Abstract
The lower trunk muscle is involved in stabilizing the action of the standing position, and activation of the muscles of the hip joint is generated by activation of the trunk muscle. The purpose of this study was to clarify whether activation training of the obliquus internus abdominis muscle affects activation of the lower trunk muscle and hip joint abductor muscle action in the standing position. The subject was an elderly healthy man. The muscular activity of the lower trunk muscle in changing from two-leg standing to one-leg standing was compared before and after the training which mainly activated the obliquus internus abdominis muscle. Both % integrated electromyography and coefficient of variation of the obliquus internus abdominis muscle decreased significantly after the training and so did % integrated electromyography of the multifidus muscle. In the gluteus medius muscle, there was no change in % integrated electromyography and the coefficient of variation before and after the training. These results suggest that the training method may prove useful in activating a series of smooth activities of the lower trunk muscle.
