|
| |
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
First published online May 24, 2004
Journal of Experimental Biology 207, 2277-2288 (2004)
Published by The Company of Biologists 2004
doi: 10.1242/jeb.01006
Mechanical function of two ankle extensors in wild turkeys: shifts from energy production to energy absorption during incline versus decline running
Department of Zoology, Oregon State University, 3029 Cordley Hall, Corvallis, OR 97331, USA
* Author for correspondence (e-mail: gabaldoa{at}science.oregonstate.edu)
Accepted 1 April 2004
We investigated the mechanical function of two ankle extensor muscles, the lateral gastrocnemius (LG) and peroneus longus (PL), in wild turkeys Meleagris gallopavo during steady speed running. We hypothesized that mechanical work output of the LG and PL during running parallels the demand for mechanical work on the body. The turkeys ran on level, inclined (+6°, +12°) and declined (–6°, –12°) treadmills to change the demand for mechanical work. Simultaneous measurements of muscle length (from sonomicrometry) and muscle force (from tendon strain gauges) were used to calculate mechanical work output.
During level running at a speed of 2 m s–1, the LG and PL were both active in stance but produced peak force at different times, at approximately 21% of stance duration for the LG and 70% for the PL. The LG and PL also had different length patterns in stance during level running. The LG underwent little shortening during force production, resulting in negligible net positive work (2.0±0.8 J kg–1). By contrast, the PL produced force across a stretch–shorten cycle in stance and did significant net positive work (4.7±1.6 J kg–1). Work outputs for both the LG and PL were directly proportional to running slope. When we increased the demand for net positive work by running the turkeys on an incline, the LG and PL increased stance net positive work output in direct proportion to slope (P<0.05). Stance net positive work output increased to 7.0±1.3 J kg–1 for the LG and 8.1±2.9 J kg–1 for the PL on the steepest incline. Increases in stance net positive work for the LG and PL were associated with increases in net shortening strain and average shortening velocity, but average force in stance remained constant. The LG and PL muscles were also effective energy absorbers during decline running, when there is demand for net negative work on the body. During decline running at 2 m s–1 on the steepest slope, the LG absorbed 4.6±2.2 J kg–1 of net work in stance and the PL absorbed 2.4±0.9 J kg–1 of net work. Shifts in muscle mechanical function from energy production during incline running to energy absorption during decline running were observed over a range of running speeds from 1–3 m s–1 for both the LG and PL.
Two fundamentally different mechanisms for changing work output were apparent in the mechanical behavior of the LG and PL. The LG simply altered its length pattern; it actively shortened during incline running to produce mechanical energy and actively lengthened during decline running to absorb mechanical energy. The PL changed mechanical function by altering its length pattern and by shifting the timing of force production across its stretch–shorten cycle. During incline running, the PL produced force during late stance shortening for positive work, but during decline running, the timing of force production shifted into early stance, to align with lengthening for negative work. In addition, during decline running, the PL greatly reduced or eliminated late stance shortening, thus reducing the potential for positive work.
Our results show that the changing demands for whole body work during steady speed running are met, at least in part, by an ability of single muscles to shift mechanical function from net energy production to net energy absorption.
Key words: locomotion, bird, avian, lateral gastrocnemius, peroneus longus, work, slope, wild turkey, Meleagris gallopavo
This article has been cited by other articles:
|
|
 |
|
  M. Spanjaard, N. D. Reeves, J. H. van Dieen, V. Baltzopoulos, and C. N. Maganaris Lower-limb biomechanics during stair descent: influence of step-height and body mass J. Exp. Biol., May 1, 2008; 211(9): 1368 - 1375. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. E. Nelson and T. J. Roberts Task-dependent force sharing between muscle synergists during locomotion in turkeys J. Exp. Biol., April 15, 2008; 211(8): 1211 - 1220. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. M. Berg and A. A. Biewener Kinematics and power requirements of ascending and descending flight in the pigeon (Columba livia) J. Exp. Biol., April 1, 2008; 211(7): 1120 - 1130. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. M. Gabaldon, F. E. Nelson, and T. J. Roberts Relative shortening velocity in locomotor muscles: turkey ankle extensors operate at low V/Vmax Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2008; 294(1): R200 - R210. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. J. Ellerby and G. N. Askew Modulation of pectoralis muscle function in budgerigars Melopsitaccus undulatus and zebra finches Taeniopygia guttata in response to changing flight speed J. Exp. Biol., November 1, 2007; 210(21): 3789 - 3797. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. DeVita, J. Helseth, and T. Hortobagyi Muscles do more positive than negative work in human locomotion J. Exp. Biol., October 1, 2007; 210(19): 3361 - 3373. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. T. Richards and A. A. Biewener Modulation of in vivo muscle power output during swimming in the African clawed frog (Xenopus laevis) J. Exp. Biol., September 15, 2007; 210(18): 3147 - 3159. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. A. Biewener and M. A. Daley Unsteady locomotion: integrating muscle function with whole body dynamics and neuromuscular control J. Exp. Biol., September 1, 2007; 210(17): 2949 - 2960. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. J. Roberts, B. K. Higginson, F. E. Nelson, and A. M. Gabaldon Muscle strain is modulated more with running slope than speed in wild turkey knee and hip extensors J. Exp. Biol., July 15, 2007; 210(14): 2510 - 2517. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. F. Hodson-Tole and J. M. Wakeling Variations in motor unit recruitment patterns occur within and between muscles in the running rat (Rattus norvegicus) J. Exp. Biol., July 1, 2007; 210(13): 2333 - 2345. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. P. McGowan, R. V. Baudinette, and A. A. Biewener Modulation of proximal muscle function during level versus incline hopping in tammar wallabies (Macropus eugenii) J. Exp. Biol., April 1, 2007; 210(7): 1255 - 1265. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. A. Lichtwark and A. M. Wilson Interactions between the human gastrocnemius muscle and the Achilles tendon during incline, level and decline locomotion J. Exp. Biol., November 1, 2006; 209(21): 4379 - 4388. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. J. Dutto, D. F. Hoyt, H. M. Clayton, E. A. Cogger, and S. J. Wickler Joint work and power for both the forelimb and hindlimb during trotting in the horse J. Exp. Biol., October 15, 2006; 209(20): 3990 - 3999. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Rubenson, H. T. Henry, P. M. Dimoulas, and R. L. Marsh The cost of running uphill: linking organismal and muscle energy use in guinea fowl (Numida meleagris) J. Exp. Biol., July 1, 2006; 209(13): 2395 - 2408. [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]
|
|
|
|
 |
|
 I. D. Loram, C. N. Maganaris, and M. Lakie Use of ultrasound to make noninvasive in vivo measurement of continuous changes in human muscle contractile length J Appl Physiol, April 1, 2006; 100(4): 1311 - 1323. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. A. Lichtwark and A. M. Wilson Effects of series elasticity and activation conditions on muscle power output and efficiency J. Exp. Biol., August 1, 2005; 208(15): 2845 - 2853. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. P. McGowan, R. V. Baudinette, J. R. Usherwood, and A. A. Biewener The mechanics of jumping versus steady hopping in yellow-footed rock wallabies J. Exp. Biol., July 15, 2005; 208(14): 2741 - 2751. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. J. Roberts and R. A. Belliveau Sources of mechanical power for uphill running in humans J. Exp. Biol., May 15, 2005; 208(10): 1963 - 1970. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. J Ellerby, H. T Henry, J. A Carr, C. I Buchanan, and R. L Marsh Blood flow in guinea fowl Numida meleagris as an indicator of energy expenditure by individual muscles during walking and running J. Physiol., April 15, 2005; 564(2): 631 - 648. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Soman, T. L. Hedrick, and A. A. Biewener Regional patterns of pectoralis fascicle strain in the pigeon Columba livia during level flight J. Exp. Biol., February 15, 2005; 208(4): 771 - 786. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. J. Roberts and J. A. Scales Adjusting muscle function to demand: joint work during acceleration in wild turkeys J. Exp. Biol., November 1, 2004; 207(23): 4165 - 4174. [Abstract] [Full Text] [PDF]
|
|
