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

Objective: To investigate the effect of forearm crutch length on energy cos t in three-point, non-weight-bearing (NWB) ambulation. Design: Double-blind repeated measures design using crutch length as the in dependent variable. Setting: Overland walking circuit at a university campus. Participants: Volunteer, convenience sample of 20 subjects consisting of un iversity students and staff without cardiovascular, respiratory, or orthope dic conditions. Intervention: Subjects used a three-point, NWB gait with forearm crutches s et to length using conventional guidelines, and at 2.5cm above and below th is value. Main Outcome Measures: Oxygen consumption, carbon dioxide production, heart rate, speed of ambulation, and perceived exertion under steady-state condi tions. Results: In terms of oxygen cost, ambulation with crutches set to the lengt h recommended in conventional guidelines was not significantly more energy efficient than ambulation with either the longer or shorter crutches. Using crutches set 2.5cm longer than conventional guidelines produced the lowest respiratory exchange ratio ((V) over dot CO2/(V) over dot O-2) and the low est ratings of perceived exertion. However, none of these differences reach ed statistical significance. Conclusion: Since exact crutch length was not critical in terms of oxygen c ost, walking speed, or perceived exertion during NWB ambulation, the import ance of rigidly adhering to specific guidelines for setting crutch length w as not substantiated in this study. Clinically consideration of patient pre ference regarding crutch length (within 2.5cm) can be advocated.