Comparison of static and dynamic posturography in young and older normal people.

OBJECTIVE: To measure sway velocity during static and dynamic posturography in "normal" older people and to determine which tests best distinguish young from older subjects.

SUBJECTS: A sample of 30 young (18-39 years) and 82 community-dwelling older (> 75 years) subjects who reported normal balance underwent a battery of balance tests.

MEASUREMENTS: Velocity and frequency of sway, Tinetti gait and balance score, self-reported fear of falling and number of falls.

RESULTS: Mean sway velocity and the ratio of high to low frequency sway velocity were significantly increased in older subjects compared with younger subjects for static and dynamic tests with eyes open and with eyes closed. Measures of anterior-posterior sway velocity during angular tilt of the platform with eyes closed best distinguished young from older subjects (almost three-fourths of older subjects had values greater than 2 standard deviations from the young normal mean). Older subjects who reported falls in the past year did not have a significantly higher sway velocity on static or dynamic tests compared with those who did not report falls. However, subjects who reported a fear of falling had significantly higher sway velocity on dynamic tests with eyes closed compared to those who did not report a fear of falling.

CONCLUSIONS: On average, velocity of sway is higher in older subjects compared with younger subjects, and the difference between young and old is greater with dynamic posturography than with static posturography.