A 6-Week Nine-Square Exercise Programme for Collegiate Athletes with Chronic Ankle Instability: A Randomised Controlled Trial

Background: Individuals with chronic ankle instability (CAI) have poor postural stability, functional limitations and low quality of life. Although nine-square exercise can improve postural control, there is limited evidence demonstrating whether it can function as an alternative CAI rehabilitation programme. This study aimed to determine the effects of nine-square exercise on postural stability and self-reported outcomes in individuals with CAI. Methods: Eighteen male collegiate athletes with CAI participated in either a 6-week nine-square exercise or a control group (n = 9 per group). At baseline and post-intervention, the participants undertook clinical tests to measures dynamic and static postural control, and self- reported outcomes regarding ankle stability and function. Results: Within-group differences, the nine-square exercise group experienced improved dynamic postural control (P = 0.004), static postural control (P = 0.001) and self-reported outcomes (P < 0.05). For the control group, only static postural control improved (P = 0.018). Post- intervention, the nine-square exercise group experienced significant improvements in dynamic postural control (P < 0.001), ankle stability (P = 0.002) and functional ability (P < 0.05) relative to the control group. Conclusion: These findings suggest that the nine-square exercise can offer an alternative rehabilitation programme for improving postural control, self-perceived ankle stability and functional ability in CAI.