Incidence of Hamstring Injury and Analysis of Risk Factors for Reinjury in Japanese Professional Football Players

This study demonstrated that the overall incidence of HMI in male Japanese professional football players was 0.60 (/1000 player-hours), including 2.30 (/1000 player-hours) in games and 0.35 (/1000 player-hours) during training. The rate of recurrence was 30%. In the BF, the injury type classified on magnetic resource imaging was the only factor associated with recurrence. Bleeding around the intramuscular tendon without structural tendon injury was an important factor for predicting the recurrence of BF injuries. Type 1-T injuries should be managed differently from type 1-M injuries.