The Achilles tendon joins your calf muscles to your heel bone. This tendon lifts your heel off the ground during activity. Damage to the Achilles tendon is a common concern. Conditions include bursitis, tendinitis, tendinosis and tendon rupture.
The Achilles (uh-KILL-ease) tendon is a band of tissue in the back of your leg. This tendon links your heel bone (calcaneus, pronounced cal-KAY-nee-us) to your calf muscles. It’s also called the calcaneal tendon.
You have two Achilles tendons, one in each leg. The Achilles tendons are the strongest and biggest tendons in your body. The Achilles averages about 15 centimeters (6 inches) in length, but it’s up to 26 centimeters (10 inches) long in some people.
Achilles tendons can handle about four times a person’s body weight. But people commonly experience Achilles tendon injuries because of the stress put on this tendon. Almost 1 in 4 athletes have an Achilles tendon injury during their lifetime.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
The Achilles tendon, also called the heel cord, helps lift your heel off the ground. You use this tendon when you:
The Achilles tendon starts in the middle of your calf and extends down to your heel. It connects your calf muscles (gastrocnemius and soleus muscles) in the back of your lower leg to the heel bone in your foot.
The gastrocnemius muscle has two heads that crisscross the knee joint. This muscle flexes your knee and ankle. The soleus muscle flexes your foot to point your toes downward.
Strong collagen fibers make up the Achilles tendon. As with other tendons, a layer of paratenon cells surround each layer of the Achilles. The paratenon layer provides blood flow to the tendon and lubricates its movement.
Healthcare providers often classify parts of the Achilles as the:
Bursae, small sacs of fluid, cushion your Achilles tendon at its insertion point into your heel. The bursae aren’t part of the Achilles itself, but injuries to the tendon often affect them.
Problems involving the Achilles tendon are called Achilles tendinopathy. Achilles tendon disorders include:
Your healthcare provider first does a physical exam to check for Achilles tendinopathy. Your provider looks for Achilles tendon pain when they move or press your tendon.
They examine the area around your heel and lower leg for:
Your healthcare provider may also use tests including:
Healthcare providers usually treat calcaneal tendon problems with nonsurgical treatments, including:
If you completely rupture your Achilles tendon, you may need surgery as soon as possible. Your health provider makes a recommendation based on your overall health, age, medical history and seriousness of the tear. Health providers often treat partial Achilles tendon ruptures with nonsurgical treatments.
To help reduce your risk of Achilles tendon problems:
If you still experience pain and symptoms three to six months after you start treatment, you should talk to a healthcare provider. In some cases, severe Achilles tendonitis can lead to an Achilles tendon rupture, which requires surgery.
A note from Cleveland Clinic
Your Achilles tendon connects your calf muscles to your heel bone. Though the Achilles tendon is strong, people frequently experience Achilles tendon injuries. Conditions that impact the Achilles tendon include bursitis, tendinitis, tendinosis and tendon rupture. Providers treat most Achilles tendon issues nonsurgically, though tendon rupture often requires surgery. With proper rest and activity, many Achilles tendon injuries heal within three to six months.
Last reviewed by a Cleveland Clinic medical professional on 09/24/2021.
Learn more about our editorial process.