Physiological evaluation of a newly designed lever mechanism for wheelchairs.
Lever-propelled wheelchairs have been described as more efficient and less physically demanding than hand-rim-propelled wheelchairs. To evaluate a newly designed lever mechanism (MARC) in both one- and two-arm use, a series of wheelchair exercise tests were performed on a motor-driven treadmill. Eight able-bodied male subjects performed a standard exercise test in the prototype MARC, both in an asynchronic and a synchronic bimanual propelling mode and in an unilateral (left-sided) mode. Subsequently the subjects performed additional exercise tests in a conventional crank-to-rod lever mechanism with unilateral and bimanual propulsion and in a conventional hand rim wheelchair. Analysis of variance was used to study the effect of the different work modes upon power output and cardiorespiratory parameters statistically (p < 0.05). The MARC stood out well in comparison with the conventional lever design. The additional design features which are to be implemented (variable gearing, reverse gear) will make the MARC a useful wheelchair. One-arm wheelchair propulsion is a very strenuous form of locomotion, requiring careful consideration in terms of provision. Mechanical and ergonomic improvements are quite feasible in lever propulsion and may to a certain extent reduce this problem. To improve overall mobility of wheelchair-dependent subjects further, ergonomic and mechanical design improvements are very necessary in lever as well as hand-rim wheelchairs. A combined biomechanical and physiological research approach will help in the definition of design criteria and fitting guidelines.
van der Woude
L H
LH
Faculty of Human Movement Sciences, Vrije Universiteit, Amsterdam, The Netherlands.
Veeger
H E
HE
de Boer
Y
Y
Rozendal
R H
RH
D000328:Adult; D004867:Equipment Design; D006804:Ergonomics; D005069:Evaluation Studies as Topic; D005080:Exercise Test; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008328:Man-Machine Systems; D010101:Oxygen Consumption / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012119:Respiration / Q000502:physiology; D014910:Wheelchairs