Pageviews

Wednesday, November 2, 2011

EFFECT OF ECCENTRIC TRAINING ON HAMSTRING INJURIES PREVENTION IN FOOTBALL PLAYERS

As you may know, hamstring muscle injury is the most frequent one in football with its prevalence ranging from 12% to 16% of all injuries. The incidence of this type of injury is 0.5-1.5 per 1000 hours of football match and training. It seems also that the risk of hamstring muscle injury re-occurrence is very high. Indeed, re-injury rate is around 22% within the next 2 months of the first injury.

The majority of the prevention programs concentrate on the eccentric strengthening of the hamstring muscles. The Nordic hamstring exercise is a simple eccentric hamstring strength exercise that is being used in a number of prevention routines. However, there is a limited number of randomized controlled studies examining the effect of eccentric muscle strengthening on hamstring injury rate in football players.

One such study was published in the November issue of the American Journal of Sports Medicine by Dr Petersen and colleagues (Petersen et al., 2011, pages 2296-2303). 942 professional and amateur football players were randomly allocated into 2 groups: the intervention and the control group. The intervention group trained with the Nordic hamstring exercise for 10 weeks whereas the control group followed only the regular team’s training. Eccentric strength training was performed once per week in the first week, 2 times in the 2nd week and 3 times per week for the weeks 3-10. The team coach decided on the time of these exercises in the training session. The mean injury registration period for these players was 318 days.




The Nordic hamstring exercise
  • Start in a kneeling position
  • The partner pushes the lower leg or heels of the exercising player to keep them in contact with the ground
  • The exercising player resists the forward movement of his torso using his hamstring muscles for as long as possible
  • The player uses arms and hands to slow down before contact with the ground
  • Immediately after touching the ground with chest, the athlete pushes with his hands to get back to the starting position


Main findings
  1. A total of 67 acute hamstring injuries were registered with 15 injuries in the intervention and 52 injuries in the control group
  2. Injury rate of new injuries was 60% lower in the eccentric training group compared with the control
  3. Rate of recurrent injuries was reduced by about 85% in the intervention group
  4. No injuries occurred in performing the Nordic hamstring exercise


Take home messages
  • It is possible to reduce the incidence of hamstring muscle injury in professional and amateur football players by supplementing their regular training with a simple exercise that focuses on increasing eccentric hamstring muscle strength.
  • This training must be performed 1-3 times per week for a minimum of 10 weeks. Coaches decide on the time of this exercise in the training session.
  • The Nordic exercise seems to be a safe method for improving muscle-specific strength.


No comments: