Hip external rotation isometric torque for soccer, basketball, and volleyball athletes: normative data and asymmetry index.

BACKGROUND:Deficits in strength of the hip external rotators (ER) affect trunk, hip, and knee movement patterns, potentially contributing to injury in athletes. OBJECTIVES:To provide normative data on isometric torque for hip ER in athletes of three distinct sports and to determine if isometric torque for the hip ER and torque asymmetry between legs differ among sports and between sexes. METHODS:Basketball, soccer, and volleyball athletes (n=451) were evaluated. Hip ER torque was quantified bilaterally with athletes in prone and 90° of knee flexion using a hand-held dynamometer. RESULTS:Data are expressed as mean and 95% confidence interval. Hip ER torque values in Nm/kg for the dominant and non-dominant limbs were, respectively, 0.46 (0.44, 0.48) and 0.42 (0.40, 0.44) for male soccer athletes; 0.35 (0.32, 0.37) and 0.27 (0.25, 0.29) for male basketball athletes; and 0.37 (0.34, 0.39) and 0.35 (0.32, 0.37) for male volleyball athletes. Hip ER torque in Nm/kg for the female volleyball athletes was 0.29 (0.26, 0.33) for the dominant and 0.29 (0.25, 0.32) for the non-dominant limb. The Limb Symmetry Index for male soccer, basketball, and volleyball players was, respectively, 94% (91, 97), 81% (75, 87), and 95% (91, 99). For female volleyball players the Limb Asymmetry Index was 102% (95, 108). Male volleyball athletes showed higher torque values than female volleyball athletes. CONCLUSIONS:This study reported normative values for hip ER isometric torque of youth athletes. Clinicians can use the reported data as reference to identify torque deficits in athletes of the three reported sports.