Research is proving that bridle pressure can inhibit a horse’s performance, but what’s key to a perfect fit? Dr Rachel Murray MRCVS explains
RECENT developments in technology are enabling us to understand more about the effects of the bridle. Investigations using under-bridle pressure mats are revealing that bridle design and fit can significantly affect a horse’s movement pattern – and therefore his ability to perform.
The nature of equine anatomy means that certain areas of the head are vulnerable to pressure. The better the design and fit of the bridle, the lower the pressure in these areas and the fewer the locations where pressure points can be seen.
At the sites where pressure does occur, this is unlikely to be continuous and will vary depending on the point in the stride. Additionally, depending
on the position of the horse’s head, the location of maximal pressure can vary.
When a horse’s head is more vertical, for example, greater pressure tends to occur at the top edge of the noseband (nearest the eyes). Pressure is more likely to occur under the bottom edge when the head is more horizontal.
Pressures are usually higher during faster paces, or when movement is more extravagant, meaning that good bridle fit and design are especially important for the performance horse. However, pressure points can occur with any horse, whatever his job, so the bridle must be fitted and checked as carefully as the saddle.
THE more stable a bridle is on a horse’s head, the less likely he is to experience pressure points at the front and back of the headpiece, or rubs at the corners of his mouth as the bit moves.
Some “give” is needed in the noseband, however, as the head moves. Since the noseband is attached over the top of the head, it can act as a fixed unit; this can then create pressure points on the poll and also underneath the horizontal fitting, particularly if done up tightly.
It is important that the noseband is not too tight or fastened with the horizontal part too high. There should be space between the noseband and the facial crest. Side rings, such as those typically seen on a drop or crank noseband, allow the noseband to move better with the horse’s head and can help reduce pressure under both the noseband and headpiece.
Pressure points are likely to occur under buckles or metal fittings, particularly if these are located over the higher-risk locations. These fastenings should be positioned carefully and padded where possible. Stiff material or hard edges can also create pressure points and are better avoided. A rolled or narrow noseband strap under the headpiece can localise pressure over the poll, so needs to be carefully checked.
A number of higher-risk locations involve the headpiece: at the front, where it pushes against the base of the ears; at the back, where it impacts against the wings of the atlas; and underneath, on the top of the poll.
Additional risk areas are situated underneath or close to the browband attachments (pressure points can occur here when the horse swallows, or moves his tongue or jaw); under the noseband, on either side of the nasal bone; and over the jawbones on the underside of the chin.
THE fit of a bridle is affected by a horse’s conformation. Few horses have a symmetrical head, so the shape and fit on one side may need to be different to the other.
The distance between the corner of the mouth and the facial crest can vary. A horse with a long mouth and a low facial crest will have a very short distance to accommodate a noseband, so a wide noseband can create real problems – especially if he has thick skin, which can become bunched up between the bit and the noseband and cause rubs or pinching.
Careful selection of the noseband width and shape, choosing a design that narrows at the sides, for example, is critical if there is limited space.
Generally, a wider headpiece over the top of the head reduces pressures over the midline of the poll, although the distance between the back of the ears and the wings of the atlas can vary between horses. If the atlas is positioned close to the back of the ears, there is very little space.
For horses with this type of anatomy, narrowing of the headpiece at the sides may reduce pressure points at the front and back and improve both comfort and performance. This is particularly important if the horse has a large crest, which can cause the bridle to fly forward over the ears, or is ridden in a curb bit with long shanks – where the headpiece is more likely to be pushed against the back of the ears.
The height of the browband and cheekpiece buckles needs to be assessed relative to the bony prominences below the ears. The browband should be long enough, and the headpiece of sufficient length that the browband does not sit too high.
The padding on a noseband should be wide enough under the jaw or over the nose to limit pressure points on these bony edges. If a horse has a wide jaw, the length of the padding should be assessed in relation to his shape and size. Some horses have a longer distance over the top of the nose to the mouth, while others have a bigger chin; where possible, consider the individual and tailor the bridle shape and size to his conformation.
When a bitless bridle is used, the positioning and shape of a bridle over the horse’s nose is even more important, as pressures created at this location may be much greater than with a standard noseband.
SPOTTING THE SIGNS
STUDIES have shown that high pressures under the bridle reduce the quality of a horse’s movement, both limb flexion and stride pattern. By selecting bridle fit and design to suit the anatomy of the individual, these pressures can be avoided and performance will be improved.
Signs of discomfort range from a dislike of being tacked up or handled around the ears and an unwillingness to go forwards, to head tossing or ear drooping on one side during ridden exercise. More obvious indications include white hairs at pressure points, rubbing on the corners of the mouth or the cheeks, or a swelling or indentation over the nasal or jawbones.
Extra padding is not necessarily the answer, since this can make the bridle more unstable and lead to problems elsewhere. Consulting a Society of Master Saddlers-trained bridle-fitter will be worthwhile if problems persist.
Identifying pressure zones
THE head comprises large areas where there is limited soft tissue covering the bone, leading to anatomical prominences and moving parts with little padding. The shape and location of these can create pressure points under the bridle.
The numerous nerves and blood vessels that run over and around the bony prominences are at risk of irritation or injury, if the shape and fit of the bridle is not optimal.
Key areas of interference include:
● The edges of the nasal bone.
● Under the mandible (lower jaw).
● Bony enlargements around the roots of the teeth – a particular problem in the young horse.
● The facial crest – the bone that sits under the cheekpiece and above the noseband.
● The temporomandibular joint and hyoid apparatus, which move with the jaw and tongue motion.
● The skull, which is quite pointed at the poll.
● Behind the ears; while this area does have muscle coverage, space is limited by the bony side wings of the atlas (the first neck vertebra).
You can also read this feature in the 20 May issue of Horse & Hound magazine.
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