SPECTRAL CHARACTERISTICS OF POSTURAL CONTROL IN ELDERLY INDIVIDUALS

Objective: To examine the feasibility of using spectral analysis techn iques to identify potential biomarkers of diminished postural control in elderly individuals. Design: Data from spectral signatures (derived from postural sway) of 21 young adults and 42 elderly individuals cla ssified as ''high'' or ''low'' risk with regard to functional balance capacity were analyzed using Risk Category (3) x Sensory Condition (3) multivariate analyses of variance. Postural control was challenged by varying the visual conditions under which individuals stood on a meas urement platform, Results: Results indicated that measures of central tendency and dispersion of the spectral frequency distribution from me dial-lateral components of sway (but not antero-posterior sway) clearl y differentiated between ''high'' and ''low'' risk elderly, Low risk e lderly were not different from young adults. High risk elderly exhibit ed greater dispersion and lower mean frequency than other groups. Conc lusions: Differences in spectral characteristics of medial-lateral com ponents of sway were more related to risk category than to age. Elderl y persons with high functional balance capacity displayed characterist ics similar to those of young adults, Thus, spectral frequency analysi s techniques may be a clinically useful tool for identifying individua ls potentially at risk of falling. (C) 1997 by the American Congress o f Rehabilitation Medicine and the American Academy of Physical Medicin e and Rehabilitation.