Dr. Russell MacKechnie-Guire
January 2021
There is a growing awareness, both scientifically and on social media on the effect that noseband fit, and tightness can have on equine welfare. Whilst this is a positive step forward there is very little consideration for the effect that the rest of the bridle can have on equine welfare, comfort and performance.
The anatomy must be considered when fitting bridles, the bridle has to conform and sit over anatomical structures, various nerves etc. which can influence locomotion, swallowing mechanism, proprioception and function. The fit of the bridle (as a unit) can have a direct effect on equine welfare, comfort and performance. In the context of the headpiece, it is often thought that bridles cause “poll” pressure. Using a validated pressure mat (middle image) beneath the headpiece we have demonstrated (1) that there is pressure over the head but that this pressure is not excessively high. Instead areas of high pressures beneath the headpiece were localised at the base of the ears, in the region of the temporomandibular joint (TMJ) a sensitive area with complex nerve arrangements and articulation between the mandible and the skull.
Structurally, not all horses’ heads are the same shape so bridles should be fitted to individual horses. Headpiece width and design should be considered, a straight narrow headpiece can run forward putting pressure on the cartilage of the ears, likewise a headpiece which is too wide can put pressure on the wing of the atlas (L and R) empathising the need for bridle fit for each horse.
Headpiece design and noseband straps which are positioned underneath the headpiece can create a ridge of pressure over the head (Image A), by using a modified headpiece which is shaped, padded and where the noseband attaches either side, this ridge of pressure can be eliminated (Image B.) (1).
Buckles which are positioned over the head, or to one side of the midline, can result in focal pressures beneath the buckles. In respect of browbands, riders can express themselves with various colours or stones however, we must not neglect the fit. In some cases, the browband is fixed or can slide up and down the cheek/headpiece. In the case where the browband can slide up and down, at this junction, areas of high pressures may occur due to the ridge running under the headpiece. Likewise, a browband which is too small, can pull the headpiece forward, (into the back of the ears) creating areas of high pressure.
In trot peak pressures beneath the headpiece occur soon after midstance (75% of stance) for both diagonal support phases. The magnitude of pressure is directly influenced by the fit and design of the headpiece and attachment and fit of the browband. Meaning that every time the horse loads its limbs (every stride), wearing a headpiece and/or browband which is incorrectly fitted could cause areas of high pressure beneath the headpiece, every stride. The bridle should be considered as a unit and we must not underestimate the effect that the bridle (as a unit) can have on the horse. In respect of locomotion, when pressures were reduced beneath the bridle, an increase in carpal, tarsal flexion and limb protraction was reported (1). From unpublished data (3), back range of motion is also influenced by bridle fit and design this highlights the direct connection between bridle fit and whole horse biomechanics. In swimming, swimmers have been reported to suffer from supraorbital neuralgia (pain above the eye) headaches (2), this is thought to be due to the tightness of the goggles. Although we cannot confirm this is the case in horses, cautiously applying similar principles, we should not underestimate the effect that incorrect headpiece and browband fit can have on equine welfare, comfort, and performance similar to the effect that that noseband fit and tightness can have. What we have found is horses will develop a locomotor strategy to compensate and alleviate any discomfort, therefore correct bridle fit (and saddle fit) is essential.
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1. Murray R, Guire R, Fisher M, Fairfax V. A Bridle Designed to Avoid Peak Pressure Locations Under the Headpiece and Noseband Is Associated With More Uniform Pressure and Increased Carpal and Tarsal Flexion, Compared With the Horse's Usual Bridle. Journal of Equine Veterinary Science. 2015;35(11-12):947-55.
2. O'Brien J. C. J. Swimmer's headache, or supraorbital neuralgia. . Proceedings (Baylor University Medical Center). 2004;17(4: 418–9.
3. MacKechnie-Guire et al 2018 - unpublished