A065: Effect of Mental Fatigue on Lower Limb Biomechanics and ACL Injury Risk in Basketball Players

Abstract

Anterior cruciate ligament (ACL) injuries are prevalent among basketball players, particularly during abrupt stop-jump actions. While most existing studies have focused on the impact of physical fatigue on athletic performance, the role of mental fatigue has been largely overlooked. High-intensity games can induce mental fatigue, which may further increase the risk of ACL injuries by altering lower limb biomechanical characteristics. However, the underlying mechanisms remain unclear. This study aimed to investigate the effects of mental fatigue on the biomechanical characteristics of the lower limb during a sharp stop-jump task in basketball players and to assess whether mental fatigue increases potential risk factors associated with ACL injuries. A total of 38 basketball players were recruited via a self-controlled study design. Mental fatigue was induced through a 45-minute Stroop task, with fatigue levels assessed via the visual analogue scale (VAS). Infrared motion capture systems, force platforms, and surface electromyography (EMG) devices were used to measure changes in kinematic, kinetic, and surface EMG data before and after mental fatigue intervention. The Wilcoxon signed-rank test was applied to the effects of mental fatigue on lower limb biomechanical characteristics. Following the induction of mental fatigue, significant decreases were observed in the knee flexion angle (z = -2.211, P = 0.02), internal rotation angle (z = -2.228, P = 0.02), internal rotation moment (z = -2.178, P = 0.02), and median frequency (MDF) of the rectus femoris (z = -3.009, P \u3c 0.01), biceps femoris (z = -3.285, P \u3c 0.01), tibialis anterior (z = -3.053, P \u3c 0.01), and gastrocnemius (z = -2.110, P = 0.03), as well as in the root mean square (RMS) of the tibialis anterior (z = -2.139, P = 0.03). Conversely, significant increases were noted in the peak vertical ground reaction force (z = -2.015, P = 0.04), knee extension moment (z = -2.162, P = 0.03), and RMS of the rectus femoris (z = -2.067, P = 0.03). Studies have demonstrated that mental fatigue negatively impacts the biomechanics of the lower extremities during abrupt stop jumps in basketball players, potentially increasing the risk of ACL injury. Targeted interventions should be developed to prevent the potential impact of mental fatigue on ACL