Manual wheelchair users have a high risk of injuries to the upper extremities due to the mechanical inefficiency of wheelchair propulsion motion. The kinetic analysis of the upper extremities during manual wheelchair propulsion in various conditions needed to be investigated. We developed and calibrated a wheelchair dynamometer for measuring kinetic parameters during wheelchair propulsion. We utilized the dynamometer to investigate and compare the propulsion torque and power of skilled and unskilled users under four different conditions. Skilled manual wheelchair users generated smaller torques with larger power than unskilled users and reacted alertly and sensitively to changing conditions. We expect that the results of this study may help to quantitatively evaluate the mechanical efficiency of manual wheelchair propulsion.