Abstract
The purpose of this study was to clarify the time course of the stiffness of the hamstrings, range of motion (ROM), stretch tolerance, and isometric peak torque (IPT) of knee flexor after a 5-min static stretching for hamstrings. In 24 participants, static passive torque, representing resistance to stretch, was also measured using an iso-kinetic dynamometer and decreased after stretching on all of experiments. On three different days, dynamic passive torque (DPT) and IPT were measured before and 10, 20 or 30 min after stretching. As a result, ROM and maximal DPT were significantly increased and also IPT was significantly decreased at 10, 20 and 30 min (P< 0.05, respectively) after stretching. Although the stiffness was significantly decreased at 10 and 20 min after stretching (P< 0.05, respectively), this effect recovered within 30 min. These results showed that the retention time of the effect of stretching on stiffness was shorter than the retention time on ROM, stretch tolerance, and IPT.
