Can using a foam roller improve hamstring flexibility?
Traditional contract-relax PNF hamstring stretching was compared against self myofascial hamstring foam rolling as a method to improve hamstring flexibility. The authors used the stand-and-reach test to measure hamstring flexibility changes over a four week intervention period.
They reported a statistically significant improvement in the stand-and-reach test for both intervention groups, compared to the control group. There was, however, no difference between the two intervention groups.
Short hamstring muscles have been shown to increase the risk of developing issues such as low back pain and patellofemoral pain, while contract-relax PNF stretching is known to be a reliable and effective way to improve hamstring flexibility. Foam rolling is a popular choice of athletes to try to improve the passive tension and flexibility of muscles. It is proposed that the pressure of the foam roller acts on the Golgi tendon unit, and consequently encourages a reduction in muscle tension.
47 active male subjects were recruited into the study and assigned to either a contract-relax group, a foam rolling group or a control group. They performed 3 sessions a week over a four week period and hamstring length was measured using the stand-and-reach test pre- and post-intervention.
At the end of the four week period both intervention groups were shown to have improved significantly when compared to the control group, but there were no between group differences.
A 4-week period of self foam rolling of the hamstrings has been shown to be as effective for improving hamstring flexibility as conventional contract-relax PNF stretching.
Further research is needed to understand the mechanisms behind the improvements made with the foam rolling technique.
What type of intervention to you favour to improve muscle flexibility?
> From: Junker et al., J Strength Cond Res 29 (2015) 3480-3485. All rights reserved to National Strength and Conditioning Association. Click here for the Pubmed summary.