where is the cannon bone located on a horse
Limbs of the horse The anatomy of the forelegs begin at the scapula. This is the shoulder in which provides the ease of movement as it is connected to various bones surrounding it such as the cervical vertebra (a section of the spine). The next bone is the humerus which leads onto the radius below. The radius is then connected to the bones of the knee. The carpus is located at front of the knee and the pisiform is the back of the knee. Below the knee is the cannon bone which is also known as the 3rd metacarpal. 55 million years ago when the Eohippus existed, the cannon bone used to be the 3rd toe of the foot. It's fusion took place in order to increase height and power of the limb. Behind the cannon bone are the splint bones. The splint bones are also known as the 2nd and 4th metacarpal and fused 25 - 35 million years ago during the time of the Miohippus. They provide extra strength and support of the cannon bone and used to be the 2nd and 4th toes of the foot. Below the cannon bone is the fetlock joint in which lays a structure if many bones. Firstly are the sesamoid bones that act as part of the system that allows the leg to drop as pressure is applied and spring back up as pressure is released. Below this is the proximal phalanx also known as the long pastern which is followed by the middle phalanx (short pastern). Below these bones are the navicular bone and the distal phalanx. the distal phalanx can be known as the coffin bone or the pedal bone. Below the navicular bone is the navicular bursa. There are three main muscle groups of the forelimb. The triceps muscle straightens the elbow and foreleg, running from the elbow to the bottom of the shoulder blade. The muscles which extend the lower leg are called extensor muscles, while the flexion of the lower leg joints is achieved through movement of the flexor muscles. There are five main muscles and muscle groups in the hind legs. The vastus muscle flexes the hind leg and runs from stifle to hip, while the gluteal muscles, the large muscles in the hip, extend the femur. Forward motion and flexion of the hind legs is achieved through the movement of the quadriceps group of muscles on the front of the femur, while the muscles at the back of the hindquarters, called the hamstring group, provide forward motion of the body and rearward extension of the hind limbs. Extension of the hock is achieved by the Achilles tendon, located above the hock.[10]