Using Asymmetries in Lower-Limb Functional Performance to Predict Non-Contact Ankle Sprains: A Prospective Study in 318 Youth Taekwondo Athletes

Objective: To investigate the relationship between inter-limb asymmetries in lower limb power and dynamic balance and non-contact ankle sprains in youth taekwondo athletes. Methods: A total of 318 male youth taekwondo athletes (9.03±2.02) yearscompleted the single-leg countermovement jump, hop, and triple-hop test, and the star excursion balance test(SEBT) was also conducted, then the inter-limb asymmetries of performance was calculated for each test. Subsequently, all participants were followed up for 12 months to record the occurrence of non-contact ankle sprains. The data were analyzed by using the Mann-Whitney U test,logistic regression analysis, and receiver operating characteristic(ROC) curve analysis. Results: During the follow-up period, 23individuals experienced non-contact ankle sprains. The increased inter-limb asymmetry in single-leg countermovement jump height significantly elevated the risk of non-contact ankle sprains(adjusted OR=1.050 for 1% increase in asymmetry; 95% CI: 1.016~1.084; P=0.003). An inter-limb asymmetry in single-leg countermovement jump height of 14.16% was determined as the optimal cutoff point for predicting non-contact ankle sprains in male youth taekwondo athletes(asymmetry ≥14.16% vs. <14.16%: adjusted OR=5.089; 95% CI: 1.996~12.974; P=0.001). Conclusions: Inter-limb asymmetries in single-leg countermovement jump height can be used to assess the risk of non-contact ankle sprains in male youth taekwondo athletes. However, inter-limb asymmetries in performance of single-leg hop, triple-hop and SEBT cannot be applied in predicting the risk of ankle sprains in youth athletes.