EurekaMag
+ Most Popular
Cunninghamia lanceolata plantations in China
Mammalian lairs in paleo ecological studies and palynology
Studies on technological possibilities in utilization of anhydrous milk fat for production of recombined butter-like products
Should right-sided fibroelastomas be operated upon?
Large esophageal lipoma
Apoptosis in the mammalian thymus during normal histogenesis and under various in vitro and in vivo experimental conditions
Poissons characoides nouveaux ou non signales de l'Ilha do Bananal, Bresil
Desensitizing efficacy of Colgate Sensitive Maximum Strength and Fresh Mint Sensodyne dentifrices
Administration of fluid by subcutaneous infusion: revival of a forgotten method
Tundra mosquito control - an impossible dream?
Schizophrenia for primary care providers: how to contribute to the care of a vulnerable patient population
Geochemical pattern analysis; method of describing the Southeastern limestone regional aquifer system
Incidence of low birth weights in a hospital of Mexico City
Tabanidae
Graded management intensity of grassland systems for enhancing floristic diversity
Microbiology and biochemistry of cheese and fermented milk
The ember tetra: a new pygmy characid tetra from the Rio das Mortes, Brazil, Hyphessobrycon amandae sp. n. (Pisces, Characoidei)
Risk factors of contrast-induced nephropathy in patients after coronary artery intervention
Renovation of onsite domestic wastewater in a poorly drained soil
Observations of the propagation velocity and formation mechanism of burst fractures caused by gunshot
Systolic blood pressure in a population of infants in the first year of life: the Brompton study
Haematological studies in rats fed with metanil yellow
Studies on pasteurellosis. I. A new species of Pasteurella encountered in chronic fowl cholera
Dormancy breaking and germination of Acacia salicina Lindl. seeds
therapy of lupus nephritis. a two-year prospective study

Motor control of locomotor hindlimb posture in the American alligator (Alligator mississippiensis)


Motor control of locomotor hindlimb posture in the American alligator (Alligator mississippiensis)



Journal of Experimental Biology 206(Pt 23): 4327-4340



ISSN/ISBN: 0022-0949

PMID: 14581602

DOI: 10.1242/jeb.00688

Crocodilians are unusual among quadrupedal tetrapods in their frequent use of a wide variety of hindlimb postures, ranging from sprawling to a more erect high walk. In this study, we use synchronized kinematic videos and electromyographic recordings to test how the activity patterns of hindlimb muscles in American alligators (Alligator mississippiensis Daudin) differ between sprawling and more upright postures. Previous force platform analyses suggested that upright posture in alligators would require greater activation by hindlimb extensors to counter increases in the flexor moments exerted about joints by the ground reaction force during upright stance. Consistent with these predictions, ankle extensors (gastrocnemius) and knee extensors (femorotibialis internus and iliotibialis 2) exhibit increases in signal intensity during the use of more upright stance. Bone loading data also predicted that activation patterns for hip adductors spanning the length of the femur would not differ between sprawling and more upright posture. Correspondingly, motor patterns of the adductor femoris were not altered as posture became more upright. However, the adductor puboischiofemoralis externus 3, which inserts far proximally on the femur, displays significant increases in burst intensity that could contribute to the greater femoral adduction that is integral to upright posture. In contrast to patterns in alligators, in mammals EMG burst intensity typically decreases during the use of upright posture. This difference in the motor control of limb posture between these taxa may be related to differences in the relative sizes of their feet. Alligator feet are large relative to the hindlimb and, as a result, the ground reaction force shifts farther from the limb joints during upright steps than in mammals, increasing flexor moments at joints and requiring alligator extensor muscles to exert greater forces to keep the limb in equilibrium. However, several alligator hindlimb muscles show no differences in motor pattern between sprawling and upright posture. The wide range of motor pattern modulations between different postures in alligators suggests considerable independence of neural control among the muscles of the alligator hindlimb.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 009915614

Download citation: RISBibTeXText

Related references

Differential limb scaling in the american alligator (Alligator mississippiensis) and its implications for archosaur locomotor evolution. Anatomical Record 292(6): 787-797, 2009

Changes in cardiovascular control mechanisms during the embryonic development of the American alligator, Alligator mississippiensis. American Zoologist 40(6): 985, 2000

Ontogeny of baroreflex control in the American alligator Alligator mississippiensis. Journal of Experimental Biology 206(Pt 16): 2895-2902, 2003

Recruitment of the diaphragmaticus, ischiopubis and other respiratory muscles to control pitch and roll in the American alligator (Alligator mississippiensis). Journal of experimental biology 211(Pt 7): 1141-1147, 2008

Development of sympathetic cardiovascular control in embryonic, hatchling, and yearling female American alligator (Alligator mississippiensis). Comparative Biochemistry and Physiology. Part A Molecular and Integrative Physiology 165(2): 272-280, 2013

In vivo locomotor strain in the hindlimb bones of alligator mississippiensis and iguana iguana: implications for the evolution of limb bone safety factor and non-sprawling limb posture. Journal of Experimental Biology 202: 1023-1046, 1999

Hind limb movements of the american alligator alligator mississippiensis and postural grades. Journal of Zoology (London) 224(4): 577-588, 1991

Effects of bacterial lipopolysachharide on peripheral leukocytes in the American alligator (Alligator mississippiensis). Veterinary immunology and immunopathology 111(3-4): 315-320, 2006

Second hatching of the American alligator Alligator mississippiensis at the Australian Reptile Park, Gosford. International Zoo Yearbook 21: 76-77, 1981

Development and characterization of tetranucleotide microsatellite loci for the American alligator Alligator mississippiensis. Conservation Genetics Resources 4(3): 567-570, 2012

Developmental effects of embryonic exposure to toxaphene in the American alligator (Alligator mississippiensis). Comparative Biochemistry and Physiology. Toxicology and Pharmacology: Cbp 138(1): 81-87, 2004

Age-class differences in lipids from the paracloacal glands of the American alligator (Alligator mississippiensis). Zeitschrift fuer Naturforschung Section C Journal of Biosciences 53(3-4): 201-209, 1998

Terrestrial locomotion does not constrain venous return in the American alligator, Alligator mississippiensis. Journal of experimental biology 208(Pt 17): 3331-3339, 2005

Morphology and histochemistry of juvenile male American alligator (Alligator mississippiensis) phallus. Anatomical Record 295(2): 328-337, 2012

Night counts as an index of american alligator alligator mississippiensis population trends. Wildlife Society Bulletin 13(3): 262-272, 1985