Inhibitory effect of a combination of thermotherapy with exercise therapy on progression of muscle atrophy

Abstract

[Purpose] This study was performed to investigate the inhibitory effect of a short-term thermal load in combination with treadmill running or neuromuscular electrical stimulation on the progression of disuse muscle atrophy and its causative mechanism. [Subjects and Methods] The ankle joints of Wistar rats were fixed at maximum plantar flexion, and the fixation was removed for intervention once a day. The rats were divided into 6 groups for intervention: control, fixation, treadmill running, thermal treadmill running, neuromuscular electrical stimulation, and thermal neuromuscular electrical stimulation groups. [Results] The progression of disuse muscle atrophy was inhibited only in the group given a thermal load before treadmill running. Regarding the atrophy mechanism, the expression of heat shock protein 72, which promotes protein synthesis and repair, was enhanced, while the expression of protein ligase E3, which promotes protein degradation, was inhibited. [Conclusion] These findings suggest that thermotherapy prior to exercise therapy promotes the effect of exercise therapy in patients with disuse muscle atrophy and elderly persons.