The kinematic feature of Chinese wheelchair racers

The purpose of this study was to investigate the kinematic features of the elite Chinese wheelchair racers to provide some guiding information for their daily training. Participants were divided into three groups. Group I included seven (five males and two females) elite wheelchair racers from Chinese National Team. Group II included two (male) wheelchair racers from Hong Kong. Group III was comprised of two 10-12 years old youth wheelchair racers from Hong Kong after school wheelchair racing training program. Their all-out speed of wheelchair propulsion on a training roller system was filmed by three Basler cameras at 60 Hz with Fire-I software from the sagittal view, front view and oblique view. A standard wheelchair training roller system was used. A 2-D MaxTRAQ software was employed to digitize the wheelchair propulsive movements automatically. Seven reflective markers were placed on the right ear, acromion (shoulder), lateral epicondyle of humerus, styloid process of Ulna, 3rd metacarpophalangeal joint, wheel axis and pushrim. Film data was digitized and smoothed before the joint angles, and angular and linear velocities of the upper extremity were calculated. The results demonstrated that the Chinese wheelchair racers had a significantly larger initial contact angle as compared to Hong Kong adult wheelchair racers and Hong Kong youth wheelchair racers. Three crucial elements in wheelchair racing training for Hong Kong wheelchair racers include: the large initial contact angle, the greater range of push-angle, and the short drive phase. The angular velocities and linear velocity increased dramatically at the wrist joint point indicated that greater linear velocity transferring from the upper arm to forearm and then the hand during wheelchair propulsion. The Chinese elite wheelchair racers mainly use semi-circular wheelchair propulsion pattern. Copyright © 2010 ACESS, Asian Council of Exercise & Sports Science.