Physical strain and mechanical efficiency in hubcrank and handrim wheelchair propulsion

The physical strain and mechanical efficiency of manual wheelchair propulsion using handrim and hubcrank propelled racing wheelchairs were studied during a submaximal wheelchair exercise test on a stationary roller ergometer. Ten healthly male able-bodied subjects conducted two exercise tests in a random order and measurements of physical strain (oxygen uptake, minute ventilation, respiratory exchange ratio, heart rate) and gross mechanical efficiency were obtained. During the experiment torque data, speed and power output were determined at a sample frequency of 0.1 Hz. Results of the analysis of variance for repeated measures show that the hubcrank propulsion mechanism has a significantly lower physical strain and higher gross mechanical efficiency in comparison with the handrim propulsion mechanism.