Stance and Gait Analysis of Apollo Astronauts on the Moon.

INTRODUCTION/AIM: As humans return to the Moon, safe efficient ambulation and fall prevention on the lunar surface are key concerns. The analysis of gait from archived Apollo mission video footage is now possible with pose estimation video analysis software. Thus, this study aims to retrospectively quantify parameters of Apollo astronauts' stance and gait on the Moon.

METHODS

Publicly available National Aeronautics and Space Administration (NASA) footage of astronauts ambulating on the Lunar surface was examined using body pose analysis software. Goniometric lower limb joint/torso angles and width of base of stance and gait were derived. Gait cycle stance phase, swing phase, double support time, and estimated speed of gait were all computed.

RESULTS

Lunar stance was characterized by 13.3 ± 3.6 SD to 14.3 ± 3.9 SD inch base of stance (based on a 6.5 or 7.0 in. shoe width, respectively), 39.3° ± 9.0° hip flexion, 42.2° ± 14.8° knee flexion, and 17.0° ± 7.5° ankle dorsiflexion. Upper torso anterior tilt was 16.4° ± 8.8°. Lunar gait demonstrated 14.0 ± 2.8 SD to 15.1 ± 2.9 SD base of gait, 0.42 ± 0.16 m/s speed of gait, and 15.4 ± 3.3 in. step length with 40% double support time. Stance phase was 69% and swing phase was 31% of the gait cycle.

DISCUSSION: Decreased speed of gait with wide base, short steps, and increased double support time was seen in astronaut gait patterns. This pattern is adopted on Earth to increase stability and prevent falls.