Will chronic foam rolling improve hamstring flexibility?

Foam rolling is commonly prescribed by coaches and athletic trainers to athletes preceding warm-up or during the cool down. This is done in effort to transiently increase knee extension range of motion or to facilitate recovery after training or competition. Some athletes will even argue that foam rolling enhances their performance. What remains unclear is the effect the foam rolling has on flexibility after chronic treatment. Static stretching has traditionally been the modality of choice to increase range of motion. More recently, some practitioners feel that foam rolling can be more effective.

A new study published ahead of print in the International Journal of Sports Physiology and Performance tested the effectiveness of static stretching alone or static stretching plus foam rolling for facilitating range of motion improvements of the hamstring muscles. Nineteen adult males (~22 years of age) who had reduced hamstring flexibility (bilaterally) were the recruited subjects. Twice daily for 4 weeks, the subjects performed 4 sets of 45 seconds of static stretching on one leg and 4 repetitions of 60 seconds of foam rolling on the hamstring followed up with 4 sets of 45 seconds of static stretching on the other leg. Before and after the intervention, the researchers measured passive range of motion, hamstring stiffness, rate of torque development and maximum voluntary contraction.

The results showed that range of motion, rate of torque development and maximal voluntary contraction all improved following the intervention for both conditions. Additionally, hamstring stiffness toward end range of motion was reduced post intervention for both legs. However, the researchers were unable to detect any significant difference between legs for improvements in any of the above parameters. Static stretching alone was just as effective as static stretching plus foam rolling for inducing functional improvement in the hamstring muscles. This suggests that foam rolling is likely not an effective treatment for improving flexibility over the long term. However, this does not mean that foam rolling is not useful for other purposes.

Reference:

Morton, RW. et al. Self-Myofascial Release Does Not Improve Functional Outcomes in ‘Tight’ Hamstrings. International Journal of Sports Physiology and Performance. Ahead of print.