Background: Hamstring injuries are common in sprinters. Identifying pre-season risk factors are essential to target injury-prone athletes and develop injury preventive measures.
Objective: To investigate the incidence of hamstring muscle injury in sprinters over an athletic season and to explore the pre-season predictor of this injury.
Design: Prospective cohort study.
Participants: Forty-four sprinters from the Hong Kong Sports Institute, the Hong Kong Amateur Athletic Association and intercollegiate athletic teams were recruited.
Methods: Preseason assessment of hamstring flexibility, concentric and eccentric isokinetic peak torque, peak torque angle and were obtained at the beginning of an athletic season. The athletes were followed over 12 months and were asked to report all injuries resulting from training and competition.
Results: Eight athletes sustained hamstring injuries over the season. The injury rate was 0.87 per 1000 hours of exposure. The incidence of injuries was higher at the beginning of the season with 58.3% injuries occurring at the first 100 hours of exposure. Cox regression analysis revealed that athletes with a decrease in hamstrings:quadriceps ratio of less than 0.60 at angular velocity of 180°/s increases the risk of hamstrings injury by 17 times.
Conclusion: Performing preseason hamstring/quadriceps peak torque ratio assessments may be useful to identify sprinters susceptible to hamstring injury.