Arm crank vs handrim wheelchair propulsion: metabolic and cardiopulmonary responses

The handrim propulsion system of most manual wheelchairs has been shown to be inefficient and stressful to the cardiovascular and pulmonary systems. Arm crank propulsion has been suggested to reduce these stresses. In order to compare conventional handrim wheelchair propulsion to arm crank type wheelchair propulsion, 16 volunteers (9 able-bodied, 7 wheelchair-dependent) operated both wheelchairs over level tiled and carpeted test courses at 3km.hr-1. The arm crank propelled wheelchair was operated in 3 gear ratios: low, medium and high. Exercise bouts were 5 minutes in duration. During the final minute of each test, oxygen uptake (VO2), net locomotive energy cost (NLEC), pulmonary ventilation (VE) and heart rate (HR) were monitored. Subjects exhibited significantly lower magnitude of these physiologic responses during arm crank wheelchair propulsion relative to handrim wheelchair propulsion for all gear drive ratios. Average percent differences were 30% and 32% for VO2; 50% and 50% for NLEC; 27% and 34% for VE; and 16% and 19% for HR on the tiled and carpeted test surfaces, respectively. From these data we conclude that arm crank wheelchair propulsion is less strenuous than conventional handrim wheelchair propulsion and that arm crank propulsion systems should be considered as a possible means to improve wheelchair design.