Conformation is what we refer to when we're speaking of the relationship between the structure and function of a horse. Ideally, the hors's conformation looks good and works efficiently for whatever job the horse has. In the wild, a horse must be able to move around easily in its environment, to find food and water and also to escape quickly from danger if necessary. We, as the horses' owners, can protect our domesticated horses with boots and bandages, but the horse is most likely to perform well if it has good conformation.

A horse should have good "clean" symmetrical limbs that can gallop at top speed without worrying about jarring the joints. A nice deep, wide chest is necessary to contain the heart and lungs, and propulsion comes from powerful, well-built hindquarters. The horse's head should be in proportion to the rest of the body, and the neck should be set well on sloping shoulders. Most of the horse's body weight is between the front and back legs. The hors's spine must be very rigid to support this weight. This is why it's important to not ride a horse much before it reaches maturity at 5 or 6 years old. The horse's head acts as a balance on the end of the neck during movement.

Although the leg joints of most horses are pretty much the same, they have adapted to the role that the particular breed has to fulfill over the centuries. Speed comes better to thin, lighter legs, and large joints spread the weight of a heavy horse over a greater surface area. Small joints on a large horse, or vice versa, could cause problems. Although it is difficult to find a horse with legs that are perfect, the better they are, the less likely they are to have problems. The horse she be able to stand square, with the hind legs exactly behind the forelegs. Each pair of legs should match - the joints should be the same size, the legs should be vertical. Looking at them from the side, the legs should be straight, apart from the hock angle. The feet should be straight, not turned in or out, and there should be no apparent swelling or puffiness in the joints or tendons.

Conformational defects keep the horse's weight from being supported evenly throughout the whole leg. Extra stress gets put on certain area, causing problems later on down the road. If a horse is over or back at the knee, its weight is shifted onto the heel region of the foot. Toes turned in or out put unequal strain on one side of the fetlock or foot. If the hocks are too far under the horse, the muscles have to make the maximum effort too early in the stride. If they are too far behind the horse, the effort comes too late to achieve proper impulsion. Cow hocks and bowed hocks weaken the propulsive force of the legs because the legs tend to be more bent than straight.