Article

PURPOSE: To investigate the consequence on gross mechanical efficiency (GE),
arm frequency and sub-maximal performance, of paced and unpaced practice during
asynchronous hand-rim wheelchair propulsion. METHODS: Twenty-five able-bodied
participants performed five,
4-min exercise bouts at 1.7 m/s, at the freely
chosen frequency (FCF) and four paced arm frequencies of 60, 80, 120 and 140%
FCF. GE, arm frequency and measures of sub-maximal performance were determined.
Participants were assigned to an unpaced (FCF, N = 9), paced (80% FCF, N = 8) or
control (CON, N = 8) no practice group. The FCF and 80% FCF groups received
4-weeks (unpaced and paced, respectively) propulsion practice (three sessions.per
wk, four 4 min/trials; 33-35 W) at 1.7 m/s on a wheelchair ergometer. Following
practice, the pre-testing protocol was repeated.
RESULTS: Mean GE showed a
relative increase in both experimental groups (21 and 17%; FCF and 80% FCF
respectively; p = 0.001) compared to no change in CON
(-1.5%). The FCF arm
frequency decreased in both experimental groups (p = 0.001), with larger changes
evident following FCF practice. CONCLUSION: Four weeks of unpaced or paced
practice had a beneficial effect on GE. This improvement seems to be associated
with a reduction in arm frequency.

Langue : ANGLAIS