“There are many wonderful places in the world, but one of my favorite places is on the back of my horse.” A famous saying by Rolf Kopfle. A horse health well-being is often judged by its ability to run, and healthy limbs are extremely important for this. Basically, the horse legs are developed to support heavyweight and run long distances.
Here we will discuss the anatomy of the horse leg and see how different bones, joints, ligaments, and tendons come together to form a healthy horse.
Forelimb of Horse
Firstly horse forelimb or front legs consist of following bones such as:
- Scapula
- Humerus
- Radius
- Ulna
- Carpus or Knee (comprise of 7 or 8 carpal bones)
- Large metacarpal bone (Cannon bone)
- Medial and small metacarpals ( also known as Two splint bones)
- First phalanx (Long pastern)
- Second phalanx (Short pastern)
- Third phalanx (Pedal bone)
- Two proximal sesamoid bones
- Distal sesamoid bone (Navicular bone)
Meaning of Scapula
It is the first bone of the forelimb. It is a flat, triangular bone, and it slides over the rib cage. The scapula is generally present at a 45 ° angle. The length of the horse’s stride and the horse’s shoulder slope are determined by the length and angle of the scapula.
The thorax region is hung between the two scapulae with the help of tendons, muscles, and ligaments. Overall, this organization is known as a thoracic sling.
Humerus Bone
The humerus and scapula form the shoulder, and the ball and socket joint is present in the humerus and scapula.
The humerus is a very strong bone and is present at an angle that acts as a shock absorber.
The shoulder can do different movements like flexion, extension, rotation, adduction, and abduction.
The ball and socket joint provides the greatest movement of all joints.
Radius and Ulna of the Horse legs
The Ulna and Radius of the horse are the same as that of the lower human arm, but there is a unique difference that the horse’s ulna and radius are fuses to prevent twisting of the horse’s foreleg.
Except for the olecranon process, the ulna is very small because it forms the elbow. The ginglymus joint, also known as the elbow joint, forms between the radius, humerus, and ulna and only moves in a single direction.
Knee (Carpus)
The horse’s carpus or knee is just like the human wrist. Similarly, it is composed of seven or eight small metacarpal bones organized in rows, one on top of the other.
- The upper row consists of intermediate, radial and ulna carpals along with pisiform bone or accessory carpals. It does not stand weight at the back.
- The bottom row is made up of all the four carpals.
This joint is also a shock absorber. It also allows movement in only one direction, such as flexion and extension.
So when the knee is stretched, the hoof travels towards the elbow and shows no twisting or lateral motion.
Hind Limb of the Horse
Meanwhile hind limbs of the horse consist of following bones:
- Pelvic girdle
- Femur
- Tibia
- Tarsal bones
- Cannon and splint bones (Three metacarpals)
- First phalanx (Long pastern)
- Second phalanx (Short pastern)
- Third phalanx (Pedal bone)
- Sesamoid bones (two)
- Navicular bone
Pelvic Girdle
If we talk about the pelvic girdle, it is formed by the fusion of two hip bones, the first three coccygeal vertebrae, and the fused sacral vertebrae. Each hip bone consists of three components, ilium, ischium, and pubis, and they fuse together.
Ilium, ischium, and pubis, all of these bones are located in the acetabulum, and the femur attaches with the hip bone to form the hip joint.
Structure of Ilium Bone
It is one of the largest bones that make up the complete os-coxae. It has two angles, the angle that makes the tuber coxae or the tip of the hips known as the outermost angle and the angle that, with the help of two ilias together, make the uppermost point behind the loin known as the tuber sacrale or internal angle.
The sacrum is joined with ilium at the sacroiliac joint, the fibrocartilaginous joint, and a combined synovial. These are supported by the lateral, dorsal and ventral sacroiliac ligaments.
Horse’s Ischium
Basically ischium forms the back end of the pelvis and the tuber ischia is one of its thickened ends and they form the tip of the horse buttock.
Pubis
The pubic bone has a pubic groove and forms the front of the pelvis floor. Both the left and right pubis is located in the pelvic symphysis, which fossilizes with the time.
Femur of Horse legs
Like the humerus, the femur is a large bone and is present in the middle of the stifle joint and the hip joint. The muscles of the hindquarters are attached to the bone of the femur.
Tibia
The horse’s tibia is a long bone and is present between the stifle joint and the hock joint. The upper end of the tibia provides the place for the junction of the muscles in the hock and the lower limb. The horse’s fibula bone is so small that it is almost vestigial.
Tarsal bones
The tarsus also known as hock is made up of six or seven flat, short, and dorsal bones. These bones are organized in three rows. The first row contains the calcaneus and the talus. In the central row, the central tarsal is present, and the third row contains the first and second fused tarsal and the third tarsal. While the last tarsal occupies the lower and middle row.
Patella
It is basically a small bone plate, also known as the knee cap, and protects the knee joint in humans. The knee joint form where the tibia and femur meet, and in horses, this joint is known as stifling joint.
Point of Hock
The hock joint in the horse is present in the hind limb, just above the cannon bones. It is the same as the human ankle.
The horse’s hock joint has a significant place in the horse’s anatomy because it withstands the high tension when the horse runs.
After the hock joint, the structural arrangement of the hind limb is the same as that of the forelimb.
How Do Horse Legs Function?
In summary, horse legs are made up of various apparatuses consisting of muscles, tendons, ligaments, and connective tissue. All of these devices work together to help stand, move, and protect from injuries to the horse legs.
Unfortunately, often horses face health problems like tendon or ligament injuries. Although there is a bunch of different treatment options part of them costs a lot of money and takes a lot of time. However, with the right treatment choice and combination, you can save a horse, time, and money.
