Improvements in Match-Related Physical Performance of Professional Soccer Players After the Application of an on-Field Training Program for Hamstring Injury Rehabilitation.

Context: Although there are multiple, validated return-to-play programs following hamstring strain injuries, no studies have evaluated their changes in match performance parameters. Objectives: The aim of this study was twofold as follows: (1) to determine the changes in match-based physical performance parameters in professional soccer players before and after sustaining a hamstring strain injury and undergoing a soccer-specific rehabilitation program and (2) to observe the progress of these performance parameters 6 to 10 weeks after the player returned from injury. Design: Prospective, quasi-experimental longitudinal study. Setting: Soccer playing and training grounds. Participants: Nineteen players suffering a hamstring strain injury from 2 male professional teams playing in the Spanish professional football league (La Liga) were followed during the 2015-2016, 2016-2017, and 2017-2018 seasons. Intervention: Participation in on-field training program following a hamstring injury. Main Outcome Measures: Match global positioning system data were collected in the following stages: prior to injury (PRE), after return to play (RTP), program, and 6 to 10 weeks following RTP (C2). Peak velocities and distances ran at splint velocities showed most likely improvements in C2 versus PRE, and very likely improvements in RTP versus PRE. Results: The distances ran at high and very high intensities, the average velocity, and work-to-rest ratio showed very likely improvements in C2 versus RTP and likely improvements in RTP versus PRE. Likely improvements were observed for all variables in C2 versus RTP. The authors' results showed an improvement of physical performance during competitive match after RTP, compared with PRE. There was a steady progression in the progress, and in 8 months following RTP, there was no injury reported in the players. Conclusions: The current findings may indicate that the hamstring muscle complex not only recovered completely from the injury but could also withstand a greater training and match load reducing the risk of reinjury.