Validity of Functional Stability Limits as a Measure of Balance in Adults Ages 23–73

Abstract

Functional stability limits have been proposed as a psychometric indicator of balance ability that could be used to incorporate stability constraints into ergonomic task analyses. Decreased functional stability limits are assumed to indicate decreased balance ability. These stability limits have been quantified for a young adult population. However, their validity as a measure of balance ability has not been investigated. The purpose of this study was to investigate the construct validity of functional stability limits as a measure of balance ability by quantifying the relationship between these stability limits and age and other more common measures of stability. As hypothesized, functional stability limits decreased with age, were positively related to performance on the Multi-Directional Reach Test, a valid indicator of fall risk for the elderly, and were negatively related to postural sway. However, the strength of these relationships was only moderate; continued analysis is exploring possible explanations for these results.