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

First published online December 22, 2003
Journal of Experimental Biology 207, 553-563 (2004)
Published by The Company of Biologists 2004
doi: 10.1242/jeb.00774

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 Willey, J. S. Articles by Earls, K. D. Search for Related Content PubMed PubMed Citation Articles by Willey, J. S. Articles by Earls, K. D. Social Bookmarking                         What's this?

The tale of the tail: limb function and locomotor mechanics in Alligator mississippiensis

Jeffrey S. Willey^1,*, Audrone R. Biknevicius^2,, Stephen M. Reilly¹ and Kathleen D. Earls²

¹ Department of Biological Sciences, Ohio University College of Osteopathic Medicine, Athens, OH 45701, USA
² Department of Biomedical Sciences, Ohio University College of Osteopathic Medicine, Athens, OH 45701, USA

Author for correspondence (e-mail: biknevic{at}ohio.edu)

Accepted 29 October 2003

Crocodilians tow their large muscular tail behind them during terrestrial bouts when they high walk (a walking trot). Analysis of ground reaction forces in the American alligator (Alligator mississippiensis) revealed the consequences of tail-dragging. Individual limb and tail ground reaction force records show that the hindlimbs of Alligator take on a substantial role in body mass support consistent with the more caudal location of its center of mass due to the presence of a particularly heavy tail (representing nearly 28% of total body mass). Furthermore, because the constant drag imposed by the tail is substantial, both fore- and hindlimbs in Alligator have a heightened propulsive role as a means of countering the net braking effect of the tail. Ground reaction forces of the whole body were used to assess how well Alligator was able to utilize mechanical energy-saving mechanisms (inverse pendulum or mass-spring). A high-walking Alligator recovers, on average, about 20% of its mechanical energy by inverse pendulum mechanics. These modest energy recovery levels are likely to be due to a combination of factors that may include low locomotor speed, imprecise coordination of contralateral limbs in the trot, frequent dragging of feet of protracting limbs during swing phase and, possibly, tail dragging.

Key words: locomotion, kinetics, limb function, tail-dragging, ground reaction force, Alligator mississippiensis

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

This article has been cited by other articles:

				P. A. Zani and R. Kram Low metabolic cost of locomotion in ornate box turtles, Terrapene ornata J. Exp. Biol., December 1, 2008; 211(23): 3671 - 3676. [Abstract] [Full Text] [PDF]

				M. T. Butcher, N. R. Espinoza, S. R. Cirilo, and R. W. Blob In vivo strains in the femur of river cooter turtles (Pseudemys concinna) during terrestrial locomotion: tests of force-platform models of loading mechanics J. Exp. Biol., August 1, 2008; 211(15): 2397 - 2407. [Abstract] [Full Text] [PDF]

				M. T. Butcher and R. W. Blob Mechanics of limb bone loading during terrestrial locomotion in river cooter turtles (Pseudemys concinna) J. Exp. Biol., April 15, 2008; 211(8): 1187 - 1202. [Abstract] [Full Text] [PDF]

				E. J. McElroy, K. L. Hickey, and S. M. Reilly The correlated evolution of biomechanics, gait and foraging mode in lizards J. Exp. Biol., April 1, 2008; 211(7): 1029 - 1040. [Abstract] [Full Text] [PDF]

				A. R. Lammers, K. D. Earls, and A. R. Biknevicius Locomotor kinetics and kinematics on inclines and declines in the gray short-tailed opossum Monodelphis domestica J. Exp. Biol., October 15, 2006; 209(20): 4154 - 4166. [Abstract] [Full Text] [PDF]

				S. M Reilly, E. J McElroy, R Andrew Odum, and V. A Hornyak Tuataras and salamanders show that walking and running mechanics are ancient features of tetrapod locomotion Proc R Soc B, June 22, 2006; 273(1593): 1563 - 1568. [Abstract] [Full Text] [PDF]

				S. M. Reilly, J. S. Willey, A. R. Biknevicius, and R. W. Blob Hindlimb function in the alligator: integrating movements, motor patterns, ground reaction forces and bone strain of terrestrial locomotion J. Exp. Biol., March 15, 2005; 208(6): 993 - 1009. [Abstract] [Full Text] [PDF]

				A. R. Lammers and A. R. Biknevicius The biodynamics of arboreal locomotion: the effects of substrate diameter on locomotor kinetics in the gray short-tailed opossum (Monodelphis domestica) J. Exp. Biol., November 15, 2004; 207(24): 4325 - 4336. [Abstract] [Full Text] [PDF]

				T. M. Griffin, R. P. Main, and C. T. Farley Biomechanics of quadrupedal walking: how do four-legged animals achieve inverted pendulum-like movements? J. Exp. Biol., September 15, 2004; 207(20): 3545 - 3558. [Abstract] [Full Text] [PDF]

				D. V. Lee, E. F. Stakebake, R. M. Walter, and D. R. Carrier Effects of mass distribution on the mechanics of level trotting in dogs J. Exp. Biol., April 15, 2004; 207(10): 1715 - 1728. [Abstract] [Full Text] [PDF]