正常人の直立時重心動揺の周波数分析 Ｉ 視覚・足底支持面の影響

Abstract

The normal standing posture was evaluated by means of the Fourier analysis of the movement of the center of gravity in 20 normal subjects standing erect.Power spectra of the movement of the center of gravity were transformed to root values. Percentages of the summed root values in each freguency range against the total value were compared in several standing postures.The results obtained in this study are as follows: 1. In Romberg's posture, the value in the frequency range less than 0.5 Hz was about 50% in the left-right (X) direction and about 55% in the anteriorposterior (Y) direction both with eyes open and with eyes closed.Decreases in the value in the ranges from 4 to 5 Hz and from 5 to 10 Hz in the "X" direction and increases in the value in the ranges from 0.5 to 1 Hz and from 1 to 2 Hz and decreases in the value in the ranges from 4 to 5 Hz and from 5 to 10 Hz in the "Y" direction under the condition of eyes closed in comparison with eyes open were statistically confirmed.2. The values in the frequency range from 2 to 3 Hz increased and in the range from 5 to 10 Hz decreased in the "X" direction and the values in the range less than 0.5 Hz decreased and the values in the ranges from 0.5 to 1 Hz, 1 to 2 Hz, 2 to 3 Hz, and 3 to 4 Hz increased in the "Y" direction when the subject was asked to change his standing of Romberg's posture to Mann's posture with his eyes open.However, the difference between the values in Romberg's posture and in one foot standing in both "X" and "Y" directions was the same as the difference between the value in Romberg's posture and in Mann's posture in the "Y" direction.No difference was obtained between standing on one foot on the left leg and on the right.