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

First published online March 2, 2007
Journal of Experimental Biology 210, 971-982 (2007)
Published by The Company of Biologists 2007
doi: 10.1242/jeb.02728

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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Chang, Y.-H. Articles by Kram, R. Search for Related Content PubMed PubMed Citation Articles by Chang, Y.-H. Articles by Kram, R. Social Bookmarking                         What's this?

Limitations to maximum running speed on flat curves

Young-Hui Chang^1,* and Rodger Kram²

¹ Comparative Neuromechanics Laboratory, School of Applied Physiology, Georgia Institute of Technology, Atlanta, GA 30332-0356, USA
² Locomotion Laboratory, Department of Integrative Physiology, University of Colorado, Boulder, CO 80309-0354, USA

^* Author for correspondence (e-mail: yh.chang{at}gatech.edu)

Accepted 17 January 2007

Why is maximal running speed reduced on curved paths? The leading explanation proposes that an increase in lateral ground reaction force necessitates a decrease in peak vertical ground reaction force, assuming that maximum leg extension force is the limiting factor. Yet, no studies have directly measured these forces or tested this critical assumption. We measured maximum sprint velocities and ground reaction forces for five male humans sprinting along a straight track and compared them to sprints along circular tracks of 1, 2, 3, 4 and 6 m radii. Circular track sprint trials were performed either with or without a tether that applied centripetal force to the center of mass. Sprinters generated significantly smaller peak resultant ground reaction forces during normal curve sprinting compared to straight sprinting. This provides direct evidence against the idea that maximum leg extension force is always achieved and is the limiting factor. Use of the tether increased sprint speed, but not to expected values. During curve sprinting, the inside leg consistently generated smaller peak forces compared to the outside leg. Several competing biomechanical constraints placed on the stance leg during curve sprinting likely make the inside leg particularly ineffective at generating the ground reaction forces necessary to attain maximum velocities comparable to straight path sprinting. The ability of quadrupeds to redistribute function across multiple stance legs and decouple these multiple constraints may provide a distinct advantage for turning performance.

Key words: turning, maneuverability, curve, sprinting, running, locomotion, biomechanics

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

This article has been cited by other articles:

				A. M. Grabowski, C. P. McGowan, W. J. McDermott, M. T. Beale, R. Kram, and H. M. Herr Running-specific prostheses limit ground-force during sprinting Biol Lett, November 4, 2009; (2009) rsbl.2009.0729v1. [Abstract] [Full Text] [PDF]

				D. L. Jindrich, N. C. Smith, K. Jespers, and A. M. Wilson Mechanics of cutting maneuvers by ostriches (Struthio camelus) J. Exp. Biol., April 15, 2007; 210(8): 1378 - 1390. [Abstract] [Full Text] [PDF]