Abstract
To evaluate quantitatively the chronological changes in equilibrium function in elderly persons, we investigated head movement (H. M. ) and movement of the body's center of gravity (M. C. G. ), using a cephalograph to record H. M., a strain-gauge platform to record M. C. G. and a technical computer. Seventy-five healthy subjects aged 30 to 91 years were instructed to stand with feet close together on the platform with eyes open and then with eyes closed for periods of 60 seconds each. The results were as follows:
1) The area and total length of locus traced by H. M. increased with age. Both were significantly greater in subjects older than 50 years of age than in younger adults under 40 years.
2) The area and total length of locus traced by M. C. G. also increased with age. Measurements were significantly greater in subjects older than 70 years of age than in younger adults under 40years.
3) The ratio of the anteroposterior component to the lateral component in H. M. did not differ between the age groups. This ratio for the M. C. G. with eyes open was however, significantly greater in subjects older than 70 years of age than in younger adults.
4) The ratio of the total length of locus traced by H. M. to that of M. C. G. did not differ among the age groups.
5) The ratio of the total length of locus traced by H. M. and M. C. G. with eyes closed to that with eyes open did not differ among the age groups. These results suggest that the body sway of the elderly is not only larger than that of younger adults, but is also fundamentally different in nature.
