APHYSIOLOGIC PERFORMANCE ON DYNAMIC POSTUROGRAPHY

The remarkable ability of the body to maintain balance is the result o f central nervous system integration of sophisticated inputs from the vestibular, visual, and somatosensory systems. Strategies by patients with balance dysfunction are aphysiologic when their performance is re latively better on more difficult conditions of sensory conflict than on easier ones. Twenty-two aphysiologic patterns on computerized dynam ic posturography were compared with age-matched normal and vestibular patterns. The aphysiologic group performed significantly better than t he patients in the vestibular dysfunction group on the most difficult subtests of computerized dynamic posturography, conditions 5 and 6, ye t significantly poorer on the easier subtests, conditions 1 through 4. In addition, patients in the aphysiologic group tended to show greate r intertrial variability compared with patients in both normal and ves tibular system dysfunction groups. A stepwise linear discriminant anal ysis was used to determine a set of conditions that had significant va lue in discriminating between the three patient groups. Case studies a re presented to further illustrate the clinical usefulness of computer ized dynamic posturography testing in the evaluation of patients suspe cted of having a functional component to their on-feet balance problem s.