Kinematics of the elbow during wheelchair propulsion: A comparison of two wheelchairs and two stroking techniques

Objective: The kinematics of the elbow joint were studied for two types of wheelchairs and during two types of propulsive strokes. Participants: Ten serially selected healthy volunteers propelled a standard and a lightweight wheelchair on a roller system with both circular and pumping strokes. Design: Kinematic data for the wheelchair and the upper extremity were collected by an optical tracking system. These kinematic descriptors were subsequently time-normalized with a spline algorithm to provide a graphic description of the wheelchair strokes. Main Outcome Measures: Thirteen discrete variables were compared for the two chairs and the two propulsive strokes. Results: Total elbow motion ranged from 60.9°of flexion to 5.2°of extension. Maximal elbow flexion velocity ranged from 515.4°to 572.8°per second. Kinematic differences between the two wheelchairs were minimal, with a trend for 8.3°to 5.2°more elbow flexion in the lightweight wheelchair (p < .05), depending on the stroke used. With the use of any one chair, the style of the stroke had no significant effect on elbow kinematics, but the use of a pumping stroke did decrease propulsion arc by 12°to 14°(p < .05). Conclusion: No major differences regarding elbow kinematics were seen between the two types of wheelchairs. The pumping-stroke technique resulted in a shortened handrim contact arc.