Energy cost of walking of below-knee amputees having no vascular disease.

Fifteen unilateral below-knee amputees with no preexisting vascular disease were studied during free velocity walking to determine energy expenditure with and without a prosthesis. Expired air was collected, and heart rate and respiratory rate data were telemetered. Mean velocity for the unrestrained walking was 71 m/min, both during ambulation with a prosthesis and during crutch walking (without a prosthesis). Heart rates were within normal ranges during prosthetic walking (106 beats/min), but rose significantly to 135 beats/min for crutch walking. Energy cost also rose significantly from a mean of 15.5 ml O2/kg/min with a prosthesis of 22.3 ml O2/kg/min with crutches. The oxygen uptake measured in units of ml O2/kg/m increased when the subjects walked faster or slower than their free cadence. We concluded that the use of the prosthesis should be encouraged and that the amputee should be allowed to choose his natural velocity of walking.