1. American College of Sports Medicine (1986) Guidelines for graded exercise testing and exercise prescription, 3rd edn. Lea and Febiger, Philadelphia, p 32
2. Bidart Y, Maury M (1973) The circulatory behavior in complete chronic paraplegia. Paraplegia 11:1?24
3. Brattgard SO, Grimby G, Hook O (1970) Energy expenditure and heart rate driving a wheelchair ergometer. Scand J Rehabil Med 2:143?148
4. Engel P, Hildebrandt G (1974) Wheelchair design ? technology and physiological aspects. Proc R Soc Med 67:409?413
5. Glaser RM, Sawka MN, Young RE, Suryaprasad A (1979) Metabolic and cardiopulmonary responses to wheelchair and bicycle ergometry. J Appl Physiol 46:1066?1070