Thirteen normal male college students were studied during unassisted ambulation and nonweight-bearing ambulation with Ortho crutches and axillary crutches to determine energy expenditure. Subjects walked at self-selected velocities. Energy expenditure was determined by analyzing expired air collected by a calorimeter. Heart rate was monitored by telemetry. During the first 2.5 minutes of walking, heart rate and energy expenditure were significantly greater for ambulation with axillary crutches than with Ortho crutches. After 11.5 minutes of walking, no difference in energy cost was found between crutch types; however, heart rate increased significantly (p less than .01) during ambulation with axillary crutches. Differences in energy cost and heart rate were attributed to increased upper extremity work performed when using axillary crutches. We concluded that during nonweight-bearing ambulation for short periods of time or over a short distance, the Ortho crutch is less taxing in terms of energy cost and heart rate demands.