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Training to prevent strain injury? Contraction mode matters

Date:
April 1, 2016
Source:
American College of Sports Medicine (ACSM)
Summary:
Hamstring injuries are the most common noncontact injury in elite sport. Despite increased research efforts, these injury rates continue to rise. Recent evidence has shown that short muscle fiber lengths can increase the risk of hamstring injury in elite soccer players. This study aimed to see how fascicle lengths change following training interventions of either lengthening or shortening contractions.
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Hamstring injuries are the most common noncontact injury in elite sport. Despite increased research efforts, these injury rates continue to rise. Recent evidence has shown that short muscle fiber lengths can increase the risk of hamstring injury in elite soccer players. This study aimed to see how fascicle lengths change following training interventions of either lengthening or shortening contractions.

Twenty-eight healthy males trained three times per week for six weeks, followed by a reassessment after four weeks off. Those who trained with lengthening contractions saw a rapid (<14 days) increase in fascicle length, with a loss of any gains following the four weeks off at the end. Those who trained with shortening contractions saw a rapid (<14 days) reduction in fascicle length, with no changes following the four week break.

These findings have implications for injury prevention and rehabilitation practices which should consider the contraction mode and the effect of de-training. An example from elite soccer is prescription of a lengthening training intervention (e.g. Nordic Hamstring Exercise) to an athlete.

This works great, unless the athlete stops doing the exercises in-season or goes on holiday at the end of the season.

Then, all of the hard work is for nothing, with significant reductions in muscle fiber length and potential increases in injury risk.


Story Source:

Materials provided by American College of Sports Medicine (ACSM). Note: Content may be edited for style and length.


Journal Reference:

  1. Ryan G. Timmins, Matthew N. Bourne, Anthony J. Shield, Morgan D. Williams, Christian Lorenzen, David A. Opar. Biceps Femoris Architecture and Strength in Athletes with a Previous Anterior Cruciate Ligament Reconstruction. Medicine & Science in Sports & Exercise, 2016; 48 (3): 337 DOI: 10.1249/MSS.0000000000000783

Cite This Page:

American College of Sports Medicine (ACSM). "Training to prevent strain injury? Contraction mode matters." ScienceDaily. ScienceDaily, 1 April 2016. <www.sciencedaily.com/releases/2016/04/160401112315.htm>.
American College of Sports Medicine (ACSM). (2016, April 1). Training to prevent strain injury? Contraction mode matters. ScienceDaily. Retrieved May 23, 2017 from www.sciencedaily.com/releases/2016/04/160401112315.htm
American College of Sports Medicine (ACSM). "Training to prevent strain injury? Contraction mode matters." ScienceDaily. www.sciencedaily.com/releases/2016/04/160401112315.htm (accessed May 23, 2017).

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