Evaluation of Dynamic Structural Disorders in the Upper Airways and Applied Rein Tension in Healthy Dressage Horses During Riding in Different Gaits and Head-Neck Positions.

The research uses endoscopy and rein tension measurement on 13 healthy dressage horses to assess how different gaits and head-neck positions (HNPs), namely ‘unrestrained’, ‘competition frame’, ‘hyperflexion‘, and ‘low-deep-round’, influence the structure and health of their upper airways. It finds that the ‘low-deep-round’ position is less forceful and may be healthier, though more research is required to fully ascertain the effects of flexion on airway structure.

Study Methodology

• This study was conducted with 13 clinically fit and high-performing Warmblood dressage horses.
• The horses were put through a standardized program covering four different gaits: halt, walk, trot, and canter.
• The horses were also ridden in four different Head-Neck Positions (HNPs): unrestrained, competition frame, hyperflexion, and low-deep-round.
• Rein tension was measured, and the upper airways of the horses were evaluated using Overground Endoscopy (OGE) during these gaits and HNPs.

Results and Findings

• All included horses were able to achieve the desired HNPs.
• The low-deep-round HNP showed significantly lower rein tension than both the competition frame and hyperflexion (proven statistically significant with P values less than .001 in both cases).
• An association was found between dynamic structural disorders in the upper airway tract, as evaluated by OGE, and head-neck flexion.
• The severity of the dynamic structural disorders in the upper airway was however not linked to the degree of flexion.
• The hyperflexion HNP was neither associated with greater rein tension nor with severe dynamic structural disorders compared to the competition frame HNP.

Conclusions and Recommendations

• Results from the study confirm that the low-deep-round HNP is a nonforced position. This is in contrast to hyperflexion, which is a forced position according to the standards set by the Fédération Equestre Internationale.
• The study recommends further research to evaluate whether dynamic structural disorders are a result of flexion or if the degree of flexion has an actual impact.