Effect of handrim velocity on mechanical efficiency in wheelchair propulsion.

摘要: To study the effect of tangential speed handrims independent external power output on gross mechanical efficiency (ME), nine able-bodied subjects performed wheelchair exercise tests a stationary ergometer. The ergometer allowed for measurement torque and three-dimensional forces rims velocity rear wheels. experiment comprised two series submaximal against constant outputs (0.25 0.50 W.kg-1) four speeds (0.83, 1.11, 1.39, 1.67 m.s-1), which simulated m.s-1 advantages 0.43-0.87. ME stayed below 10.5% changed inversely with movement handrims. Peak torques right handrim even speed, leading to significant increase in peak output. Energy losses owing braking at beginning end push phase increased but hardly exceeded 5 W. effective force component applied was 71% magnitude total vector dropped up 13% increasing speed. It is suggested that an ineffective direction might (partly) be responsible low decrease relation velocity. This suggestion discussed from number theoretical perspectives. concluded use lower advantage will propulsion efficiency.