An Examination of Foot Dynamics under Terrestrial and Lunar Gravity

Lunar EVA boots for Artemis missions will feature a rigid thermal plate to withstand extreme temperatures at the Lunar South Pole. On Earth, the Windlass mechanism enhances foot rigidity during gait by dorsiflexing the great toe, aiding efficient movement. However, its role in Lunar ambulation and potential inhibition by a rigid plate remain unclear. This study examined 20 participants (mean age 21.4) walking, running, and skipping under simulated Lunar and Terrestrial gravity. Motion capture data analyzed the Metatarsophalangeal (MTP) range of motion (ROM) and foot arch height (FAH). No significant differences (p > .05) were found between gravity conditions, suggesting Windlass engagement during Lunar ambulation. Findings indicate Lunar EVA boots should allow 13.8° ± 0.5° of flexion for optimal toe-off efficiency. While a rigid thermal plate is necessary, an adaptive insole may support the Windlass mechanism, mitigating potential musculoskeletal risks associated with prolonged EVA use.