Objectives: To investigate the knee flexor torque-angle curve after hamstring strain injury using different muscle action types and angular velocities.
Design: Cross-sectional.
Setting: Controlled laboratory.
Participants: Thirteen collegiate athletes injured hamstring strain (21.0 ± 0.8 years; 173.9 ± 6.5 cm; 70.1 ± 10.5 kg).
Main Outcome Measures: Concentric and eccentric knee flexor torque was measured at 60 & 300°/sec. Peak torque and average torque every 10° were determined from torque-angle curve and injured side was compared with non-injured side.
Results: No significant differences were found in the concentric muscle actions. However, the eccentric peak torque was significantly lower on the injured side at 60°/sec (p = 0.048) and at 300°/sec (p = 0.002). The average eccentric torque was significantly lower on the injured side at 60°/sec from 10° to 20° of knee flexion (p = 0.012-0.018) and at 300°/sec from 10° to 60° of knee flexion (p = 0.005-0.049).
Conclusion: The knee flexor torque-angle curve changes with eccentric muscle action after hamstring injury. Eccentric torque declines were close to full knee extension at 60°/sec and a wide range of knee flexion at 300°/sec. The assessment and rehabilitation of eccentric hamstring strength may be important to consider the effect of the angular velocity after hamstring strain injury.
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http://dx.doi.org/10.1016/j.ptsp.2021.11.008 | DOI Listing |
J Biomech
October 2024
Institute for Liberal Arts, Tokyo Institute of Technology, Meguro-ku, Tokyo, Japan.
Although foot mobility tends to be greater in females, sex-based differences in foot torsional stiffness have not been investigated. It is also unclear whether assessing the medial longitudinal arch (MLA) height reflects foot torsional stiffness. This study included 52 healthy adults (26 females and 26 males) with an average age of 24.
View Article and Find Full Text PDFHeliyon
July 2024
School of Intelligent Manufacturing, Chengdu Technological University, Chengdu, 610031, PR China.
Carbon fiber reinforced composite structures have been a research hotspot in recent years, with 9 specimens designed for static tests under bending and torsion loads of CFRP concrete filled steel tubes. The torque angle (-) curve was studied from an experimental perspective. Subsequently, a reasonable finite element model was established using ABAQUS software.
View Article and Find Full Text PDFKnee Surg Sports Traumatol Arthrosc
September 2024
Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan.
Purpose: This study aimed to identify factors influencing persistent muscle weakness in knee flexor strength after anterior cruciate ligament (ACL) reconstruction using the hamstring tendon and establish a clear cut-off value at 3 months postoperatively for the limb symmetry index (LSI) to exceed 90% at 6 months postoperatively.
Methods: One hundred forty-eight patients undergoing ACL reconstruction were included and categorised into two groups based on knee flexor strength at 6 months postoperatively: patients with LSI of 90% or greater (achieved group: n = 114) and patients with LSI less than 85% (nonachieved group: n = 34). Items with significant differences between the two groups (preoperative waiting period, LSI to body weight ratio of knee flexor and extensor strength at 3 months postoperatively and peak torque angle of knee flexor muscle) were included in the multiple logistic regression analysis.
Front Sports Act Living
April 2024
Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
Introduction: Parkinson's disease (PD) is a prevalent neurodegenerative condition observed primarily in the elderly population that gives rise to motor and non-motor symptoms, one of which is muscle weakness. The aim of this study was to characterize the vastus lateralis torque-fascicle length (T-L) and the knee extensors torque-angular velocity (T-V) and power-angular velocity (P-V) relationships in PD patients and to investigate the influence of muscle geometry on muscle mechanics.
Methods: Participants (11 PD: patients, 9 CR: age matched healthy controls; 10 CY: young healthy controls) performed: (i) isometric contractions (e.
J Biomech Eng
August 2024
Systems Design Engineering Department, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
Muscle torque generators (MTGs) have been developed as an alternative to muscle-force models, reducing the muscle-force model complexity to a single torque at the joint. Current MTGs can only be applied to single Degree-of-freedom (DoF) joints, leading to complications in modeling joints with multiple-DoFs such as the shoulder. This study aimed to develop an MTG model that accounts for the coupling between 2-DoF at the shoulder joint: shoulder plane of elevation (horizontal abduction/adduction) and shoulder elevation (flexion/extension).
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