Differential Impact of Cognitive Tasks on Postural Stability in Individuals Following Anterior Cruciate Ligament...

Anterior cruciate ligament reconstruction (ACLR) can result in persistent deficits in postural stability particularly under dual-task conditions involving cognitive demands. This study investigated the effects of cognitive tasks from different domains on postural control among individuals with ACLR compared with healthy controls. Twenty-five individuals with ACLR and 25 asymptomatic matched controls performed three cognitive tasks of backward counting (working memory), Stroop Color-Word Test (executive function), and Benton's Judgment of Line Orientation (visuospatial perception) under single- (seated) and dual-task (single-leg stance on rigid and foam surfaces) conditions. Postural stability was quantified by measuring center-of-pressure sway area and sway velocity in anterior-posterior and medial-lateral directions. Cognitive performance was evaluated by counting task errors. Results indicated significantly greater postural sway in the ACLR group compared with controls across all tasks (p < .01), with the Stroop Color-Word Test significantly increasing mean sway velocity compared with the no-task condition (p < .01) in only the ACLR group. ACLR participants also demonstrated consistently greater cognitive errors under all conditions. However, cognitive errors were not significantly affected by increased postural difficulty. Findings suggest that executive function tasks uniquely exacerbate postural control deficits following ACLR, highlighting the clinical importance of incorporating targeted cognitive-postural training focusing on executive control into rehabilitation protocols.