Tendons and Ligaments of the Horse's Front and Hind Limb
Learn the eight tendons and ligaments that hold up and move a horse's lower leg. Tap any label to see where it runs and what it does, then test yourself on the blank diagram.
- Explore Tap any label to see where it runs, what it does and how it gets hurt.
- Label it Put all 13 names on the blank lines, then check your answers.
- Find it Locate 10 structures on the diagram from their name alone.
Label the tendons and ligaments of the horse's leg
Both legs face left, seen from the outside: the front of each leg is on the left and the back is on the right.
- Front limb: Radial Check Ligament
- Front limb: Main Extensor Tendon
- Front limb: Superficial Flexor Tendon
- Front limb: Lateral Extensor Tendon
- Front limb: Subcarpal Check Ligament
- Front limb: Deep Digital Flexor Tendon
- Front limb: Suspensory Ligament
- Hind limb: Lateral Extensor Tendon
- Hind limb: Subtarsal Check Ligament
- Hind limb: Deep Digital Flexor Tendon
- Hind limb: Main Extensor Tendon
- Hind limb: Suspensory Ligament
- Hind limb: Superficial Flexor Tendon
Main Extensor Tendon
Common digital extensor tendon (front), long digital extensor tendon (hind). Down the front of the cannon, from its muscle above the knee or hock to the top of the coffin bone (P3). Straightens the fetlock, pastern and coffin joints so the toe comes forward as the leg swings.
Front: Its muscle starts on the outside of the elbow. It also helps straighten the knee. Hind: Its muscle starts at the stifle. It also helps flex the hock, and the lateral extensor merges into it in the upper cannon.
Lateral Extensor Tendon
Lateral digital extensor tendon. Down the outside of the leg, just behind the main extensor. Helps the main extensor straighten the lower leg.
Front: Ends on the top front of the long pastern bone (P1). Hind: Never reaches the pastern. It merges into the main extensor tendon in the upper cannon, so below that point the hind leg has one combined extensor.
Superficial Flexor Tendon
Superficial digital flexor tendon (SDFT). Down the back of the leg, closest to the skin. It splits below the fetlock and attaches to both sides of the pastern (P1 and P2). Supports the fetlock as the leg takes weight and works like a spring, storing energy and giving it back as the leg leaves the ground.
Front: Comes from a muscle at the back of the forearm. The radial check ligament joins it above the knee. Hind: Almost all tendon, with very little muscle. It caps the point of the hock, then runs down the cannon.
Deep Digital Flexor Tendon
Deep digital flexor tendon (DDFT). Under the superficial flexor at the back of the leg. It passes through the superficial flexor's split at the pastern, runs over the navicular bone and attaches to the underside of the coffin bone (P3). Flexes the coffin joint and helps support the fetlock and pastern as the leg loads.
Front: Comes from three muscle heads behind the forearm. The subcarpal check ligament joins it in the upper cannon. Hind: The subtarsal check ligament joins it below the hock.
Radial Check Ligament
Superior check ligament, accessory ligament of the SDFT. Front leg only. From the back of the radius, just above the knee, to the superficial flexor tendon. Anchors the superficial flexor to bone so the tendon holds load while its muscle rests. Part of the stay apparatus that lets a horse stand with little muscle effort.
Front: Present in the front leg only. Hind: No hind equivalent. The hind superficial flexor is almost all tendon, so there is no muscle to protect.
Subcarpal Check Ligament
Inferior check ligament, accessory ligament of the DDFT. Front leg. Continues from the ligament at the back of the knee and joins the deep flexor tendon in the upper cannon. Limits how far the deep flexor tendon can stretch and takes load off its muscle. Part of the stay apparatus.
Front: Short, wide and strong. Hind: The hind version is the subtarsal check ligament.
Subtarsal Check Ligament
Accessory ligament of the DDFT, hind limb. Hind leg. From the back of the hock to the deep flexor tendon. Does the same job as the subcarpal check ligament in front: it limits stretch of the deep flexor tendon.
Front: The front version is the subcarpal check ligament. Hind: Thinner and more variable than the front one, and missing altogether in a minority of horses.
Suspensory Ligament
Interosseous medius (third interosseous muscle). Starts at the top back of the cannon, lies in the groove between the splint bones and splits into two branches in the lower cannon. Each branch attaches to a sesamoid bone at the back of the fetlock, then wraps forward to join the main extensor tendon. The main support of the fetlock. It stops the fetlock sinking too far as the leg takes weight, and with the sesamoid bones and the ligaments below them it forms the suspensory apparatus.
Front: Starts from the top of the cannon and the lower row of knee bones. Hind: Starts just below the hock. Thinner and longer than in front.
What changes between the front and hind leg
Below the knee and hock the two legs look alike. These are the differences worth knowing.
| Front limb | Hind limb | |
|---|---|---|
| Check ligaments | Two. The radial check holds the superficial flexor and the subcarpal check holds the deep flexor. | One. The subtarsal check holds the deep flexor. It is thinner and sometimes missing. |
| Lateral extensor | Runs its own course and ends on the long pastern bone (P1). | Merges into the main extensor in the upper cannon. |
| Superficial flexor | Has a real muscle in the forearm, which is why it needs a check ligament. | Almost pure tendon. It caps the point of the hock on its way down. |
| Suspensory ligament | Starts at the knee and the top of the cannon. | Starts just below the hock. Thinner and longer. |
| Resting the leg | Check ligaments and the suspensory apparatus hold the joints with little muscle work. | The kneecap locks the stifle, and the reciprocal apparatus makes stifle and hock move together. |
| Typical injuries | Bowed tendons and check ligament injuries are seen most often in front legs. | Proximal suspensory injury is the classic hind limb problem, especially in dressage horses. |
How to feel the tendons on your own horse
A daily leg check takes a minute and is the best way to catch a tendon or ligament problem early.
1. Start at the top
With the horse standing square, put your hand at the back of the knee or hock and run it slowly down the back of the cannon to the fetlock. Feel for heat, a soft puffy area or a curve in the outline.
2. Compare both legs
Do the same on the opposite leg at the same height. A small difference between legs tells you more than any single feel. Front with front, hind with hind.
3. Lift the foot
Pick the foot up so the tendons slacken. Now you can roll the superficial and deep flexor between finger and thumb and follow each one down. Press gently. A flinch at one spot is worth noting.
4. Check the branches
Just above the fetlock, feel the suspensory branches on the inside and outside of the leg, then check the digital pulse at the back of the pastern. Do this daily while your horse is sound so you know what normal feels like.
At the back of the cannon, from the skin inwards: Superficial flexor, Deep flexor, Check ligament (upper cannon), Suspensory ligament, Cannon bone.
Where tendon and ligament injuries happen
Knowing which structure sits where helps you describe what you find and understand what your vet tells you after a scan.
Bowed tendon
Superficial flexor. Where: Usually mid-cannon, front leg. Who: Racehorses, eventers and show jumpers. Signs: Heat, swelling and a bow on the back of the leg. Lameness may ease quickly even though the tendon is still damaged.
Suspensory desmitis
Suspensory ligament. Where: The top (proximal), the body or the branches. Who: Hind proximal injury in dressage horses and straight-hocked horses. Signs: Lameness or poor performance, sometimes with no swelling you can feel, because the top of the ligament sits between the splint bones.
Check ligament injury
Subcarpal check ligament. Where: Upper third of the front cannon. Who: Ponies, warmbloods and older horses. Signs: Swelling in the upper cannon, usually in one leg, with mild to marked lameness.
Deep flexor and sheath injury
Deep digital flexor tendon. Where: In the tendon sheath around and below the fetlock, or inside the hoof. Who: Any sport horse. Foot lesions are often found on MRI. Signs: A swollen tendon sheath at the back of the fetlock, or lameness that blocks to the foot.
New heat, swelling or pain on the back of the leg? Stop work and call your vet, even if the horse looks sound. Ultrasound confirms which structure is hurt and how badly. As a guide, tendons take around 6 months to heal and ligaments 8 to 9 months, and re-injury is common if work comes back too soon.
First aid and vitals · Lameness guide
Study the rest of the leg
Interactive Horse Skeleton
Find the bones these tendons attach to, from the radius to the coffin bone.
Interactive Horse Muscles
See the forearm and gaskin muscles the flexors and extensors come from.
Equine lameness, step by step
How vets localize lameness, including the nerve blocks that point to a tendon or ligament.
Navicular: the current consensus
Where the deep flexor tendon runs over the navicular bone and why that area matters.
Splint bone injuries
The splint bones frame the suspensory ligament. Learn how injuries there affect it.
10 common causes of lameness
Where tendon and ligament injuries sit among the problems pleasure horses face most.
Turn this diagram into exam-ready recall
Tendon and ligament injuries sit behind many lameness cases. Keep building on this diagram with our lameness flashcards.
Horse leg tendons and ligaments: common questions
What is the difference between a tendon and a ligament in a horse's leg?
A tendon joins a muscle to a bone and moves a joint when the muscle contracts. A ligament joins bone to bone, or bone to tendon in the case of check ligaments, and limits or supports movement. The flexor and extensor tendons move the lower leg; the suspensory and check ligaments hold it up.
Which tendons and ligaments run down the back of the cannon?
From the skin inwards: the superficial digital flexor tendon, the deep digital flexor tendon, the check ligament that joins the deep flexor in the upper cannon, and the suspensory ligament lying against the bone between the splint bones.
What is a bowed tendon?
A bowed tendon is an injury to the superficial digital flexor tendon. Swelling makes the back of the leg curve outwards like a bow. It is most common mid-cannon in a front leg and in horses that gallop and jump. It needs a vet and an ultrasound scan, and re-injury is common.
What does the suspensory ligament do?
It is the main support of the fetlock. It starts at the top of the cannon, splits into two branches that attach to the sesamoid bones, then joins the extensor tendon at the front. When the leg takes weight it stops the fetlock sinking too far.
Why does the front leg have two check ligaments and the hind leg only one?
Check ligaments let a tendon hold load while its muscle rests. In the front leg both flexors have real muscles, so both get a check ligament. The hind superficial flexor is almost all tendon, so it needs none. The hind deep flexor has the subtarsal check ligament, which is thinner and sometimes missing.
What do the extensor tendons do?
The main and lateral extensor tendons run down the front and outside of the leg and straighten the joints below the knee or hock, bringing the toe forward as the leg swings. In the hind leg the lateral extensor merges into the main extensor in the upper cannon.
How long does a tendon or ligament injury take to heal?
As a guide, tendons take around 6 months and ligaments 8 to 9 months, often longer for severe injuries. Healing is monitored with repeat ultrasound scans and a controlled exercise plan from your vet. Healed tissue is weaker than the original, so re-injury is common.
How does the label quiz work?
Choose Label it, tap a name in the word bank, then tap the blank line it belongs on. On a computer you can also drag names onto the lines. Press Check to see your score out of 13. Find it gives you 10 prompts to locate on the diagram. Your best scores are saved on this device only.
For education only. This diagram is simplified and does not replace an examination by your veterinarian.