Forelimb muscle activity during equine locomotion

Simon M. Harrison, R. Chris Whitton, Melissa King, Kevin K. Haussler, Chris E. Kawcak, Susan M Stover, Marcus G. Pandy

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Few quantitative data exist to describe the activity of the distal muscles of the equine forelimb during locomotion, and there is an incomplete understanding of the functional roles of the majority of the forelimb muscles. Based on morphology alone it would appear that the larger proximal muscles perform the majority of work in the forelimb, whereas the smaller distal muscles fulfil supplementary roles such as stabilizing the joints and positioning the limb for impact with the ground. We measured the timing and amplitude of the electromyographic activity of the intrinsic muscles of the forelimb in relation to the phase of gait (stance versus swing) and the torque demand placed on each joint during walking, trotting and cantering. We found that all forelimb muscles, except the extensor carpi radialis (ECR), were activated just prior to hoof-strike and deactivated during stance. Only the ECR was activated during swing. The amplitudes of muscle activation typically increased as gait speed increased. However, the amplitudes of muscle activation were not proportional to the net joint torques, indicating that passive structures may also contribute significantly to torque generation. Our results suggest that the smaller distal muscles help to stabilize the forelimb in early stance, in preparation for the passive structures (tendons and ligaments) to be stretched. The distal forelimb muscles remain active throughout stance only during canter, when the net torques acting about the distal forelimb joints are highest. The larger proximal muscles activate in a complex coordination to position and stabilize the shoulder and elbow joints during ground contact.

Original languageEnglish (US)
Pages (from-to)2980-2991
Number of pages12
JournalJournal of Experimental Biology
Volume215
Issue number17
DOIs
StatePublished - Sep 2012

Fingerprint

Forelimb
locomotion
Locomotion
forelimbs
Horses
muscle
horses
Muscles
muscles
torque
Torque
joints (animal)
Joints
carpus
gait
equine
coordination compounds
trotting
Elbow Joint
Hoof and Claw

Keywords

  • Canter
  • EMG
  • Equine gait
  • Joint torque
  • Quadrupedal biomechanics
  • Trot
  • Walk

ASJC Scopus subject areas

  • Animal Science and Zoology
  • Ecology, Evolution, Behavior and Systematics
  • Molecular Biology
  • Physiology
  • Insect Science
  • Aquatic Science

Cite this

Harrison, S. M., Whitton, R. C., King, M., Haussler, K. K., Kawcak, C. E., Stover, S. M., & Pandy, M. G. (2012). Forelimb muscle activity during equine locomotion. Journal of Experimental Biology, 215(17), 2980-2991. https://doi.org/10.1242/jeb.065441

Forelimb muscle activity during equine locomotion. / Harrison, Simon M.; Whitton, R. Chris; King, Melissa; Haussler, Kevin K.; Kawcak, Chris E.; Stover, Susan M; Pandy, Marcus G.

In: Journal of Experimental Biology, Vol. 215, No. 17, 09.2012, p. 2980-2991.

Research output: Contribution to journalArticle

Harrison, SM, Whitton, RC, King, M, Haussler, KK, Kawcak, CE, Stover, SM & Pandy, MG 2012, 'Forelimb muscle activity during equine locomotion', Journal of Experimental Biology, vol. 215, no. 17, pp. 2980-2991. https://doi.org/10.1242/jeb.065441
Harrison SM, Whitton RC, King M, Haussler KK, Kawcak CE, Stover SM et al. Forelimb muscle activity during equine locomotion. Journal of Experimental Biology. 2012 Sep;215(17):2980-2991. https://doi.org/10.1242/jeb.065441
Harrison, Simon M. ; Whitton, R. Chris ; King, Melissa ; Haussler, Kevin K. ; Kawcak, Chris E. ; Stover, Susan M ; Pandy, Marcus G. / Forelimb muscle activity during equine locomotion. In: Journal of Experimental Biology. 2012 ; Vol. 215, No. 17. pp. 2980-2991.
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