Upper limb dynamics during manual wheelchair propulsion with different resistances

Abstract

Kinematic and kinetic studies have been reported numerously to estimate the dynamic efforts over upper extremity joints during manual wheelchair propulsion. In this study, Joint angles, EMGs and wheelchair axle torque during manual wheelchair propulsion with different external loads were investigated. Four healthy males were volunteered for this study and their motions were analyzed when they propelled the wheelchair. Three dimensional motion data were collected through the motion capture system and also, the signals from the wheelchair dynamometer and the EMG device were recorded synchronized with the motion system. Shoulder, elbow and wrist joint angles and trunk angle were derived from the motion capture system. Propulsion time was increased as the resistance was increased. The wrist, elbow and shoulder joint angles during the contact phase were not different significantly as the resistance increased. The peak torque of wheelchair axle during propulsion was not different significantly between 10 and 15kg resistance. However, the trunk flexion angle and momentum were observed largely increased when the resistance increased. The increased resistance in wheelchair propulsion could be assumed as the increased slope. When the resistance or slope is high, propulsion torques increased but EMG activities were not increased proportional to the resistance. Propulsion time and recovery speed were increased when the resistance was increased. Moreover, trunk flexion allowed the larger downward momentum and it may enhance the propulsion efficiency. © 2010 International Federation for Medical and Biological Engineering.