The biomechanics of wheelchair propulsion in individuals with and without upper-limb impairment.

We used an instrumented wheelchair ergometer and 3D motion analysis system to collect joint kinematic and temporal data, as well as hand rim and joint kinetics, in 47 manual wheelchair users (MWCUs) (15 with upper-limb impairment and 32 without upper-limb impairment). The group with upper-limb impairment propelled with a higher stroke frequency and reduced hand-rim contact time, and smaller peak joint angles and joint excursion of the wrist, elbow, and shoulder during the contact phase. They also propelled with a reduced power output and reduced hand-rim propulsive and resultant forces, moments, and joint compressive forces. We concluded that these kinematic and kinetic strategies might be a mechanism for allowing MWCUs with upper-limb impairment to remain independent. Additionally, the reduced joint excursion and reduced magnitude of forces may protect them from the development of secondary upper-limb pathologies.