FREE SHIPPING over $40
OVER 9000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Home / Equine Research Bank / Anat Histol Embryol / Nerve entry points in the mimic musculature of the horse hea...
Anatomia, histologia, embryologia2024; 53(5); e13099; doi: 10.1111/ahe.13099

Nerve entry points in the mimic musculature of the horse head.

Abstract: Facial expressions are important in pain recognition in horses, but current observation-based pain scales remain subjective. A promising technique to quantitatively measure subtle changes in expression patterns, including changes invisible to the human eye, is surface electromyography (sEMG). To achieve high-quality and reliable sEMG signals, unilateral placement of bipolar electrodes is required in relation to the motor endplates (MEP). We aimed to localize the nerve entry points (NEPs; where the nerve branch first pierced the muscle belly) and the direction of the terminal nerve endings to estimate MEP locations of the innervating nerves in five equine facial muscles involved in pain expression. Three cadaveric Dutch Warmblood horse heads were dissected to identify the NEPs in the musculi caninus, levator anguli oculi medialis, nasolabialis, masseter and zygomaticus. These points were marked with pins and measured in relation to a reference line between two anatomical landmarks near the origin and insertion of the respective muscle. Relative distances were calculated from the most caudally situated landmark. NEPs were located at 33%-38% (caninus), 69%-86% (levator anguli oculi medialis) and 0%-18% (zygomaticus) from the caudal landmark. The nasolabialis showed two innervations zones. Its NEPs were located at 47%-72% (dorsal muscle branch) and 52%-91% (ventral branch). All terminal nerve endings were found to run in rostral direction. The masseter showed numerous NEPs diffusely spread within the muscle belly. Therefore, calculation of relative positions was not performed. These results could form the basis for feasibility studies and standardization of bipolar electrode positioning in vivo to measure facial muscle activity patterns in horses.
© 2024 The Author(s). Anatomia, Histologia, Embryologia published by Wiley‐VCH GmbH.
Get Full Text
Publication Date: 2024-08-05 PubMed ID: 39099214DOI: 10.1111/ahe.13099Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
LinkedInCopy
  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research focuses on understanding facial expressions in horses, specifically pinpointing nerve entry points (NEPs) in their facial muscles to enable more accurate surface electromyography (sEMG) measurements. The goal is to use these electromyography metrics to provide an objective assessment of pain levels in horses, thus standardizing the currently subjective pain scales based on observational data.

Objective of the Study

  • The study aims to investigate the NEPs of nerves that innervate facial muscles in horses. These facial muscles have been identified as significant in expressing pain in these organisms.
  • The researchers hope that by understanding the exact neuroanatomical locations of where nerve branches enter the facial muscle belly, they can improve sEMG readings. This is based on the theory that getting the electrodes of sEMG devices closer to the motor endplates (MEPs; the part of the muscle receiving innervation from the nerve) enhances the quality of the electrical signal picked up.

Methodology of the Study

  • The study was performed on three cadaveric Dutch Warmblood horse heads. The team dissected these specimens to find out and mark the NEPs in five muscle types: the musculi caninus, levator anguli oculi medialis, nasolabialis, masseter, and zygomaticus.
  • After identifying the NEPs, researchers measured their locations relative to a reference line drawn between two anatomical landmarks for each muscle. The point found deepest within each muscle served as the caudal landmark.

Findings of the Study

  • The research found distinct NEPs for the musculi caninus (33%-38% from the caudal landmark), levator anguli oculi medialis (69%-86%), and zygomaticus (0%-18%). The nasolabialis was observed to have two innervation zones, with NEPs along both dorsal (47%-72%) and ventral (52%-91%) muscle branches.
  • All terminal nerve endings were found to direct towards the rostral, or frontward, direction.
  • The masseter muscle showed a significant number of NEPs spread within the muscle belly. Hence, relative position calculations were not possible in this case.

Implications of the Study

  • This research aids in refining the process of bipolar electrode placement for sEMG in horses, ultimately improving the understanding and treatment of pain in these creatures.
  • The findings can guide future studies and standardization protocols for the measurement of facial muscle activity patterns in horses. This can serve as a foundation for quantitative pain recognition in horses, reducing subjectivity in pain evaluation.

Cite This Article

APA
Wolschrijn CF, Smit IH, Schouten J, Moller Te NCR. (2024). Nerve entry points in the mimic musculature of the horse head. Anat Histol Embryol, 53(5), e13099. https://doi.org/10.1111/ahe.13099

Publication

Anatomia, histologia, embryologia
ISSN: 1439-0264
NlmUniqueID: 7704218
Country: Germany
Language: English
Volume: 53
Issue: 5
Pages: e13099

Researcher Affiliations

Wolschrijn, C F
  • Section of Anatomy and Physiology, Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
Smit, I H
  • Section of Equine Musculoskeletal Biology, Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
Schouten, J
  • Section of Anatomy and Physiology, Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
Moller Te, N C R
  • Section of Equine Musculoskeletal Biology, Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.

MeSH Terms

  • Animals
  • Horses / anatomy & histology
  • Facial Muscles / innervation
  • Facial Muscles / anatomy & histology
  • Electromyography / veterinary
  • Head / innervation
  • Head / anatomy & histology
  • Facial Expression
  • Motor Endplate / anatomy & histology
  • Cadaver

Grant Funding

  • Utrecht University Faculteit diergeneeskunde

References

This article includes 32 references
  1. An XC, Lee JH, Im S, Lee MS, Hwang K, Kim HW, Han SH. Anatomic localization of motor entry points and intramuscular nerve endings in the hamstring muscles. Surgical and Radiologic Anatomy: SRA 32(6), 529–537 (2010).
    doi: 10.1007/s00276-009-0609-5google scholar: lookup
  2. Anderson KA, Morrice-West AV, Wong ASM, Walmsley EA, Fisher AD, Whitton RC, Hitchens PL. Poor association between facial expression and mild lameness in thoroughbred trot‐up examinations. Animals 13(11), Article 11 (2023).
    doi: 10.3390/ani13111727google scholar: lookup
  3. Ask K, Rhodin M, Rashid-Engström M, Hernlund E, Andersen PH. Changes in the equine facial repertoire during different orthopedic pain intensities. Scientific Reports 14(1), 129 (2024).
    doi: 10.1038/s41598-023-50383-ygoogle scholar: lookup
  4. Barone R. Anatomie comparée des mammifères domestiques, tome second arthrologie et myologie (4th ed.). .
  5. Beretta Piccoli M, Rainoldi A, Heitz C, Wüthrich M, Boccia G, Tomasoni E, Spirolazzi C, Egloff M, Barbero M. Innervation zone locations in 43 superficial muscles: Toward a standardization of electrode positioning. Muscle & Nerve 49(3), 413–421 (2014).
    doi: 10.1002/mus.23934google scholar: lookup
  6. Czycholl I, Klingbeil P, Krieter J. Interobserver reliability of the animal welfare indicators welfare assessment protocol for horses. Journal of Equine Veterinary Science 75, 112–121 (2019).
    doi: 10.1016/j.jevs.2019.02.005google scholar: lookup
  7. Dalla Costa E, Minero M, Lebelt D, Stucke D, Canali E, Leach MC. Development of the horse grimace scale (HGS) as a pain assessment tool in horses undergoing routine castration. PLoS One 9(3), 1–10 (2014).
    doi: 10.1371/journal.pone.0092281google scholar: lookup
  8. De Bonnecaze G, Vergez S, Chaput B, Vairel B, Serrano E, Chantalat E, Chaynes P. Variability in facial‐muscle innervation: A comparative study based on electrostimulation and anatomical dissection. Clinical Anatomy 32(2), 169–175 (2019).
    doi: 10.1002/ca.23081google scholar: lookup
  9. de Grauw JC, van Loon JPAM. Systematic pain assessment in horses. Veterinary Journal 209, 14–22 (2016).
    doi: 10.1016/j.tvjl.2015.07.030google scholar: lookup
  10. De Luca CJ. The use of surface electromyography in biomechanics. Journal of Applied Biomechanics 13(2), 135–163 (1997).
    doi: 10.1123/jab.13.2.135google scholar: lookup
  11. De Luca CJ, Gilmore LD, Kuznetsov M, Roy SH. Filtering the surface EMG signal: Movement artifact and baseline noise contamination. Journal of Biomechanics 43(8), 1573–1579 (2010).
    doi: 10.1016/j.jbiomech.2010.01.027google scholar: lookup
  12. Diogo R, Wood BA, Aziz MA, Burrows A. On the origin, homologies and evolution of primate facial muscles, with a particular focus on hominoids and a suggested unifying nomenclature for the facial muscles of the Mammalia. Journal of Anatomy 215(3), 300–319 (2009).
    doi: 10.1111/j.1469-7580.2009.01111.xgoogle scholar: lookup
  13. Ferlini Agne G, May BE, Lovett A, Simon O, Steel C, Santos L, Guedes do Carmo L, Barbosa B, Werner LC, Daros RR, Somogyi AA, Sykes B, Franklin S. Horse grimace scale does not detect pain in horses with equine gastric ulcer syndrome. Animals 13(10), 1623 (2023).
    doi: 10.3390/ani13101623google scholar: lookup
  14. Gleerup KB, Forkman B, Lindegaard C, Andersen PH. An equine pain face. Veterinary Anaesthesia and Analgesia 42(1), 103–114 (2015).
    doi: 10.1111/vaa.12212google scholar: lookup
  15. Guntinas-Lichius O, Silver CE, Thielker J, Bernal-Sprekelsen M, Bradford CR, De Bree R, Kowalski LP, Olsen KD, Quer M, Rinaldo A, Rodrigo JR, Sanabria A, Shaha AR, Takes RP, Vander Poorten V, Zbären P, Ferlito A. Management of the facial nerve in parotid cancer: Preservation or resection and reconstruction. European Archives of Oto‐Rhino‐Laryngology 275(11), 2615–2626 (2018).
    doi: 10.1007/s00405-018-5154-6google scholar: lookup
  16. Happak W, Liu J, Burggasser G, Flowers A, Gruber H, Freilinger G. Human facial muscles: Dimensions, motor endplate distribution, and presence of muscle fibers with multiple motor endplates. The Anatomical Record 249(2), 276–284 (1997).
    doi: 10.1002/(sici)1097-0185(199710)249:2<276::aid-ar15>3.0.co;2-lgoogle scholar: lookup
  17. Heck L, Sanchez-Villagra MR, Stange M. Why the long face? Comparative shape analysis of miniature, pony, and other horse skulls reveals changes in ontogenetic growth. PeerJ 7, e7678 (2019).
    doi: 10.7717/peerj.7678google scholar: lookup
  18. Hermens HJ, Freriks B, Disselhorst-Klug C, Rau G. Development of recommendations for SEMG sensors and sensor placement procedures. Journal of Electromyography and Kinesiology 10(5), 361–374 (2000).
    doi: 10.1016/s1050-6411(00)00027-4google scholar: lookup
  19. Koo TK, Li MY. A guideline of selecting and reporting intraclass correlation coefficients for reliability research. Journal of Chiropractic Medicine 15(2), 155–163 (2016).
    doi: 10.1016/j.jcm.2016.02.012google scholar: lookup
  20. Mieronkoski Id R, Syrjä Lä E, Jiang M, Rahmani A, Pahikkala T, Liljeberg P, Salanterä S. Developing a pain intensity prediction model using facial expression: A feasibility study with electromyography. PLoS One 15(7), e0235545 (2020).
    doi: 10.1371/journal.pone.0235545google scholar: lookup
  21. Murgia M, de Sire A, Ruiu P, Agostini F, Bai AV, Pintabona G, Paolucci T, Bemporad J, Paoloni M, Bernetti A. Botulinum toxin type A for spasticity in cerebral palsy patients: Which impact on popliteal angle to hamstring length? A proof‐of‐concept study. Journal of Back and Musculoskeletal Rehabilitation 36(5), 1193–1201 (2023).
    doi: 10.3233/bmr-220381google scholar: lookup
  22. Peppermüller PP, Gehring J, Zentrich E, Bleich A, Häger C, Buettner M. Grimace scale assessment during Citrobacter rodentium inflammation and colitis development in laboratory mice. Frontiers in Veterinary Science 10, 1173446 (2023).
    doi: 10.3389/fvets.2023.1173446google scholar: lookup
  23. Rainoldi A, Nazzaro M, Merletti R, Farina D, Caruso I, Gaudenti S. Geometrical factors in surface EMG of the vastus medialis and lateralis muscles. Journal of Electromyography and Kinesiology 10(5), 327–336 (2000).
    doi: 10.1016/s1050-6411(00)00024-9google scholar: lookup
  24. Rashid M, Silventoinen A, Gleerup KB, Andersen PH. Equine facial action coding system for determination of pain‐related facial responses in videos of horses. PLoS One 15, 1–18 (2020).
    doi: 10.1371/journal.pone.0231608google scholar: lookup
  25. Schumann NP, Bongers K, Guntinas-Lichius O, Scholle HC. Facial muscle activation patterns in healthy male humans: A multi‐channel surface EMG study. Journal of Neuroscience Methods 187(1), 120–128 (2010).
    doi: 10.1016/j.jneumeth.2009.12.019google scholar: lookup
  26. Sing B. Dyce, Sack, and Wensing's textbook of veterinary anatomy. .
  27. Standring S. Gray's anatomy: The anatomical basis of clinical practice (42nd ed.). .
  28. Taylor PM, Pascoe PJ, Mama KR. Diagnosing and treating pain in the horse: Where are we today?. Veterinary Clinics of North America: Equine Practice 18(1), 1–19 (2002).
    doi: 10.1016/s0749-0739(02)00009-3google scholar: lookup
  29. Torcivia C, McDonnell S. In‐person caretaker visits disrupt ongoing discomfort behavior in hospitalized equine orthopedic surgical patients. Animals 10(2), 210–222 (2020).
    doi: 10.3390/ani10020210google scholar: lookup
  30. van Loon JPAM, Van Dierendonck MC. Monitoring acute equine visceral pain with the Equine Utrecht University Scale for Composite Pain Assessment (EQUUS‐COMPASS) and the equine Utrecht University Scale for Facial Assessment of Pain (EQUUS‐FAP): A scale‐construction study. Veterinary Journal 206(3), 356–364 (2015).
    doi: 10.1016/j.tvjl.2015.08.023google scholar: lookup
  31. Vieira TM, Botter A. The accurate assessment of muscle excitation requires the detection of multiple surface electromyograms. Exercise and Sport Sciences Reviews 49(1), 23–34 (2021).
    doi: 10.1249/jes.0000000000000240google scholar: lookup
  32. Wathan J, Burrows AM, Waller BM, McComb K. EquiFACS: The equine facial action coding system. PLoS One 10(8), 1–35 (2015).
    doi: 10.1371/journal.pone.0131738google scholar: lookup
Subscribe to our newsletter
Join 99,021 horse owners like you who receive our email updates on horse health and nutrition.