In 1983, the board of the Japan Society for Equilibrium Research presented a standard of stabilometry, but some problems remain.
In order to determine the test conditions, we performed the following examination with a standard stabilometer.
1 . For visual target testing, the distance from the subject to the target and the illumination of the peripheral visual field were studied.
2. For the standing posture, body sway in the military standing posture was compared with that in natural standing.
3. For foot position, body sway while standing with both feet together was compared with that feet in the fan-shaped position and with feet apart but parallel.
4. For recording time, body sway while standing for 30 seconds was compared with that while standing for 60 seconds.
5. To elimilinate transitional sway after standing erect with eyes closed, the time when the recording should start was studied.
The parameters for stabilometry are as follows ; unit locus lengh, forward-backward and right-left diameters, area, rejection ellipse, center of sway, standard deviation, skewness and kurtosis of amplitude probability density distribution, velocity, vector of velocity, power spectrum.
1. When the visual target was placed one meter from the subject and the peripheral field of vision was lighted, the mean and standard deviation of all parameters in stabilometry were the smallest.
2. Standard deviations of the unit locus length, area and velocity during military posture standing were lower than during natural standing. However, maintenance of military standing for 60 seconds was difficult. Therefore, stabilometry with natural standing was considered more suitable for clinical examinations.
3. Body sway while standing with feet 10 cm apart was less than when standing with the feet close together or in the fan-shaped position. However, standing with the feet close together was suitable for detecting slight equilibrium disturbances.
4. Body sway observation for 60 seconds clarified the pattern of the body sway more definitely than did observation for 30 seconds.
5.Irregular sway was recorded after the subject stood erect with eyes closed for 10 seconds. To eliminate transitional sway, the recording should be started when the body movements of the standing subject are stabilized.
