Part 2: Getting Rid of Tendinosis

No Inflammation?

Last week's blog took a look at the main differences between a more acute tendon injury (tendinitis) vs. a chronic tendon pain (tendinosis).  How exciting was that?

In case you missed it, or are too lazy the go back and read it (which I would be), the key difference to keep in mind is that while tendinitis is associated with inflammation, tendonosis is not.  Therefore, your typical icing and anti-inflammatory medication will simply not do the job with a chronic tendon injury.   

Then how do you get rid of your pain?  To get this answer, we will go back to our 2005 study published in the Journal of Medicine and Science in Sports.

Study

This study took into consideration one of the most common types of chronic tendon pain- Achilles tendinosis.  A typical conservative treatment protocol for this type of injury often includes eccentric loading of the tendon.  Eccentric loading simple means taking your calve muscle from its shortened position to its longest position while under a load.  In other words, you would use your uninjured side to bring yourself onto your toes, and then slowly lower your heel to the ground using the injured side.  

 Here is a video of eccentric Achilles tendon loading:

http://www.youtube.com/watch?v=p2J7lZ0KQOw

This pilot study looked at 15 people who had not responded to previous conservative treatment (including rest, anti-inflammatory medication, orthotics, change in shoes, physical therapy).  Each of these individuals were so desperate that they were on a waiting list for surgery.  While they waited for their surgery, they completed one last ditch effort to rehab the painful tendon.  This is the protocol they followed:

• 3x15 repetitions of the eccentric Achilles tendon exercise 
• Repeated twice per day, 7 days a week, for 12 weeks 
• Did not avoid going into pain 
• If no pain was experienced, the number of reps were increased to create pain

After these 15 subjects completed the 12 week program, this is what they found:

• There was a significant decrease in pain  (81.2 to 4.8 on the VAS- a pain scale) 
• All 15 subjects were satisfied with their progress 
• In a long term follow up, only 1 subject showed recurrence and subsequently required surgery

These are absolutely amazing results.  While medication, changes in shoes, and physical therapy could not touch the pain, this simple 12 week exercise program almost entirely eliminated it.  These results were consistent with what was observed in the author’s clinic as 90/101 painful Achilles tendons showed positive response to this protocol. 

Why Eccentric Loading?

First of all, why is it important to eccentrically load the tendon?  Why can you not concentrically load it (i.e. just stress the tendon by going up on your toes) instead?  In a recent study referenced within this article, it was shown that:

•  81% of subjects were satisfied with their progress while eccentric loading
• 38% of subjects were satisfied with their progress with concentric loading

So, to get the best results, go with eccentric.  If you try it yourself on your healthy Achilles tendons, even you will see that the concentric motion is smooth and easy when compared to the shaky motion of eccentrically loading the tendon.   

How does Eccentric Loading Change Tissue?

  
There is no definitive answer to how eccentric loading changes tissue.  There is, however, three theories:

1. Increasing Tendon Strength:  The first logical theory is that by stressing the tendon, it will result in a stronger tendon.  However, if this is the reason why it works, then why would concentric loading not work?
2. Decreasing the Perception of Pain: This theory makes a little more sense than the previous idea.  As mentioned in my previous article, one interesting difference associated with a chronically painful tendon is that there is an apparent lack of inflammation, and high levels of a neurotransmitter for pain- glutamate.  Thus, it leads to the idea that the tendon may no longer be damaged, but your nervous system is still interpreting pain originating from this area.  With the stepwise increase in repetitions with the eccentric loading protocol, you are consistently training your tendons to tolerate more loading and more pain.  This theoretically trains your nervous system to recognize and process only normal levels of pain from that tendon.
3.  New Blood Vessels:  The final theory is associated with what is going on with blood vessels surrounding the chronically injured tendon.  As you may remember from my last article, there is an apparent decrease in blood flow within chronically injured tendons.  However, this also means that there is an increase in new blood vessels trying to penetrate the tendon along with associated nerves.  It is thought that these new nerves sprouting may be what is responsible for transmitting the inappropriately high levels of pain.  The theory is that the eccentric training regimen traumatically damages the blood vessels and subsequently decreases the amount of new nerves traveling into the tendon.

To test the 3rd theory, the sclorising agent Polidocanol was injected into the injured tendon.  This drug is normally used to treat itching, pain, and even varicose vessels.  It works by damaging blood vessels and causes them to shrink.  Thus, theoretically, if new blood vessels and the subsequent nerves were responsible for the pain experienced with tendinosis, then Polidocanol should stop the pain.  And, believe it or not, this is what was observed- both in the short and long term follow ups!
 

Not for Everybody 

First of all, it is important to note that this rehab protocol only seems to be effective when the painful portion is close to the muscle.  If it is close to the boney attachment, eccentric loading my not be helpful.  In this study, it was found that only 10 of 31 patients with insertional Achilles tendon pain were pain free and satisfied after their 12 weeks of rehab.  So, make sure you know what type of chronic tendon pain you have before you put your faith in eccentrics!

Closing 

First of all, keep in mind that the tissue and cellular biology behind the rehab of chronic tendon pain is in its infancy.  This article simply outlines ideas with some interesting yet nonetheless limited supporting research.  So take it all with a grain of salt.

However, what you can conclusively know from this research is that if your tendon pain has not resolved with the normal rest and anti-inflammatory measures after an extended period of time, then:

1. It is likely that your tendon is hurting for a reason other than inflammation (so it is time to lay off the rest and NSAIDs)
2. Conducting an eccentric loading protocol that stresses the tendon into a point of pain is definitely worth trying (especially before you consider surgery) 

References

Alfredson, H. 2005. The chronic painful Achilles and patellar tendon: research on basic

biology and treatment. Scand J Med Sci Sports. 15: 252–259