The horse’s body is a remarkable design. Its limbs are long and straight, making it possible for them to be used to make powerful strides that propel the animal forward at speed. The skeleton of the forelimbs consists of the humerus, radius and ulna, as well as the carpal bones, metacarpal bones and phalanges. The hind limbs are also long and straight, with the tibia and fibula supporting the femur. In addition, the carpus is fused with the ulna, so that the ankle joint has no moving parts. The phalanges have two sesamoid bones called the proximal and distal.
The gastrointestinal tract is one of the horse’s most important organs, as it allows the animal to digest both forage and concentrates. In fact, horses have a very unique digestive system with different structures on the left and right sides of the abdomen. This made it necessary to paint a number of paintings to show the anatomy of the stomach, duodenum, pylorus and other structures on each side. This information is useful in feeding a horse properly, and it is something Gillian looks at in detail in the on-demand seminar Digestive Anatomy, Feeding and Nutrition and her book Horse Anatomy for Performance.
Another very important part of the horse’s anatomy is the urinary system, which not only excretes urine, but also regulates hydration. This is extremely important because muscles and fascia need to be hydrated in order to work effectively. Gillian also talks about the hydration and how it affects muscle performance in her on-demand seminar Hydration for Performance.
Lastly, there are the internal structures that make up the nervous system. The brain and spinal cord are protected by a bony structure called the skull and the vertebrae respectively. The brain integrates all the signals from the rest of the body and coordinates their execution. The spinal cord transmits impulses from the brain to all other parts of the body via nerve cells, called neurons.
In the equine body, the main muscle groups are the quadriceps femoris, adductor iliotibial band and the gastrocnemius. The quadriceps femoris is a group of muscles located on the front of the thigh, which are responsible for pushing off with the leg when a horse is running. The gastrocnemius is the largest muscle of the leg and it helps to extend it.
Other major muscular groups are the pectoralis muscles and the latissimus dorsi. The latissimus dorsi is involved in pulling the legs backwards.