Effects of Mental Fatigue on Gait Performance and Variability

OBJECTIVES Mental fatigue has been shown to negatively impact physical performance, including motor skills and neuromuscular function. This study aimed to investigate the effects of mental fatigue on gait performance and variability in healthy young male adults. METHODS Eighteen participants walked over-ground at their preferred speed before and after completing a mentally fatiguing Stroop task. Kinematic data were recorded to assess gait variables such as speed, step length, step time, and step width, along with their coefficients of variation (CV). Subjective ratings of mental fatigue were also collected. RESULTS While subjective ratings of mental fatigue significantly increased following the Stroop task, no significant changes were observed in gait performance or CV variables at the group level. However, singlesubject analyses revealed that some participants experienced significant increases or decreases in gait speed, suggesting gait performance responses to mental fatigue are individual-specific. CONCLUSIONS These findings indicate that although mental fatigue increases perceptibly, it may not uniformly affect gait performance in simple walking tasks. Factors such as the duration and intensity of the fatigue-inducing task, individual coping strategies, and the nature of the gait task, particularly the participant's preferred speed, likely influenced these results. Future research should explore more complex gait tasks and varied mental fatigue protocols to better understand this relationship.