The Apollo Number: space suits, self-support, and the walk-run transition.

ABSTRACT:

Background

How space suits affect the preferred walk-run transition is an open question with relevance to human biomechanics and planetary extravehicular activity. Walking and running energetics differ; in reduced gravity (<0.5 g), running, unlike on Earth, uses less energy per distance than walking.

Methodology/principal findings

The walk-run transition (denoted *) correlates with the Froude Number (Fr = v(2)/gL, velocity v, gravitational acceleration g, leg length L). Human unsuited Fr* is relatively constant (approximately 0.5) with gravity but increases substantially with decreasing gravity below approximately 0.4 g, rising to 0.9 in 1/6 g; space suits appear to lower Fr*. Because of pressure forces, space suits partially (1 g) or completely (lunar-g) support their own w

SUBMITTER: Carr CE 

PROVIDER: S-EPMC2719915 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature