4 Pre-season hip/groin strength and ratings of health are associated with prospective injury in professional footballers

Background Hip and groin injuries are a significant cause of time lost from training and competition in elite football. Purpose To explore the association between hip/groin injury in professional footballers and pre-season assessment of 1) hip adductor and abductor strength, and 2) the Copenhagen Hip and Groin Outcome Score (HAGOS). Study Design Prospective cohort. Methods In total, n=204 elite male footballers from ten professional clubs underwent assessments of hip adductor and abductor strength and completed the HAGOS in pre-season. In-season hip/groin injuries were assessed and reported by team medical staff. Data reduction was conducted using principal component analysis. The subsequent factor component for HAGOS, and three factor components for strength and imbalance measures, were entered with age into a multivariate logistic regression model to determine their association with prospectively occurring hip/groin injury. Results Twenty-four players suffered at least one hip/groin injury throughout the 2017–18 competitive season. The principal component for between-limb abduction imbalance (peak strength in the preferred [kicking] limb – non-preferred limb) (ORe0.61, 95% CIe0.40 to 0.92), and the principal component for HAGOS (ORe0.80, 95% CIe0.64 to 0.99) were independently associated with a reduced risk’of future hip/groin injury. Receiver operator curve analysis of the whole model revealed an area under the curve of 0.76. Conclusion These data demonstrate that a lower likelihood of prospective hip/groin injury during the season was associated with a hip abduction imbalance that favoured the preferred kicking limb and higher HAGOS obtained at pre-season.