Association Between Functional Ankle Instability and Strength, Postural Stability, and Functional Performance in Adolescent Soccer Players

OBJECTIVES Functional ankle instability (FAI) is common in adolescent soccer players following recurrent ankle sprains and may influence physical function. This study aimed to examine the association between the severity of perceived ankle instability, assessed using the Korean version of the Cumberland Ankle Instability Tool (CAIT-K), and ankle strength, postural stability, and functional performance in adolescent soccer players.METHODS A total of 105 adolescent soccer players with CAIT-K scores of 25 or lower participated in this crosssectional study. Ankle muscle strength was assessed in four directions. Dynamic postural stability was assessed using the Star Excursion Balance Test, and static postural stability was evaluated using the center of pressure (CoP) ellipse area during single-leg stance. Functional performance was measured using the figure-8 hop test and the lateral hop test. Simple linear regression analyses were performed to examine associations between CAIT-K scores and outcome variables.RESULTS CAIT-K scores were not significantly associated with ankle muscle strength, dynamic postural stability, or functional performance (all p > 0.05). However, a significant association was found between CAIT-K scores and static postural stability, with lower CAIT-K scores associated with a larger CoP ellipse area (p < 0.001).CONCLUSIONS Greater severity of perceived FAI was associated with impaired static postural stability but not with ankle strength, dynamic balance, or functional performance. Static postural stability assessment may be useful for identifying functional deficits related to ankle instability in adolescent soccer players.