title: Applied physiology for wheelchair design.
abstract: The purpose of this study was to evaluate potential wheelchair design changes that may reduce operational energy cost and cardiopulmonary responses. Design changes, which were simulated with a wheelchair ergometer, allowed two techniques of hand-rim propulsion: the usual synchronous application of force (sync), and an asynchronous technique where force was applied one hand at a time in a reciprocal fashion (async). Three hand-rim drive ratios were also simulated: low, normal, and high. Combinations of these force application-drive ratio simulations were evaluated at power output (PO) levels of 30 and 60 kpm.min-1. The async-high combination was found to elicit significantly lower (P less than 0.01) gross caloric output, pulmonary ventilation, and heart rate values, and provide the greatest advantage over conventional sync-normal operation at both PO levels. It appeared that async propulsion and high drive ratio resulted in less wasted movements. Although the async-high combination was superior under these test conditions, other combinations may be necessary to better match various locomotive tasks to individuals of different capabilities.
mesh_terms: D000328:Adult; D004734:Energy Metabolism; D006804:Ergonomics; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D012119:Respiration; D014910:Wheelchairs / Q000592:standards*