Adaptations in physiology and propulsion techniques during the initial phase of learning manual wheelchair propulsion

The purpose of this study was to analyze adaptations in gross mechanical efficiency and wheelchair propulsion technique in novice able-bodied subjects during the initial phase of learning hand-rim wheelchair propulsion. Nine able-bodied subjects performed three 4-min practice blocks on a wheelchair ergometer. The external power output and velocity of all blocks was, respectively, 0.25 W/kg and 1.11 m/sec. Gross mechanical efficiency, force application, timing, and intercycle variability were measured. No change in gross mechanical efficiency was found. However, a decrease in push frequency occurred, which was accompanied by an increase in work per cycle and a decrease in percentage push time. The increase in work per cycle was associated with a higher peak torque. No changes in intercycle variability were visible over time. The timing variables had already changed during the initial phase of learning manual wheelchair propulsion. However, for other variables, such as force production, gross mechanical efficiency, and intercycle variability, a longer practice period might be necessary to induce a change. The effective force direction seemed to be optimized from the start of the learning process onward.