Vaulting mechanics successfully predict decrease in walk-run transition speed with incline

Hubel, T Y; Usherwood, J R

Abstract

There is an ongoing debate about the reasons underlying gait transition in terrestrial locomotion. In bipedal locomotion, the ‘compass gait’, a reductionist model of inverted pendulum walking, predicts the boundaries of speed and step length within which walking is feasible. The stance of the compass gait is energetically optimal—at walking speeds—owing to the absence of leg compression/extension; completely stiff limbs perform no work during the vaulting phase. Here, we extend theoretical compass gait vaulting to include inclines, and find good agreement with previous observations of changes in walk–run transition speed (approx. 1% per 1% incline). We measured step length and frequency for humans walking either on the level or up a 9.8 per cent incline and report preferred walk–run, walk–compliant-walk and maximum walk–run transition speeds. While the measured ‘preferred’ walk–run transition speed lies consistently below the predicted maximum walking speeds, and ‘actual’ maximum walking speeds are clearly above the predicted values, the onset of compliant walking in level as well as incline walking occurs close to the predicted values. These findings support the view that normal human walking is constrained by the physics of vaulting, but preferred absolute walk–run transition speeds may be influenced by additional factors.

Citation

Hubel, T. Y., & Usherwood, J. R. (2013). Vaulting mechanics successfully predict decrease in walk-run transition speed with incline. Biology Letters, 9(2), https://doi.org/10.1098/rsbl.2012.1121

• Journal Article Type: Article
• Acceptance Date: Dec 17, 2012
• Publication Date: Apr 23, 2013
• Deposit Date: Nov 12, 2014
• Publicly Available Date: Feb 15, 2019
• Journal: Biology Letters
• Print ISSN: 1744-9561
• Publisher: The Royal Society
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Issue: 2
• DOI: https://doi.org/10.1098/rsbl.2012.1121
• Public URL: https://rvc-repository.worktribe.com/output/1409202