Tabriz University of Medical Sciences Medical Journal of Tabriz University of Medical Sciences 2783-2031 36 2 2014 06 05 Effect of Fatigue upon Static and Dynamic Balance Control in Athletes with Acute Ankle Sprain 74 79 EN Mehrangiz Qorbani Roqayeh Khansari Sara Mehdizade Jozani Amirreza Sohrabi Journal Article 2013 12 12 2014 01 21 Background and Objectives: The overweighed cases like the patients with the injury of ankle sprain having problems with their Balance control system. The aim of this study was to investigate the effect of fatiguing exercise on the static and dynamic balance changes in athletes with the ankle sprain. Materials and Methods: In this Case- Control study, 30 active athletes and 14 cases with previous severe ankle sprain as case group and 16 healthy cases as control group were inverted in a treadmill running protocol in 2 experimental sessions. Center-of-pressure sway velocity in single-legged stance and time to stabilization (TTS) after a unilateral jump-landing task (first session) and maximum reach distance in the Star Excursion Balance Test (SEBT) (second session) were assessed before and immediately after the treadmill exercise. Results: In the unfatigued condition, between-groups the significant difference was found only in the anterior-posterior TTS (P< 0.5, ES<0.39). Group-by-fatigue interactions were found for mean SEBT (P<0.03, ES <0.43) and anterior-posterior TTS (P<0.02, ES<0.48). Conclusions: Prefatigue versus postfatigue SEBT and TTS tests differences were greater in previously injured athletes, whereas static sway velocity increased similarly in both groups. Fatiguing duo to running significantly affected static and dynamic postural control in participants with a history of ankle sprain. Fatigue-induced alterations of dynamic postural control were greater in athletes with a previous ankle sprain. Thus, even after successful return to competitions, ongoing deficits in sensorimotor control may contribute to the enhanced ankle reinjury risk.