2007 年 56 巻 5 号 p. 481-488
The purpose of this study is to show clearly whether the complexity of the cycle of head fluctuation during walking is influenced with walking speed. Thirty young healthy males and females volunteered as subjects for this study. Subjects walked 40 m, and they were instructed to walk “slowly”, “a little slowly”, “usual speed”, “a little fast” and “fast” depending on their subjectivities. The head fluctuation of the right-and-left direction during a walk was measured by using an accelerometer. In addition, the complexity of the head fluctuation of the right-and-left direction cycle was calculated by utilizing Approximate Entropy (ApEn). After the value of ApEn was standardized at the walking speed, each walking speeds were compared. As a result, the value of ApEn increased at the slowly speed, and decreased with the increases in the walking speed. And the value of ApEn showed plateau or decrease at a little faster than free walking speed. From our results, it thought a possibility that Central Pattern Generator is optimized at the free walking speed. In conclusion, it is clear that walking speed have influenced on the complexity of the walking cycle.