The effect of ankle braces on the prevention of dynamic forced ankle inversion.

Background: Athletes often employ prophylactic braces to reduce the risk of ankle injuries.

Hypothesis: Ankle braces do not significantly decrease the risk of forced inversion on a standardized one-footed jump landing.

Study Design: Controlled laboratory study.

Methods: Fourteen healthy men with a mean age of 25.1 years were tested. Three braces, two semirigid (Aircast and Bledsoe) and one lace-up (Swede-O), were fitted to each subject. Forced dynamic ankle inversion of 24 degrees was to be resisted as the subjects landed on one foot with a force of two body weights on a stimulus presented randomly in 5 of 15 jump trial blocks onto a hard, level force plate. Subjects first completed 1 no-brace block of 5 trials to establish baseline performance, then 3 randomly ordered 15-trial blocks testing performance with each of the braces, and then finally a no-brace 5-trial block.

Results: The average no-brace success rate was 24%, which demonstrated the challenging nature of the task. All three braces increased the success rate (average, 44%); however, only the two semirigid braces proved to be significantly better than the unbraced state.

Conclusion: This test holds promise for evaluating brace efficacy when landing with one foot unexpectedly on an object that acts to forcibly invert the ankle.