The horse’s skeleton

Under every part of the horse you can name lies a bone or a joint. Knowing the skeleton means understanding why the withers are the high point of the back, why the knee is not a knee, and what your saddle sits on.

In the exam programme

Identify the main parts of the skeleton.Common module B

An adult horse’s skeleton has about 205 bones. It carries the body, protects the organs — the skull shelters the brain, the rib cage the heart and lungs — and gives the muscles levers to pull on, attached to them by tendons. The bones meet at joints, held together by ligaments.

7 cervical vertebrae: the neck
Shoulder blade (scapula)
18 thoracic vertebrae: withers and back
6 lumbar vertebrae: the loins
Pelvis
Sacrum: 5 fused vertebrae
15 to 18 coccygeal vertebrae: the tail
Femur
Patella: the stifle
Tibia
Calcaneus: the point of the hock
Tarsus: the hock
Hind cannon bone (third metatarsal)
Phalanges
18 pairs of ribs
Sternum
First, second and third phalanges
Proximal sesamoids
Cannon bone (third metacarpal)
Carpus: the knee
Radius and ulna (olecranon: the point of the elbow)
Humerus
Skull

Fig. 5.4The main parts of the skeleton

The spine

Region	Vertebrae	Where to find them
Cervical	7	The neck; the first two are called the atlas and the axis
Dorsal (or thoracic)	18	The withers and the back; each carries a pair of ribs
Lumbar	6, sometimes 5	The loins, behind the saddle
Sacral	5, fused	The sacrum, under the croup
Coccygeal	15 to 18	The tail

The withers are formed by the long spinous processes of the first dorsal vertebrae: this is the fixed point from which a horse’s height is measured. The 18 pairs of ribs and the sternum, or breastbone, form the chest; 8 pairs attach directly to the sternum, the other 10 do not.

The foreleg, from top to bottom

The scapula (shoulder blade) forms the shoulder; its joint with the humerus makes the point of the shoulder.
The humerus is the bone of the upper arm.
The radius, the bone of the forearm, is fused to the ulna, whose top, the olecranon, forms the point of the elbow.
The carpus, seven or eight small bones, is the horse’s “knee”: it corresponds to our wrist.
The large metacarpal is the cannon bone; two small metacarpals, the splint bones, lie alongside it.
At the fetlock, the two proximal sesamoids; then the first phalanx (long pastern bone), the second phalanx (short pastern bone) and the third phalanx (pedal bone, inside the hoof), with the distal sesamoid, or navicular bone, behind it.

Did you know?

The horse has no collarbone. Its forehand is not attached to the trunk by any bone: the chest hangs between the two shoulders in muscle and ligament, like a hammock.

The hind leg, from top to bottom

The hip bone, which makes up the pelvis, joins the ilium (point of the hip), the ischium (point of the buttock) and the pubis.
The femur is the thigh bone; the patella sits at the front of the stifle.
The tibia is the bone of the gaskin, or second thigh; the fibula, much reduced, is fused to it.
The tarsus — the hock — has six or seven small bones, including the talus and the calcaneus, which forms the point of the hock.
The large metatarsal (the hind cannon) and its splint bones, then the sesamoids and the phalanges, as in the foreleg.

Remember

The horse’s knee = the carpus, our wrist. The hock = the tarsus, our ankle. Below the knee and the hock, the horse walks on the equivalent of a single finger.

Ekidemy

The Galops^®, from the first step to Galop 7