HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Free Full Text (PDF) Free Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science 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 ISI Web of Science (7) Citing Articles via Google Scholar Google Scholar Articles by Modica, J. R. Articles by Kram, R. Search for Related Content PubMed PubMed Citation Articles by Modica, J. R. Articles by Kram, R.

Metabolic energy and muscular activity required for leg swing in running

Department of Integrative Physiology, University of Colorado, Boulder, Colorado

Submitted 17 May 2004 ; accepted in final form 28 January 2005

The metabolic cost of leg swing in running is highly controversial. We investigated the cost of initiating and propagating leg swing at a moderate running speed and some of the muscular actions involved. We constructed an external swing assist (ESA) device that applied small anterior pulling forces to each foot during the first part of the swing phase. Subjects ran on a treadmill at 3.0 m/s normally and with ESA forces up to 4% body weight. With the greatest ESA force, net metabolic rate was 20.5% less than during normal running. Thus we infer that the metabolic cost of initiating and propagating leg swing comprises 20% of the net cost of normal running. Even with the greatest ESA, mean electromyograph (mEMG) of the medial gastrocnemius and soleus muscles during later portions of stance phase did not change significantly compared with normal running, indicating that these muscles are not responsible for the initiation of leg swing. However, with ESA, rectus femoris mEMG during the early portions of swing phase was as much as 74% less than during normal running, confirming that it is responsible for the propagation of leg swing.

biomechanics; locomotion; electromyography; energetic cost

This article has been cited by other articles:

				J. L. Bartlett and R. Kram Changing the demand on specific muscle groups affects the walk-run transition speed J. Exp. Biol., April 15, 2008; 211(8): 1281 - 1288. [Abstract] [Full Text] [PDF]

				L. P. J. Teunissen, A. Grabowski, and R. Kram Effects of independently altering body weight and body mass on the metabolic cost of running J. Exp. Biol., December 15, 2007; 210(24): 4418 - 4427. [Abstract] [Full Text] [PDF]

				C. P. McGowan, H. A. Duarte, J. B. Main, and A. A. Biewener Effects of load carrying on metabolic cost and hindlimb muscle dynamics in guinea fowl (Numida meleagris) J Appl Physiol, October 1, 2006; 101(4): 1060 - 1069. [Abstract] [Full Text] [PDF]

				R. L. Marsh, D. J. Ellerby, H. T. Henry, and J. Rubenson The energetic costs of trunk and distal-limb loading during walking and running in guinea fowl Numida meleagris: I. Organismal metabolism and biomechanics J. Exp. Biol., June 1, 2006; 209(11): 2050 - 2063. [Abstract] [Full Text] [PDF]

				D. J. Ellerby and R. L. Marsh The energetic costs of trunk and distal-limb loading during walking and running in guinea fowl Numida meleagris: II. Muscle energy use as indicated by blood flow J. Exp. Biol., June 1, 2006; 209(11): 2064 - 2075. [Abstract] [Full Text] [PDF]

				D. A. Raichlen Effects of limb mass distribution on mechanical power outputs during quadrupedalism J. Exp. Biol., February 15, 2006; 209(4): 633 - 644. [Abstract] [Full Text] [PDF]