STABILOMETRIC VALUES OF HUMANS UNDER THE CONDITIONS OF FORWARD AND BACKWARD BENT POSITIONS.

Using stabilometry study the center of pressure (COP) displacement over the horizontal surface and power spectrum characteristics of postural sway in the sagittal and frontal planes (Y and X- oscillations, respectively) during an upright stance (US) and under the conditions of body bents forward and backward (BF and BB, respectively) were investigated in a group of 15 volunteers. The tests were performed under the conditions of opened and closed eyes. It was demonstrated that the power spectrum of sway depended on posture, it was greater under the conditions of body bents than during the upright stance. In all three positions blocking of optical input resulted in an increase in power spectrum as well of Y- and X-oscillations in a number of frequency bands of body sway. A significant dependence on the visual control for the mean value of COP under the conditions of bents backward was also found. Data on changes in the lateral oscillations under the conditions of body bents in the sagittal plane showed the essential role of ankle proprioceptors in the genesis of the lateral oscillations at keeping balance during standing. The comparative analysis of power spectrum characteristics of postural sway in the sagittal and frontal planes under the conditions of opened and closed eyes indicated a significant interaction between proprioceptive and visual afferentation at positions of body bents relative to upright stance.