Examination of Effective Body Sway Parameters for Healthy Elderly

This study aimed to examine body sway characteristics and to propose effective body sway parameters for healthy elderly. The subjects were 311 healthy elderly and 380 healthy young adults. None of the subjects had evidence or known history of gait, posture, or skeletal disorders. The center of foot pressure measurement for 1 min was performed in 1 trial Using Anima’s stabilometer G5500. The data sampling frequency was 20 Hz. Thirty parameters with high reliability were selected from 5 domains of distance, area, velocity, power spectrum, and body sway vector. In comparison with the results for young adults, the elderly had markedly larger values of mean path length and root mean square of x-axis, as well as for 5 velocity parameters and 4 vector velocity parameters. In addition, approximately 10% of the data for parameters related to body sway velocity, especially front/back body sway, even in the healthy elderly fell in an abnormal range of values (mean ± 3 SD). In conclusion, the following parameters may be useful to adequately and simply evaluate the body sway characteristics of the elderly: sway size, sway velocity, and from a directional viewpoint, sway size in the right/left direction and sway velocity in the front/back direction.