Hamstring-and-lower-back flexibility is not related to hamstring-and-lower-back injuries in elite female soccer players

Objectives Although muscle flexibility is considered to be a risk factor for hamstring-and-lower back injuries (HLB-injuries) in male soccer players, it is unclear whether this is true for elite female soccer players. Design Prospective observational cohort study. Method One hundred fourteen elite female soccer players were monitored during the 2014-2015 soccer season. Hamstring-and-lower-back flexibility (HLB-flexibility) was assessed using the sit-and-reach test (SRT) and soccer exposure and soccer-related injuries were registered. Poisson regression was used to study the association between HLB-flexibility and HLB-injuries with adjustment for possible confounders. Results Of the 114 players, 46 (40%) reported an HLB-injury (60 hamstring injuries and 20 lower back injuries) during the season, accounting for 22% of all injuries reported. No significant association was found between HLB-flexibility and HLB-injuries (P = .534). Also, after correction for potential confounders (age, weight, height, match exposure, and training exposure), HLB-flexibility was not found to be associated with HLB-injuries ((1.027 (0.989-1.066) (RR 95% CI)), P = .164 unadjusted, and 1.022 (0.987-1.059), P = .217 adjusted). Match exposure was significantly associated with HLB-injuries. When the number of match hours increased by 1, the number of HLB-injuries increased by a factor 1.051. Conclusion HLB-flexibility does not influence the occurrence of HLB-injuries in elite female soccer players.