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

Abstract

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.

Effect of Wheelchair Seat Height on Shoulder and Forearm Muscle Activities during Wheelchair Propulsion on a Ramp

“…To accommodate this change, the lower the height of a wheelchair is, the more the pectoralis major muscle is activated to increase the propulsion force to supplement trunk flexion while the hip joint is flexed. This is different from the result of Lee et al 3) for propulsion on flat ground with wheelchair seat heights, probably because of the posture which change occurs in propulsion on a ramp.…”

“…Using the method of Lee et al 3) , we analyzed muscular activaties with respect to wheelchair seat height during wheelchair propulsion on a ramp to investigate the ideal wheelchair seat height for propulsion on a ramp.…”

“…There have been a variety of studies of joint movements during wheelchair propulsion 4,5) and suitable wheelchair structure for wheelchair propulsion 3) , but there have not been many studies of wheelchair propulsion on a ramp, a frequent situation confronting disabled people in their daily lives. Most studies have investigated propulsion on flat ground.…”

“…Lee et al 3) noted that during wheelchair propulsion on flat ground, elbow joint flexion of 30° provides propulsion force using the least muscular activation. However, unlike flat ground on a ramp, propulsion is offset by potential energy.…”

“…Lee et al 3) suggested a wheelchair seat height suitable for mobility on flat ground. Applying this methodology we investigated the ideal wheelchair height for propulsion on a ramp with a 1:12 slope.…”