Legged Locomotion Paradigms on Earth can Teach Humans how to Safely Extend their Progression Speed when Moving on the Moon

Walk (W), run/trot (R/T) and skip/gallop (S/G) represent the universal gait types for bipeds/quadrupeds on Earth. Each type has been extensively studied by both metabolic and biomechanical research. The main characterizing aspect of those gaits resides in the different strategy to save mechanical energy within the body during progression, and consequently to minimize the energy expenditure: pendulum-like exchange between gravitational potential and kinetic energies (W), storage/release of elastic energy in tendons (R/T), and a combination of the two (S/G). Almost 50 years ago, investigators started challenging human locomotion in different gravitational environments (Margaria & Cavagna, 1964) and rightly concluded that on the Moon walking should be possible only at very low speeds, and that 'terrestrial' running would have been mechanically difficult to adopt there. Later on, a general predicting equation for the speed of dynamically equivalent walking in hetero-gravity has been proposed and validated (Minetti 2001a, 2001b). While studying the 3rd locomotor paradigm for humans, 'skipping' was biomechanically analysed in details and found to be particularly suitable for low gravity environments (Minetti 1998). That insight was confirmed by inspection of NASA footage of Apollo missions, where astronauts frequently preferred to skip. We propose to set up a new, more focused study on human skipping (and small quadruped gallop) in simulated hypogravity during parabolic flights. By using a corridor of dynamometric platforms and 3D motion capture we intend to specifically check the predictions about those gaits and investigate the suitability of a custom training program for humans to adapt/enhance/extend their locomotion repertoire on the Lunar environment. Bibliography Margaria R., Cavagna G. Human locomotion in subgravity. Aerospace Med. 35: 1140-1146, 1964. Minetti A. E. The biomechanics of skipping gaits: a third locomotor paradigm? Proc. R. Soc. B 265: 1227-1235, 1998. Minetti A. E. Invariant aspects of human locomotion in different gravitational environments. Acta Astron. 49(3-10): 191-198, 2001. Minetti A. E. Walking on other planets. Nature 409: 467-469, 2001.