Physiological response to the ambulatory performance of hand-rim and arm-crank propulsion systems

Two types of propulsion systems-the hand rim (HR) and the arm crank (AQ-are commonly used in wheelchair ambulation. The purpose of this study was to i nvestigate the physiological response of the two propulsion systems under a ctual locomotive condition by the actual users. The energetics of locomotio n manual wheelchair (HR propulsion) and arm-propelled three-wheeled chairs (AC-propelled) at their free chosen speed (FCS) were studied and compared. Thirty-four male subjects with dysfunctioning lower limbs; 17 manual wheelc hair users and 17 arm-propelled three-wheeled chairs regular users voluntee red to participate in the study. Speed (m.min(-1)), oxygen uptake (1.min(-1 )) and heart rate (b.min(-1)) were monitored during steady-state ambulation at FCS for 5 min. Oxygen consumption (VO2, ml.kg(-1)min(-1)), oxygen cost (VO2, ml.kg(-1)m(-1)), net locomotive energy cost (kcal kg(-1)km(-1)) and p hysiological cost index (b.m(-1)) were derived. The FCS of the AC propelled device is remarkably higher than the HR system, and the magnitude of the p hysiological variables of the AC propulsion system was significantly lower (p<0.001) in relation to the HR propulsion system, as revealed from the res ults of t test for two sample means at a significance level p=0.001. It can be inferred from the result that the AC propulsion system could be used fo r long distance rides with a higher speed required for outdoor ambulation a nd that the HR propulsion system is suitable only for indoor use, because o f its excellent maneuverability where short-duration low-velocity ambulatio n is required.