Does a bounding exercise program prevent hamstring injuries in adult male soccer players? - A cluster-RCT.

BACKGROUND: Although the Nordic Hamstring Exercise (NHE) prevents hamstring injury in soccer players effectively, the annual incidence of these injuries still increases. This may be because of poor long-term compliance with the program. Furthermore, the timing and amplitude of gluteal and core muscle activation seem to play an important role in hamstring injury prevention, the NHE program was not designed to improve activation of these muscles. Therefore, we propose plyometric training as an alternative to reduce hamstring injuries in soccer players. PURPOSE: To determine the preventive effect of the Bounding Exercise Program (BEP) on hamstring injury incidence and severity in adult male amateur soccer players. STUDY DESIGN: A cluster-Randomized Controlled Trial. METHODS: Thirty-two soccer teams competing in the first-class amateur league were cluster-randomized into the intervention or control group. Both groups were instructed to perform their regular training program, and the intervention group additionally performed BEP. Information about player characteristics was gathered at baseline and exposure, hamstring injuries and BEP compliance were weekly registered during one season (2016-2017). RESULTS: The data of 400 players were analyzed. In total, 57 players sustained 65 hamstring injuries. The injury incidence was 1.12/1000 hours in the intervention group and 1.39/1000 hours in the control group. There were no statistically significant differences in hamstring injury incidence (OR = 0.89, 95% CI 0.46-1.75) or severity between the groups (P > 0.48). CONCLUSION: In this large cluster-randomized controlled trial, no evidence was found for plyometric training in its current form to reduce hamstring injuries in amateur soccer players.