2005 年 5 巻 p. 103-108
The foot region plays an important role in postural control. It is often observed that improvement of foot and foot joint functions leads to improvement of movements of the lower limbs, pelvis, trunk, and eventually the entire body. We generally use the position of plantar pressure as a parameter for the evaluation of the foot region and foot joints, because the center of plantar pressure (COP) provides important information. In patients with dysfunction in the foot region, COP is often deviated to the big or little toe side during movements, or induction of COP from the little toe side to the big toe side is often difficult. In therapeutic exercise for control of COP in such patients, closed kinetic chain exercise is considered effective. In such exercises, monitoring of the necessary activities of the peripedal muscles caused by changes in COP is important. In this study, we examined the electromyographic integral of the peripedal muscles caused by changes in COP using a ground reaction force plate and electromyography. In the measurement, a surface electromyograph, Mlyosystem 1200 (NORAXON Co.), was used for recording electromyography. For electromyography analysis, MyoResearch (NORAXON Co.) software was used for calculation of the integrated values of the electromyography. A force plate (Anima Co.) was synchronized with the surface electromyograph. Weight loading on the forefoot and hind foot induced characteristic muscular activity patterns of muscles around the foot. For changing COP, muscular activity of muscles around the foot is necessary, and it is important to know that the muscular activity pattern varies depending on the position of COP.