Hip Abductor Strength Predicts Lateral Non-contact Ankle Sprains in Male Soccer Players

Abstract

PURPOSE: Deficits in hip abductor strength have been linked to increased risk of lower-extremity injury. We aimed to prospectively determine whether preseason hip abductor strength predicts future lateral non-contact ankle sprains in competitive athletes. METHODS: Prior to the start of the sports season, isometric hip abductor strength was assessed bilaterally in competitive soccer players (210 males) using a hand-held dynamometer. During the sport seasons, lateral ankle sprain status was recorded, and injured athletes were further classified based on the mechanism of injury (non-contact vs. contact). Postseason, a logistic model was constructed to determine whether baseline hip abductor strength predicted future lateral non-contact ankle sprains. A receiver operating characteristic (ROC) curve was constructed for hip abductor strength to determine the clinical cut-off value that distinguished between a high-risk and low-risk outcome. RESULTS: A total of 25 lateral non-contact ankle sprains were confirmed for an overall annual incidence of 11.9%. Baseline hip abductor strength was significantly lower in injured athletes compared to non-injured athletes (35.7 ± 5.6 vs. 39.5 ± 6.6 %BW, p = 0.008). Logistic regression indicated impaired hip abductor strength increased future injury risk [OR = 1.10 (95% CI: 1.02, 1.18), p = 0.010]. The clinical cutoff to define high risk was established as hip abductor strength ≤ 33.8 %BW. Using this cutoff, athletes classified as high risk have their probability of injury increase from 11.9% to 26.7%; whereas; athletes classified as low risk have their probability of injury decrease from 11.9% to 8.0%. CONCLUSIONS: Impaired isometric hip abductor strength predisposes competitive male soccer players to lateral non-contact ankle sprains. Screening procedures should consider evaluating isometric hip abductor strength (specifically for high-level male athletes participating in soccer) as preseason hip abductor predicts future lateral non-contact ankle sprains.