Abstract
[Purpose] The purpose of this study was to suggest the proper seat height for wheelchair propulsion on a slope. [Subjects] Participants who met the criteria for this study (n=20). [Methods] Muscular activity was measured while propelling the wheelchair using the chairs of 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, wheelchair propulsion with the four elbow joint angles was randomly performed. EMG electrodes to the attached were pectoralis major, flex carpi radialis, extensor carpi radialis, serratus anterior, anterior deltoid, biceps brachi, triceps and lattisimus dorsi. [Results] The anterior deltoid, pectoralis major, triceps, extensor carpi radialis and flexor carpi radialis muscle activations showed significant differences between each groups. [Conclusion] This study investigated propulsion on a slope, not flat ground, where propulsion force is offset by potential energy. Thus, unlike flat ground, where small muscle activity is sufficient for propulsion, much muscle activation is necessary to stably go up a ramp.Our results show that in climbing a ramp, user stability is likely to be compromised at wheelchair seat heights eliciting elbow flexion of less/greater than 60 degrees.
