Normative data for hip strength, flexibility and stiffness in male soccer athletes and effect of age and limb dominance.

OBJECTIVE The objective was to establish normative data for hip strength, flexibility, and stiffness in male soccer athletes and to investigate the effect of age and limb dominance on these variables. DESIGN Cross-sectional. SETTING Soccer team physical therapy department. PARTICIPANTS A total of 293 asymptomatic male soccer athletes were assessed. Elite youth players aged 15-17 years and professional adult players aged 18-29 years old. MAIN OUTCOME MEASURES Rectus femoris, iliopsoas, hamstring muscle flexibility, passive hip stiffness, and isometric hip strength were measured using a goniometer, inclinometer, and handheld dynamometer, respectively. Descriptive and mixed analyses of variance were used as statistical procedures. RESULTS The dominant limb had lower iliopsoas (P = 0.010) and rectus femoris (P = 0.003) flexibility and higher external rotators torque compared to the non-dominant limb (P = 0.006) in both age groups. In adult athletes, the dominant limb had lower hip stiffness than the non-dominant limb (P = 0.002). Adults had higher hip external rotator torque than younger athletes (P < 0.0001). No differences were observed for hamstrings flexibility and hip extensors torque. CONCLUSION This study provided normative data of hip strength, flexibility, and stiffness for youth and adult male soccer athletes. In addition, there were no clinically relevant inter-limb differences.