DYNAMIC STABILITY IN THE ELDERLY - IDENTIFYING A POSSIBLE MEASURE

Background. The purpose of this research was to assess the ability of trunk acceleration measures to discriminate between the walking patter ns of elderly individuals with and without stability problems. Methods . Twenty volunteers, aged 65 and over, and 19 younger volunteers, all of whom were free of abnormalities or problems that could affect their gait, were recruited for this study. A triaxial accelerometry system was mounted directly over the spine of the upper trunk. Forty seconds of walking data were collected. Using a heel contact switch to define the beginning of the gait cycle, harmonic analyses of each of the 3 ac celeration measures were performed on 10 strides. The ratio of summed amplitudes of the even and odd harmonics (index of smoothness) was cal culated for each stride and averaged across 10 strides. One-way analys es of variance were used to compare harmonic ratios between groups. Re lationships between variables were tested using a correlation analysis . Results. The scores of individuals with stability problems were show n to be significantly different from the younger controls and the olde r individuals without stability problems for the anterior/posterior an d vertical harmonic ratio and peak acceleration measures. Conclusion. The results from this research demonstrate that trunk acceleration mea sures offer the possibility of being able to identify unstable elderly individuals.