Comparing handrim biomechanics for treadmill and overground wheelchair propulsion.

Study Design: Cross-sectional study.

Objectives: To compare handrim biomechanics recorded during overground propulsion with those recorded during propulsion on a motor-driven treadmill.

Setting: Biomechanics laboratory.

Methods: In all, 28 manual wheelchair users propelled their own wheelchairs, at a self-selected speed, on a low-pile carpet and on a wheelchair accessible treadmill. Handrim biomechanics were recorded with an OptiPush instrumented wheelchair wheel.

Results: Across the two conditions, all handrim biomechanics were found to be similar and highly correlated (r>0.85). Contact angle, peak force, average force and peak axle moment differed by 1.6% or less across the two conditions. Although not significant, power output and cadence tended to be slightly higher for the treadmill condition (3.5 and 3.6%, respectively), owing to limitations in adjusting the treadmill grade.

Conclusion: Based on the results of this study, a motor-driven treadmill can serve as a valid surrogate for overground studies of wheelchair propulsion.