Tendinopathy of the Achilles tendon

Anatomy

The calf muscle (called the triceps surae) is the large muscle on the back of the lower leg. It has two main parts:

• the gastrocnemius muscle, which attaches above the knee to the thigh bone (femur), and

• the soleus muscle, which attaches lower down to the fibula (the smaller bone of the lower leg).

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Both muscles join together to form the Achilles tendon, which attaches to the heel bone. This tendon also connects with a structure under the foot called the plantar fascia, helping with walking, running, and jumping.

What is Tendinopathy?

A tendon is the tough band that connects a muscle to a bone, allowing movement by transferring the muscle’s force. When a tendon becomes inflamed, irritated, or overloaded, we call it tendinopathy.

Normally, inflammation is a natural healing response — blood vessels widen to bring nutrients and repair cells to the injured area. But if the tendon is overloaded repeatedly, the biomechanics is poor or heals too slowly, the damage can become chronic (long-lasting), leading to ongoing pain and stiffness.

Causes of Tendinopathy

Tendinopathy usually happens because of mechanical stress or overuse — small, repeated injuries to the same spot over time. It’s common in athletes, but also in people who exercise recreationally or have physically demanding jobs.

Main causes include:

• Poor or worn-out shoes

• Muscle imbalances

• Running on uneven ground (especially always on one side of the road)

• No warm-up before training

• Sudden change in sport or training intensity

• Poor training plan or recovery time

• Poor balance

• General diseases like diabetes, gout, thyroid problems, lupus, rheumatoid arthritis, or inflammatory bowel diseases

• Dehydration

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Symptoms

The usual signs of inflammation are:

• Pain

• Redness

• Swelling

• Warmth around the tendon

Tendon pain often increases during rest, such as at night, and eases after movement or warming up. This can be misleading — people think the tendon “got better,” return to activity, and actually cause more damage. Over time, this can lead to degeneration (tendinosis) or even a complete tendon tear.

⚠️ A common myth: pain in the Achilles tendon should be “run through.” This is wrong — it can worsen the condition.

The stiffness you feel around an injured tendon is your body’s way of protecting it from further damage.

Diagnosis

A thorough interview and manual examination by a physiotherapist or doctor are usually enough to diagnose tendinopathy.

If there’s uncertainty or a large injury (especially in athletes), an ultrasound (USG) is used to see how much of the tendon is damaged and to plan treatment. X-rays (RTG) are not helpful because they don’t show soft tissues like tendons.

Physiotherapy

Successful recovery requires active participation from the patient. First, it’s essential to reduce the load on the injured tendon — either by resting, lowering activity intensity, or switching to a different type of exercise.

If it’s work-related, it may help to temporarily change your tasks. It’s also important to correct all the contributing factors mentioned earlier (like bad shoes etc.).

For Achilles tendon problems, raising the heel slightly can reduce tension on the tendon and support healing — but only when advised by a professional.

The key part of therapy is gradual loading:

• Perform pain-free exercises that lightly stress the tendon.

• Over time, increase the load step by step.

• This helps the tendon rebuild strong collagen fibers and adapt to future stress.

Completely avoiding movement is a mistake — tendons need controlled stress to heal properly. But too much load too soon can cause re-injury and start the process over again.

Effective physiotherapy techniques include:

• Manual therapy (hands-on work on muscles, fascia and joints)

• Deep tissue and cross-friction massage

• Stretching and mobility exercises

• Kinesiology taping or flossing 

• Shockwave therapy

  
  

Treatment

In addition to physiotherapy, some nutritional support can help:

• Collagen supplements

• Vitamin C

• Minerals (especially magnesium and zinc)

Sometimes, tendon problems can be linked to poor gut health, which affects how nutrients are absorbed — this can slow tendon healing.

If the problem becomes chronic, more direct treatments may be considered, such as:

• Platelet-rich plasma (PRP) injections — injecting your own blood plasma rich in healing cells directly into the damaged area to speed up repair.

• Corticosteroid injections — can quickly remove inflammation and pain, but they stop the natural healing process and may weaken the tendon in the long run. Such treatment must always be discussed with an orthopedic doctor.

Many people use anti-inflammatory pills (NSAIDs) because they’re easy to buy. While they may reduce pain, they don’t speed up healing and can even mask the problem, leading to more damage since the pain warning is gone. Overuse of these medications can also cause side effects.

The best approach is to see a physiotherapist early, before the problem becomes chronic.

References

1. Targońska-Stępniak B., Stępniak C., Majdan M. Tendinopathies, Medycyna po Dyplomie, 2012.

2. Strojek K. et al. Etiology and Pathomechanics of Achilles Tendon Injuries, Journal of Education, Health and Sport, 2016.

3. Dziak A. Sports Injuries and Damage, Acta Clinica, 2001.

4. Łukasik P. et al. Achilles Tendon Injuries in Active People, Med Sport, 2002