Short-foot exercise program improves static postural control and subjective ankle instability in chronic ankle instability

CONTEXT: Chronic ankle instability (CAI) is associated with weakness and atrophy of the intrinsic foot muscle. Short-foot exercise (SFE) selectively activates the intrinsic foot muscle and has been proposed as a therapeutic intervention. However, evidence supporting its effectiveness in individuals with CAI remains limited. OBJECTIVE: To examine the effects of a 4-week SFE program on static and dynamic postural control and subjective ankle instability in individuals with CAI. DESIGN: Randomized controlled clinical trial. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: We randomly allocated 24 participants with CAI to intervention (n = 12; age = 19.4 ± 0.9 years, height = 167.4 ± 8.6 cm, mass = 61.4 ± 8.6 kg) and control (n = 12; age = 19.5 ± 1.1 years, height = 165.9 ± 8.0 cm, mass = 61.7 ± 8.8 kg) groups. INTERVENTIONS: The intervention group performed the SFE program 3 times per week for 4 weeks. The control group continued usual daily routines without additional training. MAIN OUTCOME MEASURES: We assessed static and dynamic postural control and subjective ankle instability using center-of-pressure measurements during single-legged stance, the Star Excursion Balance Test, and the Cumberland Ankle Instability Tool, respectively, preintervention and postintervention. The data were analyzed using a 2-way repeated-measures analysis of variance (group × time) with an α level of .05. RESULTS: The intervention group showed improvements in static postural control and subjective ankle instability compared with the control group ( < .05). We found no differences in dynamic postural control ( > .05). CONCLUSIONS: Our findings indicated that the 4-week SFE program effectively enhances static postural control and subjective ankle instability in individuals with CAI, supporting its integration into rehabilitation programs.