Wednesday, 20 July 2011

Is Your Achilles Tendon (or other Tendon) Your Achilles' Heel?

The Painful Tendon

A tendon is a portion of connective tissue that links your muscle to bone.  These bands of tissue are prone to injury, and it is highly likely that you have experienced some form of tendon pain in your life.  Overuse shoulder injuries, tennis elbow, patellar tendinitis, and Achilles tendinitis are all common types of tendon pain that you may have encountered.  

RICE Principle- May not be effective for chronic tendon pain
But what exactly is going on with these damaged tendons?  Why do some symptomatic episodes get better in a matter of weeks, while others linger for months?  The answer comes down to what is happening at a cellular level, and where your pain is actually originating from.  These answers will not only surprise you, but it will drastically alter how you look at your injuries and how you manage them.  Surprisingly, your good friend, the “RICE” principle (Rest, Ice, Compress, Elevate), may not be as effective as you once thought. 

The Fallacy of Overuse

It is a well known fact that tendon pain originates from overuse, right?  The avid tennis player suffers from tennis elbow because he plays too much- it’s common sense.  It is common sense that appeals to my logic, but unfortunately it’s wrong (sometimes). 

In a 2005 review article published in the Journal of Medicine and Science in Sports, it was shown that the origin of chronic tendon pain likely does not come from overuse.  This paper references studies which described individuals who suffer from chronic tendon pain and who are also entirely inactive.  In addition, another study shows that physical activity was not correlated with the typical cellular changes that are associated with tendon pain.  The authors suggest, “that physical activity could be more important in provoking the symptoms than being the cause of the actual lesion” 

Thus, physical activity and overuse plays less of a roll than we once thought.  So should you be resting your injuries?  Maybe not, especially if it is a chronic problem.  

The Fallacy of Inflammation 

Popular consensus regarding the origins of tendon pain is as follows: the tendon is used so much that it becomes injured, inflammation follows, and subsequently pain is experienced.  This cascade is, in fact, fairly accurate, but for only half of the story.  While this sequence does describe what likely happens with an acute tendon injury, new research shows that chronically painful tendons show no signs of inflammation. 

The same 2005 paper describes how when histological studies were conducted on chronically painful tendons, normal levels of the inflammatory mediators called prostaglandins were found.  If inflammation was occurring, these prostaglandins would have been observed at high levels, but they were not.  In addition, genetic studies showed that there was no upregulation of the genes responsible for producing inflammation.  In other words, there were no signs of inflammation, and no signs of triggers for inflammation. 
These may be of no help with chronic tendon pain

Another more practically applicable study referenced in this paper looked at the use of piroxicam, an anti-inflammatory medication, in the treatment of chronic Achilles tendon pain.  Interestingly, it showed similar results to placebo, and now we know why!  There was no inflammation for the piroxicam to get rid of, so of course sugar pills were just as effective. 

This also brings us back to the “RICE” principal.  The ice, compression and elevation components are all designed to decrease inflammation.  But, if piroxicam was ineffective in treating a chronically painful tendon, it seems that these methods would also provide little help for the same reason. 

Tedinitits vs. Tendinosis 

If you have experienced some form of tendon pain and sought a diagnosis from a healthcare practitioner (or Dr. Google), it is likely that you have been labelled with tendinitis.  It is funny because generally speaking, medical jargon has a habit of labeling a patient’s affliction by simply restating what they experience- only in a fancy way.  So, if a patient comes in saying that they injured their tendon and they feel like it is inflamed, the healthcare practitioner would give them the diagnosis of tendinitis.  However, this tremendously insightful diagnosis literally means tendon inflammation (“tendin-” means tendon, “-itis” means inflammation).

 However, as we just learned, in a chronically painful tendon, there is no inflammation involved, so tendinitis is no longer appropriate.  To take the place of tendinitis, tendinosis is now used. 
Suffer from chronic wrist pain?  Inflammation may not be involved!

What’s Going on with Tendinosis 

Glutamate Molecule- the primary suspect with tendinosis pain
Research is somewhat in its infancy in understanding tendinosis, but there have been a few key discoveries.  First of all, the study referenced below shows that glutamate levels were much higher in chronically painful Achilles tendons compared to normal tendons.  Glutamate is a neurotransmitter that is highly associated with the perception of pain.  So, if you’re hurt, and you feel pain, glutamate is playing a role in getting that single from your injury to your brain.  So it seems with these cases of tendinosis, even though the chemical inflammation is gone, there still seems to be some form of neurological inflammation sending the perception of pain to your brain. 

A second interesting finding noted in this article is that there was higher levels of lactate in chronically painful tendons compared to normal tendons.  Lactate is what you accumulate in your muscles when you strenuously exercise.  This happens because there is not enough oxygen reaching the muscles to meet the imposed demands.  So, in the case of tendinosis, it is speculated that the high levels of lactate indicate decreased levels of oxygen reaching the area as a result of reduced blood flow. 

So, in summary, two things may be going on with tendinosis: (1) your painful tendon may not be getting enough blood flow and/ or oxygen, and (2) your brain may be getting a pain signal from the tendon despite a lack of inflammation. 

 What does this do to Treatment?

What these pieces of evidence show, first of all, is why you should not get discouraged if you currently have a chronic tendinosis.  If you have been resting, and trying to control the inflammation with medication and ice, it is no surprise that you have experienced limited success.  This paper shows us why the tried and true RICE principle of treatment for acute injuries simply does not apply to cases of tendinosis. 

So what can you do to help these cases of tendinosis?  The details will be in next week’s blog, but the answer almost seems counter-intuitive.  The two keys of treatment include; (1) increasing specific exercises that stress the damaged tendon (rather than resting), and (2) conducting the exercises into pain (rather than avoiding pain).  Stay tuned!


Alfredson, H. 2005. The chronic painful Achilles and patellar tendon: research on basic
biology and treatment. Scand J Med Sci Sports. 15: 252–259


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