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 degrees of flexion to 5.2 degrees of extension. Maximal elbow flexion velocity ranged from 515.4 degrees to 572.8 degrees per second. Kinematic differences between the two wheelchairs were minimal, with a trend for 8.3 degrees to 5.2 degrees 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 degrees to 14 degrees (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.