Walking dynamics are symmetric (enough)
Abstract
Many biological phenomena such as locomotion, circadian cycles, and breathing are rhythmic in nature and can be modeled as rhythmic dynamical systems. Dynamical systems modeling often involves neglecting certain characteristics of a physical system as a modeling convenience. For example, human locomotion is frequently treated as symmetric about the sagittal plane. In this work, we test this assumption by examining human walking dynamics around the steady-state (limit-cycle). Here we adapt statistical cross validation in order to examine whether there are statistically significant asymmetries, and even if so, test the consequences of assuming bilateral symmetry anyway. Indeed, we identify significant asymmetries in the dynamics of human walking, but nevertheless show that ignoring these asymmetries results in a more consistent and predictive model. In general, neglecting evident characteristics of a system can be more than a modeling convenience---it can produce a better model.
Cite
@article{arxiv.1407.8541,
title = {Walking dynamics are symmetric (enough)},
author = {M. Mert Ankaralı and Shahin Sefati and Manu S. Madhav and Andrew Long and Amy J. Bastian and Noah J. Cowan},
journal= {arXiv preprint arXiv:1407.8541},
year = {2016}
}
Comments
Draft submitted to Journal of the Royal Society Interface