POSTURAL EQUILIBRIUM DURING CENTRIFUGATION

抄録

The purpose of this study has been to clarify the effects of centrifugation on postural equilibrium in relation to labyrinthine function. Twenty normal adults and 32 cases of various labyrinthine disorders were rotated eccentrically in the Still-Werner chair. The position of the unrestrained head relative to the resultant force was measured with an accelerometer attached to the forehead. In the initial stage of eccentric rotation, incomplete postural adaptation of the head was observed not only in cases with labyrinthine disorders but also in normal subjects. The incomplete adaptation was greater in the case of labyrinthine disorder when the hypo-or nonreactive ear was placed outward. During rotation at constant velocity, however, balance was recovered in almost all cases. The labyrinthine contribution for maintaining posture is considered to be most important only when the resultant force is changing direction.