Article

Manual wheelchair propulsion is associated with overuse injuries of
the shoulder. Reaction force redirection relative to upper extremity segments was
hypothesized as a means to redistribute mechanical load imposed on the upper
extremity without decrements in wheelchair propulsion performance. METHODS: Two
individuals performed wheelchair propulsion under simulated inclined (graded)
conditions using self-selected control strategies. Upper extremity kinematics and
reaction forces applied to the wheel were quantified and used as input into an
experiment-based multi-link inverse dynamics model that incorporates
participant-specific experimental results. Reaction force direction was
systematically modified to determine the mechanical demand imposed on the upper
extremity (elbow and shoulder net joint moments and net joint forces) during
wheelchair propulsion. Results were presented as solution spaces to examine the
upper extremity load distribution characteristics within and between participants
across a range of reaction force directions. FINDINGS: Redirection of the
reaction force relative to the upper extremity segments provides multiple
solutions for redistributing mechanical demand across the elbow and shoulder
without decrements in manual wheelchair propulsion performance. The distribution
of load across RF directions was participant specific and was found to vary with
time during the push phase. INTERPRETATION: Solution spaces provide a mechanical
basis for individualized interventions that aim to maintain function and
redistribute load away from structures at risk for injury (e.g. reduce demand
imposed on shoulder flexors (reduce shoulder net joint moment) or reduce
potential for impingement (reduce shoulder net joint force).
CI - Copyright (c) 2011 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS