Abstract
The purpose of this study is to suggest a numerical model for postural control ability variations in children, young adults and the elderlies. Three sensors were attached to the subjects’ bodies at the vertex, the iliospinale and the mid-patellar to measure three-dimensional acceleration at each point while subjects maintained a standing posture for two minutes. Variations in acceleration at the vertex differed among the three age groups. Most children subjects could not maintain the initial position during the trials, whereas the young adult subjects could maintain it. Most elderly subjects could maintain their lateral balance however it was difficult for them to maintain their anteroposterior balance. From the results of acceleration measurement, it is indicated that the scalar of the average acceleration vector at the vertex point could serve as a numerical criterion of postural control ability.
