Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-26T18:52:21.790Z Has data issue: false hasContentIssue false
  • English
  • Français

Segmental variation in the activity and function of the equine longissimus dorsi muscle during walk and trot

Published online by Cambridge University Press:  01 May 2007

James M Wakeling ,
Pattama Ritruechai ,
Sarah Dalton  and
Kathryn Nankervis
James M Wakeling*
Affiliation:
Structure and Motion Laboratory, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK
Pattama Ritruechai
Affiliation:
Structure and Motion Laboratory, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK
Sarah Dalton
Affiliation:
Structure and Motion Laboratory, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK
Kathryn Nankervis
Affiliation:
Hartpury Equine Veterinary and Therapy Centre, Hartpury College, Hartpury, Gloucestershire GL19 3BE, UK
*
*Corresponding author: wakeling@sfu.ca
Get access

Abstract

Muscle function depends in part on the interplay between its activity and its length within the stretch-shortening cycle. The longissimus dorsi is a large epaxial muscle running along the thoracic and lumbar regions of the equine back. Due to its anatomical positioning, the longissimus dorsi has the capability of contributing to many functions: developing bending moments in the dorsoventral and lateral (coupled to axial rotation) directions and also providing stiffness to limit motion in these directions. We hypothesize that the exact function of the longissimus dorsi will vary along the back and between gaits as the relation between activity and motion of the back changes. Electromyograms (EMG) were recorded at walk (inclined and level) and trot (on the level) on a treadmill from the longissimus dorsi at muscle segments T14, T16, T18 and L2. Back motion was additionally measured using a fibre-optic goniometer. Co-contractions of the muscle between its left and right sides were quantified using correlation analysis. A greater dominance of unilateral activity was found at more cranial segments and for level walking, suggesting a greater role of the longissimus dorsi in developing lateral bending moments. Timing of the EMG varied between muscle segments relative to the gait cycle, the locomotor condition tested and the flexion–extension cycle of the back. This supports the hypothesis that the function of the longissimus dorsi changes along the back and between gaits.

Keywords

equineEMGflexionbacklongissimus dorsi
Type
Research Paper
Information
Equine and Comparative Exercise Physiology , Volume 4 , Issue 2 , May 2007 , pp. 95 - 103
Copyright
Copyright © Cambridge University Press 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1Haussler, KK (1999). Anatomy of the thoracolumbar vertebral region. Veterinary Clinics of North America: Equine Practice 15: 13–26.Google ScholarPubMed
2Wakeling, JM, Barnett, K, Price, S and Nankervis, K (2006). Effects of manipulative therapy on the longissimus dorsi in the equine back. Equine and Comparative Exercise Physiology 3: 153–160.CrossRefGoogle Scholar
3Audigie, F, Pourcelot, P, Degueurce, C, Denoix, JM and Geiger, D (1999). Kinematics of the equine back: flexion–extension movements in sound trotting horses. Equine Veterinary Journal Suppliment 30: 210–213.CrossRefGoogle Scholar
4Robert, C, Audigie, F, Valette, JP, Pourcelot, P and Denoix, JM (2001). Effects of treadmill speed on the mechanics of the back in the trotting saddlehorse. Equine Veterinary Journal Suppliment 33: 154–159.CrossRefGoogle Scholar
5Faber, M, Johnston, C and Schamhardt, H (2001). Basic three-dimensional kinematics of the vertebral column of horses trotting on a treadmill. American Journal of Veterinary Research 62: 757–764.CrossRefGoogle ScholarPubMed
6Faber, M, Schamhardt, H and van Weeren, R (2000). Basic three-dimensional kinematics of the vertebral column of horses walking on a treadmill. American Journal of Veterinary Research 61: 399–406.CrossRefGoogle ScholarPubMed
7Peham, C and Schobesberger, H (2006). A novel method to estimate the stiffness of the equine back. Journal of Biomechanics 39: 2845–2849.CrossRefGoogle ScholarPubMed
8Schlacher, C, Peham, C, Licka, T and Schobesberger, H (2004). Determination of the stiffness of the equine spine. Equine Veterinary Journal 36: 699–702.CrossRefGoogle ScholarPubMed
9Drake, JDM and Callaghan, JP (2006). Elimination of electrocardiogram contamination from electromyogram signals: an evaluation of currently used removal techniques. Journal of Electromyography and Kinesiology 16: 175–187.CrossRefGoogle ScholarPubMed
10von Tsharner, V (2000). Intensity analysis in time-frequency space of surface myoelectric signals by wavelets of specified resolution. Journal of Electromyography and Kinesiology 10: 433–445.CrossRefGoogle Scholar
11Wakeling, JM, Kaya, M, Temple, GK and Johnston, IA (2002). Determining patterns of motor recruitment during locomotion. Journal of Experimental Biology 205: 359–369.CrossRefGoogle ScholarPubMed
12Ramsay, JO and Silverman, BW (1997). Functional data analysis. New York: Springer, pp. 310.CrossRefGoogle Scholar
13Robert, C, Valette, JP and Denoix, JM (2001). The effects of treadmill inclination and speed on the activity of three trunk muscles in the trotting horse. Equine veterinary Journal 33: 466–472.CrossRefGoogle ScholarPubMed
14Robert, C, Valette, JP, Pourcelot, P, Audigie, F and Denoix, JM (2002). Effects of trotting speed on muscle activity and kinematics in saddlehorses. Equine Veterinary Journal Suppliment 34: 295–301.CrossRefGoogle Scholar
15Licka, TF, Peham, C and Frey, A (2004). Electromyographic activity of the longissimus dorsi muscles in horses during trotting on a treadmill. American Journal of Veterinary Research 65: 155–158.CrossRefGoogle ScholarPubMed
16Jeffcott, LB and Dalin, G (1980). Natural rigidity of the horse's backbone. Equine Veterinary Journal 12: 101–108.CrossRefGoogle Scholar
17Townsend, HG, Leach, DH and Fretz, PB (1983). Kinematics of the equine thoracolumbar spine. Equine Veterinary Journal 15: 117–122.18.CrossRefGoogle ScholarPubMed
18Denoix, JM (1999). Spinal biomechanics and functional anatomy. Veterinary Clinics of North America: Equine Practice 15: 27–60.Google ScholarPubMed
19Licka, TF, Peham, C and Zohmann, E (2001). Treadmill study of the range of back movement at the walk in horses without back pain. American Journal of Veterinary Research 62: 1173–1179.CrossRefGoogle ScholarPubMed
20Pain, HJ (2002). The physics of vibrations and waves. 5th edn. Chichester, UK: John Wiley & Sons Ltd., pp. 559.Google Scholar