Human Locomotion in Hypogravity: From Basic Research to Clinical Applications

Abstract

We have considerable knowledge about the mechanisms underlying compensation of Earth gravity during locomotion, a knowledge obtained from physiological, biomechanical, modeling, developmental, comparative, and paleoanthropological studies. By contrast, we know much less about locomotion and movement in general under sustained hypogravity. This lack of information poses a serious problem for human space exploration. In a near future humans will walk again on the Moon and for the first time on Mars. It would be important to predict how they will move around, since we know that locomotion and mobility in general may be jeopardized in hypogravity, especially when landing after a prolonged weightlessness of the space flight. The combination of muscle weakness, of wearing a cumbersome spacesuit, and of maladaptive patterns of locomotion in hypogravity significantly increase the risk of falls and injuries. Much of what we currently know about locomotion in hypogravity derives from the video archives of the Apollo missions on the Moon, the experiments performed with parabolic flight or with body weight support on Earth, and the theoretical models. These are the topics of our review, along with the issue of the application of simulated hypogravity in rehabilitation to help patients with deambulation problems. We consider several issues that are common to the field of space science and clinical rehabilitation: the general principles governing locomotion in hypogravity, the methods used to reduce gravity effects on locomotion, the extent to which the resulting behavior is comparable across different methods, the important non-linearities of several locomotor parameters as a function of the gravity reduction, the need to use multiple methods to obtain reliable results, and the need to tailor the methods individually based on the physiology and medical history of each person.

The “Journal of Functional Morphology and Kinesiology” Journal Club Series: PhysioMechanics of Human Locomotion

“…To counteract and contain this phenomenon, worldwide actions aimed to promote specific health prevention interventions. These interventions are addressed to reduce cardiometabolic risk factors, combining a balanced diet with an adequate level of weekly physical activity [ 60 ]. For the above reasons, walking can be performed in different environments with no need of particular equipment, overcoming some common barriers such as the lack of time, low fitness level, and shortage of money.…”

Vitamin D in Space

“…An essential point about Apollo's trip was the ability of humans to perform physical activities in an environment with gravity much lower than on the Earth's surface, equivalent to one-sixth. It is worthy to mention that gravitational force on the surface of Mars is twice that of the Moon and a third of the Earth [10].…”

“…The program ended in 1972. During this program, 12 astronauts traveled to the Moon, which lasted for a few days [10].…”

A new method for the performance of external chest compressions during hypogravity simulation

“…These hypogravity parabolic flights would more accurately represent acute cardiopulmonary system changes in the rescuer and perhaps influence their CPR performance by fully unloading the body, compared to the BSD where the limbs and head are not unloaded. However, all simulations have strengths and weaknesses 20 . The main weakness of parabolic flights is the relatively short duration of hypogravity that they offer, between 25 seconds for 0.17Gz (Moon) and 32 seconds for 0.38Gz (Mars) 20,26 .…”

“…However, all simulations have strengths and weaknesses 20 . The main weakness of parabolic flights is the relatively short duration of hypogravity that they offer, between 25 seconds for 0.17Gz (Moon) and 32 seconds for 0.38Gz (Mars) 20,26 . These bursts of hypogravity do not allow for continuous sets of ECCs to be performed and for certain physiological measurements to be made, such as fatigue or performance of ECCs over time.…”