Pharyngeal diameter in various head and neck positions during exercise in sport horses.
Abstract: In equine athletes, dynamic stenotic disorders of the upper airways are often the cause for abnormal respiratory noises and/or poor performance. There are hypotheses, that head and neck flexion may influence the morphology and function of the upper airway and thus could even induce or deteriorate disorders of the upper respiratory tract. Especially the pharynx, without osseous or cartilaginous support is prone to changes in pressure and airflow during exercise. The objective of this study was to develop a method for measuring the pharyngeal diameter in horses during exercise, in order to analyse whether a change of head-neck position may have an impact on the pharyngeal diameter. Results: Under the assumption that the width of the epiglottis remains constant in healthy horses, the newly developed method for calculating the pharyngeal diameter in horses during exercise is unsusceptible against changes of the viewing-angle and distance between the endoscope and the structures, which are to be assessed. The quotient of the width of the epiglottis and the perpendicular from a fixed point on the dorsal pharynx to the epiglottis could be used to determine the pharyngeal diameter. The percentage change of this quotient (pharynx-epiglottis-ratio; PE-ratio) in the unrestrained head-neck position against the reference position was significantly larger than that of any other combination of the head-neck positions investigated. A relation between the percentage change in PE-ratio and the degree of head and neck flexion could not be confirmed. Conclusions: It could be shown, that the pharyngeal diameter is reduced through the contact position implemented by the rider in comparison to the unrestrained head and neck position. An alteration of the pharyngeal diameter depending on the degree of head and neck flexion (represented by ground and withers angle) could not be confirmed.
Publication Date: 2014-05-23 PubMed ID: 24886465PubMed Central: PMC4057621DOI: 10.1186/1746-6148-10-117Google Scholar: Lookup
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Summary
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This research investigated if the position of a sport horse’s head and neck during exercise influences the diameter of their pharynx. It also developed a novel method for measure this effect. The study found that the pharynx size is reduced when the horse’s head and neck are controlled by the rider, but that the degree of head and neck flexion did not seem to have an impact.
Research Objectives and Hypotheses
- This study aimed to understand the effect of head and neck positions in sport horses on the morphology and function of their upper airway during exercise. Specifically, it focused on the diameter of the pharynx.
- Researchers hypothesized that the change of head and neck position could impact the pharynx’s diameter, potentially inducing or exacerbating upper respiratory tract disorders.
Developed Methodology
- The researchers developed a new method for measuring the pharyngeal diameter in horses during exercise.
- The method is based on the assumption that the epiglottis width remains constant in healthy horses.
- This involves calculating a ratio (termed the pharynx-epiglottis-ratio or PE-ratio) using the width of the epiglottis and the perpendicular distance from a fixed point on the dorsal pharynx to the epiglottis.
Findings
- The study found that the change in the PE-ratio from the horse’s unrestrained head-neck position to the reference position was significantly larger than the change in any other head-neck positions studied.
- The pharyngeal diameter was found to be reduced when the horse’s head and neck were controlled by the rider as compared to an unrestrained position, thus validating the assumptions made at the start of the study.
- The researchers did not confirm a relationship between the percentage change in the PE-ratio and the degree of head and neck flexion. This suggests that the diameter of the pharynx does not change significantly with the degree of head and neck flexion and that other factors like rider control may have greater impact.
Cite This Article
APA
Go LM, Barton AK, Ohnesorge B.
(2014).
Pharyngeal diameter in various head and neck positions during exercise in sport horses.
BMC Vet Res, 10, 117.
https://doi.org/10.1186/1746-6148-10-117 Publication
Researcher Affiliations
- Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Bünteweg 9, Hannover D-30559, Germany. li-mei.go@gmx.ch.
MeSH Terms
- Animals
- Epiglottis / anatomy & histology
- Epiglottis / physiology
- Female
- Horses / anatomy & histology
- Horses / physiology
- Male
- Pharynx / anatomy & histology
- Physical Conditioning, Animal / physiology
- Posture
References
This article includes 29 references
- Robinson NE, Sorenson PR. Pathophysiology of airway obstruction in horses: a review.. J Am Vet Med Assoc 1978 Feb 1;172(3):299-303.
- Franklin SH. Dynamic collapse of the upper respiratory tract: A review.. Equine Veterinary Education 2008;20:212–224.
- Stick JA. Physiology of upper airway obstruction, obstructive pharyngeal disease.. J Equine Vet Sci 1990;10:82.
- Kannegieter NJ, Dore ML. Endoscopy of the upper respiratory tract during treadmill exercise: a clinical study of 100 horses.. Aust Vet J 1995 Mar;72(3):101-7.
- Lane JG, Bladon B, Little DR, Naylor JR, Franklin SH. Dynamic obstructions of the equine upper respiratory tract. Part 1: observations during high-speed treadmill endoscopy of 600 Thoroughbred racehorses.. Equine Vet J 2006 Sep;38(5):393-9.
- Tan RH, Dowling BA, Dart AJ. High-speed treadmill videoendoscopic examination of the upper respiratory tract in the horse: the results of 291 clinical cases.. Vet J 2005 Sep;170(2):243-8.
- Desmaizieres LM, Serraud N, Plainfosse B, Michel A, Tamzali Y. Dynamic respiratory endoscopy without treadmill in 68 performance Standardbred, Thoroughbred and saddle horses under natural training conditions.. Equine Vet J 2009 Apr;41(4):347-52.
- Pollock PJ, Reardon RJ, Parkin TD, Johnston MS, Tate J, Love S. Dynamic respiratory endoscopy in 67 Thoroughbred racehorses training under normal ridden exercise conditions.. Equine Vet J 2009 Apr;41(4):354-60.
- Meyer H. “Rollkur”, “Hyperflexion” and “LDR” - The natural position of the head and neck of the horse and the modification by the rider.. Pferdeheilkd 2010;26:388–413.
- Cook WR. A solution to respiratory and other problems of the horse caused by the bit.. Pferdeheilkd 2000;16:333–351.
- Cehak A, Rohn K, Barton AK, Stadler P, Ohnesorge B. Effect of head and neck position on pharyngeal diameter in horses.. Vet Radiol Ultrasound 2010 Sep-Oct;51(5):491-7.
- Linford RL, O'Brien TR, Wheat JD, Meagher DM. Radiographic assessment of epiglottic length and pharyngeal and laryngeal diameters in the Thoroughbred.. Am J Vet Res 1983 Sep;44(9):1660-6.
- FEI. Dressage Rules 2014. Rules for Dressage.. .
- FEI. Report of the FEI Veterinary and Dressage Committees’ Workshop. The use of over bending (“Rollkur”) in FEI Competition.. 31 January 2006 during the FEI Veterinary Committee meeting at the Olympic Museum, Lausanne.
- FEI. FEI Stewards Manual DressageNew Annex XIII. Pre and Post Competition training techniques - position of the horse’s head - stretching. .
- Go LM, Barton AK, Ohnesorge B. Objective classification of different head and neck positions and their influence on the radiographic pharyngeal diameter in sport horses.. BMC Vet Res 2014 May 23;10:118.
- Faul F, Erdfelder E, Lang AG, Buchner A. G*Power 3: a flexible statistical power analysis program for the social, behavioral, and biomedical sciences.. Behav Res Methods 2007 May;39(2):175-91.
- Gehlen H, Zebisch A, Schutte A, Oel C, May A. Overground exercise endoscopy of upper airways in standardbreds, thoroughbreds and warmblood riding horses under normal training conditions.. Pferdeheilkd 2010;26:344–352.
- Pollock PJ, Reardon RJM. Dynamic respiratory endoscopy without a treadmill: Initial experiences.. Equine Veterinary Education 2009;21:367–370.
- Tamzali Y, Serraud N, Baup B, Desmaizieres LM. How to perform endoscopy during exercise without a treadmill.. Proc Am Ass Equine Practnrs 2008;54:24–28.
- Van Erck E. Dynamic respiratory videoendoscopy in ridden sport horses: effect of head flexion, riding and airway inflammation in 129 cases.. Equine Vet J Suppl 2011 Nov;(40):18-24.
- Strand E, Fjordbakk CT, Holcombe SJ, Risberg A, Chalmers HJ. Effect of poll flexion and dynamic laryngeal collapse on tracheal pressure in Norwegian Coldblooded Trotter racehorses.. Equine Vet J 2009 Jan;41(1):59-64.
- Petsche VM, Derksen FJ, Berney C, Robinson NE. Effect of head position on upper airway function in exercising horses.. Equine Vet J 1995;27:18–22.
- Hanche-Olsen S. Bilateral dynamic laryngeal collapse associated with collection in high poll flexion in a gaited Icelandic horse.. Pferdeheilkd 2010;26:810–813.
- Gerring EL. Differential diagnosis of equine respiratory noises.. In Pract 1985 Jul;7(4):109-17.
- Boyle AG, Martin BB Jr, Davidson EJ, Durando MM, Birks EK. Dynamic pharyngeal collapse in racehorses.. Equine Vet J Suppl 2006 Aug;(36):546-50.
- Allen KJ, Lane JG, Woodford NS, Franklin SH. Severe collapse of the rostral soft palate as a source of abnormal respiratory noise in six ponies and horses.. Equine Vet J 2007 Nov;39(6):562-6.
- Tessier C, Holcombe SJ, Derksen FJ, Berney C, Boruta D. Effects of stylopharyngeus muscle dysfunction on the nasopharynx in exercising horses.. Equine Vet J 2004 May;36(4):318-23.
- Holcombe SJ, Derksen FJ, Berney C, Becker AC, Horner NT. Effect of topical anesthesia of the laryngeal mucosa on upper airway mechanics in exercising horses.. Am J Vet Res 2001 Nov;62(11):1706-10.
Citations
This article has been cited 3 times.- Martins NA, Fonseca BPA, Silvatti AP, Valente FL, Soares NL, Simonato SP, Rosa LP, Andrade MO, Barcelos KMDC. Head and Neck Positions Affect Equine Kinematic Variables in Marcha Batida Gait-A Pilot Study. Animals (Basel) 2025 Apr 9;15(8).
- König von Borstel U, Kienapfel K, McLean A, Wilkins C, McGreevy P. Hyperflexing the horse's neck: a systematic review and meta-analysis. Sci Rep 2024 Oct 2;14(1):22886.
- Scholler D, Wittenberg J, Zablotski Y, May A. Do tight nosebands have an effect on the upper airways of horses?. Vet Med Sci 2024 Jul;10(4):e1478.
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