Abstract

The purpose of this study was to determine the contributions of arm frequency and propulsion mode on the internal work during submaximal wheelchair propulsion. Twelve able-bodied participants performed a VO2 peak test on a wheelchair ergometer. On a separate occasion, six (4 min) submaximal exercise conditions employing two modes of propulsion (synchronous, SYN vs. asynchronous, ASY) at arm frequencies of 40 and 80 rev/min were performed at 1.2m/s and 1.7m/s. These conditions resulted in three push strategy combinations (ASY [20:20], SYN [40:40] and ASY [40:40]) at two speeds. Gross, net, work and delta efficiency were determined. The cost of unloaded exercise was significantly lower for the ASY [20:20] than both ASY and SYN [40:40] (0.49 vs. 0.58 and 0.57 L/min, respectively). All the efficiency indices decreased as velocity increased (p<0.01). ASY [20:20] was the least efficient (gross and work) mode (4.2+/-0.4% and 6.2+/-0.8% respectively). Comparison of equal arm frequencies (ASY [40:40] vs. SYN [40:40]); found the efficiency to be lower for ASY propulsion (p<0.05). Under the current testing conditions SYN propulsion mode offers greater efficiency during wheelchair propulsion. Verf.-Referat