Breakthroughs in our Understanding of Tendonitis

Tendons are actually the most common site for repetitive strain injury or RSI whether its tendonitis, epicondylitis, or tenosynovitis. Tendonitis can also be a garbage diagnosis—tests do not reveal any other specific RSI, so a practitioner, for the sake of getting the patient treatment coverage, will attribute the pain to tendonitis. This causes huge problems for the patient, as we’ll see.

Scientists focusing on the tendons and repetitive tasks have uncovered a great deal of understanding on how RSIs spread beyond the original injury site. Their findings have been summarized in Pathology and Intervention in Musculoskeletal Rehabilitation, 2nd Edition. The following information comes from the chapter Repetitive Stress Pathology: Soft Tissue by Nancy N. Byl, Mary F. Barbe, and Jane Fedorzyck.

Recent studies focusing on the tendons in repetitive movement show the same tissue damage as with muscles: inflammation, tissue degeneration and disorganization, even necrosis. But biopsies of tendons and tendosynovial (fluid sheaths surrounding tendons) show collagen degradation as well, evidencing metabolic changes in addition to structural tissue damage. A further breakthrough comes in how the tendons adapt. When a muscle degenerates from overuse, the tendons associated with that muscle adapt to protect themselves from the muscular degeneration.  These adaptive responses are evident “after 13 weeks at a repetition rate of 2 hours per day, 3 days per week!"

What's worse, the way a tendon adapts to overuse is in direct contrast to how the muscles do. This can explain why so many patients don’t respond to the treatment guidelines. They need different, additional treatment to address tendon damage and muscle damage, as well as a longer recovery time, as tendons heal slowly if at all. Once damaged, tendons rarely return to their original strength and structure, making them even more susceptible to future damage. Studies show this remains true even if you stop the repetitive motion for 3 months, which suggests evidence as to why bracing alone doesn’t always work. There remains controversy whether tendons show any inflammation from repetitive use, but the authors speculate this may be because by the time the tissues are examined, the inflammatory cycle has advanced into tissue degeneration. This is important because the patient's lack of response to inflammatory treatments has been signaling no damage at the clinical level, when in fact it may mean the tissue has already died.

Now that we have the scientific evidence, let's work to integrate these discoveries into the treatment protocols. Whether top down or bottom up. What you can do in the mean time is direct your PCP or other treating physician to the book. Unfortunately, however, the challenge in determining causality remains. What came first: the tissue damage or the maladaptive biomechanical responses correlated with RSIs?

@JillGambaro is the author of The Truth About Carpal Tunnel Syndrome . She has lived with multiple repetitive strain injuries known as a “double crush” for over 15 years. A former board member of the Los Angeles Repetitive Strain Injury Support Group and the Cumulative Trauma Disorders Resource Network, Jill advocates for prevention, patient engagement and healthy playing for musicians through her Blog, Facebook and Twitter @IckyFingersMovi. Look for her upcoming documentary Icky Fingers.