Relative Stresses of Wheelchair Activityl

To study relative stresses of wheelchair activity, seven able-bodied subjects' metabolic (oxygen uptake) and cardiopulmonary (heart rate and pulmonary ventilation) responses were determined during wheelchair (arm stroking) and bicycle (leg pedaling) exercise at identical propulsion velocities and work rates. For this, subjects exercised on a combination wheelchair-bicycle ergometer at wheel velocities of 1.17, 2.34, and 3.51 km/hr. The six bouts of exercise were intennittent~5-min exercise periods interspersed by 10-min rest periods. At 1.17 km/hr, no significant differences were found between wheelchair and bicycle exercise for each of the monitored variables. At 2.34 and 3.51 km/hr, however, all responses were significantly higher for wheelchair exercise. At these higher velocities, calculated respiratory exchange ratio and ventilatory equivalent values were also significantly higher for wheelchair exercise. These results suggest that acute exposure to wheelchair activity could be relatively stressful and could limit rehabilitative efforts.