Correlation between two clinical balance measures in older adults: functional mobility and sensory organization test.

BACKGROUND Functional mobility of older adults has been shown to correlate with stance stability to various extents. This variability could be due to the difference in the way sensory information is processed in these two types of balance tests. Correlations between functional mobility and stance stability under altered sensory conditions, such as those in the Sensory Organization Test (SOT), are needed to test this possibility. The present study investigated the correlation between the performance of older adults on a newly developed Sensory-Oriented Mobility Assessment Instrument (SOMAI) and on the various sensory conditions of the SOT. METHODS Twenty-seven community-dwelling older adults (76 +/- 7 years) underwent tests of the six SOT conditions and 10 SOMAI mobility maneuvers performed under normal- and focal-vision (peripheral vision eliminated) conditions. Behavioral performance in the two SOMAI conditions and the amounts of postural sway in the six SOT conditions were ranked among the subjects. Correlations of performance rankings on these two tests were analyzed. RESULTS Performance on the two SOMAI conditions significantly correlated with that on the SOT conditions in which accurate visual, vestibular, and somatosensory inputs were all present (p < .05). Performance on the focal-vision SOMAI condition was also significantly correlated with that on the SOT condition in which somatosensory input was unreliable for orientation while visual and vestibular inputs were reliable (p < .05). There were no correlations between the SOMAI performance and performance on the no-vision or unreliable-vision SOT conditions. CONCLUSIONS The ability to use all visual, somatosensory, and vestibular inputs for balance was correlated with functional mobility. The moderate correlations between the performance on the normal-sensory SOT condition and the SOMAI conditions suggest that body systems other than balance senses also contribute to mobility performance.