Few animals can compare with a horse when it comes to performance. A huge body, large weight, thin legs, small feet – how is it possible for horses to perform as well as they do? Or could it be that these thin legs and small feet are actually part of the success story?

And what about the tendons, those structures that cause us as riders and owners so much concern, and often are the reason for breakdown? Why can't the muscles be closer to the feet, with less tendon to worry about?

The secret of the horse's success as an athlete, lies in the efficiency with which it moves its legs. When one analyses this movement a fascinating story unfolds, leaving one once again in awe of the creation and its Creator!

Going forward
Stop to think for a moment. A horse galloping at speed probably does in the region of 65 km per hour. But how fast must his feet move to keep him going forward? He has to pick up his feet, move them forward and put them down again to allow for continuous forward movement. Easy enough, is it not?

No, that is not the full story! He does not only pick his feet up – he actually uses muscle power to push them off the ground, to give him more lift, and with that, more speed. And he has to move his feet faster than his body to make sure that they end up in front, otherwise he will not move forward.

To add to the complexity of all this, he has to reduce the speed with which he moves his feet forward before he puts them down to reduce the impact when they make contact with the ground. At the middle of the swing phase, the feet are moving at slightly more than twice the speed at which the horse travels.

So, to answer the question – if a horse is galloping at 65 km per hour, his feet will reach speeds of close to 150 km per hour at the middle of the swing phase!

How can this be achieved? Mostly by the unique design of the horse's body. Let's have a closer look.

Unique design
First, there is the unique design of a single toe, and the fact that the horse actually walks on the tip of it. A long, slender leg, with little weight at the bottom end (the cannon, pastern and foot make up less than 1% of the horse's body weight). No heavy muscles close to the foot, but rather long tendons, which weigh little.

All the musculature that makes the leg move, is placed high up, putting the weight close to the pivot point (in this case, the joint) around which the leg swings forward. Why is this important?

To be able to move his legs forward, the horse first must overcome the resistance of the leg to move at all. This resistance is the result of a combination of the weight of the leg that is to be moved and the distribution of this weight relative to the joint around which the leg rotates. If more weight is situated at the point furthest from the joint, more energy is required to move the leg forward.

With the heavy muscles situated close to the joints around which the legs swing (the hip for the hind legs, and the elbow for the front legs), the horse is an excellent example of almost perfect design!

A warning, though – and keep this in mind at all times: Even the smallest addition of weight to the lower limb will mean that the horse uses more energy to move his legs forward. Use lightweight shoes, and do not use heavy tendon or brushing boots if they are not absolutely essential.

Muscle power
The horse does not merely lift his feet from the ground when moving forward. He uses muscle power to push his feet harder against the ground to achieve more thrust. This is especially important in the hind legs, which drive the horse forward when he is moving at speed.

The more push, the more thrust, and the more speed. This is obvious when one looks at race horses, which all have heavily muscled hindquarters. But it is equally important in endurance horses which, although not moving at the same speed, still move forward by using the same principles.

But there is more! The tendons are not only light, much lighter than muscle, but some of them also are elastic in nature. The superficial flexor tendon at the back of the leg is a perfect example of this.

Elasticity
Elasticity is the ability to recoil after having been pushed or stretched out of shape. When the foot hits the ground, taking load, the flexor tendon stretches as the fetlock is extended. This stretching stores mechanical energy in the tendon. When the weight is taken off the foot, the energy is released and the tendon recoils back into its original shape.

This recoiling of the tendon makes the joints of the leg bend, and the horse does not have to use muscle power to do so, thereby saving energy and improving the efficiency of motion. At higher speeds, more load is placed on the legs, the tendon stores more energy, providing more recoil and causing the legs to bend more and lift higher from the ground.

Built to move
Designed for efficient movement, the horse really is a super athlete. They have been given to us to enjoy, to ride, to compete on and to reach our goals. In return we only have to love them and care for them – be a responsible horse owner!