Abstract
In the present research a human stance posture control system and a dynamical model for its action are described. The stance of a subject is based on a number of internal body functions, and is arrived at through the combination of nerve centers connecting receptor organs such as inner ear vestibules, sight and kinesthesia, with effectors such as muscles and bones, and a number of functions such as the peripheral nervous system. Accordingly, a subject's stance can be regarded as a sort of barometer for comprehensively evaluating the entire body. The stability from a control engineering standpoint and the health condition were discussed from the model and several subjects aged from 20 to 60 years old. It was found from experiments that the "fluctuation" of a body swaying was a key factor in evaluating health conditions of a stance posture control system. Further there was no obvious relationship between the stability and the health condition in this system.
