DYNAMIC BALANCE TESTING WITH ELECTRICALLY-EVOKED PERTURBATION - A TEST OF RELIABILITY

Objective: To investigate the reliability of a newly developed perturb ation protocol for assessing dynamic balance. Design: Each subject was tested in two experimental balance conditions, static and dynamic. Th e dependent variables for the static condition were sway area (SA), sw ay path length (SPL), sagittal sway standard deviation (SSD), and late ral sway standard deviation (LaSD). During the dynamic condition trial s a stimulus was delivered to the tibial nerves of both legs to pertur b the subjects. The subjects were instructed to return to the pre pert urbation level of steadiness as soon as possible after the stimulation . The dependent variables for the dynamic condition were dynamic phase duration (DPD), sway path mean (SPM), linear sway standard deviation (LiSD), and sagittal sway standard deviation (SSD). Setting: The motor control laboratory of a university department of kinesiology. Patient s: Ten subjects from a population-based sample of healthy adults. Main Outcome Measure: An intraclass reliability estimate for all dependent measures in the static and dynamic conditions. Results: In the static condition, the variables SA, SPL, SSD, and LaSD had reliabilites of . 94, .98, .86, and .92, respectively, and in the dynamic condition the reliability estimates for DPD, SPM, LiSD, and SSD were .90, .71, .80, and .92, respectively. Conclusions: The results indicate the current t echnique provides a means of objectively measuring a subject's ability to regain static postural stability following electrically induced pe rturbation. (C) 1997 by the American Congress of Rehabilitation Medici ne and the American Academy of Physical Medicine and Rehabilitation.