PHYSIOLOGICAL COMPARISON OF FORWARD AND REVERSE WHEELCHAIR PROPULSION

Objectives: Conventional wheelchair propulsion is physiologically dema nding because of the small muscle mass that is used and the low mechan ical efficiency of the movement, Previous research has suggested that a reverse wheeling technique might be more economical than conventiona l forward wheeling. The present study sought to compare the physiologi c demands of forward and reverse wheeling techniques. Design: A repeat ed measures design was used to compare the dependent variables between forward and reverse wheeling techniques in the same subjects. Setting : Human exercise research laboratory. Participants: Ten able-bodied me n. Intervention: Subjects completed graded, discontinuous exercise tes ts on a wheelchair ergometer, using both forward and reverse wheeling techniques. Main Outcome Measures: Oxygen uptake ((V) over dot o(2)), ventilation ((V) over dot(E)), and heart rate were measured during the last 30 seconds of each 3-minute exercise stage. Blood lactate concen tration ([La]) and rating of perceived exertion (RPE) were determined immediately after each stage. Results: Repeated measures analysis of v ariance demonstrated that (V) over dot o(2), (V) over dot(E), heart ra te, [La], and RPE were all significantly greater (p < .05) with revers e wheeling compared with forward wheeling. (V) over dot o(2), values w ith reverse wheeling averaged 9% higher than forward wheeling at ident ical power outputs. Conclusions: Reverse wheelchair propulsion is phys iologically more demanding than conventional forward wheelchair propul sion and does not appear to offer potential for improving the economy of wheelchair propulsion. (C) 1998 by the American Congress of Rehabil itation Medicine and the American Academy of Physical Medicine and Reh abilitation.