Article

OBJECTIVES: To quantify levels of torso muscular demand during wheelchair ramp
ascent and the ability of a geared wheel to influence trunk muscle activity.
DESIGN: Repeated-measures design. Each participant completed manual wheelchair
ramp ascents for each combination of 4 ramp grades (1:12, 1:10, 1:8, and 1:6) and
3 wheel conditions (in gear, out of gear, and a standard spoked wheel) in a block
randomized order by wheel condition. SETTING: Biomechanics laboratory.
PARTICIPANTS: Healthy novice wheelchair users (N=13; 6 men) from a university
student population. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Peak
electromyographic activity, expressed as a percentage of maximal voluntary
isometric contraction (MVIC) of the abdominals, latissimus dorsi, and erector
spinae during ramp ascent. Temporal location of peak electromyographic activity
(EMG) within a propulsive cycle and integrated electromyographic activity for a
single propulsive cycle. RESULTS: Abdominal peak activity increased 13.9% MVIC
while peak posterior trunk muscle activity increased 4.9% MVIC between the
shallowest and steepest ramp grades (P<.05). The geared wheel prevented increased
peak activity of the rectus abdominis and external oblique (P>.05). Only peak
electromyographic timing of the erector spinae was influenced during the push
phase by increasing ramp slope. CONCLUSIONS: Increased trunk muscular demand as a
result of increasing ramp slope is required to enhance stiffness of the spinal
column and provide a stable base during manual propulsion. Manual wheelchair
users with compromised activity capacity, compromised abdominal muscle strength,
or both, may be able to navigate more difficult terrains while using a geared
wheelchair wheel because of reduced demands from the abdominal musculature in the
geared wheel condition.
CI - Copyright 2010 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.

Langue : ANGLAIS