Achilles Tendinitis: Overview

Achilles Tendinitis: Overview

Achilles tendinitis, or tendinopathy, is a common condition that causes pain and swelling on the back of the heel. The incidence of either Achilles tendinitis or Achilles tendon rupture is about 250,000 per year in the United States. Around 6% of the general population reports some type of achilles tendon pain during their lifetime, with 1/3 of those having what is called insertional Achilles tendinopathy.

There are risk factors that can put someone at a higher risk of getting Achilles tendinitis. Some medical risk factors are having diabetes, taking steroids, or taking certain antibiotics for a long period of time. Being overweight can cause Achilles tendon problems as well due to the extra weight placed on the tendon during normal activity. Genetics plays a large role, with family history raising the risk almost fivefold. Males tend to get it more than females and risk increases with age. Also, changes in physical training patterns, repetitive overuse, and certain types of shoes can contribute to the risk of Achilles tendinitis.

Here is an overview of the anatomy to better understand this condition. The Achilles tendon on the back of the ankle is the largest and strongest tendon in the body. It provides the main push-off strength when someone is walking or running. The 2 large muscles on the back of the lower leg, the gastrocnemius, also called the gastroc for short, and the soleus, both attach to the Achilles tendon. The tendon then inserts on the heel bone or calcaneus. When these muscles contract, they pull on the Achilles tendon, moving the heel up and pointing the toes down. Surprisingly, just normal walking can place up to 3x a person's body weight through their Achilles tendon, while running can place over 10x their body weight on the tendon with each push-off of the leg.

Tendinitis means inflammation of a tendon. In the Achilles tendon, this can occur in 2 different locations. It can be in the mid-substance of the tendon itself, or it can be at the insertion, where it attaches to the heel bone. Some patients may get Achilles tendinitis from a one-time injury, while others may develop it over time. If someone is having pain in the back of their heel or ankle, the problem could be their Achilles tendon and it should be looked at by a healthcare provider.