Article

OBJECTIVE: To quantify the effects of stabilizing the paralyzed trunk and pelvis
with electrical stimulation on manual wheelchair propulsion. DESIGN: Single-subject design case series with subjects acting as their own concurrent
controls. SETTING: Hospital-based clinical biomechanics laboratory. PARTICIPANTS:
Individuals (N=6; 4 men, 2 women; mean age +/- SD, 46 +/- 10.8y) who were
long-time users (6.1 +/- 3.9y) of implanted neuroprostheses for lower extremity
function and had chronic (8.6 +/- 2.8y) midcervical- or thoracic-level injuries
(C6-T10). INTERVENTIONS: Continuous low-level stimulation to the hip (gluteus
maximus, posterior adductor, or hamstrings) and trunk extensor (lumbar erector
spinae and/or quadratus lumborum) muscles with implanted intramuscular
electrodes. MAIN OUTCOME MEASURES: Pushrim kinetics (peak resultant force,
fraction effective force), kinematics (cadence, stroke length, maximum forward
lean), and peak shoulder moment at preferred speed over 10-m level surface;
speed, pushrim kinetics, and subjective ratings of effort for level 100-m sprints
and up a 30.5-m ramp of approximately 5% grade. RESULTS: Three of 5 subjects
demonstrated reduced peak resultant pushrim forces (P</=.014) and improved
efficiency (P</=.048) with stimulation during self-paced level propulsion. Peak
sagittal shoulder moment remained unchanged in 3 subjects and increased in 2
others (P<.001). Maximal forward trunk lean also increased by 19% to 26% (P<.001)
with stimulation in these 3 subjects. Stroke lengths were unchanged by
stimulation in all subjects, and 2 showed extremely small (5%) but statistically
significant increases in cadence (P</=.021). Performance measures for sprints and
inclines were generally unchanged with stimulation; however, subjects
consistently rated propulsion with stimulation to be easier for both surfaces.
CONCLUSIONS: Stabilizing the pelvis and trunk with low levels of continuous
electrical stimulation to the lumbar trunk and hip extensors can positively
impact the mechanics of manual wheelchair propulsion and reduce both perceived
and physical measures of effort.
CI - Copyright (c) 2013 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.

Langue : ANGLAIS