The purpose of this study is to make clear the significance of locus length per unit area (total locus length/ area of sway, L/A) as a parameter of stabilometry. We examined 100 healthy subjects aged 6 to 73 years. The subject stands on a stabilometer with eyes open or closed, and the sway of the center of gravity of the body is recorded for one minute. The pattern and area of sway, total locus length, L/A, Romberg's coefficient and power spectrum are recorded, and the L/A and other parameters are correlated.
1) The L/A with eyes closed was low in those less than 20 years of age, higher at age 20 to 50. After age 60, these were some individual differences.
2) The values of L/A with eyes closed were similar to those with eyes open.
3) The L/A showed a negative correlation with the area of sway and the RMS.
4) The L/A was not related to total locus length or Romberg's coefficient.
5) Subjects with a high L/A had a high density power spectrum at 2-5 Hz.
These findings show that L/A is a parameter of the fine control of standing posture by proprioceptive reflexes. The L/A is useful in the examination of the regulation of stan-ding posture.
