足圧中心位置と立位姿勢の安定性との関係について

Abstract

It was the purpose of this study to show the relationship between the position of the center of foot pressure (CFP) and the steadiness of standing posture. The trace of the motion of CFP for 20 seconds, while the subject stood on a force plate with the eyes opened and the stance closed, was recorded on chart sheet and its length (L) was calculated electrically. The steadiness was evaluated quantitativelly by the L value. The position of CFP was shown by the ratio from heel regarding foot length as 100%. Twenty atheletes of both sexes, aged from 18 to 24 years, were induced to maintain quiet sianding posture (QSP) repeatedly. The mean values of the range of the position of CFP in QSP were 42.34% to 54.19% in male and 36.61% to 51.80% in female. The L values at any positions in QSP were approximatelly identical. Nine untrained females (U group), five female gymnasts (G group) and five female volleyballers (V group), aged from 19 to 24 years, maintained QSP five times and followed by forward or backward leaning postures with CFP at a given position in foot sole. In QSP no differences in the L value were observed between the three groups. L value was maintained within same constant level in certein limited area (stable area) in foot sole, and beyond which area the steadiness lowered. The stable area of G group and T group were significantly larger than that of U group. In forward and backward leaning postures beyond the stable area the steadinesses of G and V groups were significantly higher than that of U group.