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Estimation of locomotory forces and stresses in the limb bones of Recent and extinct equids

Published online by Cambridge University Press:  08 April 2016

J. J. Thomason*
Affiliation:
Department of Vertebrate Palaeontology, Royal Ontario Museum, 100 Queens Park, Toronto, Ontario M5S 2C6, Canada Department of Zoology, University of Toronto, Toronto, Ontario M5S 1A1, Canada

Abstract

The locomotory stresses acting at the midshaft of the third metacarpal of Equus are estimated from a geometrical model of the manus during peak loading, which is derived from in vivo data. The stress results compare favorably with those from in vivo strain gage experiments. The model is then modified to account for the anatomical and inferred functional differences in the feet of the two extinct, tridactyl equids Merychippus and Mesohippus, incorporating assumptions from earlier functional studies. Estimates of the stresses in the fossil metacarpals are derived, and fall within the range of values obtained in vivo for limb bones of a wide size range of mammals. The results indicate that the third metacarpal of Merychippus was the most highly stressed and that of Mesohippus the least, with stresses for Equus falling between. Thus the anatomical and functional changes in the manus between Mesohippus and Equus are not simply a result of the difference in body size.

Type
Articles
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Alexander, R. McN. 1974. The mechanics of jumping by a dog, Canis familiaris. J. Zool. 173:549573.CrossRefGoogle Scholar
Alexander, R. McN. 1983. On the massive legs of a moa (Pachyornis elephantopus, Dinornithes). J. Zool. 201:363376.Google Scholar
Alexander, R. McN., Jayes, A. S., Maloiy, G. M. O., and Wathuta, E. M. 1979a. Allometry of the limb bones of mammals from shrews (Sorex) to elephants (Loxodonta). J. Zool. 189:305314.Google Scholar
Alexander, R. McN., Maloiy, G. M. O., Hunter, B., Jayes, A. S., and Nturibi, J. 1979b. Mechanical stresses in fast locomotion of buffaloes (Syncerus caffer) and elephants (Loxodonta africana). J. Zool. 189:135144.CrossRefGoogle Scholar
Badoux, D. M. 1966. Mechanics of the acropodium of the horse: a practical application of photoelastic research. Tijdschr. Diergeneeskd. 91:12071232.Google Scholar
Badoux, D. M. 1972. Biomechanics of the autopodium of the equine hindleg. Proc. K. Ned. Akad. Wet., Ser. C, 75:224242.Google Scholar
Badoux, D. M. 1975. Some notes on stress and strain in the phalanges of the equine foot. Proc. K. Ned. Akad. Wet., Ser. C, 78:2532.Google Scholar
Barnes, G. R. G. and Pinder, D. N. 1974. In vivo tendon tension and bone strain measurement and correlation. J. Biomech. 7:239245.CrossRefGoogle ScholarPubMed
Bartel, D. L., Schryver, H. F., Lowe, J. E., and Parker, R. A. 1978. Locomotion in the horse: a procedure for computing the internal forces in the digit. Am. J. Vet. Res. 39:17211728.Google Scholar
Biewener, A. A. 1981. Safety factors in the skeletal design of large and small animals: are they uniform? Am. Zool. 20:937.Google Scholar
Biewener, A. A. 1982. Bone strength in small mammals and bipedal birds: do safety factors change with body size? J. Exp. Biol. 98:289301.Google Scholar
Biewener, A. A. 1983. Allometry of quadrupedal locomotion: the scaling of duty factor, bone curvature and limb orientation to body size. J. Exp. Biol. 105:147171.CrossRefGoogle ScholarPubMed
Biewener, A. A., Thomason, J. J., Goodship, A. E., and Lanyon, L. E. 1983a. Bone stress in the horse forelimb during locomotion at different gaits: a comparison of two experimental methods. J. Biomech. 16:565576.Google Scholar
Biewener, A. A., Thomason, J. J., and Lanyon, L. E. 1983b. Mechanics of locomotion and jumping in the horse forelimb: in vivo stress developed in the radius and metacarpus. J. Zool. 201:6782.Google Scholar
Camp, C. L. and Smith, N. 1942. Phylogeny and functions of the digital ligaments of the horse. Mem. Univ. Calif., Berkeley No. 13:173.Google Scholar
Carter, D. R., Vasu, R., Spengler, D. M., and Dueland, R. T. 1981. Stress fields around the plated and unplated canine femur calculated from in vivo strain measurements. J. Biomech. 14:6370.Google Scholar
Case, J. and Chilver, A. H. 1971. Strength of Materials and Structures. 2d ed.Edward Arnold; London. 404 pp.Google Scholar
Cochran, G. V. B. 1972. Implantation of strain gauges on bone in vivo. J. Biomech. 5:119123.Google Scholar
Gray, J. 1944. Studies in the mechanics of the tetrapod skeleton. J. Exp. Biol. 20:88116.CrossRefGoogle Scholar
Gregory, W. K. 1912. Notes on the principles of quadrupedal locomotion and on the mechanics of the limb in hooved mammals. Ann. N.Y. Acad. Sci. 22:267294.CrossRefGoogle Scholar
Howell, A. B. 1944. Speed in Animals. Univ. Chicago Press; Chicago. 270 pp.Google Scholar
Jayes, A. S. and Alexander, R. McN. 1978. Mechanics of locomotion of dogs (Canis familiaris) and sheep (Ovis aries). J. Zool. 185:289308.CrossRefGoogle ScholarPubMed
Lanyon, L. E. 1976. The measurement of bone strain in vivo. Acta Orthop. Belg. 42:98108.Google Scholar
Lanyon, L. E., Magee, P. T., and Baggott, D. G. 1979. The relationship of functional stress and strain to the process of bone remodelling; an experimental study on the sheep radius. J. Biomech. 12:593600.Google Scholar
McMahon, T. A. 1975. Allometry and biomechanics: limb bones of adult ungulates. Am. Nat. 109:547563.CrossRefGoogle Scholar
Schryver, H. F., Bartel, D. L., Langrana, N., and Lowe, J. E. 1978. Locomotion in the horse: kinematics and external and internal forces in the normal equine digit in the walk and trot. Am. J. Vet. Res. 39:17281733.Google Scholar
Shotwell, J. A. 1961. Late Tertiary biogeography of horses in the northern Great Basin. J. Paleontol. 35:203217.Google Scholar
Simpson, G. G. 1951. Horses. Oxford Univ. Press; Oxford. 247 pp.Google Scholar
Smith, J. M. and Savage, R. J. G. 1956. Some locomotory adaptations in mammals. Zool. J. Linn. Soc. 42:603622.CrossRefGoogle Scholar
Sondaar, P. Y. 1968. The osteology of the manus of fossil and Recent Equidae. Verh. K. Ned. Akad. Wet. 25:176.Google Scholar
Thomason, J. J. In preparation. Locomotion in the extinct tridactyl equids Merychippus and Mesohippus: paleontological inferences from neontological models. Submitted.Google Scholar
Thompson, D'A. W. 1917. On Growth and Form. Abridged and republished 1961, Bonner, J. T., ed. Cambridge Univ. Press; Cambridge. 345 pp.Google Scholar