Effect of the Height of a Wheelchair on the Shoulder and Forearm Muscular Activation During Wheelchair Propulsion

Abstract

[Purpose] The activations of the shoulder muscle and forearm muscle were analyzed at different chair heights with reference to the user’s elbow joint flexion angle to provide fundamental kinematic data for the fabrication of wheelchairs suitable for the elderly and the disabled with spinal damage. [Subjects] Participants who met the criteria for this study (n=12). [Methods] Muscular activity was measured during propulsion of a wheelchair with chair heights corresponding to elbow flexion angles of 0, 30, 60 and 90 degrees. To eliminate the effect of muscular fatigue, that might have been caused during wheelchair propulsion. [Results] The biceps brachii, anterior deltoid, pectoralis major, serratus anterior and latissimus dorsi muscle activation showed significant differences. [Conclusion] On the basis of the results of this study, we consider that excessive load on the shoulder muscles should be reduced by producing wheelchairs with adjustable chair heights and by using a wheelchair with consideration for an individual’s body size. Future studies should be conducted on the somatic muscle activation at different on chair heights and on the appropriate chair height for various external environments such as a slopeway.