Acute physiologic and perceptual responses during three modes of ambulation: walking, axillary crutch walking, and running.

This study compared the acute physiologic responses during three modes of ambulation--walking, axillary crutch walking (ACW), and running. Twelve healthy women volunteered to ambulate for one kilometer at their self-selected speeds for each of the three activities. Before the ACW test, the subjects completed one or two training sessions to familiarize themselves with this mode of ambulation. Standardized instruments were used to monitor the cardiorespiratory variables, and perceptual responses were recorded using the Borg scale for ratings of perceived exertion (RPE). The results indicated that walking was the least stressful of the three activities. Comparisons between ACW and running revealed that although the steady-state heart rate and minute oxygen consumption were significantly higher during running (173.5 vs 168.6 beats/min and 2.05 vs 1.06 L/min for running and ACW, respectively), the net metabolic cost per unit distance traveled was significantly higher during ACW (1.77 vs 1.01 kcal/kg/km) because of the longer time taken to ambulate the one-kilometer distance. The other variables studied--the oxygen pulse, ventilatory equivalent for oxygen, and RPE--also clearly indicated that ACW was the most stressful activity. Based on these limited observations, it is suggested that special precautions be taken when prescribing axillary crutches to women who have significant cardiorespiratory problems but are unaware of them, or to cardiac patients because of their coronary insufficiency.