Crutch length: effect on energy cost and activity intensity in non-weight-bearing ambulation.

Abstract

To investigate the effect of forearm crutch length on energy cost in three-point, non-weight-bearing (NWB) ambulation. Double-blind repeated measures design using crutch length as the independent variable. Overland walking circuit at a university campus. Volunteer, convenience sample of 20 subjects consisting of university students and staff without cardiovascular, respiratory, or orthopedic conditions. Subjects used a three-point, NWB gait with forearm crutches set to length using conventional guidelines, and at 2.5 cm above and below this value. Oxygen consumption, carbon dioxide production, heart rate, speed of ambulation, and perceived exertion under steady-state conditions. In terms of oxygen cost, ambulation with crutches set to the length recommended in conventional guidelines was not significantly more energy efficient than ambulation with either the longer or shorter crutches. Using crutches set 2.5 cm longer than conventional guidelines produced the lowest respiratory exchange ratio (Vco2/Vo2) and the lowest ratings of perceived exertion. However, none of these differences reached statistical significance. Since exact crutch length was not critical in terms of oxygen cost, walking speed, or perceived exertion during NWB ambulation, the importance of rigidly adhering to specific guidelines for setting crutch length was not substantiated in this study. Clinically, consideration of patient preference regarding crutch length (within 2.5 cm) can be advocated.