The purpose of this investigation was two-fold: 1) to compare the metabolic cost (VO2), heart rate (HR), and self-selected speed of ambulation of trans-tibial amputees (TTAs) with those of non-amputee subjects; and 2) to determine whether a correlation exists between either stump length or prosthesis mass and the energy cost of ambulation at the self-selected ambulation pace of TTAs. Subjects were thirty-nine healthy male non-vascular TTAs between the ages of 22 and 75 years (mean ± sd = 47 ± 16). All had regularly used their prosthesis for longer than six months and were independent of assistive ambulation devices. Twenty-one healthy non-amputee males aged 27–47 years (31 ± 6) served as controls. Subjects ambulated at a self-selected pace over an indoor course, with steady-state VO2, HR, and ambulation speed averaged across minutes seven, eight and nine of walking. Results showed that HR and VO2 for TTAs were 16% greater, and the ambulation pace 11% slower than the non-amputee controls. Significant correlations were not observed between stump length or prosthesis mass and the energy cost of ambulation. However, when the TTA subject pool was stratified on the basis of long and short stump length, the former sustained significantly lower steady-state VO2 and HR than the latter while walking at comparable pace. These data indicate that stump length may influence the metabolic cost of ambulation in TTAs.

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Dr. Wenger, one of the authors, explains this article as follows: In 1933, a student from India first stimulated my interest in Yoga. In an experiment on muscular relaxation his performance far exceeded that of any other subject. He explained that he employed a Yogic method which was commonly used in India, and I made a mental note to go to India someday. The note got unburied over twenty years later when I discovered an article by Thérèse Brosse, a French cardiologist who had taken a portable electrocardiograph to India in 1935 and measured a few yogis as they at‐ tempted to control their heart action. One of her published EKG records was amazing. It showed a gradual reduction in heart potentials to near zero. She concluded that the heart could be controlled voluntarily. A review of the literature disclosed similar claims, and other claims off voluntary control over other visceral muscles—none, however, so objectively documented. Claims of fire walking, pit burials of many hours' duration, and needle penetration without bleeding are fairly common. Less common are reports of voluntary control of regurgitation and defecation, of great increases in body heat, and of relaxation of the sphincters of the anus and urethra so that water or other fluids can be sucked into the bowel or bladder with the aid of another practice (uddiyana) that apparently creates negative pressure in the abdomen. Testing these various claims of voluntary control of autonomic functions and recording physiological changes during Yogic meditation were our major purposes in going to India.