Abstract
The aim of our study was to investigate the effect of muscle-specific fatigue of the quadriceps and hamstring muscles on the biomechanical factors of anterior cruciate ligament (ACL) injury using musculoskeletal modeling techniques during directional diversion maneuver. Fifteen female subjects performed a directional diversion maneuver under three treatment conditions (quadriceps fatigue, hamstring fatigue, and control gait). Data from the 3D motion capture system and force platform were used to extract anterior/posterior ACL forces using the two-bundle ACL musculoskeletal modeling approach. A decrease in maximum extension (51.3%) and flexion (50.7%) torque after fatigue was observed. After quadriceps fatigue, the extension (p = 0.041) and adduction moments (p = 0.046) of the knee joint and the mean anterior bundle of ACL force (p = 0.021) decreased significantly. The knee flexion angle (p = 0.003), knee valgus angle (p = 0.013), and shear force (p = 0.043) decreased significantly after hamstring fatigue. The decrease in ACL force after quadriceps fatigue confirms its significant role in causing an ACL injury. However, no significant differences in ACL load after hamstring fatigue leads us to speculate that the antagonist muscle group, i.e., the hamstring, might not have a preventive mechanism against ACL injury.
Highlights
Muscular fatigue is one of the major causes of anterior cruciate ligament (ACL) injury since fatigue adversely affects the somatosensory, proprioceptive, and muscular systems [1,2,3]
It is considered that a direct relationship of change in knee kinematics, during a dynamic activity such as directional diversion maneuver (DDM), may not be enough to confirm its effect on ACL load from this study
The ACL load after the HA fatigue did not show statistically significant differences, there was a significant reduction in ACL load after QF fatigue
Summary
Muscular fatigue is one of the major causes of anterior cruciate ligament (ACL) injury since fatigue adversely affects the somatosensory, proprioceptive, and muscular systems [1,2,3]. The adverse effects of fatigue on these systems may lead to a higher prevalence of ACL injury during DDM as it increases transitional and rotational forces exerted by the ACL due to instantaneous positioning and orientation of the lower limb [5,6]. Studies report that approximately 70% of ACL injuries are non-contact in nature, with a three to four times higher prevalence among high school and collegiate age females than men competing in the same sports [7,8,9]. Various studies on walking, running, cutting, and landing have reported females exhibiting greater hip adduction and internal rotation with decreased knee flexion compared to male counterparts [10,11,12,13,14]. The effect of fatigue along with unexpected perturbations may lead to insufficient neuromuscular control and increase the risk of ACL injuries through increased knee valgus posture [15,16,17]
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