Abstract
We measured the hardness of the soleus muscle of male students objectively using a newly designed device. After tiptoe standing, hardness of the muscle elevated and gradually decreased according to a time course. The percent of decreases between soon after and 1 min after tiptoe standing were -10.4% in the non-stretching side and -24.1% in the stretching side. A statistical significance was observed between these values. Passive stretching of the muscle accelerated the time course of recovery from hardening after physical exercise. However, passive stretching did not diminish the hardness of the rest muscle. It is well known that stretching recovers muscle elasticity subjectively or by palpation. In this study we objectively demon-strated that stretching is able to soften the muscle after physical exercise.
