Horses’ ability to outrun natural predators is crucial to their well-being and survival, so their limbs are extremely important. Equine patients must be accurately assessed and diagnosed when working with them. To accomplish this, horse leg anatomy must be well understood and applied.
Therefore, we must emphasize that limb health is important to an animal’s health; limbs can become overloaded, causing injuries while performing certain activities.
The horse has 2 limbs
We will separately discuss the anatomy of the forelimb and hind limb.
Horse Leg Anatomy: Forelimb
A horse’s forelimbs are not joined by joints but rather support the weight of a horse and a rider with tendons and muscles. As a result of these muscles and ligaments, the shoulder blade moves freely and absorbs concussions.
Located above the shoulder blade, the Humerus connects the forelimbs to the upper end of the shoulder. Upper leg bones are the ulna and the radius, which form the elbow and knee joints, respectively.
Foreleg movement is facilitated by the knee joint, which contains the carpal bones. Cannon bones are found between the knee and fetlock joints and bear weight. A splint supports the two carpus bones of the knee, each on either side of the cannon bone.
Behind the fetlock joint, there are two bones called sesamoids. These bones act as pulleys to move the lower leg by holding the tendons in their grooves.
A pastern bone is located above and below the pastern joint, with the long pastern located above the joint where the fetlock connects and the short pastern located below the joint where it connects to the coffin joint.
As attachment points for tendons and ligaments from the forearm muscles, the pedal bones are shaped like a horst in the foot. P3 is another term for pedal bones. This is the main bone of the forelimb of the horse.
Behind the pedal bones, there are small bones called navicular bones. As a pulley, it is attached to the pedal bone by a deep flexor tendon.
Horse Forelimb Muscle Anatomy
Anatomically, it is in the radial tuberosity of the scapula and originates from its caudal side. It prevents the elbow from bending and is part of the stay apparatus.
On the proximal side of the humerus, it inserts on the craniomedial side of the proximal radius. It serves as a flexor.
It attaches to the distal side of the caudal humerus on the lateral side of the olecranon. Whenever the joint is extended, excess pressure is prevented on the joint due to the joint capsule being raised.
Tensor fasciae antebrachii:
Initially, it is attached to the dorsal front of the scapula, then pulls caudally to the latissimus dorsi before inserting into the olecranon. A small amount of extension is obtained from this muscle.
Three heads arise from the scapula and insert into the olecranon at different locations: one on the caudal side of the scapula, one that inserts into the humerus on the caudal, medial, and cranial sides of the humerus, one on the caudal side of the humerus. An elbow’s most important extender is the triceps brachii. This muscle is crucial to keeping the elbow in place.
Extensor carpi radialis:
It inserts on the surface of the metacarpal tuberosity after it emerges from the humerus. It extends the wrist and flexes the elbow. This is also what holds the carpus in position when the stay is used.
Common digital extensor:
Located at the bottom third of the radius, its distal part originates from the humerus and travels distally. The lateral tuberosity of the radius provides one end, while the tendon provides the other end. Extends the tendons that attach to the wrist, pasterns, and coffins. It also flexes the elbow.
Lateral digital extensor:
Located on the proximal surface of the metacarpal, it arises from the lateral tuberosity of the radius and the ulna.
Extensor carpi obliquus:
It lies on top of the second metacarpal as it rises from the radius. This increases the diameter of the carpus.
Flexor carpi radialis:
The proximal end is attached to the humerus, and the distal end is attached to the second metacarpal. This allows the elbow to be flexed and extended.
Horse Hind Limb Anatomy
Anatomy of the rear leg of a horse includes the pelvis, the femur, tibia, fibula, metatarsus, and phalanxes. Additionally, it includes the hips, stifles, hocks, fetlocks, pasterns, and coffins.
Three bones, the ileum, ischium, and pubis, make up the upper part of the hind limbs. The ischium is the point at which the buttock begins. Through the sacroiliac joints, they are connected to the spine, and they act as a means of propelling the hind legs.
In the pelvis, the uterus and other internal organs are protected. Located at the hip joint and the stifle joint, the femur is a large bone that connects to the pelvis.
From the stifle to the hock, the tibia makes up the upper portion of the hind limb. Fibula, a shorter bone, is parallel to the tibia and stretches half of its length.
The kneecaps are located above the fibular and tibial bones of the stifle joint. At the back of the hind leg, the point of the hock is in the hock joint. The hock joint is composed of the tarsus, the tuber, and the calcaneus.
The hind limb has several joints and bones, including the cannon, leading, and trailing pastern, and the sesamoids and navicular near the pedal. They are the same as discussed in the forelimb.
Horse Hind Limb Muscle Anatomy
It originates from the gluteal fascia and is attached to the femur through the tuber coxae. Supports hip abduction and flexion.
This muscle originates from the ilium and longissimus dorsi aponeurosis, as well as the dorsal, lateral, and sacroiliac ligaments. Allows abduction and extension of the hip.
Located along the shaft of the ilium and inferior ischiatic spine, it is attached to the femur. Facilitates inward rotation of the limb.
Down to the pubic tendon, it originates from the pelvic symphysis. Induces adduction of the limb.
Originates from the first 4-5 lumbar vertebrae and the last three thoracic vertebrae, inserted into the ilium. It is responsible for flexing the pelvis.
With a tendon that passes through a tendon of the iliacus, it inserts into the trochanter minor of the femur from the lumbar vertebrae and the last two ribs. Provides hip flexion and femur abduction.
Anatomically, it is located on the caudal side of the femur, which is located on the ventral side of the ischium. Adducts the thigh and extends the hip.
This muscle arises from the sacrum’s wing and attaches to the side of the two last ribs. Provides lateral movement to the horse.
Located in the medial patellar ligament and tuberosity of the tibia, the muscle arises from the iliac fascia and the psoas minor tendon. Flexing the hip and adducting the limb are its functions.
On the ventral side of the tuber ischii and caudal side of the Sacro sciatic ligament, this muscle makes up the dominant muscle of the leg. Joints of the hip joint are extended; the limb is adducted.
A tendon is a band of dense connective tissue that attaches muscles to bones or cartilage. Actively transferring load across joints or providing some movement is the purpose of these structures.
Digital flexor tendons have evolved in horses as a means of storing energy, absorbing shock, and supporting the horse’s weight-bearing joints.
A ligament binds together the surfaces of two bones or cartilages. The suspension ligaments (SL) are attached to both the fore and hind cannons.
The SL’s primary objective is to prevent the fetlock joint from becoming overextended. The strength of the SL can be increased by training racehorses.
Deep digital flexor tendon
There are three possible locations for DDFTs in the forelimb: the humerus, radium, and ulna. This joint runs down the carpal canal and crosses over the navicular to insert at the back of the coffin bone. It lies just over the suspensory ligament and deep beneath the SDFT.
Moreover, it inserts two sections of the tibia on the hind limb, as well as the head of the coffin bone. It functions in flexion and extension of the knee and forefoot, forelimb elbow joint extension, and flexion and extension of the hock and hindfoot.
Frequently Asked Questions
What is the name of the horse’s knees?
The carpus (carpal joint) is known as the knee, only on the front legs. The tarsus, commonly called the “hock”, corresponds to the hock joint on the hind leg.
Why do horses stand on three legs?
Horses standing on three legs are usually very relaxed, and the leg not bearing any weight is resting. Take a moment to observe the horse, and you will see that its “other” hindfoot is resting. It may also be that they are sleeping.
Is a horse leg a finger?
The bones under the knee of a horse are like those in a human hand and middle finger, so yes, they are similar.
So, if you want to understand horse leg anatomy properly, you must give a read to this article. It is crucial to keep this in mind when managing, to train, or treating your horse.
The language has been simplified so that even a non-professional can easily understand it. We hope that this article will answer all your questions regarding Horse leg anatomy.
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