The hind quarters carry 40% of a horse's body weight which is mostly made up of muscle and bone which is the horse's engine or its power house and in the wild, feral horses rely on this to propel them at speed from any danger or to kick out in the act of defence. It is this power that man has harnessed in domesticating the horse - power to pull heavy loads and the speed to transport themselves and us from point A to B.

To understand this clever structure, we must first look at the movement of the hind leg. This starts with the limb coming forward just slightly heel landing to absorb the concussion and landing in the hoof print of the front foot. This is known as tracking-up and is a movement horses can do even if the hind limb is not working at its optimum ability. Once the weight of the horse moves over the limb, we get to the weight bearing part of the action, when the bones of the leg are bearing the weight of the horse and the frog is pushed up into the digital cushion. This applies pressure onto the lateral cartilages that run either side of the pedal bone and attach to both the side and the front of the pedal bone and to the bottom of the short pastern.

During this weight bearing phase, if the frog is working properly, i.e. pushing up into the digital cushion, these bones are lifted up and forward and this puts them into the correct position for the power phase of the stride. This is when the leg moves from a vertical position to out behind, thus thrusting the horse forward and it is this part of the movement that is missing in many horses.

When the power phase of the stride is reduced, the horse has to start to use the front legs to help with propulsion, making it heavy on its front end. This in turn can lead to back pain as there is a direct link from the pedal bone in the hind leg to the area under the saddle and if the horse does not have skeletal alignment, this back pain could well be coupled with a high head carriage and the consequent need to use all sorts of aids in order for the rider to bring the horse down on the bit.

What do we mean by skeletal alignment? When the horse is standing squarely, its weight should descend down through the middle of all the joints, including the pedal or last joint of the limb. If the pedal bone is levered back by the horse having a long toe behind, it pulls on its Deep Digital Flexor Tendon (DDFT), thus pulling down the horse's back under the saddle and giving back pain. The unfortunate person who then comes along to treat the horse for this pain may well be treating the symptoms rather than the cause of the problem itself.

Illustration showing direct link between the Pedal Bone & saddle region of the horse - reproduced by the kind permission of Dr Joyce Harmen

Illustration showing direct link between the Pedal Bone & saddle region of the horse - reproduced by the kind permission of Dr Joyce Harmen

So what are the effects of misalignment of the hind limb and how can we treat the problem and restore the horse to full power?

Before shoeing

Bradley is a four year old dressage horse and is already showing signs of a long toe, by having to stand under himself and the line of the coronary band hitting him above the knee

After Shoeing

Bradley is now displaying a rounder top line and a more relaxed stance

Firstly you must determine whether the pedal bone is out of line by standing back from your horse whilst it is standing at rest and observing whether the feet are long in the toe. Also, does your hose stand with its hind feet under itself and, if you take a line from the Coronary Band forward to the front leg, does this line hit the front leg above or below the knee? It should be on the knee or just below. Above immediately tells us that the pedal bone is in a negative position.

Travelling further up the horse's leg, have the hocks got less of a bend in them than usually associated with their breed?

Up to the back now - has your horse got muscle wastage and a poor top line with a slightly sunken back and a neck that is upside down i.e. with more muscle below than above? Well, some or all of these problems could be related to hind limb misalignment.

When you are riding, is your horse cold-backed when mounted, does it have a high head carriage and hollow back; is it riding on the forehand and has a short part to the power phase of the stride? These could possibly point to problems with the hind feet!

How to turn this around? We could use what we used to call 'hunter-style' shoeing. This is where the shoe is fitted across the foot, bringing the toe of the shoe under the foot and fitting it to the front edge of the pedal bone. This uses the shoe to reduce the leverage force on the pedal bone that is created by a long toe. When the foot is trimmed the heels should not be left high, but should be trimmed to the widest part of the frog as the frog has a vital part to play in the alignment of the bones of the lower limb. So, do not insist that the frog is trimmed as the bigger the frog the better the job it will do! The frog should push up into the foot when making contact with the ground not descend seeking the pressure it needs as this will cause the inner workings of the foot to descend with it, which will distort the toe forward.

At the toe, the rasp should just undercut the hoof at an angle of 25-30 degrees, just to round off the horn in front of the shoe, but does not remove the hoof wall as at the toe the wall is at its thickest, as is the sole.

This gives stability to the pedal bone as it is only the back part of the foot that can expand and contract. If we leave the structures that give stability to the pedal bone, place the shoe to remove the leverage affect of the long toe and get the frog to push up into the back part of the foot, the legs should come back to a position where the skeleton is in a position to bear the horse?s weight. This removes unnecessary pressure from the soft tissues, i.e. muscles, tendons and ligaments enabling the horse to rest without tension in its back and allowing the top line to round and the head to come down when moving. When lunging, you should notice that the power phase of the stride has increased.

Before natural balance remedial shoeing

Before shoeing

Bradley has a short part to the power phase of the stride resulting in restricted movement

After natural balance remedial shoeing

After Shoeing

Bradley now has a longer power phase resulting in increased stride length and impulsion

In some instances where the frog is small, a graduated pad with a frog insert and impression material maybe needed to create the necessary pressure on the frog in order to stimulate the frog back into life. In very severe cases this may become a permanent way to shoe the horse.

Make sure that you:

Don't fall into the 'if it's not broke, don't fix it' brigade, but really observe your horse's action and act early to prevent a problem

Use the back people for maintenance and not just when you have a problem

Try to be present when your farrier shoes your horse and discuss with them exactly how your horse has been going in order to give them as much information as possible to help fine tune your horse?s movement.

Remember, it is important to look at your horse as a 'whole' and not focus just on the problem area as you may well be treating the problem but not the cause!