Controllability and physiological evaluation of three unilaterally-propelled wheelchairs for patients with hemiplegia

Objective: To evaluate the controllability of, and physiological responses to, 2 newly designed unilaterally-propelled wheelchairs for patients with hemiplegia. Design: Within-subject comparison. Subjects: A total of 15 patients after stroke were recruited from the rehabilitation centre of Chung Shan Medical University, Taichung, Taiwan. Methods: Two newly designed wheelchairs (an ankle-propelled wheelchair and a knee-propelled wheelchair) were compared with a commercially available 2-hand-rim propelled wheelchair. Patients propelled the 3 wheelchairs along an oval pathway. Videotapes were made for analysis. The following parameters: total propulsion time, deviation frequency, deviation percentage, physiological cost index (VO2) and rating of perceived exertion were measured and compared. Results: The knee-propelled wheelchair gave the best results for controllability, cardiopulmonary and perceived exertion. However, the gear ratio of this wheelchair's force transmission was fixed, and some patients felt that its propulsion was heavy when starting off. Conclusion: The knee-propelled wheelchair showed good controllability and physiological responses for hemiplegic patients. If some details were improved, it would suitable for use by patients with hemiplegia.