Isometric and isokinetic hip strength in males with chronic ankle instability and its relationship with dynamic balance and self-reported instability.

OBJECTIVES

To investigate isometric and isokinetic hip strength as well as dynamic balance in males with chronic ankle instability (CAI) and explore potential associations between hip strength, dynamic balance, and self-reported instability.

DESIGN

Cross-sectional study.

SETTING

University laboratory.

PARTICIPANTS

Fifty male participants (25 with CAI and 25 healthy controls).

MAIN OUTCOME MEASURES: Hip isometric and isokinetic torque normalized to body weight, Lower Quarter Y-balance Test (YBT-LQ), the Polish version of The Cumberland Ankle Instability Tool (CAIT-PL).

RESULTS

Significant differences were observed only in the hip isometric abductors/adductors strength ratio (p = 0.034, ES = 0.65), which was lower in the CAI group. CAI participants showed reduced dynamic balance in posterolateral reach (p = 0.006, ES = 0.92) and composite score of YBT-LQ (p = 0.012, ES = 0.91). There was a moderate positive correlation between dynamic balance and hip abductors strength during posteromedial (r = 0.40, p = 0.049) and posterolateral (r = 0.40, p = 0.048) YBT-LQ reaches, and isometric hip abductors strength moderately positively correlated with self-reported instability (r = 0.46, p = 0.021) in the CAI group.

CONCLUSION

Males with CAI exhibit deficits in frontal plane hip isometric strength, specifically in the hip abductor/adductor ratio, while no deficits were observed in isokinetic strength. The relationships between hip abductors strength, dynamic balance, and self-reported ankle instability may suggest the importance of hip abductors isometric strength for functional outcomes in CAI-patients.