Effects of different head-neck positions on the larynges of ridden horses.
Authors: Zebisch A, May A, Reese S, Gehlen H
Journal: Journal of animal physiology and animal nutrition
Summary
# Editorial Summary: Head-Neck Position and Laryngeal Function in Ridden Horses Hyperflexion—the extreme poll and neck flexion commonly employed in ridden training—has drawn welfare concerns, yet objective evidence of its physiological effects remained limited. Zebisch and colleagues used transendoscopic video analysis to directly visualise the larynges of 14 horses at rest and during three distinct postural phases: stretching, working position, and hyperflexion, quantifying changes in laryngeal dimensions across these conditions. Hyperflexion produced significant laryngeal compression compared to the working position, with the laryngeal opening area reducing by approximately 8.2%, alongside diminished function in other laryngeal parameters; these changes occurred consistently regardless of horse age, training level, or individual anatomical variation. The findings provide direct anatomical evidence that hyperflexion substantially narrows the upper airway, with potential implications for respiratory efficiency and exercise performance. Farriers and trainers should consider these mechanical constraints when assessing ridden postures, particularly for performance horses where even modest reductions in laryngeal patency may compromise oxygen delivery during intense work.
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Practical Takeaways
- •Hyperflexion training positions substantially compress the larynx and restrict upper airway patency, potentially compromising respiratory function and horse welfare regardless of individual variation
- •The consistent laryngeal compression during hyperflexion across all horse types suggests this is an inherent biomechanical effect of the head-neck position, not related to training or conformation
- •Riding instructors and trainers should reconsider hyperflexion techniques given the documented airway restriction, particularly for performance horses requiring maximal respiratory capacity
Key Findings
- •Hyperflexion causes significant reduction in laryngeal opening area of 8.2 ± 5.0% compared to working position (p = 0.001)
- •Laryngeal compression during hyperflexion was independent of horse age, education level, and individual anatomical poll-neck conditions
- •Multiple laryngeal parameters showed significant diminishment during hyperflexion beyond the primary opening area reduction