Exercise-induced fatigue affects lower limb biomechanics in high-risk backhand smash landings among female badminton players.

This study used one-dimensional statistical parametric mapping (SPM1d) to examine how exercise-induced fatigue affects lower limb biomechanics during landing from high-risk backhand smashes, including the backhand rear-court jump smash (BRJS) and backhand lateral jump smash (BLJS), in elite female badminton players. After fatigue, athletes showed increased hip coronal motion, knee valgus, and trunk lateral tilt, but reduced hip abduction, indicating weakened coronal control. These biomechanical changes suggest an increased risk of anterior cruciate ligament (ACL) injury. BRJS presented a sagittal plane dominant energy absorption strategy, while BLJS presented a coronal plane dominant balance strategy. Overall, exercise-induced fatigue reshapes landing control strategies and induces biomechanical alterations consistent with an elevated risk of ACL injury. In addition, BRJS exhibits biomechanical patterns potentially associated with ankle sprains, whereas BLJS displays loading patterns linked to ACL injury mechanisms, suggesting movement-specific potential injury risks.