The gravic body sway test has been widely used as a body equilibrium test. The locus length, area and other parameters of gravic body sway correspond sufficiently to quantitative evaluation. However, quantitative evaluation is difficult for statokinesigraphy, which is the basis of gravic body sway evaluation. The author searched for a quantitative method to classify this. Consequently, in 1983, three patterns were shown by Wilks' Λ analysis, which is a statistical method, and the graph drawn for the classification was shown as a body sway pattern curve (BSPC). However, it was unknown what pattern of gravic body sway the BSPC consisted of. Thus, by using a simulation model, the author investigated what pattern of gravic body sway locus makes the BSPC shown by the Wilks' Λ analysis method and what gravic body sway locus actually means.
As a result, the following facts were found when the property of the simulation was examined by Wilks' Λ analysis. In the locus of the equal speed, the BSPC is not related to the extent and size. The BSPC changes according to the frequency (speed) of the movement. This means that the interpositional relation of the movement over time changes the BSPC. When the position changes greatly over time and never approaches closely to the original position, the BSPC shows a sharp decline. Such body sway is shown, especially when the movement is multicenter type or similar to it, to have multiple body sway planes for the center of gravity.
From these findings, it was found that since the BSPC indicates the interpositional change of the movement over time, features of the movement to control the posture are shown.
