QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online January 8, 2007
Journal of Experimental Biology 210, 366-372 (2007)
Published by The Company of Biologists 2007
doi: 10.1242/jeb.02632

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Abourachid, A. Articles by Martin, V. Search for Related Content PubMed PubMed Citation Articles by Abourachid, A. Articles by Martin, V.

Experimental study of coordination patterns during unsteady locomotion in mammals

Anick Abourachid^*, Marc Herbin, Rémi Hackert, Ludovic Maes and Véronique Martin

FRE2696, CNRS, MNHN, Université P6, Col. de France, Muséum National d'Histoire Naturelle, Département Ecologie et Gestion de la Biodiversité, FRE 2696, Pavillon d'Anatomie Comparée, CP 55, 57 rue Cuvier, 75231 Paris cedex 05, France

^* Author for correspondence (e-mail: abourach{at}mnhn.fr)

Accepted 7 November 2006

A framework to study interlimb coordination, which allowed the analysis of all the symmetrical and asymmetrical gaits, was recently proposed. It suggests that gait depends on a common basic pattern controlling the coordination of the forelimbs (fore lag, FL), the coordination of the hindlimbs (hind lag, HL) and the relationship between these two pairs of limbs (pair lag, PL) in an anteroposterior sequence of movement (APS). These three time parameters are sufficient for identifying all steady gaits. We assumed in this work that this same framework could also be used to study non-steady locomotion, particularly the transitions between symmetrical and asymmetrical gaits. Moreover, as the limbs are coordinated in time and also in space during locomotion, we associated three analogous space parameters (fore gap, FG; hind gap, HG and pair gap, PG) to the three time parameters. We studied the interlimb coordination of dogs and cats moving on a runway with a symmetrical gait. In the middle of the runway, the gait was disturbed by an obstacle, and the animal had to change to an asymmetrical coordination to get over it. The time (FL, HL, PL) and space (FG, HG, PG) parameters of each sequence of the trials were calculated. The results demonstrated that the APS method allows quantification of the interlimb coordination during the symmetrical and asymmetrical phases and during the transition between them, in both dogs and cats. The space and time parameters make it possible to link the timing and the spacing of the footfalls, and to quantify the spatiotemporal dimension of gaits in different mammals. The slight differences observed between dogs and cats could reflect their morphological differences. The APS method could thus be used to understand the implication of morphology in interlimb coordination. All these results are consistent with current knowledge in biomechanics and neurobiology, therefore the APS reflects the actual biological functioning of quadrupedal interlimb coordination.

Key words: gait, mammals, interlimb coordination, anteroposterior sequence