The effectiveness of a balance training intervention in reducing the incidence of noncontact ankle sprains in high school football players.

BACKGROUND A high body mass index and previous ankle sprains have been shown to increase the risk of sustaining noncontact inversion ankle sprains in high school football players. HYPOTHESIS Stability pad balance training reduces the incidence of noncontact inversion ankle sprains in football players with increased risk. STUDY DESIGN Cohort study; Level of evidence, 2. METHODS Height, body mass, history of previous ankle sprains, and current ankle brace/tape use were documented at the beginning of preseason training in 2 high school varsity football teams for 3 consecutive years (175 player-seasons). Players were categorized as minimal risk, low risk, moderate risk, and high risk based on the history of previous ankle sprain and body mass index. Players in the low-, moderate-, and high-risk groups (ie, any player with a high body mass index and/or a previous ankle sprain) were placed on a balance training intervention on a foam stability pad. Players balanced for 5 minutes on each leg, 5 days per week, for 4 weeks in preseason and twice per week during the season. Postintervention injury incidence was compared with preintervention incidence (107 players-seasons) for players with increased risk. RESULTS Injury incidence for players with increased risk was 2.2 injuries per 1000 exposures (95% confidence interval, 1.1-3.8) before the intervention and 0.5 (95% confidence interval, 0.2-1.3) after the intervention (P < .01). This represents a 77% reduction in injury incidence (95% confidence interval, 31%-92%). CONCLUSION The increased risk of a noncontact inversion ankle sprain associated with a high body mass index and a previous ankle sprain was eliminated by the balance training intervention.