WHEELCHAIR STABILITY - EFFECT OF BODY POSITION

When a wheelchair user reaches and leans, the static stability decreas es in the direction of the lean and increases in the opposite directio n. The purpose of this study was to determine the extent of this effec t. We studied 21 nondisabled subjects in a representative wheelchair, measuring the static forward, rear, and lateral stability on a tilting platform. Reaching and leaning away from the tip added stability, wit h mean increases ranging from 9.1% to 124.3% of the neutral-position v alues, whereas reaching and leaning toward the tip reduced stability, with mean decreases ranging from 25.2% to 52.3% (p<0.0001). The stabil ity range (''away'' minus ''toward'') varied from 52.4% to 149.5%. Rea ching forward had a greater effect on stability than did reaching back or to the side. Wheelchair users with the ability to control their bo dy positions can profoundly affect the stability of their wheelchairs, a factor that should be considered in wheelchair selection and traini ng.