What is the Achilles Tendon?

By Tim Wall MS/ATC

What is the Achilles Tendon?  JOI Rehab has the answer for you. 

The Achilles tendon is the thick tendon in the back of the ankle which runs from the middle of the lower leg to the heel. This tendon connects the calf complex to the heel bone (calcaneus) and allows for the foot to go into plantar flexion. This is the motion of lifting your heel and standing up on to your toes.  The calf muscles are the gastrocnemius and the soleus.

Achilles tendinitis is an inflammation of the tendon, which can cause pain, swelling, and heat in the tendon and its attachment to bone.

JOI Rehab What is the Achilles Tendon?

What is the Achilles Tendon?

Achilles tendinitis is an injury typically stemming from overuse, that will cause pain and inflammation in the tendon. This is a very active muscle group and tendon for anyone who is involved in sports. However, anyone who is on their feet for longs periods of time throughout the day will also feel similar effects.

Achilles Tendinitis

Achilles tendinitis is an inflammation in the Achilles tendon, which attaches the calf complex to the heel. This condition can happen acutely or over time. In either case, it is important to treat Achilles tendinitis quickly and not let it become chronic. This can further weaken the tendon and limit function.

What is the Achilles Tendon?

Achilles tendon injures

Causes of Achilles Tendinitis

As mentioned previously, Achilles tendinitis is usually caused by repetitive movements such as running, jumping and pushing up onto the toes frequently. All of these movements put strong tension on the Achilles tendon. The symptoms of this condition can come immediately after an acute injury or can come gradually after repetitive use of the calf or tendon.

Many times this condition can occur due to overtraining or pushing oneself too quickly when beginning walking, running or jumping activities. Other common external forces that can cause this are:

  • exercising on incorrect surfaces
  • poor footwear
  • training on an incline
  • changing surfaces (grass, concrete, sand, clay)

This condition can occur due to degenerative changes in the tendon from overtraining over long periods of time or from having tightness in the calf muscles. In any case, it is important to seek medical treatment as quickly as possible to limit chronic inflammation, leading to Achilles tendinosis.

Signs and Symptoms of Achilles Tendinitis

Pain and stiffness in the tendon are usually the first indications that you have an injury to your Achilles tendon. The pain is typically worse in the morning and can get better throughout the day, as more blood flows to the tendon. You may also notice when pain occurs in the Achilles tendon when you are pushing off of your toes when walking, running or jumping. However, your strength should not be limited by this injury. Heat and swelling in the tendon can also occur with more acute injuries to the tendon.

Diagnosis of Achilles Tendonitis

Typically, subjective history of the injury to the Achilles tendon and sign and symptoms are sufficient for the diagnosis of tendinitis. Manual tests, strength tests, palpation and flexibility tests are also performed to further diagnose tendinitis, tendinosis or possible tearing. An MRI or CT scan may be performed in chronic cases to determine the extent of the injury to the tendon and rule out the tearing of the Achilles tendon.

Treatment of Achilles Tendinitis

The treatment of acute Achilles tendinitis and chronic Achilles tendinosis will differ because of acute pain or weakening of the tendon from chronic compromised blood flow. In the treatment of an acute case of Achilles tendinitis, it is important to apply the R.I.C.E. method to reduce immediate inflammation and pain in the tendon.

R.I.C.E. stands for:

  • Rest
  • Ice
  • Compression
  • Elevation

This method will help to decrease the swelling and pain associated with the body’s inflammatory response to injury.  It is also important to limit activities that stress or irritate the tendon. This treatment of Achilles tendinitis may sometime require the use of an immobilizing boot.

Using a towel to apply a light stretch to the calf will improve blood flow and prevent tightening. As the Achilles tendon becomes less painful, more aggressive stretching and strengthening exercises can begin.  Exercises for the ankle can help to reduce the likelihood of Achilles tendinitis becoming a recurrent problem.

Calf and Achilles Stretch on a Board 

For cases of Achilles tendinosis (chronic Achilles tendinitis), heat may be a more beneficial modality.  It can improve the blood flow to the tendon. More aggressive calf stretching and eccentric strength exercises are the best approaches for strengthening the weakened tendon. Eccentric strengthening is a lengthening contraction of the calf.  An example is standing on the toes and slowly lowering the heel to put tension on the Achilles tendon. Massage or soft tissue mobilization to the tendon will also help improve blood flow and decrease stiffness in the tendon. This allows for slow stretching of the Achilles tendon and will help to build strength over time while decreasing irritation to the tendon.

Calf Stretch by JOI Rehab

Calf Stretching

Achilles Tendon Injuries 

It is important to note that the symptoms of tendinitis can get worse prior to improving even with treatment and can take up to 12 weeks to fully resolve. Therefore, it is essential to keep up with treatment to fully heal and return to all daily activities. If you want to learn more about the Achilles Tendon, please watch this video by Dr. Turner Vosseller.

Related Article: Achilles Tendon Rupture.


Finally, if you are interested in scheduling an appointment at JOI Rehab for physical therapy, call 904-858-7045.  To schedule with a JOI Foot and Ankle Specialist, you can schedule online or call 904-JOI-2000.

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