Article

OBJECTIVE: To compare the metabolic cost (oxygen uptake per unit time [V o2
consumption], heart rate, and number of pushes), performance (velocity and
distance traveled), and efficiency (oxygen uptake per distance traveled [Vo2
efficiency]) of propulsion using a novel ergonomic hand drive mechanism (EHDM)
and a conventional manual wheelchair (CMW). DESIGN: Repeated-measures crossover
design. SETTING: Semicircular track. PARTICIPANTS: Adult full-time manual
wheelchair users with spinal cord injuries (N=12; mean age +/- SD, 38.8+/-12.4y;
mean body mass +/- SD, 73.7+/-13.3kg; mean height +/- SD, 173.6+/-11.1cm) who
were medically and functionally stable and at least 6 months postinjury.
INTERVENTION: Participants propelled themselves for 3.5 minutes at a
self-selected pace in a CMW and in the same chair fitted with the EHDM. MAIN
OUTCOME MEASURES: Velocity, distance traveled, number of pushes, V o2
consumption, Vo2 efficiency,
and heart rate were compared by wheelchair condition
for the last 30 seconds of each trial using paired t tests (alpha=.01). RESULTS:
The CMW condition resulted in more distance traveled (33.6+/-10.8m vs
22.4+/-7.8m; P=.001), greater velocity (1.12+/-0.4m/s vs .75+/-.30m/s; P=.001),
and better Vo2 efficiency (.10+/-.03mL.kg(-1).m(-1) vs .15+/-.03mL.kg(-1).m(-1);
P<.001) than the EHDM condition, respectively. No significant differences were
found between the 2 conditions for number of pushes (27.5+/-5.7 vs 25.7+/-5.4;
P=.366), V o2 consumption (6.43+/-1.9mL.kg(-1).min(-1) vs
6.19+/-1.7mL.kg(-1).min(-1); P=.573), or heart rate (100.5+/-14.5 beats per
minute vs 97.4+/-20.2 beats per minute; P=.42). CONCLUSIONS: The results
demonstrate that metabolic costs did not differ significantly; however,
performance and efficiency were sacrificed with the EHDM. Modifications to the
EHDM (eg, addition of gearing) could rectify the performance and efficiency
decrements while maintaining similar metabolic costs.
Although not an ideal
technology, the EHDM can be considered as an alternative mode of mobility by
wheelchair users and rehabilitation specialists.
CI - Copyright (c) 2014 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.

Langue : ANGLAIS