title: Eccentric hamstring muscle training can prevent hamstring injuries in soccer players.
abstract: OBJECTIVE
  Does eccentric muscle training of hamstring muscles reduce the rate of hamstring injuries in male soccer players?
  
  
  METHODS
  Cluster randomised, controlled trial with concealed allocation.
  
  
  METHODS
  The 5 top men's soccer divisions in Denmark.
  
  
  METHODS
  First team squad soccer players from teams in the top 5 national soccer divisions were included. Players who joined a team after the start of the trial were excluded. Randomisation of 54 teams allocated 26 to the intervention group and 28 to a control group.
  
  
  METHODS
  Both groups followed their usual training program. In addition, the intervention group completed 27 sessions of the eccentric hamstring muscle training in a 10-week period during the midseason break, and once a week in the second half of the season. The hamstring exercise (the Nordic curl) involves the player using hamstrings to resist forward falling of the trunk from a kneeling position. Players completed 2-3 sets of 5-12 repetitions of the exercise for 1-3 sessions per week.
  
  
  METHODS
  The primary outcome was the number of overall, new, and recurrent acute hamstring injuries during one full soccer season. A hamstring injury was defined as any acute physical complaint in the region of the posterior thigh sustained during a soccer match or training. Recurrence of an injury already reported in the trial period was not included to avoid recording the same injury more than once.
  
  
  RESULTS
  50 teams with 942 players completed the study. At the end of the season, there had been 15 hamstring injuries (12 new, 3 recurrent) in the eccentric hamstring exercise group and 52 injuries (32 new, 20 recurrent) in the control group. The number needed to treat (NNT) to prevent 1 hamstring injury (new or recurrent) was 13 (95% CI 9 to 23). The NNT to prevent 1 new injury was 25 (95% CI 15 to 72) and the NNT for recurrent injury was 3 (95% CI 2 to 6). Apart from short term muscle soreness no adverse events were reported in the exercise group.
  
  
  CONCLUSIONS
  An eccentric strengthening exercise program for the hamstring muscles that can be performed during training can help prevent hamstring injuries in soccer players.
authors.affiliation: Department of Mechanical Engineering, The University of Melbourne, Australia.
authors.forename: Anthony
authors.initials: A
authors.lastname: Schache