Background Groin pain is common in sports. More insight in risk factors is important to prevent groin injuries.

Objective To examine potential risk factors for groin injuries.

Design Prospective cohort study.

Setting Project focusing on prevention and rehabilitation of groin injuries in elite male soccer players.

Participants Teams of the first and second division in the Netherlands were invited to participate. The final cohort consisted of 238 players from 10 teams.

Assessment of risk factors During the 2015-preseason the soccer players were examined through a baseline questionnaire on player characteristics and complaints (including Hip And Groin Outcome Score, HAGOS), and a clinical examination of the hip/groin (including several Range of Motion (ROM) tests and eccentric strength tests).

Main outcome measurements The dependent variable is the occurrence of a groin injury. The hypothesis is that intrinsic risk factors, like previous (groin) injuries, hip/groin complaints, low hip ROM, and low hip muscle strength, are associated with increased risk of groin injuries. Logistic regression analyses were used to analyse the relationship between the occurrence of a groin injury and potential risk factors.

Results In total, 28 groin injuries were reported, affecting 21 players. The incidence of groin injuries was 0.14 injuries per 1000 training hours (95% CI 0.06–0.31), and 2.41 injuries per 1000 match hours (95% CI 1.30–4.48). There were 6 minor injuries (time-loss <7 days), 7 moderate injuries (8–28 days) and 8 severe injuries (>28 days). In a multivariate model only injury history (moderate/severe injury during the previous season) was significantly associated with increased risk of groin injuries (OR=3.11, 95% CI 1.20–8.09, p=0.02). A multivariate analysis without minor injuries revealed no significant risk factors.

Conclusion Injury history is a significant risk factor for groin injuries: players with an injury lasting at least one week previous season have a three times higher injury risk.