To assess power output, force application, and kinematics of wheelchair propulsion in peak exercise, nine wheelchair athletes with medical lesion levels of T8 or lower performed a 30-s sprint test on a stationary wheelchair ergometer. Mean power output, calculated for the right wheel only, was 59.4 ± 8.5 W. The ratio between effective force and total propulsive force was 60 ± 6%. A negative torque around the hand and a not tangentially directed total force accounted for this low effectiveness. Since the subject group was highly trained, their technique was considered to be optimal for the given circumstances. Therefore, athletes who want to improve power output by increasing effectiveness should keep in mind the existence of a nontangential propulsive force and a braking torque applied by the hands onto the hand rim surface. It is likely that both aspects will be influenced by the geometry of the wheelchair, for example, hand rim dimension or seat position.
Karin Roeleveld, Eric Lute, and Dirkjan Veeger are with the Department of Functional Anatomy and Luc van der Woude is with the Department of Health Sciences, Faculty of Human Movement Science, Vrije Universiteit Amsterdam, v.d. Boechorststraat 9, 1081 BT Amsterdam, The Netherlands. Tom Gwinn is with the Rehabilitation Research Centre, Faculty of Health Science, University of Sydney, P.O. Box 170, Lidcombe NSW 2141, Australia.