Characteristic changes of sway of center of gravity with advancing age

Abstract

The righting reflex to avoid falls is altered with advancing age. The purpose of the present study is to find a good index for representing how the righting reflex is exacerbated with advancing age. Stabilometry for standing subjects who were healthy adults with age younger than 51 (9 M and 11 F, younger group) and equal to or older than 51 (22 M and 8 F, elderly group) were carried out. The stabilometry required the subjects to stand on a stabilometer with fixing their eyes to the screen (1 min) and their eyes closed (the following 1 min). Statokinesigrams resulting from the stabilometry were analyzed by 8 indices. In the 'Eyes opened' state, significant changes in previous indices were not found by a decline in the equilibrial function with advancing age. The proposed index, a total of local sums of forces on chains I, was regarded as the most robust and appropriate index to statokinesigrams for the 'Eyes opened/closed' state. This index was applied to the simulation of the elderly (pseudo-elderly study); the subjects were healthy adults with age of 19 to 29 (5 M and 19 F) and wore apparatuses as glasses, earplugs, and weights in the stabilometry. These indices obtained from the statokinesigrams indicated that pseudo-elderly group was the most stable, and the elderly group was the least.