High school male basketball athletes exhibit greater hamstring muscle stiffness than females as assessed with shear wave elastography

Objective The purpose of this study was to characterize lower extremity passive muscle stiffness in a young, healthy, athletic population. It was hypothesized that males would exhibit greater stiffness than females and that hamstring stiffness would increase with increased passive hamstring stretch. Methods Male ( n = 52, age 16.0 ± 1.3 years, height 180.3 ± 7.9 cm, weight 73.1 ± 11.8 kg) and female ( n = 89, age 15.6 ± 1.3 years, height 169.7 ± 8.1 cm, weight 65.2 ± 13.2 kg) high school basketball athletes were recruited for this study. Shear wave elastography (SWE) was used to measure shear wave velocity (m/s) of the biceps femoris muscle at three leg positions (40%, 60%, and 80%) of the maximum passive 90–90 straight-leg raise position for each leg. Hamstring stiffness (kPa) was quantified from the SWE elastogram using custom processing software. Results Hamstring stiffness was significantly greater for males than females at every position on both the dominant and non-dominant limbs ( p