ENERGETICS AND MECHANICS FOR PARTIAL GRAVITY LOCOMOTION

The role of gravitational acceleration on human locomotion is not clea rly understood. It is hypothesized that the mechanics and energetics o f locomotion depend upon the prevailing gravity level. A unique human- rated underwater treadmill and an adjustable ballasting harness were u sed to simulate partial gravity environments. This study has two resea rch aspects, biome chanics and energetics. Vertical forces which are e xerted by subjects on the treadmill-mounted, split-plate force platfor m show that peak vertical force and stride frequency significantly dec rease (p < 0.05) as the gravity level is reduced, while ground contact time is independent of gravity level. A loping gait is employed over a wide range of speeds (similar to 1.5 m/s to similar to 2.3 m/s) sugg esting a change in the mechanics for lunar (1/6 G) and Martian (3/8 G) locomotion. As theory predicts, locomotion energy requirements for pa rtial gravity levels are significantly less than at 1 G (p < 0.05).