Methods: Participants were screened for their balance using the single-leg balance test (SLBT) and were assigned to either the positive or the negative SLBT groups. Fifty-four individuals with CAI (N = 27 per group) were recruited and completed four clinical tests including the foot-lift test (FLT), the time-in-balance test (TIBT), the modified star excursion balance test in the posteromedial (mSEBT-PM) direction and the side-hop test (SHT). The receiver operating characteristics (ROC) curve coupled with Youden index were calculated to determine the optimal cut-off scores of each test.

Results: We found significant differences in balance between groups for all tests, with good to excellent values for the area under the ROC curve (AUC). All four tests reached good to excellent sensitivity and specificity values and had significant cut-off scores to discriminate balance performance among CAI participants.

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.