Design principles for a zero-gravity locomotion simulator

The loss of calcium in the bones of the lower extremity remains a major concern in the planning of long term space flight. Exercise while tethered to a treadmill has been proposed as a countermeasure to bone demineralization. The design of the simulator is based on a supine suspension device used in the Soviet space program as a pre-flight training method. By using kinematic data for treadmill running in 1g in a computer simulation, it was determined that the location of the elastic cords at the segmental centers of mass would not interfere with normal movement patterns and that variations in the supporting force on the segments could be maintained within 5%. Based on these and other experiments it appears that by using the zero-gravity locomotion simulator in conjunction with a tethering system it will be possible to quantify aspects of exercise in hypogravity that at present are open to conjecture.