Document Type


Date of Award


Degree Name

Master of Arts (MA)


Kinesiology and Sport Management

First Advisor

Hyung Suk Yang


Mental fatigue has been shown to impair physical performance, especially for endurance-based sports. However, little research has been done regarding the impacts of mental fatigue on shorter maximal effort movements during a common sport related activity such as the depth jump. The purpose of this study was to investigate the effects of mental fatigue on short maximal performance efforts and predisposing biomechanical variables for non-contact ACL tears during depth-jumps in 18 Division I female soccer players. Each participant completed five depth jumps, followed by a 30-minute Stroop task to induce mental fatigue, and then completed five more depth jumps. Multiple paired t tests were used to examine the differences in dependent variables across conditions. The findings revealed that jump height decreased (p = .002), reactive strength index decreased (p = .031), peak hip abduction angles left decreased (p = .049), peak hip adduction angles left decreased (p = .003) and angles right increased (p < .001), and angles right increased (p = .049), and peak knee adduction angles right increased (p =.015) after mental fatigue was induced. The observations suggest that mental fatigue may negatively impact depth jump performances, which may represent that mental fatigue may alter plyometric, power, and ballistic movements in sports. The data shows to be inconclusive regarding the lower body kinematics and kinetics in relation to the risk of non-contact ACL tears during landing.

Subject Categories

Biomechanics | Kinesiology


Depth-jump, Mental Fatigue, non-contact ACL tears, soccer

Number of Pages



University of South Dakota

Included in

Biomechanics Commons