The Skeletal System
The horse's body is made up of 216 bones. The forelegs carry as much as 60 percent of the weight of the horse. By understanding the skeletal system of the horse, you can better understand how the horse moves and how movement may be hindered or aided when riding. For instance, in the diagram, you can readily see a huge bone at the shoulder just above and in front of the ribs. It isn't difficult to imagine that a saddle that rests too far ahead on the horse will interfere with movement of the shoulder structure.
FIGURE 9.5: The Skeletal System of the Horse
The horse's spine is composed of eighteen thoracic and six lumbar vertebrae. (Many Arabians have only five lumbar vertebrae.) The eighteen thoracic vertebrae have eighteen pairs of ribs attached to them. The neck contains seven vertebrae, and the croup (rear end portion of the spine) includes five fused vertebrae. The highest part of the back near the base of the neck is called the withers. The height of the horse is always measured in hands (one hand = four inches) from the highest point of the withers to the ground.