Horse Leg Anatomy Guide and How to Treat Injuries 

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Tanya Taylor

Tanya is a professional horsewoman who has worked with horses for over 25 years. She spent 5-years birthing down some of the world's finest racehorses in Newmarket, the home of horse racing, and currently lives in Spain, where she enjoys hacking in the hills.

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I love equine anatomy and studied it as a student at The National Stud in Newmarket, UK. For those who don’t know, Newmarket is the home of horseracing, and if there’s one thing a racehorse needs – it’s good legs.

Leg problems are bad news for a thoroughbred, or any horse, for that matter, and for the best chance of dealing with them, you need to understand how the horse’s legs work. If you’re curious about your horse’s legs, take a look at my horse leg anatomy guide below.      

In this guide, you can learn:

• Horse leg anatomy
• Common leg problems in horses
• Basic first aid for leg problems

Bottom Line Up Front

A horse has four legs, two forelegs, and two hind ones, and they are split into two categories – the upper and lower leg. Horses use their legs to move and communicate, and their strong legs keep them safe from predators in the wild. 

Horses’ legs are complex structures made from bones, tendons, muscles, and ligaments that hold the horse’s weight and absorb the shock from their powerful movements. The fore and hind lower legs are anatomically the same and consist of the cannon bone, splint fetlock, sesamoids, patterns, and coffin bone.

Horses Legs – A Quick Overview

Their legs are one of the most defining things about a horse – if it wasn’t for their powerful legs, strength, and stamina, we wouldn’t have formed such a devoted partnership with them. A horse’s legs make them exceptional athletes and faithful, reliable workers.

The front legs of a horse are called the forelegs, and the back legs are called the hinds. Most of a horse’s weight is on its forelegs, and they use their hind legs for propulsion. Horses use their legs to move around, so their legs are strong enough to carry their hefty weight and act as shock absorbers when they are in motion. 

When a horse is resting, the back legs can lock into place – which is why they can sleep on one leg. Horses also communicate with their legs, pawing the ground when they are impatient or lifting their back legs as a threat – they also kick at their abdomen if they have stomach pain. 

What Are The Different Parts of A Horse’s Leg? 

The horse’s legs are categorized into two parts, the upper and lower. The upper consists of bones, tendons, muscles, and ligaments, but the lower leg doesn’t have any muscles. The upper legs on the fore and hind are different, but the lower legs share the same anatomy.

To be a knowledgeable equestrian and competent owner, you must understand horse leg anatomy. So, to help you get a better understanding of equine legs, I’ll guide you through the different parts below.

Horse Leg Anatomy – Upper Hind Legs

A horse’s upper hind legs start at the hip and end at the hock, with the femur, stifle, fibular, and tibia in between. A horse uses hind legs for propulsion rather than weight bearing, so they’re generally less susceptible to injury.

Let’s take a closer look at the parts of the upper hind legs:

#1 – The pelvis

The hind legs start at the pelvis, which is connected to the spine and contains the hip joint. The hip joint consists of three bones, the ilium, pubis, and ischium, and it connects the femur to the pelvis. The pelvis supports the hips, and mares have a wider pelvis than geldings or stallions so they can carry a foal. 

#2 – The Femur

The femur is the longest bone in a horse’s body – it attaches to the hip with a large ball and socket joint and runs down to the stifle, where it joins with the tibia and patella. The femur is a strong bone responsible for power and movement, and it’s a crucial attachment point for many muscles and ligaments of the leg.

#3 – The Stifle

The stifle is the largest joint in a horse’s body and is similar to a human knee – it’s a hinge joint that moves the leg back and forward. The stifle joins the femur and the tibia and contains a patella (knee cap). The kneecap moves up and down and locks the stifle joint allowing horses to rest and sleep on one leg. The stifle is a complex area which contains two joints.   

#4 – The Fibula and Tibia

The Fibula and tibia are two bones that run from the stifle to the hock and bear the most weight from the hind legs. As well as bearing weight, these bones are also an attachment area for the major muscles in the hind legs. The tibia is longer than the fibula, and the bones are fused. 

#5 – The Hock

The hock, also known as the tarsus, joins the upper leg and lower leg together – it attaches the tibia to the cannon bone (a horse’s shin). The hock is a complex area – it consists of 4 different joints and gives your horse the power to spring over fences. 

Horse Leg Anatomy – Upper Forelegs

The upper forelegs consist of the shoulder, humorous, elbow, radius, ulnar, and knee. Horses usually have more problems with lameness on their forelegs because they carry most of the weight.

Let’s take a closer look at the parts of the upper forelegs:

#1 – Scapular

The front legs begin at the Scapular or shoulder blade, a large flat bone that makes up part of the withers. The Scapular is attached to the humerus at the point of the shoulder and is one of the main reference points when you assess a horse’s conformation. 

#2 – The Humerus

The humerus is a long bone and is one of the strongest in the horse’s body. It must be strong because it functions as a shock absorber, but it’s also a critical attachment point for many muscles of the upper foreleg. The humerus attaches a horse scapula to the elbow. 

#3 – The Elbow

The elbow is a hinged, synovial joint which connects the humerus with the ulna and radius. The elbow helps the horse to flex and extend its foreleg. 

#4 – The Radius and Ulna

The radius and ulna are the equivalents of a human forearm, and they join the elbow to the knee. The radius bears most of the weight of the forelegs, and the bones are fused in adult horses. 

#5 – The Knee

A horse’s knee is also known as the carpus. It’s a complex joint that consists of 9 small bones in 2 rows that make three joints and are held together by a tight ligament network. The knee connects the parts of the upper foreleg to the cannon bone in the lower leg, and it helps your horse with stability. 

Horse Leg Anatomy – Lower Legs

The parts of a horse’s lower leg are the same on the fore and hind legs and include the cannon bone, splint, fetlock, sesamoids, and coffin bone. Some bones in the hind legs are larger than those in the forelegs, but they all serve the same purpose. 

Below, I’ll tell you about the different parts of the lower legs:

#1 – The Cannon Bone

The cannon bone is also known as the large metacarpal – in humans, we call it the shin bone. The cannon bone is long, hard, and oval-shaped, and it connects the lower legs from the hock in the hind legs, or knee in the forelegs, to the fetlock. 

#2 – The Splint

The splint is also known as the small metacarpal, and there are two splint bones on either side of the back of the cannon bone. Splint bones are long and thin – they support the horse knee and protect soft tissue such as tendons, ligaments, nerves, and blood vessels. 

#3 – The Sesamoid bones

The sesamoid bones are small pyramid-shaped bones that sit behind the fetlock joint, next to the cannon bone, and are attached by ligaments to the pastern. Sesamoid bones strengthen the fetlock and provide leverage to the ligaments and tendons of the lower leg – they also act as a rest for the flexor tendon. 

Horses have three sesamoid bones in each leg, the proximal sesamoids, and a distal sesamoid, also known as the navicular. Sesamoid bones are small and delicate and are vulnerable to injuries, especially in racehorses and sports horses with long pasterns. 

#4 – The Fetlock

The fetlock joint is where the cannon bone joins the pasterns and is the equivalent of a human ankle. The fetlock is a hinge joint that moves the pasterns and hoof forward and backwards but not from side to side.

The fetlock is a complicated and highly mobile joint consisting of the sesamoid bones and a complex network of tendons and ligaments. It absorbs most of the impact from a horse’s legs and can sprain easily. 

#5 – The Pasterns

From the outside, the pastern looks like one bone, but the horse has two patterns in each leg, a long and short one. The long pastern is mostly immobile, and the short pastern allows the foot to be more flexible. 

The pasterns sit between the fetlock and the coffin bone and help with mobility and directly affect a horse’s stride and gait. The pasterns are shock absorbers and help horses find balance on uneven ground, and long pasterns are a desirable trait in sports and racehorses.

#6 – The Coffin Bone

The coffin bone is the last in the horse’s legs and is also known as the pedal bone or the distal or third phalanx. It sits firmly in the hoof, and acts as a shock absorber, and is an attachment point for the tendons of the lower leg. The coffin bone is a shovel-shaped, porous, delicate bone attached to the blood vessels and nerves in the hoof.

Tendons of The Lower Leg

Horses don’t have muscles in the lower leg – it’s made up entirely of bone, tendons, and ligaments. Tendons and ligaments are tight, fibrous straps of connective tissue made mostly of collagen. They hold the leg structure tightly in place and allow for controlled, stable movement of the limbs.

Tendons attach muscle to bone and are more stretchy than ligaments which attach bone to bone. Tendons and ligaments are elasticated, but under an intense workload, a horse can overstretch them, which results in lameness and injury. 

Here are the most important tendons in a horse’s legs:

1. Common Digital Extensor 
2. Lateral Digital Extensor 
3. Deep Digital Flexor Tendon 
4. Superficial Digital Flexor Tendon 

Common Horse Leg Problems

Horses are tough animals, but when they have problems, it’s usually in their legs. Horse’s legs are complex appendages – they work hard, and many things can go wrong with them. Leg problems in horses can be mild or severe – in severe cases, they can reduce a horse’s life span, permanently put them out of work, and even lead to death. 

Your horse has a better chance of recovering from leg problems if you catch them in the early stages. So, to help you recognize the most common health issues associated with your horse’s legs – I’ve listed a few below. 

Problem #1 – Lameness

Most leg problems result in lameness. A horse’s legs are very complex, they can go lame at any point in the leg, and lameness is sometimes hard to diagnose. Lameness is caused by multiple things, from an injury during exercise to infection or chronic conditions such as poor conformation or laminitis. 

Signs of lameness in horses include:

1. Reluctance to walk or put weight on the leg
2. Resting the leg a lot when standing
3. Lying down a lot
4. Uneven gait
5. Nodding head up and down when walking 
6. Dragging their toe
7. A change in behavior

Most lameness comes from the foot, and it’s more common for horses to have problems in their lower leg than the upper leg. Many things can make a horse lame, and below, I’ve listed the most common reasons for horse lameness.

Abscess

Horses can get these anywhere, but they’re most common in the hoof. An abscess is usually the result of a puncture wound that has become infected. The pressure of the abscess builds up behind the hoof wall as it’s painful for horses to walk on. In most cases, abscesses are easy to treat, and horses usually make a full recovery.

Laminitis

Laminitis is a painful foot condition and it affects the coffin or pedal bone in horses. It occurs when horses have too much protein and sugar in their diet, and the telltale sign of laminitis is that the horses with the condition walk on their heels.

If left untreated, laminitis can make the pedal bone rotate, and the animal may have to be put to sleep. A horse can recover from laminitis, but usually, they’re prone to it afterwards. To manage it, you must be very careful with your diet.

A Tendon, Ligament, or Joint Injury or Sprain

Injuries and sprains usually happen in the main joints where many bones and tendons meet, such as the fetlock, knee, and hock – the main symptom is usually swelling. Depending on the severity, horses can recover from a tendon or joint sprain or injury with veterinary care and box rest – but, in severe cases, the area might be permanently damaged. 

Degenerative Diseases

Common degenerative conditions of the horse’s legs include arthritis, osteoarthritis, and bursitis. Horses usually won’t recover from degenerative conditions – they worsen over time. You can manage their condition under veterinary supervision and with a reduced workload, but degenerative diseases of the leg usually result in early retirement. 

Poor Nutrition

Horses need a balanced diet to thrive, and too little or too much of certain minerals can affect their development and lead to hoof cracks and degeneration.

Problem #2 – Poor Conformation

Horse conformation is about the angle and position of their joints and bones. A horse’s limbs and build should be aligned and symmetrical so you can draw an invisible straight line through points, like the shoulder, knee, and toe. 

A horse must have the correct conformation to be healthy and balanced. If they have poor conformation, it puts excessive strain on their body and can lead to health problems and chronic lameness.

Horses are usually born with conformation faults, and box rest is enough to “straighten” some foals out, but some horses will, unfortunately, be affected for life. You can manage some conformation faults such as toeing in or out with remedial shoeing. 

The most common horse leg conformation problems are:

1. Buck’s knees
2. Knocked knees
3. Bow legged
4. Bucked Shins 
5. Over straight hind leg
6. Splints
7. Long pastern
8. Short pastern
9. Toeing in
10. Toeing out  

Problem #3 – A Broken Leg

Broken legs aren’t that common, I’ve only seen two in my 20-year career of working with horses, but when they occur, it’s devastating news for a horse and its owner. Most of the time, if a horse breaks its leg, it has to be put to sleep. Horses can recover from some breaks, but it’s a long road to recovery, and for most of them, it means the end of their riding career.  

Horses with a broken leg are confined to a stall for months, so they’re immobile, which is terrible for a horse’s physical and mental health. The chances of recovery from a broken leg depend on the horse’s condition when they break it and the severity of the break.  

How to Help a Lame Horse

If I notice one of my horses is lame, the first thing I judge is how severe it is. If the horse can’t put any weight on the leg – I call the vet immediately. I’m a qualified and experienced horse person, and I’ll confidently give a horse first aid, but if you don’t have much experience, and your horse is in pain, call your vet or ask for help from a more experienced owner at your barn.

Usually, it’s obvious which leg a horse is lame on, but if I’m unsure, I ask someone to walk the horse on a firm flat surface – if it’s not too painful. When I identify the leg, I look for injuries such as lacerations or puncture wounds. 

If there are no injuries, I check the hoof for heat, trauma, or the distinctive smell of an abscess. If I don’t find anything in the foot, I look over the legs, particularly around the joints, and I run my hands gently up and down them feeling for heat and swelling, which indicate a strain or injury. 

When I pinpoint the cause of lameness, here’s how I treat it:

• For abscesses – I clean the foot thoroughly, apply a poultice dressing and change it every day or two. If the horse does not improve after 5-days, I usually call out the vet or blacksmith to treat the horse. 
• For injuries or lacerations – If the wound is small and superficial, I clean it with wound cleaner and hose the area with water for 10 minutes to cool it down. If the wound is deep, I call the vet out to dress it and give the horse antibiotics. 
• For Swelling and Sprains – I use cold therapy to help horses with swellings and sprains – this is when you hose the swollen area with cold water for 20 minutes at regular intervals. You can also submerge your horse’s legs in iced water or use special cold therapy boots. 

Always keep horses with injuries rested and call your vet if they are severely lame, in pain, or injured.

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