Verification of the superiority of radiofrequency irradiation with static stretching over static stretching alone for...

Healthy hamstring muscles are necessary for active living. Hamstring tightness is a widely reported problem among individuals from all levels of society. The effects of combining radiofrequency (RF) therapy with static stretching (SS) on hamstring tightness have not been investigated. Therefore, we aimed to verify the superiority of combining RF and SS over SS alone by comparing their immediate effects on hamstring flexibility.

This randomized controlled study included 33 participants with hamstring tightness. The participants were allocated to the RF (intervention; n = 17) or sham (n = 16) group. The RF group underwent SS simultaneously with RF therapy. The sham group underwent SS with sham RF (powered off). The range of motion (ROM) for knee extension and five muscle properties (tone, stiffness, elasticity, relaxation, and creep) of the lateral and medial hamstrings were measured before and after the intervention.

There was no significant difference in the ROM for knee extension (p = 0.295) between the RF and sham groups. The interaction between group and period (p > 0.05) was not significant for any of the muscle properties of the lateral and medial hamstrings besides lateral hamstring elasticity (p = 0.001).

RF therapy in conjunction with SS for hamstring tightness produced different changes in muscle properties compared with SS alone. However, these changes did not produce differences in the ROM for knee extension.