Effectiveness of superficial (hot-pack) and deep (microwave diathermy) heating as a pretreatment for muscle stretching

Abstract

[Purpose] The purpose of this study was to investigate the effectiveness of superficial (hot-pack: HP) and deep (microwave diathermy: MW) heating as a pretreatment for muscle stretching. [Subjects and Method] Sixteen healthy volunteers participated in this study. They received three 20-minute interventions for the bilateral posterior thighs: HP, MW, and rest with neither HP nor MW (control). Hamstrings muscle hardness, the degree of active-knee-extension and the skin temperature of the posterior thigh were compared among the three interventions. [Result] There were no significant differences in hamstrings muscle hardnesses among the three interventions. In contrast, both the degree of active-knee-extension and skin temperature of the posterior thigh after HP and MW were significantly higher than those of the control, but there were no significant differences in the two items between HP and MW. [Conclusion] These results suggest HP and MW may serve as a pretreatment for muscle stretching by reducing stretch pain due to heat stimulation of the skin rather than improving muscle extensibility.