The purpose of the Slypner Athletic Horseshoe System is to protect the horse's locomotive system and, at the same time, to ensure the optimum freedom of movement. In order to reach this goal it has been necessary to undertake thorough studies of the hoof and of the locomotive system of the horse that is concerned with its movement.

The interchangeable wearing sole is an essential part of what makes Slypner Athletic Horseshoes so unique. The wearing sole is physically flexible, obviously, but it also offers you, the rider or trainer, more flexibility in attending to your horse's shoeing needs.

The Hoof

The fore and hind hooves differ from each other in that the fore hoof's undersurface is rounder than the more pointed (triangular) shape of the hind hooves. In both the front and hind hooves the horn wall is thickest at the toe, gradually decreasing towards the heel. Also, the horn wall is thicker on the outside wall of the hoof than on the inside wall. At the quarters of the hoof the horn wall is almost at right angles to the sole, whereas the angle at the toe is 45-55 degrees.

The new horn, which the hoof grows all the time, is produced in the coronary band or coronary corium, which surrounds the hoof where hair growth and hoof meet. The new layer of horn, which is quite soft, pushes the old horn layer downwards.

The horny sole grows from the inside and out, forcing the outer layer, the oldest horn, to shell away (exfoliation).

The horn of the hoof is both hard and tough, though the hardness varies much in the different areas of the hoof. It is hardest at the toe, where it is the oldest, and it is toughest at the heel, where the horn has the most expansion and contraction. The front part of the hoof is thus suitable for fastening the shoe to, because here the horn is hard and possesses very little movement.

The hoof is flexible from the quarters of the hoof and backwards towards the heel, since the horn in this area moves transversely during locomotion.

The elasticity of the horny mass of the hoof can be likened to a pumping station, whose effect is to increase the blood and food supply to the hoof and so helps to increase the supply of nutrition to the hoof. Furthermore, large movements in the hoof lead to the secretion of a liquid whose function is to lubricate the inner surface of the hoof.

The expansion and contraction in the hoof act as the horse's natural shock absorber, and it is very important that this play can occur freely and without hindrance. The principle that the hoof can move and change its shape with changes in load has, at the same time, great meaning for the health of the hoof and the quality of its horn.

During locomotion, the horse's legs are exposed to great strain when the horse's hooves strike the ground. In order to prevent injury caused by the hooves striking the ground, the best possible expansion and contraction in the hoof must be ensured. Additionally, the strain on the deep digital flexor tendon, during breakover, must be relieved.

When the horse is moving quickly and thus putting great strain on its locomotive system, it can be very difficult to see how the hoof moves. There are also variations from horse to horse. But it is always the case that the natural movement of the hoof becomes more distinct the faster the horse moves.

The fetlock is slightly bent when the heels of the hoof hit the ground. In order to protect the horse's locomotive system from the large stresses that occur during this down stroke, the hoof has its own built in shock absorber. This natural shock absorber consists of the elastic tissue structures of the heels, the lateral cartilage, and the digital cushion, together with the Wshape of the frog. These structures allow for a very rapid transverse change in shape, extending the impact time and thus reducing the large concussion that occurs during the down stroke. The concussion, and thus the strain on the locomotive system, increases with speed or with the height of a jump.

Before the horse can move off, it must keep its hoof still on the ground. In order for this to be possible it is necessary for the fetlock to undergo a large movement. The fetlock must allow the horse's body to undergo the forward movement, and at the same time transfer both the weight of the horse and its rider to the ground. In addition, the fetlock needs to bend so as to produce the acute angle B, since the later moving off takes place by straightening and stretching the fetlock. In order for the fetlock to undertake this movement it must move downwards towards the ground N.

In this phase, when the fetlock moves downward towards the ground to produce the fetlock angle B the horse's weight imposes more and more strain on the digital cushion and, as a consequence, the heels are pushed outwards as a step in a pattern of movement. That the hoof remains stationary is clear from the hoofprint made on the track. This hoofprint clearly shows that the whole of the load is transferred to the ground. When the horse moves off or accelerates, the fetlock is stretched. At the same time it rotates over the toe of the hoof breakover.

If the joints are overstressed, the formation of galls can occur. Galls are the overproduction of synovial fluid, which usually collects as a cushion around the overstressed joint.

The fetlock is the joint most prone to the formation of galls. If the tendons are overstressed they swell and become tender. It is easy to investigate if they have been injured, by pressing on them. Those tendons that are most often affected by this injury are those just above the fetlock, especially the deep digital flexor tendon, since this is subject to great stress, both in moving through and in breakover. This tendon is responsible for carrying almost the entire load.

The deep digital flexor tendon can be protected from damage by angling the toe of the shoe. This aids the horse in breakover. However, if this angling is to have any effect, it must take place in such a way that the shoe can rotate about a point that lies behind the white line under the horse's toe.