Effect of repeated hot and cold stimulation for the neck and shoulders on muscle fatigue recovery: a pilot study.

Increased use of electronic devices such as smartphones has led to an increase in neck and shoulder stiffness to the forefront of the public people. It is said that prolonged posture with the head tilted forward causes excessive muscle activity in the head and neck region, resulting in muscle fatigue symptoms such as stiff shoulders. Various bathing methods have been proposed as a means of recovering from muscle stiffness, and in particular, contrast water therapy (CWT) is said to be highly effective in recovering from muscle fatigue. In the present study, we examined the effect of CWT with hot and cold stimulation of the neck and shoulders (CWTNS) on muscle fatigue recovery. As the result, in the CWTNS condition, the effects of vasodilation and vasoconstriction were observed, and muscle hardness was significantly lower than that in the Control condition in 20 subjects (2 males, 18 females). Stress hormones were also decreased during and after bathing compared to those before bathing. These results motivate further exploration of the possibility that the effects of CWTNS could be muscle-recovery without high stress load.