Mechanical load on the upper extremity during wheelchair activities.

Abstract

To determine the net moments on the glenohumeral joint and elbow joint during wheelchair activities. Kinematics and external forces were measured during wheelchair activities of daily living (level propulsion, riding on a slope, weight-relief lifting, reaching, negotiating a curb) and processed in an inverse dynamics biomechanic model. Biomechanics laboratory. Five able-bodied subjects, 8 subjects with paraplegia, and 4 subjects with tetraplegia. Not applicable. Net moments on the glenohumeral joint and elbow joint. Peak shoulder and elbow moments were significantly higher for negotiating a curb and weight-relief lifting than for reaching, level propulsion, and riding on a slope. Overall, the elbow extension moments were significantly lower for subjects with tetraplegia than for those with paraplegia. The net moments during weight-relief lifting and negotiating a curb were high when compared with wheelchair propulsion tasks. Taking the effect of frequency and duration into account, these loads might imply a considerable risk for joint damage in the long term.