Reduced gravity effects on gait coordinative structures.

Humans have stepped on the Lunar surface for less than 80 h of Extravehicular Activity, providing a narrow understanding of Lunar gait patterns. NASA's Human-crewed Artemis missions are quickly approaching; understanding how fractional gravity affects gait patterns will be critical for the Moon's and Mars' long-term habitation. This study examined gait patterns under 1.0 g (Earth), simulated 0.38 g (Martian), and 0.17 g (Lunar). Participants walked and ran on a treadmill supported by ARGOS (Active Response Gravity Offload System), simulating fractional gravity. Vicon motion capture data and principal component analysis software were used to capture and quantify coordinated gait structures. There were found to be significant differences (p < 0.05) in the coordinative gait structures for ambulation between fractional gravity conditions. Additionally, there were significantly higher asymmetric gait components for Lunar conditions. Finally, a skipping coordinative structure was identified within Lunar and Martian running.