Objective: To determine the net moments on the glenohumeral joint and elbow joint during wheelchair activities.
Design: 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.
Setting: Biomechanics laboratory.
Participants: Five able-bodied subjects, 8 subjects with paraplegia, and 4 subjects with tetraplegia.
Interventions: Not applicable.
Main outcome measure: Net moments on the glenohumeral joint and elbow joint.
Results: 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.
Conclusions: 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.