surgeries. PMID:25356122

  13. Preferential reduction of quadriceps over respiratory muscle strength and bulk after lung transplantation for cystic fibrosis

    PubMed Central

    Pinet, C; Scillia, P; Cassart, M; Lamotte, M; Knoop, C; Melot, C; Estenne, M

    2004-01-01

    Background: In the absence of complications, recipients of lung transplants for cystic fibrosis have normal pulmonary function but the impact of the procedure on the strength and bulk of respiratory and limb muscles has not been studied. Methods: Twelve stable patients who had undergone lung transplantation for cystic fibrosis 48 months earlier (range 8–95) and 12 normal subjects matched for age, height, and sex were studied. The following parameters were measured: standard lung function, peak oxygen uptake by cycle ergometry, diaphragm surface area by computed tomographic (CT) scanning, diaphragm and abdominal muscle thickness by ultrasonography, twitch transdiaphragmatic and gastric pressures, quadriceps isokinetic strength, and quadriceps cross section by CT scanning, and lean body mass. Diaphragm mass was computed from diaphragm surface area and thickness. Results: Twitch transdiaphragmatic and gastric pressures, diaphragm mass, and abdominal muscle thickness were similar in the two groups but quadriceps strength and cross section were decreased by nearly 30% in the patients. Patients had preserved quadriceps strength per unit cross section but reduced quadriceps cross section per unit lean body mass. The cumulative dose of corticosteroids was an independent predictor of quadriceps atrophy. Peak oxygen uptake showed positive correlations with quadriceps strength and cross section in the two groups, but peak oxygen uptake per unit quadriceps strength or cross section was reduced in the patient group. Conclusions: The diaphragm and abdominal muscles have preserved strength and bulk in patients transplanted for cystic fibrosis but the quadriceps is weak due to muscle atrophy. This atrophy is caused in part by corticosteroid therapy and correlates with the reduction in exercise capacity. PMID:15333856

  14. Quadriceps Inhibition After Repetitive Lumbar Extension Exercise in Persons With a History of Low Back Pain

    PubMed Central

    Hart, Joseph M; Fritz, Julie M; Kerrigan, D. Casey; Saliba, Ethan N; Gansneder, Bruce M; Ingersoll, Christopher D

    2006-01-01

    Context: A neuromuscular relationship exists between the lumbar extensor and quadriceps muscles during fatiguing exercise. However, this relationship may be different for persons with low back pain (LBP). Objective: To compare quadriceps inhibition after isometric, fatiguing lumbar extension exercise between persons with a history of LBP and control subjects. Design: A 2 × 3 factorial, repeated-measures, time-series design with independent variables of group (persons with a history of LBP, controls) and time (baseline, postexercise set 1, postexercise set 2). Setting: University research laboratory. Patients or Other Participants: Twenty-five subjects with a history of LBP were matched by sex, height, and mass to 25 healthy control subjects. Intervention(s): Electromyography median frequency indexed lumbar paraspinal muscular fatigue while subjects performed 2 sets of isometric lumbar extension exercise. Subjects exercised until a 15% downward shift in median frequency for the first set and a 25% shift for the second set were demonstrated. Main Outcome Measure(s): Knee extension force was measured while subjects performed an isometric maximal quadriceps contraction. During this maximal effort, a percutaneous electric stimulus was applied to the quadriceps, causing a transient, supramaximal increase in force output. We used the ratio between the 2 forces to estimate quadriceps inhibition. Quadriceps electromyographic activity was recorded during the maximal contractions to compare median frequencies over time. Results: Both groups exhibited significantly increased quadriceps inhibition after the first (12.6% ± 10.0%, P < .001) and second (15.2% ± 9.7%, P < .001) exercise sets compared with baseline (9.6% ± 9.3%). However, quadriceps inhibition was not different between groups. Conclusions: Persons with a history of LBP do not appear to be any more or less vulnerable to quadriceps inhibition after fatiguing lumbar extension exercise. PMID:17043693

  15. Phototherapy during treadmill training improves quadriceps performance in postmenopausal women.

    PubMed

    Paolillo, F R; Corazza, A V; Paolillo, A R; Borghi-Silva, A; Arena, R; Kurachi, C; Bagnato, V S

    2014-06-01

    To evaluate the effects of infrared-light-emitting diode (LED) during treadmill training on functional performance. Thirty postmenopausal women aged 50-60 years were randomly assigned to one of three groups and successfully completed the full study. The three groups were: (1) the LED group, which performed treadmill training associated with phototherapy (n = 10); (2) the exercise group, which carried out treadmill training only (n = 10); and (3) the sedentary group, which neither performed physical training nor underwent phototherapy (n = 10). Training was performed over a period of 6 months, twice a week for 45 min per session at 85-90% of maximal heart rate, which was obtained during progressive exercise testing. The irradiation parameters were 100 mW, 39 mW/cm(2) and 108 J/cm(2) for 45 min. Quadriceps performance was measured during isokinetic exercise testing at 60°/s and 300°/s. Peak torque did not differ amongst the groups. However, the results showed significantly higher values of power and total work for the LED group (∆ = 21 ± 6 W and ∆ = 634 ± 156 J, p < 0.05) when compared to both the exercise group (∆ = 13 ± 10 W and = 410 ± 270 J) and the sedentary group (∆ = 10 ± 9 W and ∆ = 357 ± 327 J). Fatigue was also significantly lower in the LED group (∆ = -7 ± 4%, p < 0.05) compared to both the exercise group (∆ = 3 ± 8%) and the sedentary group (∆ = -2 ± 6%). Infrared-LED during treadmill training may improve quadriceps power and reduce peripheral fatigue in postmenopausal women.

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

    PubMed Central

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

    2016-01-01

    postrehabilitation, the peak knee flexion angle was positively associated with peak torque and RTD0-200ms, and the knee extension moment was positively associated with RTD0-200ms. At 1 year postsurgery, peak knee flexion angle and knee extension moment were both positively associated with peak torque, RTD0-200ms, and RTD0–peak torque. Conclusion: Although the hop symmetry index could be considered satisfactory for returning to sports, asymmetries in landing mechanics still exist in the first year postmeniscectomy. Greater quadriceps strength was associated with greater single-leg hop distance and better landing mechanics at both postrehabilitation and 1 year postsurgery. Knee activity self-efficacy was the only psychosocial factor associated with single-leg hop performance and isolated to a positive association with single-leg hop distance at postrehabilitation. Clinical Relevance: Rate of development is not typically measured in the clinic but can be an additional quadriceps measure to monitor for single-leg hop performance. Quadriceps strength and psychosocial factors appear to have separate influence on single-leg hop performance after meniscectomy, which has implications for developing appropriate interventions for optimal single-leg hop performance. PMID:28210647

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

    PubMed

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

    2016-12-01

    associated with peak torque and RTD0-200ms, and the knee extension moment was positively associated with RTD0-200ms. At 1 year postsurgery, peak knee flexion angle and knee extension moment were both positively associated with peak torque, RTD0-200ms, and RTD0-peak torque. Although the hop symmetry index could be considered satisfactory for returning to sports, asymmetries in landing mechanics still exist in the first year postmeniscectomy. Greater quadriceps strength was associated with greater single-leg hop distance and better landing mechanics at both postrehabilitation and 1 year postsurgery. Knee activity self-efficacy was the only psychosocial factor associated with single-leg hop performance and isolated to a positive association with single-leg hop distance at postrehabilitation. Rate of development is not typically measured in the clinic but can be an additional quadriceps measure to monitor for single-leg hop performance. Quadriceps strength and psychosocial factors appear to have separate influence on single-leg hop performance after meniscectomy, which has implications for developing appropriate interventions for optimal single-leg hop performance.

  18. Biomechanical Evaluation of Posterior Cruciate Ligament Reconstruction With Quadriceps Versus Achilles Tendon Bone Block Allograft

    PubMed Central

    Forsythe, Brian; Haro, Marc S.; Bogunovic, Ljiljana; Collins, Michael J.; Arns, Thomas A.; Trella, Katie J.; Shewman, Elizabeth F.; Verma, Nikhil N.; Bach, Bernard R.

    2016-01-01

    Background: Long-term studies of posterior cruciate ligament (PCL) reconstruction suggest that normal stability is not restored in the majority of patients. The Achilles tendon allograft is frequently utilized, although recently, the quadriceps tendon has been introduced as an alternative option due to its size and high patellar bone density. Purpose/Hypothesis: The purpose of this study was to compare the biomechanical strength of PCL reconstructions using a quadriceps versus an Achilles allograft. The hypothesis was that quadriceps bone block allograft has comparable mechanical properties to those of Achilles bone block allograft. Study Design: Controlled laboratory study. Methods: Twenty-nine fresh-frozen cadaveric knees were assigned to 1 of 3 groups: (1) intact PCL, (2) PCL reconstruction with Achilles tendon allograft, or (3) PCL reconstruction with quadriceps tendon allograft. After reconstruction, all supporting capsular and ligamentous tissues were removed. Posterior tibial translation was measured at neutral and 20° external rotation. Each specimen underwent a preload, 2 cyclic loading protocols of 500 cycles, then load to failure. Results: Construct creep deformation was significantly lower in the intact group compared with both Achilles and quadriceps allograft (P = .008). The intact specimens reached the greatest ultimate load compared with both reconstructions (1974 ± 752 N, P = .0001). The difference in ultimate load for quadriceps versus Achilles allograft was significant (P = .048), with the quadriceps group having greater maximum force during failure testing. No significant differences were noted between quadriceps versus Achilles allograft for differences in crosshead excursion during cyclic testing (peak-valley [P-V] extension stretch), creep deformation, or stiffness. Construct stiffness measured during the failure test was greatest in the intact group (117 ± 9 N/mm, P = .0001) compared with the Achilles (43 ± 11 N/mm) and quadriceps (43

  19. Persistent Neuromuscular and Corticomotor Quadriceps Asymmetry After Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Kuenze, Christopher M.; Hertel, Jay; Weltman, Arthur; Diduch, David; Saliba, Susan A.; Hart, Joseph M.

    2015-01-01

    Context: Return to activity in the presence of quadriceps dysfunction may predispose individuals with anterior cruciate ligament reconstruction (ACLR) to long-term joint degeneration. Asymmetry may manifest during movement and result in altered knee-joint–loading patterns; however, the underlying neurophysiologic mechanisms remain unclear. Objective: To compare limb symmetry of quadriceps neuromuscular function between participants with ACLR and participants serving as healthy controls. Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: A total of 22 individuals with ACLR (12 men, 10 women) and 24 individuals serving as healthy controls (12 men, 12 women). Main Outcome Measure(s): Normalized knee-extension maximal voluntary isometric contraction (MVIC) torque (Nm/kg), quadriceps central activation ratio (CAR) (%), quadriceps motor-neuron–pool excitability (Hoffmann reflex to motor wave ratio), and quadriceps active motor threshold (AMT) (% 2.0 T) were measured bilaterally and used to calculate limb symmetry indices for comparison between groups. We used analyses of variance to compare quadriceps Hoffmann reflex to motor wave ratio, normalized knee-extension MVIC torque, quadriceps CAR, and quadriceps AMT between groups and limbs. Results: The ACLR group exhibited greater asymmetry in knee-extension MVIC torque (ACLR group = 0.85 ± 0.21, healthy group = 0.97 ± 0.14; t44 = 2.26, P = .03), quadriceps CAR (ACLR group = 0.94 ± 0.11, healthy group = 1.00 ± 0.08; t44 = 2.22, P = .04), and quadriceps AMT (ACLR group = 1.13 ± 0.18, healthy group = 1.02 ± 0.11; t34 = −2.46, P = .04) than the healthy control group. Conclusions: Asymmetries in measures of quadriceps function and cortical excitability were present in patients with ACLR. Asymmetry in quadriceps strength, activation, and cortical excitability persisted in individuals with ACLR beyond return to recreational activity. Measuring the magnitude of asymmetry

  20. The force-length curves of the human rectus femoris and gastrocnemius muscles in vivo.

    PubMed

    Winter, Samantha L; Challis, John H

    2010-02-01

    For a physiologically realistic joint range of motion and therefore range of muscle fiber lengths, only part of the whole muscle force-length curve can be used in vivo; that is, only a section of the force-length curve is expressed. Previous work has determined that the expressed section of the force-length curve for individual muscles can vary between subjects; however, the degree of intersubject variability is different for different muscles. This study determined the expressed section of both the rectus femoris and gastrocnemius--muscles with very different ratios of tendon slack length to muscle fiber optimum length--for 28 nonspecifically trained subjects to test the hypothesis that the value of this ratio affects the amount of variability in the expressed section. The force-length curves of the two muscles were reconstructed from moment-angle data using the method of Herzog & ter Keurs (1988). There was no relationship between the expressed sections of the force-length curve for the two muscles. Less variability was found in the expressed section of the gastrocnemius compared with the rectus femoris, supporting the hypothesis. The lack of relationship between the expressed sections of the two muscles has implications for motor control and for training muscle for rehabilitation.

  1. Effects of eccentric strength training on biceps femoris muscle architecture and knee joint range of movement.

    PubMed

    Potier, Tara G; Alexander, Caroline M; Seynnes, Olivier R

    2009-04-01

    The aim was to determine whether eccentric strengthening changed the muscle architecture of human biceps femoris and consequently, knee range of motion. Twenty-two subjects were randomly assigned to control and experimental groups. The experimental group completed an eccentric strengthening programme for 8 weeks. Outcome measures included hamstring muscle strength (one repetition maximum), the passive knee extension test (PKE) (knee joint angle at which the onset of passive tension occurs), fascicle length (FL) and pennation angle (PA). One repetition maximum increased by 34% (P < 0.01), the PKE test revealed a 5% increase in joint range of motion (P = 0.01), FL increased by 34% (P = 0.01) and PA did not change (P = 0.38). This is the first report of an increase in FL in the biceps femoris following eccentric resistance training. In addition, the results might imply that this fascicle lengthening could lead to an increase in the range of motion of the knee. Clinical implications for rehabilitation and injury prevention are discussed.

  2. Rectus Femoris Echo Intensity Correlates with Muscle Strength, but Not Endurance, in Younger and Older Men.

    PubMed

    Mota, Jacob A; Stock, Matt S

    2017-08-01

    We examined correlations between echo intensity and muscle strength and endurance. Rectus femoris echo intensity, maximal voluntary contraction (MVC) force and time to task failure during a 50% MVC task were determined for 12 younger (mean age = 25 y) and 13 older (mean age = 74 y) men. Bivariate correlations between echo intensity and normalized MVC force were similar for younger and older men, but was only statistically significant for the latter (younger r = -0.559, p = 0.059; older r = -0.580, p = 0.038). When all patients were combined, the correlation was significant (r = -0.733, p < 0.001). Significant correlations were not observed for time to task failure (younger r = -0.382, p = 0.221; older r = -0.347, p = 0.246; all patients r = -0.229, p = 0.270). Rectus femoris echo intensity is associated with muscle strength, but not endurance, in younger and older men. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  3. Quadriceps Strength, Muscle Activation Failure, and Patient-Reported Function at the Time of Return to Activity in Patients Following Anterior Cruciate Ligament Reconstruction: A Cross-sectional Study

    PubMed Central

    Lepley, Lindsey K.; Palmieri-Smith, Riann M.

    2016-01-01

    Study Design Cross-sectional. Objectives To determine if quadriceps activation failure (QAF) moderates the relationship between quadriceps strength and physical function in individuals post-anterior cruciate ligament (ACL) reconstruction. Background QAF may impair the recovery of physical function post ACL reconstruction, given that QAF reduces strength, and strength is related to physical function. Evidence of this relationship has been found in individuals with knee osteoarthritis, wherein patients with lower strength and greater QAF had lower levels of physical function. Methods Participants consisted of 52 individuals who were cleared for return to activity at an average ± SD of 7.4 ± 1.2 months post ACL reconstruction. QAF was assessed using the superimposed burst technique and quadriceps strength was assessed using concentric isokinetic contractions (Nm/kg). Physical function was quantified using a combined variable of physical (single leg hop for distance) and self-reported function (International Knee Documentation Committee form) calculated using a principal component analysis (PCPF). Simple correlations were then performed to determine the order in which variables were entered into the regression model to evaluate if QAF moderates the relationship between quadriceps strength and physical function. Results The combination of quadriceps strength and the interaction of strength-by-QAF predicted 30% of the variance in physical function (R2=0.30, P<.001; PCPF = -0.61strength + 0.20interaction - 1.896); however the interaction of strength-by-QAF only accounted for 7% of the capabilities of the model (P=.023). Conclusion Physical function is largely influenced by the recovery of quadriceps strength and minimally attenuated by QAF. These data suggest that QAF may affect individuals post ACL reconstruction differently, and to a lesser extent, than knee individuals with knee osteoarthritis. PMID:26471854

  4. Preferential Quadriceps Activation in Female Athletes With Incremental Increases in Landing Intensity

    PubMed Central

    Ford, Kevin R.; Myer, Gregory D.; Schmitt, Laura C.; Uhl, Timothy L.; Hewett, Timothy E.

    2014-01-01

    The purpose of this study was to identify alterations in preparatory muscle activation patterns across different drop heights in female athletes. Sixteen female high school volleyball players performed the drop vertical jump from three different drop heights. Surface electromyography of the quadriceps and hamstrings were collected during the movement trials. As the drop height increased, muscle activation of the quadriceps during preparatory phase also increased (p < .05). However, the hamstrings activation showed no similar increases relative to drop height. Female athletes appear to preferentially rely on increased quadriceps activation, without an increase in hamstrings activation, with increased plyometric intensity. The resultant decreased activation ratio of the hamstrings relative to quadriceps before landing may represent altered dynamic knee stability and may contribute to the increased risk of ACL injury in female athletes. PMID:21844610

  5. Percutaneous quadriceps tendon pie-crusting release of extension contracture of the knee.

    PubMed

    Liu, H X; Wen, H; Hu, Y Z; Yu, H C; Pan, X Y

    2014-05-01

    To release extension contracture of the knee, the authors used a minimally invasive technique: percutaneous quadriceps tendon pie-crusting release. Percutaneous pie-crusting release was performed using an 18-gauge needle to puncture the stiff fibrous band of the distal and lateral quadriceps tendon under maximum knee flexion. Quadriceps contracture was gradually released by multiple needle punctures. A knee brace was prescribed for one week and knee flexion exercises were performed on the first postoperative day. This technique was performed in seven post-traumatic stiff knees and five stiff total knee arthroplasties. Mean maximum flexion increased from 37° preoperatively to 50° after arthrolysis and 107(o) after pie-crusting. At a mean follow-up of eight months, mean maximum flexion was 103°. There were no major complications. The technique of quadriceps tendon pie-crusting release is a simple, minimally invasive and effective treatment for knee extension contracture.

  6. 'MYNI's orthosis': a self-adjustable, dynamic knee extension orthosis for quadriceps weakness in haemophilia rehabilitation.

    PubMed

    Manigandan, C; Bedford, E; Kumar, S; Nathan, V; Peter, B K; Premkumar, J Charles

    2004-11-01

    In developing countries like India, where walking is the primary, preferred and feasible mode of transport, the implications following quadriceps weakness poses a serious threat to ones functional independence. This has been a challenge for professionals while ambulating individuals with haemophilia, where quadriceps weakness is very common. Although external splinting has been understood for many years, as a means of support in haemophilia, there is still a dearth of knowledge in making an appropriate splint to assist or to take over the weak quadriceps during ambulation. This newly designed 'MYNI's orthosis' helps in versatile ways in addition to assisting the weak quadriceps. It provides prolonged stretch to contracted tissue, allows for being used as a serial cast in improving the knee range and is cosmetically acceptable. Above all, it is user-friendly, thus enhancing compliance and superior outcome in haemophilic knee rehabilitation.

  7. Quadriceps arthrogenic muscle inhibition: the effects of experimental knee joint effusion on motor cortex excitability.

    PubMed

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

    2014-12-10

    Marked weakness of the quadriceps muscles is typically observed following injury, surgery or pathology affecting the knee joint. This is partly due to ongoing neural inhibition that prevents the central nervous system from fully activating the quadriceps, a process known as arthrogenic muscle inhibition (AMI). This study aimed to further investigate the mechanisms underlying AMI by exploring the effects of experimental knee joint effusion on quadriceps corticomotor and intracortical excitability. Seventeen healthy volunteers participated in this study. Transcranial magnetic stimulation was used to measure quadriceps motor evoked potential area, short-interval intracortical inhibition, intracortical facilitation and cortical silent period duration before and after experimental knee joint effusion. Joint effusion was induced by the intraarticular infusion of dextrose saline into the knee. There was a significant increase in quadriceps motor evoked potential area following joint infusion, both at rest (P = 0.01) and during voluntary muscle contraction (P = 0.02). Cortical silent period duration was significantly reduced following joint infusion (P = 0.02). There were no changes in short interval intracortical inhibition or intracortical facilitation over time (all P > 0.05). The results of this study provide no evidence for a supraspinal contribution to quadriceps AMI. Paradoxically, but consistent with previous observations in patients with chronic knee joint pathology, quadriceps corticomotor excitability increased after experimental knee joint effusion. The increase in quadriceps corticomotor excitability may be at least partly mediated by a decrease in gamma-aminobutyric acid (GABA)-ergic inhibition within the motor cortex.

  8. Quadriceps tendon allografts as an alternative to Achilles tendon allografts: a biomechanical comparison.

    PubMed

    Mabe, Isaac; Hunter, Shawn

    2014-12-01

    Quadriceps tendon with a patellar bone block may be a viable alternative to Achilles tendon for anterior cruciate ligament reconstruction (ACL-R) if it is, at a minimum, a biomechanically equivalent graft. The objective of this study was to directly compare the biomechanical properties of quadriceps tendon and Achilles tendon allografts. Quadriceps and Achilles tendon pairs from nine research-consented donors were tested. All specimens were processed to reduce bioburden and terminally sterilized by gamma irradiation. Specimens were subjected to a three phase uniaxial tension test performed in a custom environmental chamber to maintain the specimens at a physiologic temperature (37 ± 2 °C) and misted with a 0.9 % NaCl solution. There were no statistical differences in seven of eight structural and mechanical between the two tendon types. Quadriceps tendons exhibited a significantly higher displacement at maximum load and significantly lower stiffness than Achilles tendons. The results of this study indicated a biomechanical equivalence of aseptically processed, terminally sterilized quadriceps tendon grafts with bone block to Achilles tendon grafts with bone block. The significantly higher displacement at maximum load, and lower stiffness observed for quadriceps tendons may be related to the failure mode. Achilles tendons had a higher bone avulsion rate than quadriceps tendons (86 % compared to 12 %, respectively). This was likely due to observed differences in bone block density between the two tendon types. This research supports the use of quadriceps tendon allografts in lieu of Achilles tendon allografts for ACL-R.

  9. Effect of knee angle on quadriceps strength and activation after anterior cruciate ligament reconstruction

    PubMed Central

    Theuerkauf, Paul

    2015-01-01

    Quadriceps strength and activation deficits after anterior cruciate ligament (ACL) injury or surgery are typically evaluated at joint positions that are biomechanically advantageous to the quadriceps muscle. However, the effect of knee joint position and the associated changes in muscle length on strength and activation is currently unknown in this population. Here, we examined the effect of knee angle on quadriceps strength, activation, and electrically evoked torque in individuals with ACL reconstruction. Furthermore, we evaluated whether knee angle mediated the relationship between quadriceps weakness and functional performance after ACL reconstruction. Knee strength and activation were tested bilaterally at 90° and 45° of knee flexion in 11 subjects with ACL reconstruction using an interpolated triplet technique. The magnitude of electrically evoked torque at rest was used to quantify peripheral muscle contractile property changes, and the single-leg hop for distance test was used to evaluate functional performance. The results indicated that although quadriceps strength deficits were similar between knee angles, voluntary activation deficits were significantly higher in the reconstructed leg at 45° of knee flexion. On the contrary, the side-to-side evoked torque at rest ratio [i.e., (reconstructed/nonreconstructed) × 100] was significantly lower at 90° than at 45° of knee flexion. The association between quadriceps strength and functional performance was stronger at 45° of knee flexion. The results provide novel evidence that quadriceps activation is selectively affected at 45° of knee flexion and emphasize the importance of assessing quadriceps strength and activation at this position when feasible because it better captures activation deficits. PMID:25997949

  10. Combination of eccentric exercise and neuromuscular electrical stimulation to improve quadriceps function post-ACL reconstruction.

    PubMed

    Lepley, Lindsey K; Wojtys, Edward M; Palmieri-Smith, Riann M

    2015-06-01

    Neuromuscular electrical stimulation (NMES) has been shown to reduce quadriceps activation failure (QAF), and eccentric exercise has been shown to lessen muscle atrophy post-ACL reconstruction. Given that these are two critical components of quadriceps strength, intervention combining these therapies may be effective at reinstituting quadriceps function post-reconstruction. Thus, the aim of this study was to evaluate the effectiveness of a combined NMES and eccentric exercise intervention to improve the recovery of quadriceps activation and strength post-reconstruction. Thirty-six individuals post-injury were placed into four treatment groups (N&E, NMES and eccentrics; E-only, eccentrics only; N-only, NMES-only; and STND, standard of care) and ten healthy controls participated. N&E and N-only received the NMES protocol 2× per week for the first 6 weeks post-reconstruction. N&E and E-only received the eccentric exercise protocol 2× per week beginning 6 weeks post-reconstruction. Quadriceps activation was assessed via the superimposed burst technique and quantified via the central activation ratio. Quadriceps strength was assessed via maximal voluntary isomeric contractions (Nm/kg). Data was gathered on three occasions: pre-operative, 12-weeks-post-surgery and at return-to-play. No differences in pre-operative measures existed (P>0.05). E-only recovered quadriceps activation better than N-only or STND (P<0.05). N&E and E-only recovered strength better than N-only or the STND (P<0.05) and had strength values that were similar to healthy at return-to-play (P>0.05). Eccentric exercise was capable of restoring levels of quadriceps activation and strength that were similar to those of healthy adults and better than NMES alone. Level 3, Parallel longitudinal study. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Combination of Eccentric Exercise and Neuromuscular Electrical Stimulation to Improve Quadriceps Function Post-ACL Reconstruction

    PubMed Central

    Lepley, Lindsey K.; Wojtys, Edward M.; Palmieri-Smith, Riann M.

    2014-01-01

    Background Neuromuscular electrical stimulation (NMES) has been shown to reduce quadriceps activation failure (QAF), and eccentric exercise has been shown lessen muscle atrophy post-ACL reconstruction. Given that these are two critical components of quadriceps strength, intervention combining these therapies may be effective at reinstituting quadriceps function post-anterior cruciate ligament (ACL) reconstruction. Objectives To evaluate the effectiveness of a combined NMES and eccentric exercise intervention to improve the recovery of quadriceps activation and strength post-reconstruction. Design Parallel longitudinal design. Setting Laboratory. Participants Thirty-six individuals post-injury were placed into four treatment groups (N&E, NMES and eccentrics; E-only, eccentrics only; N-only, NMES-only; STND, standard of care) and ten healthy controls participated. Intervention N&E and N-only received the NMES protocol 2x per week for the first six weeks post-reconstruction. N&E and E-only received the eccentric exercise protocol 2x per week beginning six weeks post-reconstruction. Main outcome measure Quadriceps activation was assessed via the superimposed burst technique and quantified via the central activation ratio. Quadriceps strength was assessed via maximal voluntary isomeric contractions (Nm/kg). Data was gathered on three occasions: pre-operative, 12-weeks-post-surgery and at return-to-play. Results No differences in pre-operative measures existed (P>0.05). E-only recovered quadriceps activation better than N-only or STND (P<0.05). N&E and E-only recovered strength better than N-only or the STND (P<0.05) and had strength values that were similar to healthy individuals at return-to-play (P>0.05). Conclusion Eccentric exercise was capable of restoring levels of quadriceps activation and strength that were similar to those of healthy adults and better than NMES alone. PMID:25819154

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

    PubMed Central

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

    2016-01-01

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

  13. Correlation between Quadriceps Endurance and Adduction Moment in Medial Knee Osteoarthritis

    PubMed Central

    Ahn, Sung-Eun; Park, Min-Ji; Lee, Dae-Hee

    2015-01-01

    It is not clear whether the strength or endurance of thigh muscles (quadriceps and hamstring) is positively or negatively correlated with the adduction moment of osteoarthritic knees. This study therefore assessed the relationships between the strength and endurance of the quadriceps and hamstring muscles and adduction moment in osteoarthritic knees and evaluated predictors of the adduction moment. The study cohort comprised 35 patients with unilateral medial osteoarthritis and varus deformity who were candidates for open wedge osteotomy. The maximal torque (60°/sec) and total work (180°/sec) of the quadriceps and hamstring muscles and knee adduction moment were evaluated using an isokinetic testing device and gait analysis system. The total work of the quadriceps (r = 0.429, P = 0.037) and hamstring (r = 0.426, P = 0.045) muscles at 180°/sec each correlated with knee adduction moment. Preoperative varus deformity was positively correlated with adduction moment (r = 0.421, P = 0.041). Multiple linear regression analysis showed that quadriceps endurance at 180°/sec was the only factor independently associated with adduction moment (β = 0.790, P = 0.032). The adduction moment of osteoarthritic knees correlated with the endurance, but not the strength, of the quadriceps muscle. However, knee adduction moment did not correlate with the strength or endurance of the hamstring muscle. PMID:26539830

  14. Age-associated changes in hand grip and quadriceps muscle strength ratios in healthy adults.

    PubMed

    Samuel, Dinesh; Wilson, Keely; Martin, Helen J; Allen, Robert; Sayer, Avan Aihie; Stokes, Maria

    2012-06-01

    Muscle strength may decline with age differentially in the upper and lower limbs. This information is difficult to capture through a single measure. The present study therefore aimed to characterize the relative changes in handgrip and lower limb muscle strength with aging by expressing them as a ratio. Thirty-eight healthy volunteers aged 20-82 years performed maximal voluntary contractions (MVC) of quadriceps and handgrip using a custom-built transducer and a Jamar dynamometer respectively. The grip-quadriceps ratios for young adults was similar in males and females (0.75); indicating knee extensor force exceeded grip force by approximately 25%. Ratios were increased in older adults (p=0.05), and strength of the two muscle groups was approximately equal (1.1). Pearson's correlation coefficients for grip against quadriceps strength were r=0.63 (young males), r=0.83 (young females), r=0.35 (older males) and r=0.05 (older females). The ratio used demonstrated clear differences between the age groups. The reduced muscle strength with increasing age was expected, but the higher grip/quadriceps strength ratios quantify a greater loss of quadriceps than grip strength with aging. It remains to be investigated whether the relatively greater rate of decline in quadriceps strength seen in healthy older people is more exaggerated in those who are frail, which would have implications for using grip strength as a physical marker of lower limb strength and function in those at risk of immobility and falls.

  15. Quadriceps function after TKA--an in vitro study in a knee kinematic simulator.

    PubMed

    Ostermeier, S; Hurschler, C; Stukenborg-Colsman, C

    2004-03-01

    The purpose of this in vitro study was to investigate the amount of quadriceps force required to extend the knee during an isokinetic extension cycle before and after total knee arthroplasty. The magnitude of the extension torque used in simulating a constant moment extension exercise was derived from tests made using a dynamometer on patients who had received a total knee arthroplasty. Quadriceps force needed to extend the knee was measured. Human knee specimens (n=8, mean age=65 SD 7 years, all male) were tested in a kinematic knee simulating machine untreated and after implantation of two different knee prosthesis. During simulation, a hydraulic cylinder applied sufficient force to the quadriceps tendon to produce an extension moment of 31 Nm about the knee. The quadriceps forces needed to extend the knee during the physiologic simulation reached levels as high as 1238.9 N (SD 46.6). After implantation the Interax-prosthesis, quadriceps force increased up to 13.9% (P=0.003), in conjunction with resurfacing of the patella 11.9% (P=0.01). With the LCS-prosthesis implanted, quadriceps force showed a somewhat smaller increase of up to 6.6% (P=0.007). The following study helps to clarify postoperative problems related to the extensor mechanisms of the knee after implantation of total knee arthroplasty.

  16. Effects of Kinesiology Taping on Repositioning Error of the Knee Joint after Quadriceps Muscle Fatigue

    PubMed Central

    Han, Jin Tae; Lee, Jung-hoon

    2014-01-01

    [Purpose] The purpose of this study was to identify the effects of kinesiology taping on repositioning error of the knee joint after quadriceps muscle fatigue. [Subjects] Thirty healthy adults with no orthopaedic or neurological problems participated in this study. [Methods] The repositioning error of the knee joint was measured using a digital goniometer when the subjects extended their dominant-side knee to a random target angle (30°, 45°, or 60°) with their eyes closed, before and after a quadriceps muscle fatigue protocol, and after application of kinesiology tape. [Results] We found that repositioning errors of the dominant-side knee joint increased after quadriceps fatigue compared with no-fatigue conditions. However, kinesiology taping of the quadriceps muscle and patella after quadriceps fatigue significantly decreased repositioning errors of the knee joint. [Conclusion] These results suggest that quadriceps fatigue increases the repositioning error of the knee joint, whereas application of kinesiology tape decreases fatigue-induced joint repositioning error. PMID:25013297

  17. Lack of Effect of Ankle Position During the Nordic Curl on Muscle Activity of the Biceps Femoris and Medial Gastrocnemius.

    PubMed

    Comfort, Paul; Regan, Amy; Herrington, Lee; Thomas, Chris; McMahon, John; Jones, Paul

    2017-05-01

    Regular performance (~2×/wk) of Nordic curls has been shown to increase hamstring strength and reduce the risk of hamstring strain injury, although no consensus on ankle position has been provided. To compare the effects of performing Nordic curls, with the ankle in a dorsiflexed (DF) or plantar-flexed (PF) position, on muscle activity of the biceps femoris (BF) and medial gastrocnemius (MG). 15 male college athletes (age 22.6 ± 2.1 y, height 1.78 ± 0.06 m, body mass 88.75 ± 8.95 kg). A repeated-measures design was used, with participants performing 2 sets of 3 repetitions of both variations of Nordic curls, while muscle activity was assessed via surface electromyography (EMG) of the BF and MG. Comparisons of muscle activity were made by examining the normalized EMG data as the percentage of their maximum voluntary isometric contraction. Paired-samples t test revealed no significant difference in normalized muscle activity of the BF (124.5% ± 6.2% vs 128.1 ± 5.0%, P > .05, Cohen d = 0.64, power = .996) or MG (82.1% ± 3.9% vs 83.5 ± 4.8%, P > .05, Cohen d = 0.32, power = .947) during the Nordic curls in a PF or DF position, respectively. Ankle position does not influence muscle activity during the Nordic curl; however, performance of Nordic curls with the ankle in a DF position may be preferential, as this replicates the ankle position during terminal leg swing during running, which tends to be the point at which hamstring strains have been reported.

  18. Use of MMG signals for the control of powered orthotic devices: development of a rectus femoris measurement protocol.

    PubMed

    Antonelli, Michele Gabrio; Zobel, P Beomonte; Giacomin, J

    2009-01-01

    A test protocol is defined for the purpose of measuring rectus femoris mechanomyographic (MMG) signals. The protocol is specified in terms of the following: measurement equipment, signal processing requirements, human postural requirements, test rig, sensor placement, sensor dermal fixation, and test procedure. Preliminary tests of the statistical nature of rectus femoris MMG signals were performed, and Gaussianity was evaluated by means of a two-sided Kolmogorov-Smirnov test. For all 100 MMG data sets obtained from the testing of two volunteers, the null hypothesis of Gaussianity was rejected at the 1%, 5%, and 10% significance levels. Most skewness values were found to be greater than 0.0, while all kurtosis values were found to be greater than 3.0. A statistical convergence analysis also performed on the same 100 MMG data sets suggested that 25 MMG acquisitions should prove sufficient to statistically characterize rectus femoris MMG. This conclusion is supported by the qualitative characteristics of the mean rectus femoris MMG power spectral densities obtained using 25 averages.

  19. Relationships between Muscle Architecture of Rectus Femoris and Functional Parameters of Knee Motion in Adults with Down Syndrome.

    PubMed

    Valle, Maria Stella; Casabona, Antonino; Micale, Marco; Cioni, Matteo

    2016-01-01

    This study was designed to measure in vivo muscle architecture of the rectus femoris in adults with Down syndrome, testing possible relationships with functional parameters of the knee motion. Ten adults with Down syndrome and ten typically developed participated in the study. Pennation angle and thickness of the rectus femoris and subcutaneous layer of the thigh were measured via ultrasound imaging. Knee kinematics and electromyographic activity of the rectus femoris were recorded during free leg dropping. Muscle thickness was reduced and subcutaneous layer was thicker in persons with Down syndrome with respect to typically developed adults, but there were no differences in the pennation angle. The area of the rectus femoris EMG activity during the leg flexion was greater in Down syndrome with respect to typically developed adults. The leg movement velocity was lower in Down people than in controls, but the knee excursion was similar between the groups. Functional parameters correlated with pennation angle in the persons with Down syndrome and with muscle thickness in typically developed persons. The description of muscle architecture and the relationships between morphological and functional parameters may provide insights on the limits and the opportunities to overcome the inherent biomechanical instability in Down syndrome.

  20. Relationships between Muscle Architecture of Rectus Femoris and Functional Parameters of Knee Motion in Adults with Down Syndrome

    PubMed Central

    Micale, Marco; Cioni, Matteo

    2016-01-01

    This study was designed to measure in vivo muscle architecture of the rectus femoris in adults with Down syndrome, testing possible relationships with functional parameters of the knee motion. Ten adults with Down syndrome and ten typically developed participated in the study. Pennation angle and thickness of the rectus femoris and subcutaneous layer of the thigh were measured via ultrasound imaging. Knee kinematics and electromyographic activity of the rectus femoris were recorded during free leg dropping. Muscle thickness was reduced and subcutaneous layer was thicker in persons with Down syndrome with respect to typically developed adults, but there were no differences in the pennation angle. The area of the rectus femoris EMG activity during the leg flexion was greater in Down syndrome with respect to typically developed adults. The leg movement velocity was lower in Down people than in controls, but the knee excursion was similar between the groups. Functional parameters correlated with pennation angle in the persons with Down syndrome and with muscle thickness in typically developed persons. The description of muscle architecture and the relationships between morphological and functional parameters may provide insights on the limits and the opportunities to overcome the inherent biomechanical instability in Down syndrome. PMID:27896273

  1. Variable effect of steam injection level on beef muscles: semitendinosus and biceps femoris cooked in convection-steam oven.

    PubMed

    Zając, Marzena; Kącik, Sławomir; Palka, Krystyna; Widurek, Paweł

    2015-01-01

    Combi ovens are used very often in restaurants to heat up food. According to the producers the equipment allows to cook meat portions which are more tender and flavoursome comparing to conventional cooking techniques. Beef steaks from muscles semitendinosus and biceps femoris were cooked in convection-steam oven at three humidity levels: 10, 60 and 100%. Chemical composition, including total and insoluble collagen content and cook losses were analysed along with the texture and colour parameters. M. biceps femoris was the hardest and the most chewy at 100% steam saturation level and hardness measured for m. semitendinosus was the lowest at 10% of vapour injection. Changing the steam conditions in the oven chamber did not affect the detectable colour differences of m. biceps femoris, but it was significant for m. semitendinosus. Applying 100% steam saturation caused higher cook losses and the increase of insoluble collagen fractions in both analysed muscles. The results are beneficial for caterers using steam-convection ovens in terms of providing evidence that the heating conditions should be applied individually depending on the muscle used. The tenderness of m. semitendinosus muscle cooked at 10% steam saturation level was comparable to the tenderness obtained for the same muscle aged for 10 days and cooked with 100% steam saturation. Steaks from m. biceps femoris muscle should be cooked with maximum 60% saturation level to obtain higher tenderness.

  2. A Rare Case of Quadratus Femoris Muscle Rupture After Yoga Exercises.

    PubMed

    Tzaveas, Alexandros; Anastasopoulos, Nikolaos; Paraskevas, George; Natsis, Konstantinos

    2016-09-01

    We present a case of a female patient with left groin pain after intense yoga exercises. The patient presented abnormal pattern of gait with no swelling over the groin, thigh, or buttock. Magnetic resonance imaging demonstrated a tear of the quadratus femoris muscle with an associated extensive hematoma formation. Patient was treated with a rehabilitation program consisting of nonsteroidal anti-inflammatory drugs and physiotherapy. At the follow-up control, the patient had improved her pain and flexibility of the hip, and gradually she returned to daily activities and yoga exercises. Such an entity is a rare cause of hip pain after exercise and should be kept in mind by the orthopedic surgeon, in cases of gluteal pain after intense physical activity. Moreover, such a condition should be included in the diagnostic algorithm of unknown origin hip pain.

  3. Initial experience with proximal ligation for profunda femoris artery aneurysms: report of three cases.

    PubMed

    Shintani, Tsunehiro; Norimatsu, Togo; Atsuta, Koji; Saitou, Takaaki; Higashi, Shigeki; Mitsuoka, Hiroshi

    2014-04-01

    Profunda femoris artery aneurysms (PFAAs) are rare and difficult to diagnose in the early stage. They are often found due to the presence of complicated conditions, such as rapid expansion, rupture, or acute lower limb ischemia. Surgical procedures such as aneurysmectomy and endoaneurysmorrhaphy tend to be technically challenging because of the patient status and the extent of the aneurysm. We experienced three cases of PFAAs that were treated by proximal ligation (PL) without complete control of the distal branches. The exclusion of PFAAs was confirmed by duplex ultrasound or angiography at the end of the operation. There was no mortality in the perioperative period. During a 12-month follow-up, all cases exhibited complete exclusion of aneurysms with marked size reduction. Based on these findings, we propose that PL, with a careful follow-up for PFAA exclusion and distal limb circulation, could be an alternative treatment for complicated PFAAs.

  4. Effect of pain reduction on postural sway, proprioception, and quadriceps strength in subjects with knee osteoarthritis

    PubMed Central

    Hassan, B; Doherty, S; Mockett, S; Doherty, M

    2002-01-01

    Objective: To investigate whether alleviation of knee pain influences quadriceps function, proprioceptive acuity, and postural stability in patients with knee osteoarthritis (OA). Methods: A crossover, within-subject, double blind study design involving 68 subjects with painful knee OA. Each subject received an intra-articular injection into one or both knees (both if symptomatic) of either 5 ml 0.5% bupivacaine or 5 ml 0.9% saline. Two weeks later they received an injection of the alternative agent. Subjects and observer were unaware of the order of injection, which was randomly assigned. Knee pain (100 mm visual analogue scale), static postural sway, knee proprioceptive acuity, maximum voluntary contraction (MVC), and percentage activation of the quadriceps were assessed immediately before and one hour after each injection. Results: Significant pain reduction was achieved one hour post-bupivacaine (mean difference as a percentage change 56.85, 95% CI 31.01 to 73.65; p<0.001) and post-saline (mean difference as a percentage change 41.94, 95% CI 11.57 to 76.66; p< 0.001), with no significant difference between the two. Both MVC and activation increased significantly post-bupivacaine (mean percentage differences 18.83, 95% CI -31.79 to -0.26, and -11.90, 95% CI -39.53 to 2.97, respectively; both p<0.001) and post-saline (mean percentage differences -7.64, 95% CI -21.96 to 4.73, and -10.71, 95% CI -25.19 to 2.60 respectively; both p<0.001). Proprioception worsened after bupivacaine (mean percentage difference -28.15%, 95% CI -83.47 to 19.74; p=0.009), but there was no effect on postural sway; saline injection had no effects. There was no order effect, and comparison of median percentage changes showed no significant differences between injections for change in MVC, activation, proprioception, or sway. Conclusion: Reduction in knee pain through either peripheral (local anaesthetic) or central (placebo) mechanisms resulted in increased MVC. This increase, however, did

  5. The ligamentum capitis femoris: anatomic, magnetic resonance and computed tomography study.

    PubMed

    Perez-Carro, Luis; Golano, Pau; Vega, Jordi; Escajadillo, Natalia F; Rubin, Carlos G; Cerezal, Luis

    2011-01-01

    The objective of the study was to describe the normal anatomy of the ligamentum capitis femoris and to determine the neurovascular structures potentially at risk during its reconstruction. Ten cadaveric specimens of the ligamentum capitis femoris (LCF) were dissected and photographed. Magnetic resonance (MR) and Computed tomography (CT) arthrography evaluation of the anatomy of the LCF in 30 hips were performed to measure length of the ligament and to study the proximity of neurovascular structures. The anatomical study showed that the LCF has a pyramidal structure and a banded appearance. The thickness of the medial wall of the acetabulum 3 mm superior to the inferior acetabular boundary was found to be 6.7 mm (4-9 mm) at point 1 (anterior), 4.1 mm (3-7 mm) at point 2 (central), and 6.5 mm (4-9 mm) at point 3 (posterior). Central anchors or screws were found to lie within 1.7 cm (1.6-1.9 cm) of the external iliac vein and artery. Angulation of anchors in the anterior and posterior columns in the axial plane with respect to acetabular fossa floor (the Optimal Angulation Angle or OAA), is safer (0 to 45º the safest optimal angles). The sagittal angulation created by the safe pathway in the anterior and posterior columns with respect to the plane of the facies lunata in this area was also measured and termed the Optimal Angle of Penetration (OAP) with normal values being: 110º (102-123º) for the posterior column and 90º (85-94º) for the anterior column. Our results suggest that reconstruction of the LCF can be safely performed if these guidelines are followed.

  6. Results of infrageniculate bypasses using the profunda femoris artery as inflow source.

    PubMed

    Illuminati, Giulio; Calio', Francesco G; Pizzardi, Giulia; Pasqua, Rocco; Masci, Federica; Frezzotti, Francesca; Palumbo, Piergaspare; Vietri, Francesco

    2017-09-21

    When the common femoral artery is not accessible for infrainguinal bypass grafting, the profunda femoris artery (PFA) can be a valuable alternative inflow source for distal arterial revascularization. The purpose of this retrospective study was to evaluate the results of infrageniculate bypass grafting via the PFA as inflow source for critical limb ischemia. Between 1994 and 2016, 68 patients, 51 men of a mean age of 74 years, underwent an infrageniculate arterial bypass grafting for critical limb ischemia, using the PFA as inflow site. PFA was exposed at the Scarpa's triangle in 38 patients (56%) and at its medio-crural segment in 30 patients (44%). The distal anastomosis was performed on the infragenicular popliteal artery in 33 patients (48%), the peroneal artery in 14 patients (20%), the tibioperoneal trunk in 8 patients (12%), the posterior tibial artery in 8 patients (12%) and the dorsalis pedis artery in 5 patients (8%). The graft material consisted of a reversed great saphenous vein (GSV) in in 62 patients (91%) and of a 6 mm PTFE graft in 6 patients (9%). The median duration of follow-up was 51 months (range, 6 - 72 months). As main results, postoperative mortality and morbidity, overall late patients' survival, primary grafts' patency and limb salvage rate were considered. Operative mortality and morbidity were 3% and 4% respectively. Overall patients'survival, primary patency and limb salvage rate, at 36 and 60 months were, respectively, 62% and 53%, 66% and 59%, and 92% and 77%. The profunda femoris artery, both exposed at the Scarpa's triangle and at mid-thigh, is an excellent inflow source for infrageniculate revascularizations. It should remain an important part of the technical armamentarium of vascular surgeons, even in the endovascular era. Copyright © 2017. Published by Elsevier Inc.

  7. Association between patella spurs and quadriceps tendon ruptures

    PubMed Central

    Ellanti, Prasad; Moriarity, Andrew; Wainberg, Nikita; Fhoghlu, Cliodhna Ni; McCarthy, Tom

    2015-01-01

    Summary Background quadriceps tendon (QT) ruptures are significant injuries that are relatively uncommon. The diagnosis of QT ruptures is frequently missed or delayed. An association between the presence of a patella spur and QT ruptures has been suggested in the literature. Patients and methods the Hospital Inpatient Enquiry system was used to gather data on all patients who sustained a QT rupture over a six year period from 2008 to 2014. A retrospective review of the medical notes as well as radiographs was undertaken. We reviewed 200 knee radiographs of patients without QT ruptures to establish the incidence of patella spurs in our normal population. Statistical analysis was performed using SPSS version 11.5 for Windows®. Results the records of 20 consecutive patients with 21 QT ruptures were reviewed. The mean age was 60.9 yrs (range 44.9–82.1 yrs) and the majority were male (n=17; 85%). There was one bilateral QT ruptures. Patella spurs were noted in 13 cases (62%) which were significantly higher than in patients without QT rupture 19% (P≤0.05). Conclusion we noted a significantly higher incidence of patella spurs in patients with QT ruptures compared to those without. The presence of a QT rupture should be ruled out in patients with a knee injury and a patella spur on the knee radiographs. PMID:26261786

  8. Association between patella spurs and quadriceps tendon ruptures.

    PubMed

    Ellanti, Prasad; Moriarity, Andrew; Wainberg, Nikita; Fhoghlu, Cliodhna Ni; McCarthy, Tom

    2015-01-01

    quadriceps tendon (QT) ruptures are significant injuries that are relatively uncommon. The diagnosis of QT ruptures is frequently missed or delayed. An association between the presence of a patella spur and QT ruptures has been suggested in the literature. the Hospital Inpatient Enquiry system was used to gather data on all patients who sustained a QT rupture over a six year period from 2008 to 2014. A retrospective review of the medical notes as well as radiographs was undertaken. We reviewed 200 knee radiographs of patients without QT ruptures to establish the incidence of patella spurs in our normal population. Statistical analysis was performed using SPSS version 11.5 for Windows(®). the records of 20 consecutive patients with 21 QT ruptures were reviewed. The mean age was 60.9 yrs (range 44.9-82.1 yrs) and the majority were male (n=17; 85%). There was one bilateral QT ruptures. Patella spurs were noted in 13 cases (62%) which were significantly higher than in patients without QT rupture 19% (P≤0.05). we noted a significantly higher incidence of patella spurs in patients with QT ruptures compared to those without. The presence of a QT rupture should be ruled out in patients with a knee injury and a patella spur on the knee radiographs.

  9. Facilitation of quadriceps activation is impaired following eccentric exercise.

    PubMed

    Hedayatpour, N; Arendt-Nielsen, L; Falla, D

    2014-04-01

    Contracting the knee flexor muscles immediately before a maximum voluntary contraction (MVC) of knee extension increases the maximal force that the extensor muscles can exert. It is hypothesized that this phenomenon can be impaired by muscle fiber damage following eccentric exercise [delayed onset muscle soreness (DOMS)]. This study investigates the effect of eccentric exercise and DOMS on knee extension MVC immediately following a reciprocal-resisted knee flexion contraction. Electromyography (EMG) was recorded from the knee extensors and flexors of 12 healthy men during knee extension MVCs performed in a reciprocal (maximal knee extension preceded by resisted knee flexion), and nonreciprocal condition (preceded by relaxation of the knee flexors). At baseline, knee extension MVC force was greater during the reciprocal condition (P < 0.001), whereas immediately after, 24 and 48 h after eccentric exercise, the MVC force was not different between conditions. Similarly, at baseline, the EMG amplitude of the quadriceps during the MVC was larger for the reciprocal condition (P < 0.001). However, immediately after, 24 and 48 h postexercise the EMG amplitude was similar between conditions. In conclusion, eccentric exercise abolished the facilitation of force production for the knee extensors, which normally occurs when maximum knee extension is preceded by activation of the knee flexors. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Sex differences in function and structure of the quadriceps muscle in chronic obstructive pulmonary disease patients.

    PubMed

    Ausín, Pilar; Martínez-Llorens, Juana; Sabaté-Bresco, Marina; Casadevall, Carme; Barreiro, Esther; Gea, Joaquim

    2016-12-06

    Chronic obstructive pulmonary disease (COPD) is a complex disorder with extrapulmonary manifestations. Even though there is some knowledge regarding sex differences in the lung disease, little is known about extrapulmonary manifestations. Our aim was to analyze the specific profile of muscle dysfunction, structure, and biology in COPD women. Twenty-one women and 19 men with stable COPD as well as 15 controls were included. Nutritional status, physical activity, lung and muscle function, exercise capacity, and quality of life were assessed. In addition, blood, breath condensate, and quadriceps muscle samples were tested for inflammatory markers. Moreover, fiber phenotype, signs of damage-regeneration, and the expression of key genes linked to myogenesis and inflammation were assessed in the muscle. Inflammatory markers were increased in all body compartments but no correlation was found among them. Muscle dysfunction was present in both COPD groups but was more marked in women. The opposite occurred with the increase in the percentage of type II fibers that was lower in women despite a similar level of airway obstruction as in men. Female COPD also showed higher signs of muscle damage than COPD men who, in contrast, exhibited slightly higher signs of regeneration. We conclude that sex influences muscle phenotype and function in COPD.

  11. Serial Changes of Quadriceps and Hamstring Muscle Strength Following Total Knee Arthroplasty: A Meta-Analysis.

    PubMed

    Moon, Young-Wan; Kim, Hyun-Jung; Ahn, Hyeong-Sik; Lee, Dae-Hee

    2016-01-01

    This meta-analysis was performed to analyze serial changes in thigh muscles, including quadriceps and hamstring muscles, from before to one year after total knee arthroplasty (TKA). All studies sequentially comparing isokinetic quadriceps and hamstring muscle strengths between the TKA side and the contralateral uninjured limb were included in this meta-analysis. Five studies with 7 cohorts were included in this meta-analysis. The mean differences in the strengths of quadriceps and hamstring muscles between the TKA and uninjured sides were greatest three months after surgery (26.8 N∙m, 12.8 N∙m, P<0.001), but were similar to preoperative level at six months (18.4 N∙m, 7.4 N∙m P<0.001) and were maintained for up to one year (15.9 N∙m, 4.1 N∙m P<0.001). The pooled mean differences in changes in quadriceps and hamstring strengths relative to preoperative levels were 9.2 N∙m and 4.9 N∙m, respectively, three months postoperatively (P = 0.041), but were no longer significant after six months and one year. During the year after TKA, quadriceps and hamstring muscle strengths were lowest after 3 months, recovering to preoperative level after six months, but not reaching the muscle strength on the contralateral side. Relative to preoperative levels, the difference in muscle strength between the TKA and contralateral knees was only significant at three months. Because decrease of strength of the quadriceps was significantly greater than decrease in hamstring muscle strength at postoperative three months, early rehabilitation after TKA should focus on recovery of quadriceps muscle strength.

  12. The Effect of Knee Braces on Quadriceps Strength and Inhibition in Subjects With Patellofemoral Osteoarthritis.

    PubMed

    Callaghan, Michael J; Parkes, Matthew J; Felson, David T

    2016-01-01

    Secondary analysis of a randomized controlled trial. The use of external supports has been questioned because they may lead to weakness in the surrounding muscles. To our knowledge, there is no investigation into the effect of knee supports or braces on quadriceps muscle strength and quadriceps inhibition in individuals with patellofemoral joint (PFJ) osteoarthritis (OA). To investigate the effects of a flexible knee support on quadriceps maximum voluntary contraction (MVC) and arthrogenous muscle inhibition (AMI) in patients with PFJ OA. The study included 108 participants who had at least 3 months of patellofemoral pain and a Kellgren-Lawrence score of 2 or 3 for PFJ OA. The participants were randomized to a group that wore a flexible knee support (brace) or a group that did not wear a support (no brace) in a 6-week randomized controlled trial, followed by an open-label trial, in which all participants wore the brace for a total of 12 weeks. Quadriceps MVC, measured isometrically, and quadriceps AMI, measured by twitch interpolation, were assessed at the 6-week and 12-week time points. After 6 weeks, MVC did not differ between the brace and no-brace groups (9.09 Nm; 95% confidence interval [CI]: -4.89, 23.07; P = .20). Arthrogenous muscle inhibition significantly decreased in the brace group (-8.62%; 95% CI: -13.90%, -3.33%; P = .002). After 12 weeks, in all of the participants who wore a flexible knee support, MVC increased by 7.98 Nm (95% CI: 2.52, 13.45; P = .004) and AMI decreased (-8.42%; 95% CI: -11.48%, -5.36%; P<.001). Although statistically significant, these results have doubtful clinical significance. A patellofemoral flexible knee support in participants with PFJ OA does not have an adverse effect on quadriceps MVC or AMI. Using a knee support should not be discouraged because of concerns about deleterious effects on quadriceps strength and inhibition. Therapy, level 1b.

  13. The associations between quadriceps muscle strength, power, and knee joint mechanics in knee osteoarthritis: A cross-sectional study.

    PubMed

    Murray, Amanda M; Thomas, Abbey C; Armstrong, Charles W; Pietrosimone, Brian G; Tevald, Michael A

    2015-12-01

    Abnormal knee joint mechanics have been implicated in the pathogenesis and progression of knee osteoarthritis. Deficits in muscle function (i.e., strength and power) may contribute to abnormal knee joint loading. The associations between quadriceps strength, power and knee joint mechanics remain unclear in knee osteoarthritis. Three-dimensional motion analysis was used to collect peak knee joint angles and moments during the first 50% of stance phase of gait in 33 participants with knee osteoarthritis. Quadriceps strength and power were assessed using a knee extension machine. Strength was quantified as the one repetition maximum. Power was quantified as the peak power produced at 40-90% of the one repetition maximum. Quadriceps strength accounted for 15% of the variance in peak knee flexion angle (P=0.016). Quadriceps power accounted for 20-29% of the variance in peak knee flexion angle (P<0.05). Quadriceps power at 90% of one repetition maximum accounted for 9% of the variance in peak knee adduction moment (P=0.05). These data suggest that quadriceps power explains more variance in knee flexion angle and knee adduction moment during gait in knee osteoarthritis than quadriceps strength. Additionally, quadriceps power at multiple loads is associated with knee joint mechanics and therefore should be assessed at a variety of loads. Taken together, these results indicate that quadriceps power may be a potential target for interventions aimed at changing knee joint mechanics in knee osteoarthritis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Original Research: Central and peripheral quadriceps fatigue in young and middle-aged untrained and endurance-trained men: A comparative study.

    PubMed

    Bachasson, Damien; Decorte, Nicolas; Wuyam, Bernard; Millet, Guillaume Y; Verges, Samuel

    2016-10-01

    This study aimed to compare quadriceps function (i.e. strength, endurance, central, and peripheral fatigue) of young (Young-UnTr) and middle-aged (MidAge-UnTr) untrained men and young endurance-trained men (Young-Tr). Twenty-four male subjects (eight Young-UnTr (26 ± 4 yr), eight Young-Tr (29 ± 3 yr), and eight MidAge-UnTr (56 ± 4 yr) performed a maximal cycling test to assess their fitness level. On a separate visit, subjects performed sets of 10 intermittent (5-s on/5-s off) isometric contractions starting at 10% maximum voluntary contraction (MVC), with 10% MVC increments from one set to another until exhaustion. Electrophysiological and mechanical (e.g. twitch) evoked responses elicited with magnetic femoral nerve stimulation in the relaxed muscle and during MVC (i.e. estimation of voluntary activation using the interpolated twitch technique) were measured at baseline and after each set to assess peripheral and central fatigue, respectively. Endurance (= total number of contractions) was also evaluated. Young-UnTr exhibited larger reductions in evoked quadriceps mechanical responses than MidAge-UnTr and Young-Tr after identical standardized muscle loading (e.g. after the 50% MVC set, reduction in single potentiated twitch was -36 ± 9%, -21±16%, and -2 ± 4%, respectively). At both 50% MVC set and exhaustion, MidAge-UnTr exhibited similar reduction in maximal voluntary activation and displayed similar endurance compared to Young-UnTr. Young-Tr exhibited greater endurance than Young-UnTr without significant changes in maximal voluntary activation throughout the test. This study provides robust comparative data regarding the influence of chronic exposure to endurance training and middle-aged on central and peripheral quadriceps fatigability and endurance. Endurance-trained subjects showed smaller level of peripheral fatigue and displayed no significant central fatigue, even at exhaustion and despite greater endurance performance. Our

  15. Quadriceps and hamstrings fatigue alters hip and knee mechanics.

    PubMed

    Thomas, Abbey C; McLean, Scott G; Palmieri-Smith, Riann M

    2010-05-01

    Neuromuscular fatigue exacerbates abnormal landing strategies, which may increase noncontact anterior cruciate ligament (ACL) injury risk. The synergistic actions of quadriceps and hamstrings (QH) muscles are central to an upright landing posture, though the precise effect of simultaneous fatigue of these muscles on landing and ACL injury risk is unclear. Elucidating neuromechanical responses to QH fatigue thus appears important in developing more targeted fatigue-resistance intervention strategies. The current study thus aimed to examine the effects of QH fatigue on lower extremity neuromechanics during dynamic activity. Twenty-five healthy male and female volunteers performed three single-leg forward hops onto a force platform before and after QH fatigue. Fatigue was induced through sets of alternating QH concentric contractions, on an isokinetic dynamometer, until the first five repetitions of a set were performed at least 50% below QH peak torque. Three-dimensional hip and knee kinematics and normalized (body mass x height) kinetic variables were quantified for pre- and postfatigue landings and subsequently analyzed by way of repeated- measures mixed-model ANOVAs. QH fatigue produced significant increases in initial contact (IC) hip internal rotation and knee extension and external rotation angles (p < .05), with the increases in knee extension and external rotation being maintained at the time of peak vertical ground reaction force (vGRF) (p < .05). Larger knee extension and smaller knee flexion and external rotation moments were also evident at peak vGRF following fatigue (p < .05). Females landed with greater hip flexion and less abduction than males at both IC and peak vGRF as well as greater knee flexion at peak vGRF (p < .05). The peak vGRF was larger for females than males (p < .05). No sex x fatigue effects were found (p > .05). Fatigue of the QH muscles altered hip and knee neuromechanics, which may increase the risk of ACL injury. Prevention programs

  16. Measurement of quadriceps endurance by fNIRS

    NASA Astrophysics Data System (ADS)

    Erdem, Devrim; Şayli, Ömer; Karahan, Mustafa; Akin, A.

    2006-02-01

    In this paper, the changes in muscle deoxygenation trends during a sustained isometric quadriceps (chair squat/half squat) endurance exercise were evaluated among twelve male subjects and the relationship between muscle oxygenation and endurance times was investigated by means of functional near-infrared spectroscopy (fNIRS). Neuromuscular activation and predictions of muscle performance decrements during extended fatiguing task was investigated by means of surface electromyography (sEMG). The results of the study showed that in the subjects who maintained exercise longer than five minutes (group 1), mean Hb recovery time (33 [sec.]) was 37.4% less than the others (group 2, 52.7 [sec.]). Also mean HbO II decline amplitude (2.53 [a.u.] in group 1 and 2.07 [a.u.] in group 2) and oxy decline amplitude (8.4 [a.u.] in group 1 and 3.04 [a.u.] in group 2) in the beginning of squat exercise are found to be 22.6% and 176.9% bigger in these group. For the EMG parameters, mean slope of MNF and MDF decline are found to be 57.5% and 42.2% bigger in magnitude in group 2 which indicates higher degree of decrement in mean and median frequencies although their mean squat duration time is less. This indicates higher index of fatigue for this group. It is concluded that training leads to altered oxygenation and oxygen extraction capability in the exercising muscle and investigated fNIRS parameters could be used for endurance evaluation.

  17. Interplay between body stabilisation and quadriceps muscle activation capacity.

    PubMed

    Bampouras, Theodoros M; Reeves, Neil D; Baltzopoulos, Vasilios; Maganaris, Constantinos N

    2017-03-22

    The study aimed to distinguish the effect of stabilisation and muscle activation on quadriceps maximal isometric voluntary contraction (MVC) torque generation. Nine subjects performed (a) an MVC with restrained leg and pelvis (Typical MVC), (b) a Typical MVC with handgrip (Handgrip MVC), (c) an MVC focusing on contracting the knee extensors only (Isolated knee extension MVC), and (d) an MVC with unrestrained leg and pelvis (Unrestrained MVC). Torque and activation capacity between conditions were compared with repeated measures ANOVA and dependent t-tests. EMG (from eleven remote muscles) was compared using Friedman's and Wilcoxon. Typical MVC (277.2±49.6Nm) and Handgrip MVC (261.0±55.4Nm) were higher than Isolated knee extension MVC (210.2±48.3Nm, p<0.05) and Unrestrained MVC (195.2±49.7Nm, p<0.05) torque. Typical MVC (83.1±15.9%) activation was higher than Isolated knee extension MVC (68.9±24.3%, p<0.05), and both Typical MVC and Handgrip MVC (81.8±17.4%) were higher than Unrestrained MVC (64.9±16.2%, p<0.05). Only flexor carpi radialis, biceps brachii, triceps brachii and external oblique muscles showed EMG differences, with Isolated knee extension MVC consistently lower than Typical MVC or Handgrip MVC. Stabilisation of the involved segments is the prime concern allowing fuller activation of the muscle, reinforcing the need for close attention to stabilisation during dynamometry-based knee joint functional assessment.

  18. Measurement of ageing effects on muscle tone and mechanical properties of rectus femoris and biceps brachii in healthy males and females using a novel hand-held myometric device.

    PubMed

    Agyapong-Badu, Sandra; Warner, Martin; Samuel, Dinesh; Stokes, Maria

    2016-01-01

    Age and gender effects on muscle tone and mechanical properties have not been studied using hand-held myometric technology. Monitoring changes in muscle properties with ageing in community settings may provide a valuable assessment tool for detecting those at risk of premature decline and sarcopenia. This study aimed to provide objective data on the effects of ageing and gender on muscle tone and mechanical properties of quadriceps (rectus femoris) and biceps brachii muscles. In a comparative study of 123 healthy males and females (aged 18-90 years; n=61 aged 18-35; n=62 aged 65-90) muscle tone, elasticity and stiffness were measured using the MyotonPRO device. Stiffness was greater and elasticity lower in older adults for BB and RF (p<0.001). Tone was significantly greater in older adults for BB but not for RF when data for males and females were combined (p=0.28). There were no gender differences for BB in either age group. In RF, males had greater stiffness (young males 292 vs females 233 N/m; older males 328 vs females 311 N/m) and tone (young 16.4 vs 13.6 Hz; older 16.7 vs 14.9 Hz). Elasticity in RF was lower in young males than females but did not differ between the older groups (both males and females log decrement 1.6). Stiffness and tone increased with ageing and elasticity decreased. These findings have implications for detecting frailty using a novel biomarker. Age and gender differences are important to consider when assessing effects of pathological conditions on muscle properties in older people. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Quadriceps muscle function after rehabilitation with cryotherapy in patients with anterior cruciate ligament reconstruction.

    PubMed

    Hart, Joseph M; Kuenze, Christopher M; Diduch, David R; Ingersoll, Christopher D

    2014-01-01

    Persistent muscle weakness after anterior cruciate ligament (ACL) reconstruction may be due to underlying activation failure and arthrogenic muscle inhibition (AMI). Knee-joint cryotherapy has been shown to improve quadriceps function transiently in those with AMI, thereby providing an opportunity to improve quadriceps muscle activation and strength in patients with a reconstructed ACL. To compare quadriceps muscle function in patients with a reconstructed ACL who completed a 2-week intervention including daily cryotherapy (ice bag), daily exercises, or both. Cross-sectional study. Laboratory. A total of 30 patients with reconstructed ACLs who were at least 6 months post-index surgery and had measurable quadriceps AMI. The patients attended 4 supervised visits over a 2-week period. They were randomly assigned to receive 20 minutes of knee-joint cryotherapy, 1 hour of therapeutic rehabilitation exercises, or cryotherapy followed by exercises. We measured quadriceps Hoffmann reflex, normalized maximal voluntary isometric contraction torque, central activation ratio using the superimposed-burst technique, and patient-reported outcomes before and after the intervention period. After the 2-week intervention period, patients who performed rehabilitation exercises immediately after cryotherapy had higher normalized maximal voluntary isometric contraction torques (P = .002, Cohen d effect size = 1.4) compared with those who received cryotherapy alone (P = .16, d = 0.58) or performed exercise alone (P = .16, d = 0.30). After ACL reconstruction, patients with AMI who performed rehabilitation exercises immediately after cryotherapy experienced greater strength gains than those who performed cryotherapy or exercises alone.

  20. Decrease in eccentric quadriceps and hamstring strength in recreational alpine skiers after prolonged skiing

    PubMed Central

    Koller, Arnold; Fuchs, Birgit; Leichtfried, Veronika; Schobersberger, Wolfgang

    2015-01-01

    Background To effectively prevent injury in recreational alpine skiing, it is important to identify modifiable risk factors that can be targeted through exercise and training. Fatigue is a potential risk factor in recreational skiing, but no investigations have evaluated concentric/eccentric quadriceps and hamstring fatigue in recreational skiers. We tested the hypothesis that recreational skiing is associated with more pronounced eccentric as compared with concentric muscle fatigue. Methods Twenty-four healthy and fit recreational skiers (14 male and 10 female) performed an isokinetic muscle test 1 day before, 1 h after, and 24 h after a 4 h skiing session. The testing protocol consisted of concentric and eccentric quadriceps and hamstring contractions for both legs. Results Eccentric peak hamstring torque (both thighs) and eccentric peak quadriceps torque (left thigh) were reduced in male and female participants (p<0.05). Reduced peak torques were still present 24 h after the skiing session. There were no other significant findings. Summary Recreational skiing is associated with prolonged (at least 24 h) eccentric quadriceps (left thigh) and hamstring (both thighs) fatigue in men and women. Eccentric quadriceps and hamstring fatigue may be a potential injury risk factor in male and female recreational skiers. This provides some justification for judicious use of additional eccentric training modalities for alpine skiing. PMID:27900115

  1. Decrease in eccentric quadriceps and hamstring strength in recreational alpine skiers after prolonged skiing.

    PubMed

    Koller, Arnold; Fuchs, Birgit; Leichtfried, Veronika; Schobersberger, Wolfgang

    2015-01-01

    To effectively prevent injury in recreational alpine skiing, it is important to identify modifiable risk factors that can be targeted through exercise and training. Fatigue is a potential risk factor in recreational skiing, but no investigations have evaluated concentric/eccentric quadriceps and hamstring fatigue in recreational skiers. We tested the hypothesis that recreational skiing is associated with more pronounced eccentric as compared with concentric muscle fatigue. Twenty-four healthy and fit recreational skiers (14 male and 10 female) performed an isokinetic muscle test 1 day before, 1 h after, and 24 h after a 4 h skiing session. The testing protocol consisted of concentric and eccentric quadriceps and hamstring contractions for both legs. Eccentric peak hamstring torque (both thighs) and eccentric peak quadriceps torque (left thigh) were reduced in male and female participants (p<0.05). Reduced peak torques were still present 24 h after the skiing session. There were no other significant findings. Recreational skiing is associated with prolonged (at least 24 h) eccentric quadriceps (left thigh) and hamstring (both thighs) fatigue in men and women. Eccentric quadriceps and hamstring fatigue may be a potential injury risk factor in male and female recreational skiers. This provides some justification for judicious use of additional eccentric training modalities for alpine skiing.

  2. Anterior tibial translation during different isokinetic quadriceps torque in anterior cruciate ligament deficient and nonimpaired individuals.

    PubMed

    Kvist, J; Karlberg, C; Gerdle, B; Gillquist, J

    2001-01-01

    Factorial quasi-experimental design. To quantify the effect of different levels of isokinetic concentric and eccentric knee extensor torques on the anterior tibial translation in subjects with anterior cruciate ligament (ACL) deficiency. Electromyogram (EMG) activity of 4 leg muscles was recorded in order to detect any co-activation of extensors and flexors. The rehabilitation after an ACL injury is of importance for the functional outcome of the patient. In order to construct a rehabilitation program after that injury, it is important to understand the in vivo relationships between muscle force and tibial translation. Twelve patients with unilateral ACL injury and 11 uninjured volunteers performed 36 repetitions of a quadriceps contraction at different isokinetic concentric and eccentric torque levels, on a KinCom machine (60 degrees x s(-1)), with simultaneous recordings of tibial translation (CA-4000) and EMG activity from quadriceps and hamstrings muscles. Tibial translations and EMG levels were normalized to the maximum of each subject. The individual anterior tibial translation increased with increased quadriceps torque in a similar manner in both quadriceps contraction modes in all legs tested. During concentric mode, translation was similar in all groups, but during eccentric mode, the mean translation was 38% larger in the ACL injured knees. No quadriceps-hamstrings co-activation occurred in any test or group. An ACL deficient knee can limit the translation within a normal space during concentric muscle activity but not during eccentric activity. That limitation depends on other mechanisms than hamstrings co-activation.

  3. Isokinetic torque peak and hamstrings/quadriceps ratios in endurance athletes with anterior cruciate ligament laxity.

    PubMed

    Portes, Eliane Magaieski; Portes, Leslie Andrews; Botelho, Viviane Gomes; Souza Pinto, Sérgio de

    2007-04-01

    To evaluate torque and the hamstring/quadriceps ratio of the knee of athletes with and without anterior cruciate ligament laxity. Twenty-eight male athletes, 19 without anterior cruciate ligament laxity and 9 with anterior cruciate ligament laxity, were evaluated with an isokinetic machine model Cybex 770. The peak torque of quadriceps and hamstrings was compared, and the hamstring/quadriceps ratio on the constant angular speed of 60 masculine per second were also compared. In athletes with anterior cruciate ligament laxity, the peak torque values (right and left knees) of flexors (120 +/- 15 and 116 +/- 15 Nm) and of extensors (218 +/- 36 Nm and 207 +/- 26 Nm) were not different than those of athletes without laxity (109 +/- 21 Nm and 111 +/- 22 Nm; 191 +/- 5 Nm and 188 +/- 35 Nm). The hamstring/quadriceps ratio of athletes with laxity (right: 57 +/- 6% and left: 56 +/- 8%) did not differ from those without anterior cruciate ligament laxity (right: 58 +/- 9% and left: 58 +/- 7%). The anterior cruciate ligament laxity of long distances running athletes did not significantly alter the peak torque of flexors and of extensors or the hamstring/quadriceps ratio.

  4. Joint awareness after total knee arthroplasty is affected by pain and quadriceps strength.

    PubMed

    Hiyama, Y; Wada, O; Nakakita, S; Mizuno, K

    2016-06-01

    There is a growing interest in the use of patient-reported outcomes to provide a more patient-centered view on treatment. Forgetting the artificial joint can be regarded as the goal in joint arthroplasty. The goals of the study were to describe changes in joint awareness in the artificial joint after total knee arthroplasty (TKA), and to determine which factors among pain, knee range of motion (ROM), quadriceps strength, and functional ability affect joint awareness after TKA. Patients undergoing TKA demonstrate changes in joint awareness and joint awareness is associated with pain, knee ROM, quadriceps strength, and functional ability. This prospective cohort study comprised 63 individuals undergoing TKA, evaluated at 1, 6, and 12 months postoperatively. Outcomes included joint awareness assessed using the Forgotten Joint Score (FJS), pain score, knee ROM, quadriceps strength, and functional ability. Fifty-eight individuals completed all postoperative assessments. All measures except for knee extension ROM improved from 1 to 6 months. However, there were no differences in any measures from 6 to 12 months. FJS was affected most greatly by pain at 1 month and by quadriceps strength at 6 and 12 months. Patients following TKA demonstrate improvements in joint awareness and function within 6 months after surgery, but reach a plateau from 6 to 12 months. Quadriceps strength could contribute to this plateau of joint awareness. Prospective cohort study, IV. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  5. Quadriceps Strength Asymmetry Following ACL Reconstruction Alters Knee Joint Biomechanics and Functional Performance at Time of Return to Activity

    PubMed Central

    Palmieri-Smith, RM; Lepley, LK

    2016-01-01

    Background Quadriceps strength deficits are observed clinically following anterior cruciate injury and reconstruction and are often not overcome despite rehabilitation. Given that quadriceps strength may be important for achieving symmetrical joint biomechanics and promoting long-term joint health, determining the magnitude of strength deficits that lead to altered mechanics is critical. Purpose To determine if the magnitude of quadriceps strength asymmetry alters knee and hip biomechanical symmetry, as well as functional performance and self-reported function. Study Design Cross-Sectional study. Methods Seventy-three patients were tested at the time they were cleared for return to activity following ACL reconstruction. Quadriceps strength and activation, scores on the International Knee Documentation Committee form, the hop for distance test, and sagittal plane lower extremity biomechanics were recorded while patients completed a single-legged hop. Results Patients with high and moderate quadriceps strength symmetry had larger central activation ratios as well as greater limb symmetry indices on the hop for distance compared to patients with low quadriceps strength symmetry (P<0.05). Similarly, knee flexion angle and external moment symmetry was higher in the patients with high and moderate quadriceps symmetry compared to those with low symmetry (P<0.05). Quadriceps strength was found to be associated with sagittal plane knee angle and moment symmetry (P<0.05). Conclusion Patients with low quadriceps strength displayed greater movement asymmetries at the knee in the sagittal plane. Quadriceps strength was related to movement asymmetries and functional performance. Rehabilitation following ACL reconstruction needs to focus on maximizing quadriceps strength, which likely will lead to more symmetrical knee biomechanics. PMID:25883169

  6. The Bernese periacetabular osteotomy: is transection of the rectus femoris tendon essential?

    PubMed

    Novais, Eduardo N; Kim, Young-Jo; Carry, Patrick M; Millis, Michael B

    2014-10-01

    The Bernese periacetabular osteotomy (PAO) traditionally is performed using the iliofemoral or the ilioinguinal approach with transection of the rectus femoris tendon attachments. Although a rectus-preserving approach has been developed, there is limited direct comparison data regarding the surgical safety, radiographic correction, and improvement in hip pain and function between the rectus-preserving and the classic approaches. The purposes of this study were to determine whether preserving the rectus femoris tendon attachment would (1) reduce intraoperative blood loss and length of surgery; (2) improve Harris hip scores (HHS); (3) decrease the rate of complications; and (4) affect the radiographic correction when compared with the classic approach. A retrospective matched cohort study was used to compare the endpoints listed above after PAO using a rectus-preserving approach versus the classic approach. Operative blood loss, preoperative and postoperative hematocrit, duration of surgery, HHS, and postoperative complications were recorded for the two groups. Pelvic radiographs were reviewed for measurement of the lateral center-edge angle, anterior center-edge angle, and Tönnis acetabular inclination angle. A total of 64 patients were included (32 in each group). Followup was at a minimum of 1 year (mean, 20 months; range, 13-44 months). Blood loss (p = 0.2405), hematocrit change (p = 0.3277), and operative time (p = 0.3960) were similar between groups. At latest followup, the HHS improved in the rectus-preserving (mean improvement, 25; 95% CI, 21-29; p < 0.0001) and control groups (mean improvement, 21; 95% CI, 17-25; p < 0.0001) with no difference in HHS improvement between the groups (mean difference, 4.3; 95% CI, -1.6 to 10.1; p = 0.1523). The complication rate was 12.5% (four of 32) in the rectus-preserving group and 25% (eight of 32) in the classic approach groups, respectively (p = 0.2002). The rectus-preserving approach allowed for similar lateral center

  7. Quadriceps autograft to treat Achilles Chronic tears: a simple surgical technique.

    PubMed

    Arriaza, Rafael; Gayoso, Raquel; López-Vidriero, Emilio; Aizpurúa, Jesús; Agrasar, Carlos

    2016-03-05

    Chronic Achilles tendon tears could hinder patients and represent a challenge to surgeons. Although many different surgical techniques have been proposed for reconstruction of a neglected Achilles tendon rupture, there is no clear evidence to support one technique over the others, but the use of a technique that could allow for an "anatomical" reconstructions seems desirable. The present paper describes a new anatomic Achilles tendon reconstruction for chronic tears, using a quadriceps tendon autograft as graft source, with PRP injected into the graft and the neighbor tissue, and fixation in a bone trough with a simple small fragments screw. Autologous quadriceps tendon graft seems an excellent option, although -surprisingly- has received little attention until now. Autologous Quadriceps tendon graft (in bone-tendon configuration) is a simple technique that could allow surgeons to reconstruct tissue defects in the Achilles tendon with non-expensive hardware.

  8. Redox balance following magnetic stimulation training in the quadriceps of patients with severe COPD.

    PubMed

    Bustamante, Víctor; Casanova, Juan; López de Santamaría, Elena; Mas, Sandra; Sellarés, Jacobo; Gea, Joaquim; Gáldiz, Juan B; Barreiro, Esther

    2008-11-01

    In severe COPD patients, oxidative stress, which is involved in their peripheral muscle dysfunction, increases in response to exercise. In this study, muscle oxidative stress was explored after quadriceps magnetic stimulation training. A randomized controlled study was conducted on very severe COPD patients, who underwent quadriceps magnetic stimulation training for 8 weeks. A control group was also studied. In both groups, vastus lateralis specimens were obtained before and after the 8-week period. Muscle protein carbonylation and nitration and antioxidant enzymes were determined using immunoblotting and proportions and sizes of type I and II fibres using immunohistochemistry. Compared to controls, magnetic stimulation muscle training did not modify redox balance, whilst inducing a significant increase in type I fibre sizes. In severe COPD patients, it is concluded that quadriceps magnetic stimulation training was a well-tolerated therapeutic intervention, which did not enhance muscle oxidative stress, while increasing the size of slow-twitch fibres.

  9. Young athletes after ACL reconstruction with quadriceps strength asymmetry at the time of return-to-sport demonstrate decreased knee function 1 year later.

    PubMed

    Ithurburn, Matthew P; Altenburger, Alex R; Thomas, Staci; Hewett, Timothy E; Paterno, Mark V; Schmitt, Laura C

    2017-09-16

    Quadriceps femoris (QF) strength deficits at return-to-sport (RTS) after ACL reconstruction (ACLR) contribute to decreased knee function at the same time point. However, the impact of QF strength at RTS on longitudinal function has not been examined. The purpose of this study was to test the hypothesis that young athletes after ACLR with QF strength asymmetry at RTS would demonstrate decreased knee-related function and lower proportions of functional recovery at 1 year post-RTS compared to young athletes following ACLR with nearly symmetric QF strength at RTS. Participants included 76 young athletes (74% female; mean age at RTS = 17.3 years) after primary, unilateral ACLR, cleared to RTS, and followed for 1 year after RTS. At the time of RTS, QF strength was quantified on an isokinetic dynamometer and a Limb Symmetry Index (LSI) was calculated [(involved/uninvolved) × 100%]. The cohort was subdivided into two groups based on RTS QF LSI: high quadriceps (HQ; LSI ≥ 90%; n = 36) and low quadriceps (LQ; LSI < 85%; n = 36). The cohort was followed for 1 year post-RTS, and knee-related function was assessed using the International Knee Documentation Committee subjective form (IKDC), the Knee Injury and Osteoarthritis Outcome Score (KOOS), and LSI of single-leg hop tests. Functional recovery at 1 year post-RTS was defined as KOOS scores above literature-reported cut-offs. While the HQ group demonstrated higher symmetry on all 1 year post-RTS hop tests, only the triple-hop test (p = 0.020) was found to be statistically different. Similarly, while the HQ group scored higher on all 1 year post-RTS self-reported knee function measures, only differences on the KOOS-Sport/Rec score (p = 0.039) and IKDC score (p = 0.011) were statistically different. Additionally, the HQ group demonstrated higher proportions of functional recovery at 1 year post-RTS than the LQ group on the KOOS-Symptoms (HQ: 88.9%, LQ: 69.4%; p = 0.040) and KOOS-Sport/Rec (HQ: 91

  10. In vivo and noninvasive three-dimensional patellar tracking induced by individual heads of quadriceps.

    PubMed

    Lin, Fang; Wang, Guangzhi; Koh, Jason L; Hendrix, Ronald W; Zhang, Li-Qun

    2004-01-01

    Unbalanced actions of the quadriceps components are closely linked to patellar mal-tracking and patellofemoral pain syndrome. However, it is not clear how individual quadriceps components pull and rotate the patella three dimensionally. The purpose of this study was to investigate in vivo and noninvasively patellar tracking induced by individual quadriceps components. Individual quadriceps component was activated selectively through electrical stimulation at the muscle motor point, and the resulting patellar tracking was measured in vivo and noninvasively in 18 knees of 12 subjects. The in vivo and noninvasively patellar tracking was corroborated with in vivo fluoroscopy and in vitro cadaver measurements. Vastus medialis (VM) mainly pulled the patella first in the medial and second in the proximal directions and vastus lateralis (VL) pulled first in the proximal and second in the lateral directions. The oblique portion (VMO) of the VM pulled the patella mainly medially and the longus portion (VML) more proximally. Medial tilt was the major patellar rotation induced by VMO contraction at full knee extension. With the knee at the more flexed positions, the amplitude of patellar movement induced by comparable quadriceps contractions was reduced significantly compared to that at full knee extension, and VMO changed its main action from extending to flexing the patella. The medial and lateral quadriceps components moved the patella in rather different directions, and rotated the patella differently about the mediolateral tilt and mediolateral rotation axes but similarly in extension. The approach can be used to investigate patellar tracking in vivo and noninvasively in both healthy subjects and patients with patellofemoral disorder and patellar malalignment.

  11. Quadriceps weakness predicts risk for knee joint space narrowing in women in the MOST cohort

    PubMed Central

    Segal, Neil A; Glass, Natalie A; Torner, James; Yang, Mei; Felson, David T; Sharma, Leena; Nevitt, Michael; Lewis, Cora E.

    2010-01-01

    Objective Quadriceps weakness has been reported with incident but not progressive knee osteoarthritis (OA) in longitudinal studies. This study examined the relationship between quadriceps strength and worsening of knee joint space narrowing (JSN) over 30 months. Methods Longitudinal, observational study of adults aged 50-79 years with OARSI JSN score <3 at baseline. Baseline measures included bilateral weight-bearing fixed flexion radiographs, isokinetic concentric quadriceps and hamstring strength, height and weight, and physical activity. Hamstring:quadriceps (H:Q) strength ratios also were evaluated. Worsening was defined as an increase in JSN score in the tibiofemoral and/or patellofemoral compartments on 30-month radiographs or total knee replacement. Knee-based analyses used generalized estimating equations, stratified by sex, to assess relationships between strength and knee JSN while controlling for covariance between knees within subjects as well as age, BMI, history of knee injury and/or surgery, physical activity level and alignment. Results 3856 knees (1602 male and 2254 female) with JSN score <3 at baseline and no missing follow-up data were included. Mean±SD age was 61.6±8.1 in men and 62.2±7.7 in women. Women in the lowest tertile of quadriceps strength had an increased risk of whole knee JSN (OR=1.66, 95% CI=1.26, 2.19) and tibiofemoral JSN (OR=1.69, 95% CI=1.26, 2.28). However, no associations were found between strength and JSN in men or H:Q<0.6 and JSN in men or women. Conclusions In women but not in men, quadriceps weakness was associated with increased risk for tibiofemoral and whole knee JSN. PMID:20188686

  12. “Central” Quadriceps Tendon Harvest With Patellar Bone Plug: Surgical Technique Revisited

    PubMed Central

    Scully, William F.; Wilson, David J.; Arrington, Edward D.

    2013-01-01

    The objective of this article is to review the surgical technique for quadriceps tendon graft harvest while highlighting an additional technical note that has not been previously emphasized. The quadriceps tendon typically inserts eccentrically on the superior pole of the patella. By shifting the soft-tissue harvest to a location just off the medial edge of the tendon, the adjoining patellar bone plug will be centered on the superior pole of the patella, reducing the risk of an iatrogenic patellar fracture. PMID:24400194

  13. Skeletal muscle alterations in chronic heart failure: differential effects on quadriceps and diaphragm

    PubMed Central

    Mangner, Norman; Weikert, Bettina; Bowen, T Scott; Sandri, Marcus; Höllriegel, Robert; Erbs, Sandra; Hambrecht, Rainer; Schuler, Gerhard; Linke, Axel; Gielen, Stephan; Adams, Volker

    2015-01-01

    Background Chronic heart failure (CHF) results in limb and respiratory muscle weakness, which contributes to exercise intolerance and increased morbidity and mortality, yet the molecular mechanisms remain poorly understood. Therefore, we aimed to compare parameters of antioxidative capacity, energy metabolism, and catabolic/anabolic balance in diaphragm and quadriceps muscle in an animal model of CHF. Methods Ligation of the left anterior descending coronary artery (n = 13) or sham operation (n = 11) was performed on Wistar Kyoto rats. After 12 weeks, echocardiography and invasive determination of maximal rates of left ventricular (LV) pressure change were performed. Antioxidative and metabolic enzyme activities and expression of catabolic/anabolic markers were assessed in quadriceps and diaphragm muscle. Results Ligated rats developed CHF (i.e. severe LV dilatation, reduced LV ejection fraction, and impaired maximal rates of LV pressure change; P < 0.001). There was a divergent response for antioxidant enzymes between the diaphragm and quadriceps in CHF rats, with glutathione peroxidase and manganese superoxide dismutase activity increased in the diaphragm but reduced in the quadriceps relative to shams (P < 0.01). Metabolic enzymes were unaltered in the diaphragm, but cytochrome c oxidase activity (P < 0.01) decreased and lactate dehydrogenase activity (P < 0.05) increased in the quadriceps of CHF animals. Protein expression of the E3 ligase muscle ring finger 1 and proteasome activity were increased (P < 0.05) in both the diaphragm and quadriceps in CHF rats compared with shams. Conclusion Chronic heart failure induced divergent antioxidative and metabolic but similar catabolic responses between the diaphragm and quadriceps. Despite the quadriceps demonstrating significant impairments in CHF, apparent beneficial adaptations of an increased antioxidative capacity were induced in the diaphragm. Nevertheless, muscle ring finger 1 and

  14. Skeletal muscle alterations in chronic heart failure: differential effects on quadriceps and diaphragm.

    PubMed

    Mangner, Norman; Weikert, Bettina; Bowen, T Scott; Sandri, Marcus; Höllriegel, Robert; Erbs, Sandra; Hambrecht, Rainer; Schuler, Gerhard; Linke, Axel; Gielen, Stephan; Adams, Volker

    2015-12-01

    Chronic heart failure (CHF) results in limb and respiratory muscle weakness, which contributes to exercise intolerance and increased morbidity and mortality, yet the molecular mechanisms remain poorly understood. Therefore, we aimed to compare parameters of antioxidative capacity, energy metabolism, and catabolic/anabolic balance in diaphragm and quadriceps muscle in an animal model of CHF. Ligation of the left anterior descending coronary artery (n = 13) or sham operation (n = 11) was performed on Wistar Kyoto rats. After 12 weeks, echocardiography and invasive determination of maximal rates of left ventricular (LV) pressure change were performed. Antioxidative and metabolic enzyme activities and expression of catabolic/anabolic markers were assessed in quadriceps and diaphragm muscle. Ligated rats developed CHF (i.e. severe LV dilatation, reduced LV ejection fraction, and impaired maximal rates of LV pressure change; P < 0.001). There was a divergent response for antioxidant enzymes between the diaphragm and quadriceps in CHF rats, with glutathione peroxidase and manganese superoxide dismutase activity increased in the diaphragm but reduced in the quadriceps relative to shams (P < 0.01). Metabolic enzymes were unaltered in the diaphragm, but cytochrome c oxidase activity (P < 0.01) decreased and lactate dehydrogenase activity (P < 0.05) increased in the quadriceps of CHF animals. Protein expression of the E3 ligase muscle ring finger 1 and proteasome activity were increased (P < 0.05) in both the diaphragm and quadriceps in CHF rats compared with shams. Chronic heart failure induced divergent antioxidative and metabolic but similar catabolic responses between the diaphragm and quadriceps. Despite the quadriceps demonstrating significant impairments in CHF, apparent beneficial adaptations of an increased antioxidative capacity were induced in the diaphragm. Nevertheless, muscle ring finger 1 and proteasome activity (markers of protein

  15. Simultaneous Bilateral Quadriceps Tendon Rupture following Long-Term Low-Dose Nasal Corticosteroid Application

    PubMed Central

    Ettinger, Max; Krettek, Christian

    2013-01-01

    Simultaneous bilateral quadriceps tendon rupture is a very rare injury, which was previously only described in slightly more than 100 cases in the English literature. Occurrence after minor trauma is predominantly associated with certain medical conditions including chronic diseases and long-term use of certain drugs. We report the case of a 61-year-old healthy patient who sustained a simultaneous bilateral quadriceps tendon rupture following minor trauma. Medical history was completely clear except of a long-term nasal corticosteroid medication due to allergic rhinitis. PMID:23984143

  16. Impact of quadriceps strengthening on response to fatiguing exercise following ACL reconstruction.

    PubMed

    Kuenze, Christopher; Eltoukhy, Moataz; Kelly, Adam; Kim, Chang-Young

    2017-01-01

    Patients commonly experience altered response to fatiguing exercise after ACL reconstruction (ACLR). The objective of this study was to assess the impact of quadriceps strengthening on response to exercise after ACLR. Clinical trial. Ten participants with a history of primary, unilateral ACLR (sex=9F/1M, age=21.0±2.8 years, BMI=23.7±2.7kg/m(2)) and 10 healthy participants (sex=9F/1M, age=22.2±3.2 years, BMI=23.8±3.9kg/m(2)) participated. ACLR participants completed a 2-week quadriceps strengthening intervention including 14 progressive strengthening exercise sessions. Normalized knee extension maximum voluntary isometric contraction (MVIC) torque (Nm/kg) and quadriceps central activation ratio (%, CAR) were measured before and after a 30-minute fatiguing exercise protocol. ACLR participants completed testing before and after the 2-week intervention while control participants completed a single testing session. The intervention significantly improved normalized knee extension MVIC torque (pre-intervention=1.85±0.67Nm/kg, post-intervention=2.09±0.81Nm/kg, p=0.04) and quadriceps CAR in the ACLR involved limb (pre-intervention=86.51±5.03%, post-intervention=92.94±5.99%, p=0.02). Quadriceps CAR (pre-intervention=1.13±9.04%, post-intervention=-3.97±4.59%, p=0.16) and normalized knee extension MVIC torque (pre-intervention=0.26±20.90%, post-intervention=-8.02±12.82%, p=0.30) response to exercise did not significantly change from pre-intervention to post-intervention conditions. Two weeks of quadriceps strengthening reduced this between group difference in the involved limb which may indicate restoration of more optimal quadriceps neuromuscular function and increased demand on the quadriceps during physical activity. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  17. Effect of 8-week high-intensity stretching training on biceps femoris architecture.

    PubMed

    Freitas, Sandro R; Mil-Homens, Pedro

    2015-06-01

    Previous studies have reported no changes on muscle architecture (MA) after static stretching interventions; however, authors have argued that stretching duration and intensity may not have been sufficient. A high-intensity stretching intervention targeting the knee flexors with an 8-week duration was conducted to observe the effects on biceps femoris long head (BF) architecture. Participants (n = 5) performed an average of 3.1 assisted-stretching sessions per week, whereas a control group (n = 5) did not perform stretching. The knee extension passive maximal range of motion (ROM), and BF fascicle length (FL), fascicle angle, and muscle thickness were assessed before and after the intervention. A significant increase was observed for FL (+12.3 mm, p = 0.04) and maximal ROM (+14.2°, p = 0.04) for the stretching group after the intervention. No significant changes were observed for the control group in any parameter. An 8-week high-intensity stretching program was observed to efficiently increase the BF FL, as well as the knee extension maximal ROM. Stretching intensity and duration may play an important role on MA adaptation.

  18. DOES RECTUS FEMORIS TRANSFER INCREASE KNEE FLEXION DURING STANCE PHASE IN CEREBRAL PALSY?

    PubMed Central

    de Morais, Mauro César; Blumetti, Francesco Camara; Kawamura, Cátia Miyuki; Lopes, José Augusto Fernandes; Neves, Daniella Lins; Cardoso, Michelle de Oliveira

    2016-01-01

    ABSTRACT Objective: To evaluate whether distal rectus femoris transfer (DRFT) is related to postoperative increase of knee flexion during the stance phase in cerebral palsy (CP). Methods: The inclusion criteria were Gross Motor Function Classification System (GMFCS) levels I-III, kinematic criteria for stiff-knee gait at baseline, and individuals who underwent orthopaedic surgery and had gait analyses performed before and after intervention. The patients included were divided into the following two groups: NO-DRFT (133 patients), which included patients who underwent orthopaedic surgery without DRFT, and DRFT (83 patients), which included patients who underwent orthopaedic surgery that included DRFT. The primary outcome was to evaluate in each group if minimum knee flexion in stance phase (FMJFA) changed after treatment. Results: The mean FMJFA increased from 13.19° to 16.74° (p=0.003) and from 10.60° to 14.80° (p=0.001) in Groups NO-DRFT and DRFT, respectively. The post-operative FMJFA was similar between groups NO-DRFT and DRFT (p=0.534). The increase of FMJFA during the second exam (from 13.01° to 22.51°) was higher among the GMFCS III patients in the DRFT group (p<0.001). Conclusion: In this study, DRFT did not generate additional increase of knee flexion during stance phase when compared to the control group. Level of Evidence III, Retrospective Comparative Study. PMID:26997910

  19. Ultrasound Assessment of the Rectus Femoris Cross-Sectional Area: Subject Position Implications.

    PubMed

    Hacker, Eileen Danaher; Peters, Tara; Garkova, Miglena

    2016-09-01

    Ultrasonic measurement of the rectus femoris (RF) is a novel, proxy measure for muscle strength. The impact of hip flexion/head of bed positioning on RF cross-sectional area (CSA) has not been fully explored. This study describes and compares differences in RF CSA across four degrees of hip flexion. This repeated-measures, comparative study enrolled healthy, pre-menopausal women (n = 20). RF CSA of the dominant leg was measured using the SonoSite M-Turbo ultrasound system with the head of bed at 0°, 20°, 30°, and 60°. One-way repeated measures indicated significant differences in RF CSA, F(3, 17) = 14.18, p < .001, with variation in hip flexion/head of bed elevation and significant RF CSA differences between: (a) 0° and 20°, (b) 0° and 30°, (c) 0° and 60°, and (d) 20° and 60°. Standardizing patient positioning when conducting ultrasonic measurement of RF CSA is vital for researchers who assess muscle mass. © The Author(s) 2016.

  20. Is myoelectric activity distributed equally within the rectus femoris muscle during loaded, squat exercises?

    PubMed

    de Souza, Leonardo Mendes Leal; da Fonseca, Desirée Barros; Cabral, Hélio da Veiga; de Oliveira, Liliam Fernandes; Vieira, Taian Martins

    2017-04-01

    Recent evidence suggests different regions of the rectus femoris (RF) muscle respond differently to squat exercises. Such differential adaptation may result from neural inputs distributed locally within RF, as previously reported for isometric contractions, walking and in response to fatigue. Here we therefore investigate whether myoelectric activity distributes evenly within RF during squat. Surface electromyograms (EMGs) were sampled proximally and distally from RF with arrays of electrodes, while thirteen healthy volunteers performed 10 consecutive squats with 20% and 40% of their body weight. The root mean square (RMS) value, computed separately for thirds of the concentric and eccentric phases, was considered to assess the proximo-distal changes in EMG amplitude during squat. The channels with variations in EMG amplitude during squat associated with shifts in the muscle innervation zone were excluded from analysis. No significant differences were observed between RF regions when considering squat phases and knee joint angles individually (P>0.16) while a significant interaction between phase and knee joint angle with detection site was observed (P<0.005). For the two loads considered, proximal RMS values were greater during the eccentric phase and for the more flexed knee joint position (P<0.001). Our results suggest inferences on the degree of RF activation during squat must be made cautiously from surface EMGs. Of more practical relevance, there may be a potential for the differential adaption of RF proximal and distal regions to squat exercises.

  1. EMG amplitude of the biceps femoris during jumping compared to landing movements.

    PubMed

    Padulo, Johnny; Tiloca, Alessandra; Powell, Douglas; Granatelli, Giampietro; Bianco, Antonino; Paoli, Antonio

    2013-01-01

    Hamstrings injury is a common occurrence in athletic performance. These injuries tend to occur during a deceleration or landing task suggesting the negative work may be a key component in hamstrings injury. The purpose of this study was to investigate the muscular activity (EMG) of the biceps femoris (BF) in different phases (concentric vs. eccentric) of a Counter Movement Jump (CMJ), Squat Jump (SJ) and the Braking Phase (BP) of a landing task. Twelve female volleyball players performed 5 CMJs, SJs and BPs while surface EMG was recorded using a MuscleLab (BoscoSystem(TM), Norway). EMG values were normalized to an maximal voluntary contraction. A repeated measures analysis of variance (ANOVA) was used to compare mean normalized EMG values of the concentric and eccentric portions of the CMJ with the BP and SJ. The ANOVA revealed significantly lower BF activation in the concentric and eccentric portions of the CMJ compared to the BP (64%, p < 0.001) and SJ (7%, p = 0.02), respectively. These findings suggest that the CMJ relies on a greater contribution of elastic tissues during the concentric and eccentric portions of the movement and thus requires less muscle activation of the BF.

  2. Reliability of Sonographic Assessment of Biceps Femoris Distal Tendon Strain during Passive Stretching.

    PubMed

    Kellis, Eleftherios; Ellinoudis, Athanasios; Intziegianni, Konstantina

    2017-09-01

    The purpose of this study was to determine the intra-rater, inter-examiner and inter-observer reliability of biceps femoris long head (BFlh) tendon strain using ultrasound imaging. Nineteen patients (age: 20.4 ± 0.35 y) were tested twice with a 1-wk interval. Each session included passive stretching from three different hip positions. Tests were performed independently by two examiners while BFlh tendon displacement (mm) and strain (%) were manually extracted from ultrasound video footages by two observers. Intra-rater comparisons revealed an intra-class correlation coefficient (ICC2,1) range of 0.87 to 0.98 and a variability less than 4.74%. Inter-examiner comparisons revealed an ICC2,1 range of 0.83 to 0.99 and less than 4.69% variability. Inter-observer ICCs ranged from 0.93 to 0.97 with variability less than 4.89%. Using a well-defined scanning protocol, two experienced examiners attained high levels of intra-rater agreement, with similarly excellent results for inter-rater and inter-observer reliability for BFlh tendon displacement and strain. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  3. Age-related decrease of the phosphorus content in the ligamentum capitis femoris of monkeys.

    PubMed

    Tohno, Yoshiyuki; Tohno, Setsuko; Oishi, Takao; Minami, Takeshi; Khanpetch, Pongsak; Azuma, Cho; Quiggins, Ranida

    2014-10-01

    To elucidate compositional changes of the ligament with aging, the authors investigated age-related changes of elements in the ligamentum capitis femoris (LCF) of monkeys with a wide range of ages by direct chemical analysis. Used rhesus and Japanese monkeys consisted of 9 males and 22 females, ranging in age from newborn to 31 years (average age = 10.4 ± 10.9 years). After incineration with nitric acid and perchloric acid, element contents were determined by inductively coupled plasma-atomic emission spectrometry. It was found that the P content decreased significantly in the LCFs of monkeys with aging, but other six element contents, Ca, S, Mg, Zn, Fe, and Na, did not change significantly with aging. Assuming that the P content indicated the active cell density and the S content indicated the protein amount, an age-related change of the mass ratio of P/S was examined in the LCFs. The mass ratio of P/S decreased significantly in the LCFs in childhood. Regarding the relationships among elements, significant direct correlations were found among the Ca, P, S, and Mg contents in the LCFs. It was suggested that the active cell density of the connective tissue cells might decrease significantly in the LCF in childhood.

  4. Endoscopic Surgical Removal of Calcific Tendinitis of the Rectus Femoris: Surgical Technique

    PubMed Central

    Comba, Fernando; Piuzzi, Nicolás S.; Zanotti, Gerardo; Buttaro, Martín; Piccaluga, Francisco

    2015-01-01

    Calcific tendinitis of the rectus femoris (CTRF) is an under-recognized condition and, because of its self-limiting nature, is usually managed conservatively. Nevertheless, when nonsurgical therapy fails, further invasive alternatives are required. At this point, arthroscopic resection provides a minimally invasive and interesting alternative to open surgery. The aim of this work is to report the surgical technique of endoscopic surgical removal in patients with CTRF at the periarticular region of the hip joint. Endoscopic surgical removal of CTRF was performed without traction following anatomic landmarks for hip arthroscopy portal placement. We used the anterolateral portal and the proximal accessory portal to obtain access to the lesion. A shaver and radiofrequency device are useful tools to depict the calcific lesion while the whole resection is performed with a 5-mm round burr. Intraoperative fluoroscopy control during the entire procedure is essential. Endoscopic treatment of calcific tendinitis of the hip is a valuable technique in the treatment of patients who do not respond to conservative treatment. PMID:26759778

  5. Endoscopic Surgical Removal of Calcific Tendinitis of the Rectus Femoris: Surgical Technique.

    PubMed

    Comba, Fernando; Piuzzi, Nicolás S; Zanotti, Gerardo; Buttaro, Martín; Piccaluga, Francisco

    2015-08-01

    Calcific tendinitis of the rectus femoris (CTRF) is an under-recognized condition and, because of its self-limiting nature, is usually managed conservatively. Nevertheless, when nonsurgical therapy fails, further invasive alternatives are required. At this point, arthroscopic resection provides a minimally invasive and interesting alternative to open surgery. The aim of this work is to report the surgical technique of endoscopic surgical removal in patients with CTRF at the periarticular region of the hip joint. Endoscopic surgical removal of CTRF was performed without traction following anatomic landmarks for hip arthroscopy portal placement. We used the anterolateral portal and the proximal accessory portal to obtain access to the lesion. A shaver and radiofrequency device are useful tools to depict the calcific lesion while the whole resection is performed with a 5-mm round burr. Intraoperative fluoroscopy control during the entire procedure is essential. Endoscopic treatment of calcific tendinitis of the hip is a valuable technique in the treatment of patients who do not respond to conservative treatment.

  6. Biceps femoris and semitendinosus tendon/aponeurosis strain during passive and active (isometric) conditions.

    PubMed

    Kellis, Eleftherios

    2016-02-01

    The purpose of this study was to quantify strain and elongation of the long head of the biceps femoris (BFlh) and the semitendinosus (ST) tendon/aponeurosis. Forty participants performed passive knee extension trials from 90° of knee flexion to full extension (0°) followed by ramp isometric contractions of the knee flexors at 0°, 45° and 90° of knee flexion. Two ultrasound probes were used to visualize the displacement of BFlh and ST tendon/aponeurosis. Three-way analysis of variance designs indicated that: (a) Tendon/aponeurosis (passive) elongation and strain were higher for the BFlh than the ST as the knee was passively extended (p<0.05), (b) contraction at each angular position was accompanied by a smaller BFlh tendon/aponeurosis (active) strain and elongation than the ST at higher levels of effort (p<0.05) and (c) combined (passive and active) strain was significantly higher for the BFlh than ST during ramp contraction at 0° but the opposite was observed for the 45° and 90° flexion angle tests (p<0.05). Passive elongation of tendon/aponeurosis has an important effect on the tendon/aponeurosis behavior of the hamstrings and may contribute to a different loading of muscle fibers and tendinous tissue between BFlh and ST.

  7. The effectiveness of two novel techniques in establishing the mechanical and contractile responses of biceps femoris.

    PubMed

    Ditroilo, Massimiliano; Hunter, Angus M; Haslam, Samuel; De Vito, Giuseppe

    2011-08-01

    Portable tensiomyography (TMG) and myotonometry (MMT) devices have been developed to measure mechanical and contractile properties of skeletal muscle. The aim of this study was to explore the sensitivity of the aforementioned techniques in detecting a change in passive mechanical properties of the biceps femoris (BF) muscle as a result of change in knee joint angle (i.e. muscle length). BF responses were assessed in 16 young participants (23.4 ± 4.9 years), at three knee joint angles (0°, 45° and 90°), for maximal isometric torque (MIT) along with myo-electrical activity. Contractile and mechanical properties were measured in a relaxed state. Inter-day reliability of the TMG and MMT was also assessed. MIT changed significantly (p < 0.01) across the three angles, so did stiffness and other parameters measured with MMT (p < 0.01). Conversely, TMG could detect changes only at two knee angles (0° and 45°, p < 0.01), when there is enough tension in the muscle. Reliability was overall insufficient for TMG whilst absolute reliability was excellent (coefficient of variation < 5%) for MMT. The ability of MMT more than TMG to detect an inherent change in stiffness can be conceivably exploited in a number of clinical/therapeutic applications that have to do with unnatural changes in passive muscle stiffness.

  8. Effect of isokinetic training on quadriceps peak torgue in healthy subjects and patients with burn injury.

    PubMed

    Ahmed, Emad Tawfik; Abdel-aziem, Amr Almaz; Ebid, Anwar Abdelgayed

    2011-10-01

    To evaluate the improvement rate of quadriceps muscle peak torque in healthy subjects and patients with burn injuries after an isokinetic training programme. Thirty male volunteers, 15 healthy and 15 subjects with burn injury after complete healing, participated in the study. Concentric and eccentric torque of quadriceps was measured for both groups using an isokinetic dynamometer before and after 6 weeks of isokinetic training. The tests were performed at angular velocities of 30°/s and 90°/s. There was a significant increase in the quadricep speak torque for both groups at both angular velocities after isokinetic training. During eccentric contraction at angular velocities of 30°/s and 90°/s the percentage improvement in the burned group was higher than in the healthy group(p = 0.003 and p = 0.0008, respectively). During concentric contraction at an angular velocity of 30°/s the percentage improvement in the burned group was higher than the healthy group (p = 0.020). However, during concentric contraction at an angular velocity of 90°/s there was no significant difference between the groups (p = 0.742). The isokinetic training programme was effective in increasing the concentric and eccentric peak torque of the quadriceps muscle for healthy subjects and patients with burn injuries.

  9. Oxidative stress participates in quadriceps muscle dysfunction during the initiation of osteoarthritis in rats.

    PubMed

    Hsu, Dur-Zong; Chu, Pei-Yi; Wu, Po-Ting; Shen, Po-Chuan; Jou, I-Ming

    2015-01-01

    Osteoarthritis is the most common form of arthritis, affecting approximately 15% of the population. Quadriceps muscle weakness is one of the risk factors of osteoarthritis development. Oxidative stress has been reported to play an important role in the pathogenesis of various muscle dysfunction; however, whether it is involved in osteoarthritis-associated quadriceps muscle weakness has never been investigated. The aim of the present study is to examine the involvement of oxidative stress in quadriceps muscle dysfunction in the initiation of osteoarthritis in rats. Rat osteoarthritis was initiated by conducting meniscectomy (MNX). Quadriceps muscle dysfunction was evaluated by assessing muscular interleukin-6, citrate synthase activity, and myosin heavy chain IIa mRNA expression levels. Muscular oxidative stress was assessed by determining lipid peroxidation, Nrf2 expression, reactive oxygen species, and circulating antioxidants. Increased muscular interleukin-6 production as well as decreased citrate synthase activity and myosin heavy chain IIa mRNA expression were observed at 7 and 14 days after MNX. Biomarkers of oxidative stress were significantly increased after MNX. Muscular free radical counts were increased while glutathione and glutathione peroxidase expression were decreased in MNX-treated rats. We conclude that oxidative stress may be involved in the pathogenesis of muscle dysfunction in MNX-induced osteoarthritis.

  10. Fatigue effects on quadriceps and hamstrings activation in dancers performing drop landings.

    PubMed

    McEldowney, Kasey M; Hopper, Luke S; Etlin-Stein, Hannah; Redding, Emma

    2013-09-01

    Fatigue may reduce a dancer's ability to maintain the muscle synergies required for stable human movement. Therefore, fatigue presents as a potential risk factor for injury in dancers. Activation patterns of the quadriceps and hamstrings muscle groups in athletic populations have been consistently reported to alter in response to fatigue during landing tasks. It is unknown whether dancers demonstrate similar muscle activation patterns, nor if dancers respond to fatiguing protocols, with regard to muscle activation, in the same manner as their athletic counter-parts. The purpose of this study was to assess quadriceps and hamstrings activation levels in a cohort of dancers performing drop landings before and after completion of a dance-specific fatigue protocol, the High Intensity Dance Performance Fitness Test. Quadriceps and hamstrings co-contraction ratios significantly increased between pre- and post-fatigue conditions in a similar fashion to that reported in the literature. Therefore, the neuromuscular activation of the knee extensors and flexors in dancers changed in response to the dance-specific fatiguing protocol. Furthermore, quadriceps and hamstrings co-contraction ratios were substantially greater than previously reported in other athletic populations, due to low hamstrings activation levels. Future investigation of dancer biomechanical adaptations to fatigue would be beneficial to further examine the potential implications for injury risk.

  11. Treatment of Knee Osteoarthritis in Relation to Hamstring and Quadriceps Strength

    PubMed Central

    Hafez, Ashraf Ramadan; Al-Johani, Ahmed H.; Zakaria, Abdul Rahim; Al-Ahaideb, Abdulaziz; Buragadda, Syamala; Melam, Ganeswara Rao; Kachanathu, Shaji J.

    2013-01-01

    [Purpose] To assess the effect of hamstring and quadriceps strengthening exercises on pain intensity, gait velocity, maximum isometric strength, and activities of daily living of patients with knee osteoarthritis (OA). [Subjects and Methods] A total of 20 patients with knee OA, 50 to 65 years of age (57.65 ± 4.78 years), received hot packs, strengthening exercises for the quadriceps and the hamstring muscles and stretching exercises for hamstring muscles. Outcome measures included: the Western Ontario and McMaster Universities OA index questionnaire (WOMAC) scores for assessing health status and health outcomes of knee OA; self-reported pain intensity scores, measured using a visual analogue scale; the 50 ft walk test (a measure of gait velocity and function); and handheld dynamometry (a tool used to measure maximum isometric strength of knee extension and flexion). [Results] There was a significant difference between pre- and post-intervention measures of pain intensity, 50 ft walk times, hamstring strength, and quadriceps strength. Significant differences in WOMAC measures were also observed in the subscales of pain, stiffness and physical function, as well as WOMAC total scores. [Conclusion] Strengthening the hamstring muscles in addition to strengthening the quadriceps muscles proved to be beneficial for perceived knee pain, range of motion, and decreasing the limitation of functional performance of patients with knee OA. PMID:24396198

  12. Identifying Dosage Effect of Light-Emitting Diode Therapy on Muscular Fatigue in Quadriceps.

    PubMed

    Hemmings, Thomas J; Kendall, Kristina L; Dobson, John L

    2017-02-01

    Hemmings, TJ, Kendall, KL, and Dobson, JL. Identifying dosage effect of light-emitting diode therapy on muscular fatigue in quadriceps. J Strength Cond Res 31(2): 395-402, 2017-The purpose of this study was to compare the effects of various dosages of light-emitting diode therapy (LEDT) on muscle fatigue while performing a single-leg extension to exhaustion. A total of 34 recreationally resistance-trained athletes between the ages of 18 and 26 participated in 4 trials. Each trial included pre-exercise/postexercise blood lactate measurements and 2 sets of 3 maximal voluntary isometric contractions (MVICs), followed by LEDT on 6 points across the superficial quadriceps. Each randomized trial consisted of a placebo, 30, 60, or 120 seconds on each point on the quadriceps. Three minutes after LEDT, the participants performed an eccentric leg extension with 120% of MVIC until fatigue. There was significant increase in the number of repetitions performed between the placebo treatment and 60 seconds (p = 0.023), as well as placebo and 120 seconds (p = 0.004) of irradiation on each point. There were no significant differences in blood lactate levels between any of the 4 trials. In conclusion, LEDT had a positive effect on performance when irradiating 6 points on the superficial quadriceps for 60 and 120 seconds before an eccentric leg extension.

  13. Relationship between knee alignment and the electromyographic activity of quadriceps muscles in patients with knee osteoarthritis

    PubMed Central

    Lim, Seong Hoon; Hong, Bo Young; Oh, Jee Hae; Lee, Jong In

    2015-01-01

    [Purpose] We evaluated the relationship between knee alignment and the electromyographic (EMG) activity of the vastus medialis (VM) to the vastus lateralis (VL) muscles in patients with knee osteoarthritis (OA) in a cross-sectional study. [Subjects and Methods] Forty subjects with knee OA were assessed by anatomic radiographic knee alignment and the VM/VL ratio was calculated. Surface EMG from both the VM and VL muscles were evaluated during maximal isometric contraction at 60° knee flexion. Simultaneously, peak quadriceps torque was assessed using an isokinetic dynamometer. Subjects were categorized into low, moderate, and high varus groups according to knee malalignment. The peak quadriceps torque and VM/VL ratio across groups, and their relationships with varus malalignment were analyzed. [Results] All subjects had medial compartment OA and the VM/VL ratio of all subjects was 1.31 ± 0.28 (mean ± SD). There were no significant differences in the peak quadriceps torque or VM/VL ratios across the groups nor were there any significant relationships with varus malalignment. [Conclusion] The VM/VL ratio and peak quadriceps torque were not associated with the severity of knee varus malalignment. PMID:25995602

  14. [Lewis-Sumner syndrome presenting unilateral quadriceps amyotrophy as an initial symptom].

    PubMed

    Fujiyama, J; Aita, T; Itoh, K; Hamano, T; Kumano, T; Kinomoto, K; Fujii, A; Yasokawa, T; Kuriyama, M

    2000-11-01

    We report a 55-year-old man with a chief complaint of wasting and weakness of the left quadriceps muscle. At age 54, he noticed difficulty in running and weakness in the left thigh, which gradually progressed. On the first admission to our hospital, based on the nerve conduction studies (NCS), the muscle biopsy findings showing neurologenic changes, and no abnormality of spinal MRI, we diagnosed as unilateral quadriceps amyotrophy, which resulted from an atypical form of spinal progressive muscular atrophy. One year later, he showed the bilateral hand weakness, conduction blocks on the right median and ulnar nerves by NCS, and the presence of serum anti-GM 1 antibody. From these findings, Lewis-Sumner syndrome was diagnosed. The therapy of high-dose intravenous immunoglobulin moderately improved his symptoms. The clinical symptoms of quadriceps amyotrophy is produced by various disorders including spinal progressive muscular atrophy, spinal extradural arachnoid cyst, rimmed vacuole myopathy, Becker dystrophy, limb-girdle dystrophy, and focal myositis. However, there have been no reports of a case of Lewis-Sumner syndrome. It is important to consider Lewis-Sumner syndrome in the differential diagnosis of quadriceps amyotrophy.

  15. The evaluation of muscle recovery after anatomical single-bundle ACL reconstruction using a quadriceps autograft.

    PubMed

    Iriuchishima, Takanori; Ryu, Keinosuke; Okano, Tatsumasa; Suruga, Makoto; Aizawa, Shin; Fu, Freddie H

    2017-05-01

    The purpose of this study was to reveal the degree of muscle recovery and report the clinical results of anatomical single-bundle ACL reconstruction using a quadriceps autograft. Twenty subjects undergoing anatomical single-bundle ACL reconstruction using a quadriceps autograft were included in this study. A 5-mm-wide, 8-cm-long graft, involving the entire layer of the quadriceps tendon, was harvested without bone block. The average graft diameter was 8.1 ± 1.4 mm. An initial tension of 30 N was applied. The femoral tunnel was created from the far-medial portal. Each femoral and tibial tunnel was created close to the antero-medial bundle insertion site. For the evaluation of muscle recovery (quadriceps and hamstring), a handheld dynamometer was used. The evaluation of muscle recovery was performed pre-operatively, and at 3, 6, 9, and 12 months after surgery. Muscle recovery data were calculated as a percentage of leg strength in the non-operated leg. Anterior tibial translation (ATT), pivot shift test, and IKDC score were evaluated. The average quadriceps strength pre-operatively, and at 3, 6, 9, and 12 months after ACL reconstruction was 90.5 ± 19, 67.8 ± 21.4, 84 ± 17.5, and 85.1 ± 12.6 %, respectively. The average hamstring strength pre-operatively, and at 3, 6, 9, and 12 months after ACL reconstruction was 99.5 ± 13.7, 78.7 ± 11.4, 90.5 ± 19, and 96.7 ± 13.8 %, respectively. ATT pre-operatively and at 12 months after surgery was 5.4 ± 1.3 and 1.0 ± 0.8 mm, respectively. No subjects exhibited positive pivot shift after surgery. Within 6 months following surgery, quadriceps hypotrophy was observed in all subjects. However, the hypotrophy had recovered at 12 months following surgery. No subjects complained of donor site pain after surgery. Anatomical single-bundle ACL reconstruction using a quadriceps autograft resulted in equivalent level of muscle recovery and knee stability when compared with previously reported ACL

  16. Biceps Femoris Aponeurosis Size: A Potential Risk Factor for Strain Injury?

    PubMed

    Evangelidis, Pavlos E; Massey, Garry J; Pain, Matthew T G; Folland, Jonathan P

    2015-07-01

    A disproportionately small biceps femoris long head (BFlh) proximal aponeurosis has been suggested as a risk factor for hamstring strain injury by concentrating mechanical strain on the surrounding muscle tissue. However, the size of the BFlh aponeurosis relative to BFlh muscle size, or overall knee flexor strength, has not been investigated. This study aimed to examine the relationship of BFlh proximal aponeurosis area with muscle size (maximal anatomical cross-sectional area (ACSAmax)) and knee flexor strength (isometric and eccentric). Magnetic resonance images of the dominant thigh of 30 healthy young males were analyzed to measure BFlh proximal aponeurosis area and muscle ACSAmax. Participants performed maximum voluntary contractions to assess knee flexion maximal isometric and eccentric torque (at 50° s and 350° s). BFlh proximal aponeurosis area varied considerably between participants (more than fourfold, range = 7.5-33.5 cm, mean = 20.4 ± 5.4 cm, coefficient of variation = 26.6%) and was not related to BFlh ACSAmax (r = 0.04, P = 0.83). Consequently, the aponeurosis/muscle area ratio (defined as BFlh proximal aponeurosis area divided by BFlh ACSAmax) exhibited sixfold variability, being 83% smaller in one individual than another (0.53 to 3.09, coefficient of variation = 32.5%). Moreover, aponeurosis size was not related to isometric (r = 0.28, P = 0.13) or eccentric knee flexion strength (r = 0.24, P ≥ 0.20). BFlh proximal aponeurosis size exhibits high variability between healthy young men, and it was not related to BFlh muscle size or knee flexor strength. Individuals with a relatively small aponeurosis may be at increased risk of hamstring strain injury.

  17. Anatomy of the long head of biceps femoris: An ultrasound study.

    PubMed

    Tosovic, D; Muirhead, J C; Brown, J M M; Woodley, S J

    2016-09-01

    Hamstring strains, particularly involving the long head of biceps femoris (BFlh) at the proximal musculotendinous junction (MTJ), are commonly experienced by athletes. With the use of diagnostic ultrasound increasing, an in-depth knowledge of normal ultrasonographic anatomy is fundamental to better understanding hamstring strain. The aim of this study was to describe the architecture of BFlh, using ultrasonography, in young men and cadaver specimens. BFlh morphology was examined in 19 healthy male participants (mean age 21.6 years) using ultrasound. Muscle, tendon and MTJ lengths were recorded and architectural parameters assessed at four standardised points along the muscle. Measurement accuracy was validated by ultrasound and dissection of BFlh in six male cadaver lower limbs (mean age 76 years). Intra-rater reliability of architectural parameters was examined for repeat scans, image analysis and dissection measurements. Distally the BFlh muscle had significantly (P < 0.05) shorter fascicles and larger pennation angles than proximal sites. Agreement between ultrasound and dissection (cadaver study) was excellent for all architectural parameters, except pennation angle (PA), and MTJ length. All other measures demonstrated good-excellent repeatability. BFlh is not uniform in architecture when imaged using ultrasound. It is likely that its distal-most segment is better suited for force production in comparison to the more proximal segments, which show excursive potential, traits which possibly contribute to the high rate of injury at the proximal MTJ. The data presented in this study provide specific knowledge of the normal ultrasonographic anatomy of BFlh, which should be of assistance in analysing BFlh injury via imaging. Clin. Anat. 29:738-745, 2016. © 2016 Wiley Periodicals, Inc.

  18. Architectural Changes of the Biceps Femoris Long Head after Concentric or Eccentric Training.

    PubMed

    Timmins, Ryan G; Ruddy, Joshua D; Presland, Joel; Maniar, Nirav; Shield, Anthony J; Williams, Morgan D; Opar, David A

    2016-03-01

    To determine the architectural adaptations of the biceps femoris long head (BFlh) after concentric or eccentric strength training interventions and the time course of adaptation during training and detraining. Participants in this intervention (concentric training group [n = 14], eccentric training group [n = 14], male subjects) completed a 4-wk control period, followed by 6 wk of either concentric- or eccentric-only knee flexor training on an isokinetic dynamometer and finished with 28 d of detraining. Architectural characteristics of BFlh were assessed at rest and during graded isometric contractions using two-dimensional ultrasonography at 28 d prebaseline; baseline; and days 14, 21, and 42 of the intervention and then again after 28 d of detraining. BFlh fascicle length was significantly longer in the eccentric training group (P < 0.05; d range, 2.65-2.98) and shorter in the concentric training group (P < 0.05; d range, -1.62 to -0.96) after 42 d of training compared with baseline at all isometric contraction intensities. After the 28-d detraining period, BFlh fascicle length was significantly reduced in the eccentric training group at all contraction intensities compared with the end of the intervention (P < 0.05; d range, -1.73 to -1.55). There was no significant change in fascicle length of the concentric training group after the detraining period. These results provide evidence that short-term resistance training can lead to architectural alterations in the BFlh. In addition, the eccentric training-induced lengthening of BFlh fascicle length was reversed and returned to baseline values after 28 d of detraining. The contraction mode specific adaptations in this study may have implications for injury prevention and rehabilitation.

  19. Changes in muscle architecture of biceps femoris induced by eccentric strength training with nordic hamstring exercise.

    PubMed

    Alonso-Fernandez, D; Docampo-Blanco, P; Martinez-Fernandez, J

    2017-03-17

    Eccentric strength training alters muscle architecture, but it is also an important factor for the prevention of hamstring injuries. The purpose was to determine the architectural adaptations of the biceps femoris long head (BFlh) after eccentric strength training with nordic hamstring exercise (NHE), followed by a subsequent detraining period. The participants in this intervention (n=23) completed a period of 13 weeks consisting of a first week of control and prior training, followed by 8 weeks of eccentric strength training with NHE, and concluding with a 4-week period of detraining. The architectural characteristics of the BFlh were measured at rest using two-dimensional ultrasound before (M1-week 1) and after (M2-week 9) the eccentric strength training, and at the end of the detraining period (M3-week 13). The muscle fascicle length significantly increased (t=-7.73, d=2.28, P<.001) in M2 compared to M1, as well as the muscle thickness (t=-5.23, d=1.54, P<.001), while the pennation angle presented a significant decrease (t=7.81, d=2.3, P<.001). The muscle fascicle length decreased significantly (t=6.07, d=1.79, P<.001) in M3 compared to M2, while the pennation angle showed a significant increase (t=-4.63, d=1.36, P<.001). The results provide evidence that NHE may cause alterations in the architectural conditions of the BFlh and may have practical implications for injury prevention and rehabilitation programs. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Biceps Femoris Architecture and Strength in Athletes with a Previous Anterior Cruciate Ligament Reconstruction.

    PubMed

    Timmins, Ryan G; Bourne, Matthew N; Shield, Anthony J; Williams, Morgan D; Lorenzen, Christian; Opar, David A

    2016-03-01

    This study aimed to determine whether limbs with a history of anterior cruciate ligament (ACL) injury reconstructed from the semitendinosus display different biceps femoris long head (BFlh) architecture and eccentric strength, assessed during the Nordic hamstring exercise, compared with the contralateral uninjured limb. The architectural characteristics of the BFlh were assessed at rest and at 25% of a maximal voluntary isometric contraction (MVIC) in the control group (n = 52) and in the group who had previous ACL injury (n = 15) using two-dimensional ultrasonography. Eccentric knee flexor strength was assessed during the Nordic hamstring exercise. Fascicle length was shorter (P = 0.001; d range, 0.90-1.31) and pennation angle (P range, 0.001-0.006; d range, 0.87-0.93) was greater in the BFlh of the ACL-injured limb compared with those in the contralateral uninjured limb at rest and during a 25% MVIC. Eccentric strength was lower in the ACL-injured limb when compared with the contralateral uninjured limb. Fascicle length, MVIC, and eccentric strength were not different between the left and right limb in the control group. Limbs with a history of ACL injury reconstructed from the semitendinosus have shorter fascicles and greater pennation angles in the BFlh compared with those of the contralateral uninjured side. Eccentric strength during the Nordic hamstring exercise of the ACL-injured limb is significantly lower than that of the contralateral side. These findings have implications for ACL rehabilitation and hamstring injury prevention practices, which should consider altered architectural characteristics.

  1. Accuracy assessment of CKC high-density surface EMG decomposition in biceps femoris muscle

    NASA Astrophysics Data System (ADS)

    Marateb, H. R.; McGill, K. C.; Holobar, A.; Lateva, Z. C.; Mansourian, M.; Merletti, R.

    2011-10-01

    The aim of this study was to assess the accuracy of the convolution kernel compensation (CKC) method in decomposing high-density surface EMG (HDsEMG) signals from the pennate biceps femoris long-head muscle. Although the CKC method has already been thoroughly assessed in parallel-fibered muscles, there are several factors that could hinder its performance in pennate muscles. Namely, HDsEMG signals from pennate and parallel-fibered muscles differ considerably in terms of the number of detectable motor units (MUs) and the spatial distribution of the motor-unit action potentials (MUAPs). In this study, monopolar surface EMG signals were recorded from five normal subjects during low-force voluntary isometric contractions using a 92-channel electrode grid with 8 mm inter-electrode distances. Intramuscular EMG (iEMG) signals were recorded concurrently using monopolar needles. The HDsEMG and iEMG signals were independently decomposed into MUAP trains, and the iEMG results were verified using a rigorous a posteriori statistical analysis. HDsEMG decomposition identified from 2 to 30 MUAP trains per contraction. 3 ± 2 of these trains were also reliably detected by iEMG decomposition. The measured CKC decomposition accuracy of these common trains over a selected 10 s interval was 91.5 ± 5.8%. The other trains were not assessed. The significant factors that affected CKC decomposition accuracy were the number of HDsEMG channels that were free of technical artifact and the distinguishability of the MUAPs in the HDsEMG signal (P < 0.05). These results show that the CKC method reliably identifies at least a subset of MUAP trains in HDsEMG signals from low force contractions in pennate muscles.

  2. Biceps femoris long head architecture: a reliability and retrospective injury study.

    PubMed

    Timmins, Ryan G; Shield, Anthony J; Williams, Morgan D; Lorenzen, Christian; Opar, David A

    2015-05-01

    This study aimed (i) to determine the reliability of two-dimensional ultrasonography for the assessment of biceps femoris long head (BFlh) architectural characteristics and (ii) to determine whether limbs with a history of strain injury in the BFlh display different architecture and eccentric strength compared to uninjured limbs. This case-control study (control [n = 20], injured group [n = 16], males) assessed the BFlh architecture at rest and during graded isometric contractions using two-dimensional ultrasonography. The control group were assessed three times (>24 h apart) to determine reliability. Previously injured individuals were evaluated once. The assessment of BFlh architecture was highly reliable (intraclass correlations >0.90). Fascicle length (P < 0.001; d range = 0.67-1.34) and fascicle length relative to muscle thickness (P < 0.001; d range = 0.58-0.85) of the previously injured BFlh were significantly less than the contralateral uninjured BFlh at all intensities. Pennation angle of the previously injured BFlh was significantly greater (P < 0.001; d range = 0.62-0.88) than the contralateral uninjured BFlh at all intensities. Eccentric strength in the previously injured limb was significantly lower than that in the contralateral limb (-15.4%; -52.5 N, 95% confidence interval = -76.2 to -28.4; P < 0.001, d = 0.56). These data indicate that two-dimensional ultrasonography is reliable for assessing BFlh architecture at rest and during graded isometric contractions. Fascicle length, fascicle length relative to muscle thickness, and pennation angle are significantly different in previously injured BFlh compared to an uninjured contralateral BFlh. Eccentric strength of the previously injured limb is also significantly lower than that of the uninjured contralateral limb. These findings have implications for rehabilitation and injury prevention practices, which should consider altered architectural characteristics.

  3. Measurement of rectus femoris muscle velocities during patellar tendon jerk using vector tissue doppler imaging.

    PubMed

    Sikdar, Siddhartha; Lebiedowska, Maria; Eranki, Avinash; Garmirian, Lindsay; Damiano, Diane

    2009-01-01

    We have developed a vector tissue Doppler imaging (TDI) system based on a clinical scanner that can be used to measure muscle velocities independent of the direction of motion. This method overcomes the limitations of conventional Doppler ultrasound, which can only measure velocity components along the ultrasound beam. In this study, we utilized this method to investigate the rectus femoris muscle velocities during a patellar tendon jerk test. Our goal was to investigate whether the muscle elongation velocities during a brisk tendon tap fall within the normal range of velocities that are expected due to rapid stretch of limb segments. In a preliminary study, we recruited six healthy volunteers (three men and three women) following informed consent. The stretch reflex response to tendon tap was evaluated by measuring: (1) the tapping force using an accelerometer instrumented to the neurological hammer (2) the angular velocities of the knee extension and flexion using a electrogoniometer (3) reflex activation using electromyography (EMG) and (4) muscle elongation, extension and flexion velocities using vector TDI. The passive joint angular velocity was linearly related to the passive muscle elongation velocity (R(2)=0.88). The maximum estimated joint angular velocity corresponding to muscle elongation due to tendon tap was less than 8.25 radians/s. This preliminary study demonstrates the feasibility of vector TDI for measuring longitudinal muscle velocities and indicates that the muscle elongation velocities during a clinical tendon tap test are within the normal range of values for rapid limb stretch encountered in daily life. With further refinement, vector TDI could become a powerful method for quantitative evaluation of muscle motion in musculoskeletal disorders.

  4. Short-latency crossed responses in the human biceps femoris muscle

    PubMed Central

    Stevenson, Andrew J T; Kamavuako, Ernest N; Geertsen, Svend S; Farina, Dario; Mrachacz-Kersting, Natalie

    2015-01-01

    Interlimb reflexes contribute to the central neural co-ordination between different limbs in both humans and animals. Although commissural interneurons have only been directly identified in animals, spinally-mediated interlimb reflexes have been discovered in a number of human lower limb muscles, indicating their existence in humans. The present study aimed to investigate whether short-latency crossed-spinal reflexes are present in the contralateral biceps femoris (cBF) muscle following ipsilateral knee (iKnee) joint rotations during a sitting task, where participants maintained a slight pre-contraction in the cBF. Following iKnee extension joint rotations, an inhibitory reflex was observed in the surface electromyographic (EMG) activity of the cBF, whereas a facilitatory reflex was observed in the cBF following iKnee flexion joint rotations. The onset latency of both cBF reflexes was 44 ms, which is too fast for a transcortical pathway to contribute. The cBF inhibitory and facilitatory reflexes followed the automatic gain control principle, with the size of the response increasing as the level of background pre-contraction in the cBF muscle increased. In addition to the surface EMG, both short-latency inhibitory and facilitatory cBF reflexes were recorded directly at the motor unit level by i.m. EMG, and the same population of cBF motor units that were inhibited following iKnee extension joint rotations were facilitated following iKnee flexion joint rotations. Therefore, parallel interneuronal pathways (probably involving commissural interneurons) from ipsilateral afferents to common motoneurons in the contralateral leg can probably explain the perturbation direction-dependent reversal in the sign of the short-latency cBF reflex. PMID:25970767

  5. The effects of ACL injury on quadriceps and hamstring torque, work and power.

    PubMed

    Pincivero, Danny M; Heller, Brandan M; Hou, Su-I

    2002-09-01

    The aim of this study was to assess isokinetic torque, work and power between non-injured, ACL (anterior cruciate ligament)-deficient and ACL-reconstructed individuals. Ten healthy, non-injured individuals, seven unilateral ACL-deficient individuals and six unilateral ACL-reconstructed individuals were assessed for isokinetic quadriceps and hamstring strength at 1.05 and 3.14 rad.s-1. Peak torque, total work, average power and the ratio of peak torque to body mass were computed for both velocities. Peak torque was also corrected for body mass, using allometric modelling. The non-injured individuals showed significantly greater quadriceps peak torque to body mass ratios than the ACL-deficient and ACL-reconstructed individuals at both velocities, and greater hamstring peak torque to body mass ratios than the ACL-deficient group at 3.14 rad.s-1 (P < 0.05). The ACL-deficient individuals displayed greater quadriceps and hamstring peak torque, total work and average power than the non-injured individuals at 1.05 rad.s-1 (P < 0.05). The ACL-deficient individuals also displayed significantly greater peak torque, total work and average power than the ACL-reconstructed individuals for the quadriceps at both velocities (P < 0.05). The ACL-deficient individuals demonstrated greater hamstring peak torque and total work than the non-injured individuals at both velocities (P < 0.05). The allometrically modelled peak torques at both isokinetic velocities demonstrated that the quadriceps muscle values were significantly higher in the non-involved than the involved limb. The hamstring peak torques corrected for body mass were significantly higher in the non-involved than the involved limb only at 1.05 rad.s-1. The main finding from the present study is that isokinetic measures in ratio-scaled or absolute units yield a different outcome and, hence, interpretation compared with the allometric approach.

  6. Quadriceps Muscle Function After Rehabilitation With Cryotherapy in Patients With Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Hart, Joseph M.; Kuenze, Christopher M.; Diduch, David R.; Ingersoll, Christopher D.

    2014-01-01

    Context: Persistent muscle weakness after anterior cruciate ligament (ACL) reconstruction may be due to underlying activation failure and arthrogenic muscle inhibition (AMI). Knee-joint cryotherapy has been shown to improve quadriceps function transiently in those with AMI, thereby providing an opportunity to improve quadriceps muscle activation and strength in patients with a reconstructed ACL. Objective: To compare quadriceps muscle function in patients with a reconstructed ACL who completed a 2-week intervention including daily cryotherapy (ice bag), daily exercises, or both. Design: Cross-sectional study. Setting: Laboratory. Patients or Other Participants: A total of 30 patients with reconstructed ACLs who were at least 6 months post-index surgery and had measurable quadriceps AMI. Intervention(s): The patients attended 4 supervised visits over a 2-week period. They were randomly assigned to receive 20 minutes of knee-joint cryotherapy, 1 hour of therapeutic rehabilitation exercises, or cryotherapy followed by exercises. Main Outcome Measure(s): We measured quadriceps Hoffmann reflex, normalized maximal voluntary isometric contraction torque, central activation ratio using the superimposed-burst technique, and patient-reported outcomes before and after the intervention period. Results: After the 2-week intervention period, patients who performed rehabilitation exercises immediately after cryotherapy had higher normalized maximal voluntary isometric contraction torques (P = .002, Cohen d effect size = 1.4) compared with those who received cryotherapy alone (P = .16, d = 0.58) or performed exercise alone (P = .16, d = 0.30). Conclusions: After ACL reconstruction, patients with AMI who performed rehabilitation exercises immediately after cryotherapy experienced greater strength gains than those who performed cryotherapy or exercises alone. PMID:25299442

  7. Pain level after ACL reconstruction: A comparative study between free quadriceps tendon and hamstring tendons autografts.

    PubMed

    Buescu, Cristian Tudor; Onutu, Adela Hilda; Lucaciu, Dan Osvald; Todor, Adrian

    2017-03-01

    The objective of this study was to compare the pain levels and analgesic consumption after single bundle ACL reconstruction with free quadriceps tendon autograft versus hamstring tendon autograft. A total of 48 patients scheduled for anatomic single-bundle ACL reconstruction were randomized into two groups: the free quadriceps tendon autograft group (24 patients) and the hamstring tendons autograft group (24 patients). A basic multimodal analgesic postoperative program was used for all patients and rescue analgesia was provided with tramadol, at pain scores over 30 on the Visual Analog Scale. The time to the first rescue analgesic, the number of doses of tramadol and pain scores were recorded. The results within the same group were compared with the Wilcoxon signed test. Supplementary analgesic drug administration proved significantly higher in the group of subjects with hamstring grafts, with a median (interquartile range) of 1 (1.3) dose, compared to the group of subjects treated with a quadriceps graft, median = 0.5 (0.1.25) (p = 0.009). A significantly higher number of subjects with a quadriceps graft did not require any supplementary analgesic drug (50%) as compared with subjects with hamstring graft (13%; Z-statistics = 3.01, p = 0.002). The percentage of subjects who required a supplementary analgesic drug was 38% higher in the HT group compared with the FQT group. The use of the free quadriceps tendon autograft for ACL reconstruction leads to less pain and analgesic consumption in the immediate postoperative period compared with the use of hamstrings autograft. Level I Therapeutic study. Copyright © 2017 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

  8. Quadriceps Weakness, Patella Alta and Structural Features of Patellofemoral Osteoarthritis: The Multicenter Osteoarthritis Study

    PubMed Central

    Stefanik, Joshua J.; Guermazi, Ali; Zhu, Yanyan; Zumwalt, Ann C.; Gross, K. Douglas; Clancy, Margaret; Lynch, John A.; Segal, Neil A.; Lewis, Cora E.; Roemer, Frank W.; Powers, Christopher M.; Felson, David T.

    2011-01-01

    Objective To determine the relationship between quadriceps weakness and cartilage damage and bone marrow lesions (BMLs) in the patellofemoral joint (PFJ), and if this relationship is modified by patella alta. Methods The Multicenter Osteoarthritis (MOST) Study is a cohort study of persons aged 50–79 years with or at risk for knee OA. Concentric knee extensor strength was measured using an isokinetic dynamometer. Patella alta was measured using the Insall-Salvati ratio (ISR) on the lateral radiograph, and cartilage damage and bone marrow lesions (BMLs) were graded on MRI in the PFJ. We determined the association between quadriceps weakness with cartilage damage and BMLs in the PFJ among those knees with (ISR≥1.2) and without patella alta (ISR<1.2) using multiple binomial regression. Results 807 knees were studied (mean age 62 years, BMI 30, ISR 1.10), 64% from female subjects. Compared with knees in the highest strength tertile, those in the lowest had 10.2% {95% Confidence Interval (CI) 3–18}, 9.1% (95% CI 2–16), and 7.1% (95% CI 1–13) higher prevalence of lateral PFJ cartilage damage, medial PFJ cartilage damage, and lateral PFJ BMLs, respectively. The association between quadriceps weakness with cartilage damage and BMLs was not different between knees with and with out patella alta in the lateral PFJ. Conclusion Quadriceps weakness was associated with PFJ cartilage damage and BMLs. While both patella alta and quadriceps weakness are associated with PFJ damage, the combination of the two was not associated with more damage than either of these factors alone. PMID:21702087

  9. The use of dielectric properties and other physical analyses for assessing protein denaturation in beef biceps femoris muscle during cooking from 5 to 85°C.

    PubMed

    Brunton, N P; Lyng, J G; Zhang, L; Jacquier, J C

    2006-02-01

    Dielectric properties of beef biceps femoris muscle were recorded during heating (5-85°C) to assess their linkage to phase changes monitored by differential scanning calorimetry (DSC) and rheology. DSC indicated endotherms between 56 and 81°C corresponding to denaturation of actin, collagen and myosin. Matching changes in dielectric properties (dielectric constant (ε') and loss factor (ε″)) were noted at radio and/or microwave frequencies though the nature of the change differed depending upon frequency. The main observation in ε' was an increase above 65-66°C, most likely due to fluid release on collagen denaturation. This fluid plus liquid from myosin denaturation most likely solvated ions freed during myosin denaturation which manifested as an ε″ increase. However, it must be noted that meat structural protein denaturation is compounded with physical shrinkage which can also influence dielectric properties. Rheological parameters of beef muscle heated from 5 to 85°C also displayed marked changes relating to structural protein denaturation.

  10. Comparison of quadriceps strength and handgrip strength in their association with health outcomes in older adults in primary care.

    PubMed

    Chan, On Ying A; van Houwelingen, Anne H; Gussekloo, Jacobijn; Blom, Jeanet W; den Elzen, Wendy P J

    2014-01-01

    Sarcopenia is thought to play a major role in the functional impairment that occurs with old age. In clinical practice, sarcopenia is often determined by measuring handgrip strength. Here, we compared the lower limb quadriceps strength to the handgrip strength in their association with health outcomes in older adults in primary care. Our study population consisted of older adults (n = 764, 68.2% women, median age 83) that participated in the Integrated Systemic Care for Older People (ISCOPE) study. Participants were visited at baseline to measure quadriceps strength and handgrip strength. Data on health outcomes were obtained at baseline and after 12 months (including life satisfaction, disability in daily living, GP contact-time and hospitalization). Quadriceps strength and handgrip strength showed a weak association (β = 0.42 [95% CI 0.33-0.50]; R (2) = 0.17). Quadriceps strength and handgrip strength were independently associated with health outcomes at baseline, including quality of life, disability in daily living, GP contact-time, hospitalization, and gait speed. Combined weakness of the quadriceps and handgrip distinguished a most vulnerable subpopulation that presented with the poorest health outcomes. At follow-up, handgrip strength showed an association with quality of life (β = 0.05; P = 0.002) and disability in daily living (β = -0.5; P = 0.004). Quadriceps weakness did not further contribute to the prediction of the measured health outcomes. We conclude that quadriceps strength is only moderately associated with handgrip strength in an older population and that the combination of quadriceps strength and handgrip strength measurements may aid in the identification of older adults in primary care with the poorest health outcomes. In the prediction of poor health outcomes, quadriceps strength measurements do not show an added value to the handgrip strength.

  11. Are knee kinematic anomalies in swing due to rectus femoris spasticity different from those due to femoral anteversion in children with cerebral palsy? A quantitative evaluation using 3D gait analysis.

    PubMed

    Cimolin, Veronica; Piccinini, Luigi; Turconi, Anna Carla; Crivellini, Marcello; Galli, Manuela

    2010-05-01

    Quantitative comparison of gait strategy between stiff knee gait caused by rectus femoris spasticity versus that caused by femoral anteversion was the objective of this study. Twenty-three diplegic were divided into group 1 (excessive femoral anteversion without rectus femoris spasticity) and group 2 (normal femoral anteversion and rectus femoris spasticity). Both groups showed low knee flexion during swing (KMSw), but although group 1 exhibited normal KMSw timing and high hip intrarotation, group 2 presented delayed KMSw timing, with normal hip rotation. Reduced KMSw may be because of two different conditions: excessive femoral anteversion, leading only to KMSw reduction, and rectus femoris spasticity, inducing coexistence of reduced KMSw and its delayed timing.

  12. Fixed foot balance training increases rectus femoris activation during landing and jump height in recreationally active women.

    PubMed

    Kean, Crystal O; Behm, David G; Young, Warren B

    2006-01-01

    The objective of this study was to determine the effects of fixed foot and functionally directed balance training on static balance time, muscle activation during landing, vertical jump height and sprint time. Twenty-four recreationally active females were tested pre- and post-training (fixed foot balance training, n= 11, functionally directed balance training, n = 7 and control group, n = 6). Experimental subjects completed either fixed foot or functionally directed balance exercises 4 times/week for 6 weeks. Surface electromyography (EMG) was used to assess preparatory and reactive muscle activity of the rectus femoris (RF), biceps femoris (BF), and the soleus during one- and two-foot landings following a jump. Maximum vertical jump height, static balance and 20-meter sprint times were also examined. The fixed foot balance-training group showed a 33% improvement (p < 0.05) in static balance time and 9% improvement in jump height. Neither type of training improved sprint times. Further analysis revealed significant (p < 0.05) overall (data collapsed over groups and legs) increases in reactive RF activity when landing. Independently, the fixed foot balance group showed a 33% increase in reactive RF activity (p < 0.01). Overall, there was also significantly less reactive co-activation following training (p < 0.05). It appears that fixed foot balance training for recreationally active women may provide greater RF activity when landing and increased countermovement jump height. Key pointsBalance training increased rectus femoris EMG activity upon landing from a stride.Fixed foot balance training improved countermovement jump height.Neither fixed foot nor functionally directed balance training elicited changes in sprint times.

  13. Knee flexor strength and bicep femoris electromyographical activity is lower in previously strained hamstrings.

    PubMed

    Opar, David A; Williams, Morgan D; Timmins, Ryan G; Dear, Nuala M; Shield, Anthony J

    2013-06-01

    The aim of this study was to determine if athletes with a history of hamstring strain injury display lower levels of surface EMG (sEMG) activity and median power frequency in the previously injured hamstring muscle during maximal voluntary contractions. Recreational athletes were recruited, 13 with a history of unilateral hamstring strain injury and 15 without prior injury. All athletes undertook isokinetic dynamometry testing of the knee flexors and sEMG assessment of the biceps femoris long head (BF) and medial hamstrings (MHs) during concentric and eccentric contractions at ±180 and ±60°s(-1). The knee flexors on the previously injured limb were weaker at all contraction speeds compared to the uninjured limb (+180°s(-1)p=0.0036; +60°s(-1)p=0.0013; -60°s(-1)p=0.0007; -180°s(-1)p=0.0007) whilst sEMG activity was only lower in the BF during eccentric contractions (-60°s(-1)p=0.0025; -180°s(-1)p=0.0003). There were no between limb differences in MH sEMG activity or median power frequency from either BF or MH in the injured group. The uninjured group showed no between limb differences in any of the tested variables. Secondary analysis comparing the between limb difference in the injured and the uninjured groups, confirmed that previously injured hamstrings were mostly weaker (+180°s(-1)p=0.2208; +60°s(-1)p=0.0379; -60°(-1)p=0.0312; -180°s(-1)p=0.0110) and that deficits in sEMG were confined to the BF during eccentric contractions (-60°s(-1)p=0.0542; -180°s(-1)p=0.0473). Previously injured hamstrings were weaker and BF sEMG activity was lower than the contralateral uninjured hamstring. This has implications for hamstring strain injury prevention and rehabilitation which should consider altered neural function following hamstring strain injury. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Effect of time-dependent cryotherapy on redox balance of quadriceps injuries.

    PubMed

    Silva, Marco Aurélio dos Santos; Carvalho, Taiara Ramos de; Cruz, Amanda Cristina Marques Barros da; Jesus, Lennon Rafael Guedine de; Silva Neto, Larissa Alexsandra da; Trajano, Eduardo Tavares Lima; Bezerra, Frank Silva

    2016-02-01

    Muscle trauma represents a high number of injuries in professional sport and recreation and may occur through several mechanisms. This study aims at analyzing time-dependent effects of cryotherapy on the redox balance in lesioned quadriceps muscles in F1 mice. Twenty male F1 mice were divided into five groups: (a) animals were not subjected to muscle lesioning or treatment (CTR); (b) quadriceps muscle was lesioned without treatment (L); (c) quadriceps muscle was lesioned and treated with cryotherapy for 5 min (LC5); (d) quadriceps muscle was lesioned and treated with cryotherapy for 20 min (LC20); and quadriceps muscle was lesioned and treated with cryotherapy for 40 min (LC40). The mice were euthanized; the quadriceps muscles were collected and subjected to analyses for levels of protein, hydroperoxides, nitrite, catalase (CAT) activity, oxidized glutathione (GSSG) and reduced glutathione (GSH). Protein levels were reduced in L (-39%; p < 0.05), LC5 (-54%; p < 0.05), LC20 (-40%; p < 0.05) and LC40 (-50%; p < 0.05) compared to CTR. There was an increase in lipid peroxidation in L (158%; p < 0.05), LC5 (300%; p < 0.01), LC20 (292%; p < 0.01) and LC40 (362%; p < 0.01) compared to CTR. We observed a significant increase in CAT activity in L (164%; p < 0.05) and LC5 (193%; p < 0.01) compared to CTR; a significant reduction in GSH in L (-60%; p < 0.05) and LC20 (-61%; p < 0.05) compared to CTR; and a significant increase in GSSG in LC5 (171%; p < 0.05) compared to CTR. In addition, GSH/GSSG was reduced in L (-89%; p < 0.01), LC5 (-95%; p < 0.01), LC20 (-59%; p < 0.05), and LC40 (-82%; p < 0.01) compared to CTR. This study showed that the cryotherapy does not improve the oxidative stress in lesioned muscles.

  15. Evidence for interneuronally mediated Ia excitatory effects to human quadriceps motoneurones.

    PubMed Central

    Fournier, E; Meunier, S; Pierrot-Deseilligny, E; Shindo, M

    1986-01-01

    The possibility was investigated that interneuronal pathways contribute to Ia excitation of quadriceps motoneurones in normal man. Two techniques were used: the indirect spatial facilitation technique for investigating summation of Ia excitatory effects in interneurones which may be interposed in pathways to quadriceps motoneurones; the post-stimulus time histogram method for time course measurement of the firing probability of voluntarily activated motor units following femoral nerve stimulation. The spatial facilitation technique was applied while using the quadriceps H reflex to assess the excitability of the whole motoneurone pool: the comparison was made between the excitatory effects of two conditioning stimuli applied either separately or together. Summation of effects at a premotoneuronal level is suggested if facilitation of the reflex evoked on combined conditioning stimulation is larger than the algebraic sum of facilitations evoked by separate stimuli. Quadriceps tendon tap and electrical stimulations applied to either the femoral nerve or to two of its branches, the nerves to the vastus lateralis and vastus medialis muscles, were used as conditioning stimuli. Since these stimuli were very weak (their strength being about at the threshold for facilitation of the test reflex), it can be assumed that they activated predominantly Ia fibres. The facilitation of the quadriceps H reflex evoked on combined stimulation was significantly larger than the algebraic sum of facilitations evoked by separate stimuli. In many experiments, although conditioning stimuli did not evoke any reflex facilitation when applied alone, a significant facilitation appeared on combined stimulation. This 'extra' facilitation of the reflex on combined stimulation appeared with a central latency of 4-5 ms. It is argued that the only mechanism compatible with such a latency is summation at a premotoneuronal level. Post-stimulus time histograms (p.s.t.h.s) of voluntarily activated

  16. The interaction between the vastus medialis and vastus intermedius and its influence on the extensor apparatus of the knee joint.

    PubMed

    Grob, Karl; Manestar, Mirjana; Filgueira, Luis; Kuster, Markus S; Gilbey, Helen; Ackland, Timothy

    2017-01-25

    Although the vastus medialis (VM) is closely associated with the vastus intermedius (VI), there is a lack of data regarding their functional relationship. The purpose of this study was to investigate the anatomical interaction between the VM and VI with regard to their origins, insertions, innervation and function within the extensor apparatus of the knee joint. Eighteen human cadaveric lower limbs were investigated using macro-dissection techniques. Six limbs were cut transversely in the middle third of the thigh. The mode of origin, insertion and nerve supply of the extensor apparatus of the knee joint were studied. The architecture of the VM and VI was examined in detail, as was their anatomical interaction and connective tissue linkage to the adjacent anatomical structures. The VM originated medially from a broad hammock-like structure. The attachment site of the VM always spanned over a long distance between: (1) patella, (2) rectus femoris tendon and (3) aponeurosis of the VI, with the insertion into the VI being the largest. VM units were inserted twice-once on the anterior and once on the posterior side of the VI. The VI consists of a complex multi-layered structure. The layers of the medial VI aponeurosis fused with the aponeuroses of the tensor vastus intermedius and vastus lateralis. Together, they form the two-layered intermediate layer of the quadriceps tendon. The VM and medial parts of the VI were innervated by the same medial division of the femoral nerve. The VM consists of multiple muscle units inserting into the entire VI. Together, they build a potential functional muscular complex. Therefore, the VM acts as an indirect extensor of the knee joint regulating and adjusting the length of the extensor apparatus throughout the entire range of motion. It is of clinical importance that, besides the VM, substantial parts of the VI directly contribute to the medial pull on the patella and help to maintain medial tracking of the patella during knee

  17. The Effects of Different Stretching Techniques of the Quadriceps Muscles on Agility Performance in Female Collegiate Soccer Athletes: A Pilot Study

    PubMed Central

    Gillis, C. B.; Martinez, N. J.

    2008-01-01

    Background Stretching has long been an integral component of pre-performance activities for a multitude of athletic endeavors. Previous research has demonstrated that stretching may have detrimental effects on performance. Specific knowledge of the precise effects of stretching may influence the decision to appropriately apply stretching techniques in the sport and therapeutic settings. Objective The purpose of this pilot study was to examine the effects of static stretching, proprioceptive neuromuscular facilitation (contract-relax) stretching, and no stretching of the quadriceps muscle group on agility performance. Methods Twelve healthy, female, collegiate soccer players aged 18 – 25 performed one of the three stretching protocols (static, contract-relax, no stretch) and the agility test (T-test) on three non-consecutive days. Agility times were recorded and compared based on stretching technique and day that each test was performed. Results No significant difference was found among the means of the different stretching techniques. The t-test agility performance times were as follows: control, =9.7 seconds; static stretch, =9.73 seconds; and contract-relax, =9.62 seconds. Conclusion The results of this study suggest that agility performance may be independent of stretching technique of the quadriceps performed in female collegiate soccer athletes. It is recommended that female soccer athletes about to engage in agility activity may perform either no stretch, static stretch, or contract-relax stretching according to individual preference. PMID:21509139

  18. The effects of different stretching techniques of the quadriceps muscles on agility performance in female collegiate soccer athletes: a pilot study.

    PubMed

    Wallmann, H W; Gillis, C B; Martinez, N J

    2008-02-01

    Stretching has long been an integral component of pre-performance activities for a multitude of athletic endeavors. Previous research has demonstrated that stretching may have detrimental effects on performance. Specific knowledge of the precise effects of stretching may influence the decision to appropriately apply stretching techniques in the sport and therapeutic settings. The purpose of this pilot study was to examine the effects of static stretching, proprioceptive neuromuscular facilitation (contract-relax) stretching, and no stretching of the quadriceps muscle group on agility performance. Twelve healthy, female, collegiate soccer players aged 18 - 25 performed one of the three stretching protocols (static, contract-relax, no stretch) and the agility test (T-test) on three non-consecutive days. Agility times were recorded and compared based on stretching technique and day that each test was performed. No significant difference was found among the means of the different stretching techniques. The t-test agility performance times were as follows: control, =9.7 seconds; static stretch, =9.73 seconds; and contract-relax, =9.62 seconds. The results of this study suggest that agility performance may be independent of stretching technique of the quadriceps performed in female collegiate soccer athletes. It is recommended that female soccer athletes about to engage in agility activity may perform either no stretch, static stretch, or contract-relax stretching according to individual preference.

  19. Quadriceps and hamstrings morphology is related to walking mechanics and knee cartilage MRI relaxation times in young adults.

    PubMed

    Kumar, Deepak; Subburaj, Karupppasamy; Lin, Wilson; Karampinos, Dimitrios C; McCulloch, Charles E; Li, Xiaojuan; Link, Thomas M; Souza, Richard B; Majumdar, Sharmila

    2013-12-01

    Controlled laboratory study using a cross-sectional design. To analyze the relationship of quadriceps-hamstrings and medial-lateral quadriceps anatomical cross-sectional area (ACSA) ratios with knee loads during walking and articular and meniscal cartilage composition in young, healthy subjects. Muscle forces affect knee loading during walking, but it is not known if muscle morphology is associated with walking mechanics and cartilage composition in young subjects. Forty-two knees from 27 young, healthy, active volunteers (age, 20-35 years; body mass index, <28 kg/m(2)) underwent 3-T magnetic resonance imaging (MRI) and 3-D motion capture. Standard MRI sequences were used for articular and meniscal cartilage T1rho and T2 relaxation times and for quadriceps and hamstrings muscle ACSA. Frontal plane kinetics during the stance phase of walking was calculated. Generalized estimating equation models were used to identify muscle variables that predicted MRI and gait parameters. Quadriceps-hamstrings and medial-lateral quadriceps ACSA ratios were positively related to frontal plane loading (β = .21-.54, P≤.006), global articular cartilage relaxation times (β = .22-.28, P≤.041), and the medial-lateral ratio of meniscus T1rho relaxation time (β = .26-.36, P≤.049). The medial-lateral quadriceps ACSA ratio was positively related to global meniscus T1rho relaxation times (β = .30, P = .046). Higher quadriceps-hamstrings and medial-lateral quadriceps ACSA ratios were associated with higher frontal plane loading during walking and with articular and meniscal cartilage T1rho and T2 relaxation times. These findings highlight the relationships between different knee tissues and knee mechanics in young, healthy individuals.

  20. Changes in voluntary quadriceps activation predict changes in muscle strength and gait biomechanics following knee joint effusion.

    PubMed

    Pietrosimone, Brian; Lepley, Adam S; Murray, Amanda M; Thomas, Abbey C; Bahhur, Nael O; Schwartz, Todd A

    2014-09-01

    It has been hypothesized that arthrogenic muscle inhibition is responsible for altering physical function following knee injury. The association between the onset of arthrogenic muscle inhibition, measured using voluntary quadriceps activation, and changes in muscle strength and gait biomechanics are unknown. Outcomes were collected before and following a 60 ml experimental knee effusion in eighteen healthy participants. Voluntary quadriceps activation was the predictor variable, while the criterion variable included, maximal voluntary isometric strength, peak knee flexion angle, peak internal knee extension moment, and peak vertical ground reaction forces during the first half of stance phase upon stair descent. Percent change scores (Δ) were imputed into linear regression equations to determine associations between predictor and criterion variables. The variance in Δ voluntary quadriceps activation significantly predicted 87% the variance in the Δ strength (R(2)=0.87, P<0.001; Δ strength=-2.15+1.77Δ voluntary quadriceps activation) and 25% of the Δ vertical ground reaction force following effusion (R(2)=0.25, P=0.04; Δ vertical ground reaction force=-6.1+0.57 Δ voluntary quadriceps activation). After accounting for Δ knee flexion angle, Δ voluntary quadriceps activation predicted an additional 29% (Δ R(2)=0.29, P=0.007) of the variance in the Δ knee extension moment (R(2)=0.54, P=0.003, Δ knee extension moment=-10.79+0.74Δ knee flexion angle+1.64Δ voluntary quadriceps activation) following knee effusion. Immediate quadriceps activation deficits following joint effusion result in immediate alterations in muscle strength, knee extensor moment and vertical ground reaction force during gait. Published by Elsevier Ltd.

  1. Quadriceps and Hamstrings Morphology Is Related to Walking Mechanics and Knee Cartilage MRI Relaxation Times in Young Adults

    PubMed Central

    KUMAR, DEEPAK; SUBBURAJ, KARUPPPASAMY; LIN, WILSON; KARAMPINOS, DIMITRIOS C.; MCCULLOCH, CHARLES E.; LI, XIAOJUAN; LINK, THOMAS M.; SOUZA, RICHARD B.; MAJUMDAR, SHARMILA

    2015-01-01

    STUDY DESIGN Controlled laboratory study using a cross-sectional design. OBJECTIVES To analyze the relationship of quadriceps-hamstrings and medial-lateral quadriceps anatomical cross-sectional area (ACSA) ratios with knee loads during walking and articular and meniscal cartilage composition in young, healthy subjects. BACKGROUND Muscle forces affect knee loading during walking, but it is not known if muscle morphology is associated with walking mechanics and cartilage composition in young subjects. METHODS Forty-two knees from 27 young, healthy, active volunteers (age, 20-35 years; body mass index, <28 kg/m2) underwent 3-T magnetic resonance imaging (MRI) and 3-D motion capture. Standard MRI sequences were used for articular and meniscal cartilage T1rho and T2 relaxation times and for quadriceps and hamstrings muscle ACSA. Frontal plane kinetics during the stance phase of walking was calculated. Generalized estimating equation models were used to identify muscle variables that predicted MRI and gait parameters. RESULTS Quadriceps-hamstrings and medial-lateral quadriceps ACSA ratios were positively related to frontal plane loading (β = .27-.54, P≤.006), global articular cartilage relaxation times (β = .22-.28, P≤.041), and the medial-lateral ratio of meniscus T1rho relaxation time (β = .26-.36, P≤.049). The medial-lateral quadriceps ACSA ratio was positively related to global meniscus T1rho relaxation times (β = .30, P = .046). CONCLUSION Higher quadriceps-hamstrings and medial-lateral quadriceps ACSA ratios were associated with higher frontal plane loading during walking and with articular and meniscal cartilage T1rho and T2 relaxation times. These findings highlight the relationships between different knee tissues and knee mechanics in young, healthy individuals. PMID:24175607

  2. ACL deficient potential copers and non-copers reveal different isokinetic quadriceps strength profiles in the early stage after injury

    PubMed Central

    Eitzen, I; Eitzen, TJ; Holm, I; Snyder-Mackler, L; Risberg, MA

    2011-01-01

    Background Isokinetic muscle strength tests using the peak torque value is the most frequently included quadriceps muscle strength measurement for anterior cruciate ligament (ACL) injured subjects. Aims The purpose of this study was to investigate quadriceps muscle performance during the whole isokinetic curve in ACL deficient subjects classified as potential copers or non-copers, and investigate whether these curve profiles were associated with single-leg hop performance. We hypothesized that quadriceps muscle torque at other knee flexion angles than peak torque would give more information about quadriceps muscle strength deficits. Furthermore, we hypothesized that there would be significant torque differences between potential copers and non-copers, and a significant relationship between angle specific torque values and single-leg hop performance. Study Design Cross-sectional study; Level of evidence, 2 Methods Seventy-six individuals with a complete unilateral ACL rupture within the last 3 months were included. The subjects were classified into potential copers and non-copers according to the criteria from Fitzgerald et al12. Isokinetic quadriceps muscle tests were performed at 60°/sec (Biodex 6000). Mean torque values were calculated for peak torque as well as for specific knee flexion angles. The one-leg hop and the 6 meter timed hop tests were included and symmetry indices were used. Results The peak torque value did not identify the largest quadriceps muscle strength deficit. Rather, these were established at knee flexion angles of less than 40°. There were significant differences in angle specific torque values between potential copers and non-copers (p<0.05). Moderate to strong associations were disclosed between angle specific torque values and single-leg hop performance, but only for non-copers (r≥0.32– 0.58). Conclusions Angle specific quadriceps muscle torque values of less than 40° of knee flexion provide more information on the quadriceps

  3. Surgical management of acute quadriceps tendon rupture (a case report with literature review)

    PubMed Central

    Ennaciri, Badr; Montbarbon, Eric; Beaudouin, Emmanuel

    2015-01-01

    Quadriceps tendon rupture is uncommon and often overlooked in emergency. Tearing affects weakening tendon by systemic diseases or some medications. The mechanism is generally indirect. Inability to actively extend the knee associated to a supra-patellar defect evoke easily the diagnosis without other investigations. Surgical repair is realized in emergency to completely restore the extension. We report a case of a patient who has sustained of complete quadriceps tendon tear after a long period of tendon weakening by statin therapy, hypertension and diabetes. The repair has consisted on end-to-end Krackow sutures associated with bone suture to the proximal pole of the patella. Surgeons and emergency physicians must think to this form of extensor apparatus rupture, because early diagnosis leads to early treatment and to best outcomes. PMID:26958106

  4. Acute effects of static stretching on peak torque and the hamstrings-to-quadriceps conventional and functional ratios.

    PubMed

    Costa, P B; Ryan, E D; Herda, T J; Walter, A A; Defreitas, J M; Stout, J R; Cramer, J T

    2013-02-01

    Recent evidence has shown acute static stretching may decrease hamstring-to-quadriceps (H:Q) ratios. However, the effects of static stretching on the functional H:Q ratio, which uses eccentric hamstrings muscle actions, have not been investigated. This study examined the acute effects of hamstrings and quadriceps static stretching on leg extensor and flexor concentric peak torque (PT), leg flexor eccentric PT, and the conventional and functional H:Q ratios. Twenty-two women (mean ± SD age=20.6 ± 1.9 years; body mass=64.6 ± 9.1 kg; height=164.5 ± 6.4 cm) performed three maximal voluntary unilateral isokinetic leg extension, flexion, and eccentric hamstring muscle actions at the angular velocities of 60 and 180°/s before and after a bout of hamstrings, quadriceps, and combined hamstrings and quadriceps static stretching, and a control condition. Two-way repeated measures ANOVAs (time × condition) were used to analyze the leg extension, flexion, and eccentric PT as well as the conventional and functional H:Q ratios. Results indicated that when collapsed across velocity, hamstrings-only stretching decreased the conventional ratios (P<0.05). Quadriceps-only and hamstrings and quadriceps stretching decreased the functional ratios (P<0.05). These findings suggested that stretching may adversely affect the conventional and functional H:Q ratios.

  5. Efficacy of kinesio taping on isokinetic quadriceps torque in knee osteoarthritis: a double blinded randomized controlled study.

    PubMed

    Anandkumar, Sudarshan; Sudarshan, Shobhalakshmi; Nagpal, Pratima

    2014-08-01

    Double blind pre-test post-test control group design. To compare the isokinetic quadriceps torque, standardized stair-climbing task (SSCT) and pain during SSCT between subjects diagnosed with knee osteoarthritis pre and post kinesio tape (KT) application with and without tension. Strength of the quadriceps and torque producing capability is frequently found to be compromised in knee osteoarthritis. The efficacy of KT in improving isokinetic quadriceps torque in knee osteoarthritis is unknown, forming the basis for this study. Forty subjects were randomly allocated to either the experimental (therapeutic KT with tension) or control group (sham KT without tension) with the allocation being concealed. Pre and post test measurements of isokinetic quadriceps torque, SSCT and pain during SSCT were carried out by a blinded assessor. A large effect size with significant improvements in the peak quadriceps torque (concentric and eccentric at angular velocities of 90° per second and 120° per second), SSCT and pain were obtained in the experimental group when compared to the control group. Application of therapeutic KT is effective in improving isokinetic quadriceps torque, SSCT and reducing pain in knee osteoarthritis.

  6. Improvements in quadriceps sensorimotor function and disability of patients with knee osteoarthritis following a clinically practicable exercise regime.

    PubMed

    Hurley, M V; Scott, D L

    1998-11-01

    Quadriceps sensorimotor dysfunction may be important in the pathogenesis of knee osteoarthritis (OA) and a determinant of disability. Exercise regimes can increase quadriceps strength, but whether this improves proprioception and reduces disability is uncertain. Moreover, research regimes involve protracted treatment which is clinically impracticable. We compared quadriceps sensorimotor function and disability in 60 patients with knee OA, before and after an exercise regime, with a control group (n = 37) who did not exercise. Exercise improved quadriceps strength (mean change, 95% CI; 73 N, 26-19 N), voluntary activation (14%, 5-20%), knee joint position sense (0.6 degrees, 0.1-1.8 degrees), and reduced the Lequesne Index (3.5, 0.5-4) and aggregate time of four activities of daily living (8.4 s, 0.2-16.7 s). At 6 month follow-up, these improvements were maintained. The parameters of the control group were unchanged. These results substantiate the association between quadriceps sensorimotor dysfunction and disability, emphasizing the importance of quadriceps exercise in the management of knee OA. The regimen is relatively brief and clinically practicable, but could be adapted to make it more cost effective.

  7. Enthesitis of the direct tendon of the rectus femoris muscle in a professional volleyball player: A case report

    PubMed Central

    Bortolotto, C.; Coscia, D.R.; Ferrozzi, G.

    2011-01-01

    Enthesitis of the direct tendon of the rectus femoris muscle is a rare pathology which mainly affects professional athletes, and it is caused by overuse and repetitive microtrauma. Athletic jumping and kicking exert a great stress on the direct tendon of the rectus femoris muscle, and volleyball and football players are therefore most frequently affected. Enthesitis may occur suddenly causing pain and functional impairment possibly associated with partial or complete tendon injuries, or it may be a chronic condition causing non-specific clinical symptoms. We present the case of a professional volleyball player who felt a sudden pain in the left side of the groin area during a training session although she had suffered no accidental injury. The pain was associated with impaired ipsilateral limb function. Tendon rupture was suspected, and magnetic resonance imaging (MRI) was performed. MRI showed a lesion at the myotendinous junction associated with marked inhomogeneity of the direct tendon. Ultrasound (US) examination confirmed the presence of both lesions and allowed a more detailed study of the pathology. This is a typical case of enthesitis which confirms that MRI should be considered the examination of choice in hip pain, particularly when the patient is a professional athlete, thanks to its panoramic visualization. However, also US is an ideal imaging technique for evaluating tendon injuries thanks to its high spatial resolution, and it can therefore be used effectively as a second line of investigation. PMID:23396666

  8. Enthesitis of the direct tendon of the rectus femoris muscle in a professional volleyball player: A case report.

    PubMed

    Bortolotto, C; Coscia, D R; Ferrozzi, G

    2011-06-01

    Enthesitis of the direct tendon of the rectus femoris muscle is a rare pathology which mainly affects professional athletes, and it is caused by overuse and repetitive microtrauma. Athletic jumping and kicking exert a great stress on the direct tendon of the rectus femoris muscle, and volleyball and football players are therefore most frequently affected. Enthesitis may occur suddenly causing pain and functional impairment possibly associated with partial or complete tendon injuries, or it may be a chronic condition causing non-specific clinical symptoms.We present the case of a professional volleyball player who felt a sudden pain in the left side of the groin area during a training session although she had suffered no accidental injury. The pain was associated with impaired ipsilateral limb function. Tendon rupture was suspected, and magnetic resonance imaging (MRI) was performed. MRI showed a lesion at the myotendinous junction associated with marked inhomogeneity of the direct tendon. Ultrasound (US) examination confirmed the presence of both lesions and allowed a more detailed study of the pathology.This is a typical case of enthesitis which confirms that MRI should be considered the examination of choice in hip pain, particularly when the patient is a professional athlete, thanks to its panoramic visualization. However, also US is an ideal imaging technique for evaluating tendon injuries thanks to its high spatial resolution, and it can therefore be used effectively as a second line of investigation.

  9. Functional Reconstruction of a Combined Tendocutaneous Defect of the Achilles Using a Segmental Rectus Femoris Myofascial Construct: A Viable Alternative

    PubMed Central

    DeFazio, Michael Vincent; Han, Kevin Dong

    2014-01-01

    The composite anterolateral thigh flap with vascularized fascia lata has emerged as a workhorse at our institution for complex Achilles defects requiring both tendon and soft tissue reconstruction. Safe elevation of this flap, however, is occasionally challenged by absent or inadequate perforators supplying the anterolateral thigh. When discovered intraoperatively, alternative options derived from the same vascular network can be pursued. We present the case of a 74-year-old male who underwent composite Achilles defect reconstruction using a segmental rectus femoris myofascial free flap. Following graduated rehabilitation, postoperatively, the patient resumed full activity and was able to ambulate on his tip-toes. At 1-year follow-up, active total range of motion of the reconstructed ankle exceeded 85% of the unaffected side, and donor site morbidity was negligible. American Orthopaedic Foot and Ankle Society and Short Form-36 scores improved by 78.8% and 28.8%, respectively, compared to preoperative baseline assessments. Based on our findings, we advocate for use of the combined rectus femoris myofascial free flap as a rescue option for reconstructing composite Achilles tendon/posterior leg defects in the setting of inadequate anterolateral thigh perforators. To our knowledge, this is the first report to describe use of this flap for such an indication. PMID:24883281

  10. Quality properties and adsorption behavior of freeze-dried beef meat from the Biceps femoris and Semimembranosus muscles.

    PubMed

    Aykın, Elif; Erbaş, Mustafa

    2016-11-01

    The aim of this research was to determine the quality properties and adsorption behavior of freeze-dried beef meat from the Biceps femoris and Semimembranosus muscles. Most quality properties of both muscles were similar apart from total fat content. Freeze-dried meat pieces were kept in ten different equilibrium levels of relative humidity (2.0-97.3%) at 5, 15, 25 and 30°C. The experimental data were evaluated using BET (Brunauer-Emmett-Teller) and GAB (Guggenheim, Anderson and deBoer) models. The equilibrium moisture contents of freeze-dried Biceps femoris were lower than those of Semimembranosus at all water activities and temperature. The constants m0 and C of BET and GAB equations were determined to be between 6.27 and 8.07g/100g dry matter and 9.32-13.73, respectively. Constant k was about 0.90 at all temperatures, and the GAB equation exhibited a better fit to the experimental data of both muscles as a result of all %E values being approximately equal to 10%. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Real-time measurement of rectus femoris muscle kinematics during drop jump using ultrasound imaging: a preliminary study.

    PubMed

    Eranki, Avinash; Cortes, Nelson; Ferencek Gregurić, Zrinka; Kim, John J; Sikdar, Siddhartha

    2012-01-01

    We have developed an office based vector tissue Doppler imaging (vTDI) that can be used to quantitatively measure muscle kinematics using ultrasound. The goal of this preliminary study was to investigate if vTDI measures are repeatable and can be used robustly to measure and understand the kinematics of the rectus femoris muscle during a drop jump task. Data were collected from 8 healthy volunteers. Vector TDI along with a high speed camera video was used to better understand the dynamics of the drop jump. Our results indicate that the peak resultant vector velocity of the rectus femoris immediately following landing was repeatable across trials (intraclass correlation coefficient=0.9).The peak velocity had a relatively narrow range in 6 out of 8 subjects (48-62 cm/s), while in the remaining two subjects it exceeded 70 cm/s. The entire drop jump lasted for 1.45 0.27 seconds. The waveform of muscle velocity could be used to identify different phases of the jump. Also, the movement of the ultrasound transducer holder was minimal with peak deflection of 0.91 0.54 degrees over all trials. Vector TDI can be implemented in a clinical setting using an ultrasound system with a research interface to better understand the muscle kinematics in patients with ACL injuries.

  12. Clinical utility of the Duncan-Ely test for rectus femoris dysfunction during the swing phase of gait.

    PubMed

    Marks, M C; Alexander, J; Sutherland, D H; Chambers, H G

    2003-11-01

    The Ely Test (or Duncan-Ely test) has been accepted as a clinical tool to assess rectus femoris spasticity by passively flexing the knee rapidly while the patient lies prone in a relaxed state. In this retrospective review, patients' dynamic knee range of motion (ROM) during gait and an electromyogram (EMG) were compared with the results of the Ely test. Data for 70 patients (44 males, 26 females; 104 limbs) were included. Mean age of patients was 13 years, SD 9 years, range 4 years 5 months to 54 years. All patients were diagnosed with cerebral palsy (spastic diplegia, n = 42; spastic quadriplegia, n = 15, and hemiplegia, n = 13). All patients were ambulatory (50 independent, 20 with assistive devices). A standard matrix was used to calculate sensitivity and specificity of the Ely test as well as its positive and negative predictive value. For the gait variables examined (decreased dynamic knee ROM, timing of peak knee flexion, and abnormal EMG in swing) the sensitivity of the Ely test ranged from 56 to 59% and the specificity ranged from 64 to 85%. For the same variables the positive predictive value ranged from 91 to 98% and the negative predictive value ranged from 4 to 19%. The Ely test was shown to have a good positive predictive value (i.e. the certainty about the presence of rectus spasticity in patients with a positive Ely test result) for rectus femoris dysfunction during gait.

  13. The relationship between shear force, compression, collagen characteristics, desmin degradation and sarcomere length in lamb biceps femoris.

    PubMed

    Starkey, Colin P; Geesink, Geert H; van de Ven, Remy; Hopkins, David L

    2017-04-01

    This study aimed to identity the relationships between known variants of tenderness (collagen content (total and soluble), desmin degradation and sarcomere length) and shear force and compression in the biceps femoris aged for 14days from 112 mixed sex lambs. Desmin degradation was related to compression (P<0.05) such that as desmin degradation increased compression decreased. Sarcomere length (SL) was related to shear force (P<0.05), such that as SL increased shear force declined. Shear force was also related to compression (P<0.05), and soluble collagen (P<0.05), with male lambs producing higher shear force values than females (4.4±1.72N: P<0.05) when adjusted for compression, sarcomere length and soluble collagen. The findings from this experiment indicate that the known variants (soluble collagen, sarcomere length and desmin degradation) are related to shear force and compression in ovine biceps femoris. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  14. Study of the control strategy of the quadriceps muscles in anterior knee pain.

    PubMed

    Cesarelli, M; Bifulco, P; Bracale, M

    2000-09-01

    Anterior knee pain (AKP) is a common pathological condition, particularly among young people and athletes, associated to an abnormal motion of the patella during the bending of the knee and possibly dependent on a muscular or structural imbalance. A lack of synergy in the quadriceps muscles results in a dynamic misalignment of the patella, which in turn produces pain. AKP rehabilitative therapy consists of conservative treatment whose main objective is to strengthen the Vastus Medialis. The aim of this article is to study the quadriceps muscle control strategy in AKP patients during an isokinetic exercise. Analysis of the muscle activation strategy is important for an objective measurement of the knee functionality in that it helps to diagnose and monitor the rehabilitative treatment. Surface electromyography (EMG) from the three superficial muscles of the femoral quadriceps during a concentric isokinetic exercise has been analyzed along with the signals of knee joint position and torque. A group of 12 AKP patients has been compared with a group of 30 normal subjects. Analysis of the grand ensemble average of the EMG linear envelopes in AKP patients reveals significant modifications in Vastus Medialis activity compared to the other quadriceps muscles. In order to study the synergy of the muscles, temporal identifiers have been associated to the EMG linear envelopes. To this end, EMG linear envelope decomposition in Gaussian pulses turned out to be effective and the results highlight an appreciable delay in the activation of the Vastus Medialis in AKP patients. This muscular unbalance can explain the abnormal motion of the patella.

  15. Quadriceps Rate of Force Development affects Gait and Function in People with Knee Osteoarthritis

    PubMed Central

    Winters, Joshua D.; Rudolph, Katherine S.

    2014-01-01

    Objective Quadriceps weakness exists in people with knee osteoarthritis (OA) but other muscle factors like rate of force development (RFD) may also be affected by knee OA. The purpose of this study was to determine if people with knee OA have deficits in quadriceps RFD, determine if quadriceps RFD would improve predicting knee joint power absorption and generation during free and fast walking, and determine if RFD would improve predicting functional outcomes. Methods 26 subjects with knee OA and 23 healthy control subjects performed maximal voluntary isometric strength (MVIC) and RFD measures of the quadriceps. Subjects also underwent a 3-D motion analysis of both self-selected free and self-selected fast walking speeds. Joint kinetics were calculated from inverse dynamics. Results RFD was not different by group (p=0.763), however the OA subjects generated the highest peak RFD at a lower %MVIC (p=0.008). Controls walked significantly faster at both free and fast walking speeds (p=0.001, p=0.029). Knee angles at heel strike and peak knee extension were lower (p=0.004, p=0.027) in the OA group. During fast walking knee power generation was higher in Controls (p=0.028). MVIC and force of highest peak RFD predicted KOOS ADL score in the OA subjects, but only MVIC predicted stair climbing time. Conclusions The submaximal force at which peak RFD occurs plays a significant role in knee joint power as well as functional measures in the OA subjects, providing further evidence that factors other than maximal strength are also important in people with knee OA. PMID:24240535

  16. Fatigue affects peak joint torque angle in hamstrings but not in quadriceps.

    PubMed

    Coratella, Giuseppe; Bellin, Giuseppe; Beato, Marco; Schena, Federico

    2015-01-01

    Primary aim of this study was to investigate peak joint torque angle (i.e. the angle of peak torque) changes recorded during an isokinetic test before and after a fatiguing soccer match simulation. Secondarily we want to investigate functional Hecc:Qconc and conventional Hconc:Qconc ratio changes due to fatigue. Before and after a standardised soccer match simulation, twenty-two healthy male amateur soccer players performed maximal isokinetic strength tests both for hamstrings and for quadriceps muscles at 1.05 rad · s(‒1), 3.14 rad · s(‒1) and 5.24 rad · s(‒1). Peak joint torque angle, peak torque and both functional Hecc:Qconc and conventional Hconc:Qconc ratios were examined. Both dominant and non-dominant limbs were tested. Peak joint torque angle significantly increased only in knee flexors. Both eccentric and concentric contractions resulted in such increment, which occurred in both limbs. No changes were found in quadriceps peak joint torque angle. Participants experienced a significant decrease in torque both in hamstrings and in quadriceps. Functional Hecc:Qconc ratio was lower only in dominant limb at higher velocities, while Hconc:Qconc did not change. This study showed after specific fatiguing task changes in hamstrings only torque/angle relationship. Hamstrings injury risk could depend on altered torque when knee is close to extension, coupled with a greater peak torque decrement compared to quadriceps. These results suggest the use eccentric based training to prevent hamstrings shift towards shorter length.

  17. Polypropylene mesh augmentation for complete quadriceps rupture after total knee arthroplasty.

    PubMed

    Nodzo, Scott R; Rachala, Sridhar R

    2016-01-01

    Polypropylene mesh has previously been shown to be an effective treatment for failed patellar tendon repairs after total knee arthroplasty (TKA), but there have been few reports of this synthetic mesh used in complete quadriceps rupture after TKA. We retrospectively reviewed seven consecutive cases in six patients with complete quadriceps tears after TKA who had their quadriceps tendon repaired with suture and polypropylene mesh augmentation. All but two patients had previously failed primary suture repair. Patient outcomes were evaluated using the Knee Society Score. Standardized anterior-posterior (AP), lateral and merchant radiographs were evaluated preoperatively and at final follow-up. Seven knees in six patients were evaluated with a mean follow-up of 34±10 (range 24 to 49months) months. There were only four clinical successes defined as an extensor lag less than 30°. Of the functioning knees at final follow-up (n=5) the overall extensor lag in this group did significantly improve from 50±13° to 20±15° (range 5 to 40°) (p=.01). Mean postoperative flexion at final follow-up was 115±8°. Mean Knee Society Score for function improved from 20±30 to 45±54 (p=.03) as did the mean Knee Society Score for pain (44±18 vs. 74±78, p=.02). Polypropylene mesh offered limited postoperative functional results when used as an augment to the multiply operated knee that sustains a complete quadriceps rupture after TKA, but did allow for significant improvement in postoperative pain outcomes. IV. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. [Isokinetic torque of quadriceps in patients with untreated anterior cruciate ligament injury of the knee joint].

    PubMed

    Ikeda, H

    1993-09-01

    In order to study the role of muscle strength in patients with untreated anterior cruciate ligament (ACL) injury of the knee joint, the torque of the quadriceps was isokinetically measured during concentric contraction (CC) and passive eccentric contraction (PEC). The results were compared with those in normal individuals and sports players. Ninety patients with untreated ACL injury were subjected for the study. There were 50 men and 40 women. The normal group consisted of 20 students and the sports player group consisted of 20 soccer players. The peak torque and the torque at 30 degrees flexion of the quadriceps were isokinetically measured during CC and PEC by using a BIODEX machine. In patients with ACL injury, the peak torque was smaller in the injured side as compared with the uninjured side. At the same angle velocity, decrease of PEC in the injured side was larger than that of CC. These results were compared with the normal group and the sports player group. There was significant difference in the peak torque per body weight among each groups. But, the torque per body weight at 30 degrees flexion was almost consistent in these three groups. A considerable quadriceps atrophy occurs following ACL injury. In our experience, patients with functional absence of ACL are much more difficult to return to vigorous sports which require explosive eccentric contraction than to return to endurance sports which require repetitive concentric contractile efforts of the quadriceps. In the present study, decrease of the passive eccentric contraction in the injured side was more pronounced than that of the concentric contraction. From these results, the significantly decreased passive eccentric torque in the patients with untreated ACL injury can be a factor to cause instability of the knee joint in active daily life as well as in sports activities.

  19. THE EFFECTS OF VARIED TENSIONS OF KINESIOLOGY TAPING ON QUADRICEPS STRENGTH AND LOWER LIMB FUNCTION.

    PubMed

    de Jesus, Julio Fernandes; Franco, Yuri Rafael Dos Santos; Nannini, Stella Bispo; Nakaoka, Gustavo Bezerra; Dos Reis, Amir Curcio; Bryk, Flavio Fernandes

    2017-02-01

    Kinesiology Taping (KT) may promote changes in muscle strength and motor performance, topics of great interest in the sports-medicine sciences. These characteristics are purported to be associated with the tension generated by the KT on the skin. However, the most suitable tension for the attainment of these strength and performance effects has not yet been confirmed. The purpose of the present study was to analyze the effects of different tensions of KT on the isometric contraction of the quadriceps and lower limb function of healthy individuals over a period of seven days. Blind, randomized, clinical trial. One hundred and thirty healthy individuals were distributed into the following five groups: control (without KT); KT0 (KT without tension); KT50; KT75 and KT100 (approximately 50%, 75% and 100% tension applied to the tape, respectively). Assessments of isometric quadriceps strength were conducted using a hand held dynamometer. Lower limb function was assessed through Single Hop Test for Distance, with five measurement periods: baseline; immediately after KT application; three days after KT; five days after KT; and 72h after KT removal (follow-up). There were no statistically significant differences (p > 0.05) at any of the studied periods on participants' quadriceps strength nor in the function of the lower dominant limb, based on comparisons between the control group and the experimental groups. KT applied with different tensions did not produce modulations, in short or long-term, on quadriceps' strength or lower limb function of healthy individuals. Therefore, this type of KT application, when seeking these objectives, should be reconsidered. 1b.

  20. [Missed diagnosis in delayed recognition of bilateral simultaneous rupture of the quadriceps tendons].

    PubMed

    Wick, M; Müller, E J; Ekkernkamp, A; Muhr, G

    1997-04-01

    In this article we report a very rare case of simultaneous and bilateral rupture of the quadriceps tendon in a 38-year-old patient. The initial diagnosis was "herniated vertebral disk". Although there was an extensive neurological and psychiatric examination in combination with several operations, it took almost 3 months until the real reason was found. In this case report we describe our postoperative treatment of early mobilization and compare it with other therapies.

  1. Explosive hamstrings-to-quadriceps force ratio of males versus females.

    PubMed

    Hannah, Ricci; Folland, Jonathan P; Smith, Stephanie L; Minshull, Claire

    2015-04-01

    Females are known to exhibit a greater risk of ACL injury compared to males. Lower explosive hamstrings-to-quadriceps (H/Q) force ratio in the first 150 ms from activation onset could reflect an impaired capacity for knee joint stabilisation and increased risk of ACL injury. However, the explosive H/Q force ratio has not been compared between the sexes. The neuromuscular performance of untrained males and females (20 of each) was assessed during a series of isometric knee flexor and extensor contractions, specifically explosive and maximum voluntary contractions of each muscle group. Force, in absolute terms and normalised to body mass, and surface EMG of the hamstrings and quadriceps were recorded. Hamstrings force was expressed relative to quadriceps force to produce ratios of explosive H/Q force and H/Q maximum voluntary force (MVF). For the explosive contractions, agonist electromechanical delay (EMD) and agonist neural activation were also assessed. The H/Q MVF ratio was greater in males (56 %) than females (50 %; P < 0.001). However, the explosive H/Q force ratio was similar between the sexes at each time point (25-150 ms) from activation onset. Explosive hamstrings, but not quadriceps, force relative to body mass was greater for males compared to females. There were no sex differences in EMD or agonist activation for either of the muscle groups. The lack of a sex difference in early phase isometric explosive H/Q force ratio suggests other factors might be more important in determining the substantially higher knee injury rates of females.

  2. Dynamic in vivo 3-dimensional moment arms of the individual quadriceps components.

    PubMed

    Wilson, Nicole A; Sheehan, Frances T

    2009-08-25

    The purpose of this study was to provide the first in vivo 3-dimensional (3D) measures of knee extensor moment arms, measured during dynamic volitional activity. The hypothesis was that the vastus lateralis (VL) and vastus medialis (VM) have significant off-axis moment arms compared to the central quadriceps components. After obtaining informed consent, three 3D dynamic cine phase contrast (PC) MRI sets (x,y,z velocity and anatomic images) were acquired from 22 subjects during active knee flexion and extension. Using a sagittal-oblique and two coronal-oblique imaging planes, the origins and insertions of each quadriceps muscle were identified and tracked through each time frame by integrating the cine-PC velocity data. The moment arm (MA) and relative moment (RM, defined as the cross product of the tendon line-of-action and a line connecting the line-of-action with the patellar center of mass) were calculated for each quadriceps component. The tendencies of the VM and VL to produce patellar tilt were evenly balanced. Interestingly, the magnitude of RM-P(Spin) for the VM and VL is approximately four times greater than the magnitude of RM-P(Tilt) for the same muscles suggesting that patellar spin may play a more important role in patellofemoral kinematics than previously thought. Thus, a force imbalance that leads to excessive lateral tilt, such as VM weakness in patellofemoral pain syndrome, would produce excessive negative spin (positive spin: superior patellar pole rotates laterally) and to a much greater degree. This would explain the increased negative spin found in recent studies of patellar maltracking. Assessing the contribution of each quadriceps component in three dimensions provides a more complete understanding of muscle functionality.

  3. The effect of quadriceps muscle fatigue on position matching at the knee.

    PubMed

    Givoni, Nathan J; Pham, Tuan; Allen, Trevor J; Proske, Uwe

    2007-10-01

    This is a report of the effects of exercise on position matching at the knee. Young adult subjects were required to step down a set of stairs (792 steps), representing eccentric-biased exercise of the quadriceps muscle, or step up them, concentric-biased exercise. Immediately after eccentric exercise subjects showed a mean force drop of 28% (+/- 6%, s.e.m.) of the control value in their exercised quadriceps muscle, which was accompanied by 4.8 deg (+/- 0.8 deg) of error between reference and matching legs in a position matching task at the knee. Similarly concentric exercise was followed by a force drop of 15% (+/- 3%) and matching errors of 3.7 deg (+/- 0.4 deg). These effects were significant. The direction of the errors suggested that subjects perceived their exercised muscles to be longer that they actually were. This finding was not consistent with the hypothesis that the increase in effort required to support the leg after fatigue from exercise was responsible for the errors. It is hypothesized that position sense in an unsupported leg arises, in part, from operation of an internal forward model. When the motor command is increased to compensate for the effects of fatigue, the comparison between predicted and actual feedback from quadriceps leads to the impression that the muscle is longer than it actually is. The exercise effects on proprioception may have implications for sports injuries and for evaluation of the factors leading to falls in the elderly.

  4. Acute effects of cold pack on mechanical properties of the quadriceps muscle in healthy subjects.

    PubMed

    Mustalampi, Sirpa; Ylinen, Jari; Kautiainen, Hannu; Weir, Adam; Häkkinen, Arja

    2012-11-01

    To examine the effects of local cooling on mechanical properties of the quadriceps muscle in healthy subjects. Thirty-nine healthy subjects (27 women, 12 men, mean age 39, range 20-62) volunteered. A cold gel pack was applied to the quadriceps muscle for 20 min. Properties were quantified by analyzing the frequency (tension), decrement (elasticity) and stiffness of damped oscillations and the compliance of the muscle before, immediately after and after 15-min after cooling. The largest responses immediately after cooling were seen in the oscillation decrement parameter, 7.9 (3.7-12.1) %, and in the compliance parameter, -7.5 (-9.8 to -5.3) %. Responses in the oscillation frequency, 6.5 (2.3-10.6) %, and stiffness parameters, 4.0 (0.8-7.1) %, were also statistically significant. The compliance still showed a -6.1 (-7.7 to -4.5) % decrease after the 15 min recovery phase, while no remaining alteration was found in the oscillation parameters. The quadriceps muscle became tenser, stiffer, and less elastic as a result of cooling, and the mechanical properties were not fully recovered after 15 min. Careful warming-up is suggested after cooling to enable normalization of mechanical properties of the muscle and to avoid injuries. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. A 6-week Sprint Interval Training Program Changes Anaerobic Power, Quadriceps Moment, and Subcutaneous Tissue Thickness.

    PubMed

    Han, Seunguk; Lee, Hyungkyu; Kim, Hyungkee; Kim, Dasol; Choi, Changkyu; Park, Jihong

    2017-02-01

    We examined the effects of a 6-week 40-m one-way sprint interval training program (based on sprint time). 13 untrained healthy male collegiate students performed six 40-m sprints with a 60-s resting interval between sprints during the first week, and one sprint was added each week until the sixth week. If the 40-m sprint time exceeded 110% of the fastest baseline 40-m sprint time, the run was repeated. Repeated-sprint cycling test (every 3 weeks), quadriceps moment (every 2 weeks), and abdominal and thigh subcutaneous tissue thickness (every 2 weeks) were measured. Compared to baseline, mean power output improved at week 3 (16.27 vs. 17.73 Watt/kg, p=0.004). Regardless of side, quadriceps moment began to increase at week 4 (2.88 vs. 3.15 N·m/kg, p=0.03). Subcutaneous tissue thickness was reduced at week 2 (abdominal: 11.19 vs. 9.65 mm, p=0.01; thigh: 9.17 vs. 8.12 mm, p=0.009). Our results suggest that (1) sprint training with an intensity of 110% of the fastest baseline 40-m sprint time with the addition of one sprint per week produces similar effects to other training programs, and (2) untrained individuals need 4 weeks of training for strength development in the quadriceps and 2 weeks for reduction in fat tissue thickness.

  6. Surgical Treatment of Neglected Traumatic Quadriceps Tendon Rupture with Knee Ankylosis

    PubMed Central

    Lee, Seung-Hun; Seon, Jong-Keun; Woo, Seong-Hwan

    2016-01-01

    Quadriceps tendon rupture is an uncommon injury. This disabling condition is the result of direct or indirect trauma. It requires surgical repair to avoid poor outcomes in cases of neglected or chronic rupture. In most acute cases, simple tendon suture or reinsertion is suitable for an extensor mechanism reconstruction of the knee joint. However, chronic lesions often require a tendon graft or flap reconstruction. We report a case of a 15-year-old male who was diagnosed with a chronic quadriceps rupture with a patellar superior pole fracture. We performed quadriceps reconstruction using tibialis anterior allograft tendon and additional screw fixation to reconstruct the extensor mechanism and recover knee joint range of motion to prevent a high-level functional restriction. The treatment was difficult and limited due to neglect for 9-months that led to ankylosis accompanied with nonunion of tibial fracture. Our surgical treatment using allograft tendon resulted in a very good outcome after 30 months of follow-up. PMID:27274474

  7. Ultrasound characteristics of the patellar and quadriceps tendons among young elite athletes.

    PubMed

    Visnes, H; Tegnander, A; Bahr, R

    2015-04-01

    Tendons adapt in response to sports-specific loading, but sometimes develop tendinopathy. If the presence of ultrasound changes like hypoechoic areas and neovascularization in asymptomatic tendons precede (and predict) future tendon problems is unknown. The aim of this prospective cohort study was to investigate the relationship between the development of ultrasound changes in the patellar and quadriceps tendons and symptoms of jumper's knee, as well to examine the medium-term effects of intensive training on tendon thickness among adolescent athletes. Elite junior volleyball athletes were followed with semi-annual ultrasound and clinical examinations (average follow-up: 1.7 years). Of the 141 asymptomatic athletes included, 22 athletes (35 patellar tendons) developed jumper's knee. In a multivariate logistic regression analysis, a baseline finding of a hypoechoic tendon area (odds ratio 3.3, 95% confidence interval 1.1 to 9.2) increased the risk of developing symptoms of jumper's knee. Patellar tendon thickness among healthy athletes did not change (Wilk's lambda, P = 0.07) while quadriceps tendon thickness increased (P = 0.001). In conclusion, ultrasound changes at baseline were risk factors for developing symptoms of jumper's knee. Also, among healthy athletes, we observed a 7-11% increase in quadriceps tendon thickness, while there was no increase in patellar tendon thickness.

  8. Adductor canal block can result in motor block of the quadriceps muscle.

    PubMed

    Chen, Junping; Lesser, Jonathan B; Hadzic, Admir; Reiss, Wojciech; Resta-Flarer, Francesco

    2014-01-01

    The block of nerves in the adductor canal is considered to cause a sensory block without a motor component. In this report, we describe a case of significant quadriceps muscle weakness after an adductor canal block (ACB). A 65-year-old female patient for ambulatory knee surgery was given an ACB for postoperative pain management. The block was performed under ultrasound guidance at the midthigh level using the transsartorial approach. Twenty milliliters of 0.5% ropivacaine was deposited adjacent to the anterior and posterior areas of the femoral artery. On discharge from the hospital, the patient realized that her thigh muscles were weak and she was unable to extend her leg at the knee. A neuromuscular examination indicated that the patient had no strength in her quadriceps muscle, along with sensory deficit in the medial-anterior lower leg and area in front of knee up to the midthigh. The weakness lasted 20 hours, and the sensory block lasted 48 hours before complete recovery. The optimal level and amount of local anesthetic for adductor canal block are currently not well defined. Proximal spread of local anesthetic and anatomical variation may explain our observation. Several studies have reported that ACB involves no motor blockade. However, our case report illustrates that the ACB can result in clinically significant quadriceps muscle paralysis. This report suggests that patients should be monitored vigilantly for this occurrence to decrease the risk of falls.

  9. Inflammatory cytokine expression in the quadriceps of rats with posttraumatic knee stiffness: A preliminary study.

    PubMed

    Liu, Kemin; Wang, Fei; Cui, Zhigang; Liu, Sihai; Han, Xinzuo

    2015-06-01

    The primary purpose of this study was to investigate cytokine expression in the quadriceps of rats with posttraumatic knee stiffness (PTKS) and to determine the effect of exercise training on these cytokines at different follow-up time points. The PTKS rats were randomly assigned into two even groups. The treatment group received exercise training, while the control group received no treatment. Quadriceps specimens were harvested randomly from each group at 8, 12, 16, and 20 weeks. RT-qPCR and immunohistochemical analyses were used to assess the protein and mRNA expression levels of the cytokines IL-1, IL-2, TNF-α, COX-1, and COX-2. TNF-α immunostaining did not differ between the treated and control group tissues, whereas weak immunostaining was observed for all other cytokines in the specimens from the treatment group compared with those from the control group at approximately 12 and 20 weeks. The cytokine levels decreased at approximately 8 weeks in the treatment group, whereas these levels remained elevated or plateaued in the control group. These differences were statistically significant (p<0.05). This study demonstrated that the expression of cytokines IL-1, IL-2, COX-1, and COX-2 increased in the quadriceps of rats with PTKS and that exercise training affected the observed profile trends of these cytokines.

  10. Asymptomatic Achilles, patellar, and quadriceps tendinopathy: a longitudinal clinical and ultrasonographic study in elite fencers.

    PubMed

    Giombini, A; Dragoni, S; Di Cesare, A; Di Cesare, M; Del Buono, A; Maffulli, N

    2013-06-01

    Lower limb tendon changes detected at imaging are common among asymptomatic athletes. We aimed to prospectively assess the clinical status, tendon structure, and vascularity of lower limb tendons of elite fencers, and predict the risk of developing symptoms over time. Clinical examination, changes at ultrasonography (US), and Power Doppler (PD) flow of both the Achilles, patellar, and quadriceps tendon were assessed in 37 elite fencers in January 2007 and 3 years after. Two hundred and twenty-two tendons were examined. At the last appointment, patellar tendons diagnosed as abnormal at baseline were more likely to develop symptoms than those normal at baseline (P < 0.05, Fisher's exact test), while US and PD abnormalities on Achilles and quadriceps tendons were no predictive for development of symptoms over years. A very low percentage of tendons diagnosed as normal at baseline (1.45%) showed US abnormalities at 3-year follow-up. In asymptomatic elite fencers, structural changes are relatively common at US and PD assessment of Achilles, quadriceps, and patellar tendons. It seems unlikely that additional PD investigations provide further information or change prognosis in patients with US diagnosis of tendinopathy.

  11. Iatrogenic Pseudo-aneurysm of Profunda Femoris Artery Following Fixation of Intertrochanteric Femur Fracture – A Case Report and Review of Literature

    PubMed Central

    Aggarwal, Rishi Anil; Purohit, Shaligram; Bandagi, Gokul; Marathe, Nandan

    2016-01-01

    The Profunda Femoris is a common site for arterial pseudo-aneurysms and these have been described in literature following fractures as well as orthopaedic procedures of the femur and hip region. These are an uncommon complication and a high index of suspicion is required for correct diagnosis and prompt management. We present a case of pseudo-aneurysm of the Profunda Femoris in an operated case of Intertrochanteric femur fracture with acute presentation. The case was managed successfully by angiographic coil embolization. PMID:27134957

  12. Influence of thigh muscles on the axial strains in a proximal femur during early stance in gait.

    PubMed

    Cristofolini, L; Viceconti, M; Toni, A; Giunti, A

    1995-05-01

    This work is focused on the in vitro simulation of the loads occurring in the femur during early stance in gait, for hip prosthesis stress shielding test purposes. Ten thigh muscles (the three gluteal muscles, the three vasti, rectus femoris, adductor longus and magnus, biceps femoris), simulated by nylon straps, were tested in order to establish their influence on the strains in the proximal femur. Axial and hoop strains were recorded from 16 strain gauges for the effect of each muscle and compared to the strains recorded as a result of the hip joint reaction force only (i.e. without muscle simulation). It appears that the three glutei are the principal muscles in determining the vertical strains, however the rectus femoris, biceps femoris and the adductors were also seen to significantly affect the strain pattern. The inadequacy of increasing the adduction angle and applying the resultant force at the hip joint to simulate the abductors was also confirmed.

  13. Acute effects of static and dynamic stretching on hamstring eccentric isokinetic strength and unilateral hamstring to quadriceps strength ratios.

    PubMed

    Ayala, Francisco; De Ste Croix, Mark; Sainz De Baranda, Pilar; Santonja, Fernando

    2013-01-01

    The main purposes of this study were to investigate the acute effects of static and dynamic lower limb stretching routines: (a) on peak torque, total external work and joint angle at peak torque of the hamstrings during maximal eccentric isokinetic leg flexion; (b) on unilateral hamstring to quadriceps (H/Q) strength ratios; as well as (c) to determine whether static and dynamic routines elicit similar responses. A total of 49 active adults completed the following intervention protocols in a randomised order on separate days: (a) non-stretching (control condition), (b) static stretching, and (c) dynamic stretching. After the stretching or control intervention, eccentric isokinetic peak torque, the angle of peak torque and total external work were assessed with participants prone at 1.04 and 3.14 rad · s(-1). Unilateral strength ratios of the knee were also recorded. Measures were compared via a fully-within-groups factorial analysis of variance (ANOVA). There were no main effects for eccentric isokinetic peak torque, angle of peak torque, total external work and unilateral H/Q strength ratios. The results suggest that dynamic and static stretching has no influence on eccentric strength profile and unilateral H/Q strength ratios and hence both forms of stretching do not reduce these two primary risk factors for muscle injury.

  14. Higher hamstring-to-quadriceps isokinetic strength ratio during the first post-operative months in patients with quadriceps tendon compared to hamstring tendon graft following ACL reconstruction.

    PubMed

    Fischer, Felix; Fink, Christian; Herbst, Elmar; Hoser, Christian; Hepperger, Caroline; Blank, Cornelia; Gföller, Peter

    2017-03-21

    The aim of this study was to compare isokinetic quadriceps and hamstring muscle strength in patients following anterior cruciate ligament (ACL) reconstruction who received either hamstring (HT) or quadriceps (QT) tendon autografts at two time intervals within the first year after surgery. One hundred twenty-four patients, 81 males (age 22.0 ± 6.2 years) and 43 females (age 20.9 ± 8.7 years), participated in this study. ACL reconstruction was performed with either quadriceps tendon autografts (QT; n = 61) or hamstring tendon autografts (HT; n = 63). Two isokinetic muscle strength tests (t1: 5.5 ± 1.2 months; t2: 7.6 ± 1.6 months) were performed at an angular velocity of 60°/s in both the injured and contralateral knees. An independent t test as well as a two-factor analysis of variance with repeated measurements was used. The significance level was set at p < 0.05. A statistically significant lower knee extensor strength was observed in the QT group within one year after surgery (p < 0.001). Additionally, data showed a significant higher H/Q ratio in QT patients compared to the HT group at t1 (p < 0.001) and t2 (p = 0.001) as well as a significant effect over time (p < 0.001) and interaction effect of time and graft (p = 0.007). Side-to-side values for extensor muscle strength were significantly (p < 0.001) greater in HT graft patients, while QT patients showed significantly (p < 0.001) greater values for flexor muscle strength at both time points of isokinetic testing, respectively. The results of this study indicate that graft choice has an impact on extensor strength in the first months after ACL reconstruction; however, there is no impact on flexor strength. The finding of a higher H/Q ratio in patients with QT grafts within the first months following surgery is possibly of clinical relevance. This may potentially be associated with lower stress on the maturing ACL graft. Furthermore, normal thigh strength can be restored

  15. A model of dynamic sacro-iliac joint instability from malrecruitment of gluteus maximus and biceps femoris muscles resulting in low back pain.

    PubMed

    Hossain, M; Nokes, L D M

    2005-01-01

    The objective of this work is to propose a biomechanical model of sacro-iliac joint dysfunction as a cause of low back pain. Sacro-iliac joint is known to be a source of low back pain. We also know that it is a very stable joint with little mobility. Surrounding lower limb and back muscles contribute a major part of this stability. Gait analysis studies have revealed an orderly sequence of muscle activation when we walk - that contributes to efficient stabilisation of the joint and effective weight transfer to the lower limb. Gluteus maximus fibres-lying almost perpendicular to the joint surfaces are ideally oriented for this purpose. Biceps femoris is another important muscle that can also influence joint stability by its proximal attachment to sacrotuberous ligament. Altered pattern of muscle recruitment has been observed in patients with low back pain. But we do not know the exact cause-effect relationship. Because of its position as a key linkage in transmission of weight from the upper limbs to the lower, poor joint stability could have major consequences on weight bearing. It is proposed that sacro-iliac joint dysfunction can result from malrecruitment of gluteus maximus motor units during weight bearing. This results in compensatory biceps over activation. The resulting soft tissue strain and joint instability may manifest itself in low back pain. If our hypothesis holds true, it may have positive implications for patients with sacro-iliac joint dysfunction - who could be offered a definite diagnosis and targeted physiotherapy. It may be possible to identify patients early in a primary care setting and offer direct physio referral. They could benefit from exercises to improve strengthening and recruitment of the affected muscles.

  16. Eccentric and concentric isokinetic moment characteristics in the quadriceps and hamstrings of the chronic isolated posterior cruciate ligament injured knee

    PubMed Central

    MacLean, C. L.; Taunton, J. E.; Clement, D. B.; Regan, W.

    1999-01-01

    OBJECTIVE: Functional strength deficits associated with chronic isolated posterior cruciate ligament (PCL) insufficiency have received limited attention in the literature. The purpose of this study was to determine the eccentric and concentric isokinetic moment characteristics of the quadriceps and hamstrings in a sample of patients with isolated PCL injury. METHODS: Eccentric and concentric mean average and average peak moments were measured for 17 patients with a history of conservatively treated isolated PCL injury using an isokinetic dynamometer. Quadriceps and hamstring isokinetic moments were recorded from 10 degree to 90 degree of knee flexion. Strength ratios were calculated and compared with those reported in the literature for healthy subjects. RESULTS: The hamstrings of the involved side (eccentric/concentric (E/C) ratio = 1.06) were significantly weaker (p<0.05) eccentrically than those of the contralateral side (E/C ratio = 1.29). All hamstrings/quadriceps (H/Q) ratios were less than the universally accepted value of 0.60 and the eccentric H/Q ratio for the injured extremity was significantly lower than the non-injured (p<0.05). In a bilateral comparison, the injured/non-injured (I/N) ratio was less than 1.00 for concentric quadriceps, eccentric quadriceps, and hamstring isokinetic moments. Calculation of the E/C ratio showed that, for the quadriceps, it was 1.08 on the injured side and 1.07 on the non-injured extremity. CONCLUSIONS: Eccentric strengthening should be an integral part of functionally rehabilitating the quadriceps and hamstrings of athletes who suffer from the complications associated with chronic isolated PCL insufficiency. 


 PMID:10597850

  17. Physical principles demonstrate that the biceps femoris muscle relative to the other hamstring muscles exerts the most force: implications for hamstring muscle strain injuries.

    PubMed

    Dolman, Bronwyn; Verrall, Geoffrey; Reid, Iain

    2014-07-01

    Of the hamstring muscle group the biceps femoris muscle is the most commonly injured muscle in sports requiring interval sprinting. The reason for this observation is unknown. The objective of this study was to calculate the forces of all three hamstring muscles, relative to each other, during a lengthening contraction to assess for any differences that may help explain the biceps femoris predilection for injury during interval sprinting. To calculate the displacement of each individual hamstring muscle previously performed studies on cadaveric anatomical data and hamstring kinematics during sprinting were used. From these displacement calculations for each individual hamstring muscle physical principles were then used to deduce the proportion of force exerted by each individual hamstring muscle during a lengthening muscle contraction. These deductions demonstrate that the biceps femoris muscle is required to exert proportionally more force in a lengthening muscle contraction relative to the semimembranosus and semitendinosus muscles primarily as a consequence of having to lengthen over a greater distance within the same time frame. It is hypothesized that this property maybe a factor in the known observation of the increased susceptibility of the biceps femoris muscle to injury during repeated sprints where recurrent higher force is required.

  18. Physical principles demonstrate that the biceps femoris muscle relative to the other hamstring muscles exerts the most force: implications for hamstring muscle strain injuries

    PubMed Central

    Dolman, Bronwyn; Verrall, Geoffrey; Reid, Iain

    2014-01-01

    Summary Of the hamstring muscle group the biceps femoris muscle is the most commonly injured muscle in sports requiring interval sprinting. The reason for this observation is unknown. The objective of this study was to calculate the forces of all three hamstring muscles, relative to each other, during a lengthening contraction to assess for any differences that may help explain the biceps femoris predilection for injury during interval sprinting. To calculate the displacement of each individual hamstring muscle previously performed studies on cadaveric anatomical data and hamstring kinematics during sprinting were used. From these displacement calculations for each individual hamstring muscle physical principles were then used to deduce the proportion of force exerted by each individual hamstring muscle during a lengthening muscle contraction. These deductions demonstrate that the biceps femoris muscle is required to exert proportionally more force in a lengthening muscle contraction relative to the semimembranosus and semitendinosus muscles primarily as a consequence of having to lengthen over a greater distance within the same time frame. It is hypothesized that this property maybe a factor in the known observation of the increased susceptibility of the biceps femoris muscle to injury during repeated sprints where recurrent higher force is required. PMID:25506583

  19. Histochemical study, morphometric analysis and systematic distribution of fiber types in the rectus femoris muscle of the albino rats.

    PubMed

    Vega-Alvarez, J A; Pena, C; Bengoechea, M P; Perez-Casas, A

    1989-06-01

    The histochemical and morphometric characteristics as well as the systematic distribution of fiber types in the muscle rectus femoris (RF) of adult male rats were studied from ATPase (pre-incubated at pH 9'4, 4'6 and 4'2) and NADH stained sections. The muscle fiber types were classified as I type, IIA type and IIB-type. In 20 RF muscles 90-95% of total fibers were sampled and the mean diameter, length and irregularity-degree analysed. The data were grouped in four quadrants and the percent of fiber types was determined. The type IIB fibers predominate in all quadrants. The largest fibers were the IIB type and the smallest ones the type I, for all the quadrants. Our findings support a functional compartmentalization as proposed by many authors.

  20. Segond fracture: involvement of the iliotibial band, anterolateral ligament, and anterior arm of the biceps femoris in knee trauma.

    PubMed

    De Maeseneer, Michel; Boulet, Cedric; Willekens, Inneke; Lenchik, Leon; De Mey, Johan; Cattrysse, Erik; Shahabpour, Maryam

    2015-03-01

    To evaluate the involvement of the iliotibial band (ITB), the anterolateral ligament (ALL), and the anterior arm of the biceps femoris in MRI-diagnosed Segond fracture and to evaluate other associated findings of Segond fracture. We retrospectively reviewed the MRI of 13 cases of Segond fracture. The studies included proton density-weighted, T2-weighted, and proton density-weighted with fat saturation images in the three planes. We studied 2 cadaveric specimens with emphasis on the ALL. One cadaveric specimen was dissected while the other was sectioned in the sagittal plane. The mean age of the patients was 36 years (range, 17-52). There were 7 men and 6 women. The mean size of the Segond bone fragment was 8 × 10 × 2 mm. The distance from the tibia varied from 2 to 6 mm. Associated findings included anterior cruciate ligament (ACL) tear (n = 13), medial collateral ligament (MCL) tear (n = 8), meniscocapsular tear of the posterior horn of the medial meniscus (n = 5), and posterolateral corner involvement (n = 4). Bone marrow edema involved the mid-lateral femoral condyle and the posterior tibial plateau on both the medial and the lateral side. Edema at the Segond area was seen, but was limited. Fibular head edema was also seen. The ITB (11 out of 13) and ALL (10 out of 13) inserted on the Segond bone fragment. The anterior arm of the biceps tendon did not insert on the Segond fracture. Associated findings of Segond fracture include ACL tear, MCL tear, medial meniscus tear, and posterolateral corner injury. Both the ITB and the ALL may be involved in the Segond avulsion. The anterior arm of the biceps femoris tendon is not involved.

  1. Longitudinal sequencing in intramuscular coordination: A new hypothesis of dynamic functions in the human rectus femoris muscle

    PubMed Central

    von Laßberg, Christoph; Rapp, Walter; Stutzig, Norman

    2017-01-01

    The punctum fixum-punctum mobile model has been introduced in previous publications. It describes general principles of intersegmental neuromuscular succession patterns to most efficiently generate specific movement intentions. The general hypothesis of this study is that these principles—if they really do indicate a fundamental basis for efficient movement generation—should also be found in intramuscular coordination and should be indicated by “longitudinal sequencing” between fibers according to the principles of the punctum fixum-punctum mobile model. Based on this general hypothesis an operationalized model was developed for the rectus femoris muscle (RF), to exemplarily scrutinize this hypothesis for the RF. Electromyography was performed for 14 healthy male participants by using two intramuscular fine wire electrodes in the RF (placed proximal and distal), three surface electrodes over the RF (placed proximal, middle, and distal), and two surface electrodes over the antagonists (m. biceps femoris and m. semitendinosus). Three movement tasks were measured: kicking movements; deceleration after sprints; and passively induced backward accelerations of the leg. The results suggest that proximal fibers can be activated independently from distal fibers within the RF. Further, it was shown that the hypothesized function of “intramuscular longitudinal sequencing” does exist during dynamic movements. According to the punctum fixum-punctum mobile model, the activation succession between fibers changes direction (from proximal to distal or inversely) depending on the intentional context. Thus, the results seem to support the general hypothesis for the RF and could be principally in line with the operationalized “inter-fiber to tendon interaction model”. PMID:28817715

  2. Preactivation of the quadriceps muscle could limit cranial tibial translation in a cranial cruciate ligament deficient canine stifle.

    PubMed

    Ramirez, Juan M; Lefebvre, Michael; Böhme, Beatrice; Laurent, Cédric; Balligand, Marc

    2015-02-01

    Cranial cruciate ligament (CrCL) deficiency is the leading cause of lameness of the canine stifle. Application of tension in the quadriceps muscle could trigger cranial tibial translation in case of CrCL rupture. We replaced the quadriceps muscle and the gastrocnemius muscle by load cells and turn-buckles. First, eight canine limbs were placed in a servo-hydraulic testing machine, which applied 50% of body weight (BW). In a second phase, the CrCL was transected, and the limbs were tested in a similar manner. In a third phase, a quadriceps pretension of 15% BW was applied and limbs were again tested in a similar manner. Cranial tibial translation was significantly decreased in CrCL deficient stifles (p < 0.05) when quadriceps pretension was applied. These findings indicate that quadriceps pretension could play a role in the stability of a CrCL deficient stifle and should then be considered in rehabilitation programs and conservative treatment of CrCL rupture in dogs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Quadriceps Strength Asymmetry After Anterior Cruciate Ligament Reconstruction Alters Knee Joint Biomechanics and Functional Performance at Time of Return to Activity.

    PubMed

    Palmieri-Smith, Riann M; Lepley, Lindsey K

    2015-07-01

    Quadriceps strength deficits are observed clinically after anterior cruciate ligament (ACL) injury and reconstruction and are often not overcome despite rehabilitation. Given that quadriceps strength may be important for achieving symmetrical joint biomechanics and promoting long-term joint health, determining the magnitude of strength deficits that lead to altered mechanics is critical. To determine if the magnitude of quadriceps strength asymmetry alters knee and hip biomechanical symmetry as well as functional performance and self-reported function. Cross-sectional study; Level of evidence, 3. A total of 73 patients were tested at the time they were cleared for return to activity after ACL reconstruction. Quadriceps strength and activation, scores on the International Knee Documentation Committee form, the hop for distance test, and sagittal plane lower extremity biomechanics were recorded while patients completed a single-legged hop. Patients with high and moderate quadriceps strength symmetry had larger central activation ratios as well as greater limb symmetry indices on the hop for distance compared with patients with low quadriceps strength symmetry (P < .05). Similarly, knee flexion angle and external moment symmetry were higher in the patients with high and moderate quadriceps symmetry compared with those with low symmetry (P < .05). Quadriceps strength was found to be associated with sagittal plane knee angle and moment symmetry (P < .05). Patients with low quadriceps strength displayed greater movement asymmetries at the knee in the sagittal plane. Quadriceps strength was related to movement asymmetries and functional performance. Rehabilitation after ACL reconstruction needs to focus on maximizing quadriceps strength, which likely will lead to more symmetrical knee biomechanics. © 2015 The Author(s).

  4. Localized muscle vibration reverses quadriceps muscle hypotrophy and improves physical function: a clinical and electrophysiological study.

    PubMed

    Benedetti, Maria Grazia; Boccia, Gennaro; Cavazzuti, Lorenzo; Magnani, Elena; Mariani, Elisabetta; Rainoldi, Alberto; Casale, Roberto

    2017-07-18

    Quadriceps weakness has been associated with knee osteoarthritis (OA). High-frequency localized muscle vibration (LMV) has been proposed recently for quadriceps strengthening in patients with knee OA. The purpose of this study was (a) to investigate the clinical effectiveness of high-frequency LMV on quadriceps muscle in patients with knee OA and (b) to disentangle, by means of surface electromyography (sEMG), the underlying mechanism. Thirty patients, aged between 40 and 65 years, and clinically diagnosed with knee OA were included in this randomized, controlled, single-blinded pilot study. Participants were randomly assigned to two groups: a study group treated with LMV, specifically set for muscle strengthening (150 Hz), by means of a commercial device VIBRA, and a control group treated with neuromuscular electrical stimulation. Clinical outcome was measured using the Western Ontario and McMaster Universities Osteoarthritis Index, Visual Analogue Scale, knee range of motion, Timed Up and Go test, and Stair climbing test. To assess changes in muscle activation and fatigue a subgroup of 20 patients was studied with the use of sEMG during a sustained isometric contraction. The LMV group showed a significant change in Western Ontario and McMaster Universities Osteoarthritis Index score, Visual Analogue Scale score, Timed Up and Go test, Stair Climbing Test, and knee flexion. These improvements were not significant in patients treated with neuromuscular electrical stimulation. sEMG analysis suggested an increased involvement of type II muscle fibers in the group treated with LMV. In conclusion, the present study supports the effectiveness of local vibration in muscle function and clinical improvement of patients with knee OA.

  5. Sex-related differences in joint-angle-specific functional hamstring-to-quadriceps strength ratios.

    PubMed

    El-Ashker, Said; Carson, Brian P; Ayala, Francisco; De Ste Croix, Mark

    2017-03-01

    To examine and compare sex-related differences in the functioning of the hamstrings and quadriceps muscles and the isokinetic hamstrings eccentric-to-quadriceps concentric functional ratio (H/Q FUNC). Fifty male and 46 female young adults completed this study. Each participant carried out an isokinetic assessment to determine isokinetic concentric and eccentric torques during knee extension and flexion actions at 3 different angular velocities (60, 180 and 300°/s) adopting a lying position. The H/Q FUNC was calculated using peak torque (PT) values and 3 different joint-angle-specific torque values (15°, 30° and 45° of knee extension). A repeated measures analysis of variance was used to compare the results, and post hoc analyses using Friedman correction were employed. There were statistically significant effects of angular velocity, joint angle and sex on the H/Q FUNC (p < 0.01). Thus, the H/Q FUNC ratio in both males and females decreases closer to full knee extension and with increasing movement velocity. The H/Q FUNC was also significantly lower in females compared to males, irrespective of moment velocity and joint angle. The findings of the current study reinforce the need to examine the H/Q FUNC ratio closer to full knee extension (where knee injury is most likely to occur) rather than using PT values which may not be as informative, as well as to focus preventive and rehabilitation training programmes on reducing quadriceps dominance by enhancing eccentric hamstring strength (especially in females who are at higher risk of injury). III.

  6. The duration of the inhibitory effects with static stretching on quadriceps peak torque production.

    PubMed

    Siatras, Theophanis A; Mittas, Vasilios P; Mameletzi, Dimitra N; Vamvakoudis, Eystratios A

    2008-01-01

    Although several studies have investigated the acute effect of static stretching exercises, the duration of exercises that negatively affects performance has not been ascertained. This study was conducted to determine the acute effect of different static stretching durations on quadriceps isometric and isokinetic peak torque production. The 50 participants were randomly allocated into five equivalent sized groups and were asked to perform a stretching exercise of different duration (no stretch, 10-second stretch, 20-second stretch, 30-second stretch, and 60-second stretch). The knee flexion range of motion and the isometric and concentric isokinetic peak torques of the quadriceps were measured before and after a static stretching exercise in the four experimental groups. The same parameters were examined in the control group (no stretch) without stretching, before and after a 5-minute passive rest. There were no significant differences among groups before the experimentation regarding their physical characteristics and performances (P > 0.05). These results reflect the different groups' homogeneity. Significant knee joint flexibility increases (P < 0.001) and significant isometric and isokinetic peak torque reductions (P < 0.05-0.001) have been shown to occur only after 30 and 60 seconds of quadriceps static stretching. Stretching reduced isometric peak torque by 8.5% and 16.0%, respectively. Concerning isokinetic peak torque after 30 and 60 seconds of stretching, it was reduced by 5.5% vs. 11.6% at 60 degrees/s and by 5.8% vs. 10.0% at 180 degrees/s. We suggest that torque decrements are related to changes of muscle neuromechanical properties. It is recommended that static stretching exercises of a muscle group for more than 30 seconds of duration be avoided before performances requiring maximal strength.

  7. Quadriceps Function After Exercise in Patients with Anterior Cruciate Ligament–Reconstructed Knees Wearing Knee Braces

    PubMed Central

    Davis, Alexis G.; Pietrosimone, Brian G.; Ingersoll, Christopher D.; Pugh, Kelli; Hart, Joseph M.

    2011-01-01

    Context: Knee braces and neoprene sleeves are commonly worn by people with anterior cruciate ligament reconstructions (ACLRs) during athletic activity. How knee braces and sleeves affect muscle activation in people with ACLRs is unclear. Purpose: To determine the effects of knee braces and neoprene knee sleeves on the quadriceps central activation ratio (CAR) before and after aerobic exercise in people with ACLRs. Design: Crossover study. Patients or Other Participants: Fourteen people with a history of ACLR (9 women, 5 men: age = 23.61 ± 4.44 years, height = 174.09 ± 9.82 cm, mass = 75.35 ± 17.48 kg, months since ACLR = 40.62 ± 20.41). Intervention(s): During each of 3 sessions, participants performed a standardized aerobic exercise protocol on a treadmill. The independent variables were condition (brace, sleeve, or control) and time (baseline, pre-exercise with brace, postexercise with brace, postexercise without brace). Main Outcome Measure(s): Normalized torque measured during a maximal voluntary isometric contraction (TMVIC) and CAR were measured by a blinded assessor using the superimposed burst technique. The CAR was expressed as a percentage of full muscle activation. The quadriceps CAR and TMVIC were measured 4 times during each session: baseline, pre-exercise with brace, postexercise with brace, and postexercise without brace. Results: Immediately after the application of the knee brace, TMVIC decreased (P = .01), but no differences between bracing conditions were observed. We noted reduced TMVIC and CAR (P < .001) after exercise, both with and without the brace. No differences were seen between bracing conditions after aerobic exercise. Conclusions: The decrease in TMVIC immediately after brace application was not accompanied by differences between bracing conditions. Wearing a knee brace or neoprene sleeve did not seem to affect the deterioration of quadriceps function after aerobic exercise. PMID:22488186

  8. Normal isometric and isokinetic peak torques of hamstring and quadriceps muscles in young adult Saudi males.

    PubMed

    Alangari, Abdulrahman S; Al-Hazzaa, Hazzaa M

    2004-07-01

    To provide reference data for peak isometric and isokinetic muscle strength of hamstring and quadriceps muscles in young adult Saudi males. The strength of left and right quadriceps and hamstrings leg muscles was assessed in 132 college-male students in the campus of King Saud University, Riyadh, Kingdom of Saudi Arabia in the year 2002 using a Cybex machine and a standardized protocol at the following velocities: 0, 60, 180, and 300 degrees/sec. Isometric strength (0 degrees/sec) was assessed at 65 degrees angle of knee flexion. Isometric flexion strength was 9.3% higher in the right leg compared to the left (p < 0.01), while there was no significant difference between the 2 legs in extension. In isokinetic strength, there was a decrease in both extension and flexion strength with increasing velocity. However, only in flexion strength a significant right-left difference was observed. Flexion/extension peak concentric torque ratio relative to angular velocity varied from 59.9-63.3% in the right leg and from 55.8-59.9% in the left leg, with significant difference (p < 0.02) between the 2 legs. In addition, the angle of peak torque decreased with increasing velocity at knee extension but increased at knee flexion. Young Saudi males appeared to have similar isometric peak strength in the knee extensors but not in the flexors when compared to previously published research. Isokinetic extension strength at 60 degrees/sec in the Saudi males is lower than values reported for untrained males elsewhere. Furthermore, the hamstrings/quadriceps ratio in Saudi males seems to be within the recommended range of appropriate muscle function.

  9. THE EFFECTS OF VARIED TENSIONS OF KINESIOLOGY TAPING ON QUADRICEPS STRENGTH AND LOWER LIMB FUNCTION

    PubMed Central

    Franco, Yuri Rafael dos Santos; Nannini, Stella Bispo; Nakaoka, Gustavo Bezerra; dos Reis, Amir Curcio; Bryk, Flavio Fernandes

    2017-01-01

    Background Kinesiology Taping (KT) may promote changes in muscle strength and motor performance, topics of great interest in the sports-medicine sciences. These characteristics are purported to be associated with the tension generated by the KT on the skin. However, the most suitable tension for the attainment of these strength and performance effects has not yet been confirmed. Hypothesis/Purpose The purpose of the present study was to analyze the effects of different tensions of KT on the isometric contraction of the quadriceps and lower limb function of healthy individuals over a period of seven days. Study Design Blind, randomized, clinical trial. Methods One hundred and thirty healthy individuals were distributed into the following five groups: control (without KT); KT0 (KT without tension); KT50; KT75 and KT100 (approximately 50%, 75% and 100% tension applied to the tape, respectively). Assessments of isometric quadriceps strength were conducted using a hand held dynamometer. Lower limb function was assessed through Single Hop Test for Distance, with five measurement periods: baseline; immediately after KT application; three days after KT; five days after KT; and 72h after KT removal (follow-up). Results There were no statistically significant differences (p > 0.05) at any of the studied periods on participants’ quadriceps strength nor in the function of the lower dominant limb, based on comparisons between the control group and the experimental groups. Conclusion KT applied with different tensions did not produce modulations, in short or long-term, on quadriceps’ strength or lower limb function of healthy individuals. Therefore, this type of KT application, when seeking these objectives, should be reconsidered. Level of Evidence 1b PMID:28217419

  10. The acute transverse strain response of the patellar tendon to quadriceps exercise.

    PubMed

    Wearing, Scott C; Hooper, Sue L; Purdam, Craig; Cook, Jill; Grigg, Nicole; Locke, Simon; Smeathers, James E

    2013-04-01

    The human patellar tendon is highly adaptive to changes in habitual loading, but little is known about its acute mechanical response to exercise. This research evaluated the immediate transverse strain response of the patellar tendon to a bout of resistive quadriceps exercise. Twelve healthy adult males (mean age, 34.0 ± 12.1 yr; height, 1.75 ± 0.09 m; and weight, 76.7 ± 12.3 kg) free of knee pain participated in the research. A 10- to 5-MHz linear array transducer was used to acquire standardized sagittal sonograms of the right patellar tendon immediately before and after 90 repetitions of a double-leg parallel-squat exercise performed against a resistance of 175% bodyweight. Tendon thickness was determined 20-mm distal to the pole of the patellar, and transverse Hencky strain was calculated as the natural log of the ratio of post- to preexercise tendon thickness and expressed as a percentage. Measures of tendon echotexture (echogenicity and entropy) were also calculated from subsequent grayscale profiles. Quadriceps exercise resulted in an immediate decrease in patellar tendon thickness (P < 0.05), equating to a transverse strain of -22.5% ± 3.4% and was accompanied by increased tendon echogenicity (P < 0.05) and decreased entropy (P < 0.05). The transverse strain response of the patellar tendon was significantly correlated with both tendon echogenicity (r = -0.58, P < 0.05) and entropy after exercise (r = 0.73, P < 0.05), whereas older age was associated with greater entropy of the patellar tendon before exercise (r = 0.79, P < 0.05) and a reduced transverse strain response (r = 0.61, P < 0.05) after exercise. This study is the first to show that quadriceps exercise invokes structural alignment and fluid movement within the matrix that are manifested by changes in echotexture and transverse strain in the patellar tendon.

  11. Effects of quadriceps and hamstrings proprioceptive neuromuscular facilitation stretching on knee movement sensation.

    PubMed

    Streepey, Jefferson W; Mock, Marla J; Riskowski, Jody L; Vanwye, William R; Vitvitskiy, Boris M; Mikesky, Alan E

    2010-04-01

    Stretching before competition has traditionally been thought to benefit performance; however, recent evidence demonstrating reduced muscle force and power immediately after stretching suggests otherwise. We hypothesized that knee joint position sense would be diminished immediately after proprioceptive neuromuscular facilitation (PNF) stretching to the hamstrings and quadriceps. Eighteen subjects (aged 18-30 years) were seated with their dominant foot attached to a motorized arm with the knee flexed at 135 degrees . To block external cues, the subjects wore a blindfold, earplugs, and headphones providing white noise. The knee was displaced in either the flexion or the extension direction at a velocity of 0.4 degrees .s, and subjects pressed a button when they sensed motion. The knee was returned to 135 degrees , and the test was repeated for a total of 10 trials. The PNF group received PNF stretching to the hamstrings and quadriceps of the dominant leg. The SHAM group had the dominant leg passively moved within each subject's functional range of motion. The ability to detect knee movement was retested in the PNF and SHAM groups. Pre- and posttest latencies between movement onset and subject response were analyzed. Results indicated that the PNF group had significantly increased latencies after stretching (from 2.56 +/- 0.83 to 3.46 +/- 1.90 seconds) compared with the SHAM group (3.93 +/- 2.40 to 3.72 +/- 2.15 seconds). It is concluded that PNF stretching of the hamstrings and quadriceps may acutely diminish sensitivity to knee movement. For coaches and trainers, these findings are consistent with previous reports of loss in muscle force and power immediately after stretching, suggesting that stretching just before competition may diminish performance.

  12. Quadriceps function after exercise in patients with anterior cruciate ligament-reconstructed knees wearing knee braces.

    PubMed

    Davis, Alexis G; Pietrosimone, Brian G; Ingersoll, Christopher D; Pugh, Kelli; Hart, Joseph M

    2011-01-01

    Knee braces and neoprene sleeves are commonly worn by people with anterior cruciate ligament reconstructions (ACLRs) during athletic activity. How knee braces and sleeves affect muscle activation in people with ACLRs is unclear. To determine the effects of knee braces and neoprene knee sleeves on the quadriceps central activation ratio (CAR) before and after aerobic exercise in people with ACLRs. Crossover study. Fourteen people with a history of ACLR (9 women, 5 men: age = 23.61 ± 4.44 years, height = 174.09 ± 9.82 cm, mass = 75.35 ± 17.48 kg, months since ACLR = 40.62 ± 20.41). During each of 3 sessions, participants performed a standardized aerobic exercise protocol on a treadmill. The independent variables were condition (brace, sleeve, or control) and time (baseline, pre-exercise with brace, postexercise with brace, postexercise without brace). Normalized torque measured during a maximal voluntary isometric contraction (T(MVIC)) and CAR were measured by a blinded assessor using the superimposed burst technique. The CAR was expressed as a percentage of full muscle activation. The quadriceps CAR and T(MVIC) were measured 4 times during each session: baseline, pre-exercise with brace, postexercise with brace, and postexercise without brace. Immediately after the application of the knee brace, T(MVIC) decreased (P = .01), but no differences between bracing conditions were observed. We noted reduced T(MVIC) and CAR (P < .001) after exercise, both with and without the brace. No differences were seen between bracing conditions after aerobic exercise. The decrease in T(MVIC) immediately after brace application was not accompanied by differences between bracing conditions. Wearing a knee brace or neoprene sleeve did not seem to affect the deterioration of quadriceps function after aerobic exercise.

  13. Functional results following surgical repair of simultaneous bilateral quadriceps tendon ruptures.

    PubMed

    Chang, Edward S; Dodson, Christopher C; Tjoumakaris, Fotios; Cohen, Steven B; Chang, Edward S; Dodson, Christopher C; Tjoumakaris, Fotios; Cohen, Steven B

    2014-05-01

    Unilateral quadriceps tendon ruptures are common conditions treated by orthopedic surgeons. There is a paucity of information concerning functional outcomes in bilateral tendon ruptures. The aim of this study is to assess a series of 5 cases with simultaneous quadriceps tendon ruptures that underwent acute surgical repair with the purpose of identifying the functional outcomes as compared with unilateral injuries. We hypothesize that patients with bilateral quadriceps tendon ruptures have worse functional outcomes than patients with unilateral ruptures. Five cases of bilateral quadriceps tendon ruptures were identified. All patients underwent acute surgical extensor tendon repair employing a 3-patellar hole and a locked, running, nonabsorbable suture technique followed by a 6-week period of immobilization and bracing for 10 to 12 weeks. Mechanism of injury, medical history, social history, operative report, and postoperative exam were recorded with a minimum 1-year follow-up. In addition, each patient completed a subjective International Knee Documentation Committee (IKDC) score at 18 months. Five patients with unilateral injuries and with similar medical history were included as age-matched controls. The mean age for the bilateral group was 54.8 years (range, 44-68 years). Mean postoperative knee flexion was 129 degrees and all patients had active, resisted knee extension. Only 1 patient had a medical comorbidity (diabetes mellitus). The mean IKDC score (mean follow-up, 25.4 months; range, 22-29 months) was 71.9 (range, 34.4 to 91.6), whereas the age-matched control group had a mean IKDC score of 88.3 (P = 0.23). There was no statistical significance between the 2 groups with regard to range of motion (P = 0.24), IKDC score, and return to activity (P = 0.29). Patients with early surgical repair of bilateral, simultaneous extensor mechanism ruptures exhibit adequate recovery and return to a high level of function. Our patients were younger than those reported in

  14. Effects of Motorized vs Non-Motorized Treadmill Training on Hamstring/Quadriceps Strength Ratios

    PubMed Central

    Franks, Kelly A.; Brown, Lee E.; Coburn, Jared W.; Kersey, Robert D.; Bottaro, Martim

    2012-01-01

    Previous literature suggests that muscular involvement and biomechanical changes elicit different responses between overground and treadmill training. The objective of this study was to examine the effects of training on two different treadmill designs on the conventional (CR; concentric only) and functional (FR; eccentric to concentric) hamstring and quadriceps strength ratios. Fifteen men and sixteen women were randomly divided into three groups: motorized (MT), non-motorized (NMT) or control (C). Subjects completed pre and post-test isokinetic concentric and eccentric quadriceps and hamstring testing of both legs. Subjects completed 4 weeks of training on their respective treadmills with mileage increasing ½ mile each week, beginning with 2 miles. The C group did not participate in any training. The CR revealed a significant two way interaction of group x time with MT increasing (pre: 0.80 ± 0.09 to post: 0.84 ± 0.09), NMT decreasing (pre: 0.76 ± 0.13 to post: 0.74 ± 0.10), and C showing no change (pre: 0.79 ± 0.10 to post: 0.79 ± 0.09. The FR revealed a significant two way interaction of speed x sex with the FR increasing as speeds increased for men (60 degrees.s-1: 1.04 ± 0.11; 180 degrees.s-1: 1.66 ± 0.27; 300 degrees.s-1: 2.36 ± 0.45) and women (60 degrees.s-1: 1.05 ± 0.16; 180 degrees.s-1: 1.90 ± 0.26; 300 degrees.s-1: 2.75 ± 0.47) but women increased greater relative to men. Training mode elicited a specific change in concentric hamstring and quadriceps strength resulting in specific changes to the CR; however, neither training mode had an effect on eccentric hamstrings nor the FR. Special attention should be given to the mode of endurance training when the goal is to alter the hamstring/quadriceps CR. Key points Specificity of treadmill training had different effects on concentric strength. Specificity of treadmill training had little or no effect on eccentric strength. Conventional and functional strength ratios may give different results

  15. Quadriceps and Patient Reported Function in ACL Reconstructed Patients: A Principal Component Analysis.

    PubMed

    Norte, Grant E; Hertel, Jay N; Saliba, Susan A; Diduch, David R; Hart, Joseph M

    2017-07-17

    Assessment of physical function for individuals after ACL reconstruction (ACL-R) is complex and warrants the use of diverse evaluation strategies. To maximize the efficiency of assessment, there is a need to identify tests that provide the most meaningful information about this population. To investigate underlying constructs of quadriceps muscle function that uniquely describe aspects of performance in patients after ACL-R, and establish clinical thresholds for measures able to classify patients with and without ACL-R. Cross-sectional. Research laboratory. Patients (or Other Participants): 72 patients with a primary, unilateral ACL-R (32M/40F, age = 26.0 ± 9.3 years, time since surgery = 46.5 ± 58.0 months), and 30 healthy individuals (12M/18F, age = 22.7 ± 4.6 years). Quadriceps function was assessed bilaterally during one study visit. Isokinetic strength (peak torque, total work, average power) at 90° and 180°/second, maximal voluntary isometric contraction (MVIC) torque, fatigue index, central activation ratio (CAR), Hoffmann reflex (H:M ratio), and active motor threshold (AMT). Principal component analyses were performed for the involved limb, contralateral limb, and limb symmetry. Receiver-operator-characteristic curve analyses were conducted to determine the diagnostic utility of each variable. Binary logistic regression was used to predict group membership (ACL-R vs. Healthy). Three components of peripheral, central, and combined (peripheral and central) muscle function were identified, explaining 70.7-80.5% of variance among measures of quadriceps function. Total knee extensor work at 90°/sec (≥ 18.4 J/kg), AMT (≥ 39.5%), and CAR (≥ 94.7%) of the involved limb were strong predictors of patient status, and correctly classified 83.5% of patients with ACL-R (P < 0.001). Unique constructs of peripheral, central, and combined muscle function exist in ACL-R patients. Total knee extensor work at 90°/sec, AMT, and CAR consistently explained a

  16. Deficits in Quadriceps Strength and Patient-Oriented Outcomes at Return to Activity After ACL Reconstruction

    PubMed Central

    Lepley, Lindsey K.

    2015-01-01

    Context: Side-to-side quadriceps strength deficits are linked to hazardous lower extremity mechanics and reduced function at a time when individuals are returned to activity after anterior cruciate ligament (ACL) reconstruction. As a result, generalized criteria have emerged in the literature, wherein researchers are recommending that patients be cleared for participation once side-to-side differences in strength are ≤10% of the noninjured limb. Similar recommendations exist for patient-oriented outcomes (ie, self-reported function and hop tests), where deficits of ≤10% are considered ideal at return to activity. It is unclear how many studies actually achieve these clinically recommended results. Evidence Acquisition: Articles that reported quadriceps strength deficits as compared to the contralateral limb were collected from peer-reviewed sources available on Medline and Web of Science databases (1990 through August 2014). Search terms included the following: anterior cruciate ligament OR ACL AND muscle weakness, anterior cruciate ligament OR ACL AND strength; return-to-activity AND strength; anterior cruciate ligament OR ACL AND quadriceps. Study Design: Clinical review. Level of Evidence: Level 4. Results: Average side-to-side strength deficits at 6 months postreconstruction were 23% ± 8% (range, 3%-40%), while the average at 12 months postsurgery was found to be 14% ± 6% (range, 3%-28%). The average deficits in self-reported function at 6 months (mean, 14% ± 5%) and 12 months postsurgery (mean, 13% ± 6%) were also found to be >10%. Performance on hop tests was found to be less than optimal at 6 months postsurgery (mean, 11% ± 7%), but improved at 12 months postsurgery (mean, 1.3% ± 2%). Conclusion: This review provides an up-to-date account of the typical deficits in strength and patient-oriented outcomes that exist when formalized physical therapy concludes after ACL reconstruction. Based on the studies included, it seems pertinent that researchers

  17. Differences in Gait Performance, Quadriceps Strength, and Physical Activity Between Fallers and Nonfallers in Women with Osteoporosis.

    PubMed

    Stief, Felix; Schäfer, Anna; Vogt, Lutz; Kirchner, Marietta; Hübscher, Markus; Thiel, Christian; Banzer, Winfried; Meurer, Andrea

    2016-07-01

    The present study should reveal differences in gait performance, quadriceps strength, and physical activity (PA) between fallers and nonfallers in women with osteoporosis. Forty-one women with osteoporosis (17 fallers, 24 nonfallers) participated. Gait analysis shows that fallers were walking with a slower walking speed (-9%, p = .033) and had a shorter stride length (-7%, p = .039). Moreover, fallers showed a decreased ankle power generation (-18%, p = .045). The quadriceps strength was decreased by 24% for fallers (p = .005) while PA showed no significant differences. Although a decrease in ankle power generation could have an effect on floor clearance for limb advancement in the swing phase, the causal relationship between spatiotemporal parameters (walking speed, stride length) and walking ankle joint power generation remains unknown and warrants further investigation. In conclusion, walking speed, stride length, ankle power generation, and quadriceps strength can be used to differentiate between fallers and nonfallers in women with osteoporosis.

  18. Effects of transcutaneous electrical nerve stimulation and therapeutic exercise on quadriceps activation in people with tibiofemoral osteoarthritis.

    PubMed

    Pietrosimone, Brian G; Saliba, Susan A; Hart, Joseph M; Hertel, Jay; Kerrigan, D Casey; Ingersoll, Christopher D

    2011-01-01

    Blinded, randomized controlled trial. To determine if the combination of transcutaneous electrical nerve stimulation (TENS) set to a sensory level and therapeutic exercise would be more effective than the combination of placebo TENS and therapeutic exercises or therapeutic exercises only to increase quadriceps activation in individuals with tibiofemoral osteoarthritis. Quadriceps activation deficits are common in those with tibiofemoral osteoarthritis, and TENS has been reported to immediately increase quadriceps activation. Yet the long-term benefits of TENS for motor neuron activation have yet to be determined. Thirty-six individuals with radiographically assessed tibiofemoral osteoarthritis were randomly assigned to the TENS and exercise, placebo and exercise, and exercise only groups. All participants completed a supervised 4-week lower extremity exercise program. TENS and placebo TENS were worn throughout the therapeutic exercise sessions, as well as during daily activities. Our primary outcome measures, quadriceps central activation ratio, and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were evaluated at baseline and at 2 weeks and 4 weeks of the intervention. Quadriceps activation was significantly higher in the TENS with exercise group compared to the exercise only group at 2 weeks (0.94 ± 0.04 versus 0.82 ± 0.12, P<.05) and the placebo and exercise group at 4 weeks (0.94 ± 0.06 versus 0.81 ± 0.15, P<.05). WOMAC scores improved in all 3 groups over time, with no significant differences among groups. This study provides evidence that TENS applied in conjunction with therapeutic exercise and daily activities increases quadriceps activation in patients with tibiofemoral osteoarthritis and, while function improved for all participants, effects were greatest in the group treated with a combination of TENS and therapeutic exercises. Therapy, level 1b-.

  19. Effect of eccentric exercise-induced muscle damage on electromyographyic activity of quadriceps in untrained healthy females.

    PubMed

    Rezaei, Mandana; Ebrahimi-Takamjani, Ismael; Jamshidi, Ali A; Vassaghi-Gharamaleki, Behnoush; Hedayatpour, Nosratollah; Havaei, Naser

    2014-01-01

    The aim of this study was to investigate muscle damage indicators and electromyography activities of quadriceps muscles at 25° of hip flexion in untrained healthy females after an eccentric exercise induced muscle fiber damage. A total of 14 healthy females participated in this pre-experimental study. The subjects performed maximal eccentric quadriceps contractions at 25˚ of hip flexion. Maximum voluntary extensor isometric and concentric moments, angle of maximum moment for concentric contractions, perceived pain intensity, and pain pressure threshold were examined before, immediately, 48 hours, 120 hours and 14 days after eccentric exercise. Additionally, electromyography of three parts of quadriceps muscle, knee flexion range of motion and thigh circumference were measured before and after eccentric exercise. Significant reductions in maximum isometric moment and maximum concentric moment were observed at angular velocity of 60˚ per sec immediately after eccentric exercise (p<0.05). Both maximum isometric moment and maximum concentric moment recovered to the baseline 48 hours after eccentric exercise. Increased pain intensity and decreased knee joint range of motion manifested 48 hours after eccentric exercise. Pain pressure threshold for the quadriceps was higher 14 days after exercise as compared to 48 and 120 hours (p<0.05). No significant changes observed in electromyography and thigh circumference (p>0.05). Eccentric exercise performed at 25˚ of hip flexion resulted in muscle fiber injuries within the quadriceps muscle. However, electromyography of quadriceps muscle was not significantly different than the baseline. The result indicates that hip joint position may modify the effect of eccentric exercise on muscle activation.

  20. Effect of eccentric exercise-induced muscle damage on electromyographyic activity of quadriceps in untrained healthy females

    PubMed Central

    Rezaei, Mandana; Ebrahimi-Takamjani, Ismael; Jamshidi, Ali A.; Vassaghi-Gharamaleki, Behnoush; Hedayatpour, Nosratollah; Havaei, Naser

    2014-01-01

    Background: The aim of this study was to investigate muscle damage indicators and electromyography activities of quadriceps muscles at 25° of hip flexion in untrained healthy females after an eccentric exercise induced muscle fiber damage. Methods: A total of 14 healthy females participated in this pre-experimental study. The subjects performed maximal eccentric quadriceps contractions at 25˚ of hip flexion. Maximum voluntary extensor isometric and concentric moments, angle of maximum moment for concentric contractions, perceived pain intensity, and pain pressure threshold were examined before, immediately, 48 hours, 120 hours and 14 days after eccentric exercise. Additionally, electromyography of three parts of quadriceps muscle, knee flexion range of motion and thigh circumference were measured before and after eccentric exercise. Results: Significant reductions in maximum isometric moment and maximum concentric moment were observed at angular velocity of 60˚ per sec immediately after eccentric exercise (p<0.05). Both maximum isometric moment and maximum concentric moment recovered to the baseline 48 hours after eccentric exercise. Increased pain intensity and decreased knee joint range of motion manifested 48 hours after eccentric exercise. Pain pressure threshold for the quadriceps was higher 14 days after exercise as compared to 48 and 120 hours (p<0.05). No significant changes observed in electromyography and thigh circumference (p>0.05). Conclusion: Eccentric exercise performed at 25˚ of hip flexion resulted in muscle fiber injuries within the quadriceps muscle. However, electromyography of quadriceps muscle was not significantly different than the baseline. The result indicates that hip joint position may modify the effect of eccentric exercise on muscle activation. PMID:25695012

  1. GNE mutations in an American family with quadriceps-sparing IBM and lack of mutations in s-IBM.

    PubMed

    Vasconcelos, Olavo M; Raju, Raghavan; Dalakas, Marinos C

    2002-12-10

    Analysis for GNE mutations was performed in an American, non-Iranian Jewish, family with quadriceps-sparing inclusion body myopathy (QS-IBM) and in 11 patients with sporadic IBM (s-IBM). Two novel nonallosteric site missense mutations were found in the QS-IBM kinship. No mutations were identified in s-IBM patients. After 8 years of follow-up and severe disease progression, the quadriceps muscle in the QS-IBM patient remains strong despite subclinical involvement documented with repeat MRI and muscle biopsy.

  2. Floating patella: combined quadriceps tendon, retinacula, and patellar tendon ruptures in a high-performance elite athlete.

    PubMed

    Langer, Phillip R; Selesnick, F Harlan

    2010-09-01

    Simultaneous quadriceps and patellar tendon rupture is rare. To our knowledge, we present the first known case of simultaneous quadriceps tendon, patella tendon, and retinacula rupture in the ipsilateral knee of a high-performance elite athlete. This disabling injury in the active person results in an inability to actively obtain and maintain full knee extension. When the tendons do not heal properly, at the correct length and tension, knee range of motion and strength can become significantly altered, leading to early fatigue, patellofemoral pain, and possibly instability, preventing return to preinjury status. Immediate surgical repair is recommended for optimal return of knee function and power.

  3. Quadriceps activation and perceived exertion during a high intensity, steady state contraction to failure.

    PubMed

    Pincivero, D M; Gear, W S

    2000-04-01

    The ability to sustain a high-intensity, steady-state muscle contraction may have differential effects on neuromuscular activation and perceived exertion. The purpose of this study was to examine changes in neuromuscular activation and perceived exertion at a near-maximal steady-state contraction of the quadriceps in healthy men. Seventeen healthy, college-aged male volunteers were studied during isometric contractions equivalent to 80% of the maximum voluntary contraction (MVC). Perceived exertion was measured with a modified category-ratio scale (CR-10). The CR-10 scale was anchored with one high anchor at 100% MVC and one low anchor at 10% MVC. Subjects then performed an 80% MVC for as long as they could sustain it. Subjects were asked to rate the feelings in their quadriceps every 5 s during the contraction. The results demonstrated significant increases in neuromuscular activation of the vastus medialis and vastus lateralis muscles (P < 0.05) during the 80% MVC, but there were no significant muscle by time interactions. The results also demonstrated a significant increase (P < 0.05) in perceived exertion during the 80% MVC. Neuromuscular activation of both muscles, and perceived exertion, were found to increase in linear (P < 0.05) and quadratic (P < 0.05) trends. Alterations in motor unit discharge properties or impairments in muscle fiber membrane excitability may account for nonlinear increases in vastii muscle activation and perceived exertion.

  4. Effective therapy of transected quadriceps muscle in rat: Gastric pentadecapeptide BPC 157.

    PubMed

    Staresinic, Mario; Petrovic, Igor; Novinscak, Tomislav; Jukic, Ivana; Pevec, Damira; Suknaic, Slaven; Kokic, Neven; Batelja, Lovorka; Brcic, Luka; Boban-Blagaic, Alenka; Zoric, Zdenka; Ivanovic, Domagoj; Ajduk, Marko; Sebecic, Bozidar; Patrlj, Leonardo; Sosa, Tomislav; Buljat, Gojko; Anic, Tomislav; Seiwerth, Sven; Sikiric, Predrag

    2006-05-01

    We report complete transection of major muscle and the systemic peptide treatment that induces healing of quadriceps muscle promptly and then maintains the healing with functional restoration. Initially, stable gastric pentadecapeptide BPC 157 (GEPPPGKPADDAGLV, M.W. 1419, PL-10, PLD-116, PL 14736 Pliva, Croatia; in trials for inflammatory bowel disease; wound treatment; no toxicity reported; effective alone without carrier) also superiorly accelerates the healing of transected Achilles tendon. Regularly, quadriceps muscle completely transected transversely 1.0 cm proximal to patella presents a definitive defect that cannot be compensated in rat. BPC 157 (10 microg, 10 ng, 10 pg/kg) is given intraperitoneally, once daily; the first application 30 min posttransection, the final 24 h before sacrifice. It consistently improves muscle healing throughout the whole 72-day period. Improved are: (i) biomechanic (load of failure increased); (ii) function (walking recovery and extensor postural thrust/motor function index returned toward normal healthy values); (iii) microscopy/immunochemistry [i.e., mostly muscle fibers connect muscle segments; absent gap; significant desmin positivity for ongoing regeneration of muscle; larger myofibril diameters on both sides, distal and proximal (normal healthy rat-values reached)]; (iv) macroscopic presentation (stumps connected; subsequently, atrophy markedly attenuated; finally, presentation close to normal noninjured muscle, no postsurgery leg contracture). Thus, posttransection healing-consistently improved-may suggest this peptide therapeutic application in muscle disorders.

  5. Effect of endurance versus resistance training on quadriceps muscle dysfunction in COPD: a pilot study

    PubMed Central

    Iepsen, Ulrik Winning; Munch, Gregers Druedal Wibe; Rugbjerg, Mette; Rinnov, Anders Rasmussen; Zacho, Morten; Mortensen, Stefan Peter; Secher, Niels H; Ringbaek, Thomas; Pedersen, Bente Klarlund; Hellsten, Ylva; Lange, Peter; Thaning, Pia

    2016-01-01

    Introduction Exercise is an important countermeasure to limb muscle dysfunction in COPD. The two major training modalities in COPD rehabilitation, endurance training (ET) and resistance training (RT), may both be efficient in improving muscle strength, exercise capacity, and health-related quality of life, but the effects on quadriceps muscle characteristics have not been thoroughly described. Methods Thirty COPD patients (forced expiratory volume in 1 second: 56% of predicted, standard deviation [SD] 14) were randomized to 8 weeks of ET or RT. Vastus lateralis muscle biopsies were obtained before and after the training intervention to assess muscle morphology and metabolic and angiogenic factors. Symptom burden, exercise capacity (6-minute walking and cycle ergometer tests), and vascular function were also assessed. Results Both training modalities improved symptom burden and exercise capacity with no difference between the two groups. The mean (SD) proportion of glycolytic type IIa muscle fibers was reduced after ET (from 48% [SD 11] to 42% [SD 10], P<0.05), whereas there was no significant change in muscle fiber distribution with RT. There was no effect of either training modality on muscle capillarization, angiogenic factors, or vascular function. After ET the muscle protein content of phosphofructokinase was reduced (P<0.05) and the citrate synthase content tended increase (P=0.08) but no change was observed after RT. Conclusion Although both ET and RT improve symptoms and exercise capacity, ET induces a more oxidative quadriceps muscle phenotype, counteracting muscle dysfunction in COPD. PMID:27822028

  6. Quadriceps Contusion

    MedlinePlus

    ... And they can happen in sports like skateboarding, skiing, and snowboarding, where there is a chance your thigh might ... t do it to an opposing player. With skiing, snowboarding, and skateboarding, know your limits. Stay within ...

  7. Quadriceps Contusion

    MedlinePlus

    ... bending your knee and walking without crutches. The range of motion of your knee will be less than 45 ... to bend your knee to see if your range of motion is limited. If the injury seems serious or ...

  8. Effects of sodium chloride, phosphate type and concentration, and pump rate on beef biceps femoris quality and sensory characteristics.

    PubMed

    Baublits, R T; Pohlman, F W; Brown, A H; Johnson, Z B

    2005-06-01

    Beef biceps femoris muscles (n=45) were used to evaluate the effect of enhancement with solutions comprising 2.0% sodium chloride and either sodium hexametaphosphate (SHMP), sodium tripolyphosphate (STPP), or tetrasodium pyrophosphate (TSPP) at either 0.2% or 0.4% of product weight. All solutions were injected into muscle samples at either 112% (12% pump) or 118% (18% pump) of raw product weight. Muscles treated with all three phosphate types had decreased (P<0.05) free water compared to untreated muscles (CNT), and while TSPP-treated muscles were able to bind greater (P<0.05) additional water than CNT, STPP- and SHMP-treated muscles did not differ (P>0.05) from CNT. Disregarding phosphate type, steaks with 0.4% phosphate inclusion bound more (P<0.05) water than those with 0.2% phosphate inclusion. Steaks treated with STPP or TSPP had decreased (P<0.05) cooking losses than CNT, while SHMP-treated steaks did not differ (P>0.05) from CNT. Steaks injected at 18% pump had greater (P<0.05) percent moisture, and did not differ (P>0.05) in free water, water binding, or cooking losses from steaks injected at 12% pump. Although there were no differences (P>0.05) in Warner-Bratzler shear force in this study, steaks with SHMP, STPP, and TSPP all were rated more tender, and juicier (P<0.05) by sensory panelists than CNT steaks or steaks enhanced only with sodium chloride. Regardless of phosphate type, steaks enhanced with 0.4% phosphate and those steaks at 18% pump received improved (P<0.05) sensory tenderness ratings compared to 0.2% phosphate and 12% pump, respectively. These results suggest that enhancing biceps femoris muscles with STPP or TSPP can improve water retention, yield, and palatability characteristics. Additionally, enhancement with a phosphate/salt solution at an 18% pump rate, compared to a 12% pump rate, can allow for improved sensory tenderness perceptions without decreasing product yields.

  9. Selective lengthening of the psoas and rectus femoris and preservation of the iliacus for flexion deformity of the hip in cerebral palsy patients.

    PubMed

    Matsuo, T; Hara, H; Tada, S

    1987-01-01

    Between 1978 and 1983, 52 Japanese patients with cerebral palsy underwent operative correction of flexion deformity of the hip. The results of lengthening of the psoas, rectus femoris, and proximal hamstrings were satisfactory. The iliacus was left intact. Improvement in gait and activities of daily living was attained. Concentric reduction was obtained in 27 of 33 dislocated or subluxated hips. Sitting and perineal care were facilitated, and pain was alleviated. We conclude that preservation of the iliacus is important.

  10. Clinical Experience With the Combination of a Biceps Femoris Muscle Turnover Flap and a Posterior Thigh Fasciocutaneous Hatchet Flap for the Reconstruction of Ischial Pressure Ulcers.

    PubMed

    Demirseren, Mustafa Erol; Ceran, Candemir; Aksam, Berrak; Demiralp, Cemil Ozerk

    2016-01-01

    The reconstruction of ischial pressure ulcers is problematic because of the distinctive anatomical properties of the region and high recurrence rates. To date, no single technique has been proven to be effective in reducing recurrence of the ulcers. We present our experience with the combination of a biceps femoris muscle turnover flap and a posterior thigh fasciocutaneous hatchet flap and discuss the long-term results. A retrospective clinical analysis of 15 patients with grade 4 ischial pressure ulcers reconstructed with biceps femoris muscle turnover flaps and laterally based posterior thigh fasciocutaneous hatchet flaps was carried out between January 2010 and January 2013. Debridement and reconstruction of the ulcers were accomplished in a single stage. The posterior thigh fasciocutaneous flap was elevated in a hatchet style. The long and/or short head of the biceps femoris muscle were dissected from their insertions, turned over on their major pedicles, and their distal portions were used to obliterate the cavitary defect. The skin defect over the muscles was covered by the fasciocutaneous hatchet flap. The average age of the patients was 42.6 years and the mean follow-up time was 27.2 months. Three patients had the following early postoperative complications: hematoma, suture dehiscence, and the necrosis of the short head of biceps muscle. Only 1 patient had a recurrent ulcer 15 months after surgery, which was treated with debridement and the readvancement of the fasciocutaneous flap. The overall recurrence rate was 6.6%. The biceps femoris muscle turnover flap combined with the posterior thigh fasciocutaneous hatchet flap is a worthwhile option to consider for the reconstruction of ischial pressure ulcers and this technique produces favorable results in terms of the lack of recurrence and complications. The use of the muscle and fasciocutaneous tissue as 2 different flaps, which have different roles in the early and late postoperative period, reduces the

  11. Acute effects of anterior thigh foam rolling on hip angle, knee angle, and rectus femoris length in the modified Thomas test.

    PubMed

    Vigotsky, Andrew D; Lehman, Gregory J; Contreras, Bret; Beardsley, Chris; Chung, Bryan; Feser, Erin H

    2015-01-01

    Background. Foam rolling has been shown to acutely increase range of motion (ROM) during knee flexion and hip flexion with the experimenter applying an external force, yet no study to date has measured hip extensibility as a result of foam rolling with controlled knee flexion and hip extension moments. The purpose of this study was to investigate the acute effects of foam rolling on hip extension, knee flexion, and rectus femoris length during the modified Thomas test. Methods. Twenty-three healthy participants (male = 7; female = 16; age = 22 ± 3.3 years; height = 170 ± 9.18 cm; mass = 67.7 ± 14.9 kg) performed two, one-minute bouts of foam rolling applied to the anterior thigh. Hip extension and knee flexion were measured via motion capture before and after the foam rolling intervention, from which rectus femoris length was calculated. Results. Although the increase in hip extension (change = +1.86° (+0.11, +3.61); z(22) = 2.08; p = 0.0372; Pearson's r = 0.43 (0.02, 0.72)) was not due to chance alone, it cannot be said that the observed changes in knee flexion (change = -1.39° (-5.53, +2.75); t(22) = -0.70; p = 0.4933; Cohen's d = - 0.15 (-0.58, 0.29)) or rectus femoris length (change = -0.005 (-0.013, +0.003); t(22) = -1.30; p = 0.2070; Cohen's d = - 0.27 (-0.70, 0.16)) were not due to chance alone. Conclusions. Although a small change in hip extension was observed, no changes in knee flexion or rectus femoris length were observed. From these data, it appears unlikely that foam rolling applied to the anterior thigh will improve passive hip extension and knee flexion ROM, especially if performed in combination with a dynamic stretching protocol.

  12. Comparison of Lower Body Specific Resistance Training on the Hamstring to Quadriceps Strength Ratios in Men and Women

    ERIC Educational Resources Information Center

    Dorgo, Sandor; Edupuganti, Pradeep; Smith, Darla R.; Ortiz, Melchor

    2012-01-01

    In this study, we compared hamstring (H) and quadriceps (Q) strength changes in men and women, as well as changes in conventional and functional H:Q ratios following an identical 12-week resistance training program. An isokinetic dynamometer was used to assess 14 male and 14 female participants before and after the intervention, and conventional…

  13. Effect of a Periodized Power Training Program on the Functional Performances and Contractile Properties of the Quadriceps in Sprinters

    ERIC Educational Resources Information Center

    Kamandulis, Sigitas; Skurvydas, Albertas; Brazaitis, Marius; Stanislovaitis, Aleksas; Duchateau, Jacques; Stanislovaitiene, Jurate

    2012-01-01

    Our purpose was to compare the effect of a periodized preparation consisting of power endurance training and high-intensity power training on the contractile properties of the quadriceps muscle and functional performances in well trained male sprinters (n = 7). After 4 weeks of high-intensity power training, 60-m sprint running time improved by an…

  14. Comparison of Lower Body Specific Resistance Training on the Hamstring to Quadriceps Strength Ratios in Men and Women

    ERIC Educational Resources Information Center

    Dorgo, Sandor; Edupuganti, Pradeep; Smith, Darla R.; Ortiz, Melchor

    2012-01-01

    In this study, we compared hamstring (H) and quadriceps (Q) strength changes in men and women, as well as changes in conventional and functional H:Q ratios following an identical 12-week resistance training program. An isokinetic dynamometer was used to assess 14 male and 14 female participants before and after the intervention, and conventional…

  15. Neglected rupture of the quadriceps tendon in a patient with chronic renal failure (case report and review of the literature).

    PubMed

    Hassani, Zouhir Ameziane; Boufettal, Moncef; Mahfoud, Moustapha; Elyaacoubi, Moradh

    2014-01-01

    Spontaneous ruptures of the quadriceps tendon are infrequent injuries, it is seen primarily in patients with predisposing diseases such as gout, rheumatoid arthritis and chronic renal failure. A 32-year-old man had a history of end stage renal disease and received regular hemodialysis treatment for more than 5 years. He was admitted in our service for total functional impotence of the right lower limb with knee pain after a common fall two months ago. The radiogram showed a ''patella baja" with suprapatellar calcifications. The ultrasound and MRI showed an aspect of rupture of the quadriceps tendon in its proximal end with retraction of 3 cm. Quadriceps tendon repair was performed with a lengthening plasty, and the result was satisfactory after a serial rehabilitation program. The diagnosis of quadriceps tendon ruptures needs more attention in patients with predisposing diseases. They should not be unknown because the treatment of neglected lesions is more difficult. We insist on the early surgical repair associated with early rehabilitation that can guarantee recovery of good active extension.

  16. Effect of Electromyographic Biofeedback Training on Pain, Quadriceps Muscle Strength, and Functional Ability in Juvenile Rheumatoid Arthritis.

    PubMed

    Eid, Mohamed Ahmed Mahmoud; Aly, Sobhy M; El-Shamy, Shamekh M

    2016-12-01

    To investigate the effects of electromyographic (EMG) biofeedback training on pain, quadriceps strength, and functional ability in juvenile rheumatoid arthritis (JRA). This is a randomized controlled study; 36 children (11 boys and 25 girls) with polyarticular JRA, with ages ranging from 8 to 13 years, were selected and assigned randomly, using computer-generated random numbers, into 2 groups. The control group (n = 18) received the conventional physical therapy program, whereas the study group (n = 18) received the same program as the control group in addition to EMG biofeedback-guided isometric exercises for 3 days a week for 12 weeks. Pain, peak torque of quadriceps strength, and functional ability were evaluated before, after 6 weeks, and at the end of 12 weeks of the treatment program. By 6 weeks, significant differences were observed in the study group (P < 0.05) in all measured variables except pain levels, whereas nonsignificant differences were observed in all measured variables in the control group. By 12 weeks, each group demonstrated significant improvements in pain, quadriceps strength, and functional ability (P < 0.05), with significantly greater improvements seen in the study group compared to the control group (P < 0.05). Both groups showed significant improvement at 12 weeks compared to that at 6 weeks. Electromyographic biofeedback may be a useful intervention modality to reduce pain, improve quadriceps strength, and functional performance in JRA.

  17. Real-time sonoelastography of the patellar and quadriceps tendons: pattern description in professional athletes and healthy volunteers.

    PubMed

    Ozcan, Ayse Nur Sirin; Tan, Sinan; Tangal, Nuray Gulden; Cıracı, Saliha; Kudas, Savas; Bektaser, Suleyman Bulent; Arslan, Halil

    2016-09-01

    The comparison of elastographic features of quadriceps and patellar tendons in a group of professional athletes and healthy volunteers and the description of elasticity characteristics of these tendons. Thirty-nine professional athletes (22 male, 17 female; mean age 18.5 years) and 35 healthy volunteers (21 male, 14 female; mean age 19 years) were included. They were divided into two groups by gender. Quadriceps tendon, patellar side of the patellar tendon, and tibial side of the patellar tendon elasticity patterns and strain ratios were investigated with real-time ultrasound elastography. The elasticity features of the dominant leg and non-dominant leg of athletes and volunteers legs were compared. In addition quadriceps and patellar tendons were compared separately for three distinct tendon locations. There was no difference between the athletes and the healthy volunteers and also between the dominant leg and non-dominant leg of athletes. At tendon comparison, the quadriceps tendon was harder than the patellar tendon at both side and patellar side of patellar tendon was found to be stiffer than the tibial side of patellar tendon. Although biomechanical studies showed that tendon stiffness increased after long exercise, no significant difference was found between athletes' and healthy volunteers' tendon elasticity. These three tendon locations exhibit different elasticity features and the knowledge of the elasticity feature will be useful in assessing tendon pathologies.

  18. Effect of a Periodized Power Training Program on the Functional Performances and Contractile Properties of the Quadriceps in Sprinters

    ERIC Educational Resources Information Center

    Kamandulis, Sigitas; Skurvydas, Albertas; Brazaitis, Marius; Stanislovaitis, Aleksas; Duchateau, Jacques; Stanislovaitiene, Jurate

    2012-01-01

    Our purpose was to compare the effect of a periodized preparation consisting of power endurance training and high-intensity power training on the contractile properties of the quadriceps muscle and functional performances in well trained male sprinters (n = 7). After 4 weeks of high-intensity power training, 60-m sprint running time improved by an…

  19. Physiotherapy, including quadriceps exercises and patellar taping, for knee osteoarthritis with predominant patello-femoral joint involvement: randomized controlled trial.

    PubMed

    Quilty, Brian; Tucker, Marian; Campbell, Rona; Dieppe, Paul

    2003-06-01

    To design and carry out a randomized controlled trial of a complex, physical therapy based intervention for patello-femoral joint (PFJ) osteoarthritis (OA) of the knee, examining medium to longterm outcomes. The participants, who had knee pain and predominant PFJ OA, were recruited from a large population based study. The study design was a controlled trial using prerandomization and a blind observer, comparing the intervention package with standard nonphysiotherapy treatment. The physiotherapy intervention was delivered in local community health centers and clinics and comprised education, quadriceps and functional exercises, and patellar taping delivered by a single physiotherapist in nine 30-minute sessions over 10 weeks, with advice to continue thereafter. The outcome measures were pain in the worse knee by 100 mm visual analog scale score, the disability domain of the Western Ontario and McMaster University OA index (WOMAC), and quadriceps muscle strength by maximum voluntary contraction. Eighty-seven patients were recruited to the study, 43 were randomized to the treatment arm. At 5 months post-baseline (10 weeks post-treatment) the treatment group had a small decrease in pain and a significant increase in quadriceps strength of the index knee. After one year there were no significant differences in any outcome measure, most of which had returned towards pretreatment levels. The treatment package produced small improvements in knee pain scores and quadriceps muscle strength 10 weeks after the end of the treatment period. There was no difference between the 2 groups at 12 months.

  20. Assessement of quadriceps strength, endurance and fatigue in FSHD and CMT: benefits and limits of femoral nerve magnetic stimulation.

    PubMed

    Bachasson, D; Temesi, J; Bankole, C; Lagrange, E; Boutte, C; Millet, G Y; Verges, S; Levy, P; Feasson, L; Wuyam, B

    2014-02-01

    To (i) evaluate the feasibility and the reliability of a test assessing quadriceps strength, endurance and fatigue in patients with fascioscapulohumeral dystrophy (FSHD) and Charcot-Marie-Tooth disease (CMT), (ii) compare quadriceps function between patients and healthy controls. Controls performed the test once and patients twice on two separate visits. It involved progressive sets of 10 isometric contractions each followed by neuromuscular assessments with FNMS. Volitional assessment of muscle strength, endurance and fatigue appeared to be reliable in FSHD and CMT patients. Supramaximal FNMS was achieved in ∼70% of FSHD patients and in no CMT patients. In FSHD patients, Femoral nerve magnetic stimulation (FNMS) provided reliable assessment of central (typical error as a coefficient of variation (CVTE)<8% for voluntary activation) and peripheral (CVTE<10% and intraclass coefficient correlation >0.85 for evoked responses) function. Patients and controls had similar reductions in evoked quadriceps responses, voluntary activation and similar endurance. This test provides reliable evaluation but FNMS exhibits limitations due to insufficient stimulation intensity particularly in neurogenic conditions. It showed similar central and peripheral quadriceps fatigability in patients and controls. This test may be a valuable tool for patient follow-up although further development of magnetic stimulation devices is needed to extend its applicability. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  1. Development of estimation system of knee extension strength using image features in ultrasound images of rectus femoris

    NASA Astrophysics Data System (ADS)

    Murakami, Hiroki; Watanabe, Tsuneo; Fukuoka, Daisuke; Terabayashi, Nobuo; Hara, Takeshi; Muramatsu, Chisako; Fujita, Hiroshi

    2016-04-01

    The word "Locomotive syndrome" has been proposed to describe the state of requiring care by musculoskeletal disorders and its high-risk condition. Reduction of the knee extension strength is cited as one of the risk factors, and the accurate measurement of the strength is needed for the evaluation. The measurement of knee extension strength using a dynamometer is one of the most direct and quantitative methods. This study aims to develop a system for measuring the knee extension strength using the ultrasound images of the rectus femoris muscles obtained with non-invasive ultrasonic diagnostic equipment. First, we extract the muscle area from the ultrasound images and determine the image features, such as the thickness of the muscle. We combine these features and physical features, such as the patient's height, and build a regression model of the knee extension strength from training data. We have developed a system for estimating the knee extension strength by applying the regression model to the features obtained from test data. Using the test data of 168 cases, correlation coefficient value between the measured values and estimated values was 0.82. This result suggests that this system can estimate knee extension strength with high accuracy.

  2. The changes in springbok (Antidorcas marsupialis) Longissimus thoracis et lumborum and Biceps femoris muscles during the rigour period.

    PubMed

    North, M K; Frylinck, L; Hoffman, L C

    2016-02-01

    This study describes the changes taking place during rigour in springbok (Antidorcas marsupialis) Longissimus thoracis et lumborum (LTL) and Biceps femoris (BF) muscles. Samples from six male and six female springbok were snap-frozen at 2, 3, 5, 8, 12, 18, 24 and 30h post-mortem (PM) and the pH, calpains I, II and calpastatin activities and cathepsins B, BL and H activities were determined. The temperature was also recorded. Significant third-order interactions were found for the pH and temperature, with the female LTL cooling more rapidly and acidifying slower than the other samples. Female muscles were at risk of developing cold-shortening and all the samples cooled more rapidly than recommended for cattle or sheep. Cathepsin BL activity increased PM, likely due to the degradation of the lysosomes. Calpains I, II and calpastatin activity declined during rigour, indicating that the calpains were activated early PM. Gender and muscle had a significant effect on calpain and cathepsin activity.

  3. Neuromuscular efficiency of the vastus lateralis and biceps femoris muscles in individuals with anterior cruciate ligament injuries☆

    PubMed Central

    Aragão, Fernando Amâncio; Schäfer, Gabriel Santo; de Albuquerque, Carlos Eduardo; Vituri, Rogério Fonseca; de Azevedo, Fábio Mícolis; Bertolini, Gladson Ricardo Flor

    2015-01-01

    Objective To analyze strength and integrated electromyography (IEMG) data in order to determine the neuromuscular efficiency (NME) of the vastus lateralis (VL) and biceps femoris (BF) muscles in patients with anterior cruciate ligament (ACL) injuries, during the preoperative and postoperative periods; and to compare the injured limb at these two times, using the non-operated limb as a control. Methods EMG data and BF and VL strength data were collected during three maximum isometric contractions in knee flexion and extension movements. The assessment protocol was applied before the operation and two months after the operation, and the NME of the BF and VL muscles was obtained. Results There was no difference in the NME of the VL muscle from before to after the operation. On the other hand, the NME of the BF in the non-operated limb was found to have increased, two months after the surgery. Conclusions The NME provides a good estimate of muscle function because it is directly related to muscle strength and capacity for activation. However, the results indicated that two months after the ACL reconstruction procedure, at the time when loading in the open kinetic chain within rehabilitation protocols is usually started, the neuromuscular efficiency of the VL and BF had still not been reestablished. PMID:26229914

  4. The physical and biochemical changes in springbok (Antidorcas marsupialis) Longissimus thoracis et lumborum and Biceps femoris muscle during ageing.

    PubMed

    North, M K; Frylinck, L; Hoffman, L C

    2015-12-01

    This study aimed to determine the optimum ageing period for vacuum-packed springbok (Antidorcas marsupialis) Longissimus thoracis et lumborum (LTL) and Biceps femoris (BF) muscle stored at 5.4 ± 1.0°C. Portions of muscle from seven male and six female springbok were aged 1, 2, 5, 8, 14 or 21 days. The Warner Bratzler shear force declined most during the first five days post-mortem (PM), while purge and cooking losses increased significantly with ageing. Calpains I and II and calpastatin activity declined significantly up to five days PM, suggesting that they may be responsible for tenderization. Cathepsins B, BL and H activity increased significantly during ageing. The BF muscle had significantly higher pH, lower purge loss, higher cooking loss, higher WBSF and higher calpain and calpastatin activity than the LTL. No significant differences between the genders or muscles were found for the collagen content or collagen solubility. Springbok LTL and BF muscles should not be aged for longer than five days.

  5. Contraction history affects the in vivo quadriceps torque-velocity relationship in humans.

    PubMed

    Rácz, Levente; Béres, Sándor; Hortobágyi, Tibor; Tihanyi, József

    2002-08-01

    We hypothesized that the history of contraction would affect the in vivo quadriceps torque-velocity relationship. We examined the quadriceps torque-velocity relationship of the human knee extensors at the descending and ascending limb of the torque-position relationship by initiating the knee extension at a knee angle position of 1.39 rad (80 degrees ) or 0.87 rad (50 degrees ) over a 0.52 rad (30 degrees ) range of motion under conditions of constant or linearly increasing velocity. Maximal voluntary isometric knee extension torque (M(0)) was measured at 1.87 rad, 0.87 rad, and 0.35 rad, and concentric torque was measured. The subjects carried out ten maximal knee extensions at ten distinct velocities, each velocity ranging between 0.52 rad x s(-1) to 5.24 rad x s(-1) in steps of 0.52 rad x s(-1). Peak concentric torque was measured and mean torque calculated from the respective torque-time curves. Peak or mean torque, computed from the individual torque-time curves, and velocity data were fitted to the Hill equation under the four experimental conditions and the curve parameters computed. The M(0) was similar at 0.87 rad and 1.39 rad, but it was significantly lower at 0.35 rad. In the low-velocity domain of the torque-velocity curve where a plateau normally occurs, peak torque was always lower than M(0). Peak and mean torque were significantly greater under linearly increasing velocity conditions and the 1.39 rad starting knee position. Mean torque but not peak torque data could be well fitted to the Hill equation and the two computations resulted in significantly different Hill curve parameters including the concavity ratio, peak power, and maximal angular velocity. We concluded that the history of contraction significantly modifies the in vivo torque-velocity relationship of the human quadriceps muscle. Muscle mechanics and not neural factors may have accounted for the inconsistencies in the human torque-velocity relationships reported previously.

  6. Prevalence of abnormal patellofemoral congruence in elite American football players and association with quadriceps isokinetic testing.

    PubMed

    Brown, Christopher A; Carragee, Cat; Sox-Harris, Alex; Merchant, Alan C; Mcadams, Timothy R

    2014-02-01

    Abnormal patellofemoral joint alignment has been discussed as a potential risk factor for patellofemoral disorders and can impact the longevity of any elite athlete's career. The prevalence of abnormal patellofemoral congruence in elite American football athletes is similar to the general population and does not have a relationship with quadriceps isokinetic testing. A total of 125 athletes (220 knees) from the 2011 National Football League (NFL) Combine database who had radiographic and isokinetic studies were reviewed. Congruence angles (CA) and lateral patellofemoral angles (LPA) were calculated on a Merchant radiographic view. Isokinetic testing was used to determine quadriceps-to-hamstring strength (Q/H) ratio and side-to-side deficits. The relationships between abnormal CA and LPA with Q/H ratios, side-to-side deficits, and body mass index (BMI) were examined in separate logistic regression models. A Chi-square test was used to examine the association between CA and player position. Of all, 26.8% of the knees (95% CI: 21.1-33.2%) had an abnormal CA. Knees with normal CA (n = 161) did not significantly differ from those with an abnormal CA (n  = 59) in Q/H ratios (mean: 0.699 vs. 0.728, p = 0.19) or side-to-side quadriceps deficits (mean: 4.0 vs. 1.24, p  = 0.45). For each point increase in BMI, the odds ratio (OR) of abnormal congruence increased by 11.4% (p = 0.002). Of all the knees, 4.1% (95% CI: 1.9-7.6%) had an abnormal LPA, and this was not associated with Q/H ratios (p  =  0.13). For each point increase in BMI, the odds of abnormal LPA increased by 16% (p  = 0.036). CA abnormality had much higher odds of having an abnormal LPA (OR: 5.96, p = 0.014). We found that abnormal patellofemoral radiographic alignment in elite American football players is relatively common and there was no association with isokinetic testing. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  7. Reliability of the Q Force; a mobile instrument for measuring isometric quadriceps muscle strength.

    PubMed

    Douma, K W; Regterschot, G R H; Krijnen, W P; Slager, G E C; van der Schans, C P; Zijlstra, W

    2016-01-01

    The ability to generate muscle strength is a pre-requisite for all human movement. Decreased quadriceps muscle strength is frequently observed in older adults and is associated with a decreased performance and activity limitations. To quantify the quadriceps muscle strength and to monitor changes over time, instruments and procedures with a sufficient reliability are needed. The Q Force is an innovative mobile muscle strength measurement instrument suitable to measure in various degrees of extension. Measurements between 110 and 130° extension present the highest values and the most significant increase after training. The objective of this study is to determine the test-retest reliability of muscle strength measurements by the Q Force in older adults in 110° extension. Forty-one healthy older adults, 13 males and 28 females were included in the study. Mean (SD) age was 81.9 (4.89) years. Isometric muscle strength of the Quadriceps muscle was assessed with the Q Force at 110° of knee extension. Participants were measured at two sessions with a three to eight day interval between sessions. To determine relative reliability, the intraclass correlation coefficient (ICC) was calculated. To determine absolute reliability, Bland and Altman Limits of Agreement (LOA) were calculated and t-tests were performed. Relative reliability of the Q Force is good to excellent as all ICC coefficients are higher than 0.75. Generally a large 95 % LOA, reflecting only moderate absolute reliability, is found as exemplified for the peak torque left leg of -18.6 N to 33.8 N and the right leg of -9.2 N to 26.4 N was between 15.7 and 23.6 Newton representing 25.2 % to 39.9 % of the size of the mean. Small systematic differences in mean were found between measurement session 1 and 2. The present study shows that the Q Force has excellent relative test-retest reliability, but limited absolute test-retest reliability. Since the Q Force is relatively cheap and mobile it is suitable for

  8. The Relationship between Lean Mass and Contractile Properties of the Quadriceps in Elderly and Young Adults.

    PubMed

    Mau-Moeller, Anett; Bruhn, Sven; Bader, Rainer; Behrens, Martin

    2015-01-01

    Aging is associated with a loss of muscle mass (sarcopenia) and function. The twitch torque evoked by supramaximal electrical stimulation of peripheral nerves has been frequently used to analyse age-related modulations at the skeletal muscle level, such as changes in muscle mass. However, only one study has investigated the association between twitch contractile properties and skeletal muscle mass. A significant positive correlation between cross-sectional area and twitch parameters was found for the plantar flexors in young adults when using supramaximal doublet stimulation. It remains unclear whether this relationship exists for the quadriceps in elderly and young subjects when using single and doublet stimulation. The aim of the present study was to investigate the relationship between the lean mass of the thigh and evoked twitch properties of the quadriceps using single and doublet stimulation in two age groups. Fifteen young (aged 25.3 ± 3.6 years) and 15 elderly (aged 69.6 ± 3.1 years) subjects were recruited to participate in this study. The lean mass of the thigh was measured by dual-energy X-ray absorptiometry. Supramaximal single and doublet electrical stimulation was used to assess the contractile properties of the quadriceps. We observed no significant associations between lean mass and contractile properties when using single stimulation. Significant positive correlations were shown between lean mass and peak twitch torque evoked by doublet stimulation in young (r = 0.56; p = 0.030) and elderly (r = 0.54; p = 0.040) subjects. The analysis of twitch time and slope parameters demonstrated no significant correlations with lean mass. The peak twitch torque evoked by doublet electrical stimulation seems to be an appropriate measure to assess modulations in muscle mass in elderly and young subjects. The use of supramaximal single stimulation and the analysis of time and slope parameters may not be recommended for estimating changes in muscle mass

  9. Hamstrings to quadriceps peak torque ratios diverge between sexes with increasing isokinetic angular velocity.

    PubMed

    Hewett, Timothy E; Myer, Gregory D; Zazulak, Bohdanna T

    2008-09-01

    Our purpose was to determine if females demonstrate decreased hamstrings to quadriceps peak torque (H/Q) ratios compared to males and if H/Q ratios increase with increased isokinetic velocity in both sexes. Maturation disproportionately increases hamstrings peak torque at high velocity in males, but not females. Therefore, we hypothesised that mature females would demonstrate decreased H/Q ratios compared to males and the difference in H/Q ratio between sexes would increase as isokinetic velocity increased. Studies that analysed the H/Q ratio with gravity corrected isokinetic strength testing reported between 1967 and 2004 were included in our review and analysis. Keywords were hamstrings/quadriceps, isokinetics, peak torque and gravity corrected. Medline and Smart databases were searched combined with cross-checked bibliographic reference lists of the publications to determine studies to be included. Twenty-two studies were included with a total of 1568 subjects (1145 male, 423 female). Males demonstrated a significant correlation between H/Q ratio and isokinetic velocity (R=0.634, p<0.0001), and a significant difference in the isokinetic H/Q ratio at the lowest angular velocity (47.8+/-2.2% at 30 degrees /s) compared to the highest velocity (81.4+/-1.1% at 360 degrees /s, p<0.001). In contrast, females did not demonstrate a significant relationship between H/Q ratio and isokinetic velocity (R=0.065, p=0.77) or a change in relative hamstrings strength as the speed increased (49.5+/-8.8% at 30 degrees /s; 51.0+/-5.7% at 360 degrees /s, p=0.84). Gender differences in isokinetic H/Q ratios were not observed at slower angular velocities. However, at high knee flexion/extension angular velocities, approaching those that occur during sports activities, significant gender differences were observed in the H/Q ratio. Females, unlike males, do not increase hamstrings to quadriceps torque ratios at velocities that approach those of functional activities.

  10. A Comparison of Gluteus Maximus, Biceps Femoris, and Vastus Lateralis Electromyographic Activity in the Back Squat and Barbell Hip Thrust Exercises.

    PubMed

    Contreras, Bret; Vigotsky, Andrew D; Schoenfeld, Brad J; Beardsley, Chris; Cronin, John

    2015-12-01

    The back squat and barbell hip thrust are both popular exercises used to target the lower body musculature; however, these exercises have yet to be compared. Therefore, the purpose of this study was to compare the surface electromyographic (EMG) activity of the upper and lower gluteus maximus, biceps femoris, and vastus lateralis between the back squat and barbell hip thrust. Thirteen trained women (n = 13; age = 28.9 years; height = 164 cm; mass = 58.2 kg) performed estimated 10-repetition maximums (RM) in the back squat and barbell hip thrust. The barbell hip thrust elicited significantly greater mean (69.5% vs 29.4%) and peak (172% vs 84.9%) upper gluteus maximus, mean (86.8% vs 45.4%) and peak (216% vs 130%) lower gluteus maximus, and mean (40.8% vs 14.9%) and peak (86.9% vs 37.5%) biceps femoris EMG activity than the back squat. There were no significant differences in mean (99.5% vs 110%) or peak (216% vs 244%) vastus lateralis EMG activity. The barbell hip thrust activates the gluteus maximus and biceps femoris to a greater degree than the back squat when using estimated 10RM loads. Longitudinal training studies are needed to determine if this enhanced activation correlates with increased strength, hypertrophy, and performance.

  11. Changes in Quadriceps Muscle Thickness, Disease Severity, Nutritional Status, and C-Reactive Protein after Acute Stroke.

    PubMed

    Nozoe, Masafumi; Kanai, Masashi; Kubo, Hiroki; Kitamura, Yuka; Yamamoto, Miho; Furuichi, Asami; Takashima, Sachie; Mase, Kyoshi; Shimada, Shinichi

    2016-10-01

    Lower leg muscle wasting is common in stroke patients; however, patient characteristics in the acute phase are rarely studied. This study aimed to examine the relationship between changes in quadriceps muscle thickness and disease severity, nutritional status, and C-reactive protein (CRP) levels after acute stroke. Thirty-one consecutive patients with acute intracerebral hemorrhage or ischemic stroke had quadriceps muscle thickness measured in the paretic and nonparetic limbs within 1 week after admission (first week) and 2 weeks after the first examination (last week) using ultrasonography. We also determined the relationship between the percentage change in muscle thickness and disease severity, nutritional status, and CRP levels on admission. There was a significant correlation between changes in muscle thickness for both paretic and nonparetic sides and National Institutes of Health Stroke Scale (NIHSS) scores (paretic limb: r = -.46, P = .01; nonparetic limb: r = -.54, P = .002, respectively); however, there was no significant correlation with nutritional status on admission. Quadriceps muscle thickness was reduced more in the CRP-positive (≥.3 mg/dL) patients than in the CRP-negative (<.3 mg/dL) patients in the nonparetic limb (positive: -21.4 ± 12.1, negative: -11.4 ± 16.4%; P = .039), but not in the paretic limb (positive: -23.4 ± 9.0, negative: -19.1 ± 15.7; P = .27). A high NIHSS score and a positive CRP on admission were both significantly correlated with decreased quadriceps muscle thickness after acute stroke. Nutritional status on admission was not correlated with changes in quadriceps muscle thickness for these patients. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  12. Quadriceps Strength and Endurance After Posterior Cruciate Ligament Tears Versus Matched Group With Anterior Cruciate Ligament Tears.

    PubMed

    Lee, Dae-Hee; Han, Seung-Beom; Lee, Jin-Hyuck; Lee, Seok-Joo; Suh, Dong-Won; Jeong, Hye-Jin

    2015-06-01

    This study was designed to compare the preoperative strengths and endurances of the quadriceps and hamstring muscles in patients with anterior cruciate ligament (ACL) versus posterior cruciate ligament (PCL) tears. Quadriceps and hamstring muscle strength and endurance were compared between 20 prospectively enrolled patients with isolated PCL tears and a retrospective, matched control group of 20 patients with isolated ACL tears. The maximal torque (60°/s) and total work (180°/s) of the quadriceps and hamstring were evaluated with an isokinetic testing device. Total work (1,094.4 ± 505.8 J v 797.5 ± 332.7 J, P = .035) and peak torque (129.9 ± 56.2 N ∙ m v 98.2 ± 37.4 N ∙ m, P = .046) of the quadriceps muscle on the involved side were higher in the PCL tear group than in the ACL tear group. However, there were no significant differences between the PCL tear group and ACL tear group in hamstring muscle strength (45.8 ± 42.3 N ∙ m and 46.0 ± 24.4 N ∙ m, respectively; P = .940) and endurance (429.3 ± 238.9 J and 382.4 ± 256.1 J, respectively; P = .574) on the involved side. The strength and endurance of the quadriceps muscle of the injured limb were greater after PCL tears than after ACL tears. However, there were no significant between-group differences in hamstring muscle strength and endurance on the involved side. Level III, retrospective comparative study. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  13. Femoral quadriceps neuromuscular electrical stimulation after total knee arthroplasty: a systematic review

    PubMed Central

    Volpato, Helena Bruna Bettoni; Szego, Paulo; Lenza, Mario; Milan, Silvia Lefone; Talerman, Claudia; Ferretti, Mario

    2016-01-01

    ABSTRACT The purpose of this study was to evaluate the effects of neuromuscular electrical stimulation in patients submitted to total knee arthroplasty. This was a systematic review with no language or publication status restriction. Our search was made in Cochrane Library, MEDLINE, Embase and LILACS. Randomized or quasi-randomized clinical trials evaluating neuromuscular electrical stimulation after total knee arthroplasty were included. Four studies with moderate risk of bias and low statistical power were included, totalizing 376 participants. There was no statistically significant difference in knee function, pain and range of motion during 12 month follow-up. This review concluded that neuromuscular electrical stimulation was less effective than traditional rehabilitation in function, muscular strength and range of motion. However, this technique was useful for quadriceps activation during the first days after surgery. PMID:26537511

  14. Quadriceps fatigue caused by catchlike-inducing trains is not altered in old age.

    PubMed

    Allman, Brian L; Cheng, Arthur J; Rice, Charles L

    2004-12-01

    The relative loss of peak force from electrical stimulation protocols has provided inconsistent results when used to compare muscle fatigability between young and old adults. In addition to the effect of task on these comparisons, age-related alterations in the development and relaxation of force are possible factors that have not been considered. The purposes of this study were to compare the fatigability of the quadriceps of young (26.7 +/- 1.0 years) and old men (78.3 +/- 1.3 years), as assessed by changes in peak force, force time integral (FTI), and half-relaxation time (HRT), during intermittent electrical stimulation protocols, and to determine whether manipulation of the activation frequency affected the comparisons. Fatigue was caused by constant-frequency (CF), and catchlike-inducing (CI) train protocols, both of which consisted of intermittent trains (6 pulses on: 650 ms off) of stimulation. After each protocol, the force-generating capacity of the fatigued muscle was assessed with three trains of stimuli: a CF train, a CI train and a 1-s 50-HZ train. There was no effect of age on the loss of peak force or the development of low-frequency fatigue induced by either protocol. Conversely, irrespective of the protocol, the FTI was better maintained by approximately 9% in the old than young men. Because peak force did not differ between groups during fatigue, it is likely that the FTI was preserved by the exacerbated slowing of HRT in the quadriceps of the old men. The results confirm an apparent paradox between muscle fatigue and stimulation with CI trains: a single CI train produces greater force than a CF train in a fatigued muscle, but there is greater fatigue induced by repetitive CI than CF train stimulation. Old age did not affect this fatigue paradox.

  15. Motor adaptations to unilateral quadriceps fatigue during a bilateral pedaling task.

    PubMed

    Brøchner Nielsen, N-P; Hug, F; Guével, A; Fohanno, V; Lardy, J; Dorel, S

    2016-12-20

    This study was designed to investigate how motor coordination adapts to unilateral fatigue of the quadriceps during a constant-load bilateral pedaling task. We first hypothesized that this local fatigue would not be compensated within the fatigued muscles leading to a decreased knee extension power. Then, we aimed to determine whether this decrease would be compensated by between-joints compensations within the ipsilateral leg and/or an increased contribution of the contralateral leg. Fifteen healthy volunteers were tested during pedaling at 350 W before and after a fatigue protocol consisting of 15 minutes of electromyostimulation on the quadriceps muscle. Motor coordination was assessed from myoelectrical activity (22 muscles) and joint powers calculated through inverse dynamics. Maximal knee extension torque decreased by 28.3%±6.8% (P<.0005) immediately after electromyostimulation. A decreased knee extension power produced by the ipsilateral leg was observed during pedaling (-22.8±12.3 W, -17.0%±9.4%; P<.0005). To maintain the task goal, participants primarily increased the power produced by the non-fatigued contralateral leg during the flexion phase. This was achieved by an increase in hip flexion power confirmed by a higher activation of the tensor fascia latae. These results suggest no adjustment of neural drive to the fatigued muscles and demonstrate no concurrent ipsilateral compensation by the non-fatigued muscles involved in the extension pedaling phase. Although interindividual variability was observed, findings provide evidence that participants predominantly adapted by compensating with the contralateral leg during its flexion phase. Both neural (between legs) and mechanical (between pedals) couplings and the minimization of cost functions might explain these results.

  16. An Artificial Tendon to Connect the Quadriceps Muscle to the Tibia

    PubMed Central

    Melvin, Alan; Litsky, Alan; Mayerson, Joel; Stringer, Keith; Melvin, David; Juncosa-Melvin, Natalia

    2011-01-01

    No permanent, reliable artificial tendon exists clinically. Our group developed the OrthoCoupler™ device as a versatile connector, fixed at one end to a muscle, and adaptable at the other end to inert implants such as prosthetic bones or to bone anchors. The objective of this study was to evaluate four configurations of the device to replace the extensor mechanism of the knee in goats. Within muscle, the four groups had: (A) needle-drawn uncoated bundles, (B) needle-drawn coated bundles, (C) barbed uncoated bundles, and (D) barbed coated bundles. The quadriceps tendon, patella, and patellar tendon were removed from the right hind limb in 24 goats. The four groups (n=6 for each) were randomly assigned to connect the quadriceps muscle to the tibia (with a bone plate). Specimens were collected from each operated leg and contralateral unoperated controls both for mechanical testing and histology at 90 days post-surgery. In strength testing, maximum forces in the operated leg (vs. unoperated control) were 1288±123 N (vs. 1387±118 N) for group A, 1323±144 N (vs. 1396±779 N) for group B, 930±125 N (vs. 1337±126 N) for group C, and 968±109 N (vs. 1528±146 N) for group D (mean ± SEM). The strengths of the OrthoCoupler™ legs in the needled device groups were equivalent to unoperated controls (p=0.6), while both barbed device groups had maximum forces significantly lower than their controls (p=0.001). We believe this technology will yield improved procedures for clinical challenges in orthopaedic oncology, revision arthroplasty, tendon transfer, and tendon injury reconstruction. PMID:21520259

  17. Trunk muscle action compensates for reduced quadriceps force during walking after total knee arthroplasty.

    PubMed

    Li, Katherine; Ackland, David C; McClelland, Jodie A; Webster, Kate E; Feller, Julian A; de Steiger, Richard; Pandy, Marcus G

    2013-05-01

    Patients with total knee arthroplasty (TKA) frequently exhibit changes in gait biomechanics post-surgery, including decreased ranges of joint motion and changes in joint loading; however, the actions of the lower-limb muscles in generating joint moments and accelerating the center of mass (COM) during walking are yet to be described. The aim of the present study was to evaluate differences in lower-limb joint kinematics, muscle-generated joint moments, and muscle contributions to COM accelerations in TKA patients and healthy age-matched controls when both groups walk at the same speed. Each TKA patient was fitted with a posterior-stabilized total knee replacement and underwent patellar resurfacing. Three-dimensional gait analysis and subject-specific musculoskeletal modeling were used to determine lower-limb and trunk muscle forces and muscle contributions to COM accelerations during the stance phase of gait. The TKA patients exhibited a 'quadriceps avoidance' gait pattern, with the vasti contributing significantly less to the extension moment developed about the knee during early stance (p=0.036). There was a significant decrease in the contribution of the vasti to the vertical acceleration (support) (p=0.022) and forward deceleration of the COM (braking) (p=0.049) during early stance; however, the TKA patients compensated for this deficiency by leaning their trunks forward. This significantly increased the contribution of the contralateral back extensor muscle (erector spinae) to support (p=0.030), and that of the contralateral back rotators (internal and external obliques) to braking (p=0.004). These findings provide insight into the biomechanical causes of post-operative gait adaptations such as 'quadriceps avoidance' observed in TKA patients.

  18. Quadriceps muscle blood flow and oxygen availability during repetitive bouts of isometric exercise in simulated sailing.

    PubMed

    Vogiatzis, Ioannis; Andrianopoulos, Vasileios; Louvaris, Zafeiris; Cherouveim, Evgenia; Spetsioti, Stavroula; Vasilopoulou, Maroula; Athanasopoulos, Dimitrios

    2011-07-01

    In this study, we wished to determine whether the observed reduction in quadriceps muscle oxygen availability, reported during repetitive bouts of isometric exercise in simulated sailing efforts (i.e. hiking), is because of restricted muscle blood flow. Six national-squad Laser sailors initially performed three successive 3-min hiking bouts followed by three successive 3-min cycling tests sustained at constant intensities reproducing the cardiac output recorded during each of the three hiking bouts. The blood flow index (BFI) was determined from assessment of the vastus lateralis using near-infrared spectroscopy in association with the light-absorbing tracer indocyanine green dye, while cardiac output was determined from impedance cardiography. At equivalent cardiac outputs (ranging from 10.3±0.5 to 14.8±0.86 L · min(-1)), the increase from baseline in vastus lateralis BFI across the three hiking bouts (from 1.1±0.2 to 3.1±0.6 nM · s(-1)) was lower (P = 0.036) than that seen during the three cycling bouts (from 1.1±0.2 to 7.2±1.4 nM · s(-1)) (Cohen's d: 3.80 nM · s(-1)), whereas the increase from baseline in deoxygenated haemoglobin (by ∼17.0±2.9 μM) (an index of tissue oxygen extraction) was greater (P = 0.006) during hiking than cycling (by ∼5.3±2.7 μM) (Cohen's d: 4.17 μM). The results suggest that reduced vastus lateralis muscle oxygen availability during hiking arises from restricted muscle blood flow in the isometrically acting quadriceps muscles.

  19. Assessment of muscle architecture of the biceps femoris and vastus lateralis by ultrasound after a chronic stretching program.

    PubMed

    e Lima, Kelly M M; Carneiro, Simone P; Alves, Daniel de S; Peixinho, Carolina C; de Oliveira, Liliam F

    2015-01-01

    To evaluate the chronic effects of a static stretching program on the muscle architecture of biceps femoris (BF) and vastus lateralis (VL) muscles in ultrasound (US) images. Randomized controlled longitudinal trial. Biomechanics Laboratory of Physical Education School of the Army, Rio de Janeiro, Brazil. The study included 24 healthy and physically active male volunteers (19.05 ± 1.40 years, 1.73 ± 0.07 m, and 73.15 ± 8.33 kg), randomly allocated to 1 of 2 groups: stretching group (SG, n = 12) and control group (n = 12). The SG was submitted to 3 sets of 30 seconds of static stretching 3 times a week during 8 weeks. Ultrasound equipment (7.5 MHz) was used for the evaluation of BF and VL muscle architecture variables (pennation angle, fiber length, muscle thickness, and fascicle displacement) before and after training. Knee range of motion (ROM) and isometric flexion and extension torque (TQ) were also measured. There were no significant changes in muscle architecture, TQ, and maximum knee flexion angle (P > 0.05). However, maximum knee extension angle (MEA) increased significantly in the SG (pretraining: 159.37 ± 7.27 degrees and posttraining: 168.9 ± 3.7 degrees; P < 0.05). Volume or intensity (or both) of the stretching protocol was insufficient to cause structural changes in the VL and BF muscles. The increase in MEA could not be explained by muscle architecture changes. To describe changes in the VL and BF muscle tendon unit using US after a long-term stretching program to identify which structures are responsible for ROM increase.

  20. Surface Electromyography Assessments of the Vastus medialis and Rectus femoris Muscles and Creatine Kinase after Eccentric Contraction Following Glutamine Supplementation.

    PubMed

    Rahmani-Nia, Farhad; Farzaneh, Esmail; Damirchi, Arsalan; Majlan, Ali Shamsi; Tadibi, Vahid

    2014-03-01

    L-glutamine is the most abundant amino acid found in human muscle and plays an important role in protein synthesis and can reduce the levels of inflammation biomarkers and creatine kinase (CK) after training sessions. Delayed onset muscle soreness (DOMS) develops after intense exercise and is associated with an inflammatory response. The purpose of this study was to investigate the effect of glutamine supplementation on surface electromyography activity of the vastus medialis muscle (VMM) and rectus femoris muscle (RFM) and levels of creatine kinase after an eccentric contraction. SEVENTEEN HEALTHY MEN (AGE: 22.35±2.27yr; body mass: 69.91± 9.78kg; height: 177.08±4.32cm) were randomly assigned to experimental (n=9) and control groups (n=8) in a double-blind manner. In both groups, subjects were given L-glutamine supplementation (0.1g.kg(-1)) or placebo three times a week for 4 weeks. Median frequency (MDF) and mean power frequency (MPF) for VMM and RFM muscles and also CK measurements were performed before, 24h and 48 h after a resistance training session. The resistance training included 6 sets of eccentric leg extensions to exhaustion with 75% of 1RM. There was no significant difference between groups for MDF or MPF in VMM and RFM. The difference of CK level between the groups was also not significant. The results of this study indicate that glutamine supplementation has no positive effect on muscle injury markers after a resistance training session.

  1. What is the fate of the neck after a collum femoris preserving prosthesis? a nineteen years single center experience.

    PubMed

    Formica, Matteo; Cavagnaro, Luca; Basso, Marco; Zanirato, Andrea; Palermo, Augusto; Felli, Lamberto

    2017-07-01

    The aim of our study is to evaluate long-term outcomes from a cohort of patients treated with collum femoris preserving (CFP) stem correlating neck resorption with comorbidities, clinical outcomes, and complications. One hundred seventy-six patients (194 hips) were retrospectively reviewed with a minimum follow-up (f.u.) of ten years. Demographic and surgical data were collected. Clinical and radiological evaluation was performed at the last follow up. We calculated a neck resorption ratio (NRR) for each patient. Main complications were recorded. A p-value of <0.05 was considered significant. The mean Harris hip score (HHS) was 89.1 ± 5.7. The mean visual analogue scale (VAS) and Oxford hip score (OHS) values were 1.1 ± 1 and 41.3 ± 5.1, respectively. The mean leg length discrepancy was 1.5 mm ± 1.9. The mean NRR was 0.35. We observed six cases of aseptic loosening, two cases of infection, one implant revision for recurrent dislocation, and one stem revision after periprosthetic femoral fracture. The overall survival rate of the stem was 94.8%. Statistically significant associations were found between NRR and steroid therapy/stem malposition. Correlation between aseptic loosening and NRR was also statistically significant. Correlations between NRR and HHS/OHS were -0.34 and -0.28 respectively. Odds ratio for aseptic loosening were: 4.6 if NRR > 0.25; 16.9 if > 0.50 and 24.1 if > 0.75. CFP hip stem provided excellent long-term outcomes. NRR is correlated to steroid therapy and stem malposition. The risk of stem aseptic loosening rises according to NRR increase. Patients with an NRR > 0.5, especially if under steroid therapy or with stem malposition, should be strictly monitored.

  2. Graft maturity of the reconstructed anterior cruciate ligament 6 months postoperatively: a magnetic resonance imaging evaluation of quadriceps tendon with bone block and hamstring tendon autografts.

    PubMed

    Ma, Yong; Murawski, Christopher D; Rahnemai-Azar, Amir Ata; Maldjian, Catherine; Lynch, Andrew D; Fu, Freddie H

    2015-03-01

    The purpose of this study was to report the potential differences associated with graft maturity measured on magnetic resonance imaging (MRI) between quadriceps tendon with bone block and hamstring tendon autografts 6 months after ACL reconstruction. Twenty-six patients (15 male, 11 female; mean age 29.4 ± 17 years, range 13-46 years) who had undergone anatomic SB ACL reconstruction with either hamstring or quadriceps tendon with bone block autografts and had postoperative MRI 6 months after surgery. In 12 cases, the quadriceps tendon with bone block was used and hamstring in 14 cases. The signal/noise quotient was calculated to compare the difference between quadriceps tendon with bone block and hamstring autografts. Mean signal/noise quotient is lesser in quadriceps tendon with bone block (1.74 ± 0.39) compared with HS (2.44 ± 0.61) autografts (p = 0.020). For hamstring autograft, the distal region showed a significantly lower mean signal/noise quotient value compared with middle region, and the mean signal/noise quotient value in proximal region was the highest (distal vs middle p < 0.001; middle vs proximal p = 0.007; proximal vs distal p < 0.001). The mean signal/noise quotient of proximal region in quadriceps tendon with bone block autograft was lesser than that in hamstring. The middle region of the quadriceps tendon with bone block graft demonstrated the greatest signal/noise quotient [distal vs middle p = 0.001; middle vs proximal p = 0.027; proximal vs distal (n.s.)]. The maturity of quadriceps tendon with bone block was better in comparison with hamstring 6 months after anatomic SB ACL reconstruction. This study is clinically relevant in that modifying the individual rehabilitation according to the extent of graft maturity may be necessary to optimize patient function and prevent re-injury of the ACL graft.

  3. An EMG comparative analysis of quadriceps during isoinertial strength training using nonlinear scaled wavelets.

    PubMed

    Napoli, Nicholas J; Mixco, Anthony R; Bohorquez, Jorge E; Signorile, Joseph F

    2015-04-01

    High-speed resistance training is used to increase power; however, momentum can reduce the effectiveness of high-speed (HS) training when using weight-stack (WS) machines. This study used a non-linear scaled wavelet analysis to assess differences between pneumatic (P) and WS during seven HS or controlled speed (CS) repetitions. Vastus medialis (VM) and lateralis (VL), and rectus femoris (RF) EMG data were collected during leg extension exercises performed by five regular weight-trainers (mean age ± SD, 23.2 ± 2.9 years). Data were analyzed using continuous wavelet analysis to assess temporal Intensity distribution across eight frequency bands. Significant differences occurred due to speed for all muscles (p<.0001). P produced higher Intensity than WS for all muscles during HS (p<.0001), and VM and RF during CS (p<.001). The CON phase produced higher Intensity than ECC for the vasti muscles during CS (p<.0003), and VM and RF during HS (p<.0001). Intensity increased across repetitions plateauing earlier for the vasti than RF during CS. Regardless of the machine, Intensity levels peaked between the 25-53 Hz and 46-82 Hz (2nd and 3rd wavelets) bands. The results indicate that when the objective is increasing power through isoinertial training, P machines at HS appear to be the most effective alternative.

  4. Decision rules for egg recognition are related to functional roles and chemical cues in the queenless ant Dinoponera quadriceps

    NASA Astrophysics Data System (ADS)

    Tannure-Nascimento, Ivelize C.; Nascimento, Fabio S.; Dantas, José O.; Zucchi, Ronaldo

    2009-07-01

    The capacity to distinguish colony members from strangers is a key component in social life. In social insects, this extends to the brood and involves discrimination of queen eggs. Chemical substances communicate colony affiliation for both adults and brood; thus, in theory, all colony members should be able to recognize fellow nestmates. In this study, we investigate the ability of Dinoponera quadriceps workers to discriminate nestmate and non-nestmate eggs based on cuticular hydrocarbon composition. We analyzed whether cuticular hydrocarbons present on the eggs provide cues of discrimination. The results show that egg recognition in D. quadriceps is related to both age and the functional role of workers. Brood care workers were able to distinguish nestmate from non-nestmate eggs, while callow and forager workers were unable to do so.

  5. Treatment of Knee Arthrofibrosis and Quadriceps Insufficiency after Patellar Tendon Repair: A Case Report Including Use of the Graston Technique

    PubMed Central

    Black, Douglass W.

    2010-01-01

    Arthrofibrosis of the knee is a surgical complication that can limit range of motion, inhibit muscle activity, and decrease patient function. Optimal conservative treatment has not been well established in the literature, leaving a clinician with limited evidence for treatment planning. Described here is part of the rehabilitative course of care for a patient with arthrofibrotic limitations after a mid-substance patellar tendon repair with augmentation. Marked limitations in knee flexion range of motion and quadriceps activity were addressed using the Graston Technique to deal with soft-tissue adhesions; traditional physical therapy care was also provided. Clear improvement in range of motion and quadriceps activity and function was noted over the course of 5 treatments during 1 month. Treatment process and clinical reasoning are offered to promote understanding and to facilitate future inquiry. PMID:21589706

  6. Treatment of knee arthrofibrosis and quadriceps insufficiency after patellar tendon repair: a case report including use of the graston technique.

    PubMed

    Black, Douglass W

    2010-06-23

    Arthrofibrosis of the knee is a surgical complication that can limit range of motion, inhibit muscle activity, and decrease patient function. Optimal conservative treatment has not been well established in the literature, leaving a clinician with limited evidence for treatment planning. Described here is part of the rehabilitative course of care for a patient with arthrofibrotic limitations after a mid-substance patellar tendon repair with augmentation. Marked limitations in knee flexion range of motion and quadriceps activity were addressed using the Graston Technique to deal with soft-tissue adhesions; traditional physical therapy care was also provided. Clear improvement in range of motion and quadriceps activity and function was noted over the course of 5 treatments during 1 month. Treatment process and clinical reasoning are offered to promote understanding and to facilitate future inquiry.

  7. Surgical Treatment for Failure of Repair of Patellar and Quadriceps Tendon Rupture With Ipsilateral Hamstring Tendon Graft.

    PubMed

    Maffulli, Nicola; Papalia, Rocco; Torre, Guglielmo; Denaro, Vincenzo

    2017-03-01

    Tears of the patellar and quadriceps tendon are common in the active population, especially in athletes. At present, several techniques for surgical repair and reconstruction are available. When reruptures occur, a reconstruction is mandatory. In the present paper, we describe a surgical technique for patellar and quadriceps tendon reconstruction using ipsilateral hamstring autograft. After routine hamstring tendon harvesting, the tendon ends are prepared using a whip stitch. A transverse tunnel is drilled in the midportion of the patella, the hamstring graft is passed through the patella, and firmly secured to the patellar tunnel openings with sutures. The details of the technique are fully described. Autologous ipsilateral hamstring tendon grafts provide a secure sound means to manage these challenging injuries.

  8. Does Cruciate-Retaining Total Knee Arthroplasty Show Better Quadriceps Recovery than Posterior-Stabilized Total Knee Arthroplasty? - Objective Measurement with a Dynamometer in 102 Knees

    PubMed Central

    Cho, Kye-Youl; Song, Sang-Jun; Bae, Dae-Kyung

    2016-01-01

    Background Cruciate-retaining (CR) prostheses have been considered to produce more physiologic femoral rollback, provide better proprioception, and result in better quadriceps recovery than posterior-stabilized (PS) prostheses after total knee arthroplasty (TKA). However, there are very few studies demonstrating these benefits in an objective manner. We investigated whether CR-TKA could result in (1) better quadriceps recovery; (2) a greater proportion of patients with beyond the preoperative level of recovery; and (3) better clinical outcomes than PS-TKA. Methods This was a prospective non-randomized comparative study on the results of CR-TKA and PS-TKA. CR prostheses were used in 51 knees and PS prostheses in 51 knees. Quadriceps force was measured with a dynamometer preoperatively and at postoperative 6 weeks, 3 months, and 6 months consecutively. The Knee Society score (KSS) and range of motion (ROM) were also evaluated. Results There were no differences between two groups in terms of the objective quadriceps force during the follow-up period. The proportion of patients with beyond the preoperative level of recovery was similar between groups. Moreover, the KSS and ROM were not significantly different between two groups. Conclusions CR-TKA did not result in better quadriceps recovery than PS-TKA during the 6-month follow-up. In other words, PS-TKA could lead to comparable quadriceps recovery despite greater preoperative weaknesses such as more restricted ROM and more severe degenerative changes of the knee. PMID:27904719

  9. Effectiveness of injury prevention programs on developing quadriceps and hamstrings strength of young male professional soccer players.

    PubMed

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

    2013-12-18

    Muscular strength is an important factor which is crucial for performance and injury prevention in most sports. The purpose of this study was to evaluate the effects of the FIFA's Medical Assessment and Research Centre 11+ and HarmoKnee injury prevention programs on knee strength of young professional male soccer players. Thirty-six soccer players (age: 18.9 ± 1.4 years) were divided equally into three groups; the 11+, HarmoKnee and control groups. The programs were performed for 24 sessions. Hamstring and quadriceps strength was measured using the Biodex System 3 at 30°, 60° and 90° of knee flexion. The 11+ increased quadriceps strength in the dominant leg by 19.7% and 47.8% at 60°and 90° knee flexion, respectively, and in the non-dominant leg by 16%, 35.3% and 78.1 % at 30°, 60° and 90° knee flexion, respectively. The HarmoKnee group, however, showed increased quadriceps strength only at 90° i.e., by 85.7% in the dominant leg and 73.8% in the non-dominant leg. As for hamstring strength, only the 11+ group demonstrated an increment by 24.8% and 19.8% at 30° and 60° knee flexion in the dominant leg, and in the non-dominant leg, by 28.7% and 13.7% at 30° and 60° knee flexion, respectively. In conclusion, both warm-up programs improve quadriceps strength. The 11+ demonstrated improvement in hamstring strength while the HarmoKnee program did not indicate any improvement. We suggest adding eccentric hamstring components such as Nordic hamstring exercise to the HarmoKnee program in order to enhance hamstring strength.

  10. Effectiveness of Injury Prevention Programs on Developing Quadriceps and Hamstrings Strength of Young Male Professional Soccer Players

    PubMed Central

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

    2013-01-01

    Muscular strength is an important factor which is crucial for performance and injury prevention in most sports. The purpose of this study was to evaluate the effects of the FIFA’s Medical Assessment and Research Centre 11+ and HarmoKnee injury prevention programs on knee strength of young professional male soccer players. Thirty-six soccer players (age: 18.9 ± 1.4 years) were divided equally into three groups; the 11+, HarmoKnee and control groups. The programs were performed for 24 sessions. Hamstring and quadriceps strength was measured using the Biodex System 3 at 30°, 60° and 90° of knee flexion. The 11+ increased quadriceps strength in the dominant leg by 19.7% and 47.8% at 60°and 90° knee flexion, respectively, and in the non-dominant leg by 16%, 35.3% and 78.1 % at 30°, 60° and 90° knee flexion, respectively. The HarmoKnee group, however, showed increased quadriceps strength only at 90° i.e., by 85.7% in the dominant leg and 73.8% in the non-dominant leg. As for hamstring strength, only the 11+ group demonstrated an increment by 24.8% and 19.8% at 30° and 60° knee flexion in the dominant leg, and in the non-dominant leg, by 28.7% and 13.7% at 30° and 60° knee flexion, respectively. In conclusion, both warm-up programs improve quadriceps strength. The 11+ demonstrated improvement in hamstring strength while the HarmoKnee program did not indicate any improvement. We suggest adding eccentric hamstring components such as Nordic hamstring exercise to the HarmoKnee program in order to enhance hamstring strength. PMID:24511347

  11. The relationship between isokinetic quadriceps strength and laxity on gait analysis parameters in anterior cruciate ligament reconstructed knees.

    PubMed

    Gokeler, Alli; Schmalz, Thomas; Knopf, Elmar; Freiwald, Jürgen; Blumentritt, Siegmar

    2003-11-01

    Gait alterations after ACL reconstruction have been reported in the literature. The current study examined a group of 14 patients who all had an ACL reconstruction with a patellar tendon autograft. Kinetic and kinematic data were obtained from the knee during walking. The flexion-extension deficit (FED) calculated from the angular difference between maximal flexion and maximal extension during the stance phase in the ACL-reconstructed and the normal knee was measured. We investigated whether these alterations in gait are related to quadriceps strength and residual laxity of the knee. It may be that patients modify their gait patterns to protect the knee from excessive anterior translation of the tibia by reducing the amount of extension during stance. On the other hand, persistent quadriceps weakness may also cause changes in gait patterns as the quadriceps is functioning as an important dynamic stabilizer of the knee during stance. Results showed that patients had a significantly higher FED value (4.9+/-4.0) than a healthy control group in a previous study (1.3+/-0.9). This is caused mainly by an extension deficit during midstance. External extension moments of the knee (TZMAX were significantly lower in the current patients group than in a healthy control group (TZMAX -0.27+/-0.19 Nm/kg in patients vs. -0.08+/-0.06 Nm/kg in controls). There were no significant correlations between quadriceps strength and gait analysis parameters. Furthermore no correlation was found between the amount of laxity of the knee and gait. The relevance of this study lies in the fact that apparently the measured gait alterations cannot be explained solely by often used biomechanical indicators such as laxity and strength. The measured gait alterations may be a result of the surgical procedure with subsequent modified motor programming.

  12. Dynamics of corticospinal changes during and after high-intensity quadriceps exercise.

    PubMed

    Gruet, Mathieu; Temesi, John; Rupp, Thomas; Levy, Patrick; Verges, Samuel; Millet, Guillaume Y

    2014-08-01

    This study tested the hypothesis that during fatiguing quadriceps exercise, supraspinal fatigue develops late, is associated with both increased corticospinal excitability and inhibition and recovers quickly. Eight subjects performed 20 s contractions [15 s at 50% maximal voluntary contraction (MVC) followed by 5 s MVC] separated by a 10 s rest period until task failure. Transcranial magnetic stimulation (TMS) and electrical femoral nerve stimulation (PNS) were delivered ∼ 2 s apart during 50% MVC, during MVC and after MVC in relaxed muscle. Voluntary activation was assessed by TMS (VATMS) immediately before and after exercise and then three times over a 6 min recovery period. During exercise, MVC and twitch force evoked by PNS in relaxed muscle decreased progressively to 48 ± 8 and 36 ± 16% of control values, respectively (both P < 0.01). Significant changes in voluntary activation assessed by PNS and twitch evoked by TMS during MVC were observed during the last quarter of exercise only (from 96.4 ± 1.7 to 86 ± 13%, P = 0.03 and from 0.76 ± 0.8 to 4.9 ± 4.7% MVC, P = 0.02, from baseline to task failure, respectively). The TMS-induced silent period increased linearly during both MVC (by ∼ 79 ms) and 50% MVC (by ∼ 63 ms; both P < 0.01). Motor-evoked potential amplitude did not change during the protocol at any force levels. Both silent period and VATMS recovered within 2 min postexercise, whereas MVC and twitch force evoked by PNS in relaxed muscle recovered to only 84 ± 9 and 73 ± 17% of control values 6 min after exercise, respectively. In conclusion, high-intensity single-joint quadriceps exercise induces supraspinal fatigue near task failure, with increased intracortical inhibition and, in contrast to previous upper-limb results, unchanged corticospinal excitability. These changes recover rapidly after task failure, emphasizing the need to measure corticospinal adaptations immediately at task failure to avoid underestimation of exercise

  13. Relationship between functional hamstring: quadriceps ratios and running economy in highly trained and recreational female runners.

    PubMed

    Sundby, Oyvind H; Gorelick, Mark L S

    2014-08-01

    The purpose of this study was to investigate the relationship between running economy (RE), functional hamstring:quadriceps peak torque ratios (f-H:Q), and flexibility among female runners. Seven highly trained (HT) female runners (age: 25.7 ± 4.7 years, VO2peak of 62.0 ± 4.8 ml·kg-1·min-1) and 11 recreational female runners (age of 28.8 ± 5.6 years, VO2peak of 49.2 ± 4.6 ml·kg-1·min-1) were measured for maximal aerobic power (VO2peak), RE, heart rate, respiratory exchange ratio, f-H:Q (Hecc:Qcon and Hcon:Qecc), and sit-and-reach hamstring/trunk flexibility. On 2 separate days, RE was measured on a treadmill at 1% grade at 2 velocities (160.9 and 201.2 m·min-1) for 6 minutes each, and isokinetic knee strength was measured at 3 angular velocities (60, 120, and 180°·s-1) for both concentric and eccentric muscle actions. The unpaired t-tests showed a consistent trend toward higher f-H:Q ratios at all angular velocities among the HT runners. Highly trained runners had significantly higher Hecc:Qcon at 120°·s-1 (p ≤ 0.05) and 180°·s-1 (p ≤ 0.05). Whole group correlations demonstrated a significant correlation between Hcon:Qecc at 180°·s-1 and RE (ml·kg-1·km-1) at 201.2 m·min-1 (R = -0.48, p ≤ 0.05). No significant relationships were found between flexibility, or hamstring and quadriceps peak torque (N·m) and RE (p > 0.05). This cross-sectional analysis suggests that higher f-H:Q torque ratios, and not muscle strength per se, are associated with a lower metabolic cost of running. Therefore, runners should consider implementing hamstring exercises to improve their f-H:Q ratios.

  14. Anticonvulsant Effects of Fractions Isolated from Dinoponera quadriceps (Kempt) Ant Venom (Formicidae: Ponerinae)

    PubMed Central

    Nôga, Diana Aline Morais Ferreira; Brandão, Luiz Eduardo Mateus; Cagni, Fernanda Carvalho; Silva, Delano; de Azevedo, Dina Lilia Oliveira; Araújo, Arrilton; dos Santos, Wagner Ferreira; Miranda, Antonio; da Silva, Regina Helena; Ribeiro, Alessandra Mussi

    2016-01-01

    Natural products, sources of new pharmacological substances, have large chemical diversity and architectural complexity. In this context, some toxins obtained from invertebrate venoms have anticonvulsant effects. Epilepsy is a neurological disorder that affects about 65 million people worldwide, and approximately 30% of cases are resistant to pharmacological treatment. Previous studies from our group show that the denatured venom of the ant Dinoponera quadriceps (Kempt) protects mice against bicuculline (BIC)-induced seizures and death. The aim of this study was to investigate the anticonvulsant activity of compounds isolated from D. quadriceps venom against seizures induced by BIC in mice. Crude venom was fractionated by high-performance liquid chromatography (HPLC) resulting in six fractions referred to as DqTx1–DqTx6. A liquid chromatography-mass spectrometry (LC/MS) analysis revealed a major 431 Da compound in fractions DqTx1 and DqTx2. Fractions DqTx3 and DqTx4 showed a compound of 2451 Da and DqTx5 revealed a 2436 Da compound. Furthermore, the DqTx6 fraction exhibited a major component with a molecular weight of 13,196 Da. Each fraction (1 mg/mL) was microinjected into the lateral ventricle of mice, and the animals were observed in an open field. We did not observe behavioral alterations when the fractions were given alone. Conversely, when the fractions were microinjected 20 min prior to the administration of BIC (21.6 nM), DqTx1, DqTx4, and DqTx6 fractions increased the latency for onset of tonic-clonic seizures. Moreover, all fractions, except DqTx5, increased latency to death. The more relevant result was obtained with the DqTx6 fraction, which protected 62.5% of the animals against tonic-clonic seizures. Furthermore, this fraction protected 100% of the animals from seizure episodes followed by death. Taken together, these findings indicate that compounds from ant venom might be a potential source of new anticonvulsants molecules. PMID:28025529

  15. Anticonvulsant Effects of Fractions Isolated from Dinoponera quadriceps (Kempt) Ant Venom (Formicidae: Ponerinae).

    PubMed

    Nôga, Diana Aline Morais Ferreira; Brandão, Luiz Eduardo Mateus; Cagni, Fernanda Carvalho; Silva, Delano; de Azevedo, Dina Lilia Oliveira; Araújo, Arrilton; Dos Santos, Wagner Ferreira; Miranda, Antonio; da Silva, Regina Helena; Ribeiro, Alessandra Mussi

    2016-12-23

    Natural products, sources of new pharmacological substances, have large chemical diversity and architectural complexity. In this context, some toxins obtained from invertebrate venoms have anticonvulsant effects. Epilepsy is a neurological disorder that affects about 65 million people worldwide, and approximately 30% of cases are resistant to pharmacological treatment. Previous studies from our group show that the denatured venom of the ant Dinoponera quadriceps (Kempt) protects mice against bicuculline (BIC)-induced seizures and death. The aim of this study was to investigate the anticonvulsant activity of compounds isolated from D. quadriceps venom against seizures induced by BIC in mice. Crude venom was fractionated by high-performance liquid chromatography (HPLC) resulting in six fractions referred to as DqTx1-DqTx6. A liquid chromatography-mass spectrometry (LC/MS) analysis revealed a major 431 Da compound in fractions DqTx1 and DqTx2. Fractions DqTx3 and DqTx4 showed a compound of 2451 Da and DqTx5 revealed a 2436 Da compound. Furthermore, the DqTx6 fraction exhibited a major component with a molecular weight of 13,196 Da. Each fraction (1 mg/mL) was microinjected into the lateral ventricle of mice, and the animals were observed in an open field. We did not observe behavioral alterations when the fractions were given alone. Conversely, when the fractions were microinjected 20 min prior to the administration of BIC (21.6 nM), DqTx1, DqTx4, and DqTx6 fractions increased the latency for onset of tonic-clonic seizures. Moreover, all fractions, except DqTx5, increased latency to death. The more relevant result was obtained with the DqTx6 fraction, which protected 62.5% of the animals against tonic-clonic seizures. Furthermore, this fraction protected 100% of the animals from seizure episodes followed by death. Taken together, these findings indicate that compounds from ant venom might be a potential source of new anticonvulsants molecules.

  16. Anterior cruciate ligament reconstruction using quadriceps tendon autograft for adolescents with open physes- a technical note

    PubMed Central

    2011-01-01

    Background One major concern in the treatment of ACL lesions in children and adolescents with open physes is the risk of iatrogenic damage to the physes and a possibly resulting growth disturbance. Purpose The primary purpose of this article is to describe our technique of a transphyseal ACL reconstruction using quadriceps tendon-bone autograft in children and adolescents with open growth plates. The secondary aim is to report our early results in terms of postoperative growth disturbances which are considered to be a major concern in this challenging group of patients. It was our hypothesis that with our proposed technique no significant growth disturbances would occur. Methods From January 1997 to December 2007 49 consecutive children and adolescents with open growth plates were treated for a torn ACL using the aforementioned surgical technique. The patients (28 males and 21 females) with a median age at surgery of 13 (range 8-15) years were retrospectively evaluated. Outcome measures were follow-up radiographs (weight-bearing long leg radiographs of the injured and uninjured knee, anteroposterior and lateral views, a tangential view of the patella and a tunnel view of the injured knee) and follow-up notes (6 weeks, 3, 6, 12 months and until closing of physes) for occurrence of any tibial and/or femoral growth changes. Results: All of the 49 patients had a sufficient clinical and radiological follow-up (minimum 5 years, rate 100%). 48 cases did not show any clinical and radiological growth disturbance. One case of growth disturbance in a 10.5 years old girl was observed. She developed a progressive valgus-flexion deformity which was attributed to a malplacement of the autograft bone block within the femoral posterolateral epiphyseal plate leading to an early localized growth stop. None of the patients were reoperated due to ACL graft failure. Five of the patients underwent revision ACL surgery due to another adequate sports trauma after the growth-stop. The

  17. Postural response to vibration of triceps surae, but not quadriceps muscles, differs between people with and without knee osteoarthritis.

    PubMed

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

    2014-08-01

    Although proprioceptive impairments are reported in knee osteoarthritis (OA), there has been little investigation of the underlying causes. Muscle spindles make an important contribution to proprioception. This study investigated whether function of quadriceps, triceps surae, and tibialis anterior muscle spindles is altered in individuals with knee OA. Thirty individuals with knee OA (17 females, 66 ± 7 [mean ± SD] years) and 30 healthy asymptomatic controls (17 females, 65 ± 8 years) stood comfortably and blindfolded on a force plate. Mechanical vibration (60 Hz) was applied bilaterally over the quadriceps, triceps surae, or tibialis anterior muscles for th