Hamstring injury prevention: before or after training?
This study indicates that scheduling Nordic hamstring exercises (NHE) before or after football training shows similar outcomes in terms of increasing eccentric strength, but distinct architectural adaptations.
Muscle thickness and pennation angle increased when exercising before training. Performing the exercises after training resulted in a small increase in fascicle length.
Hamstring strains are the most prevalent injury in both amateur and professional footballers. The NHE is widely prescribed as part of hamstring injury prevention schemes and has been shown to reduce injury rates. Despite this, there is still a lack of consensus about when to perform these exercises.
A sample of 42 amateur football players was randomized into a control group, a NHE before-training group and a NHE after-training group. The players were evaluated for biceps femoris thickness, fascicle length and pennation angle and maximum isokinetic torque at 30 deg/ sec at baseline and after a 12-week exercise program.
The authors found that peak eccentric knee flexion torque and biceps femoris maximum muscle activation increased in both NHE groups.
Pennation angle and muscle thickness increased only in the before-training group, while fascicle length increased only in the after-training group.
It is noted, however, that there was a modest compliance with the program, which may limit more definite conclusions.
> From: Lovell et al., Scand J Med Sci Sports 28 (2018-03-07 08:34:03) 658-666 (Epub ahead of print). All rights reserved to John Wiley & Sons, Inc.. Click here for the online summary.