A physiological comparison of forward vs reverse wheelchair ergometry

The purpose of this study was to compare metabolic and cardiopulmonary responses for forward wheelchair ergometry (FOR) and reverse wheelchair ergometry (REV) at equal power outputs (PO) levels. Moderately active able-bodies (N = 21) subjects exercised at 3-min stages at PO levels of 15, 20, 25, and 30 W for each mode of ergometry. Oxygen uptake (VO2), pulmonary ventilation (VE), respiratory exchange ratio (RER), heart rate (HR), percent net mechanical efficiency (ME), revolutions per minute (RPM) and strikes per minute (SPM) were determined at each PO level. With the exception of RER, all the physiological responses (VO2, VE, and HR) were higher for FOR exercise (P < 0.05) than REV exercise. ME increased with PO and was higher (P < 0.05) for REV than FOR at each PO level. SPM values for the REV were lower (P < 0.01) by almost half of that for the FOR exercise, although RPM remained constant between modes during all four stages. In general, these data suggest that reverse wheelchair ergometry is physiologically more efficient than conventional wheelchair ergometry and should be studied further as an alternative method for wheelchair ambulation.