Preseason Passive Torque Asymmetries in Soccer Players with Hamstring Strain Injury

The purpose of this study was to investigate preseason differences in range of motion and passive torque within (injured and non-injured leg) and between (injured and non-injured groups) collegiate soccer players who did and did not sustain hamstring strain injuries. Collegiate male soccer players (n = 108) participated in this study. Range of motion (straight leg raising and passive knee extension) and passive torque were assessed at the beginning of the preseason. Hamstring strain injuries were defined as any acute posterior thigh pain that occurred in non-contact situations, resulting in the immediate cessation of exercise. Eighty-four players were included in the analysis, and 10 players suffered hamstring strain injuries. There were no significant within-group or between-group differences in the range of motion. There was a significant difference in the passive torque between injured and non-injured legs (p = 0.04). Between-group comparisons of asymmetry revealed no significant differences in range of motion, whereas passive torque asymmetry was significantly greater in the injured group (p < 0.01). The results suggested that preseason passive torque asymmetry may be a potential risk factor for hamstring strain injury in collegiate male soccer players.