spacer gif spacer gif spacer gif spacer gif Propose a Workshop for 2011 spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online November 17, 2005
Journal of Experimental Biology 208, 4377-4389 (2005)
Published by The Company of Biologists 2005
doi: 10.1242/jeb.01902
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Robilliard, J. J.
Right arrow Articles by Wilson, A. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Robilliard, J. J.
Right arrow Articles by Wilson, A. M.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

Prediction of kinetics and kinematics of running animals using an analytical approximation to the planar spring-mass system

Justine J. Robilliard1 and Alan M. Wilson1,2,*

1 Structure and Motion Laboratory, The Royal Veterinary College, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK
2 Centre for Human Performance, University College London, Brockley Hill, Stanmore, Middlesex, HA7 4LP,

* Author for correspondence (e-mail: awilson{at}rvc.ac.uk)

Accepted 28 September 2005

The spring-mass model is often used to describe bouncing gaits. Although at first inspection the mechanical system appears simple, the solution to the motion cannot be derived easily. An analytical solution would provide a fast and intuitive method to determine the kinetic and kinematics of the centre of mass of terrestrial animals during over-ground steady state locomotion. Here, an analytical approximation using sine wave simplifications for the motion is presented. The analytical solution was almost indistinguishable from the numerical solution across initial leg angles of 17.5–30°; percentage differences between the analytical solution and the numerical solution were less than 1% for total mechanical energy, centre of mass position, total limb compression and centre of mass velocity and less than 2% different for resultant limb force and vertical acceleration of the centre of mass. The solution matched the relationship between stance time and speed collected from a trotting racehorse and accurately characterised previously published biological data. This study has shown that a simple analytical solution can predict the kinetics and kinematics of a spring-mass system over the range of biologically relevant sweep angles and horizontal velocities, and could be used to further understanding of limb deployment and gait selection. Using this analytical solution not only the force profile but also the changes in mechanical energy can be calculated from easily observed morphological and kinematic data.

Key words: spring-mass, running, locomotion, force


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?




© The Company of Biologists Ltd 2005