Towards a unified notion of gaits
Animal Abstracts, 2012
Abstract
While a variety of definitions of "gait" have proved useful in experimental biology, there exist many superficially disparate definitions of "gait", both in the literature and among practicing biologists. At times these definitions are contradictory, for example a definition of gait which required a discrete jump in some quantity (as occurs for the walk-trot transition in dogs) could imply that walking and running are indistinct in some birds; yet, these are intuitively different modes of locomotion. Here we propose a unified conception of gait and show how the hierarchical nature of our definition solves this difficulty and highlights important questions in control and in the determinants of locomotion. We propose to define "gait" as "a parametrically related family of non-dimensional kinematic observations of a locomotor behavior which can persist indefinitely". We arrived at this definition by identifying the commonalities between existing definitions, highlighting the utility of distinctions such as the scale free nature of gait metrics, the cyclic nature of most familiar "gaits", and the natural hierarchies of gaits. We show how existing definitions are embedded in ours. Additionally, we highlight the practical utility of our definition in terms of both pedagogy and research. Our definition conceptually clarifies theories of gait by highlighting the relations between gait hierarchies and locomotion model hierarchies. Our approach sharpens the ability to formulate biomechanical research hypotheses about all forms of locomotion in both species-specific and comparative studies. The resulting language can also be used to describe gaits in non-cyclic locomotion.
BibTeX
@conference{daley-2012-SEB,
author = {Daley, M and Revzen, Shai and Wilshin, S D},
title = {Towards a unified notion of gaits},
booktitle = {Animal Abstracts},
year = {2012},
organization = {Society for Experimental Biology}
}