Achilles Tendinosis

Contributed by Darrin Bright, MD


There are two main muscles that form the belly our calf – the gastrocnemius and the soleus.  The thickened portion of a muscle that attaches to a bone is called the tendon.  In this case the Achilles tendon is the thickened part of the gastrocnemius and soleus muscles that attaches to the heel bone.  It is an area that is susceptible to repetitive use injury in endurance athletes largely due to the less than optimal blood flow to the area.  Under too much stress the tendon starts to become inflamed and eventually breakdown, leading to scarring and fibrosis.  The concept of inflammation leading to scarring and degeneration of a tendon is a new and emerging concept in sports medicine.  Historically, we thought all injuries were caused by inflammation.  However, recent studies have taken tissue samples from affected tendons and found that there wasn’t a lot of inflammation present after 4-6 weeks.  The initial inflammation had been replaced by scarring and fibrosis.  As a result we no longer refer to this process as tendonitis (-itis refers to inflammation) but rather tendinosis – a chronic tendon injury associated with degeneration and scarring without inflammation.  As you can imagine this significantly impacts that way we need to treat these injuries.  Most people I see are surprised that the mega-doses of NSAIDs (Advil, Aleve, etc) they have been taking aren’t helping.  With this new understanding of tendinosis we can see why.


Achilles tendinosis represents the most common foot and ankle problem in runners over the age of 35.  People suffering from Achilles tendinosis will typically experience pain is the Achilles tendon approximately 1 inch above its insertion on the heel bone.  This pain will frequently be accompanied by swelling of the tendon.  Some individuals will also experience some “creaking” of the tendon when they move the ankle.  Affected individuals will have pain associated with running and sometimes walking.  Stairs and climbing hills will frequently make symptoms worse.  As with most cases of tendinosis you may find that it seems to loosen up once you get going and then gets worse towards the end of the workout and afterwards.

Risk Factors

Certainly having tight calves can predispose to this condition.  However, other risk factors include mid-foot striking, increasing mileage too quickly, hit intensity intervals, hill workouts, and improper fitting running or walking shoes.

Prevention & Treatment

Make sure you have been properly fit for running and walking shoes.  Incorporate calf stretching and strengthening exercises into your regular routine.  

If you develop Achilles tendinosis take a few days off and focus on icing and stretching.  Once symptoms have improved it is OK to routine to running and walking as long as you aren’t limping.  When you start back into running and walking avoid hills and speed work until your symptoms have completely resolved.  If symptoms persist, it is recommended you see a sports medicine physician to help confirm the diagnosis and establish and effective treatment plan.

Darrin Bright, MD, is a family medicine and sports medicine physician with the MAX Sports at OhioHealth in Columbus, Ohio.   He is an avid marathon runner who serves as the director of The Runner’s Clinic and medical director for the Columbus Marathon, Capital City Half Marathon, and Emerald City Half Marathon.


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