backup og meta

What is the Achilles Heel?

Medically reviewed by January Velasco, MD · General Practitioner

Written by Dan Navarro · Updated Jul 18, 2022

    What is the Achilles Heel?

    Have you ever wondered why our lower extremities, particularly our legs and feet, can endure significant stress levels whenever we’re doing active tasks like running, walking, and jumping? We can think of a couple of factors, but one of the known reasons is our Achilles tendon, also known as our Achilles heel. What is the Achilles Heel? 

    What is the Achilles Heel?

    The Achilles tendon, also known as the Achilles heel and the calcaneal tendon, is considered the thickest and strongest tendon in our body. It is connected to the back of the leg muscles – the gastrocnemius and soleus muscle – on one end and tucked inside the calcaneus or heel bone on the other.

    Looking at the Achilles tendon, you can see how its width gets shorter as it approaches the shin bone, or tibia. This is because the end of the tendon at the heel rotates inward at 90 degrees. The tendon is connected to connective tissue in the calf region, providing support with the elasticity of up to two to three centimeters.

    How does this tendon function? Let’s say you’re doing an intensive task that requires footwork. In this case, both the gastrocnemius and soleus muscle will contract and bring force to the tendon as the foot pushes forward. On the other end, the paratenon will give support to the tendon as the feet move.

    Behind the Name “Achilles Heel”

    Fans of Greek mythology might be familiar with the story of the Achilles Heel. How does this relate to that part of the lower leg?

    According to myth, Achilles was a Greek demi-god, having a mortal father and a goddess as his mother. Like many gods and demi-gods, Achilles was invulnerable or immune to damage. However, in the case of Achilles, a small area of his heel was considered his only weak point and eventually lead to his demise in battle.

    The story of how the term “Achilles Heel” was used in medicine is just as complex as the myth of Achilles.

    In the past, it was known as “tendo Magnus” and “chorda Hippocratus,”. Later on, the legend of Achilles was associated with injuries to that tendon as medical experts from the 15th to 17th century observed how a damaged heel tendon weakens the person, hinders mobility, or can be hard to cure. 

    Thus, medical circles refer to the heel tendon as the Achilles or calcaneal tendon.

    Common Injuries of the Achilles Heel

    Injuries in the Achilles tendon may be caused by several factors, including stress from intense activities, ill-fitting shoes, friction on the tendon due to a growing heel bone, and sudden pressure during exercise and other tasks. This is especially true for people who participate in dynamic and active sports like basketball, boxing, or track and field which place plenty of stress on the feet and ankles.

    Listed below are the common injuries that your Achilles heel may experience:

    Achilles Tendonitis

    This condition refers to inflammation or swelling of the Achilles tendon. People with this condition may experience leg weakness, pain and inflammation, and stiffness in the affected heel area.


    This is a less severe condition involving the bursa or fluid-filled sac that provides a cushion and minimizes friction when pressure is applied to the heel.


    A ruptured or torn tendon is more common that you think. People who are not physically well-conditioned or have existing joint conditions (e.g. gouty arthritis) may be more prone to tendon ruptures.

    Symptoms of tendon ruptures include a feeling of snapping on the tendon, alongside intense ankle pain, swelling, and difficulty in relying on your toes when moving.


    Commonly associated with aging and repetitive movements (or overuse), this condition involves collagen degeneration. Since tendons are made up of collagen, this makes the Achilles tendon more susceptible to injury.

    Symptoms of tendinosis include inflammation around the tendon, pain that worsens the more you move, joint stiffness, and decreased flexibility and movement of the affected joint.

    Achilles Paratendinosis

    This condition occurs with or without tendonitis. However, this one concerns the swelling of the paratenon, a type of connective tissue found around the Achilles tendon.

    Treating Achilles Heel Injuries

    Dealing with injuries in the Achilles tendon depends on the type and severity of the injury. However, there are common remedies that you can do to relieve the pain and swelling. Here are some of these common treatments for injuries to the Achilles heel.

    1. R.I.C.E. When applying first aid, remember to: REST the limb, apply ICE and COMPRESSION to the affected area, and ELEVATE the limb.
    2. Splints and Cast. For injuries that result in difficulty in movement, you may need a cast or splint for the injured tendon to provide relaxation and healing for a certain period.
    3. Non-steroidal anti-inflammatory drugs (NSAIDs). The injured patient may take ibuprofen and similar medications to minimize the pain and swelling brought by the injured tendon.
    4. Physical therapy. This includes exercises and massages that could strengthen parts of the feet, such as the ankles, heel, and calf.
    5. Surgical treatment. Severe injuries such as a ruptured tendon may require surgical procedures and healing using a cast for a couple of months for the tendon to heal.


    What is Achilles Heel? It is named after the mythical half-human, half-immortal Achilles, whose heel was his weakness and led to the endpoint of his life. The Achilles heel or Achilles tendon somewhat has the same effect on us when it is injured or strained. 

    Because this tendon provides force and strength during intense activities with footwork, we need to take care of our feet to prevent any form of injury that may lead to a worsening condition. Discipline is also crucial, so it’s also vital for us to know our limits and rest whenever possible. It’s through these that we may be able to continue our lives with comfort and ease.

    Learn more about Musculoskeletal Pain here


    Hello Health Group does not provide medical advice, diagnosis or treatment.

    Medically reviewed by

    January Velasco, MD

    General Practitioner

    Written by Dan Navarro · Updated Jul 18, 2022

    advertisement iconadvertisement

    Was this article helpful?

    advertisement iconadvertisement
    advertisement iconadvertisement