This study aimed to identify the impact of a Nordic hamstring exercise (NHE) training program on hamstring injury rates in a professional football (soccer) team over 5 seasons. The impact of compliance to the NHE training program (i.e. low, moderate and high compliance) on hamstring injury rates was also investigated.
During the first and last season, no hamstring injury prevention strategies were utilised, with these two seasons being used as the control group. For the remaining three seasons, the NHE training program was implemented and each athlete’s compliance to the sessions was recorded.
During the first 10 weeks of the seasons in which the intervention was implemented, the NHE training program consisted of varying volumes and intensities, as described by Petersen et al. (2011). Following this, the NHE training program was performed once per week and consisted of 3 sets of 8, 10 and 12 repetitions.
In total, 116 athletes were included in the study across the 5 seasons. Throughout the study period, 40 hamstring injuries occurred, with the incidence rate being 0.95 injuries per 1000 hours of training and match exposure.
Within each season, athletes were categorised into the following groups:
- Low compliance (< 20% of sessions completed)
- Moderate compliance (20-70% of sessions completed)
- High compliance (> 70% of sessions completed).