{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,13]],"date-time":"2026-03-13T16:58:46Z","timestamp":1773421126102,"version":"3.50.1"},"reference-count":45,"publisher":"American Veterinary Medical Association (AVMA)","issue":"5","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["ajvr"],"published-print":{"date-parts":[[2008,5]]},"abstract":"<jats:title>Abstract<\/jats:title>\n<jats:p><jats:bold>Objective<\/jats:bold>\u2014To determine the phase and quantitate the electromyographic (EMG) activity of the genioglossus, geniohyoideus, hyoepiglotticus, omohyoideus, sternohyoideus, sternothyroideus, and thyrohyoideus muscles of clinically normal horses during strenuous exercise.<\/jats:p>\n<jats:p><jats:bold>Animals<\/jats:bold>\u20147 clinically normal adult horses (2 Thoroughbreds and 5 Standardbreds).<\/jats:p>\n<jats:p><jats:bold>Procedures<\/jats:bold>\u2014Bipolar electrodes were surgically implanted in the aforementioned muscles, and horses were subjected to an incremental exercise test on a high-speed treadmill. The EMG, heart rate, respiratory rate, and static pharyngeal airway pressures were measured during exercise. The EMG was measured as mean electrical activity (MEA). The MEA values for maximal exercise intensity (13 or 14 m\/s) were expressed as a percentage of the MEA measured at an exercise intensity of 6 m\/s.<\/jats:p>\n<jats:p><jats:bold>Results<\/jats:bold>\u2014MEA was detected during expiration in the genioglossus, geniohyoideus, sternohyoideus, and thyrohyoideus muscles and during inspiration in the hyoepiglotticus and sternothyroideus muscles. Intensity of the MEA increased significantly with exercise intensity in the genioglossus, geniohyoideus, and hyoepiglotticus muscles. Intensity of the MEA increased significantly in relation to expiratory pharyngeal pressure in the geniohyoideus and hyoepiglotticus muscles.<\/jats:p>\n<jats:p><jats:bold>Conclusions and Clinical Relevance<\/jats:bold>\u2014Once exercise intensity reached 6 m\/s, no quantifiable additional increase in muscular activity was detected in the omohyoideus, sternohyoideus, sternothyroideus, and thyrohyoideus muscles. However, muscles that may affect the diameter of the oropharynx (genioglossus and geniohyoideus muscles) or rima glottis (hyoepiglotticus muscle) had activity correlated with the intensity of exercise or expiratory pharyngeal pressures. Activity of the muscles affecting the geometry of the oropharynx may be important in the pathophysiologic processes associated with nasopharyngeal patency.<\/jats:p>","DOI":"10.2460\/ajvr.69.5.682","type":"journal-article","created":{"date-parts":[[2008,5,1]],"date-time":"2008-05-01T11:55:00Z","timestamp":1209642900000},"page":"682-689","source":"Crossref","is-referenced-by-count":11,"title":["Activity of selected rostral and caudal hyoid muscles in clinically normal horses during strenuous exercise"],"prefix":"10.2460","volume":"69","author":[{"given":"Samantha L.","family":"Morello","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Norm G.","family":"Ducharme","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Richard P.","family":"Hackett","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lorin D.","family":"Warnick","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lisa M.","family":"Mitchell","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"L. 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palate function in horses","volume":"59","author":"Holcombe","year":"1998"},{"key":"ref5","series-title":"Equine Vet J","first-page":"232","article-title":"Electromyographic activity of the stylopharyngeus muscle in exercising horses","volume":"37","author":"Tessier","year":"2005"},{"key":"ref6","series-title":"Am J Vet Res","first-page":"1022","article-title":"Effects of bilateral hypoglossal and glossopharyngeal nerve blocks on epiglottic and soft palate position in exercising horses","volume":"58","author":"Holcombe","year":"1997"},{"key":"ref7","series-title":"Sisson and Grossman's the anatomy of the domestic animals. 5th ed","first-page":"376","article-title":"Equine myology","author":"Sisson","year":"1975"},{"key":"ref8","series-title":"Dysphagia","doi-asserted-by":"publisher","first-page":"58","DOI":"10.1007\/s00455-002-0082-3","article-title":"Role of the pharyngeal branch of the vagus nerve in laryngeal elevation and UES pressure during swallowing in rabbits","volume":"18","author":"Fukushima","year":"2003"},{"key":"ref9","series-title":"J Appl Physiol","doi-asserted-by":"publisher","first-page":"2812","DOI":"10.1152\/jappl.1994.77.6.2812","article-title":"Effect of sternothyrohyoid myectomy on upper airway mechanics in normal horses","volume":"77","author":"Holcombe","year":"1994"},{"key":"ref10","series-title":"Am J Vet Res","doi-asserted-by":"publisher","first-page":"1617","DOI":"10.2460\/ajvr.2002.63.1617","article-title":"Electromyographic activity of the hyoepiglotticus muscle and control of epiglottis position in horses","volume":"63","author":"Holcombe","year":"2002"},{"key":"ref11","series-title":"Arch Otolaryngol Head Neck Surg","doi-asserted-by":"publisher","first-page":"1361","DOI":"10.1001\/archotol.1995.01890120021004","article-title":"The effects of selective nerve stimulation on upper airway airflow mechanics","volume":"121","author":"Eisele","year":"1995"},{"key":"ref12","series-title":"Am J Vet Res","doi-asserted-by":"publisher","first-page":"1865","DOI":"10.2460\/ajvr.2001.62.1865","article-title":"Computed tomographic study of the effect of a tongue-tie on hyoid apparatus position and nasopharyngeal dimensions in anesthetized horses","volume":"62","author":"Cornelisse","year":"2001"},{"key":"ref13","series-title":"J Appl Physiol","doi-asserted-by":"publisher","first-page":"197","DOI":"10.1152\/jappl.1984.57.1.197","article-title":"Respiratory function of hyoid muscles and hyoid arch","volume":"57","author":"Van de Graff","year":"1984"},{"key":"ref14","series-title":"Respir Physiol","doi-asserted-by":"publisher","first-page":"159","DOI":"10.1016\/0034-5687(96)00028-X","article-title":"Electromyographic activity of the hyoepiglotticus muscle in dogs","volume":"104","author":"Amis","year":"1996"},{"key":"ref15","series-title":"Respir Physiol","doi-asserted-by":"publisher","first-page":"179","DOI":"10.1016\/0034-5687(96)00030-8","article-title":"Influence of hyoepiglotticus muscle contraction on canine upper airway geometry","volume":"104","author":"Amis","year":"1996"},{"key":"ref16","series-title":"J Appl Physiol","doi-asserted-by":"publisher","first-page":"1657","DOI":"10.1152\/japplphysiol.00348.2006","article-title":"The effect of surface electrical stimulation on hyolaryngeal movement in normal individuals at rest and during swallowing","volume":"101","author":"Humbert","year":"2006"},{"key":"ref17","series-title":"Respir Physiol","doi-asserted-by":"publisher","first-page":"87","DOI":"10.1016\/0034-5687(83)90018-X","article-title":"Activity of upper airway muscles during augmented breaths","volume":"53","author":"van Lunteren","year":"1983"},{"key":"ref18","series-title":"J Appl Physiol","doi-asserted-by":"publisher","first-page":"210","DOI":"10.1152\/jappl.1988.65.1.210","article-title":"Upper airway pressure receptors alter expiratory muscle EMG and motor unit firing","volume":"65","author":"van Lunteren","year":"1988"},{"key":"ref19","series-title":"J Appl Physiol","first-page":"15","article-title":"Evidence for reflex upper airway dilator muscle activation by sudden negative airway pressure in man","volume":"436","author":"Horner","year":"1991"},{"key":"ref20","series-title":"J Appl Physiol","first-page":"31","article-title":"Afferent pathway(s) for pharyngeal dilator reflex to negative pressure in man: a study using upper airway anesthesia","volume":"436","author":"Horner","year":"1991"},{"key":"ref21","series-title":"J Appl Physiol","doi-asserted-by":"publisher","first-page":"2242","DOI":"10.1152\/jappl.1991.70.5.2242","article-title":"Pressure-diameter relationships of the upper airway in awake supine subjects","volume":"70","author":"Wheatley","year":"1991"},{"key":"ref22","series-title":"J Appl Physiol","doi-asserted-by":"publisher","first-page":"1614","DOI":"10.1152\/jappl.1983.55.5.1614","article-title":"Effects of hypercapnia and hypoxia on abdominal expiratory nerve activity","volume":"55","author":"Ledlie","year":"1983"},{"key":"ref23","series-title":"Am J Respir Crit Care Med","doi-asserted-by":"publisher","first-page":"606","DOI":"10.1164\/rccm.200502-190OC","article-title":"Reversibility of airflow obstruction by hypoglossus nerve stimulation in anesthetized rabbits","volume":"172","author":"Bellemare","year":"2005"},{"key":"ref24","series-title":"Otolaryngol Clin North Am","doi-asserted-by":"publisher","first-page":"501","DOI":"10.1016\/S0030-6665(02)00178-0","article-title":"Tongue neuromuscular and direct hypoglossal nerve stimulation for obstructive sleep apnea","volume":"36","author":"Eisele","year":"2003"},{"key":"ref25","series-title":"Am J Respir Crit Care Med","doi-asserted-by":"publisher","first-page":"455","DOI":"10.1164\/ajrccm.151.2.7842206","article-title":"Hypoglossal nerve stimulation affects the pressure-volume behavior of the upper airway","volume":"151","author":"Hida","year":"1995"},{"key":"ref26","series-title":"Arch Otolaryngol Head Neck Surg","doi-asserted-by":"publisher","first-page":"1216","DOI":"10.1001\/archotol.127.10.1216","article-title":"Therapeutic electrical stimulation of the hypoglossal nerve in obstructive sleep apnea","volume":"127","author":"Schwartz","year":"2001"},{"key":"ref27","series-title":"J Appl Physiol","doi-asserted-by":"publisher","first-page":"1377","DOI":"10.1152\/japplphysiol.00379.2006","article-title":"Anatomic consequences of intrinsic tongue muscle activation","volume":"101","author":"Bailey","year":"2006"},{"key":"ref28","series-title":"Tex Rep Biol Med","first-page":"444","article-title":"Electromyographic activity of intrinsic and extrinsic muscles of the human tongue","volume":"33","author":"Sauerland","year":"1975"},{"key":"ref29","series-title":"J Comp Neurol","doi-asserted-by":"publisher","first-page":"376","DOI":"10.1002\/cne.903570305","article-title":"Differential innervation of protruder and retractor muscles of the tongue in rat","volume":"357","author":"Dobbins","year":"1995"},{"key":"ref30","series-title":"Am J Respir Crit Care Med","doi-asserted-by":"publisher","first-page":"287","DOI":"10.1164\/rccm.2104120","article-title":"Adaptation of upper airway muscles to chronic endurance exercise","volume":"166","author":"Vincent","year":"2002"},{"key":"ref31","series-title":"J Appl Physiol","doi-asserted-by":"publisher","first-page":"2023","DOI":"10.1152\/japplphysiol.00203.2003","article-title":"Upper airway response to electrical stimulation of the genioglossus in obstructive sleep apnea","volume":"95","author":"Oliven","year":"2003"},{"key":"ref32","series-title":"J Appl Physiol","doi-asserted-by":"publisher","first-page":"931","DOI":"10.1152\/jappl.1978.44.6.931","article-title":"Pathogenesis of upper airway occlusion during sleep","volume":"44","author":"Remmers","year":"1978"},{"key":"ref33","series-title":"Am Rev Respir Dis","doi-asserted-by":"publisher","first-page":"597","DOI":"10.1164\/ajrccm\/148.3.597","article-title":"Influence of sleep on genioglossus muscle activation by negative pressures in normal men","volume":"148","author":"Wheatley","year":"1993"},{"key":"ref34","series-title":"Eur Respir J","first-page":"1537","article-title":"Electrically-activated dilator muscles reduce pharyngeal resistance in anaesthetized dogs with upper airway obstruction","volume":"8","author":"Bishara","year":"1995"},{"key":"ref35","series-title":"J Physiol","doi-asserted-by":"publisher","first-page":"677","DOI":"10.1111\/j.1469-7793.2001.0677h.x","article-title":"Phasic mechanoreceptor stimuli can induce phasic activation of upper airway muscles in humans","volume":"531","author":"Akahoshi","year":"2001"},{"key":"ref36","series-title":"J Appl Physiol","doi-asserted-by":"publisher","first-page":"772","DOI":"10.1152\/jappl.1979.46.4.772","article-title":"A neuromuscular mechanism maintaining extrathoracic airway patency","volume":"46","author":"Brouillete","year":"1979"},{"key":"ref37","series-title":"J Appl Physiol","doi-asserted-by":"publisher","first-page":"2600","DOI":"10.1152\/jappl.1994.77.6.2600","article-title":"Soft palate muscle activity in response to hypoxic hypercapnia","volume":"77","author":"Van der Touw","year":"1994"},{"key":"ref38","series-title":"J Appl Physiol","doi-asserted-by":"publisher","first-page":"1761","DOI":"10.1152\/japplphysiol.01142.2004","article-title":"Episodic hypoxia induces long-term facilitation of neural drive to tongue protrudor and retractor muscles","volume":"98","author":"Fuller","year":"2005"},{"key":"ref39","series-title":"J Anat","first-page":"1","article-title":"Intrinsic fibre architecture and attachments of the human epiglottis and their contributions to the mechanism of deglutition","volume":"186","author":"VanDaele","year":"1995"},{"key":"ref40","series-title":"J Appl Physiol","doi-asserted-by":"publisher","first-page":"1010","DOI":"10.1152\/jappl.1992.72.3.1010","article-title":"Contractile properties of feline genioglossus, sternohyoid, and sternothyroid muscles","volume":"72","author":"van Lunteren","year":"1992"},{"key":"ref41","series-title":"Sleep Med","doi-asserted-by":"publisher","first-page":"497","DOI":"10.1016\/j.sleep.2005.03.007","article-title":"The anatomic basis for the acquisition of speech and obstructive sleep apnea: evidence from cephalometric analysis supports The Great Leap Forward hypothesis","volume":"6","author":"Davidson","year":"2005"},{"key":"ref42","series-title":"Am J Respir Crit Care Med","doi-asserted-by":"publisher","first-page":"664","DOI":"10.1164\/rccm.200301-092OC","article-title":"Genioglossus activity in children with obstructive sleep apnea during wakefulness and sleep onset","volume":"168","author":"Katz","year":"2003"},{"key":"ref43","series-title":"Am J Respir Crit Care Med","doi-asserted-by":"publisher","first-page":"2025","DOI":"10.1164\/ajrccm.164.11.2102048","article-title":"Genioglossal activation in patients with obstructive sleep apnea versus control subjects. Mechanisms of muscle control","volume":"164","author":"Fogel","year":"2001"},{"key":"ref44","series-title":"Am J Respir Crit Care Med","doi-asserted-by":"publisher","first-page":"163","DOI":"10.1164\/rccm.200304-590OC","article-title":"Increased upper airway collapsibility in children with obstructive sleep apnea during wakefulness","volume":"169","author":"Gozal","year":"2004"},{"key":"ref45","series-title":"Am J Respir Crit Care Med","doi-asserted-by":"publisher","first-page":"902","DOI":"10.1164\/rccm.200509-1450OC","article-title":"Influence of airway pressure on genioglossus activity during sleep in normal children","volume":"173","author":"Katz","year":"2006"}],"container-title":["American Journal of Veterinary Research"],"original-title":[],"link":[{"URL":"https:\/\/avmajournals.avma.org\/view\/journals\/ajvr\/69\/5\/ajvr.69.5.682.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/avmajournals.avma.org\/downloadpdf\/journals\/ajvr\/69\/5\/ajvr.69.5.682.xml","content-type":"text\/html","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/avmajournals.avma.org\/downloadpdf\/journals\/ajvr\/69\/5\/ajvr.69.5.682.xml","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,3,7]],"date-time":"2025-03-07T12:47:38Z","timestamp":1741351658000},"score":1,"resource":{"primary":{"URL":"https:\/\/avmajournals.avma.org\/view\/journals\/ajvr\/69\/5\/ajvr.69.5.682.xml"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2008,5]]},"references-count":45,"journal-issue":{"issue":"5"},"URL":"https:\/\/doi.org\/10.2460\/ajvr.69.5.682","relation":{},"ISSN":["0002-9645"],"issn-type":[{"value":"0002-9645","type":"print"}],"subject":[],"published":{"date-parts":[[2008,5]]}}}