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Sample records for single-leg knee extensor

  1. Knee extensors kinetic chain training in anterior cruciate ligament deficiency.

    Science.gov (United States)

    Perry, Mark C; Morrissey, Matthew C; Morrissey, Dylan; Knight, Philippa R; McAuliffe, Thomas B; King, John B

    2005-11-01

    Open kinetic chain (OKC) knee extensor resistance training has lost favour in rehabilitation of patients with knee ACLD due to concerns that this exercise is harmful to the remaining portion of the ACL and its secondary stabilizers, and will be less effective in improving function. In this randomized, single-blind clinical trial, closed and OKC knee extensor training were compared for their effects on knee laxity and function in patients with ACLD knees. Sixty-four patients with a diagnosis of knee ACLD (49 M, 15 F; mean age=30 years) were measured for knee laxity, using a ligament arthrometer, and function with the Hughston Clinic knee self-assessment questionnaire and maximal effort single leg jump testing. Between the above tests and identical tests carried out 6 weeks later, subjects trained using either open or closed kinetic chain resistance of their knee and hip extensors as part of formal physical therapy sessions three times per week for 6 weeks. The groups exhibited no statistically significant differences (pACL deficiency, and shows no superiority to CKC training.

  2. Knee proprioception and strength and landing kinematics during a single-leg stop-jump task.

    Science.gov (United States)

    Nagai, Takashi; Sell, Timothy C; House, Anthony J; Abt, John P; Lephart, Scott M

    2013-01-01

    The importance of the sensorimotor system in maintaining a stable knee joint has been recognized. As individual entities, knee-joint proprioception, landing kinematics, and knee muscles play important roles in functional joint stability. Preventing knee injuries during dynamic tasks requires accurate proprioceptive information and adequate muscular strength. Few investigators have evaluated the relationship between knee proprioception and strength and landing kinematics. To examine the relationship between knee proprioception and strength and landing kinematics. Cross-sectional study. University research laboratory. Fifty physically active men (age = 26.4 ± 5.8 years, height = 176.5 ± 8.0 cm, mass = 79.8 ± 16.6 kg). Three tests were performed. Knee conscious proprioception was evaluated via threshold to detect passive motion (TTDPM). Knee strength was evaluated with a dynamometer. A 3-dimensional biomechanical analysis of a single-legged stop-jump task was used to calculate initial contact (IC) knee-flexion angle and knee-flexion excursion. The TTDPM toward knee flexion and extension, peak knee flexion and extension torque, and IC knee-flexion angle and knee flexion excursion. Linear correlation and stepwise multiple linear regression analyses were used to evaluate the relationships of both proprioception and strength against landing kinematics. The α level was set a priori at .05. Enhanced TTDPM and greater knee strength were positively correlated with greater IC knee-flexion angle (r range = 0.281-0.479, P range = .001-.048). The regression analysis revealed that 27.4% of the variance in IC knee-flexion angle could be accounted for by knee-flexion peak torque and TTDPM toward flexion (P = .001). The current research highlighted the relationship between knee proprioception and strength and landing kinematics. Individuals with enhanced proprioception and muscular strength had better control of IC knee-flexion angle during a dynamic task.

  3. Influence of increasing knee flexion angle on knee-ankle varus stress during single-leg jump landing

    Directory of Open Access Journals (Sweden)

    Mariam A. Ameer, PhD

    2017-12-01

    Full Text Available Objectives: The primary aim of this study was to identify the relationship between the peak knee flexion angle and knee-ankle varus stress in the landing phase of the single-leg jump during running. Methods: Fifteen male handball players from the first Saudi Arabian handball team were incorporated in this study. Each player performed a single-leg jump-land after running a fixed distance of 450 cm. The data were measured using a 3D motion analysis system. The maximum knee flexion angle, knee varus angle, centre of pressure pathway in the medio-lateral direction, and ankle varus moment were measured. Results: The Pearson Product Moment Correlation showed that a greater knee flexion angle was related to a greater lateral displacement of the centre of pressure (r = 0.794, P = 0.000, a greater ankle varus moment (r = 0.707, P = 0.003, and a greater knee varus angle (r = 0.753, P = 0.001. In addition, the greater ankle varus moment was related to the greater lateral displacement of the centre of pressure (r = 0.734, P = 0.002. Conclusions: These findings may help physical therapists and conditioning professionals to understand the impact of increasing knee flexion angle on the lower limb joints. Such findings may help to develop training protocols for enhancing the lateral body reaction during the landing phase of the single-leg jump, which may protect the knee and ankle joints from excessive varus stresses. Keywords: 3D motion analysis, Ankle kinetic, Centre of pressure pathway, Handball playing, Knee kinematic, Single-leg jump

  4. The Relationship of Anticipatory Gluteus Medius Activity to Pelvic and Knee Stability in the Transition to Single-Leg Stance.

    Science.gov (United States)

    Kim, Daehan; Unger, Janelle; Lanovaz, Joel L; Oates, Alison R

    2016-02-01

    The knee abduction moment in a weight-bearing limb is an important risk factor of conditions such as patellofemoral pain and knee osteoarthritis. Excessive pelvic drop in single-leg stance can increase the knee abduction moment. The gluteus medius muscle is crucial to prevent pelvic drop and must be activated in anticipation of the transition from double-leg to single-leg stance. To examine the relationship of anticipatory activity of the gluteus medius to pelvic drop and knee abduction moment. Observational, cross-sectional correlational study. Research laboratory. Twenty female adults (mean age 22.6 years, standard deviation 2.5) were recruited and fully participated. Participant selection was limited to healthy women who did not have a history of knee and ankle ligament injuries, any indication of knee, hip, and/or low back pain, and/or knowledge of the proper squat technique. Participants performed 16 single-leg mini squats on their nondominant leg. The onset and magnitude of anticipatory gluteus medius activity were measured in relation to toe-off of the dominant leg during the transition from double-leg to single-leg stance. Preplanned correlations between anticipatory gluteus medius onset and its activation magnitude, pelvic obliquity, and knee abduction moment were examined. The magnitude of anticipatory gluteus medius activity was significantly correlated with the knee abduction moment (rs (18) = -0.303, P pelvic obliquity (rs (18) = 0.361, P pelvic obliquity. The amount of gluteus medius activity is more important for controlling knee and pelvic stability in the frontal plane than the onset of activation. Copyright © 2016 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  5. Greater Hip Extension but Not Hip Abduction Explosive Strength Is Associated With Lesser Hip Adduction and Knee Valgus Motion During a Single-Leg Jump-Cut.

    Science.gov (United States)

    Cronin, Baker; Johnson, Samuel T; Chang, Eunwook; Pollard, Christine D; Norcross, Marc F

    2016-04-01

    The relationships between hip abductor and extensor strength and frontal plane hip and knee motions that are associated with anterior cruciate ligament injury risk are equivocal. However, previous research on these relationships has evaluated relatively low-level movement tasks and peak torque rather than a time-critical strength measure such as the rate of torque development (RTD). Females with greater hip abduction and extension RTD would exhibit lesser frontal plane hip and knee motion during a single-leg jump-cutting task. Descriptive laboratory study. Forty recreationally active females performed maximal isometric contractions and single-leg jump-cuts. From recorded torque data, hip extension and abduction RTD was calculated from torque onset to 200 ms after onset. Three-dimensional motion analysis was used to quantify frontal plane hip and knee kinematics during the movement task. For each RTD measure, jump-cut biomechanics were compared between participants in the highest (high) and lowest (low) RTD tertiles. No differences in frontal plane hip and knee kinematics were identified between high and low hip abduction RTD groups. However, those in the high hip extension RTD group exhibited lower hip adduction (high, 3.8° ± 3.0°; low, 6.5° ± 3.0°; P = .019) and knee valgus (high, -2.5° ± 2.3°; low, -4.4° ± 3.2°; P = .046) displacements during the jump-cut. In movements such as cutting that are performed with the hip in a relatively abducted and flexed position, the ability of the gluteus medius to control hip adduction may be compromised. However, the gluteus maximus, functioning as a hip abductor, may take on a pivotal role in controlling hip adduction and knee valgus motion during these types of tasks. Training with a specific emphasis on increasing explosive strength of the hip extensors may be a means through which to improve frontal plane hip and knee control during high-risk maneuvers such as cutting.

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

    Science.gov (United States)

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

    2017-11-01

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

  7. Effects of foot rotation positions on knee valgus during single-leg drop landing: Implications for ACL injury risk reduction.

    Science.gov (United States)

    Teng, P S P; Kong, P W; Leong, K F

    2017-06-01

    Non-contact anterior cruciate ligament (ACL) injuries commonly occur when athletes land in high risk positions such as knee valgus. The position of the foot at landing may influence the transmission of forces from the ankle to the knee. Using an experimental approach to manipulate foot rotation positions, this study aimed to provide new insights on how knee valgus during single-leg landing may be influenced by foot positions. Eleven male recreational basketball players performed single-leg drop landings from a 30-cm high platform in three foot rotation positions (toe-in, toe-forward and toe-out) at initial contact. A motion capture system and a force plate were used to measure lower extremity kinematics and kinetics. Knee valgus angles at initial contact (KVA) and maximum knee valgus moments (KVM), which were known risk factors associated with ACL injury, were measured. A one-way repeated measures Analysis of Variance was conducted (α=0.05) to compare among the three foot positions. Foot rotation positions were found to have a significant effect on KVA (p<0.001, η 2 =0.66) but the difference between conditions (about 1°) was small and not clinically meaningful. There was a significant effect of foot position on KVM (p<0.001, η 2 =0.55), with increased moment observed in the toe-out position as compared to toe-forward (p=0.012) or toe-in positions (p=0.002). When landing with one leg, athletes should avoid extreme toe-out foot rotation positions to minimise undesirable knee valgus loading associated with non-contact ACL injury risks. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Intrinsic properties of the knee extensor muscles after subacute stroke

    NARCIS (Netherlands)

    Horstman, A.M.H.; Gerrits, K.H.L.; Beltman, M.J.; Koppe, P.A.; Janssen, T.W.J.; de Haan, A.

    2010-01-01

    Horstman AM, Gerrits KH, Beltman MJ, Koppe PA, Janssen, TW, de Haan A. Intrinsic properties of the knee extensor muscles after subacute stroke. Objective: To characterize muscle properties of paretic lower-limb (PL) and nonparetic lower-limb (NL) knee extensors in patients with subacute stroke.

  9. Frontal and transverse plane hip kinematics and gluteus maximus recruitment correlate with frontal plane knee kinematics during single-leg squat tests in women.

    Science.gov (United States)

    Hollman, John H; Galardi, Christy M; Lin, I-Hsuan; Voth, Brandon C; Whitmarsh, Crystal L

    2014-04-01

    Hip muscle dysfunction may be associated with knee valgus that contributes to problems like patellofemoral pain syndrome. The purpose of this study was to (1) compare knee and hip kinematics and hip muscle strength and recruitment between "good" and "poor" performers on a single-leg squat test developed to assess hip muscle dysfunction and (2) examine relationships between hip muscle strength, recruitment and frontal plane knee kinematics to see which variables correlated with knee valgus during the test. Forty-one active women classified via visual rating as "good" or "poor" performers on the test participated. Participants completed 5-repetition single-leg squat tests. Isometric hip extension and abduction strength, gluteus maximus and gluteus medius recruitment, and 3-dimensional hip and knee kinematics during the test were compared between groups and examined for their association with frontal plane knee motion. "Poor" performers completed the test with more hip adduction (mean difference=7.6°) and flexion (mean difference=6.3°) than "good" performers. No differences in knee kinematics, hip strength or hip muscle recruitment occurred. However, the secondary findings indicated that increased medial hip rotation (partial r=0.94) and adduction (partial r=0.42) and decreased gluteus maximus recruitment (partial r=0.35) correlated with increased knee valgus. Whereas hip muscle function and knee kinematics did not differ between groups as we'd hypothesized, frontal plane knee motion correlated with transverse and frontal plane hip motions and with gluteus maximus recruitment. Gluteus maximus recruitment may modulate frontal plane knee kinematics during single-leg squats. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Effect of Feedback Corrective Exercise on Knee Valgus and Electromyographic Activity of Lower Limb Muscles in Single Leg Squat

    Directory of Open Access Journals (Sweden)

    Negar Koorosh-fard

    2015-07-01

    Full Text Available Objective: The aim of this study was assessing the effect of feedback correcting exercise in front of mirror during running on frontal plane knee and pelvic kinematic and electromyography activity of some lower extremity muscles in single leg squat (SLS. Materials & Methods: This study was quasi experimental. 23 active female subjects participated in two experimental and control groups with mean age (21.86± 2.43 years .experimental group contains subjects with knee valgus and pelvic drop angle more than a mean plus one standard deviation of the population in functional SLS. Muscular activity (RMS of gluteus maximus, Gluteus medius, rectus femoris, vastus medialis, vastus lateralis, biceps femoris and semitendinosus, angle of knee valgus and pelvic drop were register in end of SLS Pre and post of 8 training sessions. Comparing Variable has done with independent t statistical test between 2 groups and pair sample t test within each groups with significant level of 0.05. Results: Statistical analysis Before training showed no significant differences in pelvic drop between two groups (P&ge0.05, but knee valgus angle was significantly more than control group (P&le0.05. In spit that most muscle activities (% MVC except biceps femoris (P&le0.05, were greater in experimental group, no significant difference (P&ge0.05 has seen in two groups. Comparing pre and post test has showed no significant difference in knee valgus of experimental group, however it decreased around 2 degrees and although %MVC decreased in all muscles, just rectuse femoris has shown significant difference (P&le0.05. No significant difference has seen in control group in all variables (P&ge0.05. Conclusion: Findings showed poor neuromuscular control in experimental group which improved to some extent after training because lower muscle activity and energy consumption in specific movement with similar kinematic indicate improvement of motor control or cause learning. It seems that

  11. Can two-dimensional video analysis during single-leg drop vertical jumps help identify non-contact knee injury risk? A one-year prospective study.

    Science.gov (United States)

    Dingenen, Bart; Malfait, Bart; Nijs, Stefaan; Peers, Koen H E; Vereecken, Styn; Verschueren, Sabine M P; Staes, Filip F

    2015-10-01

    Previous studies showed that the amount of hip flexion and the combination of knee valgus and lateral trunk motion, measured with two-dimensional video analysis, were related to three-dimensional measured knee joint moments during single-leg drop vertical jumps, but it remains unclear whether these measurements can be used to identify non-contact knee injury risk. Fifty injury-free female athletes participated in the study. Two-dimensional video analysis was used to measure hip flexion, knee valgus and lateral trunk motion angles during single-leg drop vertical jumps. Time loss non-contact knee injuries were registered during a one-year follow-up. Independent t-tests and receiver operating characteristic analysis were used to analyze the predictive ability of the two-dimensional angles. Seven participants sustained a time loss non-contact knee injury. Hip flexion was not significantly different between groups (P>.05). The combination of knee valgus and lateral trunk motion was significantly smaller in the injured (P=.036) and non-injured legs (P=.009) of the future injured group compared with the respective matched leg of the non-injured group. The receiver operating characteristic analysis showed a significant discriminative accuracy between groups for the combination of knee valgus and lateral trunk motion of the uninjured leg of the future injured group with the matched leg of the non-injured group (area under curve=0.803; P=.012). The measurement of a combination of increased knee valgus and ipsilateral trunk motion during the single-leg drop vertical jump with two-dimensional video analysis can be used to help identify female athletes with increased non-contact knee injury risk. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Functional instability of the ankle: differences in patterns of ankle and knee movement prior to and post landing in a single leg jump.

    Science.gov (United States)

    Caulfield, B M; Garrett, M

    2002-01-01

    The aim of this study was to investigate motor control in subjects with functional instability of the ankle joint. This was achieved by analysing patterns of lower extremity motion prior to and immediately following landing during single leg jumping in subjects with functional instability of the ankle. Fourteen subjects with unilateral functional instability and 10 healthy control subjects performed single leg jumps from a 40 cm height whilst angular displacement of their ankle and knee joints were recorded. Subjects with functional instability demonstrated significantly greater ankle dorsiflexion over the period encompassing 10 ms pre landing to 20 ms post landing (p < 0.05). They also exhibited a significantly greater level of knee flexion than controls over the period from 20 ms pre landing to 60 ms post landing (p < 0.05). The timing of these significant differences leads us to conclude that they do not arise as a result of reflexively mediated peripheral events following landing.

  13. Abdominal Hollowing Reduces Lateral Trunk Displacement During Single-Leg Squats in Healthy Females But Does Not Affect Peak Hip Abduction Angle or Knee Abductio Angle/Moment.

    Science.gov (United States)

    Linde, Lukas D; Archibald, Jessica; Lampert, Eve C; Srbely, John Z

    2017-07-17

    Females suffer 4-6 times more non-contact anterior cruciate ligament (ACL) injuries than males due to neuromuscular control deficits of the hip musculature leading to increases in hip adduction angle, knee abduction angle, and knee abduction moment during dynamic tasks such as single-leg squats. Lateral trunk displacement has been further related to ACL injury risk in females, leading to the incorporation of core strength/stability exercises in ACL preventative training programs. However, the direct mechanism relating lateral trunk displacement and lower limb ACL risk factors is not well established. To assess the relationship between lateral trunk displacement and lower limb measures of ACL injury risk by altering trunk control through abdominal activation techniques during single-leg squats in healthy females. Interventional Study Setting: Movement and Posture Laboratory Participants: 13 healthy females (21.3±0.88y, 1.68±0.07m, 58.27±5.46kg) Intervention: Trunk position and lower limb kinematics were recorded using an optoelectric motion capture system during single-leg squats under differing conditions of abdominal muscle activation (abdominal hollowing, abdominal bracing, control), confirmed via surface electromyography. Lateral trunk displacement, peak hip adduction angle, peak knee abduction angle/moment, and average muscle activity from bilateral internal oblique, external oblique, and erector spinae muscles. No differences were observed for peak lateral trunk displacement, peak hip adduction angle or peak knee abduction angle/moment. Abdominal hollowing and bracing elicited greater muscle activation than the control condition, and bracing was greater than hollowing in four of six muscles recorded. The lack of reduction in trunk, hip, and knee measures of ACL injury risk during abdominal hollowing and bracing suggests that these techniques alone may provide minimal benefit in ACL injury prevention training.

  14. Dynamic knee valgus alignment influences impact attenuation in the lower extremity during the deceleration phase of a single-leg landing.

    Directory of Open Access Journals (Sweden)

    Akihiro Tamura

    Full Text Available Dynamic knee valgus during landings is associated with an increased risk of non-contact anterior cruciate ligament (ACL injury. In addition, the impact on the body during landings must be attenuated in the lower extremity joints. The purpose of this study was to investigate landing biomechanics during landing with dynamic knee valgus by measuring the vertical ground reaction force (vGRF and angular impulses in the lower extremity during a single-leg landing. The study included 34 female college students, who performed the single-leg drop vertical jump. Lower extremity kinetic and kinematic data were obtained from a 3D motion analysis system. Participants were divided into valgus (N = 19 and varus (N = 15 groups according to the knee angular displacement during landings. The vGRF and angular impulses of the hip, knee, and ankle were calculated by integrating the vGRF-time curve and each joint's moment-time curve. vGRF impulses did not differ between two groups. Hip angular impulse in the valgus group was significantly smaller than that in the varus group (0.019 ± 0.033 vs. 0.067 ± 0.029 Nms/kgm, p<0.01, whereas knee angular impulse was significantly greater (0.093 ± 0.032 vs. 0.045 ± 0.040 Nms/kgm, p<0.01. There was no difference in ankle angular impulse between the groups. Our results indicate that dynamic knee valgus increases the impact the knee joint needs to attenuate during landing; conversely, the knee varus participants were able to absorb more of the landing impact with the hip joint.

  15. Lower limb muscle pre-motor time measures during a choice reaction task associate with knee abduction loads during dynamic single leg landings.

    Science.gov (United States)

    McLean, Scott G; Borotikar, Bhushan; Lucey, Sarah M

    2010-07-01

    Female neuromuscular control during dynamic landings is considered central to their increased ACL injury risk relative to males. There is limited insight, however, into the neuromuscular parameters governing this risk, which may hinder prevention success. This study targeted a new screenable and potentially trainable neuromuscular risk factor. Specifically, we examined whether lower limb muscle pre-motor times, being the time between stimulus presentation and initiation of the muscle EMG burst, elicited during a simple choice reaction task correlated with knee abduction loads during separate single leg landings. Twenty female NCAA athletes had muscle (n=8) pre-motor time and knee biomechanics data recorded bilaterally during a choice reaction task. Knee biomechanics were also quantified during anticipated and unanticipated single (dominant and non-dominant) leg landings. Mean peak knee abduction loads during landings were submitted to a two-way ANOVA to test for limb and decision effects. Individual regression coefficients were initially computed between-limb-based muscle pre-motor times and peak abduction moments elicited during both the choice reaction and landing tasks. Limb-based linear stepwise regression coefficients were also computed between muscle PMT's demonstrating significant (Pmuscle pre-motor times during a specific choice reaction task are associated with peak knee abduction loads during separate single leg landings. These muscles appear critical in stabilizing the knee against the extreme dynamic load states associated with such tasks. Targeted screening and training of supraspinal processes governing these muscle pre-motor times may ultimately enable external knee loads associated with landings to be more effectively countered by the overarching neuromuscular strategy. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  16. Knee extensor strength and risk of structural, symptomatic and functional decline in knee osteoarthritis

    DEFF Research Database (Denmark)

    Culvenor, Adam G; Ruhdorfer, Anja; Juhl, Carsten

    2017-01-01

    -analysis revealed that lower knee extensor strength was associated with an increased risk of symptomatic (WOMAC-Pain: odds ratio [OR] 1.35, 95% confidence interval [CI] 1.10, 1.67) and functional decline (WOMAC-Function: OR 1.38, 95%CI 1.00, 1.89; chair-stand task: OR 1.03, 95%CI 1.03, 1.04), but not increased risk......OBJECTIVE: To perform a systematic review and meta-analysis on the association between knee extensor strength and the risk of structural, symptomatic, or functional deterioration in individuals with or at risk of knee osteoarthritis (KOA). METHODS: We systematically identified and methodologically...... appraised all longitudinal studies (≥1-year follow-up) reporting an association between knee extensor strength and structural (tibiofemoral, patellofemoral), symptomatic (self-reported, knee replacement), or functional (subjective, objective) decline in individuals with or at risk of radiographic...

  17. Imaging of postoperative knee extensor mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Motamedi, Kambiz [David Geffen School of Medicine at UCLA, Musculoskeletal Imaging-Department of Radiology, 200 Medical Plaza, Suite 165-59, Los Angeles, CA 90095 (United States); Seeger, Leanne L. [David Geffen School of Medicine at UCLA, Musculoskeletal Imaging-Department of Radiology, 200 Medical Plaza, Suite 165-57, Los Angeles, CA 90095 (United States); Hame, Sharon L. [David Geffen School of Medicine at UCLA, Department of Orthopedic Surgery, Box 956902, 76-143 CHS, Los Angeles, CA 90095 (United States)

    2005-05-01

    Disorders of the anterior knee are common and include patellofemoral syndrome, patella instability, patella fracture, and patellar and quadriceps tendon ruptures. Depending on the operative procedure performed, the post-operative imaging appearance of these knees may be confusing. It is crucial for the radiologist to be familiar with the procedures performed in order to recognize the postoperative findings. Radiologists must be able to interpret hardware (anchors, screw and wires) and disruptions in soft tissue planes that may persist with these types of procedures.

  18. Relation between peak knee flexion angle and knee ankle kinetics in single-leg jump landing from running: a pilot study on male handball players to prevent ACL injury.

    Science.gov (United States)

    Ameer, Mariam A; Muaidi, Qassim I

    2017-09-01

    The relationship between knee kinematics and knee-ankle kinetics during the landing phase of single leg jumping has been widely studied to identify proper strategies for preventing non-contact ACL injury. However, there is a lack of study on knee-ankle kinetics at peak knee flexion angle during jumping from running. Hence, the purpose of this study is to establish the relationship between peak knee flexion angle, knee extension moment, ankle plantar flexion moment and ground reaction force in handball players in order to protect ACL from excessive stress during single leg jumping. In addition, the study also clarifies the role of calf muscles in relieving part of ACL stresses with different knee flexion angles during landing. Fifteen active male elite handball players of Saudi Arabia have participated in this study (Age = 22.6 ± 3.5years, Height = 182 ± 3.7 cm, Weight = 87.5 ± 10.2 kg). The players performed three successful landings of single-leg jump following running a fixed distance of about 450cm. The data were collected using a 3D motion capture and analysis system (VICON). Pearson product moment correlation coefficients showed that greater peak knee flexion angle is related significantly to both lesser knee extension moment (r = -.623, P = .013) and vertical component of ground reaction force (VGRF) (r = -.688, P = .005) in landing phase. Moreover, increasing the peak knee flexion angle in landing phase tends to increase the ankle plantar flexion moment significantly (r = .832, P = .000). With an increase of the peak knee flexion angle during single leg jump landing from running, there would be less knee extension moment, low impact force and more plantar flexion moment. As such, the clinical implication of this study is that there may be a possible protective mechanism by increasing the knee flexion angle during landing phase, which tends to protect the ACL from vigorous strain and injuries.

  19. Knee extensor mechanism allograft reconstruction following chronic disruption.

    Science.gov (United States)

    Murgier, J; Boisrenoult, P; Pujol, N; Beranger, J S; Tardy, N; Steltzlen, C; Beaufils, P

    2015-11-01

    The management of chronic extensor mechanism disruption can be complex. One of the options is allograft reconstruction. The goal of this study was to present the surgical procedure and provide preliminary results with this technique. The allograft uses the whole extensor mechanism (anterior tibial tubercle, patellar ligament, patella, quadriceps tendon). The native patella can be completely removed if the quality of the bone is poor, otherwise a bone groovecan be created to receive the allograft. The allograft is tightly tensioned with the knee in full extension. This surgical technique was performed 5 times with a minimum follow-up of 1 year. Active extension was recovered in all cases. The mean postoperative KOOS was 55.5 the IKS function score was 68.5 and the IKS knee score was 83. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  20. Greater Hip Extension but Not Hip Abduction Explosive Strength Is Associated With Lesser Hip Adduction and Knee Valgus Motion During a Single-Leg Jump-Cut

    OpenAIRE

    Cronin, Baker; Johnson, Samuel T.; Chang, Eunwook; Pollard, Christine D.; Norcross, Marc F.

    2016-01-01

    Background: The relationships between hip abductor and extensor strength and frontal plane hip and knee motions that are associated with anterior cruciate ligament injury risk are equivocal. However, previous research on these relationships has evaluated relatively low-level movement tasks and peak torque rather than a time-critical strength measure such as the rate of torque development (RTD). Hypothesis: Females with greater hip abduction and extension RTD would exhibit lesser frontal plane...

  1. The effect of knee extensor open kinetic chain resistance training in the ACL-injured knee.

    Science.gov (United States)

    Barcellona, Massimo G; Morrissey, Matthew C; Milligan, Peter; Clinton, Melissa; Amis, Andrew A

    2015-11-01

    To investigate the effect of different loads of knee extensor open kinetic chain resistance training on anterior knee laxity and function in the ACL-injured (ACLI) knee. Fifty-eight ACLI subjects were randomised to one of three (12-week duration) training groups. The STAND group trained according to a standardised rehabilitation protocol. Subjects in the LOW and HIGH group trained as did the STAND group but with the addition of seated knee extensor open kinetic chain resistance training at loads of 2 sets of 20 repetition maximum (RM) and 20 sets of 2RM, respectively. Anterior knee laxity and measurements of physical and subjective function were performed at baseline, 6 and 12 weeks. Thirty-six subjects were tested at both baseline and 12 weeks (STAND n = 13, LOW n = 11, HIGH n = 12). The LOW group demonstrated a reduction in 133 N anterior knee laxity between baseline and 12 weeks testing when compared to the HIGH and the STAND groups (p = 0.009). Specifically, the trained-untrained knee laxity decreased an average of approximately 5 mm in the LOW group while remaining the same in the other two groups. Twelve weeks of knee extensor open kinetic chain resistance training at loads of 2 sets of 20RM led to a reduction in anterior knee laxity in the ACLI knee. This reduction in laxity does not appear to offer any significant short-term functional advantages when compared to a standard rehabilitation protocol. These results indicate that knee laxity can be decreased with resistance training of the thigh muscles. Randomised controlled trial, Level II.

  2. Isometric muscle function of knee extensors and the relation with functional performance in patients with stroke

    NARCIS (Netherlands)

    Gerrits, K.H.L.; Beltman, M.J.; Koppe, P.A.; Konijnenbelt, H.; Elich, P.D.; de Haan, A.; Janssen, T.W.J.

    2009-01-01

    Gerrits KH, Beltman MJ, Koppe PA, Konijnenbelt H, Elich PD, de Haan A, Janssen TW. Isometric muscle function of knee extensors and the relation with functional performance in patients with stroke. Objective: (1) To examine the isometric strength, speed, and fatigue resistance of the knee extensors

  3. Reliability of contractile properties of the knee extensor muscles in individuals with post-polio syndrome

    NARCIS (Netherlands)

    Voorn, Eric L.; Brehm, Merel A.; Beelen, Anita; de Haan, Arnold; Nollet, Frans; Gerrits, Karin H. L.

    2014-01-01

    To assess the reliability of contractile properties of the knee extensor muscles in 23 individuals with post-polio syndrome (PPS) and 18 age-matched healthy individuals. Contractile properties of the knee extensors were assessed from repeated electrically evoked contractions on 2 separate days, with

  4. Soreness-related changes in three-dimensional running biomechanics following eccentric knee extensor exercise.

    Science.gov (United States)

    Paquette, Max R; Peel, Shelby A; Schilling, Brian K; Melcher, Dan A; Bloomer, Richard J

    2017-06-01

    Runners often experience delayed onset muscle soreness (DOMS), especially of the knee extensors, following prolonged running. Sagittal knee joint biomechanics are altered in the presence of knee extensor DOMS but it is unclear how muscle soreness affects lower limb biomechanics in other planes of motion. The purpose of this study was to assess the effects of knee extensor DOMS on three-dimensional (3D) lower limb biomechanics during running. Thirty-three healthy men (25.8 ± 6.8 years; 84.1 ± 9.2 kg; 1.77 ± 0.07 m) completed an isolated eccentric knee extensor damaging protocol to elicit DOMS. Biomechanics of over-ground running at a set speed of 3.35 m s -1 ±5% were measured before eccentric exercise (baseline) and, 24 h and 48 h following exercise in the presence of knee extensor DOMS. Knee flexion ROM was reduced at 48 h (P = 0.01; d = 0.26), and peak knee extensor moment was reduced at 24 h (P = 0.001; d = 0.49) and 48 h (P  0.05). Peak positive ankle and knee joint powers and, peak negative knee joint power were all reduced from baseline to 24 h and 48 h (P < 0.05). These findings suggest that knee extensor DOMS greatly influences sagittal knee joint angular kinetics and, reduces sagittal power production at the ankle joint. However, knee extensor DOMS does not affect frontal and transverse plane lower limb joint biomechanics during running.

  5. Limb symmetry during double-leg squats and single-leg squats on land and in water in adults with long-standing unilateral anterior knee pain; a cross sectional study.

    Science.gov (United States)

    Severin, Anna C; Burkett, Brendan J; McKean, Mark R; Wiegand, Aaron N; Sayers, Mark G L

    2017-01-01

    The presence of pain during movement typically results in changes in technique. However, the physical properties of water, such as flotation, means that water-based exercise may not only reduce compensatory movement patterns but also allow pain sufferers to complete exercises that they are unable to perform on land. The purpose of this study was to assess bilateral kinematics during double-leg squats and single-leg squats on land and in water in individuals with unilateral anterior knee pain. A secondary aim was to quantify bilateral asymmetry in both environments in affected and unaffected individuals using a symmetry index. Twenty individuals with unilateral knee pain and twenty healthy, matched controls performed body weight double- and single-leg squats in both environments while inertial sensors (100 Hz) recorded trunk and lower body kinematics. Repeated-measures statistics tested for environmental effects on movement depths and peak angles within the anterior knee pain group. Differences in their inter-limb symmetry in each environments was compared to the control group using analysis of variance tests. Water immersion allowed for greater movement depths during both exercises (double-leg squat: +7 cm, p  = 0.032, single-leg squat: +9 cm, p  = 0.002) for the knee pain group. The double-leg squat was symmetrical on land but water immersion revealed asymmetries in the lower body frontal plane movements. The single-leg squat revealed decreased hip flexion and frontal plane shank motions on the affected limb in both environments. Water immersion also affected the degree of lower limb asymmetry in both groups, with differences also showing between groups. Individuals with anterior knee pain achieved increased squat depth during both exercises whilst in water. Kinematic differences between the affected and unaffected limbs were often increased in water. Individuals with unilateral anterior knee pain appear to utilise different kinematics in the affected

  6. Knee extension range of motion and self-report physical function in total knee arthroplasty: mediating effects of knee extensor strength

    Directory of Open Access Journals (Sweden)

    Pua Yong-Hao

    2013-01-01

    Full Text Available Abstract Background Knee extensor strength and knee extension range of motion (ROM are important predictors of physical function in patients with a total knee arthroplasty (TKA. However, the relationship between the two knee measures remains unclear. The purpose of this study was to examine whether changes in knee extensor strength mediate the association between changes in knee extension ROM and self-report physical function. Methods Data from 441 patients with a TKA were collected preoperatively and 6 months postoperatively. Self-report measure of physical function was assessed by the Short Form 36 (SF-36 questionnaire. Knee extensor strength was measured by handheld dynamometry and knee extension ROM by goniometry. A bootstrapped cross product of coefficients approach was used to evaluate mediation effects. Results Mediation analyses, adjusted for clinicodemographic measures, revealed that the association between changes in knee extension ROM and SF-36 physical function was mediated by changes in knee extensor strength. Conclusions In patients with TKA, knee extensor strength mediated the influence of knee extension ROM on physical function. These results suggest that interventions to improve the range of knee extension may be useful in improving knee extensor performance.

  7. Knee extensor strength and body weight in adolescent men and the risk of knee osteoarthritis by middle age

    DEFF Research Database (Denmark)

    Turkiewicz, Aleksandra; Timpka, Simon; Thorlund, Jonas Bloch

    2017-01-01

    OBJECTIVES: To assess the extent to which knee extensor strength and weight in adolescence are associated with knee osteoarthritis (OA) by middle age. METHODS: We studied a cohort of 40 121 men who at age 18 years in 1969/1970 underwent mandatory conscription in Sweden. We retrieved data on isome......OBJECTIVES: To assess the extent to which knee extensor strength and weight in adolescence are associated with knee osteoarthritis (OA) by middle age. METHODS: We studied a cohort of 40 121 men who at age 18 years in 1969/1970 underwent mandatory conscription in Sweden. We retrieved data...... on isometric knee extensor strength, weight, height, smoking, alcohol consumption, parental education and adult occupation from Swedish registries. We identified participants diagnosed with knee OA or knee injury from 1987 to 2010 through the National Patient Register. We estimated the HR of knee OA using...... multivariable-adjusted Cox proportional regression model. To assess the influence of adult knee injury and occupation, we performed a formal mediation analysis. RESULTS: The mean (SD) knee extensor strength was 234 (47) Nm, the mean (SD) weight was 66 (9.3) kg. During 24 years (median) of follow-up starting...

  8. The effects of imagery on fast isometric knee extensor torque development

    NARCIS (Netherlands)

    de Ruiter, C.J.; Hutter, R.I.; Icke, C; Groen, B; Gemmink, A; Smilde, H; de Haan, A.

    2012-01-01

    We hypothesized that imagery training would improve fast onset of neuromuscular activation and thereby fast knee extensor isometric torque development. Forty young healthy participants not involved in strength training, were assigned to one of four groups: physical training, imagery training,

  9. The Effect of Visual Impairment on the Strength of Children's Hip and Knee Extensors.

    Science.gov (United States)

    Wyatt, L.; Ng, G. Y.

    1997-01-01

    A test of 32 children's hip and knee extensors found that children born blind or with low vision are at risk of developing weak lower-limb extensors, with congenitally blind children at greatest risk. After correcting for lean body weight, the differences between sighted children and those with low vision were insignificant. Results support the…

  10. Nonparetic knee extensor strength is the determinant of exercise capacity of community-dwelling stroke survivors.

    Science.gov (United States)

    Wang, Wei-Te; Huang, Ling-Tzu; Chou, Ya-Hui; Wei, Ta-Sen; Lin, Chung-Che

    2014-01-01

    To investigate the relationship among walking speed, exercise capacity, and leg strength in community dwelling stroke subjects and to evaluate which one was the leading determinant factor of them. This is a descriptive, cross-sectional study. Thirty-five chronic stroke patients who were able to walk independently in their community were enrolled. Walking speed was evaluated by using the 12-meter walking test. A maximal exercise test was used to determine the stroke subjects' exercise capacity. Knee extensor strength, measured as isokinetic torque, was assessed by isokinetic dynamometer. The main walking speed of our subjects was 0.52 m/s. Peak oxygen uptake (VO₂ peak) was 1.21 ± 0.43 L/min. Knee extensor strength, no matter whether paretic or nonparetic side, was significantly correlated to 12-meter walking speed and exercise capacity. Linear regression also showed the strength of the affected knee extensor was the determinant of walking speed and that of the nonparetic knee extensor was the determinant of exercise capacity in community dwelling stroke subjects. Walking speed and peak oxygen uptake were markedly decreased after stroke. Knee extensor strength of nonparetic leg was the most important determinant of exercise capacity of the community-dwelling stroke subjects. Knee extensor strengthening should be emphasized to help stroke patient to achieve optimal community living.

  11. Extensor Mechanism Disruption after Total Knee Arthroplasty: A Case Series and Review of Literature.

    Science.gov (United States)

    Vaishya, Raju; Agarwal, Amit Kumar; Vijay, Vipul

    2016-02-04

    Extensor mechanism disruption following total knee arthroplasty (TKA) is a rare but devastating complication. These patients may require revision of the implants, but even then, it may not be possible to restore the normal function of the knee after the disruption. The patterns of extensor mechanism disruption can broadly be classified into three types: suprapatellar (quadriceps tendon rupture), transpatellar (patellar fracture), or infrapatellar (patellar tendon rupture). Infrapatellar tendon ruptures are the worst injuries, as they carry maximum morbidity and are challenging to manage. The disruption of the extensor mechanism may occur either intra-operatively or in the immediate postoperative period due to an injury. The treatment of extensor mechanism complications after TKA may include either nonsurgical management or surgical intervention in the form of primary repair or reconstruction with autogenous, allogeneic, or synthetic substitutes. We have provided an algorithm for the management of extensor mechanism disruption after TKA.

  12. The isometric torque at which knee-extensor muscle reoxygenation stops.

    NARCIS (Netherlands)

    de Ruiter, C.J.; Goudsmit, J.F.; Tricht, J.A.; de Haan, A.

    2007-01-01

    PURPOSE: We investigated the knee-extensor torque at which reoxygenation (inflow of arterial blood) during an isometric contraction stopped, whether this torque depended on maximal torque capacity (MTC), and whether there were differences among the synergists. METHODS: Isometric knee-extension

  13. Enhanced spinal excitation from ankle flexors to knee extensors during walking in stroke patients

    DEFF Research Database (Denmark)

    Achache, V.; Mazevet, D.; Iglesias, C.

    2010-01-01

    OBJECTIVES: It is still unclear to what an extent altered reflex activity contributes to gait deficit following stroke. Spinal group I and group II excitations from ankle dorsiflexors to knee extensors were investigated during post-stroke walking. METHODS: Electrical stimulation was applied......: The spinal, presumed group II, excitation from ankle dorsiflexors to knee extensors is particularly enhanced during post-stroke walking probably due to plastic adaptations in the descending control. SIGNIFICANCE: This adaptation may help to stabilize the knee in early stance when the patients have recover...... ankle dorsiflexor functions....

  14. Knee extensor strength is associated with pressure pain thresholds in adults with fibromyalgia.

    Directory of Open Access Journals (Sweden)

    W Michael Hooten

    Full Text Available Individuals with fibromyalgia (FM have lower muscle strength and lower pressure pain thresholds (PPT. The primary aim of this study was to determine the associations between muscle strength and PPT in adults with FM to test the hypothesis that greater measures of muscle strength would be associated with greater values of PPT. Secondary aims included determining the effects of pain severity and the peak uptake of oxygen (VO2 on the associations between muscle strength and PPT.Knee extensor and flexor strength (N = 69 was measured in the dominant leg using a dynamometer, and PPT was assessed using an electronic algometer. Pain severity was determined using the Multidimensional Pain Inventory, and peak VO2 uptake was quantified using an electronically braked cycle ergometer.Univariable linear regression analysis demonstrated a significant association between PPT (dependent variable and isometric knee extensor (P<.001, isokinetic (60°/s knee extensor (P = .002, and isokinetic (60°/s knee flexor strength (P = .043. In a multiple variable linear regression analysis adjusted for age, sex, pain severity, body mass index and peak VO2 uptake, a significant association was found between PPT and isometric knee extensor strength (P = .008. In a similar multiple variable analysis, a significant association was found between PPT and isokinetic knee extensor strength (P = .044.Greater measures of isometric and isokinetic knee extensor strength were significantly associated with greater values of PPT in both univariable and multiple variable linear regression models.ClinicalTrials.gov NCT01253395.

  15. Neuromuscular knee joint control in adolescents with and without Generalised Joint Hypermobility during landing in the Single leg Hop for Distance test

    DEFF Research Database (Denmark)

    Junge, Tina; Juul-Kristensen, B; Thorlund, J B

    Severe knee injuries can occur due to biomechanical factors such as knee joint laxity. Generalised Joint Hypermobility (GJH) has been proposed as an intrinsic risk factor for knee injuries in adults and adolescents, as individuals with GJH often have knee joint hypermobility. Also, critical knee...

  16. Neuromuscular knee joint control in adolescents with and without Generalised Joint Hypermobility during landing in the Single leg Hop for Distance test

    DEFF Research Database (Denmark)

    Junge, Tina; Juul-Kristensen, B; Thorlund, J B

    2014-01-01

    Severe knee injuries can occur due to biomechanical factors such as knee joint laxity. Generalised Joint Hypermobility (GJH) has been proposed as an intrinsic risk factor for knee injuries in adults and adolescents, as individuals with GJH often have knee joint hypermobility. Also, critical knee...

  17. Neuromuscular knee joint control in adolescents with and without Generalised Joint Hypermobility during landing in the Single leg Hop for Distance test

    DEFF Research Database (Denmark)

    Junge, Tina; Juul-Kristensen, B; Bloch Thorlund, Jonas

    Severe knee injuries can occur due to biomechanical factors such as knee joint laxity. Generalised Joint Hypermobility (GJH) has been proposed as an intrinsic risk factor for knee injuries in adults and adolescents, as individuals with GJH often have knee joint hypermobility. Also, critical knee ...

  18. Recovery Kinetics of Knee Flexor and Extensor Strength after a Football Match

    Science.gov (United States)

    Draganidis, Dimitrios; Chatzinikolaou, Athanasios; Avloniti, Alexandra; Barbero-Álvarez, José C.; Mohr, Magni; Malliou, Paraskevi; Gourgoulis, Vassilios; Deli, Chariklia K.; Douroudos, Ioannis I.; Margonis, Konstantinos; Gioftsidou, Asimenia; Fouris, Andreas D.; Jamurtas, Athanasios Z.; Koutedakis, Yiannis; Fatouros, Ioannis G.

    2015-01-01

    We examined the temporal changes of isokinetic strength performance of knee flexor (KF) and extensor (KE) strength after a football match. Players were randomly assigned to a control (N = 14, participated only in measurements and practices) or an experimental group (N = 20, participated also in a football match). Participants trained daily during the two days after the match. Match and training overload was monitored with GPS devices. Venous blood was sampled and muscle damage was assessed pre-match, post-match and at 12h, 36h and 60h post-match. Isometric strength as well as eccentric and concentric peak torque of knee flexors and extensors in both limbs (dominant and non-dominant) were measured on an isokinetic dynamometer at baseline and at 12h, 36h and 60h after the match. Functional (KFecc/KEcon) and conventional (KFcon/KEcon) ratios were then calculated. Only eccentric peak torque of knee flexors declined at 60h after the match in the control group. In the experimental group: a) isometric strength of knee extensors and knee flexors declined (Pfootball-specific conditioning. Our data suggest that recovery kinetics of knee flexor and extensor strength after a football match demonstrate strength, limb and velocity specificity and may depend on match physical overload and players' physical conditioning level. PMID:26043222

  19. Efficacy of pre-operative quadriceps strength training on knee-extensor strength before and shortly following total knee arthroplasty

    DEFF Research Database (Denmark)

    Husted, Rasmus Skov; Troelsen, Anders; Thorborg, Kristian

    2018-01-01

    with an elastic exercise band following an initial exercise instruction. Adherence is objectively quantified using a sensor attached to the exercise band. The primary outcome will be the change in knee-extensor strength. Following the 12-week exercise period, the need for TKA surgery is re...

  20. The effects of imagery training on fast isometric knee extensor torque development

    NARCIS (Netherlands)

    de Ruiter, Cornelis J.; Hutter, Vana; Icke, Chris; Groen, Bart; Gemmink, Anne; Smilde, Hiltsje; de Haan, Arnold

    2012-01-01

    We hypothesized that imagery training would improve the fast onset of neuromuscular activation and thereby fast knee extensor isometric torque development. Forty young healthy participants, not involved in strength training, were assigned to one of four groups: physical training, imagery training,

  1. Tendon properties and muscle architecture for knee extensors and plantar flexors in boys and men.

    Science.gov (United States)

    Kubo, Keitaro; Teshima, Takanori; Ikebukuro, Toshihiro; Hirose, Norikazu; Tsunoda, Naoya

    2014-05-01

    The purpose of this study was to compare the elastic properties and size of tendinous structures and muscle architecture for knee extensors and plantar flexors in boys and men. Twenty-two early pubescent boys (9.6-12.7yrs) and 23 young adult men (19.8-26.2yrs) participated in this study. The maximal strain and thickness of tendinous structures for knee extensors and plantar flexors were measured using ultrasonography. In addition, the fascicle lengths of vastus lateralis and medial gastrocnemius muscles were measured. The maximal strain of tendinous structures for plantar flexors was significantly greater in boys than in men, while there was no difference in the maximal strain for knee extensors between the two groups. The relative thickness (to body mass(1/3)) of Achilles tendon was significantly greater in boys than in men, although there was no difference in that of patellar tendon between the two groups. The relative fascicle length (to limb length) of vastus lateralis muscle was significantly lower in boys than in men, although there was no difference in that of medial gastrocnemius muscle between the two groups. These results suggest that the amount of changes in the elastic properties and sizes of tendinous structures and in the fascicle lengths from early pubescence to maturity is different for different muscle groups (in particular, the knee extensors and the plantar flexors). Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. A Short Submaximal test to determine the fatigue threshold of knee extensors in young men

    NARCIS (Netherlands)

    de Ruiter, C.J.; Hamacher, P.; Wolfs, B.G.A.

    Purpose Recently, a fatigue threshold obtained during submaximal repetitive isometric knee extensor contractions was related to VO 2max measured during cycling and to exercise endurance. However, test duration is quite long (20-30 min in young people) to be of practical and possibly clinical use.

  3. Isokinetic dynamometry of the knee extensors and flexors in Iranian healthy males and females.

    Science.gov (United States)

    Rezaei, Mandana; Ebrahimi, Ismael; Vassaghi-Gharamaleki, Behnoush; Pirali, Milad; Mortaza, Niyousha; Malmir, Kazem; Ghasemi, Kobra; A Jamshidi, Ali

    2014-01-01

    This paper explores the gender-related bilateral differences of extensor and flexor torques of the knee joint at low and high angular velocities in Iranian healthy males and females. 70 healthy subjects (29 males (26.61±4.34 yrs and 41 females with average age of 23.07±3.70 yrs)) were participated in this study. Isokinetic peak torque values for knee extensors and flexors in concentric and eccentric contraction modes were measured and flexors and extensors strength ratios (HQR) computed among both dominant and non-dominant legs in lying position at 60 and 180°.s-1angular velocities. There was significant gender-velocity interactions detected for knee flexor to extensor strength ratios presenting that increasing velocity escaled this, ratios in females more than males (p0.05). Bilateral differences were found for eccentric flexor peak torques (p<0.05). By increasing velocity, peak torque values decreased and HQR was increased (p<0.05). Measurement procedures including test position is an important factor when interpreting genderrelated and bilateral differences of isokinetic knee strength ratios in healthy individuals.

  4. Isometric knee-extensor torque development and jump height in volleyball players

    NARCIS (Netherlands)

    de Ruiter, C.J.; Vermeulen, G.; Toussaint, H.M.; de Haan, A.

    2007-01-01

    PURPOSE: The goal of the present study was to determine the contribution of the intrinsic muscle properties and muscle activation of the knee extensors to the maximal rate of unilateral isometric torque development and to relate both factors to maximal bilateral jumping performance in experienced

  5. Knee extensor muscle strength in middle-aged and older individuals undergoing arthroscopic partial meniscectomy

    DEFF Research Database (Denmark)

    Hall, Michelle; Juhl, Carsten B; Lund, Hans

    2015-01-01

    a moderate reduction was again apparent at 4 years post-APM (SMD: -0.56, (-1.20-0.08) compared to controls. CONCLUSIONS: Our findings suggest that middle-aged and older individuals undergoing APM have reduced knee extensor muscle strength in the operated leg compared to control data. As meniscus pathology...

  6. Seasonal variation in isokinetic strength of knee flexors and extensors in soccer players

    Directory of Open Access Journals (Sweden)

    Michal Lehnert

    2015-06-01

    Full Text Available BACKGROUND: Muscle strength is an important factor in soccer from the performance and health perspective. There is a lack of knowledge about changes in muscle strength of the knee flexors and extensors and their ratios during annual training cycle. OBJECTIVES: The aim of this study was to evaluate the seasonal variability of the observed parameters of isokinetic strength of the knee flexors and extensors in soccer players, U19, from the performance and health perspective. METHODS: The strength of the knee flexors and extensors was measured in players U19 category (n = 9; the average age 18.5 ±0.4 years on the isokinetic dynamometer IsoMed 2000 in angular velocity 60° × s-1. Measurement was performed in concentric/concentric and excentric/excentric mode of muscle action at the beginning of the winter preparatory period, at the end of the preparatory period and at the end of the spring competitive period. Monitored parameters were absolute peak torque (PT, conventional H/Q ratio (H/QCON, functional H/Q ratio (H/QFUN and functional H/Q ratio in range 10-30° of knee flexion (H/QFUN_10-30. RESULTS: Significant change in PT (p < .05 was noted only in cases of the knee extensors of the nondominant leg in the concentric mode. The evaluation of imbalance of the knee flexors and extensors by H/QCON and H/QFUN ratios did not show any significant changes, but there was found a significant decrease of the H/QFUN_10-30 ratio in the dominant leg between measurements at the beginning and at the end of the winter preparatory period. CONCLUSIONS: The results of the current study indicate that throughout the monitored periods of the annual training cycle desirable changes in knee flexors and extensors strength did not occur. The values suggest the disruption of the dynamic stabilization of the knee joint and increase in injury risk. Different dynamics of the three observed ratios confirmed that they provide different information about the physical fitness of

  7. Isokinetic Evaluation of Knee Extensor/Flexor Muscle Strength in Behcet’s Patients

    Directory of Open Access Journals (Sweden)

    Bekir Durmus

    2015-10-01

    Full Text Available Background: Behçet’s disease (BD is an idiopathic, multisystemic, progressive disease. The purpose of this study is to compare the knee flexor and extensor isokinetic muscle strengths of Behcet’s patients with that of healthy subjects. Methods: Twenty-five (13 male and 12 female patients with BD and 25 (15 male and 10 female healthy individuals were included in the study. Velocities of 90°/sec, 120°/sec, and 150°/sec were used for the isokinetic muscle strength testing. Patients with active inflammatory knee arthritis were excluded. Peak torque (Nm and peak torque adjusted to body weight (% were taken into consideration for comparison between study groups. Results: Compared to healthy controls, there was a statistically significant decrease in both the bilateral knee extensor and flexor muscle isokinetic peak torques(Nm as well as the peak torques adjusted to body weight (% at velocities of 90°/sec, 120°/sec and 150°/sec in patients with BD (p < 0.05. However, there was no significant difference in the agonist-antagonist ratio of the isokinetic peak torques of knee muscles between the two groups. Conclusion: In light of these findings, we have concluded that both knee flexor and extensor isokinetic muscle strengths are lower in BD. We therefore recommend careful monitoring of patients with BD in terms of muscle strength.

  8. MUSCLE ACTIVITY RESPONSE TO EXTERNAL MOMENT DURING SINGLE-LEG DROP LANDING IN YOUNG BASKETBALL PLAYERS: THE IMPORTANCE OF BICEPS FEMORIS IN REDUCING INTERNAL ROTATION OF KNEE DURING LANDING

    Directory of Open Access Journals (Sweden)

    Meguru Fujii

    2012-06-01

    Full Text Available Internal tibial rotation with the knee close to full extension combined with valgus collapse during drop landing generally results in non-contact anterior cruciate ligament (ACL injury. The purpose of this study was to investigate the relationship between internal rotation of the knee and muscle activity from internal and external rotator muscles, and between the internal rotation of knee and externally applied loads on the knee during landing in collegiate basketball players. Our hypothesis was that the activity of biceps femoris muscle would be an important factor reducing internal knee rotation during landing. The subjects were 10 collegiate basketball students: 5 females and 5 males. The subjects performed a single-leg drop landing from a 25-cm height. Femoral and tibial kinematics were measured using a 3D optoelectronic tracking system during the drop landings, and then the knee angular motions were determined. Ground reaction forces and muscle activation patterns (lateral hamstring and medial hamstring were simultaneously measured and computed. Results indicated that lower peak internal tibial rotation angle at the time of landing was associated with greater lateral hamstring activity (r = -0.623, p < 0.001. When gender was considered, the statistically significant correlation remained only in females. There was no association between the peak internal tibial rotation angle and the knee internal rotation moment. Control of muscle activity in the lateral to medial hamstring would be an important factor in generating sufficient force to inhibit excessive internal rotation during landing. Strengthening the biceps femoris might mitigate the higher incidence of non-contact ACL injury in female athletes

  9. The relationship between spasticity and muscle volume of the knee extensors in children with cerebral palsy.

    Science.gov (United States)

    Pierce, Samuel R; Prosser, Laura A; Lee, Samuel C K; Lauer, Richard T

    2012-01-01

    The purpose of this study was to examine the relationship between spasticity and muscle volume in children with cerebral palsy (CP), using isokinetic dynamometry and magnetic resonance imaging. A retrospective sample of 8 children with diplegic CP was analyzed. One set of 10 passive knee flexion movements was completed at a velocity of 180° per second with concurrent surface electromyography of the medial hamstrings (MH) and vastus lateralis (VL) to assess knee extensor spasticity. Magnetic resonance imaging was used to measure maximum cross-sectional area and muscle volume of the quadriceps femoris. The quadriceps femoris muscle volume was positively correlated with MH reflex activity, VL reflex activity, MH/VL co-contraction, and peak knee extensor passive torque (P spasticity are associated with greater quadriceps muscle volume in children with spastic diplegic CP.

  10. Association between hip abductor function, rear-foot dynamic alignment, and dynamic knee valgus during single-leg squats and drop landings

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    Yoshinori Kagaya

    2015-06-01

    Conclusion: Dynamic hip mal-alignment might be associated with both greater KID and HOD, whereas rear-foot eversion is associated only with greater KID. Hip abductor and rear-foot dysfunction are important factors for dynamic knee valgus and thus evaluating DTT and HFT will help to prevent dynamic knee valgus.

  11. Sex differences in muscle morphology of the knee flexors and knee extensors.

    Science.gov (United States)

    Behan, Fearghal P; Maden-Wilkinson, Thomas M; Pain, Matt T G; Folland, Jonathan P

    2018-01-01

    Females experience higher risk of anterior cruciate ligament (ACL) injuries; males experience higher risk of hamstring strain injuries. Differences in injury may be partially due to sex differences in knee flexor (KF) to knee extensor (KE) muscle size ratio and the proportional size of constituent muscles. To compare the absolute and proportional size, and mass distribution, of individual KE and KF muscles, as well as overall size and balance (size ratio) of these muscle groups between the sexes. T1-weighted axial plane MR images (1.5T) of healthy untrained young males and females (32 vs 34) were acquired to determine thigh muscle anatomical cross-sectional area (ACSA). Maximal ACSA (ACSAmax) of constituent muscles, summated for KF and KE muscle groups, and the KF:KE ratio were calculated. Females had 25.3% smaller KE ACSAmax (70.9±12.1 vs 93.6±10.3 cm2; PKF ACSAmax than males (38.8±7.3cm2 vs 55.1±7.3cm2; PKF:KE ACSA ratio (P = 0.031). There were sex differences in the proportional size of 2/4 KE and 5/6 KF. In females, vastus lateralis (VL), biceps femoris long-head (BFlh) and semimembranosus (SM) were a greater proportion and sartorius (SA), gracilis (GR) and biceps femoris short-head (BFsh) a smaller proportion of their respective muscle groups compared to males (All PKF:KE ACSAmax ratio may contribute to increased risk of ACL injury in females. Sex discrepancies in absolute and proportional size of SA, GR, VL and BFlh may contribute further anatomical explanations for sex differences in injury incidence.

  12. Sex differences in muscle morphology of the knee flexors and knee extensors.

    Directory of Open Access Journals (Sweden)

    Fearghal P Behan

    Full Text Available Females experience higher risk of anterior cruciate ligament (ACL injuries; males experience higher risk of hamstring strain injuries. Differences in injury may be partially due to sex differences in knee flexor (KF to knee extensor (KE muscle size ratio and the proportional size of constituent muscles.To compare the absolute and proportional size, and mass distribution, of individual KE and KF muscles, as well as overall size and balance (size ratio of these muscle groups between the sexes.T1-weighted axial plane MR images (1.5T of healthy untrained young males and females (32 vs 34 were acquired to determine thigh muscle anatomical cross-sectional area (ACSA. Maximal ACSA (ACSAmax of constituent muscles, summated for KF and KE muscle groups, and the KF:KE ratio were calculated.Females had 25.3% smaller KE ACSAmax (70.9±12.1 vs 93.6±10.3 cm2; P<0.001 and 29.6% smaller KF ACSAmax than males (38.8±7.3cm2 vs 55.1±7.3cm2; P<0.001. Consequently, females had lower KF:KE ACSA ratio (P = 0.031. There were sex differences in the proportional size of 2/4 KE and 5/6 KF. In females, vastus lateralis (VL, biceps femoris long-head (BFlh and semimembranosus (SM were a greater proportion and sartorius (SA, gracilis (GR and biceps femoris short-head (BFsh a smaller proportion of their respective muscle groups compared to males (All P<0.05.Sex differences in KF:KE ACSAmax ratio may contribute to increased risk of ACL injury in females. Sex discrepancies in absolute and proportional size of SA, GR, VL and BFlh may contribute further anatomical explanations for sex differences in injury incidence.

  13. Recovery kinetics of knee flexor and extensor strength after a football match.

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    Dimitrios Draganidis

    Full Text Available We examined the temporal changes of isokinetic strength performance of knee flexor (KF and extensor (KE strength after a football match. Players were randomly assigned to a control (N = 14, participated only in measurements and practices or an experimental group (N = 20, participated also in a football match. Participants trained daily during the two days after the match. Match and training overload was monitored with GPS devices. Venous blood was sampled and muscle damage was assessed pre-match, post-match and at 12 h, 36 h and 60 h post-match. Isometric strength as well as eccentric and concentric peak torque of knee flexors and extensors in both limbs (dominant and non-dominant were measured on an isokinetic dynamometer at baseline and at 12 h, 36 h and 60 h after the match. Functional (KFecc/KEcon and conventional (KFcon/KEcon ratios were then calculated. Only eccentric peak torque of knee flexors declined at 60 h after the match in the control group. In the experimental group: a isometric strength of knee extensors and knee flexors declined (P<0.05 at 12 h (both limbs and 36 h (dominant limb only, b eccentric and concentric peak torque of knee extensors and flexors declined (P<0.05 in both limbs for 36 h at 60°/s and for 60 h at 180°/s with eccentric peak torque of knee flexors demonstrating a greater (P<0.05 reduction than concentric peak torque, c strength deterioration was greater (P<0.05 at 180°/s and in dominant limb, d the functional ratio was more sensitive to match-induced fatigue demonstrating a more prolonged decline. Discriminant and regression analysis revealed that strength deterioration and recovery may be related to the amount of eccentric actions performed during the match and athletes' football-specific conditioning. Our data suggest that recovery kinetics of knee flexor and extensor strength after a football match demonstrate strength, limb and velocity specificity and may depend on match physical overload and players

  14. Use of a portable motion analysis system for knee dynamic stability assessment in anterior cruciate ligament deficiency during single-legged hop landing

    Directory of Open Access Journals (Sweden)

    Man-Yi Yeung

    2016-07-01

    Conclusion: The altered knee kinematics in ACL-deficient patients can be revealed by a portable motion capture system, which may enable the clinical application of kinematic assessment in the evaluation of ACL deficiency.

  15. Muscle protein degradation and amino acid metabolism during prolonged knee-extensor exercise in humans

    DEFF Research Database (Denmark)

    Van Hall, Gerrit; Saltin, B; Wagenmakers, A J

    1999-01-01

    The aim of this study was to investigate whether prolonged one-leg knee-extensor exercise enhances net protein degradation in muscle with a normal or low glycogen content. Net amino acid production, as a measure of net protein degradation, was estimated from leg exchange and from changes...... acid production was also 10-fold higher during exercise compared with that at rest (difference not significant). The net production rates of threonine, glycine and tyrosine and of the sum of the non-metabolized amino acids were about 1.5-2.5-fold higher during exercise with the leg with a low glycogen...... in the concentrations of amino acids that are not metabolized in skeletal muscle. Experiments were performed at rest and during one-leg knee-extensor exercise in six subjects having one leg with a normal glycogen content and the other with a low glycogen content. Exercise was performed for 90 min at a workload of 60...

  16. Pilates increases the isokinetic muscular strength of the knee extensors and flexors in elderly women.

    Science.gov (United States)

    Oliveira, Laís Campos; Oliveira, Raphael Gonçalves; Pires-Oliveira, Deise Aparecida de Almeida

    2017-10-01

    Pilates has been shown to be effective for increasing muscle strength in older adults, however, some variables have not yet been explored. Investigate the effects of Pilates on the isokinetic muscular strength of the knee extensors and flexors at 60°/s, in elderly women. Thirty-two women were randomized into two groups: control group (CG, n = 16, age = 64.2 ± 0.8 years; BMI = 25.0 ± 1.2 kg/m 2 ), and experimental group (EG, n = 16, age = 63.6 ± 1.0 years, BMI = 24.7 ± 1.3 kg/m 2 ). Isokinetic evaluation of the knee extensor and flexor muscles was performed at 60°/s, pre- and post-intervention, considering the peak torque (N.m) and total work (J) for the right and left lower limbs. The CG participated in static stretching and the EG in Pilates sessions, twice a week for 12 weeks. The results demonstrated that the EG presented a significant improvement (p muscular strength of the knee extensors and flexors in elderly women and can be considered for this purpose when prescribing physical exercise programs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Acute Effects of Kinesio Taping on Knee Extensor Peak Torque and Stretch Reflex in Healthy Adults

    Science.gov (United States)

    Yeung, Simon S.; Yeung, Ella W.

    2016-01-01

    Abstract Kinesio Tex tape (KT) is used to prevent and treat sports-related injuries and to enhance muscle performance. It has been proposed that the direction of taping may either facilitate or inhibit the muscle by having different effects on cutaneous receptors that modulate excitability of the motor neurons. This study had 2 goals. First, we wished to determine if KT application affects muscle performance and if the method of application facilitates or inhibits muscle performance. This was assessed by measuring isokinetic knee extension peak torque in the knee extensor. Second, we assessed neurological effects of taping on the excitability of the motor neurons by measuring the reflex latency and action potential by electromyography (EMG) in the patellar reflex. The study was a single-blind, placebo-controlled crossover trial with 28 healthy volunteers with no history of knee injuries. Participants received facilitative KT treatment, inhibitory KT treatment, or Hypafix taping of the knee extensor. There were significant differences in the peak torque between 3 treatments (F(2,54) = 4.873, P < 0.01). Post hoc analysis revealed that facilitative KT treatment resulted in higher knee extensor peak torque performance than inhibitory KT treatment (P = 0.036, effect size 0.26). There were, however, no significant differences in the reflex latency (F(2,54) = 2.84, P = 0.067) nor in the EMG values (F(2,54) = 0.18, P = 0.837) in the patellar reflex between the 3 taping applications. The findings suggest that the direction of KT application over the muscle has specific effects on muscle performance. Given the magnitude of effect is small, interpretation of clinical significance should be considered with caution. The underlying mechanism warrants further investigation. PMID:26825916

  18. THE ASSOCIATIONS BETWEEN HIP STRENGTH AND HIP KINEMATICS DURING A SINGLE LEG HOP IN RECREATIONAL ATHLETES POST ACL RECONSTRUCTION COMPARED TO HEALTHY CONTROLS.

    Science.gov (United States)

    Tate, Jeremiah; Suckut, Tell; Wages, Jensen; Lyles, Heather; Perrin, Benjamin

    2017-06-01

    Only a small amount of evidence exists linking hip abductor weakness to dynamic knee valgus during static and dynamic activities. The associations of hip extensor strength and hip kinematics during the landing of a single leg hop are not known. Purpose: To determine if relationships exist between hip extensor and abductor strength and hip kinematics in both involved and uninvolved limb during the landing phase of a single leg hop in recreational athletes post anterior cruciate ligament (ACL) reconstruction. The presence of similar associations was also evaluated in healthy recreational athletes. Controlled Laboratory Study; Cross-sectional. Twenty-four recreational college-aged athletes participated in the study (12 post ACL reconstruction; 12 healthy controls). Sagittal and frontal plane hip kinematic data were collected for five trials during the landing of a single leg hop. Hip extensor and abductor isometric force production was measured using a hand-held dynamometer and normalized to participants' height and weight. Dependent and independent t-tests were used to analyze for any potential differences in hip strength or kinematics within and between groups, respectively. Pearson's r was used to demonstrate potential associations between hip strength and hip kinematics for both limbs in the ACL group and the right limb in the healthy control group. Independent t-tests revealed that participants post ACL reconstruction exhibited less hip extensor strength (0.18 N/Ht*BW vs. 0.25 N/Ht*BW, p=hip adduction (9.0 º vs. 0.8 º, p=hip extensor strength and maximum hip abduction/adduction angle in the involved limb. A moderate and direct relationship between hip abductor strength and maximum hip flexion angle was demonstrated in the both the involved ( r =.62) and uninvolved limb ( r =.65, p=.02). No significant associations were demonstrated between hip extensor or abductor strength and hip flexion and/or abduction/adduction angles in the healthy group. The

  19. Effect of Preactivation on Torque Enhancement by the Stretch-Shortening Cycle in Knee Extensors.

    Directory of Open Access Journals (Sweden)

    Atsuki Fukutani

    Full Text Available The stretch-shortening cycle is one of the most interesting topics in the field of sport sciences, because the performance of human movement is enhanced by the stretch-shortening cycle (eccentric contraction. The purpose of the present study was to examine whether the influence of preactivation on the torque enhancement by stretch-shortening cycle in knee extensors. Twelve men participated in this study. The following three conditions were conducted for knee extensors: (1 concentric contraction without preactivation (CON, (2 concentric contraction with eccentric preactivation (ECC, and (3 concentric contraction with isometric preactivation (ISO. Muscle contractions were evoked by electrical stimulation to discard the influence of neural activity. The range of motion of the knee joint was set from 80 to 140 degrees (full extension = 180 degrees. Angular velocities of the concentric and eccentric contractions were set at 180 and 90 degrees/s, respectively. In the concentric contraction phase, joint torques were recorded at 85, 95, and 105 degrees, and they were compared among the three conditions. In the early phase (85 degrees of concentric contraction, the joint torque was larger in the ECC and ISO conditions than in the CON condition. However, these clear differences disappeared in the later phase (105 degrees of concentric contraction. The results showed that joint torque was clearly different among the three conditions in the early phase whereas this difference disappeared in the later phase. Thus, preactivation, which is prominent in the early phase of contractions, plays an important role in torque enhancement by the stretch-shortening cycle in knee extensors.

  20. A Novel Two-Velocity Method for Elaborate Isokinetic Testing of Knee Extensors.

    Science.gov (United States)

    Grbic, Vladimir; Djuric, Sasa; Knezevic, Olivera M; Mirkov, Dragan M; Nedeljkovic, Aleksandar; Jaric, Slobodan

    2017-09-01

    Single outcomes of standard isokinetic dynamometry tests do not discern between various muscle mechanical capacities. In this study, we aimed to (1) evaluate the shape and strength of the force-velocity relationship of knee extensors, as observed in isokinetic tests conducted at a wide range of angular velocities, and (2) explore the concurrent validity of a simple 2-velocity method. Thirteen physically active females were tested for both the peak and averaged knee extensor concentric force exerted at the angular velocities of 30°-240°/s recorded in the 90°-170° range of knee extension. The results revealed strong (0.960knee extensors and, if supported by further research, other muscles. This brief and fatigue-free testing procedure could discern between muscle force, velocity, and power-producing capacities. © Georg Thieme Verlag KG Stuttgart · New York.

  1. Reduced rate of knee extensor torque development in older adults with knee osteoarthritis is associated with intrinsic muscle contractile deficits.

    Science.gov (United States)

    Callahan, Damien M; Tourville, Timothy W; Slauterbeck, James R; Ades, Philip A; Stevens-Lapsley, Jennifer; Beynnon, Bruce D; Toth, Michael J

    2015-12-01

    We examined the effect of knee osteoarthritis on the rate of torque development (RTD) of the knee extensors in older adults with advanced-stage knee osteoarthritis (OA; n=15) and recreationally-active controls (n=15) of similar age, sex and health status, as well as the relationship between RTD and the size and contractility of single muscle fibers. OA participants had lower RTD when expressed in absolute terms (Nm/ms). There were sex differences in peak RTD (Pmuscle, and was mitigated when RTD was normalized to peak torque (PT). In knee OA volunteers, we found strong correlations between the RTD expressed relative to PT and the velocity of contraction of single myosin heavy chain (MHC) I and IIA/X muscle fibers (r=0.652 and 0.862; both Pmuscle contractile kinetics in patients with advanced-stage knee osteoarthritis and healthy older adults is related, in part, to the size and function of single muscle fibers. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Reliability of contractile properties of the knee extensor muscles in individuals with post-polio syndrome.

    Directory of Open Access Journals (Sweden)

    Eric L Voorn

    Full Text Available To assess the reliability of contractile properties of the knee extensor muscles in 23 individuals with post-polio syndrome (PPS and 18 age-matched healthy individuals.Contractile properties of the knee extensors were assessed from repeated electrically evoked contractions on 2 separate days, with the use of a fixed dynamometer. Reliability was determined for fatigue resistance, rate of torque development (MRTD, and early and late relaxation time (RT50 and RT25, using the intraclass correlation coefficient (ICC and standard error of measurement (SEM, expressed as % of the mean.In both groups, reliability for fatigue resistance was good, with high ICCs (>0.90 and small SEM values (PPS: 7.1%, healthy individuals: 7.0%. Reliability for contractile speed indices varied, with the best values found for RT50 (ICCs>0.82, SEM values <2.8%. We found no systematic differences between test and retest occasions, except for RT50 in healthy subjects (p = 0.016.In PPS and healthy individuals, the reliability of fatigue resistance, as obtained from electrically evoked contractions is high. The reliability of contractile speed is only moderate, except for RT50 in PPS, demonstrating high reliability.This was the first study to examine the reliability of electrically evoked contractile properties in individuals with PPS. Our results demonstrate its potential to study mechanisms underlying muscle fatigue in PPS and to evaluate changes in contractile properties over time in response to interventions or from natural course.

  3. Reliability of contractile properties of the knee extensor muscles in individuals with post-polio syndrome.

    Science.gov (United States)

    Voorn, Eric L; Brehm, Merel A; Beelen, Anita; de Haan, Arnold; Nollet, Frans; Gerrits, Karin H L

    2014-01-01

    To assess the reliability of contractile properties of the knee extensor muscles in 23 individuals with post-polio syndrome (PPS) and 18 age-matched healthy individuals. Contractile properties of the knee extensors were assessed from repeated electrically evoked contractions on 2 separate days, with the use of a fixed dynamometer. Reliability was determined for fatigue resistance, rate of torque development (MRTD), and early and late relaxation time (RT50 and RT25), using the intraclass correlation coefficient (ICC) and standard error of measurement (SEM, expressed as % of the mean). In both groups, reliability for fatigue resistance was good, with high ICCs (>0.90) and small SEM values (PPS: 7.1%, healthy individuals: 7.0%). Reliability for contractile speed indices varied, with the best values found for RT50 (ICCs>0.82, SEM values <2.8%). We found no systematic differences between test and retest occasions, except for RT50 in healthy subjects (p = 0.016). In PPS and healthy individuals, the reliability of fatigue resistance, as obtained from electrically evoked contractions is high. The reliability of contractile speed is only moderate, except for RT50 in PPS, demonstrating high reliability. This was the first study to examine the reliability of electrically evoked contractile properties in individuals with PPS. Our results demonstrate its potential to study mechanisms underlying muscle fatigue in PPS and to evaluate changes in contractile properties over time in response to interventions or from natural course.

  4. β-alanine supplementation improves isometric endurance of the knee extensor muscles

    Directory of Open Access Journals (Sweden)

    Sale Craig

    2012-06-01

    Full Text Available Abstract Background We examined the effect of four weeks of β-alanine supplementation on isometric endurance of the knee extensors at 45% maximal voluntary isometric contraction (MVIC. Methods Thirteen males (age 23 ± 6 y; height 1.80 ± 0.05 m; body mass 81.0 ± 10.5 kg, matched for pre-supplementation isometric endurance, were allocated to either a placebo (n = 6 or β-alanine (n = 7; 6.4 g·d-1 over 4 weeks supplementation group. Participants completed an isometric knee extension test (IKET to fatigue, at an intensity of 45% MVIC, before and after supplementation. In addition, two habituation tests were completed in the week prior to the pre-supplementation test and a further practice test was completed in the week prior to the post-supplementation test. MVIC force, IKET hold-time, and impulse generated were recorded. Results IKET hold-time increased by 9.7 ± 9.4 s (13.2% and impulse by 3.7 ± 1.3 kN·s-1 (13.9% following β-alanine supplementation. These changes were significantly greater than those in the placebo group (IKET: t(11 = 2.9, p ≤0.05; impulse: t(11 = 3.1, p ≤ 0.05. There were no significant changes in MVIC force in either group. Conclusion Four weeks of β-alanine supplementation at 6.4 g·d-1 improved endurance capacity of the knee extensors at 45% MVIC, which most likely results from improved pH regulation within the muscle cell as a result of elevated muscle carnosine levels.

  5. Strength asymmetry of the knee extensors and physical activity in middle-aged women

    Directory of Open Access Journals (Sweden)

    Michal Lehnert

    2014-09-01

    Full Text Available Background: Differences between muscle strength and power of lower limbs is one of the factors associated with falls in the elderly population. Muscle strength asymmetry of lower limbs increases with age. Objective: The aim of the study is to assess differences in the volume and intensity of physical activity (PA in the subgroups of women being at higher and lower risk of falls (with and without strength asymmetry of the knee extensors of dominant and non-dominant lower limb. Methods: Data from 42 women (age 56.3 ± 4.4 years; weight 76.5 ± 16.1 kg; body height 164.3 ± 5.2 cm; body mass index 28.1 ± 5.3 kg . m-2 were used for the purpose of the presented analysis. Furthermore the sample was divided into subgroups with lower and higher strength asymmetry of quadriceps muscle (as a criterion the asymmetry greater than 15% was chosen. Absolute concentric peak torque of the knee extensors was evaluated by an isokinetic dynamometer IsoMed 2000 in a sitting position at angular velocity of 180° . s-1. PA was monitored using Yamax SW-700 pedometers throughout 7 consecutive days and using the Czech version of standardized International Physical Activity Questionnaire. Results: Statistically significant differences between groups with lower and higher strength asymmetry were found in the amount of self-reported vigorous PA (p = .04; d = 0.6 only. Differences between the observed groups were not significant in self-reported moderate PA and walking. There were also no significant differences in the daily numbers of steps measured objectively. Conclusions: The results of the study indicate that from the point of view of strength asymmetry of knee extensors as a factor associated with falls in middle-aged women, intensity of PA could be an important characteristic of PA. This suggestion should be taken into account in habitual PA and training programs in middle-aged population.

  6. The relationship between knee joint angle and knee flexor and extensor muscle strength.

    Science.gov (United States)

    Ha, Misook; Han, Dongwook

    2017-04-01

    [Purpose] The aim of this study was to determine a relationship between joint angle and muscular strength. In particular, this research investigated the differences in maximum muscular strength and average muscular strength at the knee-joint posture. [Subjects and Methods] The study subjects comprised eight female students in their 20s attending S University in Busan. None of the subjects had functional disabilities or had experienced damage to the lower extremities in terms of measurement of muscular strength. A BIODEX system III model (Biodex medical system, USA) was used to measure joint angles and muscular strength. The axis of the dynamometer was consistent with the axis of motion, and measurements were made at 25° and 67° to examine differences in maximum muscular strength according to joint angle. [Results] The maximum muscular strength both knee-joint extension value, at 67° and flexion value, at 25° the value was larger. The average muscular strength both knee-joint extension value, at 67° and flexion value, at 25° the value was larger. [Conclusion] The results of this study reveal that muscular strength does not reach maximum at particular range angles, such as the knee-joint resting posture angle or the knee-joint middle range angle. Rather, a stretched muscle is stronger than a contracted muscle. Therefore, it is considered that it will be necessary to study the effects of the joint change ratio on muscular strength on the basis of the maximum stretched muscle.

  7. Sit-to-Stand Movement in Children with Hemiplegic Cerebral Palsy: Relationship with Knee Extensor Torque and Social Participation

    Science.gov (United States)

    dos Santos, Adriana Neves; Pavao, Silvia Leticia; Santiago, Paulo Roberto Pereira; Salvini, Tania de Fatima; Rocha, Nelci Adriana Cicuto Ferreira

    2013-01-01

    This study aimed to investigate the relationship between sit-to-stand (STS) movement, knee extensor torque and social participation in children with cerebral palsy (CP). Seven spastic hemiplegic CP patients (8.0 plus or minus 2.2 years), classified by the Gross Motor Function Classification System as I and II, and 18 typical children (8.4 plus or…

  8. Functional Strength Training Effects on Knee Flexors and Extensors Power Output in Football Players

    Directory of Open Access Journals (Sweden)

    Izet Radjo

    2016-06-01

    Full Text Available Study aim was to compare and reevaluate effects of additional strength training program in football players after eight week application. Program was design to increase power and strength of knee extensors and flexors using neuromuscular adaptation. In overall, 18 senior level football players completed intervention in preparation period executing program as part of warm up 2-3 times per week. Using t-test for dependent samples statistical significance of the possible change was evaluated in peak torque, total and average work changes measured using Biodex isokinetic dynamometer. All measuring procedures were done for both limbs. Results are suggesting that statistically significant change observed in both limbs for the peak power output and average work load in flexion and extension, respectively. Other research papers are suggesting that increase of power and strength of knee muscles can help in preventing of injurie occurrence. LCA injurie can be prevention when femoral biceps strength is increase. This training modality based on neuromuscular adaptation is noninvasive with good effects in performance increase. Using training loads with body weight intensity is a good way to establish prevention to possible knee injurie with simultaneous power increase, with minimum of chance to reach unwanted overtraining.

  9. Placebo effects of caffeine on maximal voluntary concentric force of the knee flexors and extensors.

    Science.gov (United States)

    Tallis, Jason; Muhammad, Bilal; Islam, Mohammed; Duncan, Michael J

    2016-09-01

    We examined the placebo effect of caffeine and the combined effect of caffeine and caffeine expectancy on maximal voluntary strength. Fourteen men completed 4 randomized, single-blind experimental trials: (1) told caffeine, given caffeine (5 mg/kg) (CC); (2) told caffeine, given placebo (CP); (3) told placebo, given placebo (PP); and (4) told placebo, given caffeine (PC). Maximal voluntary concentric force and fatigue resistance of the knee flexors and extensors were measured using isokinetic dynamometry. A significant and equal improvement in peak concentric force was found in the CC and PC trials. Despite participants believing caffeine would evoke a performance benefit, there was no effect of CP. Caffeine caused an improvement in some aspects of muscle strength, but there was no additional effect of expectancy. Performance was poorer in participants who believed caffeine would have the greatest benefit, which highlights a link between expected ergogenicity, motivation, and personality characteristics. Muscle Nerve 54: 479-486, 2016. © 2015 Wiley Periodicals, Inc.

  10. Modulation of recurrent inhibition from knee extensors to ankle motoneurones during human walking

    DEFF Research Database (Denmark)

    Lamy, Jean-Charles; Iglesias, Caroline; Lackmy, Alexandra

    2008-01-01

    The neural control for muscle coordination during human locomotion involves spinal and supraspinal networks, but little is known about the exact mechanisms implicated. The present study focused on modulation of heteronymous recurrent inhibition from knee extensors to ankle motoneurones at different...... times in the gait cycle, when quadriceps (Quad) muscle activity overlaps that in tibialis anterior (TA) and soleus (Sol). The effects of femoral nerve stimulation on ankle motoneurones were investigated during treadmill walking and during tonic co-contraction of Quad and TA/Sol while standing. Recurrent...... inhibition of TA motoneurones depended on the level of background EMG, and was similar during walking and standing for matched background EMG levels. On the other hand, recurrent inhibition in Sol was reduced in early stance, with respect to standing, and enhanced in late stance. Reduced inhibition in Sol...

  11. Use of Leeds-Keio connective tissue prosthesis (L-K CTP) for reconstruction of deficient extensor mechanism with total knee replacement.

    Science.gov (United States)

    Sherief, Tamer I; Naguib, Ashraf M; Sefton, Graham K

    2005-08-01

    This study was carried out in order to assess the results of reconstruction of a deficient extensor mechanism in the presence of a total knee replacement (TKR) using the Leeds-Keio Connective Tissue Prosthesis (L-K CTP). The L-K CTP is available as flat tapes constructed from polyester in an open weave structure. It was used to reinforce and reconstruct the extensor mechanism, which was deficient in three patients who had undergone total knee replacement or were about to undergo total knee replacement. Two cases had extensor mechanism deficiency as a complication following total knee replacement while the third case had extensor mechanism deficiency at the time of the primary knee replacement. The average follow-up was 2 years (range of follow up was 12 to 48 months). All three cases showed good results with no extension lag and good range of movement at follow up. The use of L-K CTP for reconstruction of the knee extensor mechanism offers a good option for the management of the uncommon but difficult problem of extensor mechanism deficiency in patients with a total knee replacement.

  12. Examination of Spasticity of the Knee Flexors and Knee Extensors Using Isokinetic Dynamometry With Electromyography and Clinical Scales in Children With Spinal Cord Injury

    Science.gov (United States)

    Pierce, Samuel R; Johnston, Therese E; Shewokis, Patricia A; Lauer, Richard T

    2008-01-01

    Background/Objective: To examine the role of reflex activity in spasticity and the relationship between peak passive torque, Ashworth Scale (AS), and Spasm Frequency Scale (SFS) of the knee flexors and extensors during the measurement of spasticity using an isokinetic dynamometer in children with spinal cord injury (SCI). Methods: Eighteen children with chronic SCI and 10 children of typical development (TD) participated. One set of 10 passive movements was completed using an isokinetic dynamometer at 15, 90, and 180 degrees per second (deg/s) while surface electromyographic data were collected from the vastus lateralis (VL) and medial hamstrings (MH). Spasticity was clinically assessed using the AS and SFS. Results: There were no significant differences in peak passive torque of the knee flexors and extensors at any velocity for children with SCI compared to children with TD. Children with TD demonstrated significantly more reflex activity of the MH during the assessment of knee flexor spasticity at all movement velocities than did children with SCI. Children with TD demonstrated significantly more reflex activity of the VL during the assessment of knee-extensor spasticity with movements at 180 deg/s. The relationship between peak passive torque, AS, and SFS was significant during movements at a velocity of 90 deg/s only. Conclusions: The role of increased reflexes in spasticity needs further examination. Isokinetic dynamometry may be measuring a different aspect of spasticity than the AS and SFS do in children with SCI. PMID:18581670

  13. Influence of acetaminophen and ibuprofen on in vivo patellar tendon adaptations to knee extensor resistance exercise in older adults

    DEFF Research Database (Denmark)

    Carroll, C C; Dickinson, J M; LeMoine, J K

    2011-01-01

    . These responses were generally uninfluenced by ibuprofen consumption. In the acetaminophen group, tendon deformation and strain increased 20% (P knee extensor resistance training in older...... training. Thirty-six individuals were randomly assigned to a placebo (67 ± 2 yr old), acetaminophen (64 ± 1 yr old; 4,000 mg/day), or ibuprofen (64 ± 1 yr old; 1,200 mg/day) group in a double-blind manner and completed 12 wk of knee extensor resistance training. Before and after training in vivo patellar...... tendon properties were assessed with MRI [cross-sectional area (CSA) and signal intensity] and ultrasonography of patellar tendon deformation coupled with force measurements to obtain stiffness, modulus, stress, and strain. Mean patellar tendon CSA was unchanged (P > 0.05) with training in the placebo...

  14. Superior Effects of Eccentric to Concentric Knee Extensor Resistance Training on Physical Fitness, Insulin Sensitivity and Lipid Profiles of Elderly Men

    OpenAIRE

    Chen, Trevor Chung-Ching; Tseng, Wei-Chin; Huang, Guan-Ling; Chen, Hsin-Lian; Tseng, Kuo-Wei; Nosaka, Kazunori

    2017-01-01

    It has been reported that eccentric training of knee extensors is effective for improving blood insulin sensitivity and lipid profiles to a greater extent than concentric training in young women. However, it is not known whether this is also the case for elderly individuals. Thus, the present study tested the hypothesis that eccentric training of the knee extensors would improve physical function and health parameters (e.g., blood lipid profiles) of older adults better than concentric trainin...

  15. Bilateral knee extensor fatigue modulates force and responsiveness of the corticospinal pathway in thenon-fatigued, dominant elbow flexors

    Directory of Open Access Journals (Sweden)

    Nemanja eŠambaher

    2016-02-01

    Full Text Available Exercise-induced fatigue affects muscle performance and modulates corticospinal excitability in non-exercised muscles. The purpose of this study was to investigate the effect of bilateral knee extensor fatigue on dominant elbow flexor (EF maximal voluntary force production and corticospinal excitability. Transcranial magnetic, transmastoid electrical and brachial plexus electrical stimulation were used to investigate corticospinal, spinal, and muscle excitability of the dominant EF before and after a bilateral knee extensor fatiguing protocol or time matched rest period (control. For both sessions three stimuli were delivered every 1.5s during the three pre-test time points and during the 1st, 3rd, 6th, 9th and 12th post-test 5s EF isometric maximal voluntary contractions (MVC. In both conditions, Overall, EF MVC force (p< 0.001 decreased progressively from repetition #1 to #12 during the post-test MVC protocol. EF MVC force (p < 0.001, ES = 0.9, ∆ 10.3% decrements were more pronounced in the knee extensor fatigue intervention condition. In addition, there were no significant differences between conditions for biceps brachii electromyographic (EMG activity (p = 0.43, motor evoked potentials (MEP amplitude (p=0.908 or MEP silent period (p=0.776. However, the fatigue condition exhibited a lower MEP/ cervico-medullary MEP (CMEP ratio (p=0.042, ES=2.5, ∆25% and a trend toward higher CMEP values (p=0.08, ES=0.5, ∆20.4%. These findings suggest that bilateral knee extensor fatigue can impair performance and modulate corticospinal excitability of the EF.

  16. The interaction between the vastus medialis and vastus intermedius and its influence on the extensor apparatus of the knee joint.

    Science.gov (United States)

    Grob, Karl; Manestar, Mirjana; Filgueira, Luis; Kuster, Markus S; Gilbey, Helen; Ackland, Timothy

    2018-03-01

    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. Effects of strength training and detraining on knee extensor strength, muscle volume and muscle quality in elderly women.

    Science.gov (United States)

    Correa, Cleiton Silva; Baroni, Bruno Manfredini; Radaelli, Régis; Lanferdini, Fábio Juner; Cunha, Giovani dos Santos; Reischak-Oliveira, Álvaro; Vaz, Marco Aurélio; Pinto, Ronei Silveira

    2013-10-01

    Strength training seems to be an interesting approach to counteract decreases that affect knee extensor strength, muscle mass and muscle quality (force per unit of muscle mass) associated with ageing. However, there is no consensus regarding the changes in muscle mass and their contribution to strength during periods of training and detraining in the elderly. Therefore, this study aimed at verifying the behaviour of knee extensor muscle strength, muscle volume and muscle quality in elderly women in response to a 12-week strength training programme followed by a similar period of detraining. Statistical analysis showed no effect of time on muscle quality. However, strength and muscle volume increased from baseline to post-training (33 and 26 %, respectively). After detraining, the knee extensor strength remained 12 % superior to the baseline values, while the gains in muscle mass were almost completely lost. In conclusion, strength gains and losses due to strength training and detraining, respectively, could not be exclusively associated with muscle mass increases. Training-induced strength gains were partially maintained after 3 months of detraining in elderly subjects.

  18. Isokinetic performance of knee flexor and extensor muscles in community-dwelling elderly women

    Directory of Open Access Journals (Sweden)

    Diogo C. Felício

    Full Text Available AbstractIntroduction The isokinetic dynamometer enables accurate assessment of muscle function. In Brazil, few studies have assessed the isokinetic muscle performance in older adults making interpretation and comparison of results with other studies.Objectives To conduct a descriptive analysis of the performance of the muscle flexor and extensor muscles of the knee joint in elderly community and compare the performance between the age groups 65-74 years and 75 years or more.Methods This is a cross sectional observational study with a convenience sample of 229 elderly community. For the analysis of muscle performance was used isokinetic dynamometer (Biodex System 3 Pro™ in the angular velocities of 60 °/s and 180 °/s. The variables evaluated were peak torque, peak torque normalized by body weight, total work normalized by body mass, total work, average power and agonist/antagonist ratio. Descriptive analysis was used to characterize the sample. For comparison between age groups was used Student's t-test with α = 0.05.Results The elderly women with older age showed a statistically significant decrease in most of the variables (p < 0.05 except for the agonist and antagonist knee (p = 0.398.Conclusions The isokinetic was a sensitive tool to characterize the modifications caused by aging on muscle function. Elderly with results below the lower limits of the confidence intervals for all variables certainly has a decreased strength for the age group evaluated and must be addressed therapeutically. The results can be used as a benchmark in clinical practice and future research.

  19. Functional and morphological adaptations to aging in knee extensor muscles of physically active men.

    Science.gov (United States)

    Baroni, Bruno Manfredini; Geremia, Jeam Marcel; Rodrigues, Rodrigo; Borges, Marcelo Krás; Jinha, Azim; Herzog, Walter; Vaz, Marco Aurélio

    2013-10-01

    It is not known if a physically active lifestyle, without systematic training, is sufficient to combat age-related muscle and strength loss. Therefore, the purpose of this study was to evaluate if the maintenance of a physically active lifestyle prevents muscle impairments due to aging. To address this issue, we evaluated 33 healthy men with similar physical activity levels (IPAQ = 2) across a large range of ages. Functional (torque-angle and torque-velocity relations) and morphological (vastus lateralis muscle architecture) properties of the knee extensor muscles were assessed and compared between three age groups: young adults (30 ± 6 y), middle-aged subjects (50 ± 7 y) and elderly subjects (69 ± 5 y). Isometric peak torques were significantly lower (30% to 36%) in elderly group subjects compared with the young adults. Concentric peak torques were significantly lower in the middle aged (18% to 32%) and elderly group (40% to 53%) compared with the young adults. Vastus lateralis thickness and fascicles lengths were significantly smaller in the elderly group subjects (15.8 ± 3.9 mm; 99.1 ± 25.8 mm) compared with the young adults (19.8 ± 3.6 mm; 152.1 ± 42.0 mm). These findings suggest that a physically active lifestyle, without systematic training, is not sufficient to avoid loss of strength and muscle mass with aging.

  20. Sex Differences in Neuromuscular Fatigability of the Knee Extensors Post-Stroke

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    Meghan Kirking

    2017-01-01

    Full Text Available Background and Purpose: Despite the implications of optimizing strength training post-stroke, little is known about the differences in fatigability between men and women with chronic stroke. The purpose of this study was to determine the sex differences in knee extensor muscle fatigability and potential mechanisms in individuals with stroke. Methods: Eighteen participants (10 men, eight women with chronic stroke (≥6 months and 23 (12 men, 11 women nonstroke controls participated in the study. Participants performed an intermittent isometric contraction task (6 s contraction, 3 s rest at 30% of maximal voluntary contraction (MVC torque until failure to maintain the target torque. Electromyography was used to determine muscle activation and contractile properties were assessed with electrical stimulation of the quadriceps muscles. Results: Individuals with stroke had a briefer task duration (greater fatigability than nonstroke individuals (24.1 ± 17 min vs. 34.9 ± 16 min. Men were more fatigable than women for both nonstroke controls and individuals with stroke (17.9 ± 9 min vs. 41.6 ± 15 min. Individuals with stroke had less fatigue-related changes in muscle contractile properties and women with stroke differed in their muscle activation strategy during the fatiguing contractions. Conclusions: Men and women fatigue differently post-stroke and this may be due to the way they neurally activate muscle groups.

  1. Effect of mental fatigue on induced tremor in human knee extensors.

    Science.gov (United States)

    Budini, Francesco; Lowery, Madeleine; Durbaba, Rade; De Vito, Giuseppe

    2014-06-01

    In this study, the effects of mental fatigue on mechanically induced tremor at both a low (3-6Hz) and high (8-12Hz) frequency were investigated. The two distinct tremor frequencies were evoked using two springs of different stiffness, during 20s sustained contractions of the knee extensor muscles at 30% maximum voluntary contraction (MVC) before and after 100min of a mental fatigue task, in 12 healthy (29±3.7years) participants. Mental fatigue resulted in a 6.9% decrease in MVC and in a 9.4% decrease in the amplitude of the agonist muscle EMG during sustained 30% MVC contractions in the induced high frequency only. Following the mental fatigue task, the coefficient of variation and standard deviation of the force signal decreased at 8-12Hz induced tremor by 31.7% and 35.2% respectively, but not at 3-6Hz induced tremor. Similarly, the maximum value and area underneath the peak in the power spectrum of the force signal decreased by 55.5% and 53.1% respectively in the 8-12Hz range only. In conclusion, mental fatigue decreased mechanically induced 8-12Hz tremor and had no effect on induced 3-6Hz tremor. We suggest that the reduction could be attributed to the decreased activation of the agonist muscles. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Fatigue resistance of the knee extensor muscles is not reduced in post-polio syndrome.

    Science.gov (United States)

    Voorn, Eric L; Beelen, Anita; Gerrits, Karin H L; Nollet, Frans; de Haan, Arnold

    2013-11-01

    The present study investigated whether intrinsic fatigability of the muscle fibers is reduced in patients with post-polio syndrome (PPS). This may contribute to the muscle fatigue complaints reported by patients with PPS. For this purpose, we assessed contractile properties and fatigue resistance of the knee extensor muscles using repeated isometric electrically evoked contractions in 38 patients with PPS and 19 age-matched healthy subjects. To determine whether any difference in fatigue resistance between both groups could be attributed to differences in aerobic capacity of the muscle fibers, 9 patients with PPS and 11 healthy subjects performed the same protocol under arterial occlusion. Results showed that fatigue resistance of patients with PPS was comparable to that in controls, both in the situation with intact circulation and with occluded blood flow. Together, our findings suggest that there are no differences in contractile properties and aerobic muscle capacity that may account for the increased muscle fatigue perceived in PPS. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Effects of endurance training on the maximal voluntary activation level of the knee extensor muscles.

    Science.gov (United States)

    Zghal, F; Martin, V; Thorkani, A; Arnal, P J; Tabka, Z; Cottin, F

    2014-04-01

    The aim of this study was to investigate the neural adaptations to endurance training, and more specifically the adaptation of the cortical voluntary activation of the knee extensor (KE) muscles. Sixteen sedentary men were randomly allocated into an endurance training (n = 8) or a control group (n = 8). All subjects performed a maximal aerobic speed test (MAS) before and immediately after the training period. Training lasted 8 weeks and was based on endurance running. During Pre- and Post-training testing sessions, maximal voluntary contraction (MVC) was measured and voluntary activation (VA) was calculated via peripheral nerve (PNS) and transcranial magnetic stimulations (TMS) superimposed to MVC. Electromyographic activity (EMG) of the KE muscles was also measured during MVC, PNS (M-wave) and TMS (motor evoked potentials-MEP). The cortical silent period following TMS was also assessed. Despite a significant improvement in endurance running performance, as suggested by the increase of MAS in the training group (Pre 15.4 ± 1.6 vs. Post 16.4 ± 1.6 km·h(-1)), endurance training did not affect MVC or VA as measured with PNS and TMS. Similarly, the EMG of KE muscles during MVC did not show any significant changes. Furthermore, the MEP amplitude and the duration of the silent period also remained unchanged after endurance training. The present study suggests an 8-week endurance-training program does not generate adaptations of neural factors in sedentary subjects.

  4. Propulsion phase of the single leg triple hop test in women with patellofemoral pain syndrome: a biomechanical study.

    Directory of Open Access Journals (Sweden)

    Andre Serra Bley

    Full Text Available Asymmetry in the alignment of the lower limbs during weight-bearing activities is associated with patellofemoral pain syndrome (PFPS, caused by an increase in patellofemoral (PF joint stress. High neuromuscular demands are placed on the lower limb during the propulsion phase of the single leg triple hop test (SLTHT, which may influence biomechanical behavior. The aim of the present cross-sectional study was to compare kinematic, kinetic and muscle activity in the trunk and lower limb during propulsion in the SLTHT using women with PFPS and pain free controls. The following measurements were made using 20 women with PFPS and 20 controls during propulsion in the SLTHT: kinematics of the trunk, pelvis, hip, and knee; kinetics of the hip, knee and ankle; and muscle activation of the gluteus maximus (GM, gluteus medius (GMed, biceps femoris (BF and vastus lateralis (VL. Differences between groups were calculated using three separate sets of multivariate analysis of variance for kinematics, kinetics, and electromyographic data. Women with PFPS exhibited ipsilateral trunk lean; greater trunk flexion; greater contralateral pelvic drop; greater hip adduction and internal rotation; greater ankle pronation; greater internal hip abductor and ankle supinator moments; lower internal hip, knee and ankle extensor moments; and greater GM, GMed, BL, and VL muscle activity. The results of the present study are related to abnormal movement patterns in women with PFPS. We speculated that these findings constitute strategies to control a deficient dynamic alignment of the trunk and lower limb and to avoid PF pain. However, the greater BF and VL activity and the extensor pattern found for the hip, knee, and ankle of women with PFPS may contribute to increased PF stress.

  5. Propulsion Phase of the Single Leg Triple Hop Test in Women with Patellofemoral Pain Syndrome: A Biomechanical Study

    Science.gov (United States)

    Bley, Andre Serra; Correa, João Carlos Ferrari; Reis, Amir Curcio Dos; Rabelo, Nayra Deise Dos Anjos; Marchetti, Paulo Henrique; Lucareli, Paulo Roberto Garcia

    2014-01-01

    Asymmetry in the alignment of the lower limbs during weight-bearing activities is associated with patellofemoral pain syndrome (PFPS), caused by an increase in patellofemoral (PF) joint stress. High neuromuscular demands are placed on the lower limb during the propulsion phase of the single leg triple hop test (SLTHT), which may influence biomechanical behavior. The aim of the present cross-sectional study was to compare kinematic, kinetic and muscle activity in the trunk and lower limb during propulsion in the SLTHT using women with PFPS and pain free controls. The following measurements were made using 20 women with PFPS and 20 controls during propulsion in the SLTHT: kinematics of the trunk, pelvis, hip, and knee; kinetics of the hip, knee and ankle; and muscle activation of the gluteus maximus (GM), gluteus medius (GMed), biceps femoris (BF) and vastus lateralis (VL). Differences between groups were calculated using three separate sets of multivariate analysis of variance for kinematics, kinetics, and electromyographic data. Women with PFPS exhibited ipsilateral trunk lean; greater trunk flexion; greater contralateral pelvic drop; greater hip adduction and internal rotation; greater ankle pronation; greater internal hip abductor and ankle supinator moments; lower internal hip, knee and ankle extensor moments; and greater GM, GMed, BL, and VL muscle activity. The results of the present study are related to abnormal movement patterns in women with PFPS. We speculated that these findings constitute strategies to control a deficient dynamic alignment of the trunk and lower limb and to avoid PF pain. However, the greater BF and VL activity and the extensor pattern found for the hip, knee, and ankle of women with PFPS may contribute to increased PF stress. PMID:24830289

  6. Effect of acute dietary nitrate intake on maximal knee extensor speed and power in healthy men and women.

    Science.gov (United States)

    Coggan, Andrew R; Leibowitz, Joshua L; Kadkhodayan, Ana; Thomas, Deepak P; Ramamurthy, Sujata; Spearie, Catherine Anderson; Waller, Suzanne; Farmer, Marsha; Peterson, Linda R

    2015-08-01

    Nitric oxide (NO) has been demonstrated to enhance the maximal shortening velocity and maximal power of rodent muscle. Dietary nitrate (NO3(-)) intake has been demonstrated to increase NO bioavailability in humans. We therefore hypothesized that acute dietary NO3(-) intake (in the form of a concentrated beetroot juice (BRJ) supplement) would improve muscle speed and power in humans. To test this hypothesis, healthy men and women (n = 12; age = 22-50 y) were studied using a randomized, double-blind, placebo-controlled crossover design. After an overnight fast, subjects ingested 140 mL of BRJ either containing or devoid of 11.2 mmol of NO3(-). After 2 h, knee extensor contractile function was assessed using a Biodex 4 isokinetic dynamometer. Breath NO levels were also measured periodically using a Niox Mino analyzer as a biomarker of whole-body NO production. No significant changes in breath NO were observed in the placebo trial, whereas breath NO rose by 61% (P effect size = 1.19) after dietary NO3(-) intake. This was accompanied by a 4% (P effect size = 0.74) increase in peak knee extensor power at the highest angular velocity tested (i.e., 6.28 rad/s). Calculated maximal knee extensor power was therefore greater (i.e., 7.90 ± 0.59 vs. 7.44 ± 0.53 W/kg; P effect size = 0.63) after dietary NO3(-) intake, as was the calculated maximal velocity (i.e., 14.5 ± 0.9 vs. 13.1 ± 0.8 rad/s; P effect size = 0.67). No differences in muscle function were observed during 50 consecutive knee extensions performed at 3.14 rad/s. We conclude that acute dietary NO3(-) intake increases whole-body NO production and muscle speed and power in healthy men and women. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Athletes Rated as Poor Single-Leg Squat Performers Display Measureable Differences in Single-Leg Squat Biomechanics Compared to Good Performers.

    Science.gov (United States)

    Garrick, Lachlan E; Alexander, Bryce C; Schache, Anthony G; Pandy, Marcus G; Crossley, Kay M; Collins, Natalie J

    2017-11-15

    It is important to validate single-leg squat visual rating criteria used in clinical practice and research. Foot orthoses may improve single-leg squat performance in those who demonstrate biomechanics associated with increased risk of lower-limb injury. Validate visual rating criteria proposed by Crossley et al, by determining whether athletes rated as poor single-leg squat performers display different single-leg squat biomechanics than good performers; and evaluate immediate effects of foot orthoses on single-leg squat biomechanics in poor performers. Comparative cross-sectional study. University laboratory. 79 asymptomatic athletes underwent video classification of single-leg squat performance based on established visual rating criteria (overall impression, trunk posture, pelvis 'in space', hip movement, knee movement), and were rated as good (n=23), fair (n=41) or poor (n=15) performers. A subset of good (n=16) and poor (n=12) performers underwent biomechanical assessment, completing five continuous single-leg squats on their dominant limb while three-dimensional motion analysis and ground reaction force data were recorded. Poor performers repeated the task standing on prefabricated foot orthoses. Peak external knee adduction moment (KAM) and peak angles for the trunk, hip, knee and ankle. Compared to good performers, poor performers had a significantly lower peak KAM (mean difference 0.11 Nm/kg, 95% confidence interval [CI] 0.02 to 0.2 Nm/kg), higher peak hip adduction angle (-4.3°, -7.6° to -0.9°), and higher peak trunk axial rotation towards their stance limb (3.8°, 0.4° to 7.2°). Foot orthoses significantly increased the peak KAM in poor performers (-0.06 Nm/kg, -0.1 to -0.01 Nm/kg), with values approximating those observed in good performers. Findings validate Crossley et al's visual rating criteria for single-leg squat performance in asymptomatic athletes, and suggest that 'off-the-shelf' foot orthoses may be a simple intervention for poor performers

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

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    Cara L Lewis

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

  9. Trajectory of self-reported pain and function and knee extensor muscle strength in young patients undergoing arthroscopic surgery for meniscal tears

    DEFF Research Database (Denmark)

    Thorlund, Jonas Bloch; Østengaard, Lasse; Cardy, Nathan

    2017-01-01

    . PATIENTS AND INTERVENTION: People aged 30 years or younger undergoing surgery for a meniscal tear. OUTCOMES: and comparator: (1) Self-reported pain and function in patients undergoing meniscal surgery compared to a non-operative control group (2). Knee extensor strength in the leg undergoing surgery......OBJECTIVES: To investigate the trajectory of patient reported pain and function and knee extensor muscle strength over time in young individuals undergoing arthroscopic meniscal surgery. DESIGN: Systematic review and meta-analysis METHODS: Six databases were searched up to October 13th, 2016...... compared to a healthy control group or the contra-lateral leg. Methodological quality was assessed using the SIGN 50 guidelines. RESULTS: No studies were found on patient reported pain and function. Six studies, including 137 patients were included in the analysis on knee extensor muscle strength. Knee...

  10. Isokinetic Performance of Knee Flexor and Extensor Muscles in American Football Players from Brazil

    Directory of Open Access Journals (Sweden)

    Lucas Severo-Silveira

    2017-11-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2017v19n4p426   The isokinetic performance of thigh muscles has been related to athletic performance and risk for non-contact injuries, such as anterior cruciate ligament ruptures and hamstring strains. Although isokinetic profile of American football players from United States (USA is widely described, there is a lack of studies comprising players acting outside the USA. The primary objective of this study was to describe the isokinetic performance of thigh muscles in elite American football players in Brazil. Secondarily, we aimed to compare the playing positions and compare the Brazilian players with high-level athletes from USA. Knee extensor (KE and flexor (KF muscles of 72 Brazilian players were assessed through isokinetic tests at 60°·s-1. KE concentric peak torque was 276±56 N·m, while KF had concentric and eccentric peak torques of 151±37 N·m and 220±40 N·m, respectively. Offensive linemen players presented greater peak torque values than defensive lineman, halfbacks, and wide receivers (all comparisons are provided in the article. Brazilian players had lower scores than USA athletes for KE and KF peak torque values. In addition, a conventional torque ratio (concentric/concentric lower than 0.6 was found in 76-83% of athletes, and a functional ratio (eccentric/eccentric below to 1.0 in 94%. Bilateral asymmetry greater than 10% was verified in 26% and 43% of athletes for KE and KF muscles, respectively. Elite players in Brazil present high incidence of strength imbalance in thigh muscles, and they are below USA players in relation to torque production capacity of KE and KF muscles.

  11. The effects of isometric resistance training on stretch reflex induced tremor in the knee extensor muscles.

    Science.gov (United States)

    Durbaba, Rade; Cassidy, Angela; Budini, Francesco; Macaluso, Andrea

    2013-06-15

    This study examines the effect of 4 wk of high-intensity isometric resistance training on induced tremor in knee extensor muscles. Fourteen healthy volunteers were assigned to either the training group (n = 7) or the nontraining control group (n = 7). Induced tremor was assessed by measuring force fluctuations during anisometric contractions against spring loading, whose compliance was varied to allow for preferential activation of the short or long latency stretch reflex components. Effects of high-intensity isometric resistance training on induced tremor was assessed under two contraction conditions: relative force matching, where the relative level of activity was equal for both pre- and post-training sessions, set at 30% maximum voluntary contraction (MVC), and absolute force matching, where the level of activity was set to 30% pretrained MVC. The training group experienced a 26.5% increase in MVC in contrast to the 0.8% for the control group. For relative force-matching contractions, induced tremor amplitude and frequency did not change in either the training or control group. During absolute force-matching contractions, induced tremor amplitude was decreased by 37.5% and 31.6% for the short and long components, respectively, with no accompanying change in frequency, for the training group. No change in either measure was observed in the control group for absolute force-matching contractions. The results are consistent with high-intensity isometric resistance training induced neural changes leading to increased strength, coupled with realignment of stretch reflex automatic gain compensation to the new maximal force output. Also, previous reported reductions in anisometric tremor following strength training may partly be due to changed stretch reflex behavior.

  12. Intersession reliability of the interpolated twitch technique applied during isometric, concentric, and eccentric actions of the human knee extensor muscles.

    Science.gov (United States)

    Behrens, Martin; Husmann, Florian; Gube, Martin; Felser, Sabine; Weippert, Matthias; Bruhn, Sven; Zschorlich, Volker; Mau-Moeller, Anett

    2017-08-01

    Although it has been shown that voluntary activation (%VA) of the knee extensors during isometric contractions can be reliably assessed with the interpolated twitch technique, little is known about the reliability of %VA during concentric and eccentric muscle actions. Therefore, relative and absolute intersession reliability of quadriceps muscle's %VA during different contraction modes was determined. After a familiarization session, 21 participants (17 males, 25 ± 2 yrs) completed two testing sessions. Paired supramaximal electrical stimuli were administered to the femoral nerve during isometric, concentric, eccentric MVCs, and at rest to assess %VA (stimuli were applied at 70° knee flexion). Data indicate that %VA of the knee extensors can be reliably measured during isometric [intraclass correlation coefficient (ICC) = 0.89, coefficient of variation (CV) = 4.1%], concentric (ICC = 0.87, CV = 6.6%), and eccentric muscle actions (ICC = 0.86, CV = 7.0%). Muscle Nerve 56: 324-327, 2017. © 2016 Wiley Periodicals, Inc.

  13. The Association Between Knee Extensor Force Steadiness, Force Accuracy, and Mobility in Older Adults Who Have Fallen.

    Science.gov (United States)

    Chung-Hoon, Kaiwi; Tracy, Brian L; Dibble, Leland E; Marcus, Robin L; Burgess, Paul; LaStayo, Paul C

    2016-01-01

    Older adults often experience limited mobility, lower extremity muscle weakness, and increased fall risk. Furthermore, when older adults perform tasks that require control of submaximal force, impairments in their ability to maintain steady and accurate force output have been reported. Such problems may be related to deteriorating levels of mobility, particularly in older adults who have fallen. The purpose of this study was to determine whether an association exists between muscle force steadiness (MFS) or muscle force accuracy (MFA) of the knee extensors and mobility in older adults who have fallen. Twenty older adults ((Equation is included in full-text article.)= 77.5 ± 7 years, 5 males and 15 females) with 2 or more comorbid conditions and who experienced a fall in the past year underwent assessment of maximal voluntary isometric contraction of the knee extensors. A submaximal target force of 50% of their maximal voluntary isometric contraction was used to determine concentric and eccentric (ECC) steadiness (the fluctuations in force production) and accuracy (the average distance of the mean force from the target force) measures. Mobility was indicated by the 6-minute walk test, the Timed Up and Go, stair ascent, and stair descent tests. Correlation analysis was used to assess the relationship between measures of muscle force control and mobility. The correlations between muscle force steadiness and mobility were not significant (P > .05) for either contraction type. However, MFA during ECC contractions only was correlated significantly with all measures of mobility-6 minute walk test (r = -0.48; P = .03), Timed Up and Go (r = 0.68; P = .01), stair ascent (r = 0.60; P = .01), and stair descent (r = 0.75; P fallen is novel. Although the correlations are not causal, these relationships suggest that inaccurate force output during ECC contractions of the knee extensors is linked to impaired mobility.

  14. THE EFFICACY OF ANGLE-MATCHED ISOKINETIC KNEE FLEXOR AND EXTENSOR STRENGTH PARAMETERS IN PREDICTING AGILITY TEST PERFORMANCE.

    Science.gov (United States)

    Greig, Matt; Naylor, James

    2017-10-01

    Agility is a fundamental performance element in many sports, but poses a high risk of injury. Hierarchical modelling has shown that eccentric hamstring strength is the primary determinant of agility performance. The purpose of this study was to investigate the relationship between knee flexor and extensor strength parameters and a battery of agility tests. Controlled laboratory study. Nineteen recreational intermittent games players completed an agility battery and isokinetic testing of the eccentric knee flexors (eccH) and concentric knee extensors (conQ) at 60, 180 and 300°·s -1 . Peak torque and the angle at which peak torque occurred were calculated for eccH and conQ at each speed. Dynamic control ratios (eccH:conQ) and fast:slow ratios (300:60) were calculated using peak torque values, and again using angle-matched data, for eccH and conQ. The agility test battery differentiated linear vs directional changes and prescriptive vs reactive tasks. Linear regression showed that eccH parameters were generally a better predictor of agility performance than conQ parameters. Stepwise regression showed that only angle-matched strength ratios contributed to the prediction of each agility test. Trdaitionally calculated strength ratios using peak torque values failed to predict performance. Angle-matched strength parameters were able to account for 80% of the variation in T-test performance, 70% of deceleration distance, 55% of 10m sprint performance, and 44% of reactive change of direction speed. Traditionally calculated strength ratios failed to predict agility performance, whereas angle-matched strength ratios had better predictive ability and featured in a predictive stepwise model for each agility task. 2c.

  15. The Effects of High-Intensity versus Low-Intensity Resistance Training on Leg Extensor Power and Recovery of Knee Function after ACL-Reconstruction

    DEFF Research Database (Denmark)

    Bieler, Theresa; Sobol, Nanna Aue; Andersen, Lars L

    2014-01-01

    OBJECTIVE: Persistent weakness is a common problem after anterior cruciate ligament- (ACL-) reconstruction. This study investigated the effects of high-intensity (HRT) versus low-intensity (LRT) resistance training on leg extensor power and recovery of knee function after ACL-reconstruction. METH...

  16. Relation of selective voluntary motor control of the lower extremity and extensor strength of the knee joint in children with spastic diplegia.

    Science.gov (United States)

    Kusumoto, Yasuaki; Takaki, Kenji; Matsuda, Tadamitsu; Nitta, Osamu

    2016-06-01

    [Purpose] The aim of this study was to investigate differences in selective voluntary motor control of the lower extremities by objective assessment and determine the relationship between selective voluntary motor control and knee extensor strength in children with spastic diplegia. [Subjects and Methods] Forty individuals who had spastic cerebral palsy, with Gross Motor Function Classification System levels ranging from I to III, were assessed using the Selective Control Assessment of the Lower Extremity and by testing the maximum knee extensor strength. The unaffected side was defined as the lower limb with the higher score, and the affected side was defined as the lower limb with the lower score. [Results] The Selective Control Assessment of the Lower Extremity score on the affected side had a lower average than that on the unaffected side. The scores showed a significant inverse correlation with the maximum knee extensor strength. [Conclusion] There was bilateral difference in the selective voluntary motor control of the lower extremities in children with spastic diplegia, and the selective voluntary motor control of the lower extremity was related to maximum knee extensor strength.

  17. Leg extensor muscle strength, postural stability, and fear of falling after a 2-month home exercise program in women with severe knee joint osteoarthritis.

    Science.gov (United States)

    Rätsepsoo, Monika; Gapeyeva, Helena; Sokk, Jelena; Ereline, Jaan; Haviko, Tiit; Pääsuke, Mati

    2013-01-01

    BACKGROUND AND OBJECTIVE. The aim of this study was to compare the leg extensor muscle strength, the postural stability, and the fear of falling in the women with severe knee joint osteoarthritis (OA) before and after a 2-month home exercise program (HEP). MATERIAL AND METHODS. In total, 17 women aged 46-72 years with late-stage knee joint OA scheduled for total knee arthroplasty participated in this study before and after the 2-month HEP with strengthening, stretching, balance, and step exercises. The isometric peak torque (PT) of the leg extensors and postural stability characteristics when standing on a firm or a foam surface for 30 seconds were recorded. The fear of falling and the pain intensity (VAS) were estimated. RESULTS. A significant increase in the PT and the PT-to-body weight (PT-to-BW) ratio of the involved leg as well as the bilateral PT and the PT-to-BW ratio was found after the 2-month HEP compared with the data before the HEP (Pafter the HEP (PAfter the 2-month HEP, the leg extensor muscle strength increased and the postural sway length on a foam surface decreased. The results indicate that the increased leg extensor muscle strength improves postural stability and diminishes the fear of falling in women with late-stage knee joint OA.

  18. Magnitude of force perception errors during static contractions of the knee extensors in healthy young and elderly individuals.

    Science.gov (United States)

    Lauzière, Séléna; Dubois, Benjamin; Brière, Anabèle; Nadeau, Sylvie

    2012-01-01

    The accuracy of force perception during muscular contraction has not been studied extensively, despite its importance in rehabilitation and training. The purpose of this study was to quantify the errors made by healthy young and elderly individuals in their perceptions of force produced at the knee. Four different tasks were used to evaluate the perception of force and the effect of a sensory-motor reference and simultaneous contraction on the accuracy of perception. The absolute errors were similar between groups, with values of 11.9% to 16.3%, depending on the task. The raw perception errors were greater for high levels of force (>50% of the maximal voluntary contraction, or MVC), indicating an overestimation of the forces produced for both groups. At 70% MVC, the sensory-motor reference reduced raw perception errors, and the simultaneous contraction improved the accuracy of force production. Healthy young and elderly individuals had about the same capacity to judge the muscular force of their knee extensors. Therapists involved in the training of active elderly individuals should be aware that the accuracy of force perception is not perfect and that these clients have the same ability as young individuals to perceive their knee extension strength.

  19. The effects of knee extensor eccentric training on functional tests in healthy subjects Os efeitos do treino isocinético excêntrico dos extensores do joelho nos testes funcionais em sujeitos saudáveis

    Directory of Open Access Journals (Sweden)

    Heleodório H. Santos

    2010-08-01

    Full Text Available BACKGROUND: It is well known that eccentric training increases muscle strength and promotes greater neural activation, and therefore has been used in the recovery of knee extensors. The hypothesis of this study was that there would be a strong correlation between knee extensor torque and functional tests. OBJECTIVES: To investigate the relationship between knee extensor peak torque and functional tests of agility (runs and propulsion (hop for distance after short-term isokinetic eccentric training. METHODS: Twenty healthy and active male undergraduate students (age 22.5±2.1 years; height 1.72±0.10 m; weight 67.8±9.5 kg; body mass index: 22.5±2.0 kg/m², with no abnormalities or history of injury of the limbs, performed an isokinetic assessment of the knee extensors and flexors and also functional tests before and after isokinetic training, which consisted of 3 sets of 10 MVECs at 30º/s, with 3 minutes of rest between sets, twice a week for 6 weeks. RESULTS: The eccentric training increased the extensor peak torque (16, 27 and 17%; PCONTEXTUALIZAÇÃO: Sabe-se que o treino excêntrico aumenta a força muscular, promovendo uma maior ativação neural e, portanto, tem sido usado na recuperação do torque extensor. A hipótese deste estudo foi a de que possa existir uma forte correlação entre o torque extensor do joelho e os testes funcionais. OBJETIVOS: Correlacionar o torque extensor do joelho com os testes funcionais de agilidade (corridas e impulsão (saltos em distância após o treino isocinético excêntrico de curta duração. MÉTODOS: Vinte homens universitários, ativos e saudáveis (22,5±2,1 anos; 1,72±0,10 m; 67,8±9,5 kg; IMC 22,5±2,0 kg/m², sem reportar anormalidades ou história de lesão no membro inferior, realizaram avaliação isocinética do torque extensor e flexor do joelho e testes funcionais antes e depois do treino isocinético que consistiu em três séries de 10 CEVM a 30º/s, com 3 minutos de repouso entre as

  20. Inter- and intrarater reliability of the Modified Modified Ashworth Scale in patients with knee extensor poststroke spasticity.

    Science.gov (United States)

    Ansari, Noureddin Nakhostin; Naghdi, Soofia; Younesian, Parastoo; Shayeghan, Mohammad

    2008-01-01

    Muscle spasticity is a common motor disorder following upper motor neuron syndrome. A reliable and valid clinical tool is essential to document the effect of therapeutic interventions aimed to improve function by reducing spasticity. The Modified Ashworth Scale (MAS) is the most widely used and accepted clinical scale of spasticity. The MAS has been recently modified. The aim of this investigation was to determine the interrater and intrarater reliability of clinical test of knee extensor post-stroke spasticity graded on a Modified Modified Ashworth Scale (MMAS). Two raters scored the muscle spasticity of 15 patients with ischaemic stroke. For the inter- and intrarater reliability, two raters agreed on 80.1% and 86.6%, respectively. The Kappa values were good (kappa=0.72, SE=0.14, pscale.

  1. Isokinetic dynamometry of knee flexors and extensors: comparative study among non-athletes, jumper athletes and runner athletes

    Directory of Open Access Journals (Sweden)

    Siqueira Cássio Marinho

    2002-01-01

    Full Text Available Participation in intensive sports activities leads to muscular specializations that may generate alterations in involved articular forces and cause static (posture and dynamic changes (alterations of articular stability, coordination, etc.. Prevention of injury requires specific functional muscular evaluation in all athletes and for any kind of sport. OBJECTIVE: To dynamically evaluate, through isokinetic tests, the peak torque, total work, and average power of the knee flexor and extensor muscles of jumper and runner athletes and compare them to those of a non-athletic population, evaluating dominance and balance between agonistic and antagonistic muscle groups. RESULTS: In the non-athlete group, we noted a higher asymmetry between the dominant and nondominant members. The jumpers had the highest values of the evaluated parameters of all groups, whereas parameters for the runners were intermediate between non-athletes and jumpers.

  2. Influence of acetaminophen and ibuprofen on in vivo patellar tendon adaptations to knee extensor resistance exercise in older adults

    DEFF Research Database (Denmark)

    Carroll, Chad C; Dickinson, Jared M; Lemoine, Jennifer K

    2011-01-01

    Millions of older individuals consume acetaminophen or ibuprofen daily and these same individuals are encouraged to participate in resistance training. Several in vitro studies suggest that cyclooxygenase-inhibiting drugs can alter tendon metabolism and may influence adaptations to resistance...... training. Thirty-six individuals were randomly assigned to a Placebo (67±2y), Acetaminophen (64±1y; 4000mg(.)d(-1)), or Ibuprofen (64±1y; 1200mg(.)d(-1)) group in a double-blind manner and completed 12-weeks of knee extensor resistance-training. Before and after training in vivo patellar tendon properties......, and this response was not influenced with ibuprofen consumption. Mean tendon CSA increased with training in the Acetaminophen group (3%, p0.05) with training in the Placebo group. These responses were generally uninfluenced by ibuprofen consumption. In the Acetaminophen group, tendon deformation and strain...

  3. Influence of acetaminophen and ibuprofen on in vivo patellar tendon adaptations to knee extensor resistance exercise in older adults

    DEFF Research Database (Denmark)

    Carroll, C C; Dickinson, J M; LeMoine, J K

    2011-01-01

    Millions of older individuals consume acetaminophen or ibuprofen daily and these same individuals are encouraged to participate in resistance training. Several in vitro studies suggest that cyclooxygenase-inhibiting drugs can alter tendon metabolism and may influence adaptations to resistance...... training. Thirty-six individuals were randomly assigned to a placebo (67 ± 2 yr old), acetaminophen (64 ± 1 yr old; 4,000 mg/day), or ibuprofen (64 ± 1 yr old; 1,200 mg/day) group in a double-blind manner and completed 12 wk of knee extensor resistance training. Before and after training in vivo patellar...... group, and this response was not influenced with ibuprofen consumption. Mean tendon CSA increased with training in the acetaminophen group (3%, P

  4. Central and peripheral fatigue in knee and elbow extensor muscles after a long-distance cross-country ski race.

    Science.gov (United States)

    Boccia, G; Dardanello, D; Zoppirolli, C; Bortolan, L; Cescon, C; Schneebeli, A; Vernillo, G; Schena, F; Rainoldi, A; Pellegrini, B

    2017-09-01

    Although elbow extensors (EE) have a great role in cross-country skiing (XC) propulsion, previous studies on neuromuscular fatigue in long-distance XC have investigated only knee extensor (KE) muscles. In order to investigate the origin and effects of fatigue induced by long-distance XC race, 16 well-trained XC skiers were tested before and after a 56-km classical technique race. Maximal voluntary isometric contraction (MVC) and rate of force development (RFD) were measured for both KE and EE. Furthermore, electrically evoked double twitch during MVC and at rest were measured. MVC decreased more in KE (-13%) than in EE (-6%, P = 0.016), whereas the peak RFD decreased only in EE (-26%, P = 0.02) but not in KE. The two muscles showed similar decrease in voluntary activation (KE -5.0%, EE -4.8%, P = 0.61) and of double twitch amplitude (KE -5%, EE -6%, P = 0.44). A long-distance XC race differently affected the neuromuscular function of lower and upper limbs muscles. Specifically, although the strength loss was greater for lower limbs, the capacity to produce force in short time was more affected in the upper limbs. Nevertheless, both KE and EE showed central and peripheral fatigue, suggesting that the origins of the strength impairments were multifactorial for the two muscles. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Improved knee extensor strength with resistance training associates with muscle specific miRNAs in older adults.

    Science.gov (United States)

    Zhang, Tan; Birbrair, Alexander; Wang, Zhong-Min; Messi, María L; Marsh, Anthony P; Leng, Iris; Nicklas, Barbara J; Delbono, Osvaldo

    2015-02-01

    Regular exercise, particularly resistance training (RT), is the only therapy known to consistently improve muscle strength and quality (force per unit of mass) in older persons, but there is considerable variability in responsiveness to training. Identifying sensitive diagnostic biomarkers of responsiveness to RT may inform the design of a more efficient exercise regimen to improve muscle strength in older adults. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression. We quantified six muscle specific miRNAs (miR-1, -133a, -133b, -206, -208b and -499) in both muscle tissue and blood plasma, and their relationship with knee extensor strength in seven older (age=70.5 ± 2.5 years) adults before and after 5 months of RT. MiRNAs differentially responded to RT; muscle miR-133b decreased, while all plasma miRNAs tended to increase. Percent changes in knee extensor strength with RT showed strong positive correlations with percent changes in muscle miR-133a, -133b, and -206 and with percent changes in plasma and plasma/muscle miR-499 ratio. Baseline level of plasma or plasma/muscle miR-499 ratio further predicts muscle response to RT, while changes in muscle miR-133a, -133b, and -206 may correlate with muscle TNNT1 gene alternative splicing in response to RT. Our results indicate that RT alters muscle specific miRNAs in muscle and plasma, and that these changes account for some of the variation in strength responses to RT in older adults. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Modulation of frontal-plane knee kinematics by hip-extensor strength and gluteus maximus recruitment during a jump-landing task in healthy women.

    Science.gov (United States)

    Hollman, John H; Hohl, Jeffrey M; Kraft, Jordan L; Strauss, Jeffrey D; Traver, Katie J

    2013-08-01

    Abnormal lower extremity kinematics during dynamic activities may be influenced by impaired gluteus maximus function. To examine whether hip-extensor strength and gluteus maximus recruitment are associated with dynamic frontal-plane knee motion during a jump-landing task. Exploratory study. Biomechanics laboratory. 40 healthy female volunteers. Isometric hip-extension strength was measured bilaterally with a handheld dynamometer. Three-dimensional hip and knee kinematics and gluteus maximus electromyography data were collected bilaterally during a jump-landing test. Data were analyzed with hierarchical linear regression and partial correlation coefficients (α = .05). Hip motion in the transverse plane was highly correlated with knee motion in the frontal plane (partial r = .724). After controlling for hip motion, reduced magnitudes of isometric hip-extensor strength (partial r = .470) and peak gluteus maximus recruitment (partial r = .277) were correlated with increased magnitudes of knee valgus during the jump-landing task. Hip-extensor strength and gluteus maximus recruitment, which represents a measure of the muscle's neuromuscular control, are both associated with frontal-plane knee motions during a dynamic weight-bearing task.

  7. Enhancing the examiner's resisting force improves the validity of manual muscle strength measurements: application to knee extensors and flexors.

    Science.gov (United States)

    Lu, Tung-Wu; Chien, Hui-Lien; Chang, Ling-Ying; Hsu, Horng-Chaung

    2012-09-01

    The purposes of this study were to test whether an examiner's strength may affect the validity of the knee muscle strength measurements using a hand-held dynamometer (HHD) and whether enhancing the forces applied by an examiner using a resistance-enhanced dynamometer (RED) would improve measurement validity. Twenty-five young male volunteers (mean [±SD] age: 22.5 ± 1.7 years) without a history of injury to the test limb and 6 male and 6 female experienced examiners participated in this study. Maximum resisting forces of the knee flexors and extensors were measured using RED, HHD, and a dynamometer (Kin-Com). For all testing conditions, poor to moderate associations were found between the HHD and Kin-Com, whereas there was a good to excellent relationship between RED and Kin-Com. The systematic variations between RED and Kin-Com were also smaller than those between HHD and Kin-Com. The force values measured by RED were very close to those measured by Kin-Com. An examiner's strength affects the validity of the measurements using HHD. Enhancing the forces applied by the examiner to the tested segment using RED appeared to improve the validity of muscle strength measurements.

  8. Examination of Knee Isokinetic Strength and Single-Leg Balance of Operated and Non-Operated Side of Patients with Unilateral Matrix-Induced Autologous Chondrocyte Implantation (MACI Surgery : Pilot Study

    Directory of Open Access Journals (Sweden)

    Çağlar Soylu

    2017-09-01

    Conclusion: It was determined that the operated side's hamstring/quadriceps ratio after MACI surgery was weaker than the normal value, against the quadriceps, and for quadriceps muscle strength of both sides, there was a difference higher than 10%, which is considered to be the normal limit. This reveals that home programs may be insufficient for people who have undergone MACI surgery, and also that muscular strength of people should be followed up in the long term. Therefore, we think that special rehabilitation protocols as the ones that exist in other knee cartilage operations should be applied following MACI surgery.

  9. Assessment of muscular strength of knee flexors and extensors in individuals with and without osteoarthritis

    Directory of Open Access Journals (Sweden)

    Sebastião Iberes Lopes Melo

    2008-01-01

    The aim of this study was to evaluate concentric and eccentric torque in individuals with and without knee osteoarthritis, and who did and did not practice physical activity. Specifically: to compare concentric and eccentric torque between groups; to compare the torques of dominant and non-dominant limbs within groups; to compare the concentric hamstrings/quadriceps ratio between groups. Fifty-eight elderly people participated, 32 with knee osteoarthritis and 26 with healthy knees. An isokinetic KinCom dynamometer was used for data collection. Concentric and eccentric peak torques of the quadriceps and hamstrings, normalized for body weight and concentric peak torque hamstring/quadriceps ratio of both sides were the study variables. At the Biomechanics Laboratory the following procedures were carried out: 1 identification form; 2 anthropometry; 3 warm-up and stretching; 4 positioning of the individual in a seated position with knee flexion of 90º and the back supported; 5 familiarization with the equipment; 6 acquisition of three reciprocal maximal concentric and eccentric contractions at 60º/s. Descriptive statistics and the Wilcoxon and the U Mann-Whitney tests were used to analyze data, to p≤0.05. The majority of concentric and eccentric torques in the control group were higher than those in the knee osteoarthritis group, with the exception of the concentric torque of non-dominant hamstrings and the eccentric quadriceps of the non-dominant limb. Although not significant, dominance seems to be determinant of increased torques in individuals without knee osteoarthritis. No statistically significant differences were detected between those who did and those who did not take part in physical activity. The results demonstrate that osteoarthritis provokes decrease of force especially in quadriceps.

  10. Assessment of muscular strength of knee flexors and extensors in individuals with and without osteoarthritis

    Directory of Open Access Journals (Sweden)

    Sebastião Iberes Lopes Melo

    2008-12-01

    Full Text Available The aim of this study was to evaluate concentric and eccentric torque in individuals with and without knee osteoarthritis, and who did and did not practice physical activity. Specifically: to compare concentric and eccentric torque between groups; to compare the torques of dominant and non-dominant limbs within groups; to compare the concentric hamstrings/quadriceps ratio between groups. Fifty-eight elderly people participated, 32 with knee osteoarthritis and 26 with healthy knees. An isokinetic KinCom dynamometer was used for data collection. Concentric and eccentric peak torques of the quadriceps and hamstrings, normalized for body weight and concentric peak torque hamstring/quadriceps ratio of both sides were the study variables. At the Biomechanics Laboratory the following procedures were carried out: 1 identification form; 2 anthropometry; 3 warm-up and stretching; 4 positioning of the individual in a seated position with knee flexion of 90º and the back supported; 5 familiarization with the equipment; 6 acquisition of three reciprocal maximal concentric and eccentric contractions at 60º/s. Descriptive statistics and the Wilcoxon and the U Mann-Whitney tests were used to analyze data, to p≤0.05. The majority of concentric and eccentric torques in the control group were higher than those in the knee osteoarthritis group, with the exception of the concentric torque of non-dominant hamstrings and the eccentric quadriceps ofthe non-dominant limb. Although not significant, dominance seems to be determinant of increased torques in individuals withoutknee osteoarthritis. No statistically significant differences were detected between those who did and those who did not take part in physical activity. The results demonstrate that osteoarthritis provokes decrease of force especially in quadriceps.

  11. The wrinkled patellar tendon: An indication of abnormality in the extensor mechanism of the knee

    International Nuclear Information System (INIS)

    Berlin, R.C.; Levinsohn, E.M.; Chrisman, H.

    1991-01-01

    Rupture of the quadriceps tendon is an uncommon condition which requires early diagnosis and treatment to avert prolonged disability. In four patients who had surgically confirmed quadriceps tendon rupture, lateral radiographs of the knee and/or sagittal magnetic resonance (MR) images demonstrated a corrugated appearance to the patellar tendon. Sagittal MR images of the knee following patellectomy in one patient and radiographs of a transverse fracture of the patella in another also demonstrated this appearance. MRI has superb contrast resolution which provides optimal visualization of the contour of the patellar tendon on sagittal images. A retrospective review of 50 consecutive knee MRI examinations was carried out to evaluate the appearance of the normal patellar tendon. In 49 of 50 patients, the sagittal images demonstrated a straight or nearly straight patellar tendon. A corrugated appearance of the patellar tendon on sagittal images indicates a reduction in the normal tensile force applied to it and indicates the need for careful evaluation of the patella and quadriceps tendon mechanism. (orig.)

  12. Superior Effects of Eccentric to Concentric Knee Extensor Resistance Training on Physical Fitness, Insulin Sensitivity and Lipid Profiles of Elderly Men.

    Science.gov (United States)

    Chen, Trevor Chung-Ching; Tseng, Wei-Chin; Huang, Guan-Ling; Chen, Hsin-Lian; Tseng, Kuo-Wei; Nosaka, Kazunori

    2017-01-01

    It has been reported that eccentric training of knee extensors is effective for improving blood insulin sensitivity and lipid profiles to a greater extent than concentric training in young women. However, it is not known whether this is also the case for elderly individuals. Thus, the present study tested the hypothesis that eccentric training of the knee extensors would improve physical function and health parameters (e.g., blood lipid profiles) of older adults better than concentric training. Healthy elderly men (60-76 years) were assigned to either eccentric training or concentric training group ( n = 13/group), and performed 30-60 eccentric or concentric contractions of knee extensors once a week. The intensity was progressively increased over 12 weeks from 10 to 100% of maximal concentric strength for eccentric training and from 50 to 100% for concentric training. Outcome measures were taken before and 4 days after the training period. The results showed that no sings of muscle damage were observed after any sessions. Functional physical fitness (e.g., 30-s chair stand) and maximal concentric contraction strength of the knee extensors increased greater ( P ≤ 0.05) after eccentric training than concentric training. Homeostasis model assessment, oral glucose tolerance test and whole blood glycosylated hemoglobin showed improvement of insulin sensitivity only after eccentric training ( P ≤ 0.05). Greater ( P ≤ 0.05) decreases in fasting triacylglycerols, total, and low-density lipoprotein cholesterols were evident after eccentric training than concentric training, and high-density lipoprotein cholesterols increased only after eccentric training. These results support the hypothesis and suggest that it is better to focus on eccentric contractions in exercise medicine.

  13. Superior Effects of Eccentric to Concentric Knee Extensor Resistance Training on Physical Fitness, Insulin Sensitivity and Lipid Profiles of Elderly Men

    Science.gov (United States)

    Chen, Trevor Chung-Ching; Tseng, Wei-Chin; Huang, Guan-Ling; Chen, Hsin-Lian; Tseng, Kuo-Wei; Nosaka, Kazunori

    2017-01-01

    It has been reported that eccentric training of knee extensors is effective for improving blood insulin sensitivity and lipid profiles to a greater extent than concentric training in young women. However, it is not known whether this is also the case for elderly individuals. Thus, the present study tested the hypothesis that eccentric training of the knee extensors would improve physical function and health parameters (e.g., blood lipid profiles) of older adults better than concentric training. Healthy elderly men (60–76 years) were assigned to either eccentric training or concentric training group (n = 13/group), and performed 30–60 eccentric or concentric contractions of knee extensors once a week. The intensity was progressively increased over 12 weeks from 10 to 100% of maximal concentric strength for eccentric training and from 50 to 100% for concentric training. Outcome measures were taken before and 4 days after the training period. The results showed that no sings of muscle damage were observed after any sessions. Functional physical fitness (e.g., 30-s chair stand) and maximal concentric contraction strength of the knee extensors increased greater (P ≤ 0.05) after eccentric training than concentric training. Homeostasis model assessment, oral glucose tolerance test and whole blood glycosylated hemoglobin showed improvement of insulin sensitivity only after eccentric training (P ≤ 0.05). Greater (P ≤ 0.05) decreases in fasting triacylglycerols, total, and low-density lipoprotein cholesterols were evident after eccentric training than concentric training, and high-density lipoprotein cholesterols increased only after eccentric training. These results support the hypothesis and suggest that it is better to focus on eccentric contractions in exercise medicine. PMID:28443029

  14. Loss of knee extensor torque complexity during fatiguing isometric muscle contractions occurs exclusively above the critical torque.

    Science.gov (United States)

    Pethick, Jamie; Winter, Samantha L; Burnley, Mark

    2016-06-01

    The complexity of knee extensor torque time series decreases during fatiguing isometric muscle contractions. We hypothesized that because of peripheral fatigue, this loss of torque complexity would occur exclusively during contractions above the critical torque (CT). Nine healthy participants performed isometric knee extension exercise (6 s of contraction, 4 s of rest) on six occasions for 30 min or to task failure, whichever occurred sooner. Four trials were performed above CT (trials S1-S4, S1 being the lowest intensity), and two were performed below CT (at 50% and 90% of CT). Global, central, and peripheral fatigue were quantified using maximal voluntary contractions (MVCs) with femoral nerve stimulation. The complexity of torque output was determined using approximate entropy (ApEn) and the detrended fluctuation analysis-α scaling exponent (DFA-α). The MVC torque was reduced in trials below CT [by 19 ± 4% (means ± SE) in 90%CT], but complexity did not decrease [ApEn for 90%CT: from 0.82 ± 0.03 to 0.75 ± 0.06, 95% paired-samples confidence intervals (CIs), 95% CI = -0.23, 0.10; DFA-α from 1.36 ± 0.01 to 1.32 ± 0.03, 95% CI -0.12, 0.04]. Above CT, substantial reductions in MVC torque occurred (of 49 ± 8% in S1), and torque complexity was reduced (ApEn for S1: from 0.67 ± 0.06 to 0.14 ± 0.01, 95% CI = -0.72, -0.33; DFA-α from 1.38 ± 0.03 to 1.58 ± 0.01, 95% CI 0.12, 0.29). Thus, in these experiments, the fatigue-induced loss of torque complexity occurred exclusively during contractions performed above the CT. Copyright © 2016 the American Physiological Society.

  15. Isometric knee extensor fatigue following a Wingate test: peripheral and central mechanisms.

    Science.gov (United States)

    Fernandez-del-Olmo, M; Rodriguez, F A; Marquez, G; Iglesias, X; Marina, M; Benitez, A; Vallejo, L; Acero, R M

    2013-02-01

    Central and peripheral fatigue have been explored during and after running or cycling exercises. However, the fatigue mechanisms associated with a short maximal cycling exercise (30 s Wingate test) have not been investigated. In this study, 10 volunteer subjects performed several isometric voluntary contractions using the leg muscle extensors before and after two bouts of cycling at 25% of maximal power output and two bouts of Wingate tests. Transcranial magnetic stimulation (TMS) and electrical motor nerve stimulation (NM) were applied at rest and during the voluntary contractions. Maximal voluntary contraction (MVC), voluntary activation (VA), twitch amplitude evoked by electrical nerve stimulation, M wave and motor potential evoked by TMS (MEP) were recorded. MVC, VA and twitch amplitude evoked at rest by NM decreased significantly after the first and second Wingate tests, indicating central and peripheral fatigue. MVC and VA, but not the twitch amplitude evoked by NM, recovered before the second Wingate test. These results suggest that the Wingate test results in a decrease in MVC associated with peripheral and central fatigue. While the peripheral fatigue is associated with an intramuscular impairment, the central fatigue seems to be the main reason for the Wingate test-induced impairment of MVC. © 2011 John Wiley & Sons A/S.

  16. Efeitos do Tai Chi Chuan na força dos músculos extensores dos joelhos e no equilíbrio em idosas Effects of Tai Chi Chuan on knee extensor muscle strength and balance in elderly women

    Directory of Open Access Journals (Sweden)

    MM Pereira

    2008-04-01

    Full Text Available CONTEXTUALIZAÇÃO: Alguns estudos têm indicado que o Tai Chi Chuan (TCC é capaz de melhorar o condicionamento físico, a força muscular e o equilíbrio entre os praticantes idosos, prevenindo quedas, fraturas e dependência física. OBJETIVO: Verificar os efeitos do TCC no equilíbrio (EQ e na força dos músculos extensores dos joelhos (F em mulheres idosas. MATERIAIS E MÉTODOS: Participaram do estudo 77 mulheres saudáveis, não praticantes de atividade física orientada. No Grupo Experimental (G1 foram incluídas 38 voluntárias (68 ± 5 anos e no Grupo Controle (G2, 39 voluntárias (69 ± 7 anos. O G1 praticou o TCC estilo Yang de 24 movimentos durante 12 semanas, três vezes por semana, com duração de 50 minutos. O G2 não realizou atividades físicas orientadas. A força foi mensurada pelo teste de 1-RM na cadeira extensora e o equilíbrio foi avaliado utilizando o teste de apoio unipodal com os olhos fechados. Na análise estatística, utilizou-se teste de normalidade, split-plot análise de variância (ANOVA e correlação de Pearson. RESULTADOS: O Grupo Experimental apresentou incrementos de 17,83% na F e 26,10% no EQ. O Grupo Controle não apresentou alteração significativa em nenhuma variável. Não foi observada correlação significativa entre estas duas variáveis no G1 (r= 0,09; p= 0,554 e no G2 (r= 0,07; p= 0,660. CONCLUSÕES: Estes resultados sugerem que o TCC melhora F e EQ em mulheres idosas. Entretanto, a força dos músculos extensores dos joelhos não está necessariamente ligada ao equilíbrio nesta modalidade.BACKGROUND: Some studies have indicated that Tai Chi Chuan (TCC is capable of improving physical fitness, muscle strength and balance in elderly people. This improvement could prevent falls, fractures and physical dependence. OBJECTIVE: To investigate the effects of TCC on balance and knee extensor muscle strength among elderly women. METHODS: Seventy-seven healthy women who were not engaged in any guided

  17. Effects of isokinetic training of the knee extensors on isometric strength and peak power output during cycling.

    Science.gov (United States)

    Mannion, A F; Jakeman, P M; Willan, P L

    1992-01-01

    Isokinetic training of right and left quadriceps femoris was undertaken three times per week for 16 weeks. One group of subjects (n = 13) trained at an angular velocity of 4.19 rad.s-1 and a second group (n = 10) at 1.05 rad.s-1. A control group (n = 10) performed no training. Maximal voluntary contraction (MVC) of the quadriceps, and peak pedal velocity nu p,peak) and peak power output (Wpeak) during all-out cycling (against loads equivalent to 9, 10, 11, 12, 13 and 14% MVC) were assessed before and after training. The two training groups did not differ significantly from each other in their training response to any of the performance variables (P > 0.05). No significant difference in MVC was observed for any group after the 16-week period (P = 0.167). The post-training increases in average Wpeak (7%) and nu p,peak (6%) during the cycle tests were each significantly different from the control group response (P = 0.018 and P = 0.008, respectively). It is concluded that 16 weeks of isokinetic strength training of the knee extensors is able to significantly improve nu p, peak and Wpeak during spring cycling, an activity which demands considerable involvement of the trained muscle group but with its own distinct pattern of coordination.

  18. Speed-related spinal excitation from ankle dorsiflexors to knee extensors during human walking

    DEFF Research Database (Denmark)

    Iglesias, Caroline; Nielsen, Jens Bo; Marchand-Pauvert, Véronique

    2008-01-01

    investigated the CPQ-reflex at different walking speeds (1-6 km/h) and stride frequencies (0.6-1.3 Hz) in healthy human subjects to provide further evidence of its modulation, and its role in ensuring postural stability during walking. The CPQ-reflex was small or absent at walking speeds below 2-3 km....../h, then increased with walking speeds about 3-4 km/h, and reached a plateau without any further change at walking speeds from 4 to 6 km/h. The reflex showed no modulation when the stride cycle was varied at constant speed (4 km/h; short steps versus long steps). These changes were unlikely to be only caused...... by changes in the background EMG activity and modifications in peripheral input, and likely reflected central modulation of transmission in the involved reflex pathways as well. It is suggested that the purpose of the reflex is to ensure knee stability at moderate-to-high walking speeds....

  19. BUILDING A BETTER GLUTEAL BRIDGE: ELECTROMYOGRAPHIC ANALYSIS OF HIP MUSCLE ACTIVITY DURING MODIFIED SINGLE-LEG BRIDGES

    Science.gov (United States)

    Edwards, Michael; Haverkamp, Ryan; Martin, Lani; Porter, Kambry; Thach, Kailey; Sack, Richard J.; Hakansson, Nils A.

    2017-01-01

    Background Gluteal strength plays a role in injury prevention, normal gait patterns, eliminating pain, and enhancing athletic performance. Research shows high gluteal muscle activity during a single-leg bridge compared to other gluteal strengthening exercises; however, prior studies have primarily measured muscle activity with the active lower extremity starting in 90 ° of knee flexion with an extended contralateral knee. This standard position has caused reports of hamstring cramping, which may impede optimal gluteal strengthening. Hypothesis/Purpose The purpose of this study was to determine which modified position for the single-leg bridge is best for preferentially activating the gluteus maximus and medius. Study Design Cross-Sectional Methods Twenty-eight healthy males and females aged 18-30 years were tested in five different, randomized single-leg bridge positions. Electromyography (EMG) electrodes were placed on subjects’ gluteus maximus, gluteus medius, rectus femoris, and biceps femoris of their bridge leg (i.e., dominant or kicking leg), as well as the rectus femoris of their contralateral leg. Subjects performed a maximal voluntary isometric contraction (MVIC) for each tested muscle prior to performing five different bridge positions in randomized order. All bridge EMG data were normalized to the corresponding muscle MVIC data. Results A modified bridge position with the knee of the bridge leg flexed to 135 ° versus the traditional 90 ° of knee flexion demonstrated preferential activation of the gluteus maximus and gluteus medius compared to the traditional single-leg bridge. Hamstring activation significantly decreased (p gluteus maximus and medius, respectively). Conclusion Modifying the traditional single-leg bridge by flexing the active knee to 135 ° instead of 90 ° minimizes hamstring activity while maintaining high levels of gluteal activation, effectively building a bridge better suited for preferential gluteal activation

  20. Single-leg landing neuromechanical data following load and land height manipulations

    Directory of Open Access Journals (Sweden)

    Andrew D. Nordin

    2016-09-01

    Full Text Available Lower extremity sagittal kinematic and kinetic data are summarized alongside electrical muscle activities during single-leg landing trials completed in contrasting external load and landing height conditions. Nineteen subjects were analyzed during 9 landing trials in each of 6 experimental conditions computed as percentages of subject anthropometrics (bodyweight: BW and subject height: H; BW, BW+12.5%, BW+25%, and H12.5%, H25%. Twelve lower extremity variables (sagittal hip, knee, ankle angles and moments, vertical ground reaction force (GRFz, gluteus maximus, biceps femoris, vastus medials, medial gastrocnemius, and tibialis anterior muscles were assessed using separate principal component analyses (PCA. Variable trends across conditions were summarized in “Neuromechanical synergies in single-leg landing reveal changes in movement control. Human Movement Science” (Nordin and Dufek, 2016 [1], revealing changes in landing biomechanics and movement control.

  1. Knee extensors neuromuscular fatigue changes the corticospinal pathway excitability in biceps brachii muscle.

    Science.gov (United States)

    Aboodarda, Saied Jalal; Šambaher, Nemanja; Millet, Guillaume Y; Behm, David G

    2017-01-06

    Equivocal evidence indicates that high-intensity muscle contractions can affect the corticospinal responses in muscles not directly involved in the task. In the present study, the responsiveness of corticomotor pathway innervating non-dominant biceps brachii was measured in eleven healthy participants before and after: (i) two 100-s isometric unilateral knee extension maximal voluntary contractions (MVCs) on dominant leg (FATIGUE) and (ii) rest (CONTROL). Transcranial magnetic stimulation, transmastoid electrical and brachial plexus electrical stimulation were used to evoke motor evoked potential (MEP), cervicomedullary motor evoked potential (CMEP) and compound muscle action potential (Mmax) in biceps brachii muscle. The three stimuli were elicited at 2, 3.5 and 5s while participants were performing 6-s elbow flexion contractions at 100, 50, and 5% of MVC interspersed with 10-s rest. The results demonstrated opposing behaviors of MEP responses at 100% (23% higher, p=0.08) and 5% MVC (34% lower, p=0.019) following FATIGUE compared to CONTROL. Similarly, MEP·CMEP -1 ratio changes indicated that the supraspinal motor response was significantly higher during 100% (42%, p=0.027) but lower during 5% MVC (28%, p=0.009) following FATIGUE. Yet, the elbow flexor MVC force did not exhibit any difference between FATIGUE and CONTROL conditions. These results suggest that the upper limb muscles' corticomotor pathway responsiveness recorded during voluntary contractions were modulated by lower limbs fatiguing contractions and this modulation depends on the force produced during testing, i.e. level of central motor drive. However, these changes have little effect on upper limb muscle maximal performance. Copyright © 2016 IBRO. All rights reserved.

  2. Flexor-extensor relationship knee after reconstruction of the anterior cruciate ligament

    Directory of Open Access Journals (Sweden)

    Cristiano Ingo Dagnoni

    Full Text Available Introduction The incidence of knee injuries is very high in young adults. Anterior cruciate ligament (ACL rupture is the most frequent of them. The isokinetic dynamometry evaluation determines the functional patterns of strength and muscle balance.Objective To compare the isokinetic hamstring/quadriceps peak torque and work ratios of young adults after surgical reconstruction of the anterior cruciate ligament.Methods We selected 33 medical records filed by the Isokinetic laboratory of the Physiotherapy Clinic of the Catholic University of Paraná (PUCPR, which belonged to patients who had undergone isokinetic assessment at the request of a physiotherapist or physician in Curitiba, Paraná. The tabulated data were: Hamstring/Quadriceps peak torque and work ratios of all injured and non-injured limbs at an angular velocity of 60°/s. Data were processed by the statistical software LHstat. Inferential statistics was used in order to apply the comparison test between means (unpaired t-test with a confidence interval of 95%.Results The average flexion-extension ratio of the non-involved limb was lower than the involved limb both for peak torque (peak torque ratio of the non-involved limb: 56.1%; peak torque ratio of the involved limb: 66.3%; difference: 10.2% and work (work ratio of the non-involved limb: 60.1%; work ratio of involved limb: 66.1%; difference: 6%.Conclusion : The average flexion/extension ratio found was adequate for both limbs and variables, however, the subjects presented a greater number of muscle asymmetries in the involved limb than in the non-involved limb.

  3. Force-velocity characteristics of the knee extensors: an indication of the risk for physical frailty in elderly women.

    Science.gov (United States)

    Van Roie, Evelien; Verschueren, Sabine M; Boonen, Steven; Bogaerts, An; Kennis, Eva; Coudyzer, Walter; Delecluse, Christophe

    2011-11-01

    To examine the relationship between muscle strength, speed of movement, muscle mass (MM), and functional performance in elderly women and to determine optimal threshold values below which physical frailty occurs. Survey. University-based laboratory. Institutionalized women (N=123; mean age, 79.67 ± 5.2y). Not applicable. Force-velocity characteristics of the knee extensors were evaluated by using isometric, isokinetic, and ballistic tests on a motor-driven dynamometer. Isometric (ISOM) strength, dynamic strength, maximal speed of movement (SoM, unloaded), and speed of movement with standardized resistance of 20% (S(20)), 40% (S(40)), and 60% (S(60)) of the isometric maximum were recorded. MM of the upper leg was determined by using computed tomography. The modified Physical Performance Test (mPPT) was used to assess functional performance. Force-velocity characteristics (r varied from .31-.68) and MM (r=.41) correlated significantly with functional performance (PmPPT score (R(2)=.49), with SoM accounting for most of the variance. The threshold value that optimally differentiates between women with mild (mPPT score, 25-31) or without (mPPT score ≥32) physical frailty was 350°/s for SoM and 1.46N m/kg for ISOM strength. Sensitivity and specificity ranged from 74% to 77% and 71% to 77%, respectively. SoM is a key component in the onset of functional difficulties in elderly women. Exercise interventions specifically targeting muscle power (by including exercises at high velocities) thus might be crucial to prevent functional decline. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  4. Muscle length effect on corticospinal excitability during maximal concentric, isometric and eccentric contractions of the knee extensors.

    Science.gov (United States)

    Doguet, Valentin; Nosaka, Kazunori; Guével, Arnaud; Thickbroom, Gary; Ishimura, Kazuhiro; Jubeau, Marc

    2017-11-01

    What is the central question of this study? Does sensory input from peripheral mechanoreceptors determine the specific neural control of eccentric contractions? How corticospinal excitability (i.e. muscle responses to motor cortex stimulation) is affected by muscle length has never been investigated during eccentric contractions. What is the main finding and its importance? Muscle length does not influence corticospinal excitability during concentric and isometric maximal contractions, but does during eccentric maximal contractions. This indicates that neural control in eccentric contractions differs from that in concentric and isometric contractions. Neural control of eccentric contractions differs from that of concentric and isometric contractions, but no previous study has compared responses to motor cortex stimulations at long muscle lengths during such contraction types. In this study, we compared the effect of muscle length on corticospinal excitability between maximal concentric, isometric and eccentric contractions of the knee extensors. Twelve men performed 12 maximal concentric, isometric and eccentric voluntary contractions (36 contractions in total), separated by a 5 min rest between contraction types. The 12 contractions for the same contraction type were performed every 10 s, and transcranial magnetic stimulations (first eight contractions) and electrical femoral nerve stimulations (last four contractions) were superimposed alternately at 75 and 100 deg of knee flexion. Average motor evoked potential amplitude, normalized to the maximal M wave amplitude (MEP/M) and cortical silent period duration were calculated for each angle and compared among the contraction types. The MEP/M was lower (-23 and -28%, respectively) during eccentric than both concentric and isometric contractions at 75 deg, but similar between contraction types at 100 deg (P eccentric than both concentric and isometric contractions at 75 deg, but longer (+11 and +9

  5. Hip-abductor fatigue and single-leg landing mechanics in women athletes.

    Science.gov (United States)

    Patrek, Mary F; Kernozek, Thomas W; Willson, John D; Wright, Glenn A; Doberstein, Scott T

    2011-01-01

    Reduced hip-abductor strength and muscle activation may be associated with altered lower extremity mechanics, which are thought to increase the risk for anterior cruciate ligament injury. However, experimental evidence supporting this relationship is limited. To examine the changes in single-leg landing mechanics and gluteus medius recruitment that occur after a hip-abductor fatigue protocol. Descriptive laboratory study. Twenty physically active women (age  =  21.0 ± 1.3 years). Participants were tested before (prefatigue) and after (postfatigue) a hip-abductor fatigue protocol consisting of repetitive side-lying hip abduction. Outcome measures included sagittal-plane and frontal-plane hip and knee kinematics at initial contact and at 60 milliseconds after initial contact during 5 single-leg landings from a height of 40 cm. Peak hip and knee sagittal-plane and frontal-plane joint moments during this time interval were also analyzed. Measures of gluteus medius activation, including latency, peak amplitude, and integrated signal, were recorded. A small (hip-abduction angle at initial contact and a small (hip at initial contact or at 60 milliseconds after initial contact. Peak external knee-adduction moment decreased 27% and peak hip adduction moment decreased 24% during the postfatigue landing condition. Gluteus medius activation was delayed after the protocol, but no difference in peak or integrated signal was seen during the landing trials. Changes observed during single-leg landings after hip-abductor fatigue were not generally considered unfavorable to the integrity of the anterior cruciate ligament. Further work may be justified to study the role of hip-abductor activation in protecting the knee during landing.

  6. The Comparison of Forces Applied to the Knee Extensor Mechanism during Stance Phase of Gait in Flat Footed Females Three Different in-Shoe Orthotics

    Directory of Open Access Journals (Sweden)

    Mohsen Razeghi

    2012-01-01

    Full Text Available Objective: It has been postulated that subtalar position and movement would influence the function of the foot and the lower limb’s biomechanical alignment as a whole. The aim of this study was to compare the changes of force applied to the knee extensor mechanism of the female subjects while applying three different in-shoe orthotic appliances. Materials & Methods: Feiss Line test was used to assign a group of 10 healthy female subjects aged at 19-25 years as flat foot group. Retro reflective calibration and tracking markers were placed on the subjects over anatomically relevant locations. Kinematic and kinetic data were collected by employing a three dimensional motion capture system (Qualisys®Ltd, Sweden and a force platform (Kistler®, Switzerland respectively, while subjects walked at their preferred speed with 3 different in-shoe orthotics: simple insole, insole with medial arch support, insole with medial arch support and medial heel wedge, and insole with medial arch support and lateral forefoot wedge. Results: A statistically significant lower amount of the force applied to the extensor mechanism was found while applying medial arch support combined with lateral wedge (P=0.005. Conclusion: It could be concluded that changes of the different foot insoles would alter the force applied to the knee extensor mechanism. Results of this study emphasize the immediate effect of applying a medial arch support combined lateral wedge on reduction of the force applied to the extensor mechanism through which decrease a tendency towards musculoskeletal injuries.

  7. Relationship between the Modified Modified Ashworth Scale and the Biomechanical Measure in Assessing Knee Extensor Muscle Spasticity in Patients with Post-Stroke Hemiparesia:A Pilot Study

    Directory of Open Access Journals (Sweden)

    N. Nakhostin Ansari

    2014-07-01

    Full Text Available Introduction & Objective: The Modified Modified Ashworth Scale (MMAS is a clinical meas-ure that has been recently developed for the assessment of muscle spasticity. There is a dearth of research on the validity of the MMAS. The aim of the present study was to investi-gate the relationship between the MMAS and the biomechanical measure of work-velocity slope in assessing knee extensor muscle spasticity in patients with hemiparesia. Materials & Methods: Fourteen patients with post-stroke hemiparesia were included in this cross sectional study. Knee extensor spasticity was assessed with MMAS. An isokinetic dy-namometer was used to impose knee passive flexion with the angular velocity of 10, 30, 60, and 90 °/Sec to measure Torque-angle data. Work (Joule was calculated at each velocity to determine the slope of the work-velocity curves as the biomechanical measure of muscle spasticity. Results: The mean work decreased as the velocity increased but was not statistically signifi-cant (P = 0.07. The mean slope was – 0.35 [J /(°/Sec]. There was no significant correlation between the MMAS and the work-velocity slope (r =0.31, P = 0.28. Conclusion: There was no significant relationship between the MMAS and the biomechanical measure of work-velocity slope. Further studies with larger sample size are suggested. (Sci J Hamadan Univ Med Sci 2014; 21 (2: 131-136

  8. Effect of exercise-induced enhancement of the leg-extensor muscle-tendon unit capacities on ambulatory mechanics and knee osteoarthritis markers in the elderly.

    Directory of Open Access Journals (Sweden)

    Kiros Karamanidis

    Full Text Available Leg-extensor muscle weakness could be a key component in knee joint degeneration in the elderly because it may result in altered muscular control during locomotion influencing the mechanical environment within the joint. This work aimed to examine whether an exercise-induced enhancement of the triceps surae (TS and quadriceps femoris (QF muscle-tendon unit (MTU capacities would affect mechanical and biological markers for knee osteoarthritis in the elderly.Twelve older women completed a 14-week TS and QF MTU exercise intervention, which had already been established as increasing muscle strength and tendon stiffness. Locomotion mechanics and serum cartilage oligomeric matrix protein (COMP levels were examined during incline walking. MTU mechanical properties were assessed using simultaneously ultrasonography and dynamometry.Post exercise intervention, the elderly had higher TS and QF contractile strength and tendon-aponeurosis stiffness. Regarding the incline gait task, the subjects demonstrated a lower external knee adduction moment and lower knee adduction angular impulse during the stance phase post-intervention. Furthermore, post-intervention compared to pre-intervention, the elderly showed lower external hip adduction moment, but revealed higher plantarflexion pushoff moment. The changes in the external knee adduction moment were significantly correlated with the improvement in ankle pushoff function. Serum COMP concentration increased in response to the 0.5-h incline walking exercise with no differences in the magnitude of increment between pre- and post-intervention.This work emphasizes the important role played by the ankle pushoff function in knee joint mechanical loading during locomotion, and may justify the inclusion of the TS MTU in prevention programs aiming to positively influence specific mechanical markers for knee osteoarthritis in the elderly. However, the study was unable to show that COMP is amenable to change in the elderly

  9. Single-leg squats can predict leg alignment in dancers performing ballet movements in “turnout”

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    Hopper LS

    2016-11-01

    Full Text Available Luke S Hopper,1 Nahoko Sato,2 Andries L Weidemann1 1Western Australian Academy of Performing Arts, Edith Cowan University, Mt Lawley, WA, Australia; 2Department of Physical Therapy, Nagoya Gakuin University, Seto, Japan Abstract: The physical assessments used in dance injury surveillance programs are often adapted from the sports and exercise domain. Bespoke physical assessments may be required for dance, particularly when ballet movements involve “turning out” or external rotation of the legs beyond that typically used in sports. This study evaluated the ability of the traditional single-leg squat to predict the leg alignment of dancers performing ballet movements with turnout. Three-dimensional kinematic data of dancers performing the single-leg squat and five ballet movements were recorded and analyzed. Reduction of the three-dimensional data into a one-dimensional variable incorporating the ankle, knee, and hip joint center positions provided the strongest predictive model between the single-leg squat and the ballet movements. The single-leg squat can predict leg alignment in dancers performing ballet movements, even in “turned out” postures. Clinicians should pay careful attention to observational positioning and rating criteria when assessing dancers performing the single-leg squat. Keywords: injury, motion capture, clinical assessment

  10. Infusion of ATP increases leg oxygen delivery but not oxygen uptake in the initial phase of intense knee-extensor exercise in humans

    DEFF Research Database (Denmark)

    Nyberg, Michael Permin; Christensen, Peter Møller; Mortensen, Stefan Peter

    2014-01-01

    The present study examined whether an increase in leg blood flow and oxygen delivery at the onset of intense exercise would speed the rate of rise in leg oxygen uptake. Nine healthy men (25 ± 1 years old, mean ± SEM) performed one-leg knee-extensor exercise (62 ± 3 W, 86 ± 3% of incremental test ...... release was lower after 60, 120 and 180 s of exercise with ATP infusion. These results suggest that O2 delivery is not limiting the rise in skeletal muscle oxygen uptake in the initial phase of intense exercise....

  11. Ruptura bilateral e simultânea do mecanismo extensor do joelho em um pré-adolescente: relato de caso Simultaneous bilateral tear of the knee extensor mechanism in a pre-adolescent: case report

    Directory of Open Access Journals (Sweden)

    Rodrigo Pires e Albuquerque

    2012-10-01

    Full Text Available A ruptura do tendão patelar de um lado e um sleeve fracture contralateral em um pré-adolescente são uma lesão rara. Nós relatamos um caso em um pré-adolescente que caiu enquanto saltava durante uma partida de futebol. Não foram diagnosticados fatores predisponentes. As lesões foram tratadas com os reparos cirúrgicos e suturas transósseas. O objetivo desta pesquisa foi apresentar um caso de ruptura concorrente e espontânea do mecanismo extensor do joelho em um pré-adolescente.Unilateral tearing of a patellar tendon and a contralateral sleeve fracture in a pre-adolescent are rare lesions. We report a case in which a pre-adolescent sustained a fall while jumping during a soccer match. No predisposing risk factors were identified. The injuries were treated with surgical repairs and transosseous suturing. The aim of this study was to present a case of spontaneous concurrent tearing of the extensor mechanism of the knee in a pre-adolescent.

  12. An Evaluation of the Correlation between the Free Moments Applied on the Lower Extremity and the Knee Extensor Mechanism Force in Pronated Foot Subjects during the Stance Phase of Gait

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    Farzaneh Yazdani

    2016-12-01

    Full Text Available Background: Due to the rotatory nature of the excessive subtalar pronation and the possible impairment of the tibial rotation-knee flexion mechanism, changes of the free moment (FM and changes of the extensor mechanism force are expected in hyper-pronated foot subjects. The purpose of this study was to evaluate the correlation between the FM applied on the lower extremity and the knee extensor mechanism force in subjects with flexible pronated feet. Methods: Fifteen asymptomatic female subjects (21.32±1.66 y, 56.30±6.08 kg, 159±6.3 cm participated in the study. Excessive subtalar pronation was determined by measuring the resting calcaneal stance position (RCSP in the frontal plane during weight bearing. A neutrally aligned foot was defined as having an RCSP between 2° of inversion and 2° of eversion. On the other hand, a flat foot had an RCSP of more than or equal to 4° of eversion. Both kinetic and kinematic data were collected using a six-camera motion analysis system and a single force plate. Three successful barefoot walking trials were recorded at selfselected speeds. The extensor mechanism force and the adductory component of the free moment (ADD FM were calculated. The correlation between the ADD FM and the knee extensor mechanism force was examined using the Pearson correlation test. Results: The Pearson correlation analysis showed a high positive correlation between the ADD FM and the extensor mechanism force (r=0.917, P<0.001. Conclusion: Excessive subtalar pronation, along with a possible impairment of the tibial rotation-knee flexion mechanism, may affect the extensor mechanism force at the knee joint. From a clinical perspective, the possible biomechanical linkage between the knee and the foot complex in the physical examination and treatment of patients should be considered.

  13. Effects of Russian current and low-frequency pulsed current on discomfort level and current amplitude at 10% maximal knee extensor torque.

    Science.gov (United States)

    Vaz, Marco Aurélio; Aragão, Fernando Amâncio; Boschi, Émerson S; Fortuna, Rafael; Melo, Mônica de Oliveira

    2012-11-01

    Low-frequency pulsed current (LFPC) and Russian current (RC), a type of kilohertz-frequency alternating current, have been frequently used for muscle strengthening in rehabilitation programs. Despite the popularity of these current types, it is unclear which is most effectively able to generate a similar submaximal torque with minimal discomfort and current amplitude. To compare discomfort and current amplitude between LFPC and RC to achieve a knee extensor torque of 10% of the maximal isometric voluntary contraction (MIVC). Twenty-two healthy subjects were subjected to three electrically elicited knee extensor submaximal contractions (10% MIVC) that were sustained for 10 seconds. The current amplitude required to achieve 10% MIVC and subjective discomfort were assessed directly by the electrical stimulator and with the Visual Analogue Pain Scale, respectively. A paired t-test was used to determine differences between the electrical currents (α = 0.05). LFPC required significantly lower current amplitude (15%) and a lower discomfort level (50%) to achieve 10% of MIVC compared to RC. LFPC current seems to be more effective than RC with respect to discomfort level and current amplitude to produce 10% of MIVC.

  14. Single leg stance control in individuals with symptomatic gluteal tendinopathy.

    Science.gov (United States)

    Allison, Kim; Bennell, Kim L; Grimaldi, Alison; Vicenzino, Bill; Wrigley, Tim V; Hodges, Paul W

    2016-09-01

    Lateral hip pain during single leg loading, and hip abductor muscle weakness, are associated with gluteal tendinopathy, but it has not been shown how or whether kinematics in single leg stance differ in those with gluteal tendinopathy. To compare kinematics in preparation for, and during, single leg stance between individuals with and without gluteal tendinopathy, and the effect of hip abductor muscle strength on kinematics. Twenty individuals with gluteal tendinopathy and 20 age-matched pain-free controls underwent three-dimensional kinematic analysis of single leg stance and maximum isometric hip abductor strength testing. Maximum values of hip adduction, pelvic obliquity (contralateral pelvis rise/drop), lateral pelvic translation (ipsilateral/contralateral shift) and ipsilateral trunk lean during preparation for leg lift and average values in steady single leg stance, were compared between groups using an analysis of covariance, with and without anthropometric characteristics and strength as covariates. Individuals with gluteal tendinopathy demonstrated greater hip adduction (standardized mean difference (SMD)=0.70, P=0.04) and ipsilateral pelvic shift (SMD=1.1, P=0.002) in preparation for leg lift, and greater hip adduction (SMD=1.2, P=0.002) and less contralateral pelvic rise (SMD=0.86, P=0.02) in steady single leg stance than controls. When including strength as a covariate, only between-group differences in lateral pelvic shift persisted (SMD=1.7, P=0.01). Individuals with gluteal tendinopathy use different frontal plane kinematics of the hip and pelvis during single leg stance than pain-free controls. This finding is not influenced by pelvic dimension or the potentially modifiable factor of body mass index, but is by hip abductor muscle weakness. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. BUILDING A BETTER GLUTEAL BRIDGE: ELECTROMYOGRAPHIC ANALYSIS OF HIP MUSCLE ACTIVITY DURING MODIFIED SINGLE-LEG BRIDGES.

    Science.gov (United States)

    Lehecka, B J; Edwards, Michael; Haverkamp, Ryan; Martin, Lani; Porter, Kambry; Thach, Kailey; Sack, Richard J; Hakansson, Nils A

    2017-08-01

    Gluteal strength plays a role in injury prevention, normal gait patterns, eliminating pain, and enhancing athletic performance. Research shows high gluteal muscle activity during a single-leg bridge compared to other gluteal strengthening exercises; however, prior studies have primarily measured muscle activity with the active lower extremity starting in 90 ° of knee flexion with an extended contralateral knee. This standard position has caused reports of hamstring cramping, which may impede optimal gluteal strengthening. The purpose of this study was to determine which modified position for the single-leg bridge is best for preferentially activating the gluteus maximus and medius. Cross-Sectional. Twenty-eight healthy males and females aged 18-30 years were tested in five different, randomized single-leg bridge positions. Electromyography (EMG) electrodes were placed on subjects' gluteus maximus, gluteus medius, rectus femoris, and biceps femoris of their bridge leg (i.e., dominant or kicking leg), as well as the rectus femoris of their contralateral leg. Subjects performed a maximal voluntary isometric contraction (MVIC) for each tested muscle prior to performing five different bridge positions in randomized order. All bridge EMG data were normalized to the corresponding muscle MVIC data. A modified bridge position with the knee of the bridge leg flexed to 135 ° versus the traditional 90 ° of knee flexion demonstrated preferential activation of the gluteus maximus and gluteus medius compared to the traditional single-leg bridge. Hamstring activation significantly decreased (p bridge by flexing the active knee to 135 ° instead of 90 ° minimizes hamstring activity while maintaining high levels of gluteal activation, effectively building a bridge better suited for preferential gluteal activation. 3.

  16. Isokinetic assessment of knee flexor/extensor muscular strength in elderly women Avaliação isocinética do torque muscular flexor-extensor do joelho em mulheres com idade entre 75-83 anos

    Directory of Open Access Journals (Sweden)

    Marcos de Amorim Aquino

    2002-08-01

    Full Text Available OBJECTIVE: To assess knee flexor-extensor muscular strength in elderly women with no previous history of musculoskeletal disorders on the lower limbs using an isokinetic dynamometer, in order to obtain data that could be used as a comparative parameter in the evaluation of elderly women with knee disorders, thus facilitating a better rehabilitation of these patients. METHODS: Twenty-six volunteers aged 75 to 83 years were studied using a Cybex® 6000 isokinetic dynamometer. The chosen angular velocity was 60 º/s, and concentric exercise was used for either flexion or extension. The studied parameters were: peak torque, angle of peak torque, and flexor-extensor torque rate. RESULTS: There were no differences between dominant (D and nondominant (ND knee peak torque values. This was true for both flexor (D = 42.46 ± 9.09 Nm / ND = 40.65 ± 9.38 Nm and extensor (D = 76.92 ± 13.97 Nm / ND = 77.65 ± 15.21 Nm movements. The descriptive statistical analysis of the values obtained for the flexor-extensor peak torque rate and for the angle of occurrence of peak torque was the same for the dominant and nondominant sides. CONCLUSIONS: The values of peak torque for the contralateral side can be used as a reference during rehabilitation of elderly women with acute disease of the knee, and the angular velocity of 60 º/s is proper and safe for isokinetic assessment of elderly people.OBJETIVO: Avaliar, isocineticamente, o torque dos músculos flexores e extensores dos joelhos de mulheres idosas sem afecções do sistema músculo-esquelético em membros inferiores, obtendo dados que possam servir como parâmetro de comparação na avaliação de mulheres idosas portadoras de afecções nos joelhos, colaborando para uma melhor reabilitação dessas pacientes. CASUÍSTICA E MÉTODOS: Vinte e seis voluntárias foram avaliadas. O estudo foi realizado através de um dinamômetro isocinético marca CYBEXâ modelo 6000 na velocidade angular de 60º/s. O tipo do

  17. Effect of ankle braces on lower extremity joint energetics in single-leg landings.

    Science.gov (United States)

    Gardner, Jacob K; McCaw, Steven T; Laudner, Kevin G; Smith, Peter J; Stafford, Lindsay N

    2012-06-01

    Ankle sprains are one of the most common injuries in competitive and recreational athletics. Studies have shown that the use of prophylactic ankle braces effectively reduces the frequency of ankle sprains in athletes. However, although it is generally accepted that the ankle braces are effective at reducing frontal plane motion, some researchers report that the design of the brace may also reduce ankle sagittal plane motion. The purpose of this study was to quantify lower extremity joint contributions to energy absorption during single-legged drop landings in three ankle brace conditions (no brace, boot brace, and hinged brace). Eleven physically active females experienced in landing and free of lower extremity injury (age = 22.3 ± 1.7 yr, height = 1.66 ± 0.04 m, mass = 58.43 ± 5.83 kg) performed 10 single-leg drop landings in three conditions (one unbraced, two braced) from a 0.33-m height. Measurements taken were hip, knee, and ankle joint impulse; hip, knee, ankle, and total work; and hip, knee, and ankle joint relative work. Total energy absorption remained consistent across the braced conditions (P = 0.057). Wearing the boot brace reduced relative ankle work (P = 0.04, Cohen d = 0.43) but did not change relative knee (P = 0.08, Cohen d = 0.32) or hip (P = 0.14, Cohen d = 0.20) work compared with the no-brace condition. In an ankle-braced condition, ankle, knee, and hip energetics may be altered depending on the design of the brace.

  18. Biomechanical analysis of the single-leg decline squat

    NARCIS (Netherlands)

    Zwerver, J.; Bredeweg, S. W.; Hof, A. L.

    Background: The single-leg squat on a 25 decline board has been described as a clinical assessment tool and as a rehabilitation exercise for patients with patellar tendinopathy. Several assumptions have been made about its working mechanism on patellar load and patellofemoral forces, but these are

  19. Effects of different methods of antagonist muscles pre-activation on knee extensors neuromuscular responses Efeitos da ordem de pré-ativação dos músculos antagonistas nas respostas neuromusculares dos extensores do joelho

    Directory of Open Access Journals (Sweden)

    Rodrigo L. Carregaro

    2011-12-01

    Full Text Available BACKGROUND: Pre-activation of antagonistic muscles is used in different modalities of exercise and neuromuscular rehabilitation protocols, but its effectiveness is still controversial. OBJECTIVE: To verify the impact of two different methods of pre-activation of knee antagonist muscles in the neuromuscular performance and electromyographic activity of knee extensors. METHODS: Fifteen healthy men (23.9±4.2 years of age, 1.78±0.08 meters and 81.4±10.7 kg performed, on different days, two protocols of isokinetic muscle contraction with 4 sets of 10 repetitions at 60°.s-1 and 1 minute between sets: (1 Reciprocal Contraction (RC: reciprocal concentric exercise of agonist/antagonist muscles (knee flexion [KF] immediately followed by knee extension [KE] and (2 Superset (SS: alternated concentric exercise of agonist/antagonist muscles (KF set followed by a set of KE. A repeated measures ANOVA with least-significant difference post-hoc test was used to detect differences between protocols. RESULTS: There were no significant differences between protocols (p>0.05 for peak torque (PT and total work (Tw. On the SS protocol there was a significant decrease in Tw on the last two sets (pCONTEXTUALIZAÇÃO: A pré-ativação de músculos antagonistas é utilizada em diferentes modalidades de exercício e em diferentes protocolos de reabilitação neuromuscular, porém suas respostas ainda são controversas. OBJETIVO: Verificar o impacto de duas diferentes estratégias de pré-ativação de músculos antagonistas no desempenho neuromuscular e na atividade eletromiográfica dos extensores do joelho. MÉTODOS: Quinze homens sadios (23,9±4,2 anos; 1,78±0,08 m e 81,4±10,7 kg realizaram, em dias distintos, dois protocolos de ações musculares isocinéticas com quatro séries de dez repetições a 60°.s-1 e intervalo de 1 minuto entre séries: 1 contração recíproca (CR: exercício concêntrico recíproco de antagonistas/agonistas (uma repetição de flex

  20. Effects of isokinetic eccentric training on knee extensor and flexor torque and on gait of individuals with long term ACL reconstruction: A controlled clinical trial

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    Heleodório Honorato dos Santos

    2014-12-01

    Full Text Available This study investigated the effects of the isokinetic eccentric training (IET on the knee extensor and flexor torque and kinematic gait parameters in individuals with ACL reconstruction. Sixteen men with ACL reconstructed (ACLr whose torque and the gait were evaluated, before and after 12 weeks of IET, was compared to a control group (14 individuals. Student t, MANOVA and ANOVA tests were performed with 5% of significance. The training increased the isometric, concentric at 30 and 120º/s (p < .05 and eccentric at 30º/s (p < .01 extensor torque on the affected limb (AL, and eccentric at 30 and 120º/s (p < .01, on the non-affected limb (NAL. In the flexors, there was an increase on the torque: isometric, concentric at 30º/s and eccentric at 30 and 120º/s (p < .01 in AL and in eccentric at 30 (p < .05 and 120º/s (p< .01 in NAL. With respect to the angular and spatio-temporal variables gait, there was no difference between pre-and post-training in LCAr group. Compared to control group, the cycle time, in two members, was lower in LCAr group, and stride length and cadence were higher in the AL of the LCAr (p < .05. Moreover, the knee flexion-extension angles (minimum and maximum remained lower in LCAr, pre- and post-training (p < .01. The torque gain associated with eccentric isokinetic training did not affect the kinematic parameters of gait in patients undergoing ACL reconstruction.

  1. Effects of menarcheal age on the anterior cruciate ligament injury risk factors during single-legged drop landing in female artistic elite gymnasts.

    Science.gov (United States)

    Kim, Kew-Wan; Lim, Bee-Oh

    2014-11-01

    Although numerous studies have demonstrated the relationship between maturation and lower extremity biomechanics during landing in team sport athletes, we are presently uninformed of any research that examined the single-legged drop landing biomechanics of gymnasts. The purpose of this study is to investigate the effects of the menarcheal age on the lower extremity biomechanics during a single-legged drop landing in female artistic elite gymnasts. Twenty-two female artistic elite gymnasts, between 9 and 36 years of age, participated in this study. The participants were divided into two groups pre- (n = 11) and post- (n = 11) menarche and asked to perform a single-legged drop landing on top of a 30 cm platform and land on a force plate. The statistical analysis consisted of the multivariate analysis with the level of significance set at p knee flexion angle and increase in their maximum knee abduction angle, maximum internal tibial rotation angle, maximum knee abduction moment, and hamstring-quadriceps muscle activity ratio compared with the pre-menarche group during the single-legged drop landing. The post-menarche group showed an increased noncontact anterior cruciate ligament injury risk, due to their greater knee loads, compared with the pre-menarche group.

  2. Can a wearable strain sensor based on a carbon nanotube network be an alternative to an isokinetic dynamometer for the measurement of knee-extensor muscle strength?

    Science.gov (United States)

    Benlikaya, Ruhan; Ege, Yavuz; Pündük, Zekine; Slobodian, Petr; Meriç, Gökhan

    2017-04-01

    This study aimed to find out whether a wearable strain sensor including thermoplastic polyurethane composite with a multi-walled carbon nanotube network could be a viable alternative to an isokinetic dynamometer for the measurement of knee-extensor muscle strength. For the first time, the voltage-torque and angle-time relations of the sensor were determined to allow a comparison between the angle-dependent torque changes of the dynamometer and the sensor. This comparison suggested that the torque-angle relations of the dynamometer and the sensor did not have the same characteristics. In this regard, the sensor may be used in the torque measurements due to the moderate correlation between the torque values determined via the isokinetic dynamometer and the sensor and due to the significant difference between low and high torque values of the sensor. By the same token, the torque-angle graph of the sensor may be more informative than that of the dynamometer in evaluation of knee problems.

  3. Sex difference in age-related changes in knee extensor strength and power production during a 10-times-repeated sit-to-stand task in Japanese elderly.

    Science.gov (United States)

    Yanagawa, Naoko; Shimomitsu, Teruichi; Kawanishi, Masashi; Fukunaga, Tetsuo; Kanehisa, Hiroaki

    2015-11-14

    For middle-aged and elderly women, age-related decline in an index representing power production during STS task (STS-PI), calculated by using an equation reported previously, has been shown to be greater than that in the force generation capability of lower extremity. Whether this is specific to women remains unclear. This study examined how the age-related changes in knee extensor strength and power production during STS differ between Japanese men and women aged 65 years or older. The time taken for a 10-times-repeated STS test (STS time) and force developed during maximal voluntary isometric knee extension (KE-F) were determined in Japanese younger-old (262 men and 285 women) aged 65-74 years and older-old (96 men and 89 women) aged 75-90 years. STS-PI was calculated using the following equation: STS-PI = (body height - 0.4) × body mass × 10/STS time. KE-F and STS-PI were significantly greater in the younger-old than in the older-old group (p movement such as STS in older women than in older men.

  4. Correlation between dynamic postural stability and muscle strength, anterior instability, and knee scale in anterior cruciate ligament deficient knees.

    Science.gov (United States)

    Park, Won-Hah; Kim, Do-Kyung; Yoo, Jae Chul; Lee, Yong Seuk; Hwang, Ji-Hye; Chang, Moon Jong; Park, Yong Serk

    2010-08-01

    The purpose of this study was to assess the correlations between dynamic postural stability and muscle strength, anterior instability, and knee scores in anterior cruciate ligament (ACL) deficient knees. We examined 40 male patients with ACL injury prior to surgery. Maximal torques of flexors and extensors of the injured knee at 60 and 180 degrees /s were evaluated using an isokinetic testing device. Anterior translations of the tibia were measured using a KT-2000 arthrometer, and dynamic postural stabilities were measured during single-leg stance using the Biodex Stability System (BSS). Knee statuses were evaluated using Lysholm and International Knee Documentation Committee (IKDC) knee scores. Correlations between dynamic postural stability and muscle strength, anterior instability, and knee scores were determined. Significant correlations were found between maximal torques of the extensor of injured knees at 60 and 180 degrees /s (r = -0.52, p = 0.048 and r = -0.46, p = 0.019, respectively) and dynamic postural stability, and maximal torques of flexors of injured knees showed similar relations (r = -0.51, p = 0.0048 and r = -0.47, p = 0.016, respectively). Lysholm and IKDC knee scores were also found to be correlated with dynamic postural stability (r = -0.49, p = 0.001 and r = -0.52, p = 0.005, respectively). However, no correlation was found between grade of anterior translation measured using the KT-2000 arthrometer and dynamic postural stability (p = 1.0). Dynamic postural stability determined using the BSS appears to be influenced by muscle strength, as determined by isokinetic testing, but not with grade of anterior translation measured using a KT-2000 arthrometer. Subjective knee scores appear to improve in parallel with dynamic postural stability.

  5. Elevated gastrocnemius forces compensate for decreased hamstrings forces during the weight-acceptance phase of single-leg jump landing: implications for anterior cruciate ligament injury risk.

    Science.gov (United States)

    Morgan, Kristin D; Donnelly, Cyril J; Reinbolt, Jeffrey A

    2014-10-17

    Approximately 320,000 anterior cruciate ligament (ACL) injuries in the United States each year are non-contact injuries, with many occurring during a single-leg jump landing. To reduce ACL injury risk, one option is to improve muscle strength and/or the activation of muscles crossing the knee under elevated external loading. This study's purpose was to characterize the relative force production of the muscles supporting the knee during the weight-acceptance (WA) phase of single-leg jump landing and investigate the gastrocnemii forces compared to the hamstrings forces. Amateur male Western Australian Rules Football players completed a single-leg jump landing protocol and six participants were randomly chosen for further modeling and simulation. A three-dimensional, 14-segment, 37 degree-of-freedom, 92 muscle-tendon actuated model was created for each participant in OpenSim. Computed muscle control was used to generate 12 muscle-driven simulations, 2 trials per participant, of the WA phase of single-leg jump landing. A one-way ANOVA and Tukey post-hoc analysis showed both the quadriceps and gastrocnemii muscle force estimates were significantly greater than the hamstrings (p<0.001). Elevated gastrocnemii forces corresponded with increased joint compression and lower ACL forces. The elevated quadriceps and gastrocnemii forces during landing may represent a generalized muscle strategy to increase knee joint stiffness, protecting the knee and ACL from external knee loading and injury risk. These results contribute to our understanding of how muscle's function during single-leg jump landing and should serve as the foundation for novel muscle-targeted training intervention programs aimed to reduce ACL injuries in sport. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Knee extensor torque of men with early degrees of osteoarthritis is associated with pain, stiffness and function Homens com graus iniciais de osteoartrite apresentam correlação entre torque extensor do joelho e dor, rigidez e função

    Directory of Open Access Journals (Sweden)

    Paula R. M. S. Serrão

    2012-08-01

    Full Text Available BACKGROUND: Osteoarthritis (OA is a chronic-degenerative disease. The knee is the most commonly affected joint and the symptoms are generally attributed to quadriceps muscle weakness. However, few studies have evaluated this relationship in a population with early stages of knee OA. OBJECTIVE: To investigate whether a correlation among the knee extensor torque and the three subscales of the WOMAC questionnaire in men with early stages of knee OA exists. METHOD: Twenty-one men with knee OA grades I or II (according to Kellgren and Lawrence criteria participated in this study. The concentric and eccentric knee extensor torque were assessed using a Biodex System 3 Pro® isokinetic dynamometer, at a speed of 90º/s. Self-reported symptoms and disability were assessed using the WOMAC questionnaire. Spearman's correlation coefficient was used to test the relationship between the dependent variables (three subscales of WOMAC questionnaire and the independent variables (average knee extensor peak torque. RESULTS: We found a strong negative correlation between the concentric extensor torque and pain (r=-0.7, pCONTEXTUALIZAÇÃO: A osteoartrite (OA é uma doença crônico-degenerativa. O joelho é a articulação mais afetada, e os sintomas geralmente são atribuídos à fraqueza do músculo quadríceps. Entretanto, poucos estudos têm avaliado essa relação em indivíduos com graus iniciais de OA. OBJETIVO: Verificar se existe correlação entre o torque extensor do joelho e as seções dor, rigidez e função física do questionário WOMAC de homens com OA de joelho nos graus iniciais. MÉTODO: Participaram deste estudo 21 homens com OA de joelho graus I ou II (segundo critérios de Kelgren e Lawrence. Foi avaliado o torque extensor concêntrico e o excêntrico do joelho por meio do dinamômetro isocinético (Biodex System 3 Pro®, na velocidade de 90º/s. O autorrelato de sintomas e incapacidades foi avaliado por meio do questionário WOMAC. O

  7. Influência do treinamento excêntrico nas razões de torque de flexores/extensores do joelho Knee torque ratio after eccentric training

    Directory of Open Access Journals (Sweden)

    Fábio Juner Lanferdini

    2010-03-01

    intragroups between assessments, with (significance level set at p<0.05. In EG a reduction in torque ratios was found from the initial assessment (AS1 to the other three ones: AS1x AS2, p=0.005; AS1x AS3, p=0.001; and AS1x AS4, p<0.001. At the last evaluation, EG torque ratios were lower than those of CG's (p=0.041. Eccentric training hence changes balance between knee flexor and extensor muscles: a 12-week training program leads to lower Hecc:Qecc ratio and to extensor torque increase, with no significant change in flexor torque, being thus suitable for rehabilitation aimed at strengthening knee extensor muscles.

  8. Correlation between the 8-repetition maximum test and isokinetic dynamometry in the measurement of muscle strength of the knee extensors: A concurrent validity study.

    Science.gov (United States)

    Taylor, J David; Fletcher, James P

    2013-05-01

    The 8-repetition maximum test has the potential to be a feasible, cost-effective method of measuring muscle strength for clinicians. The purpose of this study was to investigate the concurrent validity of the 8-repetition maximum test in the measurement of muscle strength by comparing the 8-repetition maximum test to the gold standard of isokinetic dynamometry. Thirty participants (15 males and 15 females, mean age = 23.2 years [standard deviation = 1.0]) underwent 8-repetition maximum testing and isokinetic dynamometry testing of the knee extensors (at 60, 120, and 240 degrees per second) on two separate sessions with 2-3 days between each mode of testing. Linear regression was used to assess the validity by comparing the findings between 8-repetition maximum testing and isokinetic dynamometry testing. Significant correlations were found between the 8-repetition maximum and isokinetic dynamometry peak torque at each testing velocity (r  =  0.71-0.85). The highest correlations were between the 8-repetition maximum and isokinetic dynamometry peak torques at 60 (r  =  0.85) and 120 (r  =  0.85) degrees per second. The findings of this study provide supportive evidence for the use of 8-repetition maximum testing as a valid, alternative method for measuring muscle strength.

  9. Tennis in hot and cool conditions decreases the rapid muscle torque production capacity of the knee extensors but not of the plantar flexors.

    Science.gov (United States)

    Girard, Olivier; Racinais, Sébastien; Périard, Julien D

    2014-04-01

    To assess the time course of changes in rapid muscle force/torque production capacity and neuromuscular activity of lower limb muscles in response to prolonged (∼2 h) match-play tennis under heat stress. The rates of torque development (RTD) and electromyographic activity (EMG; ie, root mean square) rise were recorded from 0 to 30, -50, -100 and -200 ms during brief (3-5 s) explosive maximal isometric voluntary contractions (MVC) of the knee extensors (KE) and plantar flexors (PF), along with the peak RTD within the entirety of the torque-time curve. These values were recorded in 12 male tennis players before (prematch) and after (postmatch, 24 and 48 h) match-play in HOT (∼37°C) and COOL (∼22°C) conditions. The postmatch core temperature was greater in the HOT (∼39.4°C) vs COOL (∼38.7°C) condition (ptorque. Furthermore, the rate of KE EMG activity rise remained unchanged. Conversely, the PF contractile RTD and rate of EMG activity rise were unaffected by the exercise or environmental conditions. In the KE, a reduction in maximal torque production capacity following prolonged match-play tennis appears to account for the decrease in the rate of torque development, independent of environmental conditions, while remaining unchanged in the PF.

  10. Acute effects of whole-body vibration on peak isometric torque, muscle twitch torque and voluntary muscle activation of the knee extensors.

    Science.gov (United States)

    Jordan, M; Norris, S; Smith, D; Herzog, W

    2010-06-01

    The purpose of this investigation was to compare the acute effects of whole-body vibration (WBV) with a static squat on resting muscle twitch torque, peak isometric torque and voluntary muscle activation of the knee extensors during an isometric maximal voluntary contraction (MVC). Twenty-four healthy, strength-trained males were recruited for this randomized, cross-over design investigation. The WBV treatment consisted of three sets of 60 s of vibration (30 Hz, +/-4 mm) while standing in a semi-squat position. Voluntary muscle activation, peak isometric torque during MVC and resting muscle twitch torque (RTT) through percutaneous femoral nerve stimulation were obtained before and following the treatment. Change in peak isometric torque, voluntary muscle activation and the RTT were calculated as the difference between pre- and post-treatment values. There was no observable post-activation potentiation of muscle twitch torque or enhancement in voluntary muscle activation or peak isometric torque. However, decreases in the peak isometric torque (P=0.0094) and voluntary muscle activation (P=0.0252) were significantly smaller post WBV interventions compared with the control treatment. Based on the current data, it is unclear whether or not this was attributable to the effects of WBV but further research into this possibility is warranted.

  11. How does postural stability following a single leg drop jump landing task relate to postural stability during a single leg stance balance task?

    NARCIS (Netherlands)

    Fransz, Duncan P.; Huurnink, Arnold; Kingma, Idsart; van Dieën, Jaap H.

    2014-01-01

    We aimed to verify whether the static phase after a single leg drop jump (DJ) landing on a force plate may serve as a proxy for a single leg stance (SLS) balance task, as this would increase the application possibilities of landing tasks in the evaluation of sensorimotor function in relation to

  12. Evaluation of a single leg stance balance test in children.

    Science.gov (United States)

    Zumbrunn, Thomas; MacWilliams, Bruce A; Johnson, Barbara A

    2011-06-01

    Balance is a major determinate of gait. In high functioning individuals without significant vestibular or vision impairments, a ceiling effect may be present when using a double limb support protocol to assess balance function. For these populations, a single leg stance protocol may be more suitable. 47 typically developing (TD) subjects and 10 patients with CEV performed a single leg stance test on a force plate. The center of pressure (COP) was determined and several COP derived variables were calculated. Included measurements were: standard deviation, maximum excursion, area, average radial displacement, path velocity and frequency of the COP. Directional components of suitable variables were used to analyze anterior/posterior and medial/lateral contributions. Correlations with age of TD subjects indicated that all balance variables except frequency were significantly correlated. Most parameters were highly inter-correlated. Age adjusted COP balance variables also correlated to the Bruininks-Oseretsky balance subtest. Highest correlations were determined by the maximum excursion and velocity of the COP in the anterior/posterior direction. Statistical comparisons between the CEV group and a 4-6 TD group indicated significant differences between groups for most COP balance parameters. These results indicated that a single limb balance assessment may be a useful assessment for determining balance impairments in higher functioning children with orthopedic impairments. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. EFFECTS OF PROLONGED TENDON VIBRATION STIMULATION ON ECCENTRIC AND CONCENTRIC MAXIMAL TORQUE AND EMGS OF THE KNEE EXTENSORS

    Directory of Open Access Journals (Sweden)

    Akinori Fukudomet

    2009-12-01

    Full Text Available The purpose of present study was to compare the effect of Ia afferent attenuation on the activity of alpha motor neuron (MN during concentric and eccentric action. Eight male subjects were enrolled in the present study. The experiments consisted of two sessions of MVC measurements, since all subjects performed both maximal concentric and eccentric action. EMG signals were simultaneously measured. To establish the baseline of strength, subjects were asked to perform MVC of knee extension in each session. After finishing the measurements, 20 min of vibration stimulation was applied. Immediately after finishing vibration stimulation, the MVC and AEMG were again measured. The means of MVC for concentric knee extension at pre and post- vibration stimulation were 192.2 ± 49.3 Nm and 162.3 ± 47.9 Nm, respectively. The means of MVC for eccentric knee extension at pre and post-vibration stimulation were 299.7 ± 77.0 Nm and 247.3 ± 88. 6 Nm, respectively. Two-factor repeated ANOVA detected significant differences in the MVC. Both main effects for pre-post condition (F(1,7=, p = 0.0033 and action (F(1,7=26.35, p = 0.0013 were noted. No interaction effect (action x condition was noted. The means of AEMG (vastus lateralis (VL, vastus medialis (VM, rectus femoris (RF at pre and post -vibration stimulation were decreased. Two-factor repeated ANOVA detected significant differences in AEMG (VM and VL. Both main effects for pre-post condition (VL;F(1,7=7.27, p = 0.0308, VM; F(1,7=9.55, p = 0.0175 and action (F(1,7=12.40, p = 0.0097 were noted in the VL and the VM but not in the RF. Furthermore, significant interaction (action x condition effect was noted in the VM (F(1,7=7.03, p = 0.0328 but not in the VL. The MVC and the EMG activity of the VL in response to the prolonged vibration stimulation were significantly reduced in eccentric contraction over concentric contraction. These results represented that a deactivation effect on the alpha MN of the VL during

  14. Lower eccentric hamstring strength and single leg hop for distance predict hamstring injury in PETE students.

    Science.gov (United States)

    Goossens, L; Witvrouw, E; Vanden Bossche, L; De Clercq, D

    2015-01-01

    Hamstring injuries have not been under research in physical education teacher education (PETE) students so far. Within the frame of the development of an injury prevention program, for this study we conducted an analysis of modifiable risk factors for hamstring injuries in PETE students. Hamstring injuries of 102 freshmen bachelor PETE students were registered prospectively during one academic year. Eighty-one students completed maximum muscle strength tests of hip extensors, hamstrings, quadriceps (isometric) and hamstrings (eccentric) at the start of the academic year. Sixty-nine of the latter completed a single leg hop for distance (SLHD). Risk factors for hamstring injuries were statistically detected using logistic regression. Sixteen hamstring injuries (0.16 injuries/student/academic year; 0.46 injuries/1000 h) occurred to 10 participants. Eight cases were included in the risk factor analysis. Lower eccentric hamstring strength (odds ratio (ODD) = 0.977; p = 0.043), higher isometric/eccentric hamstring strength ratio (ODD = 970.500; p = 0.019) and lower score on the SLHD (ODD = 0.884; p = 0.005) were significant risk factors for hamstring injury. A combination of eccentric hamstring strength test and SLHD could give a good risk analysis of hamstring injuries in PETE students. This might offer great perspectives for easily applicable screening in a clinical setting.

  15. Change in knee flexor torque after fatiguing exercise identifies previous hamstring injury in football players.

    Science.gov (United States)

    Lord, C; Ma'ayah, F; Blazevich, A J

    2018-03-01

    Muscular fatigue and interlimb strength asymmetry are factors known to influence hamstring injury risk; however, limb-specific exacerbation of knee flexor (hamstrings) torque production after fatiguing exercise has previously been ignored. To investigate changes in muscular force production before and after sport-specific (repeated-sprint) and non-specific (knee extension-flexion) fatiguing exercise, and explore the sensitivity and specificity of isokinetic endurance (ie, muscle-specific) and single-leg vertical jump (ie, whole limb) tests to identify previous hamstring injury. Twenty Western Australia State League footballers with previous unilateral hamstring injury and 20 players without participated. Peak concentric knee extensor and flexor (180°∙s -1 ) torques were assessed throughout an isokinetic endurance test, which was then repeated alongside a single-leg vertical jump test before and after maximal repeated-sprint exercise. Greater reductions in isokinetic knee flexor torque (-16%) and the concentric hamstring:quadriceps peak torque ratio (-15%) were observed after repeated-sprint running only in the injured (kicking) leg and only in the previously injured subjects. Changes in (1) peak knee flexor torque after repeated-sprint exercise, and (2) the decline in knee flexor torque during the isokinetic endurance test measured after repeated-sprint exercise, correctly identified the injured legs (N = 20) within the cohort (N = 80) with 100% specificity and sensitivity. Decreases in peak knee flexor torque and the knee flexor torque during an isokinetic endurance test after repeated-sprint exercise identified previous hamstring injury with 100% accuracy. Changes in knee flexor torque, but not SLVJ, should be tested to determine its prospective ability to predict hamstring injury in competitive football players. © 2017 The Authors. Scandinavian Journal of Medicine & Science In Sports Published by John Wiley & Sons Ltd.

  16. Atualização da anatomia do mecanismo extensor do joelho com uso de técnica de visualização tridimensional Updating of the anatomy of the extensor mechanism of the knee using a three-dimensional viewing technique

    Directory of Open Access Journals (Sweden)

    Diego Costa Astur

    2011-10-01

    Full Text Available O mecanismo extensor do joelho é uma estrutura complexa formada pelo músculo e tendão quadricipital, a patela, o tendão patelar e os ligamentos que os circundam e auxiliam na estabilização do joelho. Através do uso de técnica de visualização tridimensional de imagens do aparelho extensor do joelho pretendemos mostrar de forma didática as estruturas que compõem este complexo ósteo-músculo-ligamentar. Dissecção anatômica do joelho com ênfase nas estruturas do seu mecanismo extensor foi realizada seguida de fotografias com câmera e lentes adequadas para simulação da visão humana através de técnica de construção de imagem tridimensional. Em seguida, com a ajuda de software apropriado, as duas imagens da mesma estrutura de diferentes ângulos simulando a visão humana são sobrepostas com adição de camada polarizante, concluindo a construção da imagem anaglífica. As principais estruturas do mecanismo extensor do joelho podem ser observadas com efeito tridimensional. Dentre os principais benefícios relacionados a esta técnica, destacamos, além do ensino e estudo da anatomia musculoesquelética, o potencial uso em treinamento de procedimentos cirúrgicos e a realização de imagens em exames diagnósticos.The knee extensor mechanism is a complex structure formed by the quadriceps muscle and tendon, the patella, the patellar tendon and the ligaments that surround and help stabilize the knee. Through using a three-dimensional viewing technique on images of the knee extensor apparatus, we aimed to didactically show the structures that compose this bone-muscle-ligament complex. Anatomical dissection of the knee with emphasis on the structures of its extensor mechanism was performed, followed by taking photographs using a camera and lenses suitable for simulating human vision, through a technique for constructing three-dimensional images. Then, with the aid of appropriate software, pairs of images of the same structure from

  17. Whole body, long-axis rotational training improves lower extremity neuromuscular control during single leg lateral drop landing and stabilization.

    Science.gov (United States)

    Nyland, John; Burden, Robert; Krupp, Ryan; Caborn, David N M

    2011-05-01

    Poor neuromuscular control during sports activities is associated with non-contact lower extremity injuries. This study evaluated the efficacy of progressive resistance, whole body, long-axis rotational training to improve lower extremity neuromuscular control during a single leg lateral drop landing and stabilization. Thirty-six healthy subjects were randomly assigned to either Training or Control groups. Electromyographic, ground reaction force, and kinematic data were collected from three pre-test, post-test trials. Independent sample t-tests with Bonferroni corrections for multiple comparisons were used to compare group mean change differences (P≤0.05/21≤0.0023). Training group gluteus maximus and gluteus medius neuromuscular efficiency improved 35.7% and 31.7%, respectively. Training group composite vertical-anteroposterior-mediolateral ground reaction force stabilization timing occurred 1.35s earlier. Training group knee flexion angle at landing increased by 3.5°. Training group time period between the initial two peak frontal plane knee displacements following landing increased by 0.17s. Training group peak hip and knee flexion velocity were 21.2°/s and 20.1°/s slower, respectively. Time period between the initial two peak frontal plane knee displacements following landing and peak hip flexion velocity mean change differences displayed a strong relationship in the Training group (r(2)=0.77, P=0.0001) suggesting improved dynamic frontal plane knee control as peak hip flexion velocity decreased. This study identified electromyographic, kinematic, and ground reaction force evidence that device training improved lower extremity neuromuscular control during single leg lateral drop landing and stabilization. Further studies with other populations are indicated. Copyright © 2010 Elsevier Ltd. All rights reserved.

  18. The reliability and criterion validity of 2D video assessment of single leg squat and hop landing.

    Science.gov (United States)

    Herrington, Lee; Alenezi, Faisal; Alzhrani, Msaad; Alrayani, Hasan; Jones, Richard

    2017-06-01

    The objective was to assess the intra-tester, within and between day reliability of measurement of hip adduction (HADD) and frontal plane projection angles (FPPA) during single leg squat (SLS) and single leg landing (SLL) using 2D video and the validity of these measurements against those found during 3D motion capture. 15 healthy subjects had their SLS and SLL assessed using 3D motion capture and video analysis. Inter-tester reliability for both SLS and SLL when measuring FPPA and HADD show excellent correlations (ICC 2,1 0.97-0.99). Within and between day assessment of SLS and SLL showed good to excellent correlations for both variables (ICC 3,1 0.72-91). 2D FPPA measures were found to have good correlation with knee abduction angle in 3-D (r=0.79, p=0.008) during SLS, and also to knee abduction moment (r=0.65, p=0.009). 2D HADD showed very good correlation with 3D HADD during SLS (r=0.81, p=0.001), and a good correlation during SLL (r=0.62, p=0.013). All other associations were weak (r<0.4). This study suggests that 2D video kinematics have a reasonable association to what is being measured with 3D motion capture. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. The correlation between isokinetic strength of knee extensors and vertical jump performance in adolescent soccer players in an annual training cycle

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    Michal Lehnert

    2013-03-01

    Full Text Available BACKGROUND: Isokinetic testing is often used to provide coaches with important information about the physical status of athletes. Therefore, a number of studies focused on the assessment of the relationship between isokinetic and functional tests including soccer. The results of a limited number of studies indicate that the relationship changes in different training periods. OBJECTIVE: The aim of the study was to determine the relationship between the characteristics of the isokinetic strength of knee extensors and vertical jump performance in three different periods of the annual training cycle in adolescent soccer players. METHODS: A group of adolescent soccer players (n = 16; average age 16.7 ± 0.7 years was tested at the end of the competitive season, at the beginning of the off-season and during the sixth week of a new competitive season. The isokinetic concentric peak torque (PT, peak power (Pmax and time to peak torque (TPT of the dominant leg and non-dominant leg were measured at angular velocities of 60°•s–1, 180°•s–1, 360°•s–1. The explosive strength of the lower extremities was measured using the countermovement jump with free arms (CMJF method and countermovement jump with the arms crossed over the chest. Based on literary reviews, a logically significant value of the correlation was set at > 0.30. RESULTS: The correlations between the isokinetic strength characteristics and vertical jump performance irrespective of the training period were low to moderate; 56% of the correlations were > 0.30. In the different periods of the annual training cycle, the occurrence of correlations > 0.30 as well as their value varied – 67% at the end of the competitive season, 31% at the beginning of the off-season and 64% at the beginning of the competitive season. For both types of jumps, the correlations for Pmax and PT parameters were the lowest during the second measurement in most cases; no trend was observed for the TPT

  20. Isokinetic assessment of the flexor-extensor balance of the knee in athletes with total rupture of the anterior cruciate ligament Avaliação isocinética do equilíbrio flexo-extensor do joelho nos atletas com ruptura total do ligamento cruzado anterior

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    Antonio Sérgio A. P. Terreri

    1999-04-01

    Full Text Available The purpose of this study was to assess the flexor-extensor group of muscles of the knee in young athletes diagnosed with a total rupture of the anterior cruciate ligament (ACL. Eighteen knees of 18 athletes (14 men and 4 women with an average age of 21.6 years (range 16-32 years were assessed with a Cybex 6000 model isokinetic apparatus. The average interval between occurrence of the injury and assessment was 10.2 months (range 2 - 48 months. There was an associated meniscal injury in eight of the knees. Athletes with any other kind of associated injury, limitation, or blockage of the movement of the joint, significant pain during the exam, or interval between injury and exam of less than two months were excluded from the study. The parameters studied were the peak torque-velocity and flexor-extensor relationships at the constant angular velocities of 60°/sec and 240°/sec. Previous warming-up was done by means of an ergometric bicycle and adaptation with 3 submaximal repetitions. The contra-lateral side, which presented no injury, was used as control. Peak torque (PT at the constant velocity of 60°/sec was greater than that at 240°/sec for knees with and without injuries. However, there was no significant difference between the injured and uninjured sides at 60°/sec or at 240°/sec. The average value for the flexor-extensor relationship at 60°/sec on the injured was 60% (( 6, compared to 57% (( 10 on the contra-lateral side. At 240°/sec, the average value was 75% ((10 on the injured side, and 65% ((12 on the contra-lateral side. In conclusion, despite the complete rupture of the ACL of one knee, the average values for the flexor-extensor relationship were similar on the injured and uninjured sides at the velocity of 60°/sec. As the velocity increased, an increase in the values for the flexor-extensor relationship of the knee also occurred, indicating a tendency of the performance of the flexor muscle group to approach that of the

  1. Anterior knee pain: an update of physical therapy.

    Science.gov (United States)

    Werner, Suzanne

    2014-10-01

    Anterior knee pain is one of the most common knee problems in physically active individuals. The reason for anterior knee pain has been suggested to be multifactorial with patella abnormalities or extensor mechanism disorder leading to patellar malalignment during flexion and extension of the knee joint. Some patients complain mostly of non-specific knee pain, while others report patellar instability problems. The patients present with a variety of symptoms and clinical findings, meaning that a thorough clinical examination is the key for optimal treatment. Weakness of the quadriceps muscle, especially during eccentric contractions, is usually present in the majority of anterior knee pain patients. However, irrespective of whether pain or instability is the major problem, hypotrophy and reduced activity of the vastus medialis are often found, which result in an imbalance between vastus medialis and vastus lateralis. This imbalance needs to be corrected before quadriceps exercises are started. The non-operative rehabilitation protocol should be divided into different phases based on the patient's progress. The goal of the first phase is to reduce pain and swelling, improve the balance between vastus medialis and vastus lateralis, restore normal gait, and decrease loading of the patello-femoral joint. The second phase should include improvement of postural control and coordination of the lower extremity, increase of quadriceps strength and when needed hip muscle strength, and restore good knee function. The patient should be encouraged to return to or to start with a suitable regular physical exercise. Therefore, the third phase should include functional exercises. Towards the end of the treatment, single-leg functional tests and functional knee scores should be used for evaluating clinical outcome. A non-operative treatment of patients with anterior knee pain should be tried for at least 3 months before considering other treatment options.

  2. Dispositivo de proteção após reparação das rupturas do mecanismo extensor do joelho Protection device on the repair of ruptures of knee extensor mechanism

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    Carlos Francisco Arguello Frutos

    2009-02-01

    Full Text Available OBJETIVO: Avaliar os resultados obtidos com a realização da técnica de dispositivo de proteção nos pacientes submetidos à osteossíntese ou sutura de lesões do mecanismo extensor. MÉTODOS: Foram avaliados 18 prontuários de pacientes que sofreram lesões traumáticas do aparelho extensor interessando a região entre a tuberosidade anterior da tíbia (TAT e o ápice da patela submetido à técnica de dispositivo de proteção. A idade variou de 22 a 69 anos, com média de 44 anos. Houve predomínio do sexo masculino em 67 % dos casos. O local mais acometido em 83 % dos casos foi o 1/3 apical da patela. Foi elaborado um protocolo para coleta dos dados informativos relacionando os pacientes e a sua evolução obtida em seus prontuários. RESULTADOS: Observamos a consolidação da fratura de patela em todos os 17 pacientes, e a cicatrização do ligamento patelar num único caso. A dor esteve presente em quatro pacientes, sendo que não observamos nenhuma outra complicação relacionada com a técnica cirúrgica. CONCLUSÃO: O dispositivo de proteção é eficiente quando aplicado no tratamento operatório das lesões que se localizam entre o ápice da patela e a TAT propiciando movimentação ativa e passiva no pós-operatório imediato.OBJECTIVE: To evaluate results obtained using the protection device technique for osteosintesis or suture of extensor mechanism lesions. MATERIAL AND METHODS: The authors reviewed 18 charts of patients submitted to protection device technique due to traumatic lesion of extensor mechanism that had occurred between the anterior tibial tuberosity and the apical portion of patella. Age ranged from 22 to 69 years, with a mean of 44 years. Male patients prevailed, with 67% of the cases. The most affected spot was, in 83% of the cases, the apical distal third. A protocol was created to collect data, listing the patients and the clinical history from their medical records. RESULTS: The authors observed consolidation

  3. Core stability, knee muscle strength, and anterior translation are correlated with postural stability in anterior cruciate ligament-reconstructed patients.

    Science.gov (United States)

    Cinar-Medeni, Ozge; Baltaci, Gul; Bayramlar, Kezban; Yanmis, Ibrahim

    2015-04-01

    The purpose of this study was to investigate the relationship of postural stability and lower extremity performance with core stability, knee laxity, and muscle strength in patients with anterior cruciate ligament reconstruction. Twenty-eight anterior cruciate ligament-reconstructed subjects were included in the study. Anterior knee laxity tests, isokinetic knee muscle strength tests, and core stability tests were performed. Single-limb postural stability was assessed in both eyes-open and eyes-closed positions on a static surface and an eyes-open condition on a foam surface. A single-legged hop test was performed to assess lower extremity performance. To detect differences between the operated and healthy leg, a Mann-Whitney U test was performed, and a correlation analysis was performed using the Spearman correlation coefficient. Knee muscle strength and laxity were different between the operated and healthy legs (P stability scores correlated with core stability tests (P core stability, decreased knee muscle strength, and increased knee laxity correlated with single-limb postural stability. Better hop performance was demonstrated with better knee flexor and extensor muscle strength and was independent from core stability.

  4. The effect of the training with the different combinations of frequency and peak-to-peak vibration displacement of whole-body vibration on the strength of knee flexors and extensors

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    M Stania

    2017-01-01

    Full Text Available Whole-body vibration training has become a popular method used in sports and physiotherapy. The study aimed to evaluate the effect of different vibration frequency and peak-to-peak displacement combinations on men knee flexors and extensors strength in isokinetic conditions. The sample consisted of 49 male subjects randomly allocated to seven comparative groups, six of which exercised on a vibration platform with parameters set individually for the groups. The experimental groups were exposed to vibrations 3 times a week for 4 weeks. The pre- and post- isokinetic strength tests, with the angular velocities of 240°/s and 30°/s, were recorded prior to and 2 days after the training. After 4 weeks of whole-body vibration training, a significant increase was noted regarding the mean values of peak torque, average peak torque and total work for knee flexors at high angular velocity in Groups I (60 Hz/ 4 mm and V (40 Hz/ 2 mm (p<0.05. The mean percentage values of post-training changes to study parameters suggest that the training had the most beneficial effect in Groups I (60 Hz/4 mm and IV (60 Hz/2 mm (p<0.05. Whole-body vibrations during static exercise beneficially affected knee flexor strength profile in young men at high angular velocity. The combinations of 60 Hz/4 mm seem to have the most advantageous effects on muscle strength parameters.

  5. TRUNK LEAN DURING A SINGLE-LEG SQUAT IS ASSOCIATED WITH TRUNK LEAN DURING PITCHING.

    Science.gov (United States)

    Plummer, Hillary A; Oliver, Gretchen D; Powers, Christopher M; Michener, Lori A

    2018-02-01

    Impaired trunk motion during pitching may be a risk factor for upper extremity injuries. Specifically, increased forces about the shoulder and elbow have been observed in pitchers with excessive contralateral trunk lean during pitching. Because of the difficulty in identifying abnormal trunk motions during a high-speed task such as pitching, a clinical screening test is needed to identify pitchers who have impaired trunk motion during pitching. The purpose of this study was to determine the relationship between the degree of lateral trunk lean during the single-leg squat and amount of trunk lean during pitching and if trunk lean during pitching can be predicted from lean during the single-leg squat. Controlled Laboratory Study; Cross-sectional. Seventy-three young baseball pitchers (11.4 ± 1.7 years; 156.3 ± 11.9 cm; 50.5 ± 8.8 kg) participated. An electromagnetic tracking system was used to obtain trunk kinematic data during a single-leg squat task (lead leg) and at maximum shoulder external rotation of a fastball pitch. Pearson correlation coefficients for trunk lean during the single-leg squat and pitching were calculated. A linear regression analysis was performed to determine if trunk lean during pitching can be predicted from lean during the single-leg squat. There was a positive correlation between trunk lean during the single-leg squat and trunk lean during pitching (r = 0.53; plean during the single-leg squat predicted the amount of lateral trunk lean during pitching (R 2 = 0.28; p lean during an SLS and pitching. Trunk lean during the single-leg squat explained 28% of the variance in trunk lean during pitching. Diagnosis, level 3.

  6. Single-leg drop landing motor control strategies following acute ankle sprain injury.

    Science.gov (United States)

    Doherty, C; Bleakley, C; Hertel, J; Caulfield, B; Ryan, J; Delahunt, E

    2015-08-01

    No research currently exists investigating the effect of acute injury on single-limb landing strategies. The aim of the current study was to analyze the coordination strategies of participants in the acute phase of lateral ankle sprain (LAS) injury. Thirty-seven participants with acute, first-time LAS and 19 uninjured participants completed a single-leg drop landing task on both limbs. Three-dimensional kinematic (angular displacement) and sagittal plane kinetic (moment-of-force) data were acquired for the joints of the lower extremity from 200 ms pre-initial contact (IC) to 200 ms post-IC. The peak magnitude of the vertical component of the ground reaction force (GRF) was also computed. Injured participants displayed a bilateral increase in hip flexion, with altered transverse plane kinematic profiles at the knee and ankle for both limbs (P < 0.05). This coincided with a reduction in the net-supporting flexor moment of the lower extremity (P < 0.05) and magnitude of the peak vertical GRF for the injured limb (21.82 ± 2.44 N/kg vs 24.09 ± 2.77 N/kg; P = 0.013) in injured participants compared to control participants. These results demonstrate that compensatory movement strategies are utilized by participants with acute LAS to successfully reduce the impact forces of landing. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Asymmetrical stabilization and mobilization exploited during static single leg stance and goal directed kicking.

    Science.gov (United States)

    King, Adam C; Wang, Zheng

    2017-08-01

    The motor control properties of the right and left legs are dependent on the stabilization and mobilization features of the motor tasks. The current investigation examined the right and left leg control differences - interlateral asymmetries - during static single leg stance and dynamic goal directed kicking with an emphasis of the asymmetrical stabilization and mobilization components of movements. Ten young, healthy, right-leg preferred individuals with minimal kicking experience completed both tests on each limb. During static single leg stance, participants were requested to stand as still as possible with one leg in contact with a force platform. Interlateral asymmetries of the standing leg were quantified using postural variability measures of the center of pressure (COP) standard deviation in the anterior-posterior (SD-COP AP ) and medial-lateral (SD-COP ML ) directions, resultant COP length and velocity, and 95% COP elliptical area. During dynamic goal directed kicking, participants stood on two adjacent force platforms in a side-by-side foot position and kicked a soccer ball toward three different directions as soon as they received an auditory cue of kicking. Three targets were located -30°, 0° or 30° in front and 3.05 m away from the participants' midline. Participants kicked the ball toward the targets with each of their feet. The vertical ground reaction force (vGRF) of the kicking leg was used to define the preparation (from above two standard deviations of vGRF baseline to toe-off) and swing (from toe-off to toe-return) phases of dynamic kicking. To determine the presence of interlateral asymmetries during dynamic kicking, the magnitude and timing of the anticipatory postural adjustments (APA) during the preparation phase of kicking were quantified using the lateral net COP (COPnet-ML) time series derived from both force platforms. Postural variability measures of the support leg and the kinematic joint range of motion (JROM) trajectories of the

  8. Quadriceps Strength in Patients With Isolated Cartilage Defects of the Knee: Results of Isokinetic Strength Measurements and Their Correlation With Clinical and Functional Results.

    Science.gov (United States)

    Hirschmüller, Anja; Andres, Tasja; Schoch, Wolfgang; Baur, Heiner; Konstantinidis, Lukas; Südkamp, Norbert P; Niemeyer, Philipp

    2017-05-01

    Recent studies have found a significant deficit of maximum quadriceps strength after autologous chondrocyte implantation (ACI) of the knee. However, it is unclear whether muscular strength deficits in patients with cartilage damage exist prior to operative treatment. To isokinetically test maximum quadriceps muscle strength and quantify the impact of possible strength deficits on functional and clinical test results. Cross-sectional study; Level of evidence, 3. To identify clinically relevant muscular strength deficits, 24 patients (5 females, 19 males; mean age, 34.5 years; body mass index, 25.9 kg/m 2 ) with isolated cartilage defects (mean onset, 5.05 years; SD, 7.8 years) in the knee joint underwent isokinetic strength measurements. Maximal quadriceps strength was recorded in 3 different testing modes: pure concentric contraction (flexors and extensors alternating work; con1), concentric-eccentric (only the extensors work concentrically and eccentrically; con2), and eccentric contraction in the alternating mode (ecc). Results were compared for functional performance (single-leg hop test), pain scales (visual analog scale [VAS], numeric rating scale [NRS]), self-reported questionnaires (International Knee Documentation Committee [IKDC], Knee Injury and Osteoarthritis Outcome Scale [KOOS]), and defect size (cm 2 ). Compared with the uninjured leg, significantly lower quadriceps strength was detected in the injured leg in all isokinetic working modes (con1 difference, 27.76 N·m [SD 17.47; P = .003]; con2 difference, 21.45 N·m [SD, 18.45; P =.025]; ecc difference, 29.48 N·m [SD, 21.51; P = .001]), with the largest deficits found for eccentric muscle performance. Moderate negative correlations were observed for the subjective pain scales NRS and VAS. The results of the IKDC and KOOS questionnaires showed low, nonsignificant correlations with findings in the isokinetic measurement. Moreover, defect sizes (mean, 3.13 cm 2 ) were of no importance regarding the

  9. Neuromuscular Control Mechanisms During Single-Leg Jump Landing in Subacute Ankle Sprain Patients: A Case Control Study.

    Science.gov (United States)

    Allet, Lara; Zumstein, Franziska; Eichelberger, Patric; Armand, Stéphane; Punt, Ilona M

    2017-03-01

    Optimal neuromuscular control mechanisms are essential for preparing, maintaining, and restoring functional joint stability during jump landing and to prevent ankle injuries. In subacute ankle sprain patients, neither muscle activity nor kinematics during jump landing has previously been assessed. To compare neuromuscular control mechanisms and kinematics between subacute ankle sprain patients and healthy persons before and during the initial contact phase of a 25-cm single-leg jump. Case-control study. University hospital. Fifteen patients with grade I or II acute ankle sprains were followed up after 4 weeks of conservative management not involving physical therapy. Subjects performed alternately 3 single-leg forward jumps of 25 cm (toe-to-heel distance) barefoot. Their results were compared with the data of 15 healthy subjects. Electromyographic (EMG) activity of the musculus (m.) gastrocnemius lateralis, m. tibialis anterior, and m. peroneus longus as well as kinematics for ankle, knee, and hip joint were recorded for pre-initial contact (IC) phase, post-initial contact phase, and reflex-induced phase. The results showed that EMG activity of the 3 muscles did not differ between ankle sprain patients (n = 15) and healthy persons (n = 15) for any of the analyzed time intervals (all P > .05). However, during the pre-IC phase, ankle sprain patients presented less plantar flexion, as well as during the post-IC phase after jump landing, compared to healthy persons (P ankle joint can lead to neuromuscular control mechanism disturbances through which functional instability might arise. III. Copyright © 2017 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  10. Effects of fatigue on lower limb, pelvis and trunk kinematics and lower limb muscle activity during single-leg landing after anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Lessi, Giovanna Camparis; Serrão, Fábio Viadanna

    2017-08-01

    Because there are no studies that have evaluated the effects of fatigue on the kinematics of the trunk and pelvis or on muscle activation in subjects with ACL reconstruction, the aim of this study was to evaluate the effects of fatigue on the lower limb, pelvis and trunk kinematics and lower limb muscle activation in subjects with ACL reconstruction during a single-leg landing compared to a healthy control group. The participants included 20 subjects with ACL reconstruction (ACL reconstruction group-ACLRG) and 20 healthy subjects (control group-CG) who were aged between 18 and 35 years. Kinematic and electromyographic analyses were performed during a single-leg landing before and after fatigue. The fatigue protocol included a series of 10 squats, two vertical jumps, and 20 steps. The effects of fatigue were increased peak trunk flexion and increased activation of the vastus lateralis, biceps femoris (BF) and gluteus maximus (GMax) during the landing phase. After the fatigue protocol, an increase in peak trunk flexion and activation of the GMax and BF were observed, most likely as a strategy to reduce the load on the ACL. ACL injury prevention programs should include strength and endurance exercises for the hip and trunk extensor muscles so that they can efficiently control trunk flexion during landing. Prospective comparative study, Level II.

  11. Extensor Tendon Injuries

    Science.gov (United States)

    ... Media Find a Hand Surgeon Home Anatomy Extensor Tendon Injuries Email to a friend * required fields From * ... to straighten one or more joints. Common Extensor Tendon Injuries Mallet Finger refers to a drooping end- ...

  12. Impacto do alongamento estático no ganho de força muscular dos extensores de joelho em idosas da comunidade após um programa de treinamento Impact of static stretching on the gain in knee-extensor strength of community-dwelling older women after a training program

    Directory of Open Access Journals (Sweden)

    Lygia P. Lustosa

    2010-12-01

    prior to strengthening exercises on muscle strength gain. OBJECTIVE: To verify the impact of static stretching on the gain in knee-extensor strength of community-dwelling elderly women after a training program. METHODS: This was a quasi-experimental study that included a ten-week knee-extensor strengthening program and a final assessment of 12 community-dwelling elderly women divided into two groups: group SE - strengthening exercises with prior static stretching in all sessions, mean age 73.8 (±5.36 years; and group E - same strengthening exercises as SE without prior stretching, mean age 72.14 (±5.43 years. To measure knee-extensor strength gains, we used the isokinetic dynamometer Biodex System 3 Pro, in concentric mode at angular velocities of 60º and 180º/s, and for statistical analysis we used the difference between pre- and post-intervention means of work adjusted by body weight. RESULTS: The data showed normality in the Shapiro-Wilk test (p>0.266. When comparing the differences between the pre- and post-intervention means using the t test for independent samples, there was no significant difference in any of the limbs at the velocities evaluated (p>0.383. CONCLUSION: Previous static stretching did not interfere in muscle strength gain following a ten-week muscle strengthening program in the population studied. Article registered in the ISRCTN register under number ISRCTN62824599.

  13. Lower extremity muscle activation onset times during the transition from double-leg stance to single-leg stance in anterior cruciate ligament reconstructed subjects.

    Science.gov (United States)

    Dingenen, Bart; Janssens, Luc; Claes, Steven; Bellemans, Johan; Staes, Filip F

    2016-06-01

    Previous studies mainly focused on muscles at the operated knee after anterior cruciate ligament reconstruction, less on muscles around other joints of the operated and non-operated leg. The aim of this study was to investigate muscle activation onset times during the transition from double-leg stance to single-leg stance in anterior cruciate ligament reconstructed subjects. Lower extremity muscle activation onset times of both legs of 20 fully returned to sport anterior cruciate ligament reconstructed subjects and 20 non-injured control subjects were measured during the transition from double-leg stance to single-leg stance in eyes open and eyes closed conditions. Analysis of covariance (ANCOVA) was used to evaluate differences between groups and differences between legs within both groups, while controlling for peak center of pressure velocity. Significantly delayed muscle activation onset times were found in the anterior cruciate ligament reconstructed group compared to the control group for gluteus maximus, gluteus medius, vastus medialis obliquus, medial hamstrings, lateral hamstrings and gastrocnemius in both eyes open and eyes closed conditions (Panterior cruciate ligament reconstructed group, no significant different muscle activation onset times were found between the operated and non-operated leg (P>.05). Despite completion of rehabilitation and full return to sport, the anterior cruciate ligament reconstructed group showed neuromuscular control deficits that were not limited to the operated knee joint. Clinicians should focus on relearning multi-segmental anticipatory neuromuscular control strategies after anterior cruciate ligament reconstruction. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Active and Inactive Leg Hemodynamics during Sequential Single-Leg Interval Cycling.

    Science.gov (United States)

    Gordon, Nicole; Abbiss, Chris R; Ihsan, Mohammed; Maiorana, Andrew J; Peiffer, Jeremiah J

    2018-01-11

    Leg order during sequential single-leg cycling (i.e. exercising both legs independently within a single session) may affect local muscular responses potentially influencing adaptations. This study examined the cardiovascular and skeletal muscle hemodynamic responses during double-leg and sequential single-leg cycling. Ten young healthy adults (28 ± 6 y) completed six 1-min double-leg intervals interspersed with one minute of passive recovery and, on a separate occasion, 12 (six with one leg followed by six with the other leg) 1-min single-leg intervals interspersed with one minute of passive recovery. Oxygen consumption, heart rate, blood pressure, muscle oxygenation, muscle blood volume and power output were measured throughout each session. Oxygen consumption, heart rate and power output were not different between sets of single-leg intervals but the average of both sets was lower than the double-leg intervals. Mean arterial pressure was higher during double-leg compared with sequential single-leg intervals (115 ± 9 mmHg vs. 104 ± 9 mmHg; p<0.05) and higher during the initial compared with second set of single-leg intervals (108 ± 10 mmHg vs. 101 ± 10 mmHg; p<0.05). The increase in muscle blood volume from baseline was similar between the active single-leg and double-leg (267 ± 150 μM[BULLET OPERATOR]cm vs. 214 ± 169 μM[BULLET OPERATOR]cm; p=0.26). The pattern of change in muscle blood volume from the initial to second set of intervals was significantly different (p<0.05) when the leg was active in the initial (-52.3 ± 111.6%) compared with second set (65.1 ± 152.9%). These data indicate that the order in which each leg performs sequential single-leg cycling influences the local hemodynamic responses, with the inactive muscle influencing the stimulus experienced by the contralateral leg.

  15. The predictive validity of a single leg bridge test for hamstring injuries in Australian Rules Football Players.

    Science.gov (United States)

    Freckleton, Grant; Cook, Jill; Pizzari, Tania

    2014-04-01

    Hamstring muscle strain injuries (HMSI) are the greatest injury problem in kicking sports such as Australian Rules Football. Reduced hamstring muscle strength is commonly perceived to be a risk factor for hamstring injury; however, evidence is inconclusive. Testing hamstring strength with the hip and knee at functional angles and assessing endurance parameters may be more relevant for examining the risk of hamstring injury. The primary aim of this prospective study was to examine if reduced hamstring muscle strength assessed with the single leg hamstring bridge (SLHB) was a risk factor for hamstring injury. Hamstring muscle strength of 482 amateur and semielite players from 16 football clubs, mean age 20.7 (range 16-34 years), was tested during the 2011 preseason. Players were then monitored throughout the 2011 playing season for HMSI. A total of 28 hamstring injuries, 16 right and 12 left, were recorded. Players who sustained a right HMSI during the season had a significantly lower mean right SLHB score (p=0.029), were older (p=0.002) and were more likely to have sustained a past right hamstring injury (p=0.02) or right knee injury (p=0.035). For left-sided hamstring injury, the injured group was more likely to be left leg dominant (p=0.001), older athletes (p=0.002) and there was a trend towards a history of left hamstring injury (p=0.07). This study demonstrated a significant deficit in preseason SLHB scores on the right leg of players that subsequently sustained a right-sided hamstring injury. Age, previous knee injury and a history of hamstring injury were other risk factors supported in this study. Low hamstring strength appears to be a risk factor for hamstring injury; however, due to the confounding variables and low injury rate in this study, further studies are required.

  16. The effects of a muscle resistance program on the functional capacity, knee extensor muscle strength and plasma levels of IL-6 and TNF-α in pre-frail elderly women: a randomized crossover clinical trial - a study protocol

    Directory of Open Access Journals (Sweden)

    Dias João MD

    2010-07-01

    Full Text Available Abstract Background With the increase in the elderly population, a growing number of chronic degenerative diseases and a greater dependency on caregivers have been observed. Elderly persons in states of frailty remain more susceptible to significant health complications. There is evidence of an inverse relationship between plasma levels of inflammatory mediators and levels of functionality and muscle strength, suggesting that muscle-strengthening measures can aid in inflammatory conditions. The purpose of this study will be verified the effect of a muscle-strengthening program with load during a ten-week period in pre-frail elderly women with attention to the following outcomes: (1 plasma levels of interleukin-6 (IL-6 and tumor necrosis factor alpha (TNF-α, (2 functional capacity and (3 knee extensor muscle strength. Methods/Design The study design is a randomized crossover clinical trial evaluating 26 elderly women (regardless of their race and/or social condition who are community residents, older than 65, and classified as pre-frail according to the criteria previously described by Fried et al. (2004. All subjects will be assessed using the Timed up and go and 10-Meter Walk Test functional tests. The plasma levels of IL-6 and TNF-α will be assessed by ELISA (enzyme-linked immunosorbent assay with high sensitivity kits (Quantikine®HS, R&D Systems Minneapolis, MN, U.S.. Knee extensor muscle strength will be assessed using the Byodex System 3 Pro® isokinetic dynamometer at angular speeds of 60 and 180°/s. The intervention will consist of strengthening exercises of the lower extremities at 50 to 70% of 1RM (maximal resistance three times per week for ten weeks. The volunteers will be randomized into two groups: group E, the intervention group, and group C, the control group that did not initiate any new activities during the initial study period (ten weeks. After the initial period, group C will begin the intervention and group E will

  17. Decrements in knee extensor and flexor strength are associated with performance fatigue during simulated basketball game-play in adolescent, male players.

    Science.gov (United States)

    Scanlan, Aaron T; Fox, Jordan L; Borges, Nattai R; Delextrat, Anne; Spiteri, Tania; Dalbo, Vincent J; Stanton, Robert; Kean, Crystal O

    2018-04-01

    This study quantified lower-limb strength decrements and assessed the relationships between strength decrements and performance fatigue during simulated basketball. Ten adolescent, male basketball players completed a circuit-based, basketball simulation. Sprint and jump performance were assessed during each circuit, with knee flexion and extension peak concentric torques measured at baseline, half-time, and full-time. Decrement scores were calculated for all measures. Mean knee flexor strength decrement was significantly (P jump fatigue during the entire game. Lower-limb strength decrements may exert an important influence on performance fatigue during basketball activity in adolescent, male players. Consequently, training plans should aim to mitigate lower-limb fatigue to optimise sprint and jump performance during game-play.

  18. The role of robust optimization in single-leg airline revenue management

    NARCIS (Netherlands)

    Birbil, S.I.; Frenk, J.B.G.; Gromicho Dos Santos, J.A.; Zhang, S.

    2009-01-01

    In this paper, we introduce robust versions of the classical static and dynamic single-leg seat allocation models. These robust models take into account the inaccurate estimates of the underlying probability distributions. As observed by simulation experiments, it turns out that for these robust

  19. An integrated approach to single-leg airline revenue management: The role of robust optimization

    NARCIS (Netherlands)

    S.I. Birbil (Ilker); J.B.G. Frenk (Hans); J.A.S. Gromicho (Joaquim); S. Zhang (Shuzhong)

    2006-01-01

    textabstractIn this paper we introduce robust versions of the classical static and dynamic single leg seat allocation models as analyzed by Wollmer, and Lautenbacher and Stidham, respectively. These robust models take into account the inaccurate estimates of the underlying probability distributions.

  20. An Integrated Approach to Single-Leg Airline Revenue Management: The Role of Robust Optimization

    NARCIS (Netherlands)

    S.I. Birbil (Ilker); J.B.G. Frenk (Hans); J.A.S. Gromicho (Joaquim); S. Zhang (Shuzhong)

    2006-01-01

    textabstractIn this paper we introduce robust versions of the classical static and dynamic single leg seat allocation models as analyzed by Wollmer, and Lautenbacher and Stidham, respectively. These robust models take into account the inaccurate estimates of the underlying probability distributions.

  1. Modeling and optimization of the single-leg multi-fare class ...

    African Journals Online (AJOL)

    This paper presents a static overbooking model for a single-leg multi-fare class flight. A realistic distribution of no-show data in modeling the cost function was considered using data collected from the Ethiopian airlines. The overbooking model developed considers the interaction (i.e. the transfer of an extra passenger in a ...

  2. Impairment of dynamic single-leg balance performance in individuals with hip chondropathy.

    Science.gov (United States)

    Hatton, Anna L; Kemp, Joanne L; Brauer, Sandra G; Clark, Ross A; Crossley, Kay M

    2014-05-01

    Impaired balance control has been reported in the elderly with hip osteoarthritis, yet this relationship has not been explored in young adults with hip chondropathy. This study aimed to determine whether people with hip chondropathy demonstrated impaired balance ability during a dynamic single-leg squat with eyes open (SquatEO) and a single-leg standing task with eyes closed (StandEC) and whether hip range of motion (ROM) and hip muscle strength were correlated with balance measures in adults with hip chondropathy. Sixty-three adults with hip chondropathy and 60 controls performed 2 tasks: SquatEO and StandEC while standing on a Nintendo Wii Balance Board. Center of pressure (COP) movement in mediolateral and anteroposterior directions was extracted. Hip ROM and muscle strength were measured with an inclinometer and dynamometer. Data were analyzed using an analysis of covariance and stepwise multiple regression model. During SquatEO, greater COP mediolateral range (P = 0.023) and anteroposterior SD (P = 0.043) were observed in those with hip chondropathy compared to controls. No significant between-group differences were observed for StandEC. Hip external rotation ROM was significantly associated with mediolateral range during SquatEO. Dynamic single-leg balance squat performance is reduced in people with hip chondropathy compared to healthy adults, but static single-leg standing balance is not. This may be reflective of reduced control of dynamic movements. Those with greater hip joint external rotation ROM appear to have worse single-leg squat balance performance. Further investigation into balance deficits associated with hip disease is necessary to establish early identification strategies and a tailored approach to rehabilitation. Copyright © 2014 by the American College of Rheumatology.

  3. Comparative Evaluation of Core and Knee Extensor Mechanism Muscle Activation Patterns in a Stair Stepping Task in Healthy Controls and Patellofemoral Pain Patients

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    Alireza Motealleh

    2014-12-01

    Full Text Available Background: Patellofemoral pain (PFP is a common affliction and complex clinical entity. Deficit in neuromotor control of the core may be a remote contributing factor to the development of PFPS. Comparative evaluation of core and extensor mechanism muscle activation patterns between healthy group and patients involved by patellofemoral pain syndrome (PFPS in a stair stepping task is the aim of this study. Methods: In this non-randomized interventional study fifteen males with PFPS and fifteen asymptomatic controls participated. Electromyographic (EMG activity of Vastusmedialisobliquus (VMO, Vastuslateralis (VL, Gluteus medius (GMED, Gluteus Maximus (GMAX, Internal oblique (IO and Erector spinae (ES were recorded and EMG onsets were assessed in both stepping up (SU and down (SD. The time of foot contact determined by a foot switch. Results: During SU: Onset times of all muscles except, VL and ES in the controls were significantly less than PFPS group (P<0.05. In PFPS group the temporal sequence of ES, VL and VMO were different from control groups. During SD: Onset times of all muscles except, GMAX and ES in the control group were significantly less than PFP group (P<0.05. The sequence of muscle activity in both healthy and PFP groups were the same. Conclusion: Our findings are in line with previous researches about the effects of core on function and control of lower extremity. Activation patterns of core and vasti muscles are different between control and PFPS group during stair stepping task. Designing exercises to correct inappropriate timing of core muscles may have a role in management of PFPS and it needs more future researches.

  4. An Integrated Approach to Single-Leg Airline Revenue Management: The Role of Robust Optimization

    OpenAIRE

    Birbil, Ilker; Frenk, Hans; Gromicho, Joaquim; Zhang, Shuzhong

    2006-01-01

    textabstractIn this paper we introduce robust versions of the classical static and dynamic single leg seat allocation models as analyzed by Wollmer, and Lautenbacher and Stidham, respectively. These robust models take into account the inaccurate estimates of the underlying probability distributions. As observed by simulation experiments it turns out that for these robust versions the variability compared to their classical counter parts is considerably reduced with a negligible decrease of av...

  5. Differences in take-off leg kinetics between horizontal and vertical single-leg rebound jumps.

    Science.gov (United States)

    Kariyama, Yasushi; Hobara, Hiroaki; Zushi, Koji

    2017-06-01

    This study aimed to clarify the differences between the horizontal single-leg rebound jump (HJ) and vertical single-leg rebound jump (VJ) in terms of three-dimensional joint kinetics for the take-off leg, while focusing on frontal and transverse plane movements. Eleven male track and field athletes performed HJ and VJ. Kinematic and kinetic data were calculated using data recorded with a motion capture system and force platforms. The hip abduction torque, trunk lateral flexion torque (flexion for the swing-leg side), hip external and internal torque, trunk rotational torque, and the powers associated with these torques were larger when performing HJ because of resistance to the impact ground reaction force and because of pelvic and posture control. Pelvic rotation was noted in HJ, and this was controlled not only by the hip and trunk joint torque from the transverse plane but also by the hip abduction torque. Therefore, hip and trunk joint kinetics in the frontal and transverse plane play an important role in a single-leg jump, regardless of the jumping direction, and may also play a more important role in HJ than in VJ.

  6. Análise da resposta da freqüência cardíaca durante a realização de exercício isocinético excêntrico de grupamento extensor de joelho Analysis of heart rate response during eccentric isokinetic exercise of knee extensor muscle group

    Directory of Open Access Journals (Sweden)

    CA Malfatti

    2006-01-01

    Full Text Available Objetivo: Investigar a magnitude da resposta da freqüência cardíaca durante o exercício isocinético excêntrico do grupamento extensor do joelho, em diferentes velocidades angulares. Materiais e Métodos: Dez voluntários jovens, sadios e ativos foram submetidos a contração excêntrica máxima do grupo extensor do joelho dominante. Foi utilizado um dinamômetro isocinético, nas velocidades de 30º/s, 60º/s e 120º/s, ordenadas aleatoriamente. A FC foi obtida batimento a batimento, na derivação eletrocardiográfica MC5 modificada, durante 60s pré-exercício, durante o tempo de contração, sendo cinco repetições para cada velocidade, e por 120s após o esforço. Foram calculadas: FC média dos 60s pré-exercício, FC pico atingida ao final do esforço, e variação da FC (DFC, além dos valores do pico de torque. Também foram comparados valores da FC média dos 6 minutos pré-exercício com os 6 minutos de recuperação. Os resultados foram comparados pelo teste de Friedman com post hoc de Dunn. O nível de significância estabelecido foi de 5%. Resultados: Não foram observadas diferenças estatisticamente significantes entre os valores medianos da FC de repouso (68bpm para 30º/s e 60º/s, 70bpm para 120º/s, FC pico (107bpm para 30º/s, 103 em 60º/s e 100bpm em 120º/s e DFC (37bpm para 30º/s, 35bpmem 60º/s e 27bpm para 120ºs, além do pico de torque (209,5N/m para 30º/s, 217,2N/m em 60º/s e 210,6N/m para 120º/s. A mediana dos valores de FC anteriores ao esforço foi semelhante aos de recuperação (67bpm. Conclusão:A magnitude de resposta da FC foi semelhante, durante atividade muscular excêntrica, indicando uma mesma sobrecarga cardíaca, independente da velocidade angular realizada.Objective: To investigate heart rate response magnitudes during eccentric isokinetic exercise of the knee extensor muscles, at different angular velocities. Method: Ten healthy and active young volunteers underwent maximum eccentric

  7. Assessment of muscle endurance of the knee extensor muscles in adolescents with spastic cerebral palsy using a submaximal repetitions-to-fatigue protocol.

    Science.gov (United States)

    Eken, Maaike M; Dallmeijer, Annet J; Doorenbosch, Caroline A; Dekkers, Hurnet; Becher, Jules G; Houdijk, Han

    2014-10-01

    To compare muscle endurance in adolescents with spastic cerebral palsy (CP) with typically developing (TD) peers using a submaximal repetitions-to-fatigue (RTF) protocol. Cross sectional. Human motion laboratory. Adolescents with spastic CP (n=16; Gross Motor Function Classification System levels I or II) and TD adolescents (n=18) within the age range of 12 to 19 years old. Not applicable. Each participant performed 3 RTF tests at different submaximal loads, ranging from 50% to 90% of their maximal voluntary knee extension torque. The relation between the number of repetitions (repetition maximum [RM]) and imposed submaximal relative (percent of maximal voluntary torque [%MVT]) and absolute (Nm/kg) torque was quantified. To compare adolescents with CP with TD adolescents, a mixed linear model was used to construct load endurance curves. Surface electromyography of quadriceps muscles was measured to assess changes in normalized amplitude and median frequency (MF) as physiological indicators of muscle fatigue. Adolescents with CP showed a larger decrease in %MVT per RM than TD adolescents (Padolescents showed substantial higher absolute (Nm/kg) load endurance curves than adolescents with CP (PAdolescents with CP show slightly lower muscle endurance compared with TD adolescents on a submaximal RTF protocol, which is in contrast with earlier findings in a maximal voluntary fatigue protocol. Accordingly, adolescents with CP have a reduced capacity to endure activities at similar relative loads compared with TD adolescents. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  8. Asymmetry between the Dominant and Non-Dominant Legs in the Kinematics of the Lower Extremities during a Running Single Leg Jump in Collegiate Basketball Players.

    Science.gov (United States)

    Sugiyama, Takashi; Kameda, Mai; Kageyama, Masahiro; Kiba, Kazufusa; Kanehisa, Hiroaki; Maeda, Akira

    2014-12-01

    The present study aimed to clarify the asymmetry between the dominant (DL) and non-dominant takeoff legs (NDL) in terms of lower limb behavior during running single leg jumps (RSJ) in collegiate male basketball players in relation to that of the jump height. Twenty-seven players performed maximal RSJ with a 6 m approach. Three-dimensional kinematics data during RSJ was collected using a 12 Raptor camera infrared motion analysis system (MAC 3D system) at a sampling frequency of 500 Hz. The symmetry index in the jump heights and the kinematics variables were calculated as {2 × (DL - NDL) / (DL + NDL)} × 100. The run-up velocity was similar between the two legs, but the jump height was significantly higher in the DL than in the NDL. During the takeoff phase, the joint angles of the ankle and knee were significantly larger in the DL than the NDL. In addition, the contact time for the DL was significantly shorter than that for the NDL. The symmetry index of the kinematics for the ankle joint was positively correlated with that of jump height, but that for the knee joint was not. The current results indicate that, for collegiate basketball players, the asymmetry in the height of a RSJ can be attributed to that in the joint kinematics of the ankle during the takeoff phase, which may be associated with the ability to effectively transmit run-up velocity to jump height. Key pointsAsymmetry of height during running single leg jump between two legs is due to the behavior of the ankle joint (i.e. stiffer the ankle joint and explosive bounding).The dominant leg can transmit run-up velocity into the vertical velocity at takeoff phase to jump high compared with the non-dominant leg.Basketball players who have a greater asymmetry of the RSJ at the collegiate level could be assessed as non-regulars judging by the magnitude of asymmetry.

  9. Single-leg spica provides adequate stability after open reduction in developmental dysplasia of the hip.

    Science.gov (United States)

    Alassaf, Nabil

    2018-02-01

    The late detection of developmental dysplasia of the hip (DDH) will remain a major concern in some parts of the world until effective screening programs become available. With late diagnosis comes the need for open surgical reduction. Surgery is invariably followed by a period of immobilisation in a spica cast to prevent postoperative displacement. The goal of this study is to evaluate the effect of double-leg spica as compared to single-leg spica, on the risk of displacement after unilateral open reduction of the hip. This was a retrospective review of DDH patients from 2012 to 2016 and younger than 4 years of age, who had unilateral anterior open reduction. Patients who had one of the following were excluded: neuromuscular diagnosis, the addition of K-wire, and simultaneous bilateral open reductions. Demographic data were collected along with related clinical and radiographic variables. A total of 128 patients (162 hips) met the inclusion criteria; 93 were in the double-leg spica group, and 69 were in the single-leg spica group. The mean age was 25.4 ± 8.1 months and the mean follow-up was 18.6 ± 11.6 months. Baseline characteristics were balanced between the two groups. There were three events of redislocation in the double-leg spica group as compared to one redislocation in the single-leg spica group. The difference did not reach statistical significance (p = 0.637, risk ratio 1.317, CI 0.736-2.356). The difference in subsequent disruption of Shenton's line and hip migration of more than 29% was (p = 0.395, risk ratio 1.411, CI 0.892-2.234) and (p = 0.087, risk ratio 0.67, CI 0.417-1.078), respectively. Three patients had a greenstick distal femur fracture after double-leg spica and one after single-leg spica. These data suggest that including the contralateral hip in the cast after open reduction is not essential as it does not seem to improve stability.

  10. Physical Rehabilitation for Disabled People with Insulin-independent Diabetes after Single Leg Amputation

    Directory of Open Access Journals (Sweden)

    Nataliya A. Pilosyan

    2012-11-01

    Full Text Available The article presents the program of physical rehabilitation for the disabled people with insulin-independent diabetes, who came through single leg amputation. The program includes phantom-impulsive gymnastics, exercises for the remaining leg, back and shoulders, for the improvement of stump functional state, equilibrium exercises and exercises for arms supporting function development. Set of therapeutic exercises involves exercise machine training. The application of the developed physical rehabilitation program at the stage of preparation for fitting the prosthesis and learning to walk on prosthetic leg has proved its efficiency according to test results, biomedical methods of research and increases the motor activity of 100% percent of patients.

  11. Influence of shoes and foot orthoses on lower extremity muscle activation onset times in healthy subjects during the transition from double-leg stance to single-leg stance.

    Science.gov (United States)

    Dingenen, B; Peeraer, L; Deschamps, K; Fieuws, S; Janssens, L; Staes, F

    2015-01-01

    The aim of this study was to evaluate the influence of shoes and foot orthoses on lower extremity muscle activation patterns in healthy subjects during the transition from double-leg stance to single-leg stance. Eight male and seven female young asymptomatic adults who wear foot orthoses were recruited. Muscle activation onset times of 9 lower extremity muscles were recorded using surface electromyography during the transition from double-leg stance to single-leg stance, performed with eyes open and with eyes closed. This was tested in 4 experimental conditions: 1) barefoot (BF); 2) shoes only (SO); 3) shoes with standardized FO (SSFO); and 4) shoes with customized FO (SCFO). Based on a four-way (condition-region-leg-vision) linear model for repeated measures, we found a significant condition effect (P=0.025). Differences between conditions did not depend on the leg and/or the vision condition, but on the region (ankle-knee-hip). Based on a two-way (condition-muscle) linear model within each region, only significant differences between conditions for peroneus longus (P=0.003) were found. The onset times of peroneus longus were significantly earlier in SO (P=0.029) and SCFO (P=0.001) compared to BF. These results indicate that SO and SCFO can accelerate peroneus longus muscle activation onset times during the transition from double-leg stance to single-leg stance. Further research is required to determine how these adaptations may develop over time.

  12. Predicting muscle forces during the propulsion phase of single leg triple hop test.

    Science.gov (United States)

    Alvim, Felipe Costa; Lucareli, Paulo Roberto Garcia; Menegaldo, Luciano Luporini

    2018-01-01

    Functional biomechanical tests allow the assessment of musculoskeletal system impairments in a simple way. Muscle force synergies associated with movement can provide additional information for diagnosis. However, such forces cannot be directly measured noninvasively. This study aims to estimate muscle activations and forces exerted during the preparation phase of the single leg triple hop test. Two different approaches were tested: static optimization (SO) and computed muscle control (CMC). As an indirect validation, model-estimated muscle activations were compared with surface electromyography (EMG) of selected hip and thigh muscles. Ten physically healthy active women performed a series of jumps, and ground reaction forces, kinematics and EMG data were recorded. An existing OpenSim model with 92 musculotendon actuators was used to estimate muscle forces. Reflective markers data were processed using the OpenSim Inverse Kinematics tool. Residual Reduction Algorithm (RRA) was applied recursively before running the SO and CMC. For both, the same adjusted kinematics were used as inputs. Both approaches presented similar residuals amplitudes. SO showed a closer agreement between the estimated activations and the EMGs of some muscles. Due to inherent EMG methodological limitations, the superiority of SO in relation to CMC can be only hypothesized. It should be confirmed by conducting further studies comparing joint contact forces. The workflow presented in this study can be used to estimate muscle forces during the preparation phase of the single leg triple hop test and allows investigating muscle activation and coordination. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Single leg balancing in ballet: effects of shoe conditions and poses.

    Science.gov (United States)

    Lobo da Costa, Paula H; Azevedo Nora, Fernanda G S; Vieira, Marcus Fraga; Bosch, Kerstin; Rosenbaum, Dieter

    2013-03-01

    The purpose of this study was to describe the effects of lower limb positioning and shoe conditions on stability levels of selected single leg ballet poses performed in demi-pointe position. Fourteen female non-professional ballet dancers (mean age of 18.4±2.8 years and mean body mass index of 21.5±2.8kg/m(2)) who had practiced ballet for at least seven years, without any musculoskeletal impairment volunteered to participate in this study. A capacitive pressure platform allowed for the assessment of center of pressure variables related to the execution of three single leg ballet poses in demi pointé position: attitude devant, attitude derriére, and attitude a la second. Peak pressures, contact areas, COP oscillation areas, anterior-posterior and medio-lateral COP oscillations and velocities were compared between two shoe conditions (barefoot versus slippers) and among the different poses. Barefoot performances produced more stable poses with significantly higher plantar contact areas, smaller COP oscillation areas and smaller anterior-posterior COP oscillations. COP oscillation areas, anterior-posterior COP oscillations and medio-lateral COP velocities indicated that attitude a la second is the least challenging and attitude derriére the most challenging pose. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Reliability of Single-Leg Balance and Landing Tests in Rugby Union; Prospect of Using Postural Control to Monitor Fatigue

    Directory of Open Access Journals (Sweden)

    Jordan C. Troester, Jason G. Jasmin, Rob Duffield

    2018-06-01

    Full Text Available The present study examined the inter-trial (within test and inter-test (between test reliability of single-leg balance and single-leg landing measures performed on a force plate in professional rugby union players using commercially available software (SpartaMARS, Menlo Park, USA. Twenty-four players undertook test – re-test measures on two occasions (7 days apart on the first training day of two respective pre-season weeks following 48h rest and similar weekly training loads. Two 20s single-leg balance trials were performed on a force plate with eyes closed. Three single-leg landing trials were performed by jumping off two feet and landing on one foot in the middle of a force plate 1m from the starting position. Single-leg balance results demonstrated acceptable inter-trial reliability (ICC = 0.60-0.81, CV = 11-13% for sway velocity, anterior-posterior sway velocity, and mediolateral sway velocity variables. Acceptable inter-test reliability (ICC = 0.61-0.89, CV = 7-13% was evident for all variables except mediolateral sway velocity on the dominant leg (ICC = 0.41, CV = 15%. Single-leg landing results only demonstrated acceptable inter-trial reliability for force based measures of relative peak landing force and impulse (ICC = 0.54-0.72, CV = 9-15%. Inter-test results indicate improved reliability through the averaging of three trials with force based measures again demonstrating acceptable reliability (ICC = 0.58-0.71, CV = 7-14%. Of the variables investigated here, total sway velocity and relative landing impulse are the most reliable measures of single-leg balance and landing performance, respectively. These measures should be considered for monitoring potential changes in postural control in professional rugby union.

  15. Real-time feedback on knee abduction moment does not improve frontal-plane knee mechanics during jump landings.

    Science.gov (United States)

    Beaulieu, M L; Palmieri-Smith, R M

    2014-08-01

    Excessive knee abduction loading is a contributing factor to anterior cruciate ligament (ACL) injury risk. The purpose of this study was to determine whether a double-leg landing training program with real-time visual feedback improves frontal-plane mechanics during double- and single-leg landings. Knee abduction angles and moments and vertical ground reaction forces (GRF) of 21 recreationally active women were quantified for double- and single-leg landings before and after the training program. This program consisted of two sessions of double-leg jump landings with real-time visual feedback on knee abduction moments for the experimental group and without real-time feedback for the control group. No significant differences were found between training groups. In comparison with pre-training data, peak knee abduction moments decreased 12% post-training for both double- and single-leg landings; whereas peak vertical GRF decreased 8% post-training for double-leg landings only, irrespective of training group. Real-time feedback on knee abduction moments, therefore, did not significantly improve frontal-plane knee mechanics during landings. The effect of the training program on knee abduction moments, however, transferred from the double-leg landings (simple task) to single-leg landings (more complex task). Consequently, ACL injury prevention efforts may not need to focus on complex tasks during which injury occurs. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Ankle muscle activity modulation during single-leg stance differs between children, young adults and seniors.

    Science.gov (United States)

    Kurz, Eduard; Faude, Oliver; Roth, Ralf; Zahner, Lukas; Donath, Lars

    2018-02-01

    Incomplete maturation and aging-induced declines of the neuromuscular system affect postural control both in children and older adults and lead to high fall rates. Age-specific comparisons of the modulation of ankle muscle activation and behavioral center of pressure (COP) indices during upright stance have been rarely conducted. The objective of the present study was to quantify aging effects on a neuromuscular level. Thus, surface electromyography (SEMG) modulation and co-activity of ankle muscles during single-leg standing was compared in healthy children, young adults and seniors. Postural steadiness (velocity and mean sway frequency of COP), relative muscle activation (SEMG modulation) and co-activation of two ankle muscles (tibialis anterior, TA; soleus, SO) were examined during single-leg stance in 19 children [age, 9.7 (SD 0.5) years], 30 adults [23.3 (1.5) years] and 29 seniors [62.7 (6.1) years]. Velocity of COP in medio-lateral and anterior-posterior directions, mean sway frequency in anterior-posterior direction, relative muscle activation (TA and SO) and co-activation revealed large age effects (P  0.14). Post-hoc comparisons indicated higher COP velocities, anterior-posterior frequencies, relative SO activation and co-activation in children and seniors when compared with adults. Relative TA activation was higher in children and adults compared with seniors (P modulation. However, TA modulation is higher in children and adults, whereas seniors' TA modulation capacity is diminished. An aging-induced decline of TA motor units might account for deteriorations of TA modulation in seniors.

  17. Efeitos da crioterapia e facilitação neuromuscular proprioceptiva sobre a força muscular nas musculaturas flexora e extensora de joelho Effects of cryotherapy and proprioceptive neuromuscular facilitation on muscle strength at the flexor and extensor muscles of the knee

    Directory of Open Access Journals (Sweden)

    Daiana Moreira Mortari

    2009-12-01

    Full Text Available As musculaturas flexora e extensora do joelho são freqüentemente lesionadas devido a um desequilíbrio entre esses grupos. Recursos térmicos, como a crioterapia, e técnicas de alongamento, como a técnica mantém-relaxa da facilitação neuromuscular proprioceptiva (FNP, influenciam a flexibilidade e força muscular, proporcionando maior homogeneidade entre essas musculaturas e diminuindo a incidência de lesões. Este estudo objetivou verificar os efeitos da crioterapia e da FNP sobre a força das musculaturas flexora e extensora de joelho. A amostra foi composta por 18 mulheres com idade entre 18 e 24 anos, não-praticantes de atividade física regular, divididas em dois grupos: um submetido a crioterapia e o outro à técnica mantém-relaxa da FNP. Antes e após uma sessão de aplicação das técnicas foi feita avaliação isocinética. A aplicação da técnica mantém-relaxa provocou aumento da força em ambas as musculaturas em ambos os membros, atingindo nível de significância nos flexores do membro inferior direito (p=0,04. A crioterapia diminuiu a força dos extensores e exerceu efeito contrário sobre os flexores, tendo gerado aumento significativo nos flexores do membro inferior direito (p=0,035. Quando comparadas as técnicas, a técnica mantém-relaxa gerou maiores valores de pico de torque, principalmente nos extensores do membro inferior esquerdo (p=0,042. Conclui-se que a técnica mantém-relaxa da FNP gerou maiores valores no pico de torque em relação à crioterapia.Knee extensor and flexor muscles are often injured due to an imbalance between these groups, which may lead to a deficit in muscle performance. Thermal resources, such as cryotherapy, and stretching techniques, such as the "hold-relax" of proprioceptive neuromuscular facilitation (PNF, influence flexibility and muscle strength and may reduce the chances of muscle tendon injuries. The aim of the study was to verify the effects of cryotherapy and of the PNF

  18. Clinical Predictors of Knee Mechanics at Return to Sport after ACL Reconstruction.

    Science.gov (United States)

    Kline, Paul W; Johnson, Darren L; Ireland, Mary Lloyd; Noehren, Brian

    2016-05-01

    Despite significant rehabilitation, many athletes experience protracted weakness and faulty mechanics after anterior cruciate ligament reconstruction (ACLR). Clinical tests performed early in rehabilitation, which predict knee mechanics at return-to-sport, are virtually unknown and critically needed to guide clinical decision making. The purpose of this study is to determine if quadriceps strength, Y balance anterior (YB-A) reach distance, and single-leg step-down test performance (SLSD) conducted 3 months post-ACLR are predictive of knee flexion excursion (KFLEX) and knee extensor moment (KEM) during running 6 months post-ACLR. Thirty (16 females) subjects were collected 3 and 6 months post-ACLR. Age, 21.3 ± 7.6 yr; mass, 69.85 ± 11.4 kg; height, 1.73 ± 0.09 m. At 3 months post-ACLR, subjects performed isometric quadriceps strength testing, YB-A, and SLSD assessments. At 6 months post-ACLR, subjects underwent three-dimensional motion analysis while running on an instrumented treadmill. Pearson correlation coefficients and stepwise multiple regression were used to assess the relationships of 3-month and 6-month variables. Quadriceps strength (r = 0.493, P < 0.01), YB-A (r = 0.394, P = 0.03), and SLSD (r = 0.648, P < 0.01) were significantly correlated to KFLEX. Quadriceps strength (0.505, P < 0.01) and SLSD (.541, P < 0.01) were significantly correlated with KEM, whereas YB-A (.276, P = 0.06) was not. SLSD and quadriceps strength were predictive of KEM (adj R², 0.36; P = 0.001) whereas only SLSD was predictive of KFLEX (adj R², 0.40; P < 0.001). After ACLR, better performance in SLSD and quadriceps strength 3 months postsurgery is predictive of improved sagittal plane knee mechanics during running 6 months postsurgery.

  19. Low-level finite state control of knee joint in paraplegic standing

    NARCIS (Netherlands)

    Mulder, A.J.; Mulder, A.J.; Veltink, Petrus H.; Boom, H.B.K.; Zilvold, G.; Zilvold, G.

    1992-01-01

    Low-level finite state (locked-unlocked) control is compared with open-loop stimulation of the knee extensor muscles in functional electrical stimulation (FES) induced paraplegic standing. The parameters were: duration of standing, relative torque loss in knee extensor muscles, knee angle stability,

  20. RELIABILITY OF KINEMATICS AND KINETICS ASSOCIATED WITH HORIZONTAL SINGLE LEG DROP JUMP ASSESSMENT. A BRIEF REPORT

    Directory of Open Access Journals (Sweden)

    Markus Stålbom

    2007-06-01

    Full Text Available Determining the reliability of a unilateral horizontal drop jump for displacement provided the focus for this research. Eighteen male subjects were required to step off a 20cm box and land on a force plate with one leg and thereafter jump for maximal horizontal displacement on two different days. Dependent variables from the jump assessment included mean and peak vertical (V and horizontal (H ground reaction forces (GRF and impulses, horizontal displacement and contact time. The between-trial variability of all kinematic and kinetic measures was less than 7%. The most consistent measure over both trials was the horizontal displacement jumped (1.2 to 1.4% and the most variable were the contact time the first day (6.5% and peak HGRF the second day (4.3%. In all cases there was less variation associated with the second rather than the first day. In terms of test-retest variability the percent changes in the means and coefficient of variations (CVs were all under 10%. The smallest changes in the mean (0.43 %, least variation (< 2.26 % and second highest intraclass correlation co-efficient (ICC = 0.95 were found for horizontal displacement jumped. The highest ICC (0.96 was found for horizontal impulse. Given the reliability of the single leg drop jump, it may offer better prognostic and diagnostic information than that obtained with bilateral vertical jumps

  1. The Effect of Single-Leg Stance on Dancer and Control Group Static Balance.

    Science.gov (United States)

    Kilroy, Elisabeth A; Crabtree, Olivia M; Crosby, Brittany; Parker, Amanda; Barfield, William R

    The purpose of this study was to compare kinetic differences of static balance between female dancers (D) with at least seven years of dance experience and female non-dancers (ND) who were typical college students. Participants were tested in single-leg stance. Both the dominant leg (DL) and non-dominant leg (NDL) were tested with the participants shod (S) and barefoot (BF). Kinetic variables (vertical, medio-lateral [ML], antero-posterior [AP] maximum ground reaction forces (GRF), and center of pressure (COP) ML and AP) were measured by a Bertec force platform at 1000 Hz with participants S and BF. Each subject's stance was measured over 3 × 30-second intervals. No significant differences (p≥0.05) existed between groups for height, body mass, or age. Significant differences existed between groups for balance time, AP GRF in both BF and S conditions for both DL and NDL, and ML GRF in BF NDL and S DL and NDL conditions. D and ND in BF and S conditions with DL and NDL static stance demonstrate different AP and ML GRF when balancing over a 30-second time interval. Data may suggest that ND are more prone to lose their balance. Further investigation is warranted to understand whether individuals in the rehabilitative field and athletic populations can use dance therapy for injury prevention and rehabilitation.

  2. Effects of two football stud configurations on biomechanical characteristics of single-leg landing and cutting movements on infilled synthetic turf.

    Science.gov (United States)

    Brock, Elizabeth; Zhang, Songning; Milner, Clare; Liu, Xuan; Brosnan, James T; Sorochan, John C

    2014-11-01

    Multiple playing surfaces and footwear used in American football warrant a better understanding of relationship between different combinations of turf and footwear. The purpose of this study was to examine effects of shoe and stud types on ground reaction force (GRF) and ankle and knee kinematics of a 180° cut and a single-leg 90° land-cut on synthetic turf. Fourteen recreational football players performed five trials of the 180° cut and 90° land-cut in three shoe conditions: non-studded running shoe, and football shoe with natural and synthetic turf studs. Variables were analyzed with a 3 × 2 (shoe × movement) repeated measures analysis of variance (p < 0.05). Peak vertical GRF (p < 0.001) and loading rate (p < 0.001) were greater during 90° land-cut than 180° cut. For 180° cut, natural turf studs produced smaller peak medial GRFs compared to synthetic turf studs and non-studded shoe (p = 0.012). For land-cut, peak eversion velocity was reduced in running shoes compared to natural (p = 0.016) and synthetic (p = 0.002) turf studs. The 90° land-cut movement resulted in greater peak vertical GRF and loading rate compared to the 180° cut. Overall, increased GRFs in the 90° land-cut movement may increase the chance of injury.

  3. Chronic anterior knee pain in athletes: Common causes ...

    African Journals Online (AJOL)

    Anterior knee pain is a very common clinical presentation. In this article, the classification of anterior knee pain syndromes according to the anatomy of the knee extensor mechanism is described. The clinical diagnosis, special investigations, and principles of management of the more common causes of anterior knee pain ...

  4. Metric Tensor Vs. Metric Extensor

    OpenAIRE

    Fernández, V. V.; Moya, A. M.; Rodrigues Jr, Waldyr A.

    2002-01-01

    In this paper we give a comparison between the formulation of the concept of metric for a real vector space of finite dimension in terms of \\emph{tensors} and \\emph{extensors}. A nice property of metric extensors is that they have inverses which are also themselves metric extensors. This property is not shared by metric tensors because tensors do \\emph{not} have inverses. We relate the definition of determinant of a metric extensor with the classical determinant of the corresponding matrix as...

  5. The Comparing the Leg Muscles Electromyography during Single Leg Drop Landing in Pesplanus and Normal Men

    Directory of Open Access Journals (Sweden)

    mostafa bazvand

    2016-03-01

    Full Text Available Objective: pesplanus is one of the changes that brings about changes in muscle activation patterns. Being aware of muscles activity changes in various standing positions among pesplanus patients provides insights into preventing lower extremity injuries in this population. The aim of this study was to compare leg muscles electromyography during various standing positions in pesplanus and normal subjects. Methods: 60 healthy male university students, 30 subjects with pesplanus deformity (with average age 23/54±3/57 year, average height 175/34±7/62 cm, average weight 74/87±10/72 kg and 30 normal subjects (with average age 22/97±2/38 year, average height 176/6±5/59 cm, average weight 73/58±8/36 kg participated in this comparative study. Deformity of pesplanus was assessed with navicular drop test. Each subject performed single-leg landing dropping from 30cm height onto a force platform where muscles activity was recorded with EMG device. For data analysis, Matlab and Spss softwares were used and independent sample t-test was used to compare the dependent variables at a significance level of P &le 0/05. Results: Significant differences were observed between the two groups for the activities of the longus peroneus and anterior tibialis muscles ( p&le0/05 while no significant differences were observed in other muscles. Conclusion: The changes in the normal structure of the foot might affect muscle activities during standing, which can cause changes in the injury patterns. Therefore, it is proposed that focusing on corrective exercises and therapy plan can reduce these risks.

  6. Comparative Effects of Four Single Leg Squat Exercises in Subjects with Gluteus Medius Weakness.

    Science.gov (United States)

    Han, Hae-Rim; Yi, Chung-Hwi; You, Sung-Hyun; Cynn, Heon-Seock; Lim, One-Bin; Son, Jae-Ik

    2017-07-17

    Of the weight bearing exercises, single leg squat (SLS) represents one of the most commonly used hip strengthening exercises that require more gluteus medius (GMED) activity. To date, no studies have investigated how the four SLS exercises affects muscle imbalance of GMED, tensor fasciae latae (TFL), and adductor longus (AL), and kinematics of hip. To investigate the hip muscle activities, onset time, and kinematics during four different SLS exercises (unilateral squat, unilateral wall-squat, lateral step-down, and front step-down) in subjects with GMED weakness. Repeated-measures experimental design. Research laboratory. Twenty-two subjects (11 males and 11 females) participated in this study and were compared using one-way repeated analysis of variance. Surface electromyography was used to measure the muscle activities and onset time of the GMED, TFL, and AL, and 3-dimensional motion tracking system was used to measure the hip adduction and internal/external rotation angles during SLS exercises. One-way repeated analysis of variance was used at a significance level of p<0.05. The unilateral wall-squat produced higher GMED/TFL activity ratio and lower GMED/TFL onset time ratio than in the other three exercises (p<0.05). No difference in GMED/AL activity ratio and GMED/AL onset time ratio was observed. The hip adduction angle was greater in unilateral wall-squat than in the other three exercises (p<0.05). As for the hip internal/external rotation, lateral step-down exhibited higher hip internal rotation angle than front step-down (p<0.05). The unilateral wall-squat may be recommended as an effective exercise for the subjects with GMED weakness, but they should take care to avoid excessive hip adduction during the exercise.

  7. The effects of surface condition on abdominal muscle activity during single-legged hold exercise.

    Science.gov (United States)

    Ha, Sung-min; Oh, Jae-seop; Jeon, In-cheol; Kwon, Oh-yun

    2015-02-01

    To treat low-back pain, various spinal stability exercises are commonly used to improve trunk muscle function and strength. Because human movement for normal daily activity occurs in multi-dimensions, the importance of exercise in multi-dimensions or on unstable surfaces has been emphasized. Recently, a motorized rotating platform (MRP) for facilitating multi-dimensions dynamic movement was introduced for clinical use. However, the abdominal muscle activity with this device has not been reported. The purpose of this study was to compare the abdominal muscle activity (rectus abdominis, external and internal oblique muscles) during an active single-leg-hold (SLH) exercise on a floor (stable surface), foam roll, and motorized rotating platform (MRP). Thirteen healthy male subjects participated in this study. Using electromyography, the abdominal muscle activity was measured while the subjects performed SLH exercises on floor (stable surface), foam roll, and MRP. There were significant differences in the abdominal muscle activities among conditions (P.05) (Fig. 2). After the Bonferroni correction, however, no significant differences among conditions remained, except for differences in both side IO muscle activity between the floor and foam roll conditions (padjactivities of both side of RA and IO, and Rt. EO compared to floor condition. However, there were no significant differences in abdominal muscles activity in the multiple comparison between conditions (mean difference were smaller than the standard deviation in the abdominal muscle activities) (padj>0.017), except for differences in both side IO muscle activity between the floor (stable surface) and foam roll (padj<0.017) (effect size: 0.79/0.62 (non-supporting/supporting leg) for foam-roll versus floor). Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    DEFF Research Database (Denmark)

    Strøm, Mark; Thorborg, Kristian; Bandholm, Thomas

    2016-01-01

    BACKGROUND: A lateral ankle sprain is the most prevalent musculoskeletal injury in sports. Exercises that aim to improve balance are a standard part of the ankle rehabilitation process. In an optimal progression model for ankle rehabilitation and prevention of future ankle sprains, it is important...... to characterize different balance exercises based on level of difficulty and sensori-motor training stimulus. PURPOSE: The purpose of this study was to investigate frontal-plane ankle kinematics and associated peroneal muscle activity during single-legged balance on stable surface (floor) and three commonly used...... balance devices (Airex®, BOSU® Ball and wobble board). DESIGN: Descriptive exploratory laboratory study. METHODS: Nineteen healthy subjects performed single-legged balance with eyes open on an Airex® mat, BOSU® Ball, wobble board, and floor (reference condition). Ankle kinematics were measured using...

  9. Steadiness of Spinal Regions during Single-Leg Standing in Older Adults with and without Chronic Low Back Pain

    OpenAIRE

    Kuo, Yi-Liang; Huang, Kuo-Yuan; Chiang, Pei-Tzu; Lee, Pei-Yun; Tsai, Yi-Ju

    2015-01-01

    The aims of this study were to compare the steadiness index of spinal regions during single-leg standing in older adults with and without chronic low back pain (LBP) and to correlate measurements of steadiness index with the performance of clinical balance tests. Thirteen community-dwelling older adults (aged 55 years or above) with chronic LBP and 13 age- and gender-matched asymptomatic volunteers participated in this study. Data collection was conducted in a university research laboratory. ...

  10. Single-leg balance and core motor control in children: when does the risk for ACL injury occurs?

    OpenAIRE

    Hutchinson, Allison B; Yao, Paul; Hutchinson, Mark R

    2016-01-01

    Introduction While numerous publications have demonstrated the correlation of poor single-leg balance and core motor control with an increased risk of anterior cruciate ligament (ACL) injuries in skeletally mature female athletes, few have analysed the preadolescent population regarding when indeed comparative deficits in balance and core control actually occur. The purpose of this study was to assess whether the neuromotor factors that place mature females at increased risk of ACL injury act...

  11. Efeito de um programa de resistência muscular na capacidade funcional e na força muscular dos extensores do joelho em idosas pré-frágeis da comunidade: ensaio clínico aleatorizado do tipo crossover Impact of resistance exercise program on functional capacity and muscular strength of knee extensor in pre-frail community-dwelling older women: a randomized crossover trial

    Directory of Open Access Journals (Sweden)

    Lygia P. Lustosa

    2011-08-01

    vulnerability. OBJECTIVE: The aim of this study was to verify the effect of a muscle-strengthening program with load in pre-frail elder women with regards to the functional capacity, knee extensor muscle strength and their correlation. METHODS: Thrity-two pre-frail community-dwelling women participated in this study. Potential participants with cognitive impairment (MEEM, lower extremities orthopedic surgery, fractures, inability to walk unaided, neurological diseases, acute inflammatory disease, tumor growth, regular physical activity and current use of immunomodulators were excluded. All partcipants were evaluated by a blinded assessor using: Timed up and go (TUG, 10-Meter Walk Test (10MWT and knee extensor muscle strength (Byodex System 3 Pro® isokinetic dynamometer at angular speeds of 60 and 180(0/s. The intervention consisted of strengthening exercises of the lower extremities at 70% of 1RM, three times/ week for ten weeks. The statistical analysis was performed using the ANOVA and Spearman tests RESULTS: After the intervention, it was observed statistical significance on the work at 180(0/s (F=12.71, p=0.02, on the power at 180(0/s (F=15.40, p=0.02 and on the functional capacity (TUG, F=9.54, p=0.01; TC10, F=3.80, p=0.01. There was a good negative and statistically significant correlation between the TUG and work at 60(0/s, such as the TUG and work at 180(0/s (r=-0.65, p=0.01; r=-0.72, p=0.01. CONCLUSION: The intervention improved the muscular power and the functional capacity. The increase of the power correlated with function, which is an important variable of the quality of life in the pre-frail elders. Article registered in the ISRCT register under number ISRCTN62824599.

  12. Technology in Rehabilitation: Evaluating the Single Leg Squat Exercise with Wearable Inertial Measurement Units.

    Science.gov (United States)

    Whelan, Darragh F; O'Reilly, Martin A; Ward, Tomás E; Delahunt, Eamonn; Caulfield, Brian

    2017-03-23

    The single leg squat (SLS) is a common lower limb rehabilitation exercise. It is also frequently used as an evaluative exercise to screen for an increased risk of lower limb injury. To date athlete / patient SLS technique has been assessed using expensive laboratory equipment or subjective clinical judgement; both of which are not without shortcomings. Inertial measurement units (IMUs) may offer a low cost solution for the objective evaluation of athlete / patient SLS technique. The aims of this study were to determine if in combination or in isolation IMUs positioned on the lumbar spine, thigh and shank are capable of: (a) distinguishing between acceptable and aberrant SLS technique; (b) identifying specific deviations from acceptable SLS technique. Eighty-three healthy volunteers participated (60 males, 23 females, age: 24.68 + / - 4.91 years, height: 1.75 + / - 0.09 m, body mass: 76.01 + / - 13.29 kg). All participants performed 10 SLSs on their left leg. IMUs were positioned on participants' lumbar spine, left shank and left thigh. These were utilized to record tri-axial accelerometer, gyroscope and magnetometer data during all repetitions of the SLS. SLS technique was labelled by a Chartered Physiotherapist using an evaluation framework. Features were extracted from the labelled sensor data. These features were used to train and evaluate a variety of random-forests classifiers that assessed SLS technique. A three IMU system was moderately successful in detecting the overall quality of SLS performance (77 % accuracy, 77 % sensitivity and 78 % specificity). A single IMU worn on the shank can complete the same analysis with 76 % accuracy, 75 % sensitivity and 76 % specificity. Single sensors also produce competitive classification scores relative to multi-sensor systems in identifying specific deviations from acceptable SLS technique. A single IMU positioned on the shank can differentiate between acceptable and aberrant

  13. Foot muscle morphology is related to center of pressure sway and control mechanisms during single-leg standing.

    Science.gov (United States)

    Zhang, Xianyi; Schütte, Kurt Heinrich; Vanwanseele, Benedicte

    2017-09-01

    Maintaining balance is vitally important in everyday life. Investigating the effects of individual foot muscle morphology on balance may provide insights into neuromuscular balance control mechanisms. This study aimed to examine the correlation between the morphology of foot muscles and balance performance during single-leg standing. Twenty-eight recreational runners were recruited in this study. An ultrasound device was used to measure the thickness and cross-sectional area of three intrinsic foot muscles (abductor hallucis, flexor digitorum brevis and quadratus plantae) and peroneus muscles. Participants were required to perform 30s of single-leg standing for three trials on a force plate, which was used to record the center of pressure (COP). The standard deviation of the amplitude and ellipse area of the COP were calculated. In addition, stabilogram diffusion analysis (SDA) was performed on COP data. Pearson correlation coefficients were computed to examine the correlation between foot muscle morphology and traditional COP parameters as well as with SDA parameters. Our results showed that larger abductor hallucis correlated to smaller COP sway, while larger peroneus muscles correlated to larger COP sway during single-leg standing. Larger abductor hallucis also benefited open-loop dynamic stability, as well as supported a more efficient transfer from open-loop to closed loop control mechanisms. These results suggest that the morphology of foot muscles plays an important role in balance performance, and that strengthening the intrinsic foot muscles may be an effective way to improve balance. Copyright © 2017. Published by Elsevier B.V.

  14. Quantifying kinematic differences between land and water during squats, split squats, and single-leg squats in a healthy population.

    Directory of Open Access Journals (Sweden)

    Anna C Severin

    Full Text Available Aquatic exercises can be used in clinical and sporting disciplines for both rehabilitation and sports training. However, there is limited knowledge on the influence of water immersion on the kinematics of exercises commonly used in rehabilitation and fitness programs. The aim of this study was to use inertial sensors to quantify differences in kinematics and movement variability of bodyweight squats, split squats, and single-leg squats performed on dry land and whilst immersed to the level of the greater trochanter. During two separate testing sessions, 25 active healthy university students (22.3±2.9 yr. performed ten repetitions of each exercise, whilst tri-axial inertial sensors (100 Hz recorded their trunk and lower body kinematics. Repeated-measures statistics tested for differences in segment orientation and speed, movement variability, and waveform patterns between environments, while coefficient of variance was used to assess differences in movement variability. Between-environment differences in segment orientation and speed were portrayed by plotting the mean difference ±95% confidence intervals (CI throughout the tasks. The results showed that the depth of the squat and split squat were unaffected by the changed environment while water immersion allowed for a deeper single leg squat. The different environments had significant effects on the sagittal plane orientations and speeds for all segments. Water immersion increased the degree of movement variability of the segments in all exercises, except for the shank in the frontal plane, which showed more variability on land. Without compromising movement depth, the aquatic environment induces more upright trunk and shank postures during squats and split squats. The aquatic environment allows for increased squat depth during the single-leg squat, and increased shank motions in the frontal plane. Our observations therefore support the use of water-based squat tasks for rehabilitation as

  15. Quantifying kinematic differences between land and water during squats, split squats, and single-leg squats in a healthy population.

    Science.gov (United States)

    Severin, Anna C; Burkett, Brendan J; McKean, Mark R; Wiegand, Aaron N; Sayers, Mark G L

    2017-01-01

    Aquatic exercises can be used in clinical and sporting disciplines for both rehabilitation and sports training. However, there is limited knowledge on the influence of water immersion on the kinematics of exercises commonly used in rehabilitation and fitness programs. The aim of this study was to use inertial sensors to quantify differences in kinematics and movement variability of bodyweight squats, split squats, and single-leg squats performed on dry land and whilst immersed to the level of the greater trochanter. During two separate testing sessions, 25 active healthy university students (22.3±2.9 yr.) performed ten repetitions of each exercise, whilst tri-axial inertial sensors (100 Hz) recorded their trunk and lower body kinematics. Repeated-measures statistics tested for differences in segment orientation and speed, movement variability, and waveform patterns between environments, while coefficient of variance was used to assess differences in movement variability. Between-environment differences in segment orientation and speed were portrayed by plotting the mean difference ±95% confidence intervals (CI) throughout the tasks. The results showed that the depth of the squat and split squat were unaffected by the changed environment while water immersion allowed for a deeper single leg squat. The different environments had significant effects on the sagittal plane orientations and speeds for all segments. Water immersion increased the degree of movement variability of the segments in all exercises, except for the shank in the frontal plane, which showed more variability on land. Without compromising movement depth, the aquatic environment induces more upright trunk and shank postures during squats and split squats. The aquatic environment allows for increased squat depth during the single-leg squat, and increased shank motions in the frontal plane. Our observations therefore support the use of water-based squat tasks for rehabilitation as they appear to

  16. Single leg jumping neuromuscular control is improved following whole body, long-axis rotational training.

    Science.gov (United States)

    Nyland, John; Burden, Robert; Krupp, Ryan; Caborn, David N M

    2011-04-01

    Improved lower extremity neuromuscular control during sports may decrease injury risk. This prospective study evaluated progressive resistance, whole body, long-axis rotational training on the Ground Force 360 device. Our hypothesis was that device training would improve lower extremity neuromuscular control based on previous reports of kinematic, ground reaction force (GRF) or electromyographic (EMG) evidence of safer or more efficient dynamic knee stability during jumping. Thirty-six healthy subjects were randomly assigned to either training (Group 1) or control (Group 2) groups. Using a pre-test, post-test study design data were collected from three SLVJ trials. Unpaired t-tests with adjustments for multiple comparisons were used to evaluate group mean change differences (P≤0.05/25≤0.002). During propulsion Group 1 standardized EMG amplitude mean change differences for gluteus maximus (-21.8% vs. +17.4%), gluteus medius (-28.6% vs. +15.0%), rectus femoris (-27.1% vs. +11.2%), vastus medialis (-20.2% vs. +9.1%), and medial hamstrings (-38.3% vs. +30.3%) differed from Group 2. During landing Group 1 standardized EMG amplitude mean change differences for gluteus maximus (-32.9% vs. +11.1%) and rectus femoris (-33.3% vs. +29.0%) also differed from Group 2. Group 1 peak propulsion vertical GRF (+0.24N/kg vs. -0.46N/kg) and landing GRF stabilization timing (-0.68 vs. +0.05s) mean change differences differed from Group 2. Group 1 mean hip (-16.3 vs. +7.8°/s) and knee (-21.4 vs. +18.5°/s) flexion velocity mean change differences also differed from Group 2. Improved lower extremity neuromuscular efficiency, increased peak propulsive vertical GRF, decreased mean hip and knee flexion velocities during landing, and earlier landing stabilization timing in the training group suggests improved lower extremity neuromuscular control. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Quadriceps strength and anterior knee pain following tibia ...

    African Journals Online (AJOL)

    The tension generated on extension of the knee against a resistance using tensiometer was measured in Newton. ... There was no statistically significant relationship between the force of tension (N) generated in the extensor in patients with anterior knee pain compared with those without knee pain (158.43 ± 49.35, 189.54 ...

  18. Individuals with chronic ankle instability exhibit decreased postural sway while kicking in a single-leg stance.

    Science.gov (United States)

    dos Santos, Marcio José; Gorges, Ana Luiza; Rios, Jaqueline Lourdes

    2014-01-01

    Individuals with chronic ankle instability (CAI) usually experience deficits in balance control, which increase displacement in the body's center of pressure (COP) when they balance on a single leg. Little is known, however, about whether or not these individuals use the strategies of postural adjustment properly, especially during functional tasks that may predispose them to ankle sprain. The aim of this study was to investigate anticipatory (APA) and compensatory (CPA) postural adjustments in individuals with and without CAI as they kick a ball while standing in a single-leg stance with their ankle in neutral and supinated positions. COP displacements were calculated and their magnitudes (range) analyzed during APA and CPA intervals and over the duration of the whole task, represented by the COP area of sway and mean velocity. The CAI group exhibited a significant decrease in CPA and area of sway over the whole task, relative to controls. These results suggest that the decreased balance sway could be caused by the need for further stabilization of the ankle in more unstable postures to prevent recurrent sprain. Our findings could help clinicians to better understand the strategies of postural adjustments in individuals with CAI, and may assist and motivate new investigations into balance control interventions in such individuals, as well as proactively address recurrent ankle sprain conditions. Published by Elsevier B.V.

  19. First approach to automatic measurement of frontal plane projection angle during single leg landing based on depth video

    NARCIS (Netherlands)

    Bailon, Carlos; Damas, Miguel; Pomares, Hector; Banos Legran, Oresti

    2016-01-01

    Knee alignment measurements are one of the most extended indicators of knee complex injuries such as anterior cruciate ligament injury and patellofemoral pain syndrome. The Frontal Plane Projection Angle (FPPA) is widely used as a 2D estimation of knee alignment. However, traditional procedures to

  20. Effects of tension of Kinesio taping application on maximum quadriceps torque and knee repositioning sense in recreationally males

    Directory of Open Access Journals (Sweden)

    Mostafa Mohammadi

    2018-04-01

    Conclusion: According to the results, Kinesio taping could influence on repositioning sense of the knee joint at 60-degree knee flexion. Maximum concentric and eccentric extensor torques was also increased.

  1. Epidemiology of jumper's knee.

    Science.gov (United States)

    Ferretti, A

    1986-01-01

    Jumper's knee is a typical functional overload injury because it affects those athletes who submit their knee extensor mechanisms to intense and repeated stress, e.g. volleyball and basketball players, high and long jumpers. According to the classification of Perugia and colleagues, it is an insertional tendinopathy affecting, in order of frequency, the insertion of the patellar tendon into the patella (65% of cases), attachment of the quadriceps tendon to the patella (25%) and the attachment of the patellar tendon to the tibial tuberosity (10%). The frequent occurrence of this injury in athletes led to the study of factors that may contribute to its onset and aggravation. These factors are divided into extrinsic (i.e. kind of sport practised and training methods used) and intrinsic (i.e. connected with the somatic and morphological characteristics of the athletes). On the basis of our experience and after a review of the literature it appears, contrary to what has been repeatedly claimed in the past, the extrinsic factors are more important than the intrinsic in the aetiology of jumper's knee. The effect of traumatic incidents and use of elastic kneecap guards should also be considered negligible. The intrinsic causes of jumper's knee, can be sought in the mechanical properties of tendons (resistance, elasticity and extensibility) rather than in morphological or biomechanical abnormalities of the knee extensor mechanism.

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

    DEFF Research Database (Denmark)

    Strøm, Mark; Thorborg, Kristian; Bandholm, Thomas

    2016-01-01

    to characterize different balance exercises based on level of difficulty and sensori-motor training stimulus. PURPOSE: The purpose of this study was to investigate frontal-plane ankle kinematics and associated peroneal muscle activity during single-legged balance on stable surface (floor) and three commonly used...... compared to Airex® and floor. This study can serve as guidance for clinicians who wish to implement a gradual progression of ankle rehabilitation and prevention exercises by taking the related ankle kinematics and muscle activity into account. LEVEL OF EVIDENCE: Level 3.......BACKGROUND: A lateral ankle sprain is the most prevalent musculoskeletal injury in sports. Exercises that aim to improve balance are a standard part of the ankle rehabilitation process. In an optimal progression model for ankle rehabilitation and prevention of future ankle sprains, it is important...

  3. Steadiness of Spinal Regions during Single-Leg Standing in Older Adults with and without Chronic Low Back Pain.

    Directory of Open Access Journals (Sweden)

    Yi-Liang Kuo

    Full Text Available The aims of this study were to compare the steadiness index of spinal regions during single-leg standing in older adults with and without chronic low back pain (LBP and to correlate measurements of steadiness index with the performance of clinical balance tests. Thirteen community-dwelling older adults (aged 55 years or above with chronic LBP and 13 age- and gender-matched asymptomatic volunteers participated in this study. Data collection was conducted in a university research laboratory. Measurements were steadiness index of spinal regions (trunk, thoracic spine, lumbar spine, and pelvis during single-leg standing including relative holding time (RHT and relative standstill time (RST, and clinical balance tests (timed up and go test and 5-repetition sit to stand test. The LBP group had a statistically significantly smaller RHT than the control group, regardless of one leg stance on the painful or non-painful sides. The RSTs on the painful side leg in the LBP group were not statistically significantly different from the average RSTs of both legs in the control group; however, the RSTs on the non-painful side leg in the LBP group were statistically significantly smaller than those in the control group for the trunk, thoracic spine, and lumbar spine. No statistically significant intra-group differences were found in the RHTs and RSTs between the painful and non-painful side legs in the LBP group. Measurements of clinical balance tests also showed insignificant weak to moderate correlations with steadiness index. In conclusion, older adults with chronic LBP demonstrated decreased spinal steadiness not only in the symptomatic lumbar spine but also in the other spinal regions within the kinetic chain of the spine. When treating older adults with chronic LBP, clinicians may also need to examine their balance performance and spinal steadiness during balance challenging tests.

  4. Outcomes associated with early post-traumatic osteoarthritis and other negative health consequences 3-10 years following knee joint injury in youth sport.

    Science.gov (United States)

    Whittaker, J L; Woodhouse, L J; Nettel-Aguirre, A; Emery, C A

    2015-07-01

    Post-traumatic osteoarthritis (PTOA) commonly affects the knee joint. Although the risk of PTOA substantially increases post-joint injury, there is little research examining PTOA outcomes early in the period between joint injury and disease onset. Improved understanding of this interval would inform secondary prevention strategies aimed at preventing and/or delaying PTOA progression. This study examines the association between sport-related knee injury and outcomes related to development of PTOA, 3-10 years post-injury. This preliminary analysis of the first year of a historical cohort study includes 100 (15-26 years) individuals. Fifty with a sport-related intra-articular knee injury sustained 3-10 years previously and 50 uninjured age, sex and sport matched controls. The primary outcome was the 'Symptoms' sub-scale of the Knee Osteoarthritis and Injury Outcome Score (KOOS). Secondary outcomes included; the remaining KOOS subscales, body mass index (BMI), hip abductor/adductor and knee extensor/flexor strength, estimated aerobic capacity (VO2max) and performance scores on three dynamic balance tests. Descriptive statistics (mean within-pair difference; 95% Confidence interval (CI) and conditional odds ratio (OR, 95% CI; BMI) were used to compare study groups. Injured participants demonstrated poorer KOOS outcomes [symptoms -9.4 (-13.6, -5.2), pain -4.0 (-6.8, -1.2), quality-of-life -8.0 (-11.0, -5.1), daily living -3.0 (-5.0, -1.1) and sport/recreation -6.9 (-9.9, -3.8)], were 3.75 times (95% CI 1.24, 11.3) more likely to be overweight/obese and had lower triple single leg hop scores compared to controls. No significant group differences existed for remaining balance scores, estimated VO2max, hip or knee strength ratios or side-to-side difference in hip abductor/adductor or quadricep/hamstring strength. This study provides preliminary evidence that youth/young adults following sport-related knee injury report more symptoms and poorer function, and are at

  5. Medio-lateral knee fluency in anterior cruciate ligament-injured athletes during dynamic movement trials.

    Science.gov (United States)

    Panos, Joseph A; Hoffman, Joshua T; Wordeman, Samuel C; Hewett, Timothy E

    2016-03-01

    Correction of neuromuscular impairments after anterior cruciate ligament injury is vital to successful return to sport. Frontal plane knee control during landing is a common measure of lower-extremity neuromuscular control and asymmetries in neuromuscular control of the knee can predispose injured athletes to additional injury and associated morbidities. Therefore, this study investigated the effects of anterior cruciate ligament injury on knee biomechanics during landing. Two-dimensional frontal plane video of single leg drop, cross over drop, and drop vertical jump dynamic movement trials was analyzed for twenty injured and reconstructed athletes. The position of the knee joint center was tracked in ImageJ software for 500 milliseconds after landing to calculate medio-lateral knee motion velocities and determine normal fluency, the number of times per second knee velocity changed direction. The inverse of this calculation, analytical fluency, was used to associate larger numerical values with fluent movement. Analytical fluency was decreased in involved limbs for single leg drop trials (P=0.0018). Importantly, analytical fluency for single leg drop differed compared to cross over drop trials for involved (Pinjury. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Time series of ground reaction forces following a single leg drop jump landing in elite youth soccer players consist of four distinct phases

    NARCIS (Netherlands)

    Fransz, Duncan P.; Huurnink, Arnold; de Boode, Vosse A.; Kingma, Idsart; van Dieën, Jaap H.

    2016-01-01

    The single leg drop jump landing test may assess dynamic and static balance abilities in different phases of the landing. However objective definitions of different phases following landing and associated reliability are lacking. Therefore, we determined the existence of possible distinct phases of

  7. Knee pain

    Science.gov (United States)

    Pain - knee ... Knee pain can have different causes. Being overweight puts you at greater risk for knee problems. Overusing your knee can trigger knee problems that cause pain. If you have a history of arthritis, it ...

  8. Lower Limb Symmetry: Comparison of Muscular Power Between Dominant and Nondominant Legs in Healthy Young Adults Associated With Single-Leg-Dominant Sports.

    Science.gov (United States)

    Vaisman, Alex; Guiloff, Rodrigo; Rojas, Juan; Delgado, Iris; Figueroa, David; Calvo, Rafael

    2017-12-01

    Achieving a symmetrical power performance (difference symmetry does not act as a viable comparison. To (1) compare maximal muscular power between the dominant and nondominant legs in healthy young adults, (2) evaluate the effect of a single-leg-dominant sport activity performed at the professional level, and (3) propose a parameter of normality for maximal power difference in the lower limbs of this young adult population. Controlled laboratory study. A total of 78 healthy, male, young adults were divided into 2 groups according to sport activity level. Group 1 consisted of 51 nonathletes (mean ± SD age, 20.8 ± 1.5 years; weight, 71.9 ± 10.5 kg) who participated in less than 8 hours a week of recreational physical activity with nonspecific training; group 2 consisted of 27 single-leg-dominant professional soccer players (age, 18.4 ± 0.6 years; weight, 70.1 ± 7.5 kg) who specifically trained and competed at their particular activity 8 hours or more a week. For assessment of maximal leg power, both groups completed the single-leg squat jump test. Dominance was determined when participants completed 2 of 3 specific tests with the same extremity. Statistical analysis included the Student t test. No statistical difference was found for maximal power between dominant and nondominant legs for nonathletes ( t = -1.01, P = .316) or single-leg-dominant professional soccer players ( t = -1.10, P = .281). A majority (95%) of participants studied showed a power difference of less than 15% between their lower extremities. Among young healthy adults, symmetrical power performance is expected between lower extremities independent of the existence of dominance and difference in sport activity level. A less than 15% difference in power seems to be a proper parameter to define symmetrical power performance assessed by vertical single-leg jump tests.

  9. Comparison of Abdominal Muscle Activity During a Single-Legged Hold in the Hook-Lying Position on the Floor and on a Round Foam Roll

    Science.gov (United States)

    Kim, Su-Jung; Kwon, Oh-Yun; Yi, Chung-Hwi; Jeon, Hye-Seon; Oh, Jae-Seop; Cynn, Heon-Seock; Weon, Jong-Hyuck

    2011-01-01

    Context: To improve trunk stability or trunk muscle strength, many athletic trainers and physiotherapists use various types of unstable equipment for training. The round foam roll is one of those unstable pieces of equipment and may be useful for improving trunk stability. Objective: To assess the effect of the supporting surface (floor versus round foam roll) on the activity of abdominal muscles during a single-legged hold exercise performed in the hook-lying position on the floor and on a round foam roll. Design: Crossover study. Setting: University research laboratory. Patients or Other Participants: Nineteen healthy volunteers (11 men, 8 women) from a university population. Interventions : The participants were instructed to perform a single-legged hold exercise while in the hook-lying position on the floor (stable surface) and on a round foam roll (unstable surface). Main Outcome Measure(s): Surface electromyography (EMG) signals were recorded from the bilateral rectus abdominis, internal oblique, and external oblique muscles. Dependent variables were examined with a paired t test. Results: The EMG activities in all abdominal muscles were greater during the single-legged hold exercise performed on the round foam roll than on the stable surface. Conclusions: The single-legged hold exercise in the hook-lying position on an unstable supporting surface induced greater abdominal muscle EMG amplitude than the same exercise performed on a stable supporting surface. These results suggest that performing the single-legged hold exercise while in the hook-lying position on a round foam roll is useful for activating the abdominal muscles. PMID:21944072

  10. Physiological responses to incremental, interval, and continuous counterweighted single-leg and double-leg cycling at the same relative intensities.

    Science.gov (United States)

    MacInnis, Martin J; Morris, Nathaniel; Sonne, Michael W; Zuniga, Amanda Farias; Keir, Peter J; Potvin, Jim R; Gibala, Martin J

    2017-07-01

    We compared physiological responses to incremental, interval, and continuous counterweighted single-leg and double-leg cycling at the same relative intensities. The primary hypothesis was that the counterweight method would elicit greater normalized power (i.e., power/active leg), greater electromyography (EMG) responses, and lower cardiorespiratory demand. Graded-exercise tests performed by 12 men (age: 21 ± 2 years; BMI: 24 ± 3 kg/m 2 ) initially established that peak oxygen uptake ([Formula: see text]; 76 ± 8.4%), expired ventilation ([Formula: see text]; 71 ± 6.8%), carbon dioxide production ([Formula: see text]; 71 ± 6.8%), heart rate (HRpeak; 91 ± 5.3%), and power output (PPO; 56 ± 3.6%) were lower during single-leg compared to double-leg cycling (main effect of mode; p cycling were performed at greater absolute power outputs but lower normalized power outputs compared to single-leg cycling (p  0.05), but semitendinosus was activated to a greater extent for single-leg cycling (p = 0.005). Single-leg interval and continuous cycling elicited lower mean [Formula: see text], [Formula: see text], [Formula: see text], HR and ratings of perceived exertion compared to double-leg cycling (p cycling elicits lower cardiorespiratory and perceptual responses than double-leg cycling at greater normalized power outputs.

  11. THE EFFECTS OF SINGLE LEG HOP PROGRESSION AND DOUBLE LEGS HOP PROGRESSION EXERCISE TO INCREASE SPEED AND EXPLOSIVE POWER OF LEG MUSCLE

    Directory of Open Access Journals (Sweden)

    Nining W. Kusnanik

    2015-05-01

    Full Text Available The main purpose of this study was to determine the effect of single leg hop progression and double legs hop progression exercise to increase speed and explosive power of leg muscles. Plyometric is one of the training methods that can increase explosive power. There are many models of plyometric training including single leg hop progression and double leg hop progression. This research was experimental using match subject design techniques. The subjects of this study were 39 students who joined basketball school club. There were 3 groups in this study: Group 1 were 13 students who given sin¬gle leg hop progression exercise, Group 2 were 13 students who given double legs hop progression exercise, Group 3 were 13 students who given conventional exercise. The data was collected during pre test and post test by testing 30m speed running and vertical jump. The data was analyzed using Analysis of Varians (Anova. It was found that there were significantly increased on speed and explosive power of leg muscles of Group 1 and Group 2. It can be stated that single leg hop progression exercise was more effective than double leg hop progression exercise. The recent findings supported the hypothesis that single leg hop progression and double legs hop progression exercise can increase speed and explosive power of leg muscles. These finding were supported by some previous studies (Singh, et al, 2011; Shallaby, H.K., 2010. The single leg hop progression is more effective than double legs hop progression. This finding was consistent with some previous evidences (McCurdy, et al, 2005; Makaruk et al, 2011.

  12. Single-leg drop landing movement strategies 6 months following first-time acute lateral ankle sprain injury.

    Science.gov (United States)

    Doherty, C; Bleakley, C; Hertel, J; Caulfield, B; Ryan, J; Delahunt, E

    2015-12-01

    No research exists predicating a link between acute ankle sprain injury-affiliated movement patterns and those of chronic ankle instability (CAI) populations. The aim of the current study was to perform a biomechanical analysis of participants, 6 months after they sustained a first-time acute lateral ankle sprain (LAS) injury to establish this link. Fifty-seven participants with a 6-month history of first-time LAS and 20 noninjured participants completed a single-leg drop landing task on both limbs. Three-dimensional kinematic (angular displacement) and sagittal plane kinetic (moment of force) data were acquired for the joints of the lower extremity, from 200 ms pre-initial contact (IC) to 200 ms post-IC. Individual joint stiffnesses and the peak magnitude of the vertical component of the ground reaction force (GRF) were also computed. LAS participants displayed increases in hip flexion and ankle inversion on their injured limb (P < 0.05); this coincided with a reduction in the net flexion-extension moment at the hip joint, with an increase in its stiffness (P < 0.05). There was no difference in the magnitude of the peak vertical GRF for either limb compared with controls. These results demonstrate that altered movement strategies persist in participants, 6 months following acute LAS, which may precipitate the onset of CAI. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. The effects of attentional focus on jump performance and knee joint kinematics in patients after ACL reconstruction

    NARCIS (Netherlands)

    Gokeler, Alli; Benjaminse, Anne; Welling, Wouter; Alferink, Malou; Eppinga, Peter; Otten, Bert

    Objectives: The purpose of this study was to determine the effect of an internal and external attentional focus on single leg hop jump distance and knee kinematics in patients after ACL reconstruction (ACLR). Design: Experimental. Setting: Outpatient physical therapy facility. Participants: Sixteen

  14. Knee joint replacement

    Science.gov (United States)

    Total knee replacement; Knee arthroplasty; Knee replacement - total; Tricompartmental knee replacement; Subvastus knee replacement; Knee replacement - minimally invasive; Knee arthroplasty - minimally ...

  15. Vascularization and anatomical model of the mesotendons of the extensor digitorum and extensor indicis muscles.

    OpenAIRE

    Zbrodowski, A; Gajisin, S; Grodecki, J

    1980-01-01

    In ten human hands the mesotendons of m. extensor digitorum longus and m. extensor indicis have been examined and described in detail. The various sources of their blood supplies have also been demonstrated and described.

  16. Reproducibility of Dynamic Body Balance Measurement by Center of Foot Pressure Analysis Immediately after Single-Leg Hop Landing.

    Science.gov (United States)

    Kawakami, Yukiko; Yonetani, Yasukazu; Takao, Rikio; Ogasawara, Issei; Mae, Tatsuo; Nakata, Ken; Horibe, Shuji

    2016-01-01

    Dynamic balance was evaluated using the trajectory length of the center of foot pressure (COP) in the early phase from immediately after landing to the time of pastoral maintenance. Ten young volunteers with an average age of 23.8 years were asked to stand on one foot on a horizontal floor, hop forward half a step and land on one foot 10 times on each of 3 non-consecutive days. The peak of the vertical component of the floor reaction force (Fz), and the initiation time of the maximum value (tz) and COP trajectory length were measured by a force plate (AMTI, Ltd.). None of the subjects complained of any feeling of fear or loss of balance during the 3 days.The interclass correlation coefficient values of Fz and tz over the three days were 0.75 or higher. Single-leg hop for half a step as a motor task enabled safe measurement of COP trajectory length with high reproducibility. Fz reached its peak within 200 ms after landing and the COP trajectory length within 200 ms after landing accounted for approximately 50% of the total COP trajectory length at one second. Although the length differed in each subject, the interclass correlation coefficients for COP up to 100 ms and 200 ms were 0.68 and 0.80, respectively.The COP trajectory length within 200 ms after landing was considered to be useful as an objective criteria for the evaluation of dynamic balance in the early phase after landing.

  17. Knee Bursitis

    Science.gov (United States)

    ... frequent falls on the knee — such as wrestling, football and volleyball — can increase your risk of knee ... or repetitious bending of your knees increases the force on your knee joints. Achieve and maintain a ...

  18. Single-leg squats identify independent stair negotiation ability in older adults referred for a physiotherapy mobility assessment at a rural hospital.

    Science.gov (United States)

    Hockings, Rowena L; Schmidt, David D; Cheung, Christopher W

    2013-07-01

    To determine whether single-leg squats identify ability to negotiate stairs in older adults at a rural hospital. Cross-sectional analytical study. Acute wards and emergency department of a rural hospital in Australia. A systematic sample of 143 older adults (72 men, 71 women, 80.0 ± 6.8 years) from the emergency department or acute wards of Shoalhaven Hospital referred for a physiotherapy mobility assessment. Ability to complete up to three single-leg squats and negotiate up to three steps were measured. Covariates and demographic variables were collected. The squat test had 86% sensitivity, 100% specificity, 100% positive predictive value, and 49% negative predictive value in correctly identifying stair negotiation ability. Participants who could complete single-leg squats were 57 times more likely to be able to independently negotiate stairs than participants who could not complete squats. Multivariate regression analysis indicated that walker use, pain severity and whether participants lived alone were significant and independent predictors of ability to negotiate stairs independently. Single-leg squats may be an accurate identifier of stair negotiation ability in older adults admitted to the hospital for an acute illness or injury. A traditional stairs assessment would be required if older adults were unable to complete the squat test or had moderate to severe pain, used a walker to ambulate, or did not live alone. The squat test is a potentially more-efficient assessment tool than traditional stair assessments in determining an individual's ability to negotiate stairs and suitability for discharge where poor mobility is a problem. © 2013, Copyright the Authors Journal compilation © 2013, The American Geriatrics Society.

  19. Postural stability during the transition from double-leg stance to single-leg stance in anterior cruciate ligament injured subjects.

    Science.gov (United States)

    Dingenen, Bart; Janssens, Luc; Luyckx, Thomas; Claes, Steven; Bellemans, Johan; Staes, Filip F

    2015-03-01

    An anterior cruciate ligament injury may lead to deteriorations in postural stability. The goal of this study was to evaluate postural stability during the transition from double-leg stance to single-leg stance of both legs in anterior cruciate ligament injured subjects and non-injured control subjects with a standardized methodology. Fifteen control subjects and 15 anterior cruciate ligament injured subjects (time after injury: mean (SD)=1.4 (0.7) months) participated in the study. Both groups were similar for age, gender, height, weight and body mass index. Spatiotemporal center of pressure outcomes of both legs of each subject were measured during the transition from double-leg stance to single-leg stance in eyes open and eyes closed conditions. Movement speed was standardized. The center of pressure displacement after a new stability point was reached during the single-leg stance phase was significantly increased in the anterior cruciate ligament injured group compared to the control group in the eyes closed condition (Plegs within both groups (P>.05). No significant differences were found during the transition itself (P>.05). The anterior cruciate ligament injured group showed postural stability deficits during the single-leg stance phase compared to the non-injured control group in the eyes closed condition. Using the non-injured leg as a normal reference when evaluating postural stability of the injured leg may lead to misinterpretations, as no significant differences were found between the injured and non-injured leg of the anterior cruciate ligament injured group. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Clinical outcomes and frontal plane two-dimensional biomechanics during the 30-second single leg stance test in patients before and after hip abductor tendon reconstructive surgery.

    Science.gov (United States)

    Huxtable, Rose E; Ackland, Timothy R; Janes, Gregory C; Ebert, Jay R

    2017-07-01

    Hip abductor tendon tears are a common cause of Greater Trochanteric Pain Syndrome. Conservative treatments are often ineffective and surgical reconstruction may be recommended. This study investigated the improvement in clinical outcomes and frontal plane two-dimensional biomechanics during a 30-second single leg stance test, in patients undergoing reconstruction. We hypothesized that clinical scores and pertinent biomechanical variables would significantly improve post-surgery, and these outcomes would be significantly correlated. Twenty-one patients with symptomatic tendon tears underwent reconstruction. Patients were evaluated pre-surgery, and at 6 and 12months post-surgery, using patient-reported outcome measures, assessment of hip abductor strength and six-minute walk capacity. Frontal plane, two-dimensional, biomechanical variables including pelvis-on-femur angle, pelvic drop, trunk lean and lateral pelvic shift, were evaluated throughout a 30-second single leg stance test. ANOVA evaluated outcomes over time, while Pearson's correlations investigated associations between clinical scores, pain, functional and biomechanical outcome variables. While clinical and functional measures significantly improved (P0.05) were observed in biomechanical variables from pre- to post-surgery. While five patients displayed a positive Trendelenburg sign pre-surgery, only one was positive post-surgery. Clinical outcomes and biomechanical variables during the single leg stance test were not correlated. Despite improvements in clinical and functional measures over time, biomechanical changes during a weight bearing single leg stance test were not significantly different following tendon repair. Follow up beyond 12months may be required, whereby symptomatic relief may precede functional and biomechanical improvement. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. The single-leg Roman chair hold is more effective than the Nordic hamstring curl in improving hamstring strength-endurance in Gaelic footballers with previous hamstring injury.

    Science.gov (United States)

    Macdonald, Ben; O'Neill, John; Pollock, Noel; Van Hooren, Bas

    2018-03-06

    Poor hamstring strength-endurance is a risk factor for hamstring injuries. This study investigated the effectiveness of the single-leg Roman hold and Nordic hamstring curl in improving hamstring strength-endurance. Twelve Gaelic footballers (mean ± standard deviation age, height and mass were 25.17 ± 3.46 years, 179.25 ± 5.88 cm, 85.75 ± 4.75 kilo) with a history of hamstring injury were randomized into 2 groups that performed 6 weeks of either Nordic hamstring curl, or single-leg Roman chair hold training. The single-leg hamstring bridge (SLHB) was measured pre- and post- intervention. The Roman chair group showed a very likely moderate magnitude improvement on SLHB performance for both legs (23.7% for the previously injured leg [90% confidence interval 9.6% to 39.6%] and 16.9% for the non-injured leg [6.2% to 28.8%]). The Nordic curl group showed a likely trivial change in SLHB performance for the non-injured leg (-2.1% [-6.7% to 2.6%]) and an unclear, but possibly trivial change for the previously injured leg (0.3% [-5.6% to 6.6%]). The Roman chair group improved very likely more with a moderate magnitude in both the non-injured (19.5% [8.0% to 32.2%]) and the previously injured leg (23.3% [8.5% to 40.0%]) compared to the Nordic curl group. This study demonstrated that 6-weeks single-leg Roman chair training substantially improved SLHB performance, suggesting that it may be an efficacious strategy to mitigate hamstring (re-) injury risk. Conversely, 6-weeks Nordic curl training did not substantially improve SLHB performance, suggesting this may not be the intervention of choice for modifying this risk factor.

  2. Reliability of 3-Dimensional Measures of Single-Leg Cross Drop Landing Across 3 Different Institutions: Implications for Multicenter Biomechanical and Epidemiological Research on ACL Injury Prevention.

    Science.gov (United States)

    DiCesare, Christopher A; Bates, Nathaniel A; Barber Foss, Kim D; Thomas, Staci M; Wordeman, Samuel C; Sugimoto, Dai; Roewer, Benjamin D; Medina McKeon, Jennifer M; Di Stasi, Stephanie; Noehren, Brian W; Ford, Kevin R; Kiefer, Adam W; Hewett, Timothy E; Myer, Gregory D

    2015-12-01

    Anterior cruciate ligament (ACL) injuries are physically and financially devastating but affect a relatively small percentage of the population. Prospective identification of risk factors for ACL injury necessitates a large sample size; therefore, study of this injury would benefit from a multicenter approach. To determine the reliability of kinematic and kinetic measures of a single-leg cross drop task across 3 institutions. Controlled laboratory study. Twenty-five female high school volleyball players participated in this study. Three-dimensional motion data of each participant performing the single-leg cross drop were collected at 3 institutions over a period of 4 weeks. Coefficients of multiple correlation were calculated to assess the reliability of kinematic and kinetic measures during the landing phase of the movement. Between-centers reliability for kinematic waveforms in the frontal and sagittal planes was good, but moderate in the transverse plane. Between-centers reliability for kinetic waveforms was good in the sagittal, frontal, and transverse planes. Based on these findings, the single-leg cross drop task has moderate to good reliability of kinematic and kinetic measures across institutions after implementation of a standardized testing protocol. Multicenter collaborations can increase study numbers and generalize results, which is beneficial for studies of relatively rare phenomena, such as ACL injury. An important step is to determine the reliability of risk assessments across institutions before a multicenter collaboration can be initiated.

  3. A rare knee extensor mechanism injury: Vastus intermedius tendon rupture

    Directory of Open Access Journals (Sweden)

    Engin Cetinkaya

    2015-01-01

    Conclusion: We report the first case of isolated rupture of the vastus intermedius tendon in the literature and we claim that disorder may be succesfully treated with conservative treatment and adequate physiotheraphy.

  4. Influence of visual feedback on knee extensor isokinetic concentric ...

    African Journals Online (AJOL)

    Isokinetic normative data can be invaluable in identifying an individual's strengths and weaknesses, and thus lead to a more effective use of the individual's time to minimise or overcome his weaknesses while maintaining or improving existing strength. However, visual feedback (VF) may significantly affect the result of ...

  5. Carryover effect of hip and knee exercises program on functional performance in individuals with patellofemoral pain syndrome.

    Science.gov (United States)

    Ahmed Hamada, Hamada; Hussein Draz, Amira; Koura, Ghada Mohamed; Saab, Ibtissam M

    2017-08-01

    [Purpose] This study was carried out to investigate the carryover effect of hip and knee exercises program on functional performance (single legged hop test as functional performance test and Kujala score for functional activities). [Subjects and Methods] Thirty patients with patellofemoral pain syndrome were randomly assigned into two equal groups. Group (A) consisted of 15 patients undergoing hip strengthening exercises for four weeks then measuring all variables followed by additional four weeks of knee exercises program then measuring all variables again. Group (B): consisted of 15 patients undergoing knee exercises program for four weeks then measuring all variables followed by additional four weeks of hip strengthening exercises then measuring all variables. Functional abilities and knee muscles performance were assessed using Kujala questionnaire and single legged hop test respectively pre and after the completion of the first 4 weeks then after 8 weeks for both groups. [Results] Significantly increase in Kujala questionnaire in group A compared with group B was observed. While, there were significant increase in single legged hop performance test in group B compared with group A. [Conclusion] Starting with hip exercises improve the performance of subjects more than functional activities while starting with knee exercises improve the functional activities of subjects more than performance.

  6. Selected isokinetic tests in knee injury prevention

    Directory of Open Access Journals (Sweden)

    W Pilis

    2010-03-01

    Full Text Available Ensuing from isokinetic measurements, the conventional Hcon/Qcon ratio of muscle balance is used as an index for comparing proper relations between the values of strength of knee flexors and extensor muscle. Its abnormal values might indicate pathology of the musculotendinous complex. The aim of the study was to present the possibility of using this ratio as one of the objective identifiers enabling the assessment of knee injury risk in sports. All participants (n=48 were divided into 3 groups: group A (n=16, healthy competitors, group B (n=16, athletes with minor injuries, group C (n=16, competitors with serious injuries, depending on the degree of knee injury. All subjects performed an isokinetic test for knee extensors and flexors at angular velocities of 60°/s and 120°/s. Average peak torque (APT value of knee flexors and extensors, and the value of Hcon/Qcon ratio was analyzed. Both values were calculated in relation to body mass (Nm/kg. Bilateral comparison of isokinetic test parameters confirmed the decrease of quadriceps muscle strength values for the injured extremity in groups B and C. Statistically significant difference was noted for Hcon/Qcon ratio between group A and C, as well as B and C. Hence, the value of conventional Hcon/Qcon ratio can be used for the prevention of sports related injuries.

  7. Subjective vs objective predictors of functional knee joint performance in anterior cruciate ligament-reconstructed patients

    DEFF Research Database (Denmark)

    Holsgaard-Larsen, Anders; Jensen, Carsten; Aagaard, Per

    2014-01-01

    BACKGROUND: Associations between objective and subjective measures of knee function may facilitate rehabilitation in ACL-patients. AIM: The aim of this study is to investigate if a test-battery of functional and/or muscle outcomes are associated with Knee osteoarthritis outcome score (KOOS......) one-leg maximal jump for distance (OLJD), isometric maximal voluntary contraction (MVC) for (ii) knee extensors and (iii) flexors, and (iv) maximal counter movement jump (CMJ). Sagittal kinematic data were recorded during CMJ using a 6-camera Vicon MX system. Multilevel linear regression analysis.......01) were observed (Model 1). Adding knee extensor or flexor MVC to the analysis (Model 2) increased the strength of the associations (up to r(2)=0.53, pknee extensor and knee flexor MVC to the analysis (Model 3) did not improve...

  8. Fatigue effects on knee joint stability during two jump tasks in women.

    Science.gov (United States)

    Ortiz, Alexis; Olson, Sharon L; Etnyre, Bruce; Trudelle-Jackson, Elaine E; Bartlett, William; Venegas-Rios, Heidi L

    2010-04-01

    Dynamic knee joint stability may be affected by the onset of metabolic fatigue during sports participation that could increase the risk for knee injury. The purpose of this investigation was to determine the effects of metabolic fatigue on knee muscle activation, peak knee joint angles, and peak knee internal moments in young women during 2 jumping tasks. Fifteen women (mean age: 24.6 +/- 2.6 years) participated in one nonfatigued session and one fatigued session. During both sessions, peak knee landing flexion and valgus joint angles, peak knee extension and varus/valgus internal moments, electromyographic (EMG) muscle activity of the quadriceps and hamstrings, and quadriceps/hamstring EMG cocontraction ratio were measured. The tasks consisted of a single-legged drop jump from a 40-cm box and a 20-cm, up-down, repeated hop task. The fatigued session included a Wingate anaerobic protocol followed by performance of the 2 tasks. Although participants exhibited greater knee injury-predisposing factors during the fatigued session, such as lesser knee flexion joint angles, greater knee valgus joint angles, and greater varus/valgus internal joint moments for both tasks, only knee flexion during the up-down task was statistically significant (p = 0.028). Metabolic fatigue may perhaps predispose young women to knee injuries by impairing dynamic knee joint stability. Training strength-endurance components and the ability to maintain control of body movements in either rested or fatigued situations might help reduce injuries in young women athletes.

  9. Landing Kinematics and Kinetics at the Knee During Different Landing Tasks.

    Science.gov (United States)

    Heebner, Nicholas R; Rafferty, Deirdre M; Wohleber, Meleesa F; Simonson, Andrew J; Lovalekar, Mita; Reinert, Andrew; Sell, Timothy C

    2017-12-01

      Several tasks have been used to examine landing biomechanics for evaluation and rehabilitation, especially as related to anterior cruciate ligament injuries. However, comparing results among studies in which different tasks were used can be difficult, and it is unclear which task may be most appropriate.   To compare lower extremity biomechanics across 5 commonly used landing tasks.   Descriptive laboratory study.   University-operated US Air Force Special Operations Forces human performance research laboratory.   A total of 65 US Air Force Special Tactics Operators (age = 27.7 ± 5.0 years, height = 176.5 ± 5.7 cm, mass = 83.1 ± 9.1 kg).   Kinematic and kinetic analysis of double- and single-legged drop landing, double- and single-legged stop jump, and forward jump to single-legged landing.   Hip-, knee-, and ankle-joint kinematics; knee-joint forces and moments; and ground reaction forces (GRFs) were the dependent measures. We used repeated-measures analyses of variance or Friedman tests, as appropriate, to assess within-subject differences across tasks.   Peak vertical GRF and peak knee-flexion angle were different among all tasks ( P tasks elicited different biomechanical responses; no single task was best for assessing a wide range of biomechanical variables related to anterior cruciate ligament injuries. Therefore, depending on the goals of the study, using multiple assessment tasks should be considered.

  10. Spine buddy® supportive pad impact on single-leg static balance and a jogging gait of individuals wearing a military backpack.

    Science.gov (United States)

    Ward, John; Coats, Jesse; Pourmoghaddam, Amir

    2014-12-09

    The Spine Buddy® supportive pad was developed to be inserted underneath military backpacks to help disperse the heavy load of the backpack. The purpose of this study was to determine the impact the additional supportive pad had on static balance and a running gait while wearing a military backpack. Forty healthy subjects (age= 27.5 + 5.6 yrs, body height= 1.78 + 0.06 m, body mass= 86.5 + 14.0 kg: mean + SD) participated in a static single-leg balance test on a force plate with each lower limb while wearing a 15.9 kg military backpack for 30 s. Following this, participants were randomized to one of two interventions: 1) Intervention, which wore the Spine Buddy® supportive pad underneath their backpack or 2) Control, with no additional supportive pad. Post-intervention measurements of static single-leg balance were then recorded. Afterwards, a similar pre vs post testing schedule and randomization scheme was used to test the impact of the supportive pad on a 5 mph jogging gait using Vicon® cameras. Within-group data were analyzed with a 2-way repeated measures ANOVA. Statistically significant differences were not seen between the control and experimental group for balance and gait variables. Preliminarily, this suggests that the Spine Buddy® supportive pad causes no deleterious effect on static balance and a jogging gait in 18-45 year-old asymptomatic individuals.

  11. Spine Buddy® Supportive Pad Impact on Single-Leg Static Balance and a Jogging Gait of Individuals Wearing a Military Backpack

    Directory of Open Access Journals (Sweden)

    Ward John

    2014-12-01

    Full Text Available The Spine Buddy® supportive pad was developed to be inserted underneath military backpacks to help disperse the heavy load of the backpack. The purpose of this study was to determine the impact the additional supportive pad had on static balance and a running gait while wearing a military backpack. Forty healthy subjects (age= 27.5 + 5.6 yrs, body height= 1.78 + 0.06 m, body mass= 86.5 + 14.0 kg: mean + SD participated in a static single-leg balance test on a force plate with each lower limb while wearing a 15.9 kg military backpack for 30 s. Following this, participants were randomized to one of two interventions: 1 Intervention, which wore the Spine Buddy® supportive pad underneath their backpack or 2 Control, with no additional supportive pad. Post-intervention measurements of static single-leg balance were then recorded. Afterwards, a similar pre vs post testing schedule and randomization scheme was used to test the impact of the supportive pad on a 5 mph jogging gait using Vicon® cameras. Within-group data were analyzed with a 2-way repeated measures ANOVA. Statistically significant differences were not seen between the control and experimental group for balance and gait variables. Preliminarily, this suggests that the Spine Buddy® supportive pad causes no deleterious effect on static balance and a jogging gait in 18-45 year-old asymptomatic individuals.

  12. Four Weeks in a Single-Leg Weight-Bearing Hip Spica Cast is Sufficient Treatment for Isolated Femoral Shaft Fractures in Children Aged 1 to 3 Years.

    Science.gov (United States)

    Jaafar, Sami; Sobh, Ali; Legakis, Julie E; Thomas, Ronald; Buhler, Kelsey; Jones, Eric T

    2016-01-01

    Hip spica casting regimens for the treatment of femoral shaft fractures in a pediatric population aged 1 to 3 years vary. Patient charts were reviewed to determine if there are any clinical differences between 3 and 4 weeks in an ambulatory single-leg hip spica (SLHS) cast versus 6 to 8 weeks in a standard double-leg, non-weight-bearing hip spica cast. The medical records of 109 patients with femoral shaft fractures treated with a hip spica casting from January 1, 2008 to December 31, 2011 were examined. After exclusions, 94 patients were eligible for inclusion in the study. Patient records were assessed, noting age, weight, type of cast, time in cast, and complications. All casts were applied by senior pediatric orthopaedic surgeons at a single institution. Two groups were evaluated: 59 patients in the SLHS group and 35 in the double-leg hip spica group. The 2 groups were demographically similar with an average age of 2 years, 70.2% of patients were male, 45.7% were black, and 35.1% were white. The average time to cast removal was 4.1 weeks for the single-leg group and 5.3 weeks for the double-leg group (Pshaft fractures in patients less than 4 years old can be treated in a weight-bearing SLHS casts for approximately 4 weeks with fewer alignment and skin complications. Level III-clinical retrospective comparative study.

  13. A comparison of ballet dancers with different level of experience in performing single-leg stance on retiré position.

    Science.gov (United States)

    Lin, Chia-Wei; Lin, Cheng-Feng; Hsue, Bih-Jen; Su, Fong-Chin

    2014-04-01

    The purpose of the current study was to evaluate the postural stability of single-leg standing on the retiré position in ballet dancers having three different levels of skill. Nine superior experienced female ballet dancers, 9 experienced, and 12 novice dancers performed single-leg standing in the retiré position. The parameters of center of pressure (COP) in the anterior-posterior and medial-lateral directions and the maximum distance between COP and the center of mass (COM) were measured. The inclination angles of body segments (head, torso, and supporting leg) in the frontal plane were also calculated. The findings showed that the novice dancers had a trend of greater torso inclination angles than the experienced dancers but that the superior experienced dancers had greater maximum COM-COP distance in the anterior-posterior direction. Furthermore, both experienced and novice dancers had better balance when standing on the nondominant leg, whereas the superior experienced dancers had similar postural stability between legs. Based on the findings, ballet training should put equal focus on both legs and frontal plane control (medial-lateral direction) should be integrated to ballet training program.

  14. Single-leg drop landing movement strategies in participants with chronic ankle instability compared with lateral ankle sprain 'copers'.

    Science.gov (United States)

    Doherty, Cailbhe; Bleakley, Chris; Hertel, Jay; Caulfield, Brian; Ryan, John; Delahunt, Eamonn

    2016-04-01

    To compare the movement patterns and underlying energetics of individuals with chronic ankle instability (CAI) to ankle sprain 'copers' during a landing task. Twenty-eight (age 23.2 ± 4.9 years; body mass 75.5 ± 13.9 kg; height 1.7 ± 0.1 m) participants with CAI and 42 (age 22.7 ± 1.7 years; body mass 73.4 ± 11.3 kg; height 1.7 ± 0.1 m) ankle sprain 'copers' were evaluated 1 year after incurring a first-time lateral ankle sprain injury. Kinematics and kinetics of the hip, knee and ankle joints from 200 ms pre-initial contact (IC) to 200 ms post-IC, in addition to the vertical component of the landing ground reaction force, were acquired during performance of a drop land task. The CAI group adopted a position of increased hip flexion during the landing descent on their involved limb. This coincided with a reduced post-IC flexor pattern at the hip and increased overall hip joint stiffness compared to copers (-0.01 ± 0.05 vs. 0.02 ± 0.05°/Nm kg(-1), p = 0.03). Individuals with CAI display alterations in hip joint kinematics and energetics during a unipodal landing task compared to LAS 'copers'. These alterations may be responsible for the increased risk of injury experienced by individuals with CAI during landing manoeuvres. Thus, clinicians must recognise the potential for joints proximal to the affected ankle to contribute to impaired function following an acute lateral ankle sprain injury and to develop rehabilitation protocols accordingly. Level III.

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

    Science.gov (United States)

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

    2014-01-01

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

  16. REHABILITATATION FOR EXTENSOR HALLUCIS LONGUS AND EXTENSOR DIGITORUM LONGUS TENDINOPATHY – AN EXERCISE PACKAGE

    OpenAIRE

    Oskar, Sten

    2016-01-01

    The purpose of this thesis was to create an exercise package containing research proven evidence based exercises for Extensor Hallucis Longus and Extensor Digitorum Longus muscles for strengthening purposes. The exercise package consists of eccen-tric exercises that have been proven to be beneficial in treating tendon problems. The exercise package will be provided to be implemented by the players and coaches of the co-operating bandy team. The thesis was done in collaboration with Pori N...

  17. KNEE-JOINT LOADING IN KNEE OSTEOARTHRITIS: INFLUENCE OF ABDOMINAL AND THIGH FAT

    Science.gov (United States)

    Messier, Stephen P.; Beavers, Daniel P.; Loeser, Richard F.; Carr, J. Jeffery; Khajanchi, Shubham; Legault, Claudine; Nicklas, Barbara J.; Hunter, David J.; DeVita, Paul

    2014-01-01

    Purpose Using three separate models that included total body mass, total lean and total fat mass, and abdominal and thigh fat as independent measures, we determined their association with knee-joint loads in older overweight and obese adults with knee osteoarthritis (OA). Methods Fat depots were quantified using computed tomography and total lean and fat mass determined with dual energy x-ray absorptiometry in 176 adults (age = 66.3 yr., BMI = 33.5 kg·m−2) with radiographic knee OA. Knee moments and joint bone-on-bone forces were calculated using gait analysis and musculoskeletal modeling. Results Higher total body mass was significantly associated (p ≤ 0.0001) with greater knee compressive and shear forces, compressive and shear impulses (p knee extensor moments (p = 0.003). Regression analysis with total lean and total fat mass as independent variables revealed significant positive associations of total fat mass with knee compressive (p = 0.0001), shear (p knee extension moment (p = 0.008). Gastrocnemius and quadriceps forces were positively associated with total fat mass. Total lean mass was associated with knee compressive force (p = 0.002). A regression model that included total thigh and total abdominal fat found both were significantly associated with knee compressive and shear forces (p ≤ 0.04). Thigh fat was associated with the knee abduction (p = 0.03) and knee extension moment (p = 0.02). Conclusions Thigh fat, consisting predominately of subcutaneous fat, had similar significant associations with knee joint forces as abdominal fat despite its much smaller volume and could be an important therapeutic target for people with knee OA. PMID:25133996

  18. Strength deficits identified with concentric action of the hip extensors and eccentric action of the hamstrings predispose to hamstring injury in elite sprinters.

    Science.gov (United States)

    Sugiura, Yusaku; Saito, Tomoyuki; Sakuraba, Keishoku; Sakuma, Kazuhiko; Suzuki, Eiichi

    2008-08-01

    Prospective cohort study. In this prospective cohort study of elite sprinters, muscle strength of the hip extensors, as well as of the knee extensors and flexors, was measured to determine a possible relationship between strength deficits and subsequent hamstring injury within 12 months of testing. The method used for testing muscle strength simulated the specific muscle action during late swing and early contact phases when sprinting. There have been no prospective studies in elite sprinters that examine the concentric and eccentric isokinetic strength of the hip extensors and the quadriceps and hamstring muscles in a manner that reflects their actions in late swing or early contact phases of sprinting. Consequently, the causal relationship between hip and thigh muscle strength and hamstring injury in elite sprinters may not be fully understood. Isokinetic testing was performed on 30 male elite sprinters to assess hip extensors, quadriceps, and hamstring muscle strength. The occurrence of hamstring injury among the subjects was determined during the year following the muscle strength measurements. The strength of the hip extensors, quadriceps, and hamstring muscles, as well as the hamstrings-quadriceps and hip extensors- quadriceps ratios were compared. Hamstring injury occurred in 6 subjects during the 1-year period. Isokinetic testing at a speed of 60 degrees /s revealed weakness of the injured limb with eccentric action of the hamstring muscles and during concentric action of the hip extensors. When performing a side-to-side comparison for the injured sprinters, the hamstring injury always occurred on the weaker side. Differences in the hamstrings-quadriceps and hip extensors-quadriceps strength ratios were also evident between uninjured and injured limbs, and this was attributable to deficits in hamstring strength. Hamstring injury in elite sprinters was associated with weakness during eccentric action of the hamstrings and weakness during concentric action of

  19. Gait and balance of transfemoral amputees using passive mechanical and microprocessor-controlled prosthetic knees.

    Science.gov (United States)

    Kaufman, K R; Levine, J A; Brey, R H; Iverson, B K; McCrady, S K; Padgett, D J; Joyner, M J

    2007-10-01

    Microprocessor-controlled knee joints appeared on the market a decade ago. These joints are more sophisticated and more expensive than mechanical ones. The literature is contradictory regarding changes in gait and balance when using these sophisticated devices. This study employed a crossover design to assess the comparative performance of a passive mechanical knee prosthesis compared to a microprocessor-controlled knee joint in 15 subjects with an above-knee amputation. Objective measurements of gait and balance were obtained. Subjects demonstrated significantly improved gait characteristics after receiving the microprocessor-controlled prosthetic knee joint (pknee to a flexed knee during loading response which resulted in a change from an internal knee flexor moment to a knee extensor moment. The participants' balance also improved (pmicroprocessor-controlled knee have significant improvements in gait and balance.

  20. [Isokinetic profile of knee muscles in Tunisian competitive footballers].

    Science.gov (United States)

    Ksibi, Imene; Kessomtini, Wassia; Ilehi, Youssef; Maaoui, Rim; Rahali Khachlouf, Hajer

    2015-05-01

    During football several joints are greatly demanded, especially the knees.The interest of the isokinetic is to detect an imbalance between agonist and antagonist muscles of the muscle leg and between dominant and non dominant leg, in order to prevent injuries and to improve the physical fitness of young soccer players. evaluate the isokinetic profile of flexor and extensor muscles of the knee of competitive footballers Methods : Prospective study conducted in the department of Physical and Rehabilitation Medicine of the Military Tunis Hospital, including 15 competitive footballers and evaluated during the month of August 2012. All patients underwent an isokinetic assessment of agonist and antagonist muscles of the knees in concentric mode 3 speed 60 ° / 120 ° and 180 ° (with analysis of figures and curves), using a Biodex dynamometer. The selected parameters were the time of maximum force (MFM) of the knee flexors and extensors, and the agonists / antagonists ratio (IJ / Q). The data were analyzed by SPSS software. 15 competitive footballers were included. The average age is 23.20 years ± 3.99 years, ranging from 18 to 28 years. The average size is 167.13 cm ± 3.6 cm with a range of 163 and 172 cm. The average weight is 60.87 kg ± 5.97 with a range of 50 to 70 kg. The isokinetic evaluation showed a statistically significant superiority of the flexor muscles of the right knee compared with those of the left knee at the speed 60 / s (p = 0.046) and 120 / s (p = 0.031), whereas this difference has not been found for the extensors muscles. The values of the ratio of quadriceps to hamstring increases with the speed of movement performed, the maximum moment / weight moving in the opposite direction. The isokinetic evaluation allows an objective assessment of the flexor and extensor muscles of the knee footballers, in order to correct imbalance and preserve the sporting future of the young footballers.

  1. Influence of knee joint angle on muscle properties of paralyzed and nonparalyzed human knee extensors

    NARCIS (Netherlands)

    Gerrits, K.H.L.; Maganaris, C.N.; Reeves, N.D.; Sargeant, A.J.; Jones, D.A.; de Haan, A.

    2005-01-01

    Muscles of individuals with a spinal cord injury (SCI) exhibit an unexpected leftward shift in the force (torque)-frequency relationship. We investigated whether differences in torque-angle relationships between SCI and able-bodied control muscles could explain this shift. Electrically stimulated

  2. Is impaired knee confidence related to worse kinesiophobia, symptoms, and physical function in people with knee osteoarthritis after anterior cruciate ligament reconstruction?

    Science.gov (United States)

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

    2015-09-01

    To compare knee confidence and kinesiophobia (fear of re-injury) in those with and without knee osteoarthritis following anterior cruciate ligament reconstruction, and determine whether poorer knee confidence is associated with greater kinesiophobia, worse knee-related symptoms, and functional impairments in those with knee osteoarthritis. Cross-sectional. Sixty-six individuals, 5-12 years following anterior cruciate ligament reconstruction, with (n=30) and without (n=36) knee osteoarthritis were included. Knee injury and Osteoarthritis Outcome Score quality-of-life question (Q3), assessed knee confidence and Tampa Scale of Kinesiophobia assessed kinesiophobia. In the osteoarthritis group, knee-related symptoms (International Knee Documentation Committee and Anterior Knee Pain Scale), self-reported function (Knee injury and Osteoarthritis Outcome Score activities daily living), sport/recreation (Knee injury and Osteoarthritis Outcome Score-sport and recreation), and performance-based function (hopping, one leg rise tasks) were assessed. Between-group differences in knee confidence and kinesiophobia were evaluated with the Chi square test and analysis of variance, respectively. In the osteoarthritis group, between-group differences (none, mild/moderate and severe/extreme problems with knee confidence) in kinesiophobia, symptoms and function were determined with analysis of variances: pconfidence (p=0.010) and greater kinesiophobia (p=0.006) than those without osteoarthritis. In those with knee osteoarthritis, poorer knee confidence was significantly associated with worse symptoms (Anterior Knee Pain Scale, p=0.001; International Knee Documentation Committee, p<0.001), kinesiophobia (p=0.030), Knee injury and Osteoarthritis Outcome Score-activities of daily living (p=0.005), Knee injury and Osteoarthritis Outcome Score-sport and recreation (p=0.001), single-leg hop (p=0.011), side-to-side hop (p=0.013) and one leg rise (p=0.001). Psychological impairments are evident

  3. The effect of accounting for biarticularity in hip flexor and hip extensor joint torque representations.

    Science.gov (United States)

    Lewis, M G C; Yeadon, M R; King, M A

    2018-02-01

    Subject-specific torque-driven models have ignored biarticular effects at the hip. The aim of this study was to establish the contribution of monoarticular hip flexors and hip extensors to total hip flexor and total hip extensor joint torques for an individual and to investigate whether torque-driven simulation models should consider incorporating biarticular effects at the hip joint. Maximum voluntary isometric and isovelocity hip flexion and hip extension joint torques were measured for a single participant together with surface electromyography. Single-joint and two-joint representations were fitted to the collected torque data and used to determine the maximum voluntary joint torque capacity. When comparing two-joint and single-joint representations, the single-joint representation had the capacity to produce larger maximum voluntary hip flexion torque (larger by around 9% of maximum torque) and smaller maximum voluntary hip extension torque (smaller by around 33% of maximum torque) with the knee extended. Considering the range of kinematics found for jumping movements, the single-joint hip flexors had the capacity to produce around 10% additional torque, while the single joint hip extensors had about 70% of the capacity of the two-joint representation. Two-joint representations may overcome an over-simplification of single-joint representations by accounting for biarticular effects, while building on the strength of determining subject-specific parameters from measurements on the participant. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Comparison of a laboratory grade force platform with a Nintendo Wii Balance Board on measurement of postural control in single-leg stance balance tasks.

    Science.gov (United States)

    Huurnink, Arnold; Fransz, Duncan P; Kingma, Idsart; van Dieën, Jaap H

    2013-04-26

    Training and testing of balance have potential applications in sports and medicine. Laboratory grade force plates (FP) are considered the gold standard for the measurement of balance performance. Measurements in these systems are based on the parameterization of center of pressure (CoP) trajectories. Previous research validated the inexpensive, widely available and portable Nintendo Wii Balance Board (WBB). The novelty of the present study is that FP and WBB are compared on CoP data that was collected simultaneously, by placing the WBB on the FP. Fourteen healthy participants performed ten sequences of single-leg stance tasks with eyes open (EO), eyes closed (EC) and after a sideways hop (HOP). Within trial comparison of the two systems showed small root-mean-square differences for the CoP trajectories in the x and y direction during the three tasks (mean±SD; EO: 0.33±0.10 and 0.31±0.16 mm; EC: 0.58±0.17 and 0.63±0.19 mm; HOP: 0.74±0.34 and 0.74±0.27 mm, respectively). Additionally, during all 420 trials, comparison of FP and WBB revealed very high Pearson's correlation coefficients (r) of the CoP trajectories (x: 0.999±0.002; y: 0.998±0.003). A general overestimation was found on the WBB compared to the FP for 'CoP path velocity' (EO: 5.3±1.9%; EC: 4.0±1.4%; HOP: 4.6±1.6%) and 'mean absolute CoP sway' (EO: 3.5±0.7%; EC: 3.7±0.5%; HOP: 3.6±1.0%). This overestimation was highly consistent over the 140 trials per task (r>0.996). The present findings demonstrate that WBB is sufficiently accurate in quantifying CoP trajectory, and overall amplitude and velocity during single-leg stance balance tasks. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Malignant Fibrohisticytoma of the Knee in a Patient with HIV

    Directory of Open Access Journals (Sweden)

    Riccardo Gomes Gobbi

    2012-01-01

    Full Text Available This case report describes a patient presenting with anterior knee pain (extensor mechanism pain, a poorly studied complaint in the HIV population. The final diagnosis was malignant fibrohistiocytoma, a rare condition among knee pathologies, successfully treated with endoprosthesis after tumor resection. This article focuses on what the authors learned after treating this patient, particularly on the difficulty in making a correct diagnosis of this group of patients due to lack of adequate epidemiological characterization. By assuming that the pathology was related to long-term infection and treatment of HIV (knee hoffitis, the authors underestimated the gravity of the case, almost compromising the result of treatment.

  6. Bilateral assessment of knee muscle relationships in healthy adults

    Directory of Open Access Journals (Sweden)

    Gislaine Regina Santos dos Santos

    2014-09-01

    Full Text Available Asymmetric performance of flexor and extensor muscles of the knee may be a risk factor for knee injuries, especially the anterior cruciate ligament. Additionally, asymmetries in power and work may have correlations with fatigue and performance during functional tasks. Among untrained individuals, such asymmetries may be of potential interest for training prescription. Here, we investigated the bilateral performance of knee flexors and extensors muscle groups of untrained individuals. We quantified the torque-angle and torque-velocity relationships, as well as work, power and asymmetry indexes in 20 untrained male (25 ± 4 years old; height 1.74 ± 0.05 m; body mass 76 ± 9 kg. No significant asymmetry was observed for torque-angle and torque-velocity relationships, work and power output for knee flexor and extensor muscle groups (p < .05. Our results suggest that untrained male present symmetry in the knee flexion and extension bilateral performance. Changes in this behavior due to physical training must be monitored.

  7. Rerouting extensor pollicis longus tendon transfer.

    Science.gov (United States)

    Colantoni Woodside, Julie; Bindra, Randip R

    2015-04-01

    Following radial nerve palsy, loss of the extensor pollicis longus (EPL), abductor pollicis longus and extensor pollicis brevis tendons results in loss of thumb extension and radial abduction. Multiple tendon transfers are described to address the loss of thumb extension following radial palsy utilizing the palmaris longus or flexor digitorum sublimis transferred to the EPL tendon. Owing to its ulnar vector of pull, the EPL tendon is a secondary adductor of the thumb, and in order to mitigate the tendency for thumb adduction, the EPL tendon is divided at the wrist and brought subcutaneously to the radial side of the wrist for repair to the donor tendon to improve the line of pull for the donor tendon. We describe the use of a technique to reroute the EPL tendon through the first compartment in a retrograde fashion prior to repair with the donor tendon on the radial side of the wrist. The use of the first dorsal compartment provides a pulley to maintain the position of the transfer and to prevent potential bowstringing of the tendon as wrist flexion and thumb extension are attempted. because the repair is performed proximal to the extensor retinaculum, the donor tendon length is not compromised. Because the tendon is redirected through the first dorsal compartment and inserts into the distal phalanx, a single transfer attempts to restores both thumb extension and radial abduction. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  8. The functional demand (FD) placed on the knee and hip of older adults during everyday activities.

    Science.gov (United States)

    Samuel, Dinesh; Rowe, Philip; Nicol, Alexander

    2013-01-01

    Age-related decline in physical capacity and diminishing physiological reserves may increase the demand placed on lower extremity joints during everyday activities. This study aimed to characterize the FD at the knee and hip joints of older adults during various mobility activities. Eighty-four healthy participants (60-88 years) performed strength tests using a custom-built dynamometer. Biomechanical assessment of gait, chair rise (CR) and sit-down (CSt), stair ascent (SA) and descent (SD) was performed using an 8-camera VICON system (120Hz) and Kistler force plates. Comparisons between groups (60s, 70s and 80s) were made using ANOVA. The FD was defined as the muscle moment generated during a task, divided by the maximum isometric strength (expressed as a percentage). FD was higher in the 80s age group compared to those in the 60s. The demand on hip and knee extensors was normally higher than those of flexors across all the activities. The knee extensor demand during gait (101%), SA (103%) and SD (120%), and hip extensor demand during gait (127%) were high requiring moments in excess of the maximum isometric muscle strength available at these joints. FD during CR and CSt was comparatively lower with knee extensor demands of 73% and 69% and hip extensor demands of 88% and 51%, respectively. Gait, SA and SD placed high demands on the knee extensors while hip extensor demand was high for gait, CR, CSt and SA. The levels of demand leave little reserve capacity for the older adult to draw on in unexpected circumstances. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  9. Altered lower extremity joint mechanics occur during the star excursion balance test and single leg hop after ACL-reconstruction in a collegiate athlete.

    Science.gov (United States)

    Samaan, Michael A; Ringleb, Stacie I; Bawab, Sebastian Y; Greska, Eric K; Weinhandl, Joshua T

    2018-03-15

    The effects of ACL-reconstruction on lower extremity joint mechanics during performance of the Star Excursion Balance Test (SEBT) and Single Leg Hop (SLH) are limited. The purpose of this study was to determine if altered lower extremity mechanics occur during the SEBT and SLH after ACL-reconstruction. One female Division I collegiate athlete performed the SEBT and SLH tasks, bilaterally, both before ACL injury and 27 months after ACL-reconstruction. Maximal reach, hop distances, lower extremity joint kinematics and moments were compared between both time points. Musculoskeletal simulations were used to assess muscle force production during the SEBT and SLH at both time points. Compared to the pre-injury time point, SEBT reach distances were similar in both limbs after ACL-reconstruction except for the max anterior reach distance in the ipsilateral limb. The athlete demonstrated similar hop distances, bilaterally, after ACL-reconstruction compared to the pre-injury time point. Despite normal functional performance during the SEBT and SLH, the athlete exhibited altered lower extremity joint mechanics during both of these tasks. These results suggest that measuring the maximal reach and hop distances for these tasks, in combination with an analysis of the lower extremity joint mechanics that occur after ACL-reconstruction, may help clinicians and researchers to better understand the effects of ACL-reconstruction on the neuromuscular system during the SEBT and SLH.

  10. The Acute Effects of Unilateral Ankle Plantar Flexors Static- Stretching on Postural Sway and Gastrocnemius Muscle Activity During Single-Leg Balance Tasks

    Directory of Open Access Journals (Sweden)

    Bráulio N. Lima, Paulo R.G. Lucareli, Willy A. Gomes, Josinaldo J. Silva, Andre S. Bley, Erin H. Hartigan, Paulo H. Marchetti

    2014-09-01

    Full Text Available The aim of this study was to investigate the acute effects of unilateral ankle plantar flexors static- stretching on surface electromyography (sEMG and the center of pressure (COP during a single-leg balance task in both lower limbs. Fourteen young healthy, non-athletic individuals performed unipodal quiet standing for 30s before and after (stretched limb: immediately post-stretch, 10 and 20 minutes and non-stretched limb: immediately post-stretch a unilateral ankle plantar flexor static- stretching protocol [6 sets of 45s/15s, 70-90% point of discomfort (POD]. Postural sway was described using the COP area, COP speed (antero-posterior and medio-lateral directions and COP frequency (antero-posterior and medio-lateral directions. Surface EMG (EMG integral [IEMG] and Median frequency[FM] was used to describe the muscular activity of gastrocnemius lateralis. Ankle dorsiflexion passive range of motion increased in the stretched limb before and after the static-stretching protocol (mean ± SD: 15.0° ± 6.0 and 21.5° ± 7.0 [p < 0.001]. COP area and IEMG increased in the stretch limb between pre-stretching and immediately post-stretching (p = 0.015 and p = 0.036, respectively. In conclusion, our static- stretching protocol effectively increased passive ankle ROM. The increased ROM appears to increase postural sway and muscle activity; however these finding were only a temporary or transient effect.

  11. Postural stability deficits during the transition from double-leg stance to single-leg stance in anterior cruciate ligament reconstructed subjects.

    Science.gov (United States)

    Dingenen, Bart; Janssens, Luc; Claes, Steven; Bellemans, Johan; Staes, Filip F

    2015-06-01

    The goal of this study was to evaluate postural stability during the transition from double-leg stance (DLS) to single-leg stance (SLS) in anterior cruciate ligament reconstructed (ACLR) (n=20) and non-injured control subjects (n=20). All ACLR subjects had fully returned to their pre-injury sport participation. Both groups were similar for age, gender, height, weight, body mass index and activity level. Spatiotemporal center of pressure outcomes of both legs of each subject were measured during the transition from DLS to SLS in eyes open and eyes closed conditions. Movement speed was standardized. The center of pressure displacement after a new stability point was reached during the SLS phase was significantly increased in the ACLR group compared to the control group in the eyes closed condition (P=.001). No significant different postural stability outcomes were found between the operated and non-operated legs. In conclusion, the ACLR group showed postural stability deficits, indicating that these persons may have a decreased ability to stabilize their body after the internal postural perturbation created by the transition from DLS to SLS. The non-operated leg may not be the best reference when evaluating postural stability of the operated leg after ACLR, as no differences were found between legs. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Volume estimation of extensor muscles of the lower leg based on MR imaging

    International Nuclear Information System (INIS)

    Lund, Hans; Christensen, Line; Savnik, Anette; Danneskiold-Samsoee, Bente; Bliddal, Henning; Boesen, Jens

    2002-01-01

    Magnetic resonance imaging can be used to measure the muscle volume of a given muscle or muscle group. The purpose of this study was to determine both the intra- and inter-observer variation of the manually outlined volume of the extensor muscles (tibialis anterior, extensor digitorum longus and extensor hallucis longus), to estimate the minimum number of slices needed for these calculations and to compare estimates of volume based on an assumed conic shape of the muscles with that of an assumed cylindrical shape, the calculation in both cases based on the Cavalieri principle. Eleven young and healthy subjects (4 women and 7 men, age range 24-40 years) participated. Magnetic resonance imaging of the left leg was obtained on a 1.5-T MR system using a knee coil (receive only). A total of 50 consecutive slices were obtained beginning 10 cm below the caput fibula sin. and proceeding distally with a slice thickness of 1.5 mm without gap. The intra-class correlation coefficient (ICC) was used to calculate the relative reliability (interval from 0 to 1.0). A high reliability for both intra- and inter-reliability was observed (ICC 0.98 and 1.0). The difference was only 0.004% between calculations based on measurement of all 50 slices with respect to 8 slices equally distributed along the muscle group. No difference was found between the two different volumetric assumptions in the Cavalieri principle. The manually outlining of extensor muscles volumes was reliable and only 8 slices of the calf were needed. No difference was seen between the two used mathematical calculations. (orig.)

  13. Volume estimation of extensor muscles of the lower leg based on MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lund, Hans; Christensen, Line; Savnik, Anette; Danneskiold-Samsoee, Bente; Bliddal, Henning [The Parker Institute, Frederiksberg Hospital, 2000 Frederiksberg (Denmark); Boesen, Jens [Department of Radiology, Frederiksberg Hospital, 2000 Frederiksberg (Denmark)

    2002-12-01

    Magnetic resonance imaging can be used to measure the muscle volume of a given muscle or muscle group. The purpose of this study was to determine both the intra- and inter-observer variation of the manually outlined volume of the extensor muscles (tibialis anterior, extensor digitorum longus and extensor hallucis longus), to estimate the minimum number of slices needed for these calculations and to compare estimates of volume based on an assumed conic shape of the muscles with that of an assumed cylindrical shape, the calculation in both cases based on the Cavalieri principle. Eleven young and healthy subjects (4 women and 7 men, age range 24-40 years) participated. Magnetic resonance imaging of the left leg was obtained on a 1.5-T MR system using a knee coil (receive only). A total of 50 consecutive slices were obtained beginning 10 cm below the caput fibula sin. and proceeding distally with a slice thickness of 1.5 mm without gap. The intra-class correlation coefficient (ICC) was used to calculate the relative reliability (interval from 0 to 1.0). A high reliability for both intra- and inter-reliability was observed (ICC 0.98 and 1.0). The difference was only 0.004% between calculations based on measurement of all 50 slices with respect to 8 slices equally distributed along the muscle group. No difference was found between the two different volumetric assumptions in the Cavalieri principle. The manually outlining of extensor muscles volumes was reliable and only 8 slices of the calf were needed. No difference was seen between the two used mathematical calculations. (orig.)

  14. A variation of the extensor hallucis longus muscle (accessory extensor digiti secundus muscle).

    Science.gov (United States)

    Tezer, Murat; Cicekcibasi, Aynur Emine

    2012-06-01

    An accessory muscle adjacent to the extensor hallucis longus muscle (EHL) was observed between the EHL and the extensor digitorum longus muscle (EDL) in the anterior side of both legs of the cadaver of a 72-year-old male, during educational dissection, and it was observed that the tendon of this muscle extended to the second toe. The tendon of this muscle united with the second toe tendon of the EDL. These common tendons appeared before reaching the toe media phalanxes and extended to the related media phalanxes of toe. However, an additional tendon separating from this accessory muscle tendon united with the EHL tendon at the left foot. This accessory muscle, unlike the variations identified to date, is considered to extend to the second toe, and the name "accessory extensor digiti secundus muscle" is offered.

  15. Anterior knee pain

    Energy Technology Data Exchange (ETDEWEB)

    LLopis, Eva [Hospital de la Ribera, Alzira, Valencia (Spain) and Carretera de Corbera km 1, 46600 Alzira Valencia (Spain)]. E-mail: ellopis@hospital-ribera.com; Padron, Mario [Clinica Cemtro, Ventisquero de la Condesa no. 42, 28035 Madrid (Spain)]. E-mail: mario.padron@clinicacemtro.com

    2007-04-15

    Anterior knee pain is a common complain in all ages athletes. It may be caused by a large variety of injuries. There is a continuum of diagnoses and most of the disorders are closely related. Repeated minor trauma and overuse play an important role for the development of lesions in Hoffa's pad, extensor mechanism, lateral and medial restrain structures or cartilage surface, however usually an increase or change of activity is referred. Although the direct relation of cartilage lesions, especially chondral, and pain is a subject of debate these lesions may be responsible of early osteoarthrosis and can determine athlete's prognosis. The anatomy and biomechanics of patellofemoral joint is complex and symptoms are often unspecific. Transient patellar dislocation has MR distinct features that provide evidence of prior dislocation and rules our complication. However, anterior knee pain more often is related to overuse and repeated minor trauma. Patella and quadriceps tendon have been also implicated in anterior knee pain, as well as lateral or medial restraint structures and Hoffa's pad. US and MR are excellent tools for the diagnosis of superficial tendons, the advantage of MR is that permits to rule out other sources of intraarticular derangements. Due to the complex anatomy and biomechanic of patellofemoral joint maltracking is not fully understood; plain films and CT allow the study of malalignment, new CT and MR kinematic studies have promising results but further studies are needed. Our purpose here is to describe how imaging techniques can be helpful in precisely defining the origin of the patient's complaint and thus improve understanding and management of these injuries.

  16. Proprioception after bicruciate-retaining total knee arthroplasty is comparable to unicompartmental knee arthroplasty.

    Science.gov (United States)

    Baumann, Florian; Bahadin, Özkan; Krutsch, Werner; Zellner, Johannes; Nerlich, Michael; Angele, Peter; Tibesku, Carsten Oliver

    2017-06-01

    Rising expectations in functional performance of total knee joints are inciting further improvement of knee arthroplasty implants. From a patient-centred view, bicruciate-retaining models provide a more natural feeling knee. However, there is no evidence of functional advantage for these implants. The aim of this study was to evaluate balance ability as a measure of proprioception in patients with a bicruciate-retaining total knee arthroplasty. A prospective, controlled trial was conducted to compare balance ability in 60 patients after arthroplasty of the knee for osteoarthritis. We compared patients with a bicruciate-retaining knee arthroplasty (BCR group) to a control group of patients with a medial unicompartmental knee arthroplasty (UKA group) and another control group of patients with a posterior stabilized total knee arthroplasty (PS group). The patient population comprised 30 women (50.0 %) and 30 men in three cohorts of 20 each. The mean age was 62.1 ± 8.0 years (range 43-78). Patients were evaluated preoperatively and 9 months post-operatively. The evaluation included clinical, radiological, and balance testing-a single-leg stance with eyes closed compared to eyes open. The difference in area of sway between eyes closed and eyes open represents static balance ability after knee arthroplasty. Perioperative data showed that there was no intra-operative fracture of the intercondylar eminence. There was a decreased post-operative knee extension 9 months post-operative in the BCR group, which was not clinically relevant in any case. We recorded a lower difference in the area of sway between eyes closed and eyes open (ΔA (ec-eo) ) for the BCR group (p = 0.01) and the UKA group (p = 0.04) compared to the PS group. This study found superior static balance ability after preservation of both cruciate ligaments in arthroplasty of the knee, indicating superior proprioceptive function. Hence, BCR implants could provide improved functional properties

  17. Correlation of postural balance and knee muscle strength in the sit-to-stand test among women with and without postmenopausal osteoporosis.

    Science.gov (United States)

    Brech, G C; Alonso, A C; Luna, N M S; Greve, J M

    2013-07-01

    The task of standing up from a chair forms a part of daily life for all independent individuals. However, this task becomes more difficult with advancing age. Women with postmenopausal osteoporosis presented diminished knee extensor and flexor muscle strength. There was a weak correlation between knee muscle strength (greater with extensor strength) and postural balance during the act of standing up. This study aims to evaluate postural balance during the transition from sitting to standing and its relationship with knee extensor and flexor strength among women with and without postmenopausal osteoporosis. Assessments were made on 126 women (aged 55-65 years), divided into osteoporosis and control groups according to lumbar bone density. Their balance during the task of standing up from a chair was evaluated using the Balance Master® device. Knee muscle strength was evaluated using an isokinetic dynamometer (Biodex®), in concentric/concentric mode, at a velocity of 60°/s. Spearman's correlation between the variables of muscle strength and postural balance was evaluated. Subsequently, to evaluate the association of each balance variable with the group and with muscle strength, multiple linear regression models were fitted. The significance level was set at 0.05. There was a difference in knee muscle strength between the groups (P Women with postmenopausal osteoporosis presented diminished knee extensor and flexor muscle strength. There was a weak correlation between knee muscle strength (greater with extensor strength) and postural balance during the act of standing up.

  18. Tendon variations of extensor digitorum and abductor pollicis longus muscles

    OpenAIRE

    Kocabiyik N; Tatar I; Yalcin B; Yazar F; Ozan H

    2009-01-01

    Tendon variations of extensor digitorum and abductor pollicis longus muscles were observed in a 65-year-old male formalin fixed cadaver, during the dissections for second year medical students at the Gulhane Military Medical Academy Anatomy Dissection Laboratory. In the right forearm, the extensor digitorum muscle had a tripled tendon for the 3rd finger and a doubled tendon for the ring finger. The extensor digiti minimi muscle also had a doubled tendon. There was also a communicating tendon ...

  19. A Simulation Model for Extensor Tendon Repair

    Directory of Open Access Journals (Sweden)

    Elizabeth Aronstam

    2017-07-01

    Full Text Available Audience: This simulation model is designed for use by emergency medicine residents. Although we have instituted this at the PGY-2 level of our residency curriculum, it is appropriate for any level of emergency medicine residency training. It might also be adapted for use for a variety of other learners, such as practicing emergency physicians, orthopedic surgery residents, or hand surgery trainees. Introduction: Tendon injuries commonly present to the emergency department, so it is essential that emergency physicians be competent in evaluating such injuries. Indeed, extensor tendon repair is included as an ACGME Emergency Medicine Milestone (Milestone 13, Wound Management, Level 5 – “Performs advanced wound repairs, such as tendon repairs…”.1 However, emergency medicine residents may have limited opportunity to develop these skills due to a lack of patients, competition from other trainees, or preexisting referral patterns. Simulation may provide an alternative means to effectively teach these skills in such settings. Previously described tendon repair simulation models that were designed for surgical trainees have used rubber worms4, licorice5, feeding tubes, catheters6,7, drinking straws8, microfoam tape9, sheep forelimbs10 and cadavers.11 These models all suffer a variety of limitations, including high cost, lack of ready availability, or lack of realism. Objectives: We sought to develop an extensor tendon repair simulation model for emergency medicine residents, designed to meet ACGME Emergency Medicine Milestone 13, Level 5. We wished this model to be simple, inexpensive, and realistic. Methods: The learner responsible content/educational handout component of our innovation teaches residents about emergency department extensor tendon repair, and includes: 1 relevant anatomy 2 indications and contraindications for emergency department extensor tendon repair 3 physical exam findings 4 tendon suture techniques and 5 aftercare. During

  20. Measurement of gliding resistance of the extensor pollicis longus and extensor digitorum communis II tendons within the extensor retinaculum.

    Science.gov (United States)

    Kutsumi, Keiji; Amadio, Peter C; Zhao, Chunfeng; Zobitz, Mark E; An, Kai-Nan

    2004-03-01

    The etiology of spontaneous extensor pollicis longus (EPL) tendon rupture is still largely unknown. It is possible that friction within the sheath may play a role. The purposes of this study were to compare gliding resistance of the EPL tendon with that of the extensor digitorum communis tendon of the index finger (EDC II) and to find the wrist position that gives the EPL tendon the lowest gliding resistance. Fifteen fresh-frozen cadavers were used. Gliding resistance was measured directly in 7 different wrist positions. The mean gliding resistance of the EPL tendon was 0.16 +/- 0.08 N and that of the EDC II tendon was 0.11 +/- 0.06 N. This difference was significant. There was also a significant effect on gliding resistance due to wrist position. For the EPL tendon, the gliding resistance was significantly greater in 60 degrees wrist flexion compared with all other wrist positions tested. Additionally the gliding resistance of the EPL in 30 degrees flexion, 60 degrees extension, and 15 degrees radial deviation was significantly higher than wrist positions of 30 degrees extension, neutral, and 30 degrees ulnar deviation. Positioning the wrist close to neutral flexion/extension and in some ulnar deviation minimizes the friction within the EPL sheath. Such positions may be advantageous for splinting patients at risk for EPL rupture.

  1. Knee Replacement

    Science.gov (United States)

    ... days. Medications prescribed by your doctor should help control pain. During the hospital stay, you'll be encouraged to move your ... exercise your new knee. After you leave the hospital, you'll continue physical ... mobility and a better quality of life. And most knee replacements can be ...

  2. Knee arthroscopy

    Science.gov (United States)

    ... through the other cuts. The surgeon will then fix or remove the problem in your knee. At the end of your surgery, the saline will be drained from your knee. The surgeon will close your cuts with sutures (stitches) and cover them with a dressing. Many surgeons ...

  3. The effectiveness of minimally invasive total knee arthroplasty to preserve quadriceps strength: a randomized controlled trial.

    Science.gov (United States)

    Kim, Jin Goo; Lee, Soo Won; Ha, Jeong Ku; Choi, Hong Joon; Yang, Sang Jin; Lee, Mi Young

    2011-12-01

    We performed a single-center, randomized, double-blind study to compare muscle strength in patients who had undergone primary total knee arthroplasty (TKA), performed using either a minimally invasive or a conventional surgical technique. We evaluated 30 knees in healthy age-matched subjects, 22 knees after conventional TKA (conventional group), and 23 knees after minimally invasive surgery TKA (MIS group). The Hospital for Special Surgery (HSS) score, Oxford knee score (OKS), and isokinetic (60º/s) muscle strength were evaluated the day before surgery and 3, 6, and 12 months after surgery. HSS and OKS improved significantly over time during follow-up (p0.05). The extensor peak torque (EPT) and flexor peak torque (FPT) improved significantly over time (phamstring-to-quadriceps ratio between the groups. Although MIS patients had a significant deficit in extensor strength following TKA, compared with healthy controls, this approach offers a significant improvement in extensor muscle strength over conventional surgery. These results suggest that the MIS approach results in better outcomes with regard to maintaining extensor strength than the conventional surgical approach. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Gait analysis of patients with an off-the-shelf total knee replacement versus customized bi-compartmental knee replacement.

    Science.gov (United States)

    Wang, Henry; Foster, Jonathan; Franksen, Natasha; Estes, Jill; Rolston, Lindsey

    2017-09-04

    Newer TKR designs have been introduced to the market with the aim of overcoming common sizing problems with older TKR designs. Furthermore, since a sizable percentage of patients with OA present with disease limited to the medial/lateral knee compartment in addition to the patellofemoral joint, for whom, a customized bi-compartmental knee replacement (BKR) is available as a treatment option. To date, there is very little information regarding knee strength and mechanics during gait for patients implanted with these modern TKR and BKR designs. The purpose of the study was to evaluate knee strength and mechanics during walking for patients with either a modern off the shelf TKR or a customized BKR and compare these findings to a cohort of healthy controls. Twelve healthy controls, eight BKR, and nine TKR patients participated in the study. Maximal isometric knee strength was evaluated. 3D kinematic and kinetic analyses were conducted for level walking. The TKR knee exhibited less peak extensor torque when compared to, both the BKR and control limbs (p < 0.05). The TKR knee had less extensor moment at stance than both the BKR and control knees (p < 0.05). Both the BKR and control knees displayed larger internal rotation at stance than that of the TKR knee (p < 0.05). This study suggests that, for patients that exhibit isolated OA of the tibiofemoral joint, using a customized BKR implant is a viable treatment option and may contribute to superior mechanical advantages.

  5. The impact of previous knee injury on force plate and field-based measures of balance.

    Science.gov (United States)

    Baltich, Jennifer; Whittaker, Jackie; Von Tscharner, Vinzenz; Nettel-Aguirre, Alberto; Nigg, Benno M; Emery, Carolyn

    2015-10-01

    Individuals with post-traumatic osteoarthritis demonstrate increased sway during quiet stance. The prospective association between balance and disease onset is unknown. Improved understanding of balance in the period between joint injury and disease onset could inform secondary prevention strategies to prevent or delay the disease. This study examines the association between youth sport-related knee injury and balance, 3-10years post-injury. Participants included 50 individuals (ages 15-26years) with a sport-related intra-articular knee injury sustained 3-10years previously and 50 uninjured age-, sex- and sport-matched controls. Force-plate measures during single-limb stance (center-of-pressure 95% ellipse-area, path length, excursion, entropic half-life) and field-based balance scores (triple single-leg hop, star-excursion, unipedal dynamic balance) were collected. Descriptive statistics (mean within-pair difference; 95% confidence intervals) were used to compare groups. Linear regression (adjusted for injury history) was used to assess the relationship between ellipse-area and field-based scores. Injured participants on average demonstrated greater medio-lateral excursion [mean within-pair difference (95% confidence interval); 2.8mm (1.0, 4.5)], more regular medio-lateral position [10ms (2, 18)], and shorter triple single-leg hop distances [-30.9% (-8.1, -53.7)] than controls, while no between group differences existed for the remaining outcomes. After taking into consideration injury history, triple single leg hop scores demonstrated a linear association with ellipse area (β=0.52, 95% confidence interval 0.01, 1.01). On average the injured participants adjusted their position less frequently and demonstrated a larger magnitude of movement during single-limb stance compared to controls. These findings support the evaluation of balance outcomes in the period between knee injury and post-traumatic osteoarthritis onset. Copyright © 2015 Elsevier Ltd. All rights

  6. The effect of proprioceptive knee bracing on knee stability during three different sport related movement tasks in healthy subjects and the implications to the management of Anterior Cruciate Ligament (ACL) injuries.

    Science.gov (United States)

    Hanzlíková, I; Richards, J; Tomsa, M; Chohan, A; May, K; Smékal, D; Selfe, J

    2016-07-01

    Proprioceptive knee braces have been shown to improve knee mechanics, however much of the work to date has focused on tasks such as slow step down tasks rather than more dynamic sporting tasks. This study aimed to explore if such improvements in stability may be seen during faster sports specific tasks as well as slower tasks. Twelve subjects performed a slow step down, single leg drop jump and pivot turn jump with and without a silicone web brace. 3D kinematics of the knee were collected using a ten camera Qualisys motion analysis system. Reflective markers were placed on the foot, shank, thigh and pelvis using the Calibrated Anatomical Systems Technique. A two way ANOVA with repeated measures was performed with post-hoc pairwise comparison to explore the differences between the two conditions and three tasks. Significant differences were seen in the knee joint angles and angular velocities in the sagittal, coronal and transverse planes between the tasks. The brace showed a reduction in knee valgum and internal rotation across all tasks, with the most notable effect during the single leg drop jump and pivot turn jump. The transverse plane also showed a significant reduction in the external rotation knee angular velocity when wearing the brace. The brace influenced the knee joint kinematics in coronal and transverse planes which confirms that such braces can have a significant effect on knee control during dynamic tasks. Further studies are required exploring the efficacy of proprioceptive braces in athletic patient cohort. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Tuberculosis tenosynovitis of the extensor tendons of the wrist

    OpenAIRE

    Mrabet, Dalila; Ouenniche, Kmar; Mizouni, Habiba; Ounaies, Mouna; Khémiri, Chékib; Sahli, Héla; Sellami, Slaheddine

    2011-01-01

    Mycobacterial tuberculous tenosynovitis of the extensor tendon sheath is an extremely rare manifestation of extrapulmonary tuberculosis. The diagnosis may be easily delayed because of its non-specific clinical signs. We report a new case of tuberculous tenosynovitis of the extensor without concomitant pulmonary tuberculosis or documented immunodeficiency.

  8. Effect of generalized joint hypermobility on knee function and muscle activation in children and adults

    DEFF Research Database (Denmark)

    Jensen, Bente Rona; Olesen, Annesofie T.; Pedersen, Mogens Theisen

    2013-01-01

    Introduction: We investigated muscle activation strategy and performance of knee extensor and flexor muscles in children and adults with generalized joint hypermobility (GJH) and compared them with controls. Methods: Muscle activation, torque steadiness, electromechanical delay, and muscle streng......: The results indicate that muscle activation strategy and quality of force control were significantly affected in adults with GJH during knee flexion, whereas only muscle activation strategy was affected in children with GJH. Muscle Nerve, 2013.......Introduction: We investigated muscle activation strategy and performance of knee extensor and flexor muscles in children and adults with generalized joint hypermobility (GJH) and compared them with controls. Methods: Muscle activation, torque steadiness, electromechanical delay, and muscle strength...... were evaluated in 39 children and 36 adults during isometric knee extension and flexion. Subjects performed isometric maximum contractions, submaximal contractions at 25% maximum voluntary contraction (MVC), and explosive contractions. Results: Agonist activation was reduced, and coactivation ratio...

  9. Determining the activation of gluteus medius and the validity of the single leg stance test in chronic, nonspecific low back pain.

    Science.gov (United States)

    Penney, Tracy; Ploughman, Michelle; Austin, Mark W; Behm, David G; Byrne, Jeannette M

    2014-10-01

    To determine the activation of the gluteus medius in persons with chronic, nonspecific low back pain compared with that in control subjects, and to determine the association of the clinical rating of the single leg stance (SLS) with chronic low back pain (CLBP) and gluteus medius weakness. Cohort-control comparison. Academic research laboratory. Convenience sample of people (n=21) with CLBP (>12wk) recruited by local physiotherapists, and age- and sex-matched controls (n=22). Subjects who received specific pain diagnoses were excluded. Not applicable. Back pain using the visual analog scale (mm); back-related disability using the Oswestry Back Disability Index (%); strength of gluteus medius measured using a hand dynamometer (N/kg); SLS test; gluteus medius onset and activation using electromyography during unipedal stance on a forceplate. Individuals in the CLBP group exhibited significant weakness in the gluteus medius compared with controls (right, P=.04; left, P=.002). They also had more pain (CLBP: mean, 20.50mm; 95% confidence interval [CI], 13.11-27.9mm; control subjects: mean, 1.77mm; 95% CI, -.21 to 3.75mm) and back-related disability (CLBP: mean, 18.52%; 95% CI, 14.46%-22.59%; control subjects: mean, .68%; 95% CI, -.41% to 1.77%), and reported being less physically active. Weakness was accompanied by increased gluteus medius activation during unipedal stance (R=.50, P=.001) but by no difference in muscle onset times. Although greater gluteus medius weakness was associated with greater pain and disability, there was no difference in muscle strength between those scoring positive and negative on the SLS test (right: F=.002, P=.96; left: F=.1.75, P=.19). Individuals with CLBP had weaker gluteus medius muscles than control subjects without back pain. Even though there was no significant difference in onset time of the gluteus medius when moving to unipedal stance between the groups, the CLBP group had greater gluteus medius activation. A key finding was that

  10. Two-dimensional motion analysis of dynamic knee valgus identifies female high school athletes at risk of non-contact anterior cruciate ligament injury.

    Science.gov (United States)

    Numata, Hitoaki; Nakase, Junsuke; Kitaoka, Katsuhiko; Shima, Yosuke; Oshima, Takeshi; Takata, Yasushi; Shimozaki, Kengo; Tsuchiya, Hiroyuki

    2018-02-01

    Female athletes are at greater risk of non-contact ACL injury. Three-dimensional kinematic analyses have shown that at-risk female athletes have a greater knee valgus angle during drop jumping. The purpose of this study was to evaluate the relationship between knee valgus angle and non-contact ACL injury in young female athletes using coronal-plane two-dimensional (2D) kinematic analyses of single-leg landing. Two hundred ninety-one female high school athletes newly enrolled in basketball and handball clubs were assessed. Dynamic knee valgus was analysed during single-leg drop jumps using 2D coronal images at hallux-ground contact and at maximal knee valgus. All subjects were followed up for 3 years for ACL injury. Twenty-eight (9.6%) of 291 athletes had ACL rupture, including 27 non-contact ACL injuries. The injured group of 27 knees with non-contact ACL injury was compared with a control group of 27 randomly selected uninjured knees. The relationship between initial 2D movement analysis results and subsequent ACL injury was investigated. Dynamic knee valgus was significantly greater in the injured group compared to the control group at hallux-ground contact (2.1 ± 2.4 vs. 0.4 ± 2.2 cm, P = 0.006) and at maximal knee valgus (8.3 ± 4.3 vs. 5.1 ± 4.1 cm, P = 0.007). The results of this study confirm that dynamic knee valgus is a potential risk factor for non-contact ACL injury in female high school athletes. Fully understanding the risk factors that increase dynamic knee valgus will help in designing more appropriate training and interventional strategies to prevent injuries in at-risk athletes. Prognostic studies, Level II.

  11. Checkrein deformity due to extensor hallucis longus hypotrophy treated with extensor digitorum longus tendon transfer.

    Science.gov (United States)

    Kurashige, Toshinori; Kawabata, Kensuke; Suzuki, Seiichi

    2014-06-01

    Checkrein deformity is a relatively rare condition caused by hypotrophy or adhesion of a tendon after a lower leg injury. The occurrence of this condition due to the dysfunction of the extensor hallucis longus (EHL) is extremely rare. Only a few related case reports have been published, and Z-lengthening of the EHL tendon was performed for almost all patients. We report a case of checkrein deformity due to EHL hypotrophy. The patient was involved in a traffic accident 7 years ago. He sustained left tibial and fibular closed diaphyseal fractures and underwent minimally invasive plate osteosynthesis. He continued to have left great toe symptoms characterized by dorsiflexion of the great toe during ankle plantarflexion. The EHL had become an insufficient power source because of considerable hypotrophy. Therefore, a tendon transfer using the extensor digitorum longus to the second toe was performed as a primary treatment. Copyright © 2014 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  12. A Progressive 5-Week Exercise Therapy Program Leads to Significant Improvement in Knee Function Early After Anterior Cruciate Ligament Injury

    Science.gov (United States)

    EITZEN, INGRID; MOKSNES, HÅVARD; SNYDER-MACKLER, LYNN; RISBERG, MAY ARNA

    2011-01-01

    STUDY DESIGN Prospective cohort study without a control group. OBJECTIVES Firstly, to present our 5-week progressive exercise therapy program in the early stage after anterior cruciate ligament (ACL) injury. Secondly, to evaluate changes in knee function after completion of the program for patients with ACL injury in general and also when classified as potential copers or noncopers, and, finally, to examine potential adverse events. BACKGROUND Few studies concerning early-stage ACL rehabilitation protocols exist. Consequently, little is known about the tolerance for, and outcomes from, short-term exercise therapy programs in the early stage after injury. METHODS One-hundred patients were included in a 5-week progressive exercise therapy program, within 3 months after injury. Knee function before and after completion of the program was evaluated from isokinetic quadriceps and hamstrings muscle strength tests, 4 single-leg hop tests, 2 different self-assessment questionnaires, and a global rating of knee function. A 2-way mixed-model analysis of variance was conducted to evaluate changes from pretest to posttest for the limb symmetry index for muscle strength and single-leg hop tests, and the change in scores for the patient-reported questionnaires. In addition, absolute values and the standardized response mean for muscle strength and single-leg hop tests were calculated at pretest and posttest for the injured and uninjured limb. Adverse events during the 5-week period were recorded. RESULTS The progressive 5-week exercise therapy program led to significant improvements (Ptherapy programs are well tolerated and should be incorporated in early-stage ACL rehabilitation, either to improve knee function before ACL reconstruction or as a first step in further nonoperative management. PMID:20710097

  13. Knee Injuries

    Science.gov (United States)

    ... up stairs or hills. Treatment may involve surgery. Bursitis A bursa is a sac filled with fluid ... friction, it can develop into a condition called bursitis . Symptoms of bursitis in the knee include warmth, ...

  14. Knee disarticulation

    Directory of Open Access Journals (Sweden)

    Antun Muljačić

    2009-08-01

    Full Text Available In this paper we presented three patients withknee disarticulation performed according toBaumgartner. The Baumgartner tehnique and theapplication of knee disarticulation prosthesis appearedto be superior in comparisson with othermethods.

  15. Unilateral Variation in Extensor digitorum longus muscle.

    Science.gov (United States)

    Banerje, A; Singh, S; Raza, K; Rani, N; Kaler, S

    2016-01-01

    During a routine dissection of an adult embalmed male cadaver for educational purpose in the department of anatomy at AIIMS, New Delhi, India, a rare unilateral variation of extensor digitorum longus (EDL) was found which is a muscle of anterior compartment of the leg. There was a split tendon of EDL muscle in the anterior compartment of left leg which became a common tendon in front of the ankle joint. This common tendon of EDL muscle again divided into four slips and were inserted in to the lateral four toes. In the upper part of the leg, the anterior tibial vessel and deep fibular nerve lie between the EDL and tibialis anterior. Knowledge of this type of anomaly is useful in diagnosis and treatment of compartmental syndrome. One of the tendon from the split tendon of EDL muscle can be used as a graft in tendon replacement surgeries. The split tendon may also be capable for some precise movements of the toes.

  16. Knee kinetic pattern during gait and anterior knee pain before and after rehabilitation in patients with patellofemoral pain syndrome.

    Science.gov (United States)

    Claudon, B; Poussel, M; Billon-Grumillier, C; Beyaert, C; Paysant, J

    2012-05-01

    Patellofemoral pain is likely due to compressive force acting on the patella related in turn to knee extension moment. The latter variable was assumed to be (i) reduced during short-distance free walking in case of patellofemoral pain syndrome and (ii) increased after therapeutic pain reduction. Peak knee extension moment at beginning of stance phase was recorded by three-dimensional gait analysis in 22 controls and in 23 patients with patellofemoral pain syndrome before and after rehabilitation of knee extensors and flexors to reduce the pain. Pain would occur mainly in stressful activities such as stair negotiation or squatting and was quantified by the anterior knee pain scale. Peak knee extension moment was significantly reduced in all the patients before treatment (n=23) compared to controls, although no one had pain during free walking. In the 17 patients who experienced significant post-rehabilitation pain reduction in their stressful activities, the peak knee extension moment was significantly reduced before treatment compared to controls and significantly increased after treatment, reaching values similar to control values. The peak knee extension moment during free walking appears to be a good kinetic variable related to a compensatory mechanism limiting or avoiding anterior knee pain and may be of interest in assessing knee dynamics alteration in patients with PFPS. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Lower-limb extensor power and lifting characteristics in disabled elders.

    Science.gov (United States)

    Dancewicz, Teresa M; Krebs, David E; McGibbon, Chris A

    2003-01-01

    Few reports address lifting in disabled elders. Resistance training may facilitate function by improving coordination and muscular recruitment in common lifting tasks. Subjects were considered "functionally limited" if they reported a limitation in at least 1 of 9 possible functional areas listed on the Short-Form Health Survey physical function scale (SF-36), excluding the vigorous activity item. Eighty-nine functionally limited elders (60.3 to 89.8 years old) consented to participate in an intervention trial consisting of a 6-month in-home video-facilitated resistance exercise program using elastic bands. Biomechanical variables (leg extensor power, work, squared jerk), temporal outcomes (lift time and time to peak leg powers), and leg extensor strength were analyzed with the use of analysis of variance (ANOVA) between the (1) experimental group versus control group and the (2) subgroup of the weakest third of subjects (pretest leg extensor strength as percent of body weight [BW]). The experimental group had significant improvements in strength in knee extension (16.7%) and hip extension (20.5%). Resistance-trained weak subjects significantly increased hip extension strength compared to controls. A trend toward improved performance in lifting--decreased total lift time--was noted in the resistance-trained subjects. Significant correlations were found between total leg extension power, total leg extension strength, total work, and lift time. Resistance-trained disabled elders demonstrated strength benefits and several trends consistent with improved coordination and more efficient lifting. Leg-muscle power was related to better functional performance in lifting.

  18. Is the relationship between increased knee muscle strength and improved physical function following exercise dependent on baseline physical function status?

    Science.gov (United States)

    Hall, Michelle; Hinman, Rana S; van der Esch, Martin; van der Leeden, Marike; Kasza, Jessica; Wrigley, Tim V; Metcalf, Ben R; Dobson, Fiona; Bennell, Kim L

    2017-12-08

    Clinical guidelines recommend knee muscle strengthening exercises to improve physical function. However, the amount of knee muscle strength increase needed for clinically relevant improvements in physical function is unclear. Understanding how much increase in knee muscle strength is associated with improved physical function could assist clinicians in providing appropriate strength gain targets for their patients in order to optimise outcomes from exercise. The aim of this study was to investigate whether an increase in knee muscle strength is associated with improved self-reported physical function following exercise; and whether the relationship differs according to physical function status at baseline. Data from 100 participants with medial knee osteoarthritis enrolled in a 12-week randomised controlled trial comparing neuromuscular exercise to quadriceps strengthening exercise were pooled. Participants were categorised as having mild, moderate or severe physical dysfunction at baseline using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Associations between 12-week changes in physical function (dependent variable) and peak isometric knee extensor and flexor strength (independent variables) were evaluated with and without accounting for baseline physical function status and covariates using linear regression models. In covariate-adjusted models without accounting for baseline physical function, every 1-unit (Nm/kg) increase in knee extensor strength was associated with physical function improvement of 17 WOMAC units (95% confidence interval (CI) -29 to -5). When accounting for baseline severity of physical function, every 1-unit increase in knee extensor strength was associated with physical function improvement of 24 WOMAC units (95% CI -42 to -7) in participants with severe physical dysfunction. There were no associations between change in strength and change in physical function in participants with mild or moderate physical

  19. Lipoma arborescens of the suprapatellar bursa and extensor digitorum longus tendon sheath: report of 2 cases.

    Science.gov (United States)

    Senocak, Efsun; Gurel, Kamil; Gurel, Safiye; Ozturan, Kutay Engin; Cakici, Husamettin; Yilmaz, Fahri; Boran, Cetin

    2007-10-01

    Lipoma arborescens (diffuse articular lipomatosis) is a rare intra-articular lesion consisting of subsynovial villous proliferation of mature fat cells. The usual clinical presentation is painless swelling. The aim of this series was to emphasize the importance of gray scale and color Doppler sonography through the investigation of chronic joint swelling. Lipoma arborescens of the knee and extensor digitorum longus tendon sheath at the ankle region are described. The latter is extremely rare. We examined 2 patients with sonography before using cross-sectional modalities. Gray scale sonography revealed hyperechoic irregular villous and frondlike projections within prominent joint effusion. A wavelike motion of the projections was shown by dynamic compression and manipulation of the effusion. We observed moderate vascularity on color Doppler sonography. Spectral analysis revealed a low-resistance arterial waveform. Gray scale sonography is a useful diagnostic modality that can be performed to evaluate chronic joint swelling before the use of cross-sectional and more expensive modalities.

  20. Snapping wrist due to multiple accessory tendon of first extensor compartment.

    Science.gov (United States)

    Subramaniyam, S Dhiyaneswaran; Purushothaman, Rajesh; Zacharia, Balaji

    2018-01-01

    Snapping phenomena result from the sudden impingement between anatomical and/or heterotopical structures with subsequent abrupt movement and noise. Snaps are variously perceived by patients, from mild discomfort to significant pain requiring surgical management. snapping syndrome occurs at various site like hip, knee, shoulder and wrist. There are many cadaveric studies shows accessory tendon in first extensor compartment of wrist. We present a 19 year old male presents catching sensation and occasional radial side wrist pain for 6 months. Finkelstein test was negative. Radiograph showed small bony projection over the radial styloid. MRI wrist was reported as normal but retrospective analysis of image shows multiple tendons. Intraopertively we found multiple accessory tendon of extensor pollicis brevis which is causing snapping. Fibrous tunnel release with tenotomy of few accessory tendons done. On table patients catching sensation was assessed and found to be relieved. Patient is not having snapping on his follow up visit and able to carry out his daily activity without difficulties. There are various causes for snapping wrist syndrome. Multiple accessory tendon can also cause snapping as shown in this case report. Moreover am presenting this case to highlight the diagnostic failure with non dynamic radiological investigation and to consider multiple accessory tendon as differential diagnosis for snapping wrist syndrome. Also suggest dynamic study could be a better choice of investigation to diagnosis snapping syndrome. First compartment tunnel release with few accessory tendon slip tenotomy gives good result. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Joint position sense and rehabilitation in the anterior cruciate ligament deficient knee.

    Science.gov (United States)

    Carter, N D; Jenkinson, T R; Wilson, D; Jones, D W; Torode, A S

    1997-09-01

    Impaired joint position sense (JPS) has been shown in anterior cruciate ligament (ACL) deficient and osteoarthritic knees. The relation between JPS and function is uncertain. The aim of this study was to determine further if ACL deficient knees show abnormal JPS and the effect of exercise therapy on JPS, and also to assess the relation between JPS, functional stability, and strength. Fifty patients (46 men and four women, mean age 26.3 years) with unilateral ACL deficient knees were assessed on admission and after rehabilitation (5 hours a day for four weeks). JPS was assessed by reproduction of passive positioning using a visual analogue incorporating a goniometer. Knee stability was analysed by self report questionnaire (score 0-280) and functional activity test (single leg hop and figure of eight run). Isokinetic dynamometry was performed to evaluate quadriceps and hamstring peak torque strength. Controls were either age and sex matched individuals or the contralateral knee. Statistical analysis was by Wilcoxon signed rank test and Spearman rank order correlation coefficient. JPS was impaired in ACL deficient knees. The mean (SD) errors in reproducing angles were 9.4 (3.1) degrees and 7.1 (2.3) degrees for the ACL deficient knee and control knee respectively (P testing (hop: on admission 148.7 (37.3) cm, after rehabilitation 169.8 (31.1) cm, P tests (hop and figure of eight run), the responses to the questionnaire, or strength. There was no correlation between the responses to the questionnaire and functional activity tests or muscle strength. JPS was impaired in ACL deficient knees. Although knee stability improved with exercise therapy, there was no improvement in JPS. The role of JPS in the stability of ACL deficient knees remains unclear.

  2. Intra-Articular Analgesia and Steroid Reduce Pain Sensitivity in Knee OA Patients

    DEFF Research Database (Denmark)

    Jørgensen, Tanja Schjødt; Graven-Nielsen, Thomas; Ellegaard, Karen

    2014-01-01

    before, immediately after, and two weeks after ultrasound guided intra-articular injection of lidocaine combined with glucocorticosteroid. Computer-controlled and manual pressure algometers were used to assess PPT on the knee, vastus lateralis, tibialis anterior, and the extensor carpi radialis longus...

  3. Fast unilateral isometric knee extension torque development and bilateral jump height.

    NARCIS (Netherlands)

    C.J. de Ruiter; M.F. Bobbert; Dr. D.M. van Leeuwen; A.J. Heijblom; A. de Haan

    2006-01-01

    PURPOSE: We hypothesized that the initial rate (first 40 ms) of unilateral knee extensor torque development during a maximally fast isometric contraction would depend on the subjects' ability for fast neural activation and that it would predict bilateral jumping performance. METHODS: Nine males

  4. Fast unilateral isometric knee extension torque development and bilateral jump height.

    NARCIS (Netherlands)

    de Ruiter, C.J.; Leeuwen, D.; Heijblom, A.; Bobbert, M.F.; de Haan, A.

    2006-01-01

    Purpose: We hypothesized that the initial rate (first 40 ms) of unilateral knee extensor torque development during a maximally fast isometric contraction would depend on the subjects' ability for fast neural activation and that it would predict bilateral jumping performance. Methods: Nine males

  5. Quadriceps weakness in a family with nemaline myopathy; influence of knee angle

    NARCIS (Netherlands)

    Gerrits, K.H.L.; Gommans, I.M.P.; van Engelen, B.G.M.; de Haan, A.

    2003-01-01

    Nemaline myopathy is a congenital neuromuscular disorder, which primarily affects the thin filaments. Clinically the most important feature is muscle weakness; however, this weakness is poorly understood. The present investigation aimed to determine the torque angle relationship of the knee extensor

  6. A rare anomaly of the extensor digitorum longus.

    Science.gov (United States)

    Sakuma, Eisuke; Kato, Hiroyuki; Honda, Nobuhiko; Mabuchi, Yoshio; Soji, Tsuyoshi

    2004-12-01

    We encountered the absence of the tendon to the fourth toe of the extensor digitorum longus muscle of the right leg in the body of a 73-year-old Japanese woman during the course of educational dissection at Nagoya City University Medical School. The tendon to the fourth toe of the extensor digitorum longus muscle was solely absent. To our knowledge, this anatomical variation has never been cited in the medical literature. We document the precise gross anatomical findings with some morphometric measurements. Moreover, we discuss the morphology of this anomaly in relation to previously described variations and anomalies of the extensor digitorum longus muscle.

  7. Transfer of either index finger extensor tendon to the extensor pollicis longus tendon

    Science.gov (United States)

    Meads, Bryce M; Bogoch, Earl R

    2004-01-01

    BACKGROUND: Extensor pollicis longus (EPL) tendon ruptures have been treated succesfully with the transfer of the extensor indicis proprius (EIP) tendon. Situations exist in which, due to intraoperative observations, another tendon transfer may be considered preferable to the standard EIP transfer method. OBJECTIVES: To determine whether transfer of the extensor digitorum communis II (EDC II) tendon from the index finger to the EPL tendon, leaving the EIP tendon to the index finger intact, would serve as an equally efficient transfer and not adversely affect the function of the hand. METHODS: Two patients who had the EDC II tendon transferred to the ruptured EPL tendon, and two patients who had the EIP tendon transferred, were retrospectively reviewed. In each transfer type, one patient had suffered an EPL tendon rupture after a Colles’ fracture, and the other had rheumatoid arthritis. The rupture occurred on the non-dominant side in one patient in each transfer type. Each patient was examined and subjected to range of motion and power testing at least one year following surgery. RESULTS: All four patients showed a minimal extension lag with the lift off test, but there was no noticeable difference in range of motion, pinch grip and hand grip strength between the transfer types. Both EDC II transfer patients demonstrated an 8° to 15° loss of thumb interphalangeal joint flexion compared with the unoperated side; EIP transfer patients demonstrated less than a 5° loss. Three patients demonstrated a minor extension lag in the index finger and middle finger. Extension power of the thumb and index finger in all patients varied with wrist flexion and extension and ranged from 50% to 150% of the unoperated side. CONCLUSIONS: These case reports suggest that either index finger tendon may be successfully transferred in EPL tendon ruptures. PMID:24115870

  8. Drill Penetration Injury to Extensor Tendons: A Biomechanical Analysis.

    Science.gov (United States)

    Mahylis, Jared M; Burwell, Anora K; Bonneau, Laura; Marshall, Lynn M; Mirarchi, Adam J

    2017-05-01

    Little is known about extensor tendon failure following drill injury at the time of volar plate fixation. Our goals were to analyze extensor tendon injury following simulated drill penetration, and change in tendon displacement during cyclic loading following simulated drill penetration injury. Extensor pollicis longus (EPL) and extensor carpi radialis brevis (ECRB) tendons were harvested from 9 fresh frozen cadaveric arms. Eighteen EPL and 18 ECRB samples were created from harvested tendons. Drill penetration injury was performed in either a continuous or an oscillating mode. Injured tendons were subjected to 1200 cycles at 1- to 15-kg cyclic load at a frequency of 1 Hz, and analyzed for failure at drill sites and change in displacement throughout the testing cycle. Ten EPL samples and 16 ECRB samples completed testing without failure. Tendon type (ECRB, EPL), mode of injury (continuous, oscillating), and location (proximal, distal) did not affect tendon displacement during loading. A single EPL tendon failed following continuous drill penetration injury. Extensor carpi radialis brevis samples had a mean change in displacement of 2.8 (standard deviation [SD]: 1.5 mm) and 5.9 mm (SD: 4.7 mm) for oscillating and continuous modes, respectively. Six EPL samples had a mean change in displacement of 4.7 (SD: 2.7 mm) and 4.3 mm (SD: 1.8 mm) for oscillating and continuous modes, respectively. Complete extensor tendon failure due to drill penetration was rare. Drill mode did not affect the degree of elongation. Increasing cyclic loading of extensor tendons after drill injury caused modest extensor tendon elongation.

  9. Hydrotherapy improves pain and function in older women with knee osteoarthritis: a randomized controlled trial.

    Science.gov (United States)

    Dias, João Marcos; Cisneros, Lígia; Dias, Rosângela; Fritsch, Carolina; Gomes, Wellington; Pereira, Leani; Santos, Mary Luci; Ferreira, Paulo Henrique

    Currently, there is poor evidence of the effect of hydrotherapy alone on patients with hip or knee osteoarthritis. The study aimed to assess the impact of hydrotherapy on pain, function, and muscle function in older women with knee osteoarthritis. A randomized controlled trial was conducted to evaluate the efficacy of hydrotherapy in women with knee osteoarthritis. Seventy-three women aged 65 and older were randomized to hydrotherapy (n=36) or a control group (n=37). The hydrotherapy group received the intervention program in a heated pool (twice per week for six weeks) and an educational protocol while the control group received an educational protocol only. Primary outcomes (before and post-treatment) were pain intensity (0-100) and function (0-100), assessed with the WOMAC questionnaire. Secondary outcomes (before and post-treatment) were knee extensor and knee flexor muscle performance (strength, power, and endurance), assessed by an isokinetic dynamometer. The magnitude of change between the groups for the outcomes was calculated using linear regression models adjusted by baseline outcome values. The hydrotherapy group had better outcomes for pain (adjusted mean difference=11 points, 95% CI: 3-18) and function (adjusted mean difference=12 points, 95% CI: 5-18). Patients receiving hydrotherapy had better performance for knee flexor and extensor strength, knee flexor power, and knee extensor endurance. Older women with knee osteoarthritis are likely to have benefits from a course of hydrotherapy exercises. Registry of clinical trials (Trial number RBR-8F57KR) - http://www.ensaiosclinicos.gov.br/rg/RBR-8f57kr/. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

  10. Swollen Knee (Water on the Knee)

    Science.gov (United States)

    ... to experience the types of knee injuries that cause swelling. Obesity. Excess weight puts added stress on the knee ... degeneration that can lead to a swollen knee. Obesity increases your risk of osteoarthritis, one of the more frequent causes of knee swelling. Complications Complications of a swollen ...

  11. Impact of treatment strategy and physical performance on future knee-related self-efficacy in individuals with ACL injury

    DEFF Research Database (Denmark)

    Flosadottir, Vala; Frobell, Richard; Roos, Ewa M

    2018-01-01

    BACKGROUND: In people with anterior cruciate ligament (ACL) injury, high self-efficacy facilitates recovery, indicated by improved muscle function, reduced knee symptoms and increased physical activity. Impact of treatment on future self-efficacy is however not well investigated. The aims...... of the study were to 1) investigate knee-related self-efficacy 6 years after acute ACL injury in patients treated with exercise therapy alone or in combination with either early or the option of delayed ACL reconstruction (ACLR), and 2) to investigate associations between single-leg physical performance...... at various time points after ACL injury and knee self-efficacy at 6 years after injury. METHODS: Participants (n = 121) originated from the KANON-study (ISRCTN84752559), a treatment RCT including active adults with acute ACL injury treated with structured exercise therapy combined with early or the option...

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

    Science.gov (United States)

    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 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.

  13. Runner's Knee

    Science.gov (United States)

    ... If you're used to only running a mile or so, don't try to go out and suddenly run 5 miles. Work up to it with a series of ... supporting structures. Surgery is only used as a last resort, though. Most cases of runner's knee get ...

  14. Intermuscular interaction via myofascial force transmission: Effects of tibialis anterior and extensor digitorum longus length on force transmission from rat extensor digitorum longus muscle

    NARCIS (Netherlands)

    Maas, Huub; Baan, Guus C.; Huijing, P.A.J.B.M.

    2001-01-01

    Force transmission in rat anterior crural compartment, containing tibialis anterior (TA), extensor hallucis longus (EHL) and extensor digitorum longus (EDL) muscles, was investigated. These muscles together with the muscles of the peroneal compartment were excited maximally. Force was measured at

  15. Intermuscular interaction via myofascial force transmission: Effects of tibialis anterior and extensor digitrum longus length on force transmission from rat extensor digitorum longus muscle

    NARCIS (Netherlands)

    Maas, H.; Baan, G.C.; Huijing, P.A.J.B.M.

    2001-01-01

    Force transmission in rat anterior crural compartment, containing tibialis anterior (TA), extensor hallucis longus (EHL) and extensor digitorum longus (EDL) muscles, was investigated. These muscles together with the muscles of the peroneal compartment were excited maximally. Force was measured at

  16. Altered knee joint neuromuscular control during landing from a jump in 10-15 year old children with generalised joint hypermobility. A substudy of the CHAMPS-study Denmark

    DEFF Research Database (Denmark)

    Junge, Tina; Juul-Kristensen, B; Bloch Thorlund, Jonas

    Generalised Joint Hypermobility (GJH) is considered an intrinsic risk factor for knee injuries. Knee neuromuscular control during landing may be altered in GJH due to reduced passive stability. The aim was to identify differences in knee neuromuscular control during landing of the Single......-Leg-Hop-for-Distance test (SLHD) in 25 children with GJH compared to 29 children without GJH (controls), all 10-15 years. Inclusion criteria for GJH: Beighton score ≥5/9 and minimum one hypermobile knee. EMG was recorded from the quadriceps, the hamstring and the calf muscles, presented relative to Maximum Voluntary...... Electrical activity (MVE). There was no difference in jump length between groups. Before landing, GJH had 33% lower Semitendinosus, but 32% higher Gastrocnemius Medialis activity and 39% higher co-contraction of the lateral knee muscles, than controls. After landing, GJH had 36% lower Semitendinosus activity...

  17. Altered knee joint neuromuscular control during landing from a jump in 10-15year old children with Generalised Joint Hypermobility. A substudy of the CHAMPS-study Denmark

    DEFF Research Database (Denmark)

    Junge, Tina; Wedderkopp, Niels; Thorlund, Jonas Bloch

    2015-01-01

    Generalised Joint Hypermobility (GJH) is considered an intrinsic risk factor for knee injuries. Knee neuromuscular control during landing may be altered in GJH due to reduced passive stability. The aim was to identify differences in knee neuromuscular control during landing of the Single......-Leg-Hop-for-Distance test (SLHD) in 25 children with GJH compared to 29 children without GJH (controls), all 10-15years. Inclusion criteria for GJH: Beighton score⩾5/9 and minimum one hypermobile knee. EMG was recorded from the quadriceps, the hamstring and the calf muscles, presented relative to Maximum Voluntary...... Electrical activity (MVE). There was no difference in jump length between groups. Before landing, GJH had 33% lower Semitendinosus, but 32% higher Gastrocnemius Medialis activity and 39% higher co contraction of the lateral knee muscles, than controls. After landing, GJH had 36% lower Semitendinosus activity...

  18. Customizing Extensor Reconstruction in Vascularized Toe Joint Transfers to Finger Proximal Interphalangeal Joints: A Strategic Approach for Correcting Extensor Lag.

    Science.gov (United States)

    Loh, Charles Yuen Yung; Hsu, Chung-Chen; Lin, Cheng-Hung; Chen, Shih-Heng; Lien, Shwu-Huei; Lin, Chih-Hung; Wei, Fu-Chan; Lin, Yu-Te

    2017-04-01

    Vascularized toe proximal interphalangeal joint transfer allows the restoration of damaged joints. However, extensor lag and poor arc of motion have been reported. The authors present their outcomes of treatment according to a novel reconstructive algorithm that addresses extensor lag and allows for consistent results postoperatively. Vascularized toe joint transfers were performed in a consecutive series of 26 digits in 25 patients. The average age was 30.5 years, with 14 right and 12 left hands. Reconstructed digits included eight index, 10 middle, and eight ring fingers. Simultaneous extensor reconstructions were performed and eight were centralization of lateral bands, five were direct extensor digitorum longus-to-extensor digitorum communis repairs, and 13 were central slip reconstructions. The average length of follow-up was 16.7 months. The average extension lag was 17.9 degrees. The arc of motion was 57.7 degrees (81.7 percent functional use of pretransfer toe proximal interphalangeal joint arc of motion). There was no significant difference in the reconstructed proximal interphalangeal joint arc of motion for the handedness (p = 0.23), recipient digits (p = 0.37), or surgical experience in vascularized toe joint transfer (p = 0.25). The outcomes of different techniques of extensor mechanism reconstruction were similar in terms of extensor lag, arc of motion, and reconstructed finger arc of motion compared with the pretransfer toe proximal interphalangeal joint arc of motion. With this treatment algorithm, consistent outcomes can be produced with minimal extensor lag and maximum use of potential toe proximal interphalangeal joint arc of motion. Therapeutic, IV.

  19. Mechanical contributors to sex differences in idiopathic knee osteoarthritis

    Directory of Open Access Journals (Sweden)

    Nicolella Daniel P

    2012-12-01

    Full Text Available Abstract The occurrence of knee osteoarthritis (OA increases with age and is more common in women compared with men, especially after the age of 50 years. Recent work suggests that contact stress in the knee cartilage is a significant predictor of the risk for developing knee OA. Significant gaps in knowledge remain, however, as to how changes in musculoskeletal traits disturb the normal mechanical environment of the knee and contribute to sex differences in the initiation and progression of idiopathic knee OA. To illustrate this knowledge deficit, we summarize what is known about the influence of limb alignment, muscle function, and obesity on sex differences in knee OA. Observational data suggest that limb alignment can predict the development of radiographic signs of knee OA, potentially due to increased stresses and strains within the joint. However, these data do not indicate how limb alignment could contribute to sex differences in either the development or worsening of knee OA. Similarly, the strength of the knee extensor muscles is compromised in women who develop radiographic and symptomatic signs of knee OA, but the extent to which the decline in muscle function precedes the development of the disease is uncertain. Even less is known about how changes in muscle function might contribute to the worsening of knee OA. Conversely, obesity is a stronger predictor of developing knee OA symptoms in women than in men. The influence of obesity on developing knee OA symptoms is not associated with deviation in limb alignment, but BMI predicts the worsening of the symptoms only in individuals with neutral and valgus (knock-kneed knees. It is more likely, however, that obesity modulates OA through a combination of systemic effects, particularly an increase in inflammatory cytokines, and mechanical factors within the joint. The absence of strong associations of these surrogate measures of the mechanical environment in the knee joint with sex

  20. [Benefit of isokinetic evaluations of knee before and after anterior cruciate ligament reconstruction in soccer players].

    Science.gov (United States)

    Olivier, N; Rogez, J; Masquelier, B

    2007-10-01

    The aim of this study was to analyse the evolution of the isokinetic performance of the knee flexor and extensor muscles in soccer players before and after intra-articular anterior cruciate ligament reconstruction (Kennet-Jones). Two isokinetic evaluations were carried out before surgery and after rehabilitation (i.e. 4 months later) in 18 soccer players. The initial evaluation showed that the stabilizing muscles of the knee were affected differently after lesion of the external anterior crossed ligament. At the opposite of the flexor muscles, the performance of the knee extensor muscles of the injured leg was significantly reduced as compared with that of the healthy leg (peak torque at 90 degrees /s, -16%; power at 180 degrees /s, -14%; total work at 240 degrees /s, -11%). Even if 4 months after surgery, this deficit was accentuated (peak torque at 90 degrees /s, -26%; power at 180 degrees /s, -23%; total work at 240 degrees /s, -19%), the preoperative results of the knee extensor muscle do not condition the postoperative performance. After a rupture of the external anterior crossed ligament, a regular program of isokinetic evaluation of the knee seems to be relevant in the follow-up of the wounded athlete. The evaluation before surgery can be used as reference, and from a psychological point of view, this evaluation can create confidence in the athlete during hospitalization. A second evaluation 4 months after surgery can be used to quantify the muscular deficit to direct the exercises of rehabilitation.

  1. Assessment of isokinetic knee strength in elite young female basketball players: correlation with vertical jump.

    Science.gov (United States)

    Rouis, M; Coudrat, L; Jaafar, H; Filliard, J-R; Vandewalle, H; Barthelemy, Y; Driss, T

    2015-12-01

    To explore the isokinetic concentric strength of the knee muscle groups, and the relationship between the isokinetic knee extensors strength and the vertical jump performance in young elite female basketball players. Eighteen elite female basketball players performed a countermovement jump, and an isokinetic knee test using a Biodex dynamometer. The maximal isokinetic peak torque of the knee extensor and flexor muscles was recorded at four angular velocities (90°/s, 180°/s, 240°/s and 300°/s) for the dominant and non-dominant legs. The conventional hamstring/quadriceps ratio (H/Q) was assessed at each angular velocity for both legs. There was no significant difference between dominant and non-dominant leg whatever the angular velocity (all P>0.05). However, the H/Q ratio enhanced as the velocity increased from 180°/s to 300°/s (Pvertical jump height. The highest one was found for the knee extensors peak torque at a velocity of 240°/s (r=0.88, Pvertical jump height. Interestingly, the H/Q ratio of the young elite female basketball players in the present study was unusual as it was close to that generally observed in regular sportsmen.

  2. ACL Injury Prevention Training Results in Modification of Hip and Knee Mechanics During a Drop-Landing Task.

    Science.gov (United States)

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

    2017-09-01

    Injury prevention training has been shown to be effective in reducing the incidence of noncontact anterior cruciate ligament (ACL) injury; however, the underlying reason for the success of these training programs is unclear. To investigate whether an ACL injury prevention program that has been shown to reduce the incidence of ACL injury alters sagittal plane hip and knee biomechanics during a drop-landing task. Descriptive laboratory study. Thirty female club soccer players (age range, 11-17 years) with no history of knee injury participated in this study. Kinematics and ground-reaction forces were collected while each participant performed a drop-landing task prior to and immediately after participation in a 12-week ACL injury prevention training program. After ACL injury prevention training, participants demonstrated decreased knee extensor moments ( P = .03), increased energy absorption at the hip ( P = .04), decreased knee-to-hip extensor moment ratios ( P = .05), and decreased knee-to-hip energy absorption ratios ( P = .03). Participation in an ACL injury prevention training program decreased reliance on the knee extensor muscles and improved use of the hip extensor muscles, which may explain the protective effect of this type of training program on ACL injury. Based on these findings, clinicians can better understand how ACL injury prevention training, such as the Prevent Injury and Enhance Performance (PEP) Program, may change movement behavior at both the hip and knee. Furthermore, the study findings may support the implementation of the PEP Program, or a similar program, for clinicians aiming to improve use of the hip in an effort to reduce knee loading and consequent injuries.

  3. Effects of step length, age, and fall history on hip and knee kinetics and knee co-contraction during the maximum step length test.

    Science.gov (United States)

    Schulz, Brian W; Jongprasithporn, Manutchanok; Hart-Hughes, Stephanie J; Bulat, Tatjana

    2013-10-01

    Maximum step length is a brief clinical test involving stepping out and back as far as possible with the arms folded across the chest. This test has been shown to predict fall risk, but the biomechanics of this test are not fully understood. Knee and hip kinetics (moments and powers) are greater for longer steps and for younger subjects, but younger subjects also step farther. To separate the effects of step length, age, and fall history on joint kinetics; healthy younger (age=27(5), N=14), older non-fallers (age=72(5), N=14), and older fallers (age=75(6), N=11) all stepped to the same relative target distances of 20-80% of their height. Knee and hip kinetics and knee co-contraction were calculated. Hip and knee kinetics and knee co-contraction all increased with step length, but older non-fallers and fallers utilized greater stepping hip and less stepping knee extensor kinetics. Fallers had greater stepping knee co-contraction than non-fallers. Stance knee co-contraction of non-fallers was similar to young for shorter steps and similar to fallers for longer steps. Age had minimal effects and fall history had no effects on joint kinetics of steps to similar distances. Effects of age and fall history on knee co-contraction may contribute to age-related kinetic differences and shorter maximal step lengths of older non-fallers and fallers, but step length correlated with every variable tested. Thus, declines in maximum step length could indicate declines in hip and knee extensor kinetics and impaired performance on similar tasks like recovering from a trip. © 2013.

  4. Does anterior knee pain severity and function relate to the frontal plane projection angle and trunk and hip strength in women with patellofemoral pain?

    Science.gov (United States)

    Almeida, Gabriel Peixoto Leão; Carvalho E Silva, Ana Paula de Moura Campos; França, Fábio Jorge Renovato; Magalhães, Maurício Oliveira; Burke, Thomaz Nogueira; Marques, Amélia Pasqual

    2015-07-01

    The aim of the present study was to determine the relationship between knee pain severity and function with the frontal plane projection angle (FPPA) and trunk and hip peak torque (PT) in women with patellofemoral pain (PFPS). Twenty-two women with PFPS were assessed. Knee pain severity (KPS) was assessed with an 11-point visual analog scale and function with an Anterior Knee Pain Scale. The FPPA was recorded with a digital camera. PT of extensors, abductors, and the lateral rotators of hip and lateral core stability were measured with a handheld dynamometer. FPPA was the only predictor for the KPS. Regarding predictors of function, PT of lateral core stability and the extensor and abductor of the hip explained 41.4% of the function. Increase in FPPA was associated with greater KPS, and the lowest PT of lateral core stability, hip abductors, and extensors was associated with lower function in women with PFPS. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Knee pain (image)

    Science.gov (United States)

    ... front of the knee can be due to bursitis, arthritis, or softening of the patella cartilage as ... knee. Overall knee pain can be due to bursitis, arthritis, tears in the ligaments, osteoarthritis of the ...

  6. Preventing Knee Injuries

    Science.gov (United States)

    ... Blog Skip breadcrumb navigation Preventing Knee Injuries Knee injuries in children and adolescent athletes may be the result of ... occur in childhood sports, but with any knee injury in a growing child there is a possibility of a fracture related ...

  7. Knee joint replacement - discharge

    Science.gov (United States)

    ... Knee replacement - total - discharge; Tricompartmental knee replacement - discharge; Osteoarthritis - knee replacement discharge ... such as downhill skiing or contact sports like football and soccer. But, you should be able to ...

  8. Extensor deficiency: first cause of childhood flexible flat foot.

    Science.gov (United States)

    Vittore, Donato; Patella, Vittorio; Petrera, Massimo; Caizzi, Gianni; Ranieri, Maurizio; Putignano, Piero; Spinarelli, Antonio

    2009-01-01

    Childhood flexible flat foot is the most common paramorphism of the lower limb. The cause is not a bony malformation of the foot but a functional deficiency of the anatomic structures supporting the plantar arch. These structures, working as active tie rods (the tibialis anterior and posterior muscles) or passive factors of support (flexor hallucis longus and flexor digitorum longus muscles) act together to maintain the plantar arch. Their deficiency is responsible for childhood flexible flat foot, characterized by a flattening of the plantar arch and calcaneus pronation (heel valgus) and manifested in the characteristic "duck walking" in children. Hypothesizing poor extensor activity of the tibialis anterior, extensor digitorum longus, and extensor hallucis longus muscles during the heel contact phase of the gait cycle, we began a preliminary study to evaluate, through superficial electromyography (sEMG), the activation of muscle groups involved in the pathogenesis of childhood flexible flat foot, in particular the tibialis anterior and extensor hallucis longus muscles, to plan a rehabilitative program addressing the strengthening of insufficient muscles. The therapeutic program should also include the use of a medial elastic push orthosis. Data obtained by sEMG highlight a reduced activation of muscles related to the grade of flat foot, emphasizing the concept that a reduced activation of extensor muscles may be involved in determining flexible flat foot.

  9. Impairment-targeted exercises for older adults with knee pain: a proof-of-principle study (TargET-Knee-Pain).

    Science.gov (United States)

    Wood, Laurence R J; Blagojevic-Bucknall, Milica; Stynes, Siobhán; D'Cruz, Deborah; Mullis, Ricky; Whittle, Rebecca; Peat, George; Foster, Nadine E

    2016-01-29

    Therapeutic exercise is an effective intervention for knee pain and osteoarthritis (OA) and should be individualised. In a preliminary, proof-of-principle study we sought to develop a home exercise programme targeted at specific physical impairments of weak quadriceps, reduced knee flexion range of motion (ROM) and poor balance, and evaluate whether receipt of this was associated with improvements in those impairments and in patient-reported outcomes among older adults with knee pain. This community-based study used a single group, before-after study design with 12-week follow-up. Participants were 58 adults aged over 56 years with knee pain and evidence of quadriceps weakness, loss of flexion ROM, or poor balance, recruited from an existing population-based, observational cohort. Participants received a 12-week home exercise programme, tailored to their physical impairments. The programme was led, monitored and progressed by a physiotherapist over six home visits, alternating with six telephone calls. Primary outcome measures were maximal isometric quadriceps strength, knee flexion ROM and timed single-leg standing balance, measured at baseline, 6 and 12 weeks by a research nurse blinded to the nature and content of participants' exercise programmes. Secondary outcome measures included the WOMAC. At 12 weeks, participants receiving strengthening exercises demonstrated a statistically significant change in quadriceps isometric strength compared to participants not receiving strengthening exercises: 3.9 KgF (95 % CI 0.1, 7.8). Changes in knee flexion ROM (2.1° (-2.3, 6.5)) and single-leg balance time (-2.4 s (-4.5, 6.7)) after stretching and balance retraining exercises respectively, were not found to be statistically significant. There were significant improvements in mean WOMAC Pain and Physical Function scores: -2.2 (-3.1, -1.2) and -5.1 (-7.8, -2.5). A 12-week impairment-targeted, home-based exercise programme for symptomatic knee OA appeared to be associated

  10. Knee mechanics during landing in anterior cruciate ligament patients: A longitudinal study from pre- to 12 months post-reconstruction.

    Science.gov (United States)

    Oberländer, Kai Daniel; Brüggemann, Gert-Peter; Höher, Jürgen; Karamanidis, Kiros

    2014-05-01

    Patients with a history of anterior cruciate ligament rupture are at elevated risk of developing knee osteoarthritis. Altered knee kinematics and kinetics during functional activities have been viewed as risk factors for cartilage breakdown and, therefore, one of the primary goals of anterior cruciate ligament reconstruction is to restore knee joint function. Patients' (n=18) knee mechanics while performing a single leg hop for distance were calculated for both legs using a soft-tissue artifact optimized rigid lower-body model at the pre-reconstruction state and six and twelve months after anterior cruciate ligament reconstruction. Independent of the analyzed time point the involved leg showed a lower external flexion and adduction moment at the knee, and an increased anterior translation and external rotational offset of the shank with respect to the thigh compared to the uninvolved leg. There were no differences for any of the analyzed knee kinematic and kinetic parameters within the control subject group. The identified kinematic changes can cause a shift in the normal load-bearing regions of the knee and may support the view that the risk of developing knee osteoarthritis in an anterior cruciate ligament ruptured joint while performing activities involving frequent landing and stopping actions is less likely to be associated with the knee adduction moment and is rather due to kinematic changes. Anterior cruciate ligament reconstruction surgery failed to restore normal knee kinematics during landing, potentially explaining the persistent risk for the development of knee osteoarthritis in patients who have returned to sports following reconstruction surgery. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Effect of shoes containing nanosilica particles on knee valgus in active females during landing

    Directory of Open Access Journals (Sweden)

    Zahra Bassiri

    2015-01-01

    Full Text Available Objective(s: The effect of silica nanoparticles (SNPs in sport shoes outsoles on the  parameters related to anterior cruciate ligament (ACL Injury has not been investigated. The aim of this study was to investigate the effect of shoes outsole containing a composite of thermoplastic elastomer based on styrene-butadiene and silica nanoparticles (TPEN shoe on Knee Valgus Angle (KVA as a risk factor of ACL injuries during landing Materials and Methods: Fourteen active healthy women without knee injuries and disorders performed bilateral drop jump (DJ and single leg drop landing (SLL tasks in barefoot, wearing shoes fabricated with polyvinyl chloride outsole (PVC shoe and TPEN shoes conditions , randomly. The knee valgus angle values of right and left legs were calculated in the landing conditions. Two factors repeated measures ANOVA were used to investigate the effect of landing and footwear conditions on KVA of right and left legs.  Results: For both left and right limbs, the KVA was at maximum and minimum values during landing with barefoot and TPEN shoes, respectively. PVC shoe significantly reduced the knee valgus by 3.84% in left and 4.18% in right knee (P

  12. Muscle strength, physical performance and physical activity as predictors of future knee replacement

    DEFF Research Database (Denmark)

    Skou, Søren T; Wise, Barton L; Lewis, Cora E

    2016-01-01

    of the past 30 days at baseline were included (n=1,257; mean (SD) age of 62.2 (8.2)). We examined the association between 1) baseline peak isokinetic knee extensor strength, (60°/sec, maximum out of 4 trials), 2) best time to stand in timed chair stand (2 trials of 5 repetitions), and 3) baseline Physical......OBJECTIVE: To investigate associations between lower levels of muscle strength, physical performance and physical activity and the risk of knee replacement (KR) in older adults with frequent knee pain. METHOD: Participants from the Multicenter Osteoarthritis Study (MOST) with knee pain on most...... a decreased risk of KR in women (p injury, previous knee surgery, and WOMAC pain (HR (95...

  13. Effects of the abdominal drawing-in maneuver on muscle activity, pelvic motions, and knee flexion during active prone knee flexion in patients with lumbar extension rotation syndrome.

    Science.gov (United States)

    Park, Kyue-Nam; Cynn, Heon-Seock; Kwon, Oh-Yun; Lee, Won-Hwee; Ha, Sung-Min; Kim, Su-Jung; Weon, Jong-Hyuck

    2011-09-01

    To investigate the effects of performing an abdominal drawing-in maneuver (ADIM) during active prone knee flexion on the hamstrings and erector spinae muscle activity, the amounts of pelvic motion and knee flexion, and onset of pelvic movements. Comparative, repeated-measures study. University research laboratory. Men patients (N=18) with lumbar extension rotation syndrome. Subjects performed prone knee flexion in 2 conditions. To measure muscle activity, surface electromyogram (EMG) of both erector spinae and the medial and lateral hamstrings was performed. Kinematic data on the pelvic motion and knee flexion were measured using a 3-dimensional motion analysis system. Repeated 1-way analysis of variance was used for the statistical analysis. Significantly decreased electromyographic activity in the right and left erector spinae and significantly increased electromyographic activity in the medial and lateral hamstrings activity were shown during prone knee flexion in ADIM condition using the pressure biofeedback unit. In addition, the amounts of anterior pelvic tilt, pelvic rotation, knee flexion, and perceived pain decreased significantly during prone knee flexion in the ADIM condition compared with the same maneuver in the non-ADIM condition. The onset of anterior pelvic tilt and pelvic rotation occurred significantly earlier in the non-ADIM condition, compared with the ADIM condition. ADIM effectively increased activation of knee flexors, decreased activation of back extensors, and reduced the pelvic motions and low back pain during prone knee flexion in patients with lumbar extension rotation syndrome. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  14. Closed traumatic rupture of the extensor hallucis longus muscle.

    Science.gov (United States)

    Tadros, Ayman M A; Al-Shaeel, Rashed A

    2013-01-01

    A 23-year-old healthy laborer involved in a work-related injury, sustained excessive left ankle plantarflexion, which resulted in closed rupture of the extensor hallucis longus muscle without any predisposing factors. He had an associated fracture of the second metatarsal shaft. The muscle proximal to the musculotendinous junction was excised, and the tendon was looped through a longitudinal slit in the main extensor digitorum communis tendon and sutured to it. The second metatarsal fracture was fixed with Kirschner wires. The patient regained full function and was symptom free 6 months after surgery. Copyright © 2013 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  15. The knee

    International Nuclear Information System (INIS)

    Rand, J.A.; Berquist, T.H.

    1985-01-01

    Evaluation of infection is difficult on the basis of radiographs. A clinical history suggestive of infection, such as excessive prolonged pain, drainage, fever, or a postoperative hematoma, is helpful in assessment. Radiographs may reveal periosteal new bone formation in long-standing cases of infection. Aspiration of the knee may or may not be helpful. Differential Tc-99m and gallium bone scans may be a useful adjunct in difficult cases. The gallium scan should show increased uptake relative to the Tc-99m scan to be considered positive. Bone scanning is not a useful criterion by itself for assessment of loosening

  16. Trunk extensor muscle fatigue influences trunk muscle activities.

    Science.gov (United States)

    Hoseinpoor, Tahere Seyed; Kahrizi, Sedighe; Mobini, Bahram

    2015-01-01

    Trunk muscles fatigue is one of the risk factors in workplaces and daily activities. Loads would be redistributed among active and passive tissues in a non-optimal manner in fatigue conditions. Therefore, a single tissue might be overloaded with minimal loads and as a result the risk of injury would increase. The goal of this paper was to assess the electromyographic response of trunk extensor and abdominal muscles after trunk extensor muscles fatigue induced by cyclic lifting task. This was an experimental study that twenty healthy women participated. For assessing automatic response of trunk extensor and abdominal muscles before and after the fatigue task, electromyographic activities of 6 muscles: thorasic erector spine (TES), lumbar erector spine (LES), lumbar multifidus (LMF), transverse abdominis/ internal oblique (TrA/IO), rectus abdominis (RA) and external oblique (EO) were recorded in standing position with no load and symmetric axial loads equal to 25% of their body weights. Statistical analysis showed that all the abdominal muscles activity decreased with axial loads after performing fatigue task but trunk extensor activity remained constant. Results of the current study indicated that muscle recruitment strategies changed with muscle fatigue and load bearing, therefore risks of tissue injury may increase in fatigue conditions.

  17. CURBSIDE CONSULTATION IN KNEE ARTHROPLASTY: 49 CLINICAL QUESTIONS

    Directory of Open Access Journals (Sweden)

    Craig J. Della Vale

    2008-12-01

    Full Text Available A user- friendly reference for decision making in complicated cases of knee arthroplasty desingned in a question and answers format composed of articles containing current concepts and preferences of experts in total knee replacement surgery, enhanced by several images, diagrams and references and written in the form of a casual advice by Craig J. Della Vale, MD. and his collaborators. PURPOSE By this practical reference of knee arthroplasty, the editor and the contributors have aimed providing straightforward and brief answers, evidence-based advices, their preference and opinions containing current concepts for unanswered questions about complicated cases in total knee replacement surgery which are often controversial and not addressed clearly in traditional knee arthroplasty references. FEATURES There are 49 subjects each written by a different expert designed in 4 sections in a question and answers format including several images and diagrams and also essential references at the end of each article. In the first section preoperative questions is subjected including indications, unicompartmental osteoarthritis of the knee, patient with vascular problems, donating blood, bilateral arthroplasty, patellar resurfacing, range of motion, bearing surface, contraindications, teaching class for patients prior surgery. The second section is about intraoperative questions including skin incision, patella femoral maltracking, femoral component rotation, tibial component rotation, lateral release, femoral component sizing, flexion instability, varus deformity, and valgus deformity, tightness in extension, iatrogenic MCL injury, antibiotic-loaded cement, and perioperative pain. The third section subjects postoperative questions including wound drainage, preventing tromboembolic events, vascular complications, foot drop, manipulation under anesthesia, patella fractures, supracondylar femur fractures, acute extensor mechanism disruptions. In the fourth

  18. Y BALANCE TEST™ ANTERIOR REACH SYMMETRY AT THREE MONTHS IS RELATED TO SINGLE LEG FUNCTIONAL PERFORMANCE AT TIME OF RETURN TO SPORTS FOLLOWING ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION.

    Science.gov (United States)

    Garrison, J Craig; Bothwell, James M; Wolf, Gina; Aryal, Subhash; Thigpen, Charles A

    2015-10-01

    Restoration of symmetrical strength, balance, and power following anterior cruciate ligament reconstruction (ACL-R) are thought to be important factors for successful return to sports. Little information is available regarding early rehabilitation outcomes and achieving suggested limb indices of 90% on functional performance measures at the time of return to sports (RTS). To examine the relationship between symmetry of the anterior reach of the Y Balance Test™ at 12 weeks and functional performance measures at time of return to sports after anterior cruciate ligament (ACL) reconstruction. Retrospective Cohort. Forty subjects (mean ± SD age, 17.2 ± 3.8 years) who were in the process of rehabilitation following ACL reconstruction. Each subject volunteered and was enrolled in the study during physical therapy following ACL-R. Participants averaged two visits per week in physical therapy until the time of testing for RTS. The Y Balance Test™ was assessed at 12 weeks. Participants completed a battery of tests at RTS (6.4 ± 1.1 months) including triple hop distance (THD), single hop distance (SHD), isometric knee extension strength (KE), and the Vail Sport Test™. Side to side difference was calculated for the Y Balance Test™ anterior reach and limb symmetry indices (LSI) were computed for THD, SHD, and KE. Multiple regression models were used to study the relationship between variables at 12 weeks and RTS while controlling for age, gender, type of graft, and pain score. In addition, subjects were dichotomized based on a side-to-side Y Balance anterior reach difference into high risk (>4 cm) or low risk (≤4 cm) categories. A receiver operating characteristic (ROC) curve was used to identify individuals at 12 weeks who do not achieve 90% limb symmetry indices at time of RTS testing. . A statistically significant association was seen between Y Balance ANT at 12 weeks and SHD at RTS (β = -1.46, p = 0.0005, R(2) = 0.395), THD at RTS

  19. Septic arthritis of the knee following anterior cruciate ligament reconstruction

    Directory of Open Access Journals (Sweden)

    Matjaz Sajovic

    2009-04-01

    Full Text Available Septic arthritis of the knee is a rare complication after arthroscopic anterior cruciate ligament reconstruction, and the most appropriate treatment is unclear. All case series reported so far have been retrospective, and case numbers of septic arthritis have ranged from 4 to 11. From a consecutive case series of 1,283 patients who underwent arthroscopic anterior cruciate ligament reconstruction between January 1997 and May 2008, we report on 3 patients (0.23% with post-operative septic arthritis. All patients had acute infection (≤ 2 weeks, bacterial cultures showed Staphylococcus species in 2 patients, while the bacterial culture was negative in the third. All of them underwent immediate arthroscopic debridement and lavage with continuous irrigation, as well as antibiotic treatment. The results were evaluated with physical and radiographic examination, functional testing, KT-2000, Lysholm and Tegner scales. The infection was successfully eradicated without further surgical treatment and the ligament graft was retained in all patients. Follow-up, at an average of 33 months, revealed that the patients had full symmetric knee range of motion and no effusion. The average Lysholm score was 91 points. In the patient with a lower subjective score, radiographs demonstrated patellofemoral joint-space narrowing, which is most probably in correlation with his anterior knee pain problems and lower activity level. The 134 N KT-2000 arthrometer side-to-side differences averaged 13 mm. Their performance in the single-legged hop test gave excellent results. The goals of treatment for septic arthritis after anterior cruciate ligament reconstruction are, primarily, to protect the articular cartilage and, secondly, to protect the graft. Through early diagnosis and prompt treatment, the infection can be successfully eradicated, with stability of the knee and full range of motion achieved.

  20. DIFFERENCES IN BIOMECHANICAL PROPERTIES OF KNEE EXTENSOR REBOUND WITH THE DIFFERENT SURFACE ELASTICITY

    Directory of Open Access Journals (Sweden)

    Katarina Herodek

    2013-07-01

    Full Text Available The sample includes 40 subjects of both sexes: male (20 and female (20 population of students of the Faculty of Sport and Physical Education, University of Nis. The research involves the application of the rebound in gymnastics with two different heights (40 and 50cm on three different surfaces of elasticity: hard, demyelastic and elastic surface. The subject of the research were the dynamic parameters of movement laid down from Drop Jump (DJ with Myotest device and in the following parameters: height (in cm, power (in W/ kg, force (in N/ kg and speed (cm/ s. Using canonical-discrimination analysis showed no statistically significant differences in the performance jump of hard and demyelastic surface from a height 40 cm and 50 cm for men and women, thethe studied parameters (height, strength ,power and speed of the bounce . Revealed a statistically significant difference in performance with the elastic rebound surface elevations of 40 cm and 50 cm for men and women (p = 0.00. Of the examined parameters was obtained that there are significant differences in the Force reflection to the significance level of 98% (0.0255 and the power of reflection on the significance level of 100% (0.0009 in men. In women of the examined parameters was obtained a statistically significant difference in the strength of the rebound only from positions of 40cm and 50cm and 100% (0.0075.

  1. Fatigue resistance of the knee extensor muscles is not reduced in post-polio syndrome

    NARCIS (Netherlands)

    Voorn, E.L.; Beelen, A.; Gerrits, K.H.L.; Nollet, F.; de Haan, A.

    2013-01-01

    The present study investigated whether intrinsic fatigability of the muscle fibers is reduced in patients with post-polio syndrome (PPS). This may contribute to the muscle fatigue complaints reported by patients with PPS. For this purpose, we assessed contractile properties and fatigue resistance of

  2. Dynamometry of the knee extensors; isometric and isokinetic testing in healthy subjects and patients

    OpenAIRE

    Stam, Henk

    1990-01-01

    textabstractIn rehabilitation medicine one is concerned with the consequences of diseases, congenital deformations and trauma. On the level of functions and structures the consequences consist of impairments of muscle strength, sensibility, co-ordination, etc. These impairments may cause disabilities like restricted ambulation, problems with self-care, etc. In rehabilitation one feels a need to measure the impairments in a reliable way, in order to assess the effects of certain training progr...

  3. ALTERATION OF MUSCLE FUNCTION AFTER ELECTRICAL STIMULATION BOUT OF KNEE EXTENSORS AND FLEXORS

    Directory of Open Access Journals (Sweden)

    Marc Vanderthommen

    2012-12-01

    Full Text Available The purpose was to study the effects on muscle function of an electrical stimulation bout applied unilaterally on thigh muscles in healthy male volunteers. One group (ES group, n = 10 received consecutively 100 isometric contractions of quadriceps and 100 isometric contractions of hamstrings (on-off ratio 6-6 s induced by neuromuscular electrical stimulations (NMES. Changes in muscle torque, muscle soreness (0-10 VAS, muscle stiffness and serum creatine kinase (CK activity were assessed before the NMES exercise (pre-ex as well as 24h (d+1, 48h (d+2 and 120h (d+5 after the bout. A second group (control group, n = 10 were submitted to the same test battery than the ES group and with the same time-frame. The between-group comparison indicated a significant increase in VAS scores and in serum levels of CK only in the ES group. In the ES group, changes were more pronounced in hamstrings than in quadriceps and peaked at d+2 (quadriceps VAS scores = 2.20 ± 1.55 a.u. (0 at pre-ex; hamstrings VAS scores = 3.15 ± 2.14 a.u. (0 at pre-ex; hip flexion angle = 62 ± 5° (75 ± 6° at pre-ex; CK activity = 3021 ± 2693 IU·l-1 (136 ± 50 IU·l-1 at pre-ex. The results of the present study suggested the occurrence of muscle damage that could have been induced by the peculiar muscle recruitment in NMES and the resulting overrated mechanical stress. The sensitivity to the damaging effects of NMES appeared higher in the hamstrings than in quadriceps muscles

  4. Dynamometry of the knee extensors; isometric and isokinetic testing in healthy subjects and patients

    NARCIS (Netherlands)

    H.J. Stam (Henk)

    1990-01-01

    textabstractIn rehabilitation medicine one is concerned with the consequences of diseases, congenital deformations and trauma. On the level of functions and structures the consequences consist of impairments of muscle strength, sensibility, co-ordination, etc. These impairments may cause

  5. Reflex and Non-Reflex Torque Responses to Stretch of the Human Knee Extensors

    National Research Council Canada - National Science Library

    Mrachacz-Kersting, N

    2001-01-01

    .... The quadriceps muscles were stretched at various background torques, produced either voluntarily or electrically and thus the purely reflex-mediated torque could be calculated. The contribution of the reflex mediated stiffness initially low, increased with increasing background torques for the range of torques investigated.

  6. Effect of temperature on skeletal muscle energy turnover during dynamic knee-extensor exercise in humans

    DEFF Research Database (Denmark)

    Ferguson, R.A.; Krustrup, Peter; Kjær, Michael

    2006-01-01

    (C) and elevated muscle temperature (HT) through passive heating. Thigh oxygen uptake (V(O2)) was determined from measurements of thigh blood flow and femoral arterial-venous differences for oxygen content. Anaerobic energy turnover was estimated from measurements of lactate release as well as muscle...

  7. Preoperative Strength Training for Elderly Patients Awaiting Total Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    D. M. van Leeuwen

    2014-01-01

    Full Text Available Objective. To investigate the feasibility and effects of additional preoperative high intensity strength training for patients awaiting total knee arthroplasty (TKA. Design. Clinical controlled trial. Patients. Twenty-two patients awaiting TKA. Methods. Patients were allocated to a standard training group or a group receiving standard training with additional progressive strength training for 6 weeks. Isometric knee extensor strength, voluntary activation, chair stand, 6-minute walk test (6MWT, and stair climbing were assessed before and after 6 weeks of training and 6 and 12 weeks after TKA. Results. For 3 of the 11 patients in the intensive strength group, training load had to be adjusted because of pain. For both groups combined, improvements in chair stand and 6MWT were observed before surgery, but intensive strength training was not more effective than standard training. Voluntary activation did not change before and after surgery, and postoperative recovery was not different between groups (P>0.05. Knee extensor strength of the affected leg before surgery was significantly associated with 6-minute walk (r=0.50 and the stair climb (r−=0.58, P<0.05. Conclusion. Intensive strength training was feasible for the majority of patients, but there were no indications that it is more effective than standard training to increase preoperative physical performance. This trial was registered with NTR2278.

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

    Science.gov (United States)

    Damiano, Diane L.; Bulea, Thomas C.

    2016-01-01

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

  9. Weightlifting performance is related to kinematic and kinetic patterns of the hip and knee joints.

    Science.gov (United States)

    Kipp, Kristof; Redden, Josh; Sabick, Michelle B; Harris, Chad

    2012-07-01

    The purpose of this study was to investigate the correlations between biomechanical outcome measures and weightlifting performance. Joint kinematics and kinetics of the hip, knee, and ankle were calculated while 10 subjects performed a clean at 85% of 1 repetition maximum (1RM). Kinematic and kinetic time-series patterns were extracted with principal components analysis. Discrete scores for each time-series pattern were calculated and used to determine how each pattern was related to body mass-normalized 1RM. Two hip kinematic and 2 knee kinetic patterns were significantly correlated with relative 1RM. The kinematic patterns captured hip and trunk motions during the first pull and hip joint motion during the movement transition between the first and second pulls. The first kinetic pattern captured a peak in the knee extension moment during the second pull. The second kinetic pattern captured a spatiotemporal shift in the timing and amplitude of the peak knee extension moment. The kinematic results suggest that greater lift mass was associated with steady trunk position during the first pull and less hip extension motion during the second-knee bend transition. Further, the kinetic results suggest that greater lift mass was associated with a smaller knee extensor moments during the first pull, but greater knee extension moments during the second pull, and an earlier temporal transition between knee flexion-extension moments at the beginning of the second pull. Collectively, these results highlight the importance of controlled trunk and hip motions during the first pull and rapid employment of the knee extensor muscles during the second pull in relation to weightlifting performance.

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

    Science.gov (United States)

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

    2017-08-01

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

  11. The Positive Benefits of Negative Movement Patterns Following Total Knee Arthroplasty.

    Science.gov (United States)

    Christensen, Jesse C; Foreman, K Bo; LaStayo, Paul C

    2018-01-01

    Eccentric (negative) resistance exercise of the legs using specialized machines has been reported to be useful and often superior to standard exercise following total knee arthroplasty (TKA). Movements that utilize body mass and gravity as a mode of eccentric resistance exercise in a more pragmatic rehabilitation paradigm may also be useful in reversing chronic muscle impairments observed years following surgery. This study explores whether an eccentrically biased, body mass resistance exercise induces greater magnitude of sagittal plane extensor angular impulse of the support torque and individual net joint torque contributions during both squatting and lunging movement patterns 6 weeks following TKA. Cross-sectional laboratory-based study design including 10 patients following primary unilateral TKA (6.5 ± 0.8 weeks.). All patients completed 3 trials of the squat and lunge movement pattern under both a concentric and an eccentric condition. Extensor angular impulse of the support torque and net joint torque contributions were calculated by integrating the joint torque versus time curves. A Two-way analysis of covariance was conducted and contracts of clinical interest were computed using Wald posttest. P Values for all pairwise comparisons were adjusted for multiplicity using Bonferroni multiple comparison procedure. The eccentric condition, compared to the concentric condition, displayed larger magnitude of extensor angular impulse during both the squat ( P movement patterns for the support torques. Similarly, the eccentric condition, compared to the concentric condition, displayed larger magnitude of extensor angular impulse of the hip, knee, and ankle ( P movement patterns. Eccentrically biased, body mass movement exercises can produce higher levels of extensor angular impulse on the surgical limb in patients early after TKA. Patients in this study were able to tolerate the higher extensor angular impulse demands and performed the eccentrically biased

  12. The relationship between bilateral knee muscle strength and gait performance after stroke: the predictive value for gait performance

    Science.gov (United States)

    Watanabe, Makoto; Suzuki, Makoto; Sugimura, Yuko; Kawaguchi, Takayuki; Watanabe, Aki; Shibata, Kazuhiko; Fukuda, Michinari

    2015-01-01

    [Purpose] The purpose of this study was to assess the relationships between bilateral knee extension strengths and gait performance in subjects with poststroke hemiparesis and to predict gait performance by the paretic and nonparetic knee extension strength. [Subjects and Methods] This was a correlational study in which 238 consecutive inpatients with poststroke hemiparesis were enrolled. Knee extensor muscle strengths in paretic and nonparetic lower limbs were measured with a handheld dynamometer, and the presence or absence of impaired gait was also determined. [Results] The mean strength in the paretic lower limb was 0.90 Nm/kg, and that in the nonparetic lower limb was 1.24 Nm/kg. Discriminant analysis classified the difference between the possibility and impossibility of gait by knee extensor muscle strength (standardized discriminant coefficient: paretic, 1.32; nonparetic, 0.55). Thus, paretic and nonparetic knee extension strengths were integrated in the strength index. A threshold level of 2.0 provided the best balance between positive and negative predictive values for the strength index. [Conclusion] The results indicated that both paretic and nonparetic knee extension strengths were related to gait performance. The strength index deduced from bilateral knee extension strengths may serve as a clinically meaningful index for rehabilitation assessment and training. PMID:26644680

  13. Quadriceps Tendon Rupture and Contralateral Patella Tendon Avulsion Post Primary Bilateral Total Knee Arthroplasty: A Case Report

    Directory of Open Access Journals (Sweden)

    Gaurav Sharma

    2016-07-01

    Full Text Available Background: Extensor mechanism failure secondary to knee replacement could be due to tibial tubercle avulsion, Patellar tendon rupture, patellar fracture or quadriceps tendon rupture. An incidence of Patella tendon rupture of 0.17% and Quadriceps tendon rupture of around 0.1% has been reported after Total knee arthroplasty. These are considered a devastating complication that substantially affects the clinical results and are challenging situations to treat with surgery being the mainstay of the treatment. Case Description: We report here an interesting case of a patellar tendon rupture of one knee and Quadriceps tendon rupture of the contralateral knee following simultaneous bilateral knee replacement in a case of inflammatory arthritis patient. End to end repair for Quadriceps tear and augmentation with Autologous Hamstring tendon graft was done for Patella tendon rupture. OUTCOME: Patient was followed up for a period of 1 year and there was no Extension lag with a flexion of 100 degrees in both the knees. DISCUSSION: The key learning points and important aspects of diagnosing these injuries early and the management techniques are described in this unique case of bilateral extensor mechanism disruption following knee replacements.

  14. Effects of changes in skiing posture on the kinetics of the knee joint.

    Science.gov (United States)

    Koyanagi, Maki; Shino, Konsei; Yoshimoto, Yoji; Inoue, Satoru; Sato, Mutsumi; Nakata, Ken

    2006-01-01

    This study was performed to investigate the effects of changes in the skiing posture on mechanical stress across the knee joint. The aim of the present study was to establish a safer form of skiing for the prevention of injury to the anterior cruciate ligament of the knee (ACL). Ten healthy volunteers were placed on a force plate on an artificial slope, and assumed forward and backward bending postures with a single leg by changing their centre of gravity. The knee flexion angles were limited to approximately 30 degrees by orthotics in each posture. Joint moments of the lower extremity were analyzed using a motion analysis system, and the muscle activities of the lower extremity were recorded by EMG and digitised to integrated EMG in each posture. In addition, extrusion of the lower leg by the boot was measured using a force sensor sheet inserted behind the calf. We found that the extension moment of the hip and ankle joints, and muscular activity of the hamstrings were increased in forward bending, whereas the extension moment of the knee and muscular activity of the quadriceps were decreased. Conversely, the muscular activity of the quadriceps, the flexion moment of the hip, extension moment of the knee joint, and pressure of the boot were increased in backward bending, whereas muscular activity of the hamstrings was decreased. The dependency on the hamstrings increased in forward bending in a skiing posture on a slope with slight knee flexion. Therefore, forward bending seemed to be an advantageous posture for the prevention of ACL injury. Conversely, in a backward bending skiing posture, the extension moment of the knee joint produced by muscle contraction of the quadriceps also increased imbalance in the hamstrings. The results of this study suggest that the internal force exerted by the quadriceps, in addition to the passive factor of extrusion of the lower leg by the boot, may contribute to non-contact ACL injury in a backward bending posture while skiing.

  15. Is Pain in One Knee Associated with Isometric Muscle Strength in the Contralateral Limb?: Data From the Osteoarthritis Initiative.

    Science.gov (United States)

    Steidle-Kloc, Eva; Wirth, Wolfgang; Glass, Natalie A; Ruhdorfer, Anja; Cotofana, Sebastian; Eckstein, Felix; Segal, Neil A

    2015-10-01

    Knee pain and muscle weakness confer risk for knee osteoarthritis incidence and progression. The purpose of this study was to determine whether unilateral knee pain influences contralateral thigh muscle strength. Of 4796 Osteoarthritis Initiative participants, 224 (mean ± SD age, 63.9 ± 8.9 yrs) cases could be matched to a control. Cases were defined as having unilateral knee pain (numerical rating scale, ≥ 4/10; ≥infrequent pain) and one pain-free knee (numerical rating scale, 0-1; ≤infrequent pain; Western Ontario and McMaster Universities Arthritis Index, ≤ 1). Controls were defined as having bilaterally pain-free knees (numerical rating scale, 0-1; ≤infrequent pain; Western Ontario and McMaster Universities Arthritis Index, ≤ 1). Maximal isometric muscle strength (N) was compared between limbs in participants with unilateral pain (cases) as well as between pain-free limbs of cases and controls. Knee extensor/flexor strength in pain-free limbs of the cases was lower than that in bilaterally pain-free controls (-5.5%/-8.4%; P = 0.043/P = 0.022). Within the cases, maximum extensor/flexor strength was significantly lower in the painful limb than in the pain-free limb (-6.3%/4.1%; P strength in limbs without knee pain is associated with the pain status of the contralateral knee. The strength difference between unilateral pain-free cases and matched bilateral pain-free controls was similar to that between limbs in persons with unilateral knee pain. Lower strength caused by contralateral knee pain might be centrally mediated.

  16. IS PAIN IN ONE KNEE ASSOCIATED WITH ISOMETRIC MUSCLE STRENGTH IN THE CONTRALATERAL LIMB? - DATA FROM THE OSTEOARTHRITIS INITIATIVE (OAI)

    Science.gov (United States)

    Steidle, E.; Wirth, W.; Glass, N.; Ruhdorfer, A.; Cotofana, S.; Eckstein, F.; Segal, N. A.

    2014-01-01

    Objective Knee pain and muscle weakness confer risk for knee osteoarthritis incidence and progression. The purpose of this study was to determine whether unilateral knee pain influences contralateral thigh muscle strength. Design Of 4796 Osteoarthritis Initiative participants, 224 (mean±SD age 63.9±8.9 years) cases could be matched to a control. Cases were defined as having unilateral knee pain (numerical rating scale (NRS)≥4/10; ≥infrequent pain) and one pain-free knee (NRS 0–1; ≤infrequent pain; WOMAC≤1). Controls were defined as having bilaterally pain-free knees (NRS 0–1; ≤infrequent pain; WOMAC≤1). Maximal isometric muscle strength [N] was compared between limbs in participants with unilateral pain (cases), and between pain-free limbs of cases and controls. Results Knee extensor/flexor strength in pain-free limbs of cases was lower than in bilaterally pain-free controls (−5.5%/–8.4%; p=0.043/p=0.022). Within cases, maximum extensor/flexor strength was significantly lower in the painful than in the pain-free limb (−6.4%/4.1%; pstrength in limbs without knee pain is associated with the pain status of the contralateral knee. The strength difference between unilateral pain-free cases and matched bilateral pain-free controls was similar to that between limbs in persons with unilateral knee pain. Lower strength due to contralateral knee pain might be centrally mediated. PMID:25768069

  17. Varus and Valgus Alignment and Incident and Progressive Knee Osteoarthritis

    Science.gov (United States)

    Sharma, Leena; Song, Jing; Dunlop, Dorothy; Felson, David; Lewis, Cora E.; Segal, Neil; Torner, James; Cooke, T. Derek V.; Hietpas, Jean; Lynch, John; Nevitt, Michael

    2010-01-01

    Objective Varus and valgus alignment increase, respectively, medial and lateral tibiofemoral load. Alignment was associated with tibiofemoral osteoarthritis progression in previous studies; an effect on risk of incident osteoarthritis is less certain. We tested whether alignment influences the risk of incident and progressive radiographic tibiofemoral osteoarthritis. Methods In an observational, longitudinal study of the MOST (Multicenter Osteoarthritis Study) cohort, full-limb x-rays to measure alignment were acquired at baseline and knee x-rays were acquired at baseline and 30 months. Varus alignment was defined as ≤ 178° and valgus as ≥ 182°. Using logistic regression and GEE, we examined the association of baseline alignment and incident osteoarthritis at 30 months (in knees without osteoarthritis at baseline), and alignment and osteoarthritis progression (in knees with baseline osteoarthritis). All analyses were adjusted for age, gender, BMI, knee injury, laxity, and extensor strength, with neutral knees as referent. Results 2958 knees (1752 participants) were without osteoarthritis at baseline. Varus (adj. OR 1.49, 95% CI 1.06, 2.10) but not valgus alignment was associated with incident osteoarthritis. 1307 knees (950 participants) had osteoarthritis at baseline. Varus alignment was associated with a greater risk of medial osteoarthritis progression (adj. OR 3.59, 95% CI 2.62, 4.92) and a reduced risk of lateral progression, and valgus with a greater risk of lateral progression (adj. OR 4.85, 95% CI 3.17, 7.42) and a reduced risk of medial progression. Conclusion Varus but not valgus alignment increased the risk of incident tibiofemoral osteoarthritis. In knees with osteoarthritis, varus and valgus alignment each increased the risk of progression in the biomechanically stressed compartment and reduced the risk of progression in the unloaded compartment. PMID:20511608

  18. Ankle and knee kinetics between strike patterns at common training speeds in competitive male runners.

    Science.gov (United States)

    Kuhman, Daniel; Melcher, Daniel; Paquette, Max R

    2016-01-01

    The purpose of this study was to investigate the interaction of foot strike and common speeds on sagittal plane ankle and knee joint kinetics in competitive rear foot strike (RFS) runners when running with a RFS pattern and an imposed forefoot strike (FFS) pattern. Sixteen competitive habitual male RFS runners ran at two different speeds (i.e. 8 and 6 min mile(-1)) using their habitual RFS and an imposed FFS pattern. A repeated measures analysis of variance was used to assess a potential interaction between strike pattern and speed for selected ground reaction force (GRF) variables and, sagittal plane ankle and knee kinematic and kinetic variables. No foot strike and speed interaction was observed for any of the kinetic variables. Habitual RFS yielded a greater loading rate of the vertical GRF, peak ankle dorsiflexor moment, peak knee extensor moment, peak knee eccentric extensor power, peak dorsiflexion and sagittal plane knee range of motion compared to imposed FFS. Imposed FFS yielded greater maximum vertical GRF, peak ankle plantarflexor moment, peak ankle eccentric plantarflexor power and sagittal plane ankle ROM compared to habitual RFS. Consistent with previous literature, imposed FFS in habitual RFS reduces eccentric knee extensor and ankle dorsiflexor involvement but produce greater eccentric ankle plantarflexor action compared to RFS. These acute differences between strike patterns were independent of running speeds equivalent to typical easy and hard training runs in competitive male runners. Current findings along with previous literature suggest differences in lower extremity kinetics between habitual RFS and imposed FFS running are consistent among a variety of runner populations.

  19. Knee Arthrodesis After Failure of Knee Arthroplasty

    DEFF Research Database (Denmark)

    Gottfriedsen, Tinne B; Morville Schrøder, Henrik; Odgaard, Anders

    2016-01-01

    BACKGROUND: Arthrodesis is considered a salvage procedure after failure of a knee arthroplasty. Data on the use of this procedure are limited. The purpose of this study was to identify the incidence, causes, surgical techniques, and outcomes of arthrodesis after failed knee arthroplasty in a nati......BACKGROUND: Arthrodesis is considered a salvage procedure after failure of a knee arthroplasty. Data on the use of this procedure are limited. The purpose of this study was to identify the incidence, causes, surgical techniques, and outcomes of arthrodesis after failed knee arthroplasty...

  20. [Isolated traumatic dislocation of the extensor carpi ulnaris tendon].

    Science.gov (United States)

    Loty, B; Meunier, B; Mazas, F

    1986-01-01

    The authors describe one case of post-traumatic dislocation of the extensor carpi ulnaris tendon. They found eleven other cases reported in the literature. The type of lesion should be looked for in cases of trauma to the wrist without a bony lesion. The treatment should be surgical when function is impaired, either shortly after the initial trauma or if the dislocation becomes habitual. The aim is to reconstruct a tendon sheath. The results were generally satisfactory.

  1. An anomalous accessory extensor proprius indicis muscle: A case report

    Directory of Open Access Journals (Sweden)

    Mustafa Kurklu

    2013-12-01

    Full Text Available Variations related to tendon insertion and musculotendinous junction of the extensor proprius indicis muscle are commonly encountered. An anomalous extensor indicis proprius muscle (EIP tendon was detected in a fifty-year-old female cadaver during routine dissection of the right upper extremity. The body of tendon was initiated from the posterior ulna as a one muscle body, then continued as two separate muscle bodies and tendons and finally they were separated into two slips after passing the fourth dorsal compartment. As a radial part, it was divided into two slips at the level of the first metacarpophalangeal joint, and conjugated with the extensor pollicis longus (EPL muscle. Then, as an ulnar part, it was terminated at the radial side of the lateral band of the second metacarpophalangeal joint. Familiarity with the normal anatomy and variations of the tendons may help to prevent confusion and mistakes during tendon repairs, and tendon transfers. [Hand Microsurg 2013; 2(3.000: 122-124

  2. Knee Injuries and Disorders

    Science.gov (United States)

    ... cartilage in the knee gradually wears away, causing pain and swelling. Injuries to ligaments and tendons also cause knee problems. A common injury is to the anterior cruciate ligament (ACL). You usually injure your ACL ...

  3. Knee braces - unloading

    Science.gov (United States)

    ... most people talk about the arthritis in their knees, they are referring to a type of arthritis ... is caused by wear and tear inside your knee joints. Cartilage, the firm, rubbery tissue that cushions ...

  4. Partial knee replacement - slideshow

    Science.gov (United States)

    ... medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series—Normal anatomy To use the sharing features ... M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited by ...

  5. Knee joint replacement - slideshow

    Science.gov (United States)

    ... medlineplus.gov/ency/presentations/100088.htm Knee joint replacement - series—Normal anatomy To use the sharing features ... M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited by ...

  6. What Are Knee Problems?

    Science.gov (United States)

    ... to stand on it. The medial and lateral collateral ligaments are usually injured by a blow to ... This can help your knee(s) without increasing the risk of injury or further damage. As a general ...

  7. Tenosynovial (Extra-articular) Chondromatosis of the Extensor Digitorum Longus Tendon and Synovial Chondromatosis of the Ankle: Treated by Extensor Digitorum Longus Tendoscopy and Ankle Arthroscopy.

    Science.gov (United States)

    Lui, Tun Hing

    2015-10-01

    Synovial chondromatosis is a rare pathology in the foot and ankle region. We present a case of concomitant tenosynovial chondromatosis of the extensor digitorum longus tendon and synovial chondromatosis of the ankle, which was successfully treated by extensor digitorum tendon tendoscopy and ankle arthroscopy. Therapeutic, Level IV: Case study. © 2014 The Author(s).

  8. Loss of knee-extension strength is related to knee swelling after total knee arthroplasty

    DEFF Research Database (Denmark)

    Holm, Bente; Kristensen, Morten T; Bencke, Jesper

    2010-01-01

    To examine whether changes in knee-extension strength and functional performance are related to knee swelling after total knee arthroplasty (TKA).......To examine whether changes in knee-extension strength and functional performance are related to knee swelling after total knee arthroplasty (TKA)....

  9. Subluxation of the Extensor Carpi Ulnaris Tendon Associated with the Extensor Digitorum Tendon Subluxation of the Long Finger

    Science.gov (United States)

    Kim, Byung-Sung; Yoon, Hong-Gi; Kim, Hyung-Tae; Park, Kang-Hee; Kim, Chang-Geun

    2013-01-01

    A twenty-year-old male visited our clinic with wrist and long finger metacarpophalangeal (MP) joint pain. Dynamic ultrasonography revealed sagittal band (SB) ulnar subluxation and extensor carpi ulnaris (ECU) volar subluxation. Magnetic resonance imaging showed longitudinal splitting and dislocation of the volar half slip of the ECU tendon. The redundant radial SB was augmented and ECU sheath was advanced to the periosteum using suture anchors. He was able to perform his previous activities at the last follow-up. We encountered a case of "simulateous" ECU dislocation with extensor tendon subluxation of the long finger at the MP joint. Therefore, we report this case with a review of the relevant literature. PMID:23467477

  10. Differences in the Dominant and Non-Dominant Knee Valgus Angle in Junior Elite and Amateur Soccer Players after Unilateral Landing

    Directory of Open Access Journals (Sweden)

    Oliver Ludwig

    2017-02-01

    Full Text Available More than 70% of all knee injuries in soccer occur in non-contact situations. It is known that increased lower limb dynamic knee valgus is associated with such situations. Little has been found out about differences in knee kinematics of the dominant (kicking and non-dominant (supporting leg during a single leg landing. A total of 114 male adolescent soccer players (age 14.6 ± 1.1 years from elite (N = 66 and amateur soccer clubs (N = 48 performed a single leg drop landing down from a box. For each leg, the two-dimensional dynamic knee valgus angle (DKVA was calculated. Paired t-tests were used to statistically determine significant differences between dominant and non-dominant leg DKVA, and t-tests were calculated between the two performance groups. Statistically significant differences (p < 0.05 were identified for the DKVA between the dominant and non-dominant leg for both amateur and elite players, showing a greater DKVA for the dominant leg. Group differences for the DKVA between amateur and elite players were not found, neither for the dominant, nor for the non-dominant leg. It can be concluded that the non-dominant leg showed more stable dynamics than the dominant leg during unilateral landing regardless of the player’s performance level. This could be due to adaptions to sport-specific requirements. Therefore, it is recommended that programs to prevent knee injuries among soccer players consider the dynamics of each leg individually.

  11. Total knee arthroplasty

    DEFF Research Database (Denmark)

    Schrøder, Henrik M.; Petersen, Michael M.

    2016-01-01

    Total knee arthroplasty (TKA) is a successful treatment of the osteoarthritic knee, which has increased dramatically over the last 30 years. The indication is a painful osteoarthritic knee with relevant radiographic findings and failure of conservative measures like painkillers and exercise...

  12. The Effect of the Mulligan Knee Taping Technique on Patellofemoral Pain and Lower Limb Biomechanics.

    Science.gov (United States)

    Hickey, Anne; Hopper, Diana; Hall, Toby; Wild, Catherine Y

    2016-05-01

    Patellofemoral pain (PFP) affects 25% of the general population, occurring 2 times more often in females compared with males. Taping is a valuable component of the management plan for altering lower limb biomechanics and providing pain relief; however, the effects of alternative taping techniques, such as Mulligan knee taping, appear yet to be researched. To determine whether the Mulligan knee taping technique altered levels of perceived knee pain and lower limb biomechanics during a single-legged squat (SLSq) in adult females with PFP. Controlled laboratory study. A total of 20 female patients with PFP, aged 18 to 35 years, participated in this study. Participants performed 3 to 5 SLSq on their most symptomatic limb during a taped (Mulligan knee taping technique) and nontaped (control) condition. During the eccentric phase of the SLSq, the 3-dimensional kinematics (250 Hz) of the knee and hip and the ground-reaction forces (1000 Hz) and muscle activation patterns (1000 Hz) of the gluteus medius, vastus lateralis, and vastus medialis oblique were measured. Participants' perceived maximum knee pain was also recorded after the completion of each squat. Between-condition differences were found for hip kinematics and gluteus medius activation but not for kinetics or vastus medialis oblique and vastus lateralis muscle activity (timing and activation). Compared with the nontaped condition, the Mulligan knee taping technique significantly (P = .001) reduced perceived pain during the SLSq (mean ± SD: 2.29 ± 1.79 and 1.29 ± 1.28, respectively). In the taped condition compared with the control, the onset timing of the gluteus medius occurred significantly earlier (120.6 ± 113.0 and 156.6 ± 91.6 ms, respectively; P = .023) and peak hip internal rotation was significantly reduced (6.38° ± 7.31° and 8.34° ± 7.92°, respectively; P = .002). The Mulligan knee taping technique successfully reduced knee pain in participants with PFP. This is the first study to establish a

  13. Delayed rupture of the extensor hallucis longus and extensor digitorum communis tendons after breaching the anterior capsule with a radiofrequency probe during ankle arthroscopy: a case report.

    Science.gov (United States)

    Tuncer, Serdar; Aksu, Neslihan; Isiklar, Ugur

    2010-01-01

    A 40-year-old man with early arthritis, loose bodies, and anterolateral joint impingement symptoms in his left ankle, which was refractory to noninvasive therapeutic modalities for 1 year, underwent ankle arthroscopy and radiofrequency thermal ablation. The anterior capsule of the ankle joint was breached by the radiofrequency probe while the loose bodies were removed from the anterior recess, exposing the extensor tendons and resulting in a delayed spontaneous rupture of the extensor hallucis longus tendon and extensor tendons to the second and third toes. The extensor hallucis longus tendon was repaired with a semitendinosus tendon graft, and extensor digitorum tendons underwent primary repair. The patient regained full function and was symptom free 1 year after surgery. Copyright 2010 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  14. Hip muscle activation and knee frontal plane motion during weight bearing therapeutic exercises.

    Science.gov (United States)

    Lubahn, Amanda J; Kernozek, Thomas W; Tyson, Tiffany L; Merkitch, Kenneth W; Reutemann, Paul; Chestnut, John Mark

    2011-06-01

    Hip abduction strengthening exercises may be critical in the prevention and rehabilitation of both overuse and traumatic injuries where knee frontal plane alignment is considered to be important. The purpose of the current investigation was to examine the muscular activation of the gluteus maximus and gluteus medius during the double-leg squat (DLS), single-leg squat (SLS), or front step-up (FSU), and the same exercises when an added load was used to pull the knee medially. Eighteen healthy females (ages 18-26) performed six exercises: DLS, DLS with load, FSU, FSU with load, SLS, and SLS with load. Integrated and peak surface electromyography of gluteus maximus and gluteus medius of the dominant leg were recorded and normalized. Motion analysis was used to measure knee abduction angle during each exercise. SLS had the highest integrated and peak activation for both muscles, regardless of load. Adding load, only increased DLS integrated gluteus maximus activation (p=0.019). Load did not increase integrated gluteus medius or peak gluteus maximus activation. Adding load decreased SLS peak gluteus medius activation (p=0.003). Adding load increased peak knee abduction angle during DLS (p=0.013), FSU (p=0.000), and SLS (p=0.011). Overall, the SLS was most effective exercise for activating the gluteus maximus and gluteus medius. Applied knee load does not appear to increase muscle activation during SLS and FSU. DLS with an applied load may be more beneficial in activating the gluteus maximus. Overall, the use of applied loads appears to promote poorer musculoskeletal alignment in terms of peak knee valgus angle. 3.

  15. Effect of sex and fatigue on muscle stiffness and musculoarticular stiffness of the knee joint in a young active population.

    Science.gov (United States)

    Wang, Dan; De Vito, Giuseppe; Ditroilo, Massimiliano; Delahunt, Eamonn

    2017-08-01

    The purpose of this study was to investigate the influence of sex and fatigue on knee extensor peak torque (PT), muscle stiffness (MS) of the vastus lateralis (VL) and knee joint musculoarticular stiffness (MAS) in young adults. Twenty-two male and 22 female recreational athletes participated. Males were characterised by higher relaxed [pre-: males 364.43 (52.00) N · m -1 , females 270.27 (37.25) N · m -1 ; post-: males 446.75 (83.27) N · m -1 , females 307.39 (38.58) N · m -1 ] and contracted [pre-: males 495.07 (71.04) N · m -1 , females 332.34 (85.42) N · m -1 ; post-: males 546.37 (90.74) N · m -1 , females 349.21 (85.55) N · m -1 ] MS of the VL, and knee joint MAS [pre-: males 1450.11 (507.98) N · m -1 , females 1027.99 (227.33) N · m -1 ; post-: males 1345.81 (404.90) N · m -1 , females 952.78 (192.38) N · m -1 ] than females pre- and post-fatigue. A similar finding was observed in pre-fatigue normalised knee extensor PT [pre-: males 2.77 (0.42) N · m kg -1 , females 2.41 (0.40) N · m kg -1 , post-: males 2.53 (0.54) N · m kg -1 , females 2.26 (0.44) N · m kg -1 ]. After the fatigue protocol, normalised knee extensor PT and knee joint MAS decreased, whilst relaxed and contracted MS of the VL increased in both sexes. These observed differences may contribute to the higher risk of knee injury in females and following the onset of fatigue.

  16. Ulnar-sided pain due to extensor carpi ulnaris tendon subluxation: a case report

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    Cift Hakan

    2012-11-01

    Full Text Available Abstract Introduction We present the case of a patient with extensor carpi ulnaris tendon subluxation who was first treated for distal radioulnar joint sprain. Case presentation A 25-year-old Caucasian man was seen at our policlinic one month after he had fallen on his outstretched hand. A diagnosis of extensor carpi ulnaris subluxation was made clinically but we also had the magnetic resonance imaging scan of the patient’s wrist which displayed an increased signal on T2-weighted images consistent with inflammation around the extensor carpi ulnaris tendon. The extensor carpi ulnaris tendon was found to be dislocating during supination and relocating during pronation. The sheath was reconstructed using extensor retinaculum due to attenuation of subsheath. Conclusion There was no recurrent dislocation of the extensor carpi ulnaris tendon of the patient at his last follow up 12 months after the operation.

  17. Variations in dynamic knee valgus and gluteus medius onset timing in non-athletic females related to hormonal changes during the menstrual cycle.

    Science.gov (United States)

    Cesar, Guilherme Manna; Pereira, Vanessa Santos; Santiago, Paulo Roberto Pereira; Benze, Benedito Galvão; da Costa, Paula Hentshel Lobo; Amorim, César Ferreira; Serrão, Fabio Viadanna

    2011-08-01

    It has been suggested that activities of daily living could contribute to the occurrence of ACL injury in females. Currently, no studies have focused on the lower extremity behavior of a non-athletic population to compare or understand the lower extremity adeptness towards daily movements that mimic athletic tasks. Our hypothesis was that increased knee valgus angles would occur during the late follicular phase of the menstrual cycle accompanied by different onset timing of the gluteus medius muscle. In a controlled laboratory study, 23 non-athletic collegiate females participated and 15 subjects comprised the final sample for statistical analysis. Subjects performed a single leg drop landing maneuver while 3-D knee kinematics and gluteus medius muscle onset timing were assessed throughout three distinct phases of the menstrual cycle, confirmed by blood hormone analysis. In general, knee valgus angles were significantly less in the luteal phase compared to both follicular phases (pgluteus medius onset timing (p=0.936). As a decreased knee joint valgus angle was observed during the luteal phase, it was hypothesized that the hormone progesterone could significantly influence knee kinematics during a dynamic task. However, such influence was not observed for gluteus medius EMG onset timing as a significant correlation between gluteus medius onset timing and knee valgus angle could not be determined. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. Internal derangement of the knee after ipsilateral femoral shaft fracture: MR imaging findings

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    Blacksin, M.F.; Zurlo, J.V. [Department of Radiology, University of Medicine and Dentistry of New Jersey, Newark, NJ (United States); Levy, A.S. [Department of Orthopedic Surgery, University of Medicine and Dentistry of New Jersey, University Hospital, Newark, NJ 07103-2426 (United States)

    1998-08-01

    Objective. This study uses magnetic resonance (MR) imaging to delineate the types and frequencies of injuries seen in the knee after ipsilateral femoral shaft fracture. We also compare the results of the orthopedic knee examination with the MR findings. Design and patients. MR imaging of the ipsilateral knee was performed on 34 patients with closed femoral shaft fractures. Indications for knee MR imaging included knee pain at the time of fracture, soft tissue swelling or an effusion of the knee, or a positive knee examination under anesthesia. The patients had a mean age of 27 years and all were stabilized with intramedullary nails. Imaging was performed a mean time of 2.5 days after surgery. All patients had knee examinations done under anesthesia, and the MR results were compiled and compared with the clinical examinations. Results. Ninety-seven percent of patients demonstrated knee effusions. Twenty-seven percent of patients demonstrated meniscal tears, with the posterior horn of the medial meniscus most frequently torn. The medial collateral ligament was the most frequent site of ligamentous injury (38%) followed by the posterior cruciate ligament (21%). Fifty percent of patients had injuries of the extensor mechanism. Bone bruises were noted in 32% of patients. Articular cartilage injuries were confined to the patella in four cases. One occult tibial plateau fracture and one meniscocapsular separation were seen. Conclusions. There is a common incidence of both ligamentous and meniscal injury to the knee after ipsilateral femoral shaft fracture. MR imaging can be useful in assessing the extent of injury, and may reveal findings unsuspected after clinical examination of the knee. (orig.) With 4 figs., 2 tabs., 13 refs.

  19. Internal derangement of the knee after ipsilateral femoral shaft fracture: MR imaging findings

    International Nuclear Information System (INIS)

    Blacksin, M.F.; Zurlo, J.V.; Levy, A.S.

    1998-01-01

    Objective. This study uses magnetic resonance (MR) imaging to delineate the types and frequencies of injuries seen in the knee after ipsilateral femoral shaft fracture. We also compare the results of the orthopedic knee examination with the MR findings. Design and patients. MR imaging of the ipsilateral knee was performed on 34 patients with closed femoral shaft fractures. Indications for knee MR imaging included knee pain at the time of fracture, soft tissue swelling or an effusion of the knee, or a positive knee examination under anesthesia. The patients had a mean age of 27 years and all were stabilized with intramedullary nails. Imaging was performed a mean time of 2.5 days after surgery. All patients had knee examinations done under anesthesia, and the MR results were compiled and compared with the clinical examinations. Results. Ninety-seven percent of patients demonstrated knee effusions. Twenty-seven percent of patients demonstrated meniscal tears, with the posterior horn of the medial meniscus most frequently torn. The medial collateral ligament was the most frequent site of ligamentous injury (38%) followed by the posterior cruciate ligament (21%). Fifty percent of patients had injuries of the extensor mechanism. Bone bruises were noted in 32% of patients. Articular cartilage injuries were confined to the patella in four cases. One occult tibial plateau fracture and one meniscocapsular separation were seen. Conclusions. There is a common incidence of both ligamentous and meniscal injury to the knee after ipsilateral femoral shaft fracture. MR imaging can be useful in assessing the extent of injury, and may reveal findings unsuspected after clinical examination of the knee. (orig.)

  20. Prevalence of Jumper's knee among nonelite athletes from different sports: a cross-sectional survey.

    Science.gov (United States)

    Zwerver, Johannes; Bredeweg, Steven W; van den Akker-Scheek, Inge

    2011-09-01

    The prevalence of jumper's knee among nonelite athletes from different sports is unknown. This study was undertaken to determine the prevalence of jumper's knee in nonelite athletes from different sports and to determine potential risk factors for jumper's knee. Cohort study (prevalence); Level of evidence, 2. The authors interviewed 891 male and female nonelite athletes from 7 popular sports in The Netherlands: basketball, volleyball, handball, korfball, soccer, field hockey, and track and field. Using a specially developed questionnaire, information was obtained about individual characteristics (age, height, and weight), training background, previous and actual knee problems, and the VISA-P (Victorian Institute of Sport Assessment-Patella) score. The overall prevalence of current jumper's knee was 8.5% (78 of 891 athletes), showing a significant difference between sports with different loading characteristics. Prevalence was highest among volleyball players (14.4%) and lowest among soccer players (2.5%); it was significantly higher among male athletes (51 of 502 [10.2%]) than female athletes (25 of 389 [6.4%]) (χ(2) = 3.91, P = .048). The mean duration of symptoms was 18.9 months (standard deviation [SD], 21.6; median value, 12.0; range, 2.0-59.8). The mean VISA-P score of the athletes with jumper's knee was 71.4 (SD, 13.8). Athletes with jumper's knee were significantly younger, taller, and heavier than those without jumper's knee. Prevalence of jumper's knee is high among nonelite athletes and varies between 14.4% and 2.5% for different sports. Jumper's knee is almost twice as common among male nonelite athletes compared with female athletes. Different sport-specific loading characteristics of the knee extensor apparatus, a younger age, a taller body stature, and higher body weight seem to be risk factors associated with patellar tendinopathy.

  1. Validity and inter-rater reliability of medio-lateral knee motion observed during a single-limb mini squat

    Directory of Open Access Journals (Sweden)

    Simic Milena

    2010-11-01

    Full Text Available Abstract Background Muscle function may influence the risk of knee injury and outcomes following injury. Clinical tests, such as a single-limb mini squat, resemble conditions of daily life and are easy to administer. Fewer squats per 30 seconds indicate poorer function. However, the quality of movement, such as the medio-lateral knee motion may also be important. The aim was to validate an observational clinical test of assessing the medio-lateral knee motion, using a three-dimensional (3-D motion analysis system. In addition, the inter-rater reliability was evaluated. Methods Twenty-five (17 women non-injured participants (mean age 25.6 years, range 18-37 were included. Visual analysis of the medio-lateral knee motion, scored as knee-over-foot or knee-medial-to-foot by two raters, and 3-D kinematic data were collected simultaneously during a single-limb mini squat. Frontal plane 2-D peak tibial, thigh, and knee varus-valgus angles, and 3-D peak hip internal-external rotation, and knee varus-valgus angles were calculated. Results Ten subjects were scored as having a knee-medial-to-foot position and 15 subjects a knee-over-foot position assessed by visual inspection. In 2-D, the peak tibial angle (mean 89.0 (SE 0.7 vs mean 86.3 (SE 0.4 degrees, p = 0.001 and peak thigh angle (mean 77.4 (SE 1.0 vs mean 81.2 (SE 0.5 degrees, p = 0.001 with respect to the horizontal, indicated that the knee was more medially placed than the ankle and thigh, respectively. Thus, the knee was in more valgus (mean 11.6 (SE 1.5 vs 5.0 (SE 0.8 degrees, p 0.90 and 96 between raters. Conclusions Medio-lateral motion of the knee can reliably be assessed during a single-leg mini-squat. The test is valid in 2-D, while the actual movement, in 3-D, is mainly exhibited as increased internal hip rotation. The single-limb mini squat is feasible and easy to administer in the clinical setting and in research to address lower extremity movement quality.

  2. Application of Computational Lower Extremity Model to Investigate Different Muscle Activities and Joint Force Patterns in Knee Osteoarthritis Patients during Walking

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    Kyung Wook Nha

    2013-01-01

    Full Text Available Many experimental and computational studies have reported that osteoarthritis in the knee joint affects knee biomechanics, including joint kinematics, joint contact forces, and muscle activities, due to functional restriction and disability. In this study, differences in muscle activities and joint force patterns between knee osteoarthritis (OA patients and normal subjects during walking were investigated using the inverse dynamic analysis with a lower extremity musculoskeletal model. Extensor/flexor muscle activations and torque ratios and the joint contact forces were compared between the OA and normal groups. The OA patients had higher extensor muscle forces and lateral component of the knee joint force than normal subjects as well as force and torque ratios of extensor and flexor muscles, while the other parameters had little differences. The results explained that OA patients increased the level of antagonistic cocontraction and the adduction moment on the knee joint. The presented findings and technologies provide insight into biomechanical changes in OA patients and can also be used to evaluate the postoperative functional outcomes of the OA treatments.

  3. A lower extremity strength-based profile of NCAA Division I women's basketball and gymnastics athletes: implications for knee joint injury risk assessment.

    Science.gov (United States)

    Thompson, Brennan J; Cazier, Curtis S; Bressel, Eadric; Dolny, Dennis G

    2018-08-01

    This study aimed to provide a comprehensive strength-based physiological profile of women's NCAA Division I basketball and gymnastic athletes; and to make sport-specific comparisons for various strength characteristics of the knee flexor and extensor muscles. A focus on antagonist muscle balance (hamstrings-to-quadriceps ratios, H:Q) was used to elucidate vulnerabilities in these at-risk female athletes. Fourteen NCAA Division I women's basketball and 13 gymnastics athletes performed strength testing of the knee extensors and flexors. Outcome measures included absolute and relative (body mass normalised) peak torque (PT), rate of torque development at 50, 100, 200 ms (RTD50 etc.) and H:Q ratios of all variables. The basketball athletes had greater absolute strength for all variables except for isokinetic PT at 240°s -1 and isometric RTD50 for the knee extensors. Gymnasts showed ~20% weaker body mass relative concentric PT for the knee flexors at 60 and 120°·s -1 , and decreased conventional H:Q ratios at 60 and 240°·s -1 (~15%). These findings suggest that collegiate level gymnastics athletes may be prone to increased ACL injury risk due to deficient knee flexor strength and H:Q strength imbalance. Coaches may use these findings when implementing injury prevention screening and/or for individualised strength training programming centered around an athletes strength-related deficits.

  4. [Extensor digitorum longus transfer in flexible overlapping fifth toe deformity].

    Science.gov (United States)

    Fuhrmann, R A; Pillukat, T

    2014-02-01

    Pain relief through realignment of the fifth toe by dorsomedial capsular release at the fifth metatarsophalaneal joint and transfer of the extensor digitorum longus tendon to the aponeurosis of the abductor digiti quinti muscle. Flexible overlapping fifth toe deformity. Fixed deformity. Angular toe deformity distal to the metatarsophalangeal joint (e.g. delta phalanx). Lateral drift of all lesser toes. Dorsolateral approach to the fifth metatarsophalangeal joint. Release of the dorsomedial capsule. Tenotomy of the fifth extensor digitorum longus tendon at the dorsum of the foot. Transfer of the distally based tendon around the proximal phalanx to the aponeurosis of the abductor digiti quinti muscle. Correction of the deformity by tensioning the tendon graft appropriately. Ambulation with full weightbearing in a postoperative shoe. Toe alignment dressing for 6 weeks. A total of 48 patients (56 feet; average age 37 years) with a flexible overlapping fifth toe deformity were followed up after soft tissue release and transfer of the extensor digitorum longus tendon; 40 patients (48 feet) were re-evaluated clinically after 11.4 months (range 9-26 months). Postoperative complications were sensory disturbance at the lateral side of the fifth toe (n = 5), superficial wound slough (n = 3). Follow-up results included broad and hypertrophic scars at the fifth metatarsophalangeal joint (n = 16), physiological alignment of the fifth toe in 37 feet (77.1%), overcorrection (interdigital space 4/5 > 3 mm) in 4 feet (8.3%), undercorrection in 7 feet (14.6%). In 4 feet the undercorrection could be attributed to a Tailor's bunion deformity, which was not treated appropriately.

  5. Hyperparathyroidism-related extensor tenosynovitis at the wrist: a general review of the literature.

    Science.gov (United States)

    Ichihara, Satoshi; Hidalgo-Diaz, Juan Jose; Prunières, Guillaume; Facca, Sybille; Bodin, Frédéric; Boucher, Stéphanie; Liverneaux, Philippe

    2015-07-01

    Extensor tenosynovitis often occurs accompanying with rheumatoid arthritis, gout, trauma, mycobacterium and dialysis-related amyloidosis. However, there is no recognition of extensor tenosynovitis accompanying with hyperparathyroidism. The purpose of this general review was to describe the clinical condition and to report the results of surgical intervention in the extensor tenosynovitis at the wrist related to hyperparathyroidism. Hyperparathyroidism is thought to be a rare disease in adult. Although renal symptoms are the commonest symptom, musculoskeletal complaints also occur in hyperparathyroidism. From our general review, hyperparathyroidism deserves consideration in the differential diagnosis of extensor tenosynovitis at the wrist.

  6. Neck extensor muscle weakness (Dropped head syndrome) following radiotherapy

    International Nuclear Information System (INIS)

    Bhatia, S.; Miller, R.C.; Lachance, D.L.

    2006-01-01

    Background. Dropped head syndrome is an unusual condition in which the head cannot be held upright in its normal anatomic position secondary to pronounced, isolated, neck extensor muscle weakness. Case report. A case of dropped head syndrome in a female with a history of radiotherapy for Hodgkin's lymphoma and a clinical history consistent with multiple sclerosis is presented, and potential etiologies are discussed. Conclusions. Muscular atrophy and lower motor neuron injury secondary to isolated anterior horn cell injury from radiotherapy emerge as the most likely etiology. (author)

  7. Polypropylene mesh augmentation for complete quadriceps rupture after total knee arthroplasty.

    Science.gov (United States)

    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.

  8. Elevated corticospinal excitability in patellar tendinopathy compared with other anterior knee pain or no pain.

    Science.gov (United States)

    Rio, E; Kidgell, D; Moseley, G L; Cook, J

    2016-09-01

    Anterior knee pain (AKP) is a frequent clinical presentation in jumping athletes and may be aggravated by sustained sitting, stair use, and loading of the quadriceps. Corticospinal activation of the quadriceps in athletes with AKP has not yet been investigated, but is important in guiding efficacious treatment. This cross-sectional study assessed corticospinal excitability (CSE) of the quadriceps in jumping athletes using transcranial magnetic stimulation (TMS). Groups consisted of Control (no knee pain); patellar tendinopathy (PT) [localized inferior pole pain on single-leg decline squat (SLDS)]; and other AKP (nonlocalized pain around the patella). SLDS (numerical score of pain 0-10), Victorian Institute of Sport Assessment Patellar tendon (VISA-P), maximal voluntary isometric contraction (MVIC), active motor threshold (AMT), CSE, and Mmax were tested. Twenty nine athletes participated; control n = 8, PT n = 11, AKP n = 10. There were no group differences in age (P = 0.23), body mass index (P = 0.16), MVIC (P = 0.38) or weekly activity (P = 0.22). PT had elevated CSE compared with controls and other AKP (P knee pain may direct better treatment approaches. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. UCI knee replacement.

    Science.gov (United States)

    Evanski, P M; Waugh, T R; Orofino, C F; Anzel, S H

    1976-10-01

    Between March 9, 1972 and December 31, 1973, a total of 103 UCI knee replacements were performed. Follow-up data are available on 83 knees with an average follow-up of 33 months. Patient evaluation of the end results indicates that 78.3 per cent were better, 9.6 per cent unchanged, and 12.1 per cent worse. Patient evaluation of their own knee function averaged 55 per cent preoperatively and 79 per cent postoperatively. Patients were also evaluated on a 100 point Modified Larson Analysis Form. The average preoperative score was 46, and the average postoperative score was 70. There were six (5.8%) biological complications in the 103 knee replacement. Biological complications included infections, wound healing problems and unexplained pain. Mechanical complications were seen in 18 (17.4%) knees, and included knee instability, tibial component loosening or deformation, and patellar problems. Additional surgery was required in 18 (17.4%) knees. Failure of the procedure eventually requiring removal of the prosthesis and fusion or amputation occurred in 4 (3.9%) knees. The intermediate-term results of UCI knee replacement have been clinically satisfactory. We currently recommend consideration of this procedure for patients with disabling arthritis of the knee.

  10. Brief Report: Loss of Muscle Strength Prior to Knee Replacement: A Question of Anatomic Cross-Sectional Area or Specific Strength?

    Science.gov (United States)

    Culvenor, Adam G; Hamler, Felix C; Kemnitz, Jana; Wirth, Wolfgang; Eckstein, Felix

    2018-02-01

    To determine whether loss in thigh muscle strength prior to knee replacement is caused by reductions of muscle strength in the anatomic cross-sectional area or by reductions of specific strength. All 100 of the participants in the Osteoarthritis Initiative who underwent knee replacement and whose medical records included data on thigh isometric muscle strength and magnetic resonance imaging (MRI) (58 women, and 42 men, mean ± SD age 65 ± 8 years, mean ± SD body mass index [BMI] 29 ± 5 kg/m 2 ) were matched with a control (no knee replacement) for age, sex, height, BMI, and radiographic severity. Thigh muscle anatomic cross-sectional area was determined by MRI at the research visit before knee replacement (time 0) and 2 years before time 0 (time -2). Specific strength (strength/anatomic cross-sectional area) was calculated, and the measures were compared by conditional logistic regression (i.e., odds ratio [OR] per standard deviation). ORs adjusted for pain (OR adj ) and 95% confidence intervals (95% CIs) were also calculated. Knee replacement cases had significantly smaller extensor (but not flexor) anatomic cross-sectional areas than controls at time 0 (women, OR adj 1.89 [95% CI 1.05-3.90]; men, OR adj 2.22 [95% CI 1.04-4.76]), whereas no significant differences were found at time -2. Women who had knee replacement showed lower levels of extensor specific strength than controls at time 0 (OR 1.59 [95% CI 1.02-2.50]), although this difference was not observed in men and did not maintain significance after adjustment for pain (OR adj 1.22 [95% CI 0.71-2.08]). Female cases lost significantly more extensor specific strength between time -2 and time 0 than controls (OR adj 3.76 [95% CI 1.04-13.60]), whereas no significant differences were noted at time -2, or in men. Prior to knee replacement, a significant reduction in knee extensor strength appears to occur in women through 2 mechanisms: one driven by pain (loss of specific strength) and one independent of pain

  11. Isometric hip muscle strength in posttraumatic below-knee amputees

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    Jandrić Slavica

    2007-01-01

    Full Text Available Background/Aim. Traumas and war injuries, next to chronic occlusive artery disease and diabetes mellitus-derived complications, are the most frequent cause of the lower limbs amputation. They affect mostly younger population that need a higher level of activities as compared with the elderly. Medical rehabilitation is very significant for the muscle performance improvement in this population providing their social reintegration. The aim of this study was to investigate the effect of below-knee amputation on the hip isometric muscle strength and effect of rehabilitation on improvement of hip muscle strength in below-knee amputees, secondary to war wounding. Methods. Forty below-knee amputees (after war wounding, average age 35.6±10.6 years, that were included in primary rehabilitation program with prosthetics, were examined. Objective parameters were used to evaluate therapeutical effects. Isometric muscle strength of hip flexors, extensors, abductors and adductors was measured by dynamometer and expressed in Newton (N at admission, control and discharge for each patient. Average length of the treatment was 51 ± 34.1 days. Results. For isometric hip flexors (t = - 1.99346, p < 0.05, extensors (t = -4.629073, p < 0.001, abductors (t = -4.9408, p < 0.001 and adductors (t = -2.00228, p < 0.05, muscle strength was significantly less on the amputated than on nonamputated side. The highest differences in muscle strength between amputated and nonamputated limbs were noted for hip abductors (26.6% and extensors (23.3%. There was significant improvement of mean values of strength for all examined hip muscles after rehabilitation and prosthetics for both legs in comparison to beginning of the therapy. The hip abductor on the amputated side was for 19.4% weaker after rehabilitation in comparison to the nonamputated limb. Conclusion. Decreases of isometric muscle strength in all examined hip muscles were observed, more in the amputated limb. Rehabilitation

  12. KNEE ISOKINETIC TORQUE IMBALANCE IN FEMALE FUTSAL PLAYERS

    Directory of Open Access Journals (Sweden)

    Ana Carolina de Mello Alves Rodrigues

    Full Text Available ABSTRACT Introduction: The specificity of sports training can lead to muscle specialization with a possible change in the natural hamstring/quadriceps torque ratio (HQ ratio, constituting a risk factor for muscle injury at the joint angles in which muscle imbalance may impair dynamic stability. Objective: The aim was to evaluate the torque distribution of the hamstrings and quadriceps and the HQ ratio throughout the range of motion in order to identify possible muscle imbalances at the knee of female futsal athletes. Methods: Nineteen amateur female futsal athletes had their dominant limb HQ ratio evaluated in a series of five maximum repetitions of flexion/extension of the knee at 180°/second in the total joint range of motion (30° to 80°. The peak flexor and extensor torque and the HQ ratio (% were compared each 5° of knee motion using one-way repeated measures ANOVA and Tukey’s post hoc test (p<0.05 to determine the joint angles that present muscular imbalance. Results: Quadriceps torque was higher than 50° to 60° of knee flexion, while hamstrings torque was higher than 55° to 65°. The HQ ratio presented lower values than 30° to 45° of knee flexion and four athletes presented values lower than 60%, which may represent a risk of injury. However, the HQ ratio calculated by the peak torque showed only one athlete with less than 60%. Conclusion: The HQ ratio analyzed throughout the knee range of motion allowed identifying muscle imbalance at specific joint angles in female futsal players.

  13. The pediatric knee.

    Science.gov (United States)

    Orth, Robert C

    2013-03-01

    Knee pain is a common problem in children and adolescents, and MRI of the knee is the most commonly performed pediatric cross-sectional musculoskeletal imaging exam. The purpose of this pictorial review is to highlight differences between adult and pediatric knee imaging with an emphasis on normal developmental variants, injury and disease patterns unique to children and adolescents, and differences in response and presentation to conditions affecting both adults and children.

  14. Knee kinematics and kinetics in former soccer players with a 16-year-old ACL injury – the effects of twelve weeks of knee-specific training

    Directory of Open Access Journals (Sweden)

    Holmström Eva

    2007-04-01

    Full Text Available Abstract Background Training of neuromuscular control has become increasingly important and plays a major role in rehabilitation of subjects with an injury to the anterior cruciate ligament (ACL. Little is known, however, of the influence of this training on knee stiffness during loading. Increased knee stiffness occurs as a loading strategy of ACL-injured subjects and is associated with increased joint contact forces. Increased or altered joint loads contribute to the development of osteoarthritis. The aim of the study was to determine if knee stiffness, defined by changes in knee kinetics and kinematics of gait, step activity and cross-over hop could be reduced through a knee-specific 12-week training programme. Methods A 3-dimensional motion analysis system (VICON and a force plate (AMTI were used to calculate knee kinetics and kinematics before and after 12 weeks of knee-specific training in 12 males recruited from a cohort with ACL injury 16 years earlier. Twelve uninjured males matched for age, sex, BMI and activity level served as a reference group. Self-reported patient-relevant data were obtained by the KOOS questionnaire. Results There were no significant changes in knee stiffness during gait and step activity after training. For the cross-over hop, increased peak knee flexion during landing (from 44 to 48 degrees, p = 0.031 and increased internal knee extensor moment (1.28 to 1.55 Nm/kg, p = 0.017 were seen after training, indicating reduced knee stiffness. The KOOS sport and recreation score improved from 70 to 77 (p = 0.005 and was significantly correlated with the changes in knee flexion during landing for the cross-over hop (r = 0.6, p = 0.039. Conclusion Knee-specific training improved lower extremity kinetics and kinematics, indicating reduced knee stiffness during demanding hop activity. Self-reported sport and recreational function correlated positively with the biomechanical changes supporting a clinical importance of the

  15. Total knee arthroplasty

    DEFF Research Database (Denmark)

    Schrøder, Henrik M.; Petersen, Michael M.

    2016-01-01

    Total knee arthroplasty (TKA) is a successful treatment of the osteoarthritic knee, which has increased dramatically over the last 30 years. The indication is a painful osteoarthritic knee with relevant radiographic findings and failure of conservative measures like painkillers and exercise...... surgeon seems to positively influence the rate of surgical complications and implant survival. The painful TKA knee should be thoroughly evaluated, but not revised except if a relevant indication can be established. The most frequent indications for revision are: aseptic loosening, instability, infection...

  16. Knee Bracing: What Works?

    Science.gov (United States)

    ... Fitness, Exercise Basics, First Aid and Injury Prevention, Injury Rehabilitation, Prevention and Wellness, Sports SafetyTags: Knee Pain, Pain Management September 1, 2005 Copyright © American ...

  17. The association between antagonist hamstring coactivation and episodes of knee joint shifting and buckling.

    Science.gov (United States)

    Segal, N A; Nevitt, M C; Welborn, R D; Nguyen, U-S D T; Niu, J; Lewis, C E; Felson, D T; Frey-Law, L

    2015-07-01

    Hamstring coactivation during quadriceps activation is necessary to counteract the quadriceps pull on the tibia, but coactivation can be elevated with symptomatic knee osteoarthritis (OA). To guide rehabilitation to attenuate risk for mobility limitations and falls, this study evaluated whether higher antagonistic open kinetic chain hamstring coactivation is associated with knee joint buckling (sudden loss of support) and shifting (a sensation that the knee might give way). At baseline, median hamstring coactivation was assessed during maximal isokinetic knee extensor strength testing and at baseline and 24-month follow-up, knee buckling and shifting was self-reported. Associations between tertiles of co-activation and knee (1) buckling, (2) shifting and (3) either buckling or shifting were assessed using logistic regression, adjusted for age, sex, knee OA and pain. 1826 participants (1089 women) were included. Mean ± SD age was 61.7 ± 7.7 years, BMI was 30.3 ± 5.5 kg/m(2) and 38.2% of knees had OA. There were no consistent statistically significant associations between hamstring coactivation and ipsilateral prevalent or incident buckling or the combination of buckling and shifting. The odds ratios for incident shifting in the highest in comparison with the lowest tertile of coactivation had similar magnitudes in the combined and medial hamstrings, but only reached statistical significance for lateral hamstring coactivation, OR(95%CI) 1.53 (0.99, 2.36). Hamstring coactivation during an open kinetic chain quadriceps exercise was not consistently associated with prevalent or incident self-reported knee buckling or shifting in older adults with or at risk for knee OA. Copyright © 2015. Published by Elsevier Ltd.

  18. Human hip and knee torque accommodations to anterior cruciate ligament dysfunction.

    Science.gov (United States)

    Osternig, L R; Ferber, R; Mercer, J; Davis, H

    2000-09-01

    It has been postulated that the adaptations of lower extremity function exhibited by anterior cruciate ligament (ACL) deficient and post-ACL surgical patients represent early accommodations to the loss of ACL function after injury so that excessive anterior displacement of the tibia is prevented. Prior studies have suggested that compensation patterns in ACL deficient and post-ACL surgical subjects may affect joint moments of the knee as well as the hip. However, the variance in knee and hip forces between ACL deficient, post-surgical ACL and uninjured groups has not been clearly elucidated. The purpose of this study was to assess hip:knee extensor torque ratios relative to anterior tibia shear in pre-surgical-ACL deficient, post-surgical and uninjured subjects. Measurements of hip and knee joint moments and anterior tibia shear were recorded from 45 injured and uninjured subjects (21 men, 24 women) during lower extremity, variable resistance exercise. Anterior tibia shear was computed by decomposing joint moments and reaction forces according to a model derived from cadaver knee dissections and radiography, in combination, to estimate the tibio-femoral compressive and shear forces generated by the patellar tendon at various angles throughout the knee joint range. Three groups of subjects were studied: recently injured ACL deficient pre-surgical subjects who were scheduled for immediate surgery (PRE; n = 15); postsurgical subjects who had undergone ACL reconstructive surgery at least 1 year prior to testing (POST; n = 15); and uninjured controls (CON; n = 15). All PRE and POST subjects had a normal contralateral limb. Tests were conducted under six conditions: 1 and 1.5 Hz cadence and maximal speed at 33% and 50% one repetition maximum resistance. The results revealed that the hip:knee ratios were significantly greater for the post-ACL surgical group than the PRE and CON groups (PACL surgical subjects appear to accommodate to ACL substitution by using hip extensors

  19. ''Dropped-head'' syndrome due to isolated myositis of neck extensor muscles: MRI findings

    International Nuclear Information System (INIS)

    Gaeta, Michele; Mazziotti, Silvio; Blandino, Alfredo; Toscano, Antonio; Rodolico, Carmelo; Mazzeo, Anna

    2006-01-01

    MRI findings of a patient with dropped-head syndrome due to focal myositis of the neck extensor muscles are presented. MRI showed oedematous changes and marked enhancement of the neck extensor muscles. After therapy MRI demonstrated disappearance of the abnormal findings. (orig.)

  20. An anatomic and biomechanic study of the wrist extensor retinaculum septa and tendon compartments.

    Science.gov (United States)

    Iwamoto, Akira; Morris, Randal P; Andersen, Clark; Patterson, Rita M; Viegas, Steven F

    2006-01-01

    The anatomy of the extensor retinaculum of the wrist has been described previously; the purpose of this study was to describe the specific anatomy of the septal attachments on the radius and to investigate the mechanical strength of each septal attachment on the radius and each of the 6 compartments of the extensor retinaculum. Thirty-four wrists from 24 fresh-frozen and 10 embalmed cadavers were used. First, anatomic measurements of the individual extensor retinaculum septums were performed with calipers and a 3-dimensional digitizer. Next each extensor retinaculum septum was excised as a bone-retinaculum-bone autograft and was tested in tension to failure with a materials testing machine. Finally the 6 extensor retinaculum compartments were tested to failure. Septum 1/2 had the largest radial surface area and septum 3/4 had the smallest. Septum 1/2 also was found to have the highest failure strength at 51.3 +/- 15.3 N. In compartment testing, compartments 1 and 2 had the highest overall resistance to failure and compartment 5 had the lowest. Compartment 6, which was thought to be the weakest because of clinically observed subluxation of the extensor carpi ulnaris tendon, had stronger failure data than expected. This study offers detailed analysis of the extensor retinaculum compartments and 3-dimensional anatomy of the septal attachments. Clinically this study lends insight to the strength of bone-retinaculum-bone autografts and the etiology of extensor carpi ulnaris subluxation.

  1. Extensor Tendon Instability Due to Sagittal Band Injury in a Martial Arts Athlete: A Case Report.

    Science.gov (United States)

    Kochevar, Andrew; Rayan, Ghazi

    2017-03-01

    A Taekwondo participant sustained a hand injury from punching an opponent that resulted in painful instability of the ring finger extensor digitorum communis tendon due to sagittal band damage. His symptoms resolved after reconstructive surgery on the sagittal band (SB) with stabilization of the extensor tendon over the metacarpophalangeal joint.

  2. The role of muscle strengthening in exercise therapy for knee osteoarthritis

    DEFF Research Database (Denmark)

    Bartholdy, Cecilie; Juhl, Carsten; Christensen, Robin

    2017-01-01

    OBJECTIVES: To analyze if exercise interventions for patients with knee osteoarthritis (OA) following the American College of Sports Medicine (ACSM) definition of muscle strength training differs from other types of exercise, and to analyze associations between changes in muscle strength, pain......, and disability. METHODS: A systematic search in 5 electronic databases was performed to identify randomized controlled trials comparing exercise interventions with no intervention in knee OA, and reporting changes in muscle strength and in pain or disability assessed as standardized mean differences (SMD......) with 95% confidence intervals (95% CI). Interventions were categorized as ACSM interventions or not-ACSM interventions and compared using stratified random effects meta-analysis models. Associations between knee extensor strength gain and changes in pain/disability were assessed using meta...

  3. Mechanics of the knee. A study of joint and muscle load with clinical applications.

    Science.gov (United States)

    Nisell, R

    1985-01-01

    The load moment of force about the knee joint during machine milking and when lifting a 12.8 kg box was quantified using a computerized static sagittal plane body model. Surface electromyography of quadriceps and hamstrings muscles was normalized and expressed as a percentage of an isometric maximum voluntary test contraction. Working with straight knees and the trunk flexed forwards induced extending knee load moments of maximum 55 Nm. Lifting the box with flexed knees gave flexing moments of 50 Nm at the beginning of the lift, irrespective of whether the burden was between or in front of the feet. During machine milking, a level difference between operator and cow of 0.70 m - 1.0 m significantly lowered the knee extending moments. To quantify the force magnitudes acting in the tibio-femoral and patello-femoral joints, a local biomechanical model of the knee was developed using a combination of cadaver knee dissections and lateral knee radiographs of healthy subjects. The moment arm of the knee extensor was significantly shorter for women than for men, which resulted in higher knee joint forces in women if the same moment was produced. A diagram for quantifying patellar forces was worked out. The force magnitudes given by the knee joint biomechanical model correlated well with experimentally forces measured by others. During the parallel squat in powerlifting, the maximum flexing knee load moment was estimated to 335-550 Nm when carrying a 382.5 kg burden and the in vivo force of a complete quadriceps tendon-muscle rupture to between 10,900 and 18,300 N. During isokinetic knee extension, the tibio-femoral compressive force reached peak magnitudes of 9 times body weight and the anteroposterior shear force was close to 1 body weight at knee angles straighter than 60 degrees, indicating that high forces stress the anterior cruciate ligament. A proximal resistance pad position decreased the shear force considerably, and this position is recommended in early

  4. Reliability of maximal isometric knee strength testing with modified hand-held dynamometry in patients awaiting total knee arthroplasty: useful in research and individual patient settings? A reliability study.

    Science.gov (United States)

    Koblbauer, Ian F H; Lambrecht, Yannick; van der Hulst, Micheline L M; Neeter, Camille; Engelbert, Raoul H H; Poolman, Rudolf W; Scholtes, Vanessa A

    2011-10-31

    Patients undergoing total knee arthroplasty (TKA) often experience strength deficits both pre- and post-operatively. As these deficits may have a direct impact on functional recovery, strength assessment should be performed in this patient population. For these assessments, reliable measurements should be used. This study aimed to determine the inter- and intrarater reliability of hand-held dynamometry (HHD) in measuring isometric knee strength in patients awaiting TKA. To determine interrater reliability, 32 patients (81.3% female) were assessed by two examiners. Patients were assessed consecutively by both examiners on the same individual test dates. To determine intrarater reliability, a subgroup (n = 13) was again assessed by the examiners within four weeks of the initial testing procedure. Maximal isometric knee flexor and extensor strength were tested using a modified Citec hand-held dynamometer. Both the affected and unaffected knee were tested. Reliability was assessed using the Intraclass Correlation Coefficient (ICC). In addition, the Standard Error of Measurement (SEM) and the Smallest Detectable Difference (SDD) were used to determine reliability. In both the affected and unaffected knee, the inter- and intrarater reliability were good for knee flexors (ICC range 0.76-0.94) and excellent for knee extensors (ICC range 0.92-0.97). However, measurement error was high, displaying SDD ranges between 21.7% and 36.2% for interrater reliability and between 19.0% and 57.5% for intrarater reliability. Overall, measurement error was higher for the knee flexors than for the knee extensors. Modified HHD appears to be a reliable strength measure, producing good to excellent ICC values for both inter- and intrarater reliability in a group of TKA patients. High SEM and SDD values, however, indicate high measurement error for individual measures. This study demonstrates that a modified HHD is appropriate to evaluate knee strength changes in TKA patient groups. However

  5. [Knee disarticulation and through-knee amputation].

    Science.gov (United States)

    Baumgartner, R

    2011-10-01

    A knee disarticulation or a through-knee stump is superior compared to a transfemoral stump. The thigh muscles are all preserved, and the muscle balance remains undisturbed. The range of motion of the hip joint is not limited. The bulbous shape of the stump allows full weight bearing at the stump end and can easily be fitted with a prosthesis. An amputee with a bilateral knee disarticulation is able to walk "barefoot". A more distal amputation level, e.g., an ultra-short transtibial amputation, is not possible. Important alternative to transfemoral amputations. Possible for any etiology except for Buerger-Winiwarter's disease. New indications are infected and loosened total knee replacements. Preservation of the knee joint is possible. Knee disarticulation is a very atraumatic procedure, compared to transfemoral amputations. Neither bones nor muscles have to be severed, just skin, ligaments, vessels, and nerves. Even the meniscal cartilages may be left in place to act as axial shock absorbers. The cartilage of the femur is not resected, but only bevelled in case of osteoarthritis. There are no tendon attachments or myoplastic procedures necessary. The patella remains in place and is held in position only by the retinacula. Skin closure must be performed without the slightest tension, and if possible not in the weight-bearing area. Transcondylar amputations across the femoral condyles only are indicated when there are not sufficient soft tissues for wound closure of a knee disarticulation. Alternatives as the techniques of Gritti, Klaes, and Eigler, the shortening of the femur and the Sauerbruch's rotation plasty [14] are presented and discussed. The risk of decubital ulcers is rather high. Correct bandaging of the stump is, therefore, particularly important. Prosthetic fitting is possible 3-6 weeks after surgery. The type of prosthesis depends on the amputee's activity level. The superior performance of amputees with knee disarticulations in sports prove the

  6. Spontaneous Extensor Tendon Rupture in the Rheumatoid Wrist: Risk Factors and Preventive Role of Extended Tenosynovectomy.

    Science.gov (United States)

    Hsueh, Jung-Hua; Liu, Wen-Chung; Yang, Kuo-Chung; Hsu, Kuei-Chang; Lin, Cheng-Ta; Chen, Lee-Wei

    2016-03-01

    Spontaneous extensor tendon rupture is often seen in rheumatoid arthritis (RA) patients, but the risk factors are not clearly defined. We therefore collected the data of RA patients with previous extensor tendon rupture and those with tenosynovitis and analyzed the relationship between extended tenosynovectomy and spontaneous extensor tendon rupture. We retrospectively reviewed 17 spontaneous extensor tendon rupture episodes in 15 RA patients and 14 tenosynovitis episodes that required tenosynovectomy in 12 RA patients from 1997 to 2013. Correlations between the incidence of tendon rupture, X-ray findings, and clinical findings in the affected wrists before tendon rupture were analyzed statistically using the test for proportion. The following parameters were significantly correlated with spontaneous extensor tendon rupture: disease duration longer than 8 years, persistent tenosynovitis longer than 1 year duration, and Larsen grade greater than 4 (P = 0.02, 0.03, and 0.01, respectively). Dislocation of the distal end of the ulna, carpal collapse, and the scallop sign on X-ray contributed to a higher spontaneous extensor tendon rupture rate among RA patients (P = 0.01, 0.05, and 0.03, respectively). Extended tenosynovectomy was performed on 14 wrists in 12 RA patients with persistent tenosynovitis longer than 6 months, and Larsen grade did not deteriorate in this group compared with those who did not undergo the surgery. No spontaneous extensor tendon rupture occurred following the surgery. Risk factors of spontaneous extensor tendon rupture included disease duration longer than 8 years, persistent tenosynovitis longer than 1 year, and wrist Larsen grade greater than 4. Dislocation of the distal end of the ulna, carpal collapse, and the scallop sign on X-ray indicated a higher probability of extensor tendon rupture. Rheumatologists should consult with hand surgeons promptly to preserve hand function before tendon rupture. Prophylactic extended tenosynovectomy

  7. Accuracy of High-Resolution Ultrasonography in the Detection of Extensor Tendon Lacerations.

    Science.gov (United States)

    Dezfuli, Bobby; Taljanovic, Mihra S; Melville, David M; Krupinski, Elizabeth A; Sheppard, Joseph E

    2016-02-01

    Lacerations to the extensor mechanism are usually diagnosed clinically. Ultrasound (US) has been a growing diagnostic tool for tendon injuries since the 1990s. To date, there has been no publication establishing the accuracy and reliability of US in the evaluation of extensor mechanism lacerations in the hand. The purpose of this study is to determine the accuracy of US to detect extensor tendon injuries in the hand. Sixteen fingers and 4 thumbs in 4 fresh-frozen and thawed cadaveric hands were used. Sixty-eight 0.5-cm transverse skin lacerations were created. Twenty-seven extensor tendons were sharply transected. The remaining skin lacerations were used as sham dissection controls. One US technologist and one fellowship-trained musculoskeletal radiologist performed real-time dynamic US studies in and out of water bath. A second fellowship trained musculoskeletal radiologist subsequently reviewed the static US images. Dynamic and static US interpretation accuracy was assessed using dissection as "truth." All 27 extensor tendon lacerations and controls were identified correctly with dynamic imaging as either injury models that had a transected extensor tendon or sham controls with intact extensor tendons (sensitivity = 100%, specificity = 100%, positive predictive value = 1.0; all significantly greater than chance). Static imaging had a sensitivity of 85%, specificity of 89%, and accuracy of 88% (all significantly greater than chance). The results of the dynamic real time versus static US imaging were clearly different but did not reach statistical significance. Diagnostic US is a very accurate noninvasive study that can identify extensor mechanism injuries. Clinically suspected cases of acute extensor tendon injury scanned by high-frequency US can aid and/or confirm the diagnosis, with dynamic imaging providing added value compared to static. Ultrasonography, to aid in the diagnosis of extensor mechanism lacerations, can be successfully used in a reliable and

  8. Knee arthroscopy - series (image)

    Science.gov (United States)

    ... between the femur and the tibia in the knee joint. The anterior cruciate ligament, the posterior cruciate ligament, and the ... Several small punctures are made into the knee joint while the patient ... and pain-free (regional anesthesia or spinal anesthesia).

  9. Knee injuries in football

    African Journals Online (AJOL)

    Collateral ligament. Fortunately the majority of knee injuries are strains involving the ligaments. The medial collateral ligament (MCL), which resists valgus and internal rotation, is susceptible to contact and non-contact loads. The MCL is the most commonly injured ligament in the knee.13 In an audit of soccer injuries in ...

  10. Anterior referencing of tibial slope in total knee arthroplasty considerably influences knee kinematics: a musculoskeletal simulation study.

    Science.gov (United States)

    Marra, Marco A; Strzelczak, Marta; Heesterbeek, Petra J C; van de Groes, Sebastiaan A W; Janssen, Dennis W; Koopman, Bart F J M; Wymenga, Ate B; Verdonschot, Nico J J

    2017-05-12

    In total knee arthroplasty (TKA), the posterior tibial slope is not always reconstructed correctly, and the knee ligaments may become too tight in flexion. To release a tight flexion gap, surgeons can increase the posterior tibial slope using two surgical resection techniques: the anterior tibial cortex (ACR) or the centre of tibial plateau (CPR) referencing. It is not known how this choice affects the knee laxity and function during activities of daily living. The aim of this study was to investigate the effect of tibial slope on knee laxity, kinematics and forces during a squatting activity using computer simulation techniques. We hypothesised that the effects depend on the referencing technique utilised. A validated musculoskeletal model of TKA was used. Knee laxity tests were simulated in flexion and extension. Then, a squat motion was simulated to calculate: movement of the tibiofemoral joint (TFJ) contact points and patello-femoral joint (PFJ) contact force. All analyses were repeated with more anterior (-3°), neutral (0°), and more posterior tibial slope (+3°, +6°, +9°), and with two referencing techniques (ACR, CPR). Knee laxities increased dramatically with more posterior slope with the ACR technique (up to 400%), both in flexion and in extension. The CPR technique, instead, had much smaller effects (up to 42% variations). During squatting, more slope with the ACR technique resulted in larger movements of the TFJ contact point. The PFJ contact force decreased considerably with more slope with the CPR technique (12% body weight reduction every 3° more posterior slope), thanks to the preservation of the patellar height and quadriceps-femur load sharing. ACR technique alters considerably the knee laxity, both in flexion and extensions, and surgeons should be cautious about its use. More slope with CPR technique induces more favourable TFJ kinematics and loading of the knee extensor apparatus and does not substantially alter knee laxity. Preferably, the

  11. Assessment of net knee moment-angle characteristics by instrumented hand-held dynamometry in children with spastic cerebral palsy and typically developing children.

    Science.gov (United States)

    Haberfehlner, Helga; Maas, Huub; Harlaar, Jaap; Newsum, Irene E; Becher, Jules G; Buizer, Annemieke I; Jaspers, Richard T

    2015-08-15

    The limited range of motion during walking in children with spastic cerebral palsy (SCP) may be the result of altered mechanical characteristics of muscles and connective tissues around the knee joint. Measurement of static net knee moment-angle relation will provide insights into these alterations, for which instrumented hand-held dynamometry may be applied. The aims of this study were: (1) to test the measurement error of the estimated net knee moment-angle characteristics, (2) to determine the correlation between knee extension angle measurement at a standardized knee moment and popliteal angle from common physical examination and (3) to compare net knee moment-angle characteristics in SCP versus typically developing children. With the child lying in sideward position, the knee was extended by moving the lower leg by a hand-held force transducer on a low friction cart. Force data were collected for a range of knee angles. Data were excluded when activity (EMG) levels of knee extensor and flexor muscles exceeded the EMG level during rest by more than two standard deviations. The net knee flexion moments were calculated from recorded force data and measured moment arm. Reliability for knee angles corresponding with 0.5, 1, 2, 3, and 4 Nm knee net flexion moments was assessed by standard error of measurements (SEM) and smallest detectable difference (SDD). For between day comparison, SEMs were about 5° and SDDs were below 14° for knee angles at 1-4 Nm net knee flexion moments. In SCP children, the knee angle measured at 4 Nm knee flexion moment was not related to the popliteal angle (r = 0.52). The slope at 4 Nm of the knee moment-angle curve in SCP children was significantly higher than that in typically developing children. The presented knee hand-held dynamometry allows assessment of net knee flexion moment-knee angle characteristics in typically developing and SCP children and can be used to identify clinically relevant changes as a result of treatment

  12. Musculoskeletal MR: knee

    International Nuclear Information System (INIS)

    Staebler, A.; Glaser, C.; Reiser, M.

    2000-01-01

    Magnetic resonance imaging is the most sensitive, specific, and accurate noninvasive method for diagnosing internal derangement of the knee. During the past 15 years knowledge of pathologic conditions of the knee had evolved significantly. Beyond the basic principles of imaging knee injuries great impact was made on the understanding of indirect or collateral findings, even in rare diseases. In this article the spectrum of disorders of the knee are reviewed and an overview of the current literature is given. This includes considerations about how to achieve a high-standard MR imaging study of the knee, and principles of imaging anterior cruciate ligament and meniscal tears. A focus is put on distinct diseases including intra-articular and intraosseous ganglion cysts, iliotibial band friction syndrome, transient osteoporosis, osteonecrosis, osteochondritis dissecans, and imaging of the articular cartilage. (orig.)

  13. Does knee awareness differ between different knee arthroplasty prostheses?

    DEFF Research Database (Denmark)

    Thomsen, Morten G; Latifi, Roshan; Kallemose, Thomas

    2016-01-01

    BACKGROUND: Low knee awareness after Total Knee Arthroplasty (TKA) has become the ultimate goal in trying to achieve a natural feeling knee that meet patient expectations. To accommodate this manufacturers of TKAs have developed new prosthetic designs that potentially could give patients a more n...... a standard CR TKA, indicating that the use of this newer prosthetic design facilitate less knee awareness and better function after TKA.......BACKGROUND: Low knee awareness after Total Knee Arthroplasty (TKA) has become the ultimate goal in trying to achieve a natural feeling knee that meet patient expectations. To accommodate this manufacturers of TKAs have developed new prosthetic designs that potentially could give patients a more...

  14. Muscle Power Is an Independent Determinant of Pain and Quality of Life in Knee Osteoarthritis.

    Science.gov (United States)

    Reid, Kieran F; Price, Lori Lyn; Harvey, William F; Driban, Jeffrey B; Hau, Cynthia; Fielding, Roger A; Wang, Chenchen

    2015-12-01

    This study examined the relationships between leg muscle strength, power, and perceived disease severity in subjects with knee osteoarthritis (OA) in order to determine whether dynamic leg extensor muscle power would be associated with pain and quality of life in knee OA. Baseline data on 190 subjects with knee OA (mean ± SD age 60.2 ± 10.4 years, body mass index 32.7 ± 7.2 kg/m(2) ) were obtained from a randomized controlled trial. Knee pain was measured using the Western Ontario and McMaster Universities Osteoarthritis Index, and health-related quality of life was assessed using the Short Form 36 (SF-36). One-repetition maximum (1RM) strength was assessed using the bilateral leg press, and peak muscle power was measured during 5 maximum voluntary velocity repetitions at 40% and 70% of 1RM. In univariate analysis, greater muscle power was significantly associated with pain (r = -0.17, P determinant of pain or quality of life (P ≥ 0.06). Muscle power is an independent determinant of pain and quality of life in knee OA. Compared to strength, muscle power may be a more clinically important measure of muscle function within this population. New trials to systematically examine the impact of muscle power training interventions on disease severity in knee OA are particularly warranted. © 2015, American College of Rheumatology.

  15. A pneumatically powered knee-ankle-foot orthosis (KAFO) with myoelectric activation and inhibition

    Science.gov (United States)

    Sawicki, Gregory S; Ferris, Daniel P

    2009-01-01

    Background The goal of this study was to test the mechanical performance of a prototype knee-ankle-foot orthosis (KAFO) powered by artificial pneumatic muscles during human walking. We had previously built a powered ankle-foot orthosis (AFO) and used it effectively in studies on human motor adaptation, locomotion energetics, and gait rehabilitation. Extending the previous AFO to a KAFO presented additional challenges related to the force-length properties of the artificial pneumatic muscles and the presence of multiple antagonistic artificial pneumatic muscle pairs. Methods Three healthy males were fitted with custom KAFOs equipped with artificial pneumatic muscles to power ankle plantar flexion/dorsiflexion and knee extension/flexion. Subjects walked over ground at 1.25 m/s under four conditions without extensive practice: 1) without wearing the orthosis, 2) wearing the orthosis with artificial muscles turned off, 3) wearing the orthosis activated under direct proportional myoelectric control, and 4) wearing the orthosis activated under proportional myoelectric control with flexor inhibition produced by leg extensor muscle activation. We collected joint kinematics, ground reaction forces, electromyography, and orthosis kinetics. Results The KAFO produced ~22%–33% of the peak knee flexor moment, ~15%–33% of the peak extensor moment, ~42%–46% of the peak plantar flexor moment, and ~83%–129% of the peak dorsiflexor moment during normal walking. With flexor inhibition produced by leg extensor muscle activation, ankle (Pearson r-value = 0.74 ± 0.04) and knee ( r = 0.95 ± 0.04) joint kinematic profiles were more similar to the without orthosis condition compared to when there was no flexor inhibition (r = 0.49 ± 0.13 for ankle, p = 0.05, and r = 0.90 ± 0.03 for knee, p = 0.17). Conclusion The proportional myoelectric control with flexor inhibition allowed for a more normal gait than direct proportional myoelectric control. The current orthosis design

  16. A pneumatically powered knee-ankle-foot orthosis (KAFO with myoelectric activation and inhibition

    Directory of Open Access Journals (Sweden)

    Ferris Daniel P

    2009-06-01

    Full Text Available Abstract Background The goal of this study was to test the mechanical performance of a prototype knee-ankle-foot orthosis (KAFO powered by artificial pneumatic muscles during human walking. We had previously built a powered ankle-foot orthosis (AFO and used it effectively in studies on human motor adaptation, locomotion energetics, and gait rehabilitation. Extending the previous AFO to a KAFO presented additional challenges related to the force-length properties of the artificial pneumatic muscles and the presence of multiple antagonistic artificial pneumatic muscle pairs. Methods Three healthy males were fitted with custom KAFOs equipped with artificial pneumatic muscles to power ankle plantar flexion/dorsiflexion and knee extension/flexion. Subjects walked over ground at 1.25 m/s under four conditions without extensive practice: 1 without wearing the orthosis, 2 wearing the orthosis with artificial muscles turned off, 3 wearing the orthosis activated under direct proportional myoelectric control, and 4 wearing the orthosis activated under proportional myoelectric control with flexor inhibition produced by leg extensor muscle activation. We collected joint kinematics, ground reaction forces, electromyography, and orthosis kinetics. Results The KAFO produced ~22%–33% of the peak knee flexor moment, ~15%–33% of the peak extensor moment, ~42%–46% of the peak plantar flexor moment, and ~83%–129% of the peak dorsiflexor moment during normal walking. With flexor inhibition produced by leg extensor muscle activation, ankle (Pearson r-value = 0.74 ± 0.04 and knee ( r = 0.95 ± 0.04 joint kinematic profiles were more similar to the without orthosis condition compared to when there was no flexor inhibition (r = 0.49 ± 0.13 for ankle, p = 0.05, and r = 0.90 ± 0.03 for knee, p = 0.17. Conclusion The proportional myoelectric control with flexor inhibition allowed for a more normal gait than direct proportional myoelectric control. The current

  17. Differences between native and prosthetic knees in terms of cross-sectional morphology of the femoral trochlea: a study based on three-dimensional models and virtual total knee arthroplasty.

    Science.gov (United States)

    Du, Zhe; Chen, Shichang; Yan, Mengning; Yue, Bing; Wang, You

    2017-04-20

    The cross-sectional morphology of the prosthetic knee is crucial to understanding patellar motion and quadriceps strength after total knee arthroplasty. However, few comparative evaluations of the cross-sectional morphology of the femoral trochlea have been performed in the native knee and currently available femoral implants, and the relationship between the trochlear anatomy of prosthetic components and post-operative patellofemoral complications remains unclear. We aimed to investigate the differences in cross-sectional morphology of the femoral trochlea between native knees and prosthetic femoral components. Virtual total knee arthroplasty was performed, whereby four different femoral components (medial-pivot, Triathlon, NRG and NexGen) were virtually superimposed onto three-dimensional models of 42 healthy femurs. The following morphological parameters were measured in three cross-sections (0, 45 and 90°) of the femoral trochlea: sulcus height, lateral tilt angle, medial tilt angle and sulcus angle. Only statistically significant differences are described further (p prosthetic components had smaller lateral tilt angles and larger medial tilt angles. In the 45° cross-section, sulcus height was larger in the native knee than in the medial-pivot, Triathlon and NexGen components; both lateral and medial tilt angles were smaller in the prosthetic components. In the 90° cross-section, sulcus height was smaller in the native knee than in the medial-pivot component; all prosthetic components had a larger lateral tilt angle and smaller medial tilt angle. In all cross-sections, the sulcus angle was smaller in the native knee. The discrepancy between native and prosthetic trochlear geometries suggests altered knee mechanics after total knee arthroplasty, but further cadaveric, computational or fluoroscopic investigations are necessary to clarify the implications of this observation. Our findings can be used to optimize biomechanical guidelines for total knee

  18. Biomechanical analysis of the human finger extensor mechanism during isometric pressing.

    Directory of Open Access Journals (Sweden)

    Dan Hu

    Full Text Available This study investigated the effects of the finger extensor mechanism on the bone-to-bone contact forces at the interphalangeal and metacarpal joints and also on the forces in the intrinsic and extrinsic muscles during finger pressing. This was done with finger postures ranging from very flexed to fully extended. The role of the finger extensor mechanism was investigated by using two alternative finger models, one which omitted the extensor mechanism and another which included it. A six-camera three-dimensional motion analysis system was used to capture the finger posture during maximum voluntary isometric pressing. The fingertip loads were recorded simultaneously using a force plate system. Two three-dimensional biomechanical finger models, a minimal model without extensor mechanism and a full model with extensor mechanism (tendon network, were used to calculate the joint bone-to-bone contact forces and the extrinsic and intrinsic muscle forces. If the full model is assumed to be realistic, then the results suggest some useful biomechanical advantages provided by the tendon network of the extensor mechanism. It was found that the forces in the intrinsic muscles (interosseus group and lumbrical are significantly reduced by 22% to 61% due to the action of the extensor mechanism, with the greatest reductions in more flexed postures. The bone-to-bone contact force at the MCP joint is reduced by 10% to 41%. This suggests that the extensor mechanism may help to reduce the risk of injury at the finger joints and also to moderate the forces in intrinsic muscles. These apparent biomechanical advantages may be a result of the extensor mechanism's distinctive interconnected fibrous structure, through which the contraction of the intrinsic muscles as flexors of the MCP joint can generate extensions at the DIP and PIP joints.

  19. Direct repair of the sagittal band for extensor tendon subluxation caused by finger flicking.

    Science.gov (United States)

    Hong, In Tae; Oh, Chi Hoon; Sim, Young Suk; Han, Soo Hong

    2017-09-01

    For patients with metacarpophalangeal (MCP) extensor tendon subluxation caused by finger flicking injury, we performed an extensor tendon realignment and direct repair technique. The purpose of this study was to evaluate the clinical outcome after direct repair of the sagittal band in patients with MCP extensor tendon subluxation caused by finger flicking injury and to introduce the repair technique. A total of 26 patients with a mean age of 39.9 years were included in the study. The mean time from injury to surgery was 51.3 days. The ruptured sagittal band was reattached to the lateral side of the extensor tendon using a continuous interlocking suture. Patients were evaluated for pain using a visual analog scale (VAS), range of motion, long fingertip pinch strength, disabilities of the arm, shoulder, and hand (DASH) score, and the recurrence of extensor tendon subluxation or dislocation. All patients had full range of motion compared to the uninjured contralateral digit. Long fingertip pinch strength was also comparable to that of the contralateral digit in all patients. The DASH score was also improved from a preoperative average of 28.8 to a postoperative average of 1.0. Realignment of the extensor tendon and direct repair of the superficial layer of the sagittal band to the extensor digitorum communis (EDC) tendon is recommended as a treatment option in patients with chronic MCP extensor tendon subluxation, as well as for acute MCP extensor tendon subluxation in patients that have failed or could not maintain conservative treatment approaches.

  20. Spontaneous Rupture of the Extensor Pollicis Longus Tendon due to Unusual Etiology

    Directory of Open Access Journals (Sweden)

    Süleyman Taş

    2014-03-01

    Full Text Available Background: The etiology of spontaneous rupture of the extensor pollicis longus tendon includes systemic or local steroid injections, wrist fracture, tenosynovitis, synovitis, rheumatoid arthritis, and repetitive wrist motions. Case Report: We encountered a case of extensor pollicis longus tendon rupture with an unusual etiology, cow milking. In this case, transfer of the extensor indicis proprius tendon was performed successfully. At 1 year after surgery, extension of the thumb was sufficient. Conclusion: It appears that patients with occupations involving repetitive motions are at a high risk of closed tendon ruptures.

  1. Rupture of the extensor hood of the fifth toe: a rare injury.

    Science.gov (United States)

    Venturini, Sara; Gaba, Suchi; Mangwani, Jitendra

    2017-02-27

    Closed injuries of the extensor hood of the lesser toes are rare and seldom reported in the literature. We present the case of a woman aged 25 years who presented to the orthopaedic fracture clinic with a 2-week history of pain in the left fifth toe and inability to extend following a ballet dancing session. Investigations showed no fracture on plain radiographs, but an ultrasound scan demonstrated rupture to the extensor hood of the little toe. Successful surgical repair of the extensor hood was performed, and the patient made a good recovery with return to dancing activities. 2017 BMJ Publishing Group Ltd.

  2. Extensor digitorum longus tenosynovitis caused by talar head impingement in an ultramarathon runner: a case report.

    Science.gov (United States)

    Kobayashi, H; Sakurai, M; Kobayashi, T

    2007-08-01

    Stenosing tenosynovitis of the extensor digitorum longus tendon is an injury related to ultramarathon running. A 32-year-old male ultramarathon runner developed chronic tenosynovitis of the ankle dorsiflexors. He was diagnosed with extensor digitorum longus tenosynovitis caused by talar head impingement associated with exostosis. He failed to respond to non-operative management and decided to undergo tenosynovectomy of the extensor digitorum longus tendon. The pain was relieved without functional disturbance of the foot and ankle, and the patient returned to running 3 weeks postoperatively. At the 2-year follow-up, he was participating fully in ultramarathons.

  3. Evaluating anterior knee pain.

    Science.gov (United States)

    Hong, Engene; Kraft, Michael C

    2014-07-01

    Musculoskeletal complaints account for about 20% to 30% of all primary care office visits; of these visits, discomfort in the knee, shoulder, and back are the most prevalent musculoskeletal symptoms. Having pain or dysfunction in the front part of the knee is a common presentation and reason for a patient to see a health care provider. There are a number of pathophysiological etiologies to anterior knee pain. This article describes some of the common and less common causes, and includes sections on diagnosis and treatment for each condition as well as key points. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Measuring postural control during mini-squat posture in men with early knee osteoarthritis.

    Science.gov (United States)

    Petrella, M; Gramani-Say, K; Serrão, P R M S; Lessi, G C; Barela, J A; Carvalho, R P; Mattiello, S M

    2017-04-01

    Studies have suggested a compromised postural control in individuals with knee osteoarthritis (OA) evidenced by larger and faster displacement of center of pressure (COP). However, quantification of postural control in the mini-squat posture performed by patients with early knee OA and its relation to muscle strength and self-reported symptoms have not been investigated. The main aim of this cross-sectional, observational, controlled study was to determine whether postural control in the mini-squat posture differs between individuals with early knee OA and a control group (CG) and verify the relation among knee extensor torque (KET) and self-reported physical function, stiffness and pain. Twenty four individuals with knee OA grades I and II (OAG) (mean age: 52.35±5.00) and twenty subjects without knee injuries (CG) (mean age: 51.40±8.07) participated in this study. Participants were assessed in postural control through a force plate (Bertec Mod. USA), which provided information about the anterior-posterior (AP) and medial-lateral (ML) COP displacement during the mini-squat, in isometric, concentric and eccentric knee extensor torque (KET) (90°/s) through an isokinetic dynamometer (BiodexMulti-Joint System3, Biodex Medical Incorporation, New York, NY, USA), and in self-reported symptoms through the WOMAC questionnaire. The main outcomes measured were the AP and ML COP amplitude and velocity of displacement; isometric, concentric, and eccentric KET and self-reported physical function, stiffness and pain. No significant differences were found between groups for postural control (p>0.05). Significant lower eccentric KET (p=0.01) and higher scores for the WOMAC subscales of pain (p=knee OA to prevent postural instability and the need to include quadriceps muscle strengthening, especially by eccentric contractions. The relationship between the self-reported symptoms and a lower and slower COP displacement suggest that the postural control strategy during tasks with a

  5. Partial knee replacement

    Science.gov (United States)

    ... candidate for partial knee replacement and what the success rate is for your condition. Alternative Names Unicompartmental ... ADAM Health Solutions. About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow ...

  6. Knee arthroscopy - discharge

    Science.gov (United States)

    ... pillows. Place the pillows under your foot or calf muscle. This helps control swelling in your knee. For ... time. You have swelling or pain in your calf muscle. Your foot or toes look darker than normal ...

  7. Anterior knee pain

    Science.gov (United States)

    ... thighbone where the kneecap normally rests is too shallow. You have flat feet. Anterior knee pain is ... the principles of the Health on the Net Foundation (www.hon.ch). The information provided herein should ...

  8. Intra-Articular Analgesia and Steroid Reduce Pain Sensitivity in Knee OA Patients: An Interventional Cohort Study

    Directory of Open Access Journals (Sweden)

    Tanja Schjødt Jørgensen

    2014-01-01

    Full Text Available Objectives. To assess the effects of intra-articular therapy on pain sensitivity in the knee and surrounding tissues in knee OA patients. Methods. Twenty-five knee OA patients with symptomatic knee OA were included in this interventional cohort study. Pressure pain thresholds (PPT were recorded before, immediately after, and two weeks after ultrasound guided intra-articular injection of lidocaine combined with glucocorticosteroid. Computer-controlled and manual pressure algometers were used to assess PPT on the knee, vastus lateralis, tibialis anterior, and the extensor carpi radialis longus muscles (control site. Results. Significantly increased PPTs were found following intra-articular injection, at both the knee P<0.0001 and the surrounding muscles P<0.042. The treatment effects were sustained for two weeks, and at some points the effect was even greater at two weeks P<0.026. Albeit not statistically significant, a similar trend was observed at the control site. Conclusions. Intra-articular anesthesia, combined with glucocorticosteroid, reduced pain sensitivity in both the knee and surrounding muscles for at least two weeks.

  9. Knee posture during gait and global functioning post-stroke: a theoretical ICF framework using current measures in stroke rehabilitation.

    Science.gov (United States)

    Rosa, Marlene Cristina Neves; Marques, Alda; Demain, Sara; Metcalf, Cheryl D

    2015-01-01

    To characterise the global functioning post-stroke in patients with normal knee posture (NKP) and abnormal knee posture (AKP) during loading-response. 35 people, 6 months post-stroke. with NKP and AKP were identified and assessed using clinical measures classified into the corresponding International Classification of Functioning, Disability and Health (ICF) domains: weight function (body mass index); muscle power (knee isometric strength); muscle tone (Modified Ashworth Scale); voluntary motor control (Leg sub-score of Fugl-Meyer scale); walking short distances (5-meter walk test; Timed-Up and Go test); walking on different surfaces (Functional Ambulation Categories); moving around (Falls Efficacy Scale); moving using equipment (walking aids) and global assessment of function (WHODAS II). Age, gender, marital status, current occupation and caregivers support characterised personal factors. Patients with AKP had significantly lower knee flexor strength, higher knee flexor and extensor spasticity, more difficulty in maintaining a standing position, walking short and long distances, used walking aids more often and needed more caregiver support. Restriction in activities and participation were correlated with knee flexor strength for AKP and with knee spasticity for NKP group. AKP restricts functioning and participation.

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

    Science.gov (United States)

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

    2017-01-01

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

  11. Dashboard (in the) knee.

    Science.gov (United States)

    Patel, M S; Qureshi, A A; Green, T P

    2015-03-01

    We present the case of a 19-year-old individual presenting to an orthopaedic outpatient clinic several months following a dashboard knee injury during a road traffic accident with intermittent mechanical symptoms. Despite unremarkable examination findings and normal magnetic resonance imaging, the patient was identified subsequently as having an intra-articular plastic foreign body consistent with a piece of dashboard on arthroscopic knee assessment, the retrieval of which resulted in a complete resolution of symptoms.

  12. Is the Sørensen test valid to assess muscle fatigue of the trunk extensor muscles?

    Science.gov (United States)

    Demoulin, Christophe; Boyer, Mathieu; Duchateau, Jacques; Grosdent, Stéphanie; Jidovtseff, Boris; Crielaard, Jean-Michel; Vanderthommen, Marc

    2016-01-01

    Very few studies have quantified the degree of fatigue characterized by the decline in the maximal voluntary contraction (MVC) force of the trunk extensors induced by the widely used Sørensen test. Measure the degree of fatigue of the trunk extensor muscles induced by the Sørensen test. Eighty young healthy subjects were randomly divided into a control group (CG) and an experimental group (EG), each including 50% of the two genders. The EG performed an isometric MVC of the trunk extensors (pre-fatigue test) followed by the Sørensen test, the latter being immediately followed by another MVC (post-fatigue test). The CG performed only the pre- and post-fatigue tests without any exertion in between. The comparison of the pre- and post-fatigue tests revealed a significant (Pmuscles to generate maximal force, and indicates that this test is valid for the assessment of fatigue in trunk extensor muscles.

  13. Wearing an active spinal orthosis improves back extensor strength in women with osteoporotic vertebral fractures

    DEFF Research Database (Denmark)

    Valentin, Gitte Hoff; Pedersen, Louise Nymann; Maribo, Thomas

    2014-01-01

    extensor strength can result in decreased kyphosis and thus a decreased risk of falls and fractures.Objectives:The aim was to examine the effects of an active spinal orthosis - Spinomed III - on back extensor strength, back pain and physical functioning in women with osteoporotic vertebral fractures.......Study design:Experimental follow-up.Methods:The women used the active spinal orthosis for 3 months. Outcomes were changes in isometric back extensor strength, changes in back pain and changes in physical functioning.Results:A total of 13 women were included in the trial. Wearing the orthosis during a 3-month...... period was associated with an increase in back extensor strength of 50% (p = 0.01). The study demonstrated a 33% reduction in back pain and a 6.5-point improvement in physical functioning. The differences in pain and physical functioning were borderline significant.Conclusion:The women demonstrated...

  14. Relationships of Muscle Function and Subjective Knee Function in Patients After ACL Reconstruction.

    Science.gov (United States)

    Bodkin, Stephan; Goetschius, John; Hertel, Jay; Hart, Joe

    2017-07-01

    After anterior cruciate ligament reconstruction (ACLR), relationships between objective measures of muscle function and patient-reported outcomes may change over time. Examining these measures at different time frames after surgery may help develop individualized approaches to improve post-ALCR analysis. To examine the associations between subjective knee function and lower-extremity muscle function in individual patients at various time points after ACLR. Descriptive laboratory study. Fifty-one participants who underwent primary, unilateral ACLR (15 males, 36 females; mean age, 22.9 ± 4.5 years; mean height, 172.4 ± 10.1 cm; mean weight, 68.7 ± 13.1 kg) were separated into 3 groups depending on time since surgery (early, 5 years). Subjective knee function was quantified using the International Knee Documentation Committee (IKDC) subjective knee form and the Knee injury and Osteoarthritis Outcome Score (KOOS). Isometric knee extension and flexion strength were collected at 90 deg/s. Single-leg hop performance was measured using the single hop, triple hop, cross-over hop, and 6-m timed hop. Coefficient correlations were calculated between subjective knee function and objective measures of muscle function for each group. The early group demonstrated moderate correlations between the KOOS and unilateral measures of flexion peak torque ( r = 0.514, P = .035) and flexion power ( r = 0.54, P = .027). The middle group demonstrated the strongest correlations between the KOOS and symmetry measures of the single hop ( r = 0.69, P = .002) and extension work ( r = 0.71, P = .002) as well as unilateral measures of the triple hop ( r = 0.52, P = .034) and extension work ( r = 0.66, P = .004). The late group demonstrated strong correlations between the 6-m timed hop symmetry and the IKDC ( r = 0.716, P = .001) and KOOS ( r = 0.71, P = .001). Patients with a post-ACLR status of less than 2 years exhibited stronger relationships with unilateral strength measures to subjective

  15. Cortical activity differs between position- and force-control knee extension tasks.

    Science.gov (United States)

    Poortvliet, Peter C; Tucker, Kylie J; Finnigan, Simon; Scott, Dion; Sowman, Paul; Hodges, Paul W

    2015-12-01

    Neural control differs between position- and force-control tasks as evident from divergent effects of fatigue and pain. Unlike force-control tasks, position-control tasks focus on a postural goal to maintain a joint angle. Cortical involvement is suggested to be less during postural control, but whether this differs between position- and force-control paradigms remains unclear. Coherence estimates the functional communication between spatially distinct active regions within the cortex (cortico-cortical coherence; CCC) and between the cortex and muscles (corticomuscular coherence; CMC). We investigated whether cortical involvement differed between force-control and more posturally focused, position-control tasks. Seventeen adults performed position- and force-control knee extensor efforts at a submaximal load (10 % maximum voluntary contraction). Surface electromyography was recorded from the right knee extensor and flexor muscles and brain activity using electroencephalography (EEG). CCC and CMC in the beta (13-30 Hz) and gamma (30-45 Hz) frequency bands were calculated between combinations of intra- and inter-hemispheric pairs of electrodes, and between four EEG electrodes that approximated the left motor cortical area, and right knee extensor EMG, respectively. Differences in EEG power and muscle activity were also calculated. CCC was greater across distributed regions in the force-control task. Beta EEG power in the left hemisphere was higher for the position-control task. Although averaged CMC data differed between tasks, there was no task difference for individual CMC data. Muscle activity and force did not differ between tasks. The results demonstrate differential cortical contributions to control force- versus position-control tasks. This might contribute to differences in performance outcomes of these tasks that have been shown previously.

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

    Science.gov (United States)

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

    2016-01-01

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

  17. Identified ankle extensor and flexor motoneurons display different firing profiles in the neonatal rat

    DEFF Research Database (Denmark)

    Cotel, Florence; Antri, Myriam; Barthe, Jean-Yves

    2009-01-01

    population of flexor motoneurons solely exhibited the type II profile, characterized by a frequency-current (F-I) relationship with a clockwise hysteresis. In contrast, in addition to this type II profile, the other three profiles of repetitive firing (type I, III and IV) were observed in extensor...... postnatal development, a significant part of the population of extensor motoneurons, but not flexors, are able to produce self-sustained discharges known to involve the activation of persistent inward currents....

  18. Taking care of your new knee joint

    Science.gov (United States)

    Knee arthroplasty - precautions; Knee replacement - precautions ... After you have knee replacement surgery , you will need to be careful about how you move your knee, especially for the first few ...

  19. Isokinetic knee joint test in "gonalgia sine materia".

    Science.gov (United States)

    Macchi, Claudio; Popolizio, Arcangelo; Casamorata, Francesca; Bicchi, Stefania; Pieroni, Angela; Molino Lova, Raffaele; Miniati, Benedetta; Gulisano, Massimo; Catini, Claudio; Conti, Andrea A; Gensini, Gian Franco

    2002-01-01

    Fifty-four subjects, aged between 20 and 35 years, divided into two subgroups, respectively 30 healthy subjects (17 males and 13 females) and 24 subjects with "gonalgia sine materia" (13 males and 11 females) underwent isokinetic exercise test in order to compare their dominant limb with the not dominant one as regard as the strength of extensor and flexor muscles of the knee. No statistically significant difference was found in any of the studied parameters in the comparison between the dominant limb and the not dominant one, both within the subgroup of healthy subjects and within the subgroup of subjects with "gonalgia sine materia". Authors conclude that psychological features may play a preeminent role in the genesis, as well as in the maintenance of "gonalgia sine materia", thus confirming previous data available in medical literature.

  20. Clinical Significance of Presence of Extensor Indicis Brevis Manus – A Case Report

    Directory of Open Access Journals (Sweden)

    N Esakkiammal

    2017-11-01

    Full Text Available Anatomical variations of additional muscles and tendons are commonly encountered in extensor aspect of forearm and hand during surgeries and dissections. There are reports on different kinds of variations like, extra tendons, additional bellies, and abnormal attachments of the muscle. Surgeons should have the knowledge about these variations for muscle or tendon grafting and also to plan surgeries. While dissecting the extensor compartment forearm and dorsum of hand of an elderly female cadaver, an anomalous muscle belly was noticed on dorsum of hand bilaterally alongwith the main tendon of extensor indicis muscle. This additional belly of extensor indicis muscle was called Extensor Indicis Brevis Manus (EIBM. This muscle originated from the dorsal carpal ligament and joined the main tendon of extensor indicis muscle in both the hands. Awareness of existence of this kind of variation is important for clinicians and surgeons for a correct diagnosis and eventual surgery in patients presenting with a cyst on the dorsum of hand, to avoid accidental mishaps.

  1. [The isokinetic evaluation of the knee joint function following the autoplastic correction of its anterior cross-shaped ligament].

    Science.gov (United States)

    Akhpashev, A A; Novikova, L V; Agzamov, D S; Orudzhev, F Kh

    2016-01-01

    The flexors/extensors imbalance can be a cause knee instability and therefore lead to progression of osteoarthritis. The isokinetic evaluation of the strength of flexors after the autoplastic reconstruction the anterior cross-shaped (cruciate) ligament (ACL) is of primary importance bearing in mind that certain authors have reported a persistent deficiency in flexor strength after surgery. The purpose of the present study was to objectively evaluate the isokinetic function of the knee during each treatment stage and estimate the influence of harvesting semitendinosus/gracilis tendon (SGT) on the knee flexion. During the period from 2012 to 2014, a total of 44 patients (20 women and 24 men) presenting with ACL rupture were available for the examination. All the patients underwent the isokinetic evaluation of the knee function before operation, 6-8 weeks and 3-4 months after the arthroscopic ACL reconstruction with the use of the SGT graft. The patients were divided into two groups. The first group was comprised of 22 subjects who were treated in accordance with the standard protocol of therapeutic physical exercises starting from week 6 after the initiation of the physiotherapeutic rehabilitative measures. The second group consisted of 22 patients who had to perform the isokinetic training within 6-8 weeks after surgery. The results of the study indicate that all the patients suffering injuries to the anterior cross-shaped ligaments had well apparent flexor/extensor imbalance. In those of the first group, the flexor imbalance amounted to 25-35% while the extensor imbalance was 10-15% within 3-4 months after the surgery. The second group showed a 10-15% flexor imbalance and 2-5% extensor imbalance after 3-4 months. The isokinetic testing provides a tool for the objective evaluation of the knee function. It helps to reveal the high effectiveness of isokinetic rehabilitation protocol leading to the recovery of the patients within 3-4 months after the surgery. It can be

  2. Knee pain in competitive swimming.

    Science.gov (United States)

    Rodeo, S A

    1999-04-01

    The high volume of training in competitive swimming results in cumulative overload injuries. Knee pain ranks second to shoulder pain as a common complaint in competitive swimmers. Most knee pain occurs on the medial side of the knee and, most commonly, in breaststroke swimmers; however, knee pain may accompany all strokes. This article reviews the incidence of knee pain, the biomechanic and anatomic factors predisposing to injury, specific injury patterns, injury diagnosis, and the treatment and prevention of injury to the knee in swimmers.

  3. Association between frontal plane knee control and lower extremity injuries: a prospective study on young team sport athletes

    Science.gov (United States)

    Pasanen, Kati; Krosshaug, Tron; Vasankari, Tommi; Kannus, Pekka; Heinonen, Ari; Kujala, Urho M; Avela, Janne; Perttunen, Jarmo; Parkkari, Jari

    2018-01-01

    Background/aim Poor frontal plane knee control can manifest as increased dynamic knee valgus during athletic tasks. The purpose of this study was to investigate the association between frontal plane knee control and the risk of acute lower extremity injuries. In addition, we wanted to study if the single-leg squat (SLS) test can be used as a screening tool to identify athletes with an increased injury risk. Methods A total of 306 basketball and floorball players participated in the baseline SLS test and a 12-month injury registration follow-up. Acute lower extremity time-loss injuries were registered. Frontal plane knee projection angles (FPKPA) during the SLS were calculated using a two-dimensional video analysis. Results Athletes displaying a high FPKPA were 2.7 times more likely to sustain a lower extremity injury (adjusted OR 2.67, 95% CI 1.23 to 5.83) and 2.4 times more likely to sustain an ankle injury (OR 2.37, 95% CI 1.13 to 4.98). There was no statistically significant association between FPKPA and knee injury (OR 1.49, 95% CI 0.56 to 3.98). The receiver operating characteristic curve analyses indicated poor combined sensitivity and specificity when FPKPA was used as a screening test for lower extremity injuries (area under the curve of 0.59) and ankle injuries (area under the curve of 0.58). Conclusions Athletes displaying a large FPKPA in the SLS test had an elevated risk of acute lower extremity and ankle injuries. However, the SLS test is not sensitive and specific enough to be used as a screening tool for future injury risk. PMID:29387448

  4. Relationship between lower limb muscle strength, self-reported pain and function, and frontal plane gait kinematics in knee osteoarthritis.

    Science.gov (United States)

    Park, Sang-Kyoon; Kobsar, Dylan; Ferber, Reed

    2016-10-01

    The relationship between muscle strength, gait biomechanics, and self-reported physical function and pain for patients with knee osteoarthritis is not well known. The objective of this study was to investigate these relationships in this population. Twenty-four patients with knee osteoarthritis and 24 healthy controls were recruited. Self-reported pain and function, lower-limb maximum isometric force, and frontal plane gait kinematics during treadmill walking were collected on all patients. Between-group differences were assessed for 1) muscle strength and 2) gait biomechanics. Linear regressions were computed within the knee osteoarthritis group to examine the effect of muscle strength on 1) self-reported pain and function, and 2) gait kinematics. Patients with knee osteoarthritis exhibited reduced hip external rotator, knee extensor, and ankle inversion muscle force output compared with healthy controls, as well as increased peak knee adduction angles (effect size=0.770; p=0.013). Hip abductor strength was a significant predictor of function, but not after controlling for covariates. Ankle inversion, hip abduction, and knee flexion strength were significant predictors of peak pelvic drop angle after controlling for covariates (34.4% unique variance explained). Patients with knee osteoarthritis exhibit deficits in muscle strength and while they play an important role in the self-reported function of patients with knee osteoarthritis, the effect of covariates such as sex, age, mass, and height was more important in this relationship. Similar relationships were observed from gait variables, except for peak pelvic drop, where hip, knee, and ankle strength remained important predictors of this variable after controlling for covariates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Knee Muscles Isokinetic Evaluation after a Six-Month Regular Combined Swim and Dry-Land Strength Training Period in Adolescent Competitive Swimmers.

    Science.gov (United States)

    Dalamitros, Athanasios A; Manou, Vasiliki; Christoulas, Kosmas; Kellis, Spiros

    2015-12-22

    Previous studies demonstrated significant increases in the shoulder internal rotators' peak torque values and unilateral muscular imbalances of the shoulder rotators after a competitive swim period. However, there are no similar data concerning the knee muscles. The purpose of the current study was to examine the effects of a six-month training period on knee flexor and extensor peak torque values, examine a possible bilateral strength deficit and evaluate the unilateral strength balance in competitive swimmers. Eleven male adolescent swimmers (age: 14.82 ± 0.45 years) were tested for concentric knee extension and flexion peak torque (60°/s) with an isokinetic dynamometer, before and after a regular combined swim and dry-land strength training period. A trend towards greater improvements in the knee extensor compared to flexor muscles peak torque was observed. Furthermore, the bilateral strength deficit remained almost unchanged, whereas unilateral strength imbalance was increased for both limbs. However, all results were non-significant (p > 0.05). According to the data presented, a six-month regular combined swim and dry-land strength training period caused non-significant alterations for all the parameters evaluated during isokinetic testing. This study highlights the fact that competitive adolescent swimmers demonstrated unilateral knee strength imbalances throughout a long period of their yearly training macrocycle.

  6. Knee Muscles Isokinetic Evaluation after a Six-Month Regular Combined Swim and Dry-Land Strength Training Period in Adolescent Competitive Swimmers

    Directory of Open Access Journals (Sweden)

    Dalamitros Athanasios A.

    2015-12-01

    Full Text Available Previous studies demonstrated significant increases in the shoulder internal rotators’ peak torque values and unilateral muscular imbalances of the shoulder rotators after a competitive swim period. However, there are no similar data concerning the knee muscles. The purpose of the current study was to examine the effects of a six-month training period on knee flexor and extensor peak torque values, examine a possible bilateral strength deficit and evaluate the unilateral strength balance in competitive swimmers. Eleven male adolescent swimmers (age: 14.82 ± 0.45 years were tested for concentric knee extension and flexion peak torque (60°/s with an isokinetic dynamometer, before and after a regular combined swim and dry-land strength training period. A trend towards greater improvements in the knee extensor compared to flexor muscles peak torque was observed. Furthermore, the bilateral strength deficit remained almost unchanged, whereas unilateral strength imbalance was increased for both limbs. However, all results were nonsignificant (p > 0.05. According to the data presented, a six-month regular combined swim and dry-land strength training period caused non-significant alterations for all the parameters evaluated during isokinetic testing. This study highlights the fact that competitive adolescent swimmers demonstrated unilateral knee strength imbalances throughout a long period of their yearly training macrocycle.

  7. Salvage of infected total knee arthroplasty with Ilizarov external fixator

    Directory of Open Access Journals (Sweden)

    Venkata Gurava Reddy

    2011-01-01

    Full Text Available Background: Knee arthrodesis may be the only option of treatment in cases of chronic infected total knee arthroplasty (TKA with concomitant irreparable extensor mechanism disruption, extensive bone loss or severe systemic morbidities. Circular external fixation offers possible progressive adjustment to stimulate the bony fusion and to make corrections in alignment. We evaluated the results of knee arthrodesis with one or two stage circular external fixator for infected TKA. Materials and Methods: 16 cases of femoro-tibial fusion were retrospectively evaluated. Male-to-female ratio was 10:6. Mean age of the patients was 62.2 years. Cierney-Mader classification was used for anatomical and physiological evaluation while the bone stock deficiency was classified into mild, moderate and severe. Surgical technique involved either single or two stage arthrodesis using circular external fixator. Results: Union was achieved in 15 patients (93.75%. The mean duration for union (frame application time in these patients was 28.33 weeks (range 22 to 36 weeks. Analysis showed that in the group with frame application time of less than 28 weeks, the incidence of mild to moderate bone deficiency was 83.33%, while in the frame application time more than 28 weeks group the incidence was 20% (P-value 0.034. Similarly the incidence of Cierney-Mader 4B (Bl, Bs, Bls was found to be 33.33% in the group of frame application time of less than 28 weeks, while it was 90% in the group with frame application time more than 28 weeks (P-value 0.035. Conclusion: Circular external fixator is a safe and reliable method to achieve knee arthrodesis in cases of deep infection following TKA. Severe bone stock deficiency and Cierney- Mader type B host are likely risk factors for prolonged frame application time. We recommend a two-stage procedure especially when there is compromised host or severe bone loss.

  8. How to quantify knee function after total knee arthroplasty?

    NARCIS (Netherlands)

    Boonstra, M.C.; Waal Malefijt, M.C. de; Verdonschot, N.J.J.

    2008-01-01

    Total knee arthroplasty (TKA) is being undertaken in a younger population than before and as a result the functional demands on the knee are likely to be increasing. As a consequence, it is important to define quantitative functional knee tests that can monitor any increase. A valuable functional

  9. Knee arthrography today

    International Nuclear Information System (INIS)

    Otto, H.; Kallenberger, R.

    1987-01-01

    The role of knee arthrography today is demonstrated and technical problems are discussed. Among a lot of variants the position of the patient and the choice of contrast media play a great part concerning the result of the examination. Mild complications occur in 0.25% of the examinations, severe and live threatening complications are extremely rare. Diagnosis of meniscal lesions is most important for knee arthrography; arthroscopy and arthrography are complementary examinations and not mutually exclusive, they achieve combined an accuracy of 97-98%. In the same way arthrography is able to evaluate the condropathy of the femoro-tibial joint, whereas accuracy of arthroscopy in the diagnosis of patellar chondropathy is much higher. There is a great reliability of arthrography regarding the evaluation of lesions of the capsule, but accuracy in lesions of the cruciate ligaments is low. Arthrography is very suitable for evaluation of Baker-cysts, since indications for almost occuring internal derangement of the knee are even available. Knee arthrography is a complex and safe procedure with very less discomfort for the patient; it has a central position in the evaluation of lesions of the knee. (orig.) [de

  10. Anatomical variation of radial wrist extensor muscles: a study in cadavers

    Directory of Open Access Journals (Sweden)

    Soubhagya Ranjan Nayak

    2008-01-01

    Full Text Available OBJECTIVE: The tendons of the extensor carpi radialis longus and brevis muscles are quite useful in tendon transfer, such as in correction of finger clawing and restoration of thumb opposition. Knowledge of additional radial wrist extensor muscle bellies with independent tendons is useful in the above-mentioned surgical procedures. METHODS: The skin, subcutaneous tissue, and antebrachial fascia of 48 (24 on the right side and 24 on left side male upper limb forearms were dissected. The following aspects were then analyzed: (a the presence of additional muscle bellies of radial wrist extensors, (b the origin and insertion of the additional muscle, and (c measurements of the muscle bellies and their tendons. RESULTS: Five out of 48 upper limbs (10.41% had additional radial wrist extensors; this occurred in 3 out of 24 left upper limbs (12.5% and 2 out of 24 right upper limbs (8.3%. In one of the right upper limbs, two additional muscles were found. The length and width of each additional muscle belly and its tendon ranged between 2 - 15cm by 0.35 - 6.4cm and 2.8 - 20.8cm by 0.2 0.5cm, respectively. The additional radial wrist extensor tendons in our study basically originated either from the extensor carpi radialis longus or brevis muscles and were inserted at the base of the 2nd or 3rd metacarpal bone. CONCLUSION: The present study will inform surgeons about the different varieties of additional radial wrist extensors and the frequency of their occurrence.

  11. Bouncy knee in a semi-automatic knee lock prosthesis.

    Science.gov (United States)

    Fisher, L D; Lord, M

    1986-04-01

    The Bouncy Knee concept has previously proved of value when fitted to stabilised knee units of active amputees. The stance phase flex-extend action afforded by a Bouncy Knee increased the symmetry of gait and also gave better tolerance to slopes and uneven ground. A bouncy function has now been incorporated into a knee of the semi-automatic knee lock design in a pilot laboratory trial involving six patients. These less active patients did not show consistent changes in symmetry of gait, but demonstrated an improved ability to walk on slopes and increased their walking range. Subjective response was positive, as noted in the previous trials.

  12. Traumatic knee extension deficit (the locked knee)

    DEFF Research Database (Denmark)

    Helmark, I C; Neergaard, K; Krogsgaard, M R

    2007-01-01

    . Evaluating MRI, all grade-3 meniscal lesions were considered able to cause a mechanical block as well as acute partial or total anterior cruciate ligament (ACL)-ruptures. ACL-ruptures with an old appearance were not considered able to cause locking. Assuming that arthroscopy was the gold standard......, the following results were calculated for the overall appearance of a lesion able to cause locking: Positive predictive value = 0.85, negative predictive value = 0.77, sensitivity = 0.95, specificity = 0.53. Two knees were erroneously evaluated with no mechanical locking at MRI (one bucket-handle lesion and one...

  13. Effect of acute dietary nitrate intake on maximal knee extensor speed and power in healthy men and women

    OpenAIRE

    Coggan, Andrew R.; Leibowitz, Joshua L.; Kadkhodayan, Ana; Thomas, Deepak T.; Ramamurthy, Sujata; Spearie, Catherine Anderson; Waller, Suzannea; Farmer, Marsha; Peterson, Linda R.

    2014-01-01

    Nitric oxide (NO) has been demonstrated to enhance the maximal shortening velocity and maximal power of rodent muscle. Dietary nitrate (NO3-) intake has been demonstrated to increase NO bioavailability in humans. We therefore hypothesized that acute dietary NO3- intake (in the form of a concentrated beetroot juice (BRJ) supplement) would improve muscle speed and power in humans. To test this hypothesis, healthy men and women (n=12; age=22-50 y) were studied using a randomized, double-blind, p...

  14. Comparison of the Effects of Massage and Cryotherapy on the Knee Extensor Muscles Fatigue and Isokinetic Parameters in Soccer Players

    Directory of Open Access Journals (Sweden)

    Mohsen Razeghi

    2015-03-01

    Full Text Available Background: Fatigue can cause a significant effect on the mechanics of complex motor skills and reduce physical and mental efficiency. One of the common ways to reduce fatigue is passive recovering or using massage and cryotherapy after exercise. The present study aimed to compare the effects of massage and cryotherapy on muscles fatigue and isokinetic parameters. Methods: This study was conducted on 54 healthy athletes aged 20-30 years who were randomly divided into three groups: cooling (ice therapy, massage, and control (resting. Each of the volunteers was evaluated in two sessions. The first session was to familiarize the participants with isokinetic contraction. The second session started with a brief warm up subsequently, using Biodex Isokinetic System Average Peak Torque (APTQ, Average Power (AP, and Total Work (TW were measured. Then, the fatigue protocol was applied. Afterwards, interventions were performed for 15 minutes. After the intervention, isokinetic parameters were evaluated again. Also, perceived fatigue and Fatigue Index (FI were recorded before and after the intervention. Results: APTQ, AP, and TW significantly increased in massage and cryotherapy groups after the intervention, while perceived fatigue and FI decreased significantly in both conditions (P0.05, but perceived fatigue and FI decreased significantly (P0.05. Conclusion: Massage and cryotherapy could increase isokinetic parameters and decrease FI and perceived fatigue. Therefore, massage and cryotherapy have been more effective than rest as a strategy to return to normal state and no significant difference was observed between these two groups.

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

    DEFF Research Database (Denmark)

    Krustrup, Peter; Söderlund, Karin; Relu, Mihai U.

    2009-01-01

    temperature increase (DeltaT(m)) in RF was 0.52+/-0.09 degrees C, which was 57% and 73% higher (Pdegrees C, which was not different from VM but 54% higher (P... twitch (FT) fibres was 81% and 91% of resting levels, respectively, with lower (Pvalues 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...

  16. Impairment-targeted exercises for older adults with knee pain: protocol for a proof-of-principle study

    Directory of Open Access Journals (Sweden)

    Thomas Elaine

    2011-01-01

    Full Text Available Abstract Background Exercise therapy for knee pain and osteoarthritis remains a key element of conservative treatment, recommended in clinical guidelines. Yet systematic reviews point to only modest benefits from exercise interventions. One reason for this might be that clinical trials tend to use a one-size-fits-all approach to exercise, effectively disregarding the details of their participants' clinical presentations. This uncontrolled before-after study (TargET-Knee-Pain aims to test the principle that exercises targeted at the specific physical impairments of older adults with knee pain may be able to significantly improve those impairments. It is a first step towards testing the effectiveness of this more individually-tailored approach. Methods/Design We aim to recruit 60 participants from an existing observational cohort of community-dwelling older adults with knee pain. Participants will all have at least one of the three physical impairments of weak quadriceps, a reduced range of knee flexion and poor standing balance. Each participant will be asked to undertake a programme of exercises, targeted at their particular combination and degree of impairment(s, over the course of twelve weeks. The exercises will be taught and progressed by an experienced physiotherapist, with reference to a "menu" of agreed exercises for each of the impairments, over the course of six fortnightly home visits, alternating with six fortnightly telephone calls. Primary outcome measures will be isometric quadriceps strength, knee flexion range of motion, timed single-leg standing balance and the "Four Balance Test Scale" at 12 weeks. Key secondary outcome measures will be self-reported levels of pain, stiffness and difficulties with day-to-day functional tasks (WOMAC. Outcome measures will be taken at three time-points (baseline, six weeks and twelve weeks by a study nurse blinded to the exercise status of the participants. Discussion This study (TargET-Knee

  17. Influence of functional knee bracing on the isokinetic and functional tests of anterior cruciate ligament deficient patients.

    Directory of Open Access Journals (Sweden)

    Niyousha Mortaza

    Full Text Available Use of functional knee braces has been suggested to provide protection and to improve kinetic performance of the knee in Anterior cruciate ligament(ACL-injured patients. However, many athletes might refrain from wearing the braces because of the fear of performance hindrance in the playing field. The aim of this study was to examine the effect of three functional knee brace/sleeves upon the isokinetic and functional performance of ACL-deficient and healthy subjects. Six anterior cruciate ligament deficient (29.0 ± 5.3 yrs., 175.2 ± 5.4 cm, and 73.0 ± 10.0 kg and six healthy male subjects (27.2 ± 3.7 yrs., 176.4 ± 6.4 cm, and 70.3 ± 6.9 kg were selected. The effect of a custom-made functional knee brace, and two neoprene knee sleeves, one with four metal supports and one without support were examined via the use of isokinetic and functional tests in four sets (non-braced,wearing functional knee brace,and wearing the sleeves. Cross-over hop and single leg vertical jump test were performed and jump height, and hop distance were recorded. Peak torque to body weight ratio and average power in two isokinetic velocities(60°.s(-1,180°.s(-1 were recorded and the brace/sleeves effect was calculated as the changes in peak torque measured in the brace/sleeves conditions, expressed as a percentage of peak torque measured in non-braced condition. Frequency content of the isokinetic torque-time curves was also analyzed. Wilcoxon signed rank test was used to compare the measured values in four test conditions within each control and ACL-deficient group,and Mann-Whitney U test was used for the comparison between the two groups. No significant differences in peak torque, average power, torque-time curve frequency content, vertical-jump and hop measurements were found within the experimental and the non-braced conditions (p>0.05. Although the examined functional knee brace/sleeves had no significant effect on the knee muscle performance, there have been

  18. HIGH REPETITION JUMP TRAINING COUPLED WITH BODY WEIGHT SUPPORT IN A PATIENT WITH KNEE PAIN AND PRIOR HISTORY OF ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION: A CASE REPORT.

    Science.gov (United States)

    Elias, Audrey R C; Kinney, Anthony E; Mizner, Ryan L

    2015-12-01

    Patients frequently experience long-term deficits in functional activity following anterior cruciate ligament reconstruction, and commonly present with decreased confidence and poor weight acceptance in the surgical knee. Adaptation of neuromuscular behaviors may be possible through plyometric training. Body weight support decreases intensity of landing sufficiently to allow increased training repetition. The purpose of this case report is to report the outcomes of a subject with a previous history of anterior cruciate ligament (ACL) reconstruction treated with high repetition jump training coupled with body weight support (BWS) as a primary intervention strategy. A 23-year old female, who had right ACL reconstruction seven years prior, presented with anterior knee pain and effusion following initiation of a running program. Following visual assessment of poor mechanics in single leg closed chain activities, landing mechanics were assessed using 3-D motion analysis of single leg landing off a 20 cm box. She then participated in an eight-week plyometric training program using a custom-designed body weight support system. The International Knee Documentation Committee Subjective Knee Form (IKDC) and the ACL-Return to Sport Index (ACL-RSI) were administered at the start and end of treatment as well as at follow-up testing. The subject's IKDC and ACL-RSI scores increased with training from 68% and 43% to 90% and 84%, respectively, and were retained at follow-up testing. Peak knee and hip flexion angles during landing increased from 47 ° and 53 ° to 72 ° and 80 ° respectively. Vertical ground reaction forces in landing decreased with training from 3.8 N/kg to 3.2 N/kg. All changes were retained two months following completion of training. The subject experienced meaningful changes in overall function. Retention of mechanical changes suggests that her new landing strategy had become a habitual pattern. Success with high volume plyometric training is

  19. Multiple extensor tendons reconstruction with hamstring tendon grafts and flap coverage for severe dorsal hand injuries.

    Science.gov (United States)

    Ozbaydar, M; Orman, O; Ozel, O; Altan, E

    2017-12-01

    Treatment of patients with traumatic loss of skin and multiple extensor tendons on the dorsum of the hand is a challenge. The aim of this study was to assess the outcome after reconstruction of soft tissues and multiple extensor tendons in patients who suffered traumatic loss of skin and multiple extensor tendons. Ten patients were enrolled in the study. These patients underwent single-stage reconstruction with autogenous hamstring tendon grafts for multiple extensor tendon defects and fasciocutaneous flaps for coverage of dorsal hand defects. In total, 25 tendons (2 tendons in 5 patients and 3 tendons in 5 patients) were reconstructed. The semitendinosus tendon was used in all patients and the gracilis tendon was added in five patients for tendon reconstruction. Total tendon length requiring reconstruction was between 9cm and 31cm. Free anterolateral thigh flaps were used in six patients and reverse pedicled forearm flaps were used in four patients. According to Miller's scoring system, 8 fingers had excellent results, 12 fingers had good results and 5 fingers had fair results at the final follow-up. Hamstring tendons can be used satisfactorily for primary reconstruction of multiple digital extensor tendons due to their availability and compatibility, with a fasciocutaneous flap. IV. Copyright © 2017 SFCM. Published by Elsevier Masson SAS. All rights reserved.

  20. The influence of lumbar extensor muscle fatigue on lumbar-pelvic coordination during weightlifting.

    Science.gov (United States)

    Hu, Boyi; Ning, Xiaopeng

    2015-01-01

    Lumbar muscle fatigue is a potential risk factor for the development of low back pain. In this study, we investigated the influence of lumbar extensor muscle fatigue on lumbar-pelvic coordination patterns during weightlifting. Each of the 15 male subjects performed five repetitions of weightlifting tasks both before and after a lumbar extensor muscle fatiguing protocol. Lumbar muscle electromyography was collected to assess fatigue. Trunk kinematics was recorded to calculate lumbar-pelvic continuous relative phase (CRP) and CRP variability. Results showed that fatigue significantly reduced the average lumbar-pelvic CRP value (from 0.33 to 0.29 rad) during weightlifting. The average CRP variability reduced from 0.17 to 0.15 rad, yet this change ws statistically not significant. Further analyses also discovered elevated spinal loading during weightlifting after the development of lumbar extensor muscle fatigue. Our results suggest that frequently experienced lumbar extensor muscle fatigue should be avoided in an occupational environment. Lumbar extensor muscle fatigue generates more in-phase lumbar-pelvic coordination patterns and elevated spinal loading during lifting. Such increase in spinal loading may indicate higher risk of back injury. Our results suggest that frequently experienced lumbar muscle fatigue should be avoided to reduce the risk of LBP.

  1. Structural Diversity of the Extensor Digitorum Profundus Muscle Complex in Platyrrhini.

    Science.gov (United States)

    Novikova, Mellin A; Panyutina, Aleksandra A

    2017-01-01

    Separate extension of fingers in the hand of primates is performed by 3 muscles: m. extensor pollicis longus, m. extensor digiti secundi, and m. extensor digitorum lateralis. Here it is proposed to consider them as parts of the extensor digitorum profundus muscular complex. The diversity in structure of these muscles in primates is examined based both on original anatomical study of New World monkeys and analysis of extensive published data on primates from different taxonomic groups. It is shown that in these muscles there are 2 main types of structure variations - the division of the muscle belly into several heads which give rise to separate tendons, and the split of the single terminal tendon into several branches. The first type of modification ensures the possibility of a separate management of the fingers, and the second, on the contrary, ensures the coupled control of extension of fingers. A scheme of evolutionary transformations of muscles belonging to the complex of the deep extensors of fingers is proposed. © 2017 S. Karger AG, Basel.

  2. The Effects of Forward Head Posture on Neck Extensor Muscle Thickness: An Ultrasonographic Study.

    Science.gov (United States)

    Goodarzi, Fereshte; Rahnama, Leila; Karimi, Noureddin; Baghi, Raziyeh; Jaberzadeh, Shapour

    2018-01-01

    This study aimed to compare neck extensor muscle thickness, thickness changes, and strength between participants with forward head posture (FHP) and controls with normal head posture (NHP). Twenty college students with FHP (mean age 21.30 ± 2.36 years) and 20 students with NHP (mean age 21.85 ± 2.78 years) participated in this case-control study. The thickness of neck extensor muscles was measured at rest and at maximal voluntary isometric contraction (MVIC). In addition, the craniovertebral angle (CVA) was calculated. To compare thickness changes between the 2 groups and among 5 muscles, a 2-way repeated measures analysis of variance was applied. In addition, Pearson's correlation test was performed to investigate the relationship between neck extensor MVIC and CVA. The FHP group demonstrated lower MVIC compared with the NHP group (P = .03). Semispinalis capitis showed the smallest thickness changes during neck extensor MVIC in FHP compared with the controls (P < .001). However, no significant difference in terms of muscle thickness was observed between the 2 groups at the state of rest (P = .16-.99). A positive association was also found between the MVIC and CVA (P = .02). Semispinalis capitis had less thickness changes during MVIC of neck extensors in individuals with FHP compared with those with NHP. This indirectly implies lower activity of this muscle in FHP condition. This study finding may help researchers develop therapeutic exercise protocols to manage FHP. Copyright © 2017. Published by Elsevier Inc.

  3. Ultrasound findings in injuries of dorsal extensor hood: Correlation with MR and follow-up findings

    International Nuclear Information System (INIS)

    Kichouh, Mimoun; De Maeseneer, Michel; Jager, Tjeerd; Marcelis, Stefaan; Van Hedent, Eddy; Van Roy, Peter; De Mey, Johan

    2011-01-01

    Objective: The aim of this study was to use ultrasound to examine the dorsal hood in nine patients with a clinical suspicion of dorsal hood injuries. Material and methods: Clinical and imaging files from interesting case logbooks of nine patients were reviewed. Ultrasound was performed by one of the three radiologists experienced in musculoskeletal ultrasound. The examinations were also performed in flexion and in flexion with resistance. MR correlation was obtained in six patients. One patient underwent surgery. To obtain anatomical correlation of the normal dorsal hood 2 embalmed hand specimens were dissected. Results: The sagittal bands were easily depicted in the transverse plane on ultrasound images and presented as hypoechoic bands on both sides of the extensor communis tendons. Injuries of the sagittal bands were seen on ultrasound as hypoechoic thickening of the sagittal bands at the side of the extensor tendons. The normal shape of the sagittal bands was also no longer recognizable. Subluxations or dislocations of the extensor tendons were also seen. When the injuries were located in the fibrous slips between the extensor indicis and the extensor communis of the second finger, subluxations with an increased distance between these 2 tendons were seen, especially in flexion, or in flexion with resistance. Conclusion: Ultrasound is a valuable tool for the assessment of the injuries of the dorsal hood and is an easily available method for the diagnosis of the fine soft tissue components of the dorsal hood region.

  4. Rheumatoid wrist deformity and risk of extensor tendon rupture evaluated by 3DCT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Hajime; Abe, Asami; Murasawa, Akira; Nakazono, Kiyoshi; Horizono, Hidehiro; Ishii, Katsushi; Seki, Eiko [Niigata Rheumatic Center, Department of Rheumatology, Shibata city, Niigata (Japan)

    2010-05-15

    Extensor tendon rupture on the dorsum of the wrist is commonly seen in patients with rheumatoid arthritis (RA). It causes immediate dysfunction of the hand and surgical reconstruction is usually required. The purpose of this study was to clarify the risk of extensor tendon rupture by quantifying wrist deformity on three-dimensional computed tomography (3DCT) images. Three-dimensional CT images of 108 wrists in 102 patients with RA and 38 wrists in 38 healthy volunteers were analyzed retrospectively. All of the rheumatoid wrists had caused persistent pain for more than 6 months despite ongoing medical treatment. Extensor tendon rupture was noted in 49 wrists in 47 patients, and no rupture was noted in 59 wrists in 56 patients. The dorsal subluxation ratio (DSR) of the ulnar head and the carpal supination angle (CSA) were measured utilizing a new technique. The average DSR and CSA in the rupture group (n = 49), the non-rupture group (n = 59), and the normal wrist group (n = 38) were 37%, 19%, and 26%, and 15 , 11 , and 6 respectively. The cut-off values for extensor tendon rupture in the wrists of patients with RA were 32% (sensitivity; 70%, specificity; 75%) in the DSR, and 14 (71%, 68%) in the CSA. By utilizing 3DCT imaging of the rheumatoid wrist, these parameters can help improve our ability to predict extensor tendon rupture. (orig.)

  5. Progressive resistance exercise in women with osteoarthritis of the knee: a randomized controlled trial.

    Science.gov (United States)

    Jorge, Renata Trajano Borges; Souza, Marcelo Cardoso de; Chiari, Aline; Jones, Anamaria; Fernandes, Artur da Rocha Correa; Lombardi Júnior, Império; Natour, Jamil

    2015-03-01

    To determine the effect of a progressive resistance exercise (PRE) program on women with osteoarthritis (OA) of the knee. Eligible subjects included women aged 40 to 70 years with pain between 3 and 8 on a 10-cm pain scale. Among the 144 subjects screened, 60 met the eligibility criteria and were randomized to the experimental group (EG) or control group (CG). Subjects in the EG participated in a 12-week PRE program twice a week and CG remained on a waiting list for physical therapy. The PRE program consisted of strengthening exercises for knee extensors, knee flexors, hip abductors and hip adductors, all performed with 50% and 70% of the one-repetition maximum (1RM) using machines with free weights. Resistance was reevaluated every two weeks. Assessments of pain, muscle strength, walking distance, function and quality of life were performed at baseline, six weeks and 12 weeks by a blinded assessor. Twenty-nine female subjects were randomly assigned to the EG and 31 were randomly assigned to the CG. Repeated-measures ANOVA revealed significantly better results in the EG pain (from 7.0±1.3 to 4.3±3.1 in the EG and from 7.0±1.2 to 6.6±1.5 in the CG - pmuscle strength (extensors: p<0.001; flexors: p=0.002; and abductors: p<0.001). The PRE program was effective in reducing pain and improving function, some quality of life domains and strength in women with OA of the knee. © The Author(s) 2014.

  6. Heat generated by knee prostheses.

    Science.gov (United States)

    Pritchett, James W

    2006-01-01

    Temperature sensors were placed in 50 knees in 25 patients who had one or both joints replaced. Temperature recordings were made before walking, after walking, and after cycling. The heat generated in healthy, arthritic, and replaced knees was measured. The knee replacements were done using eight different prostheses. A rotating hinge knee prosthesis generated a temperature increase of 7 degrees C in 20 minutes and 9 degrees C in 40 minutes. An unconstrained ceramic femoral prosthesis articulating with a polyethylene tibial prosthesis generated a temperature increase of 4 degrees C compared with a healthy resting knee. The other designs using a cobalt-chrome alloy and high-density polyethylene had temperature increases of 5 degrees-7 degrees C with exercise. Frictional heat generated in a prosthetic knee is not immediately dissipated and may result in wear, creep, and other degenerative processes in the high-density polyethylene. Extended periods of elevated temperature in joints may inhibit cell growth and perhaps contribute to adverse performance via bone resorption or component loosening. Prosthetic knees generate more heat with activity than healthy or arthritic knees. More-constrained knee prostheses generate more heat than less-constrained prostheses. A knee with a ceramic femoral component generates less heat than a knee with the same design using a cobalt-chromium alloy.

  7. Arthroscopic surgery for degenerative knee

    DEFF Research Database (Denmark)

    Thorlund, Jonas Bloch; Juhl, C B; Roos, E M

    2015-01-01

    OBJECTIVE: To determine benefits and harms of arthroscopic knee surgery involving partial meniscectomy, debridement, or both for middle aged or older patients with knee pain and degenerative knee disease. DESIGN: Systematic review and meta-analysis. MAIN OUTCOME MEASURES: Pain and physical function....... RESULTS: The search identified nine trials assessing the benefits of knee arthroscopic surgery in middle aged and older patients with knee pain and degenerative knee disease. The main analysis, combining the primary endpoints of the individual trials from three to 24 months postoperatively, showed a small...... included symptomatic deep venous thrombosis (4.13 (95% confidence interval 1.78 to 9.60) events per 1000 procedures), pulmonary embolism, infection, and death. CONCLUSIONS: The small inconsequential benefit seen from interventions that include arthroscopy for the degenerative knee is limited in time...

  8. Anterior approach for knee arthrography

    International Nuclear Information System (INIS)

    Zurlo, J.V.; Towers, J.D.; Golla, S.

    2001-01-01

    Objective. To develop a new method of magnetic resonance arthrography (MRA) of the knee using an anterior approach analogous to the portals used for knee arthroscopy.Design. An anterior approach to the knee joint was devised mimicking anterior portals used for knee arthroscopy. Seven patients scheduled for routine knee MRA were placed in a decubitus position and under fluoroscopic guidance a needle was advanced from a position adjacent to the patellar tendon into the knee joint. After confirmation of the needle tip location, a dilute gadolinium solution was injected.Results and conclusion. All the arthrograms were technically successful. The anterior approach to knee MRA has greater technical ease than the traditional approach with little patient discomfort. (orig.)

  9. The floating knee

    DEFF Research Database (Denmark)

    Muñoz Vives, Josep; Bel, Jean-Christophe; Capel Agundez, Arantxa

    2016-01-01

    In 1975, Blake and McBryde established the concept of 'floating knee' to describe ipsilateral fractures of the femur and tibia.1This combination is much more than a bone lesion; the mechanism is usually a high-energy trauma in a patient with multiple injuries and a myriad of other lesions...

  10. The floating knee

    DEFF Research Database (Denmark)

    Muñoz Vives, Josep; Bel, Jean-Christophe; Capel Agundez, Arantxa

    2016-01-01

    fixation when both fractures (femoral and tibial) are extra-articular.Plates are the 'standard of care' in cases with articular fractures.A combination of implants are required by 40% of floating knees.Associated ligamentous and meniscal lesions are common, but may be irrelevant in the case of an intra...

  11. The Relationships Between the Center of Mass Position and the Trunk, Hip, and Knee Kinematics in the Sagittal Plane: A Pilot Study on Field-Based Video Analysis for Female Soccer Players

    Directory of Open Access Journals (Sweden)

    Sasaki Shogo

    2015-03-01

    Full Text Available Athletes with non-contact anterior cruciate ligament tears have common features in the sagittal plane; namely, the body’s center of mass (COM is located posterior to the base of support, the trunk and knee joints are extended, and the hip angle is flexed. However, the relationships among these variables have not been assessed in field-based movements. This study sought to determine relationships between distances from the COM to the base of support and the trunk, hip, and knee positions in women while playing soccer. Sixty events (29 single-leg landing and 31 single-leg stopping events were analyzed using two-dimensional video analysis. The relationships among the measurement variables were determined using the Pearson’s product-moment correlation coefficient, and stepwise multiple linear regression models were used to explore the relationships between the COM position and the kinematic variables. The distance from the COM to the base of support displayed a moderate negative relationship with the trunk angle (r = - 0.623, p < .0001, r2 = 0.388 and a strong positive relationship with the limb angle (r = 0.869, p < .0001, r2 = 0.755. The limb, knee, and trunk angles were selected in the best regression model (adjusted r2 = 0.953, p < .0001, f2 = 20.277. These findings suggest that an increased trunk angle and a decreased limb angle at initial contact are associated with a safer COM position. Neuromuscular training may be useful for controlling the trunk and lower limb positions during dynamic activities.

  12. UTILIZAÇÃO DE EXTENSORES ALTERNATIVOS NA PRODUÇÃO DE COMPENSADOS MULTILAMINADOS

    Directory of Open Access Journals (Sweden)

    Setsuo Iwakiri

    2000-05-01

    Full Text Available Esta pesquisa foi desenvolvida com o objetivo de avaliar a potencialidade de uso de farinhas de soja, arroz, milho, aveia e mandioca, como extensores alternativos a farinha de trigo (testemunha para produção de compensados. Foram produzidas 21 chapas com lâminas de madeira de Eucalyptus cloeziana, sendo três chapas por tratamento, utilizando a seguinte formulação em partes por peso: resina uréia-formaldeído - 100, extensor - 75, água - 80 e catalisador - 7. Os resultados médios de resistência da linha de cola aos esforços de cizalhamento, pelo teste seco e úmido, demostraram que as farinhas de arroz e de aveia podem ser utilizados como extensor alternativo à farinha de trigo.

  13. Alterations in walking knee joint stiffness in individuals wit