Tendinitis: Background Information
As the understanding of tendon injuries has shifted paradigms over the years, so has the treatment style. While tendinopathy conditions were initially treated as inflammatory stages, treatment was built around addressing the inflammation in the tissue. Treatment involved icing, anti-inflammatory medications, bracing, and rest. As the research shifted towards identifying degeneration in the tendon instead of inflammation, eccentric exercises and instrument assisted soft tissue mobilizations (IASTM) became a primary focus of treatment. Eventually, the paradigm would shift again, revealing limited evidence behind both eccentrics and IASTM.
At this point, we still have not discussed arguably the most important topic for treating tendinopathy: Pain Science Education! Much of the research regarding pain that has come out over the last decade has shown the lack of correlation between pathological imaging findings and pain. Under an MRI or Ultrasound, a tendon may show degeneration or inflammation, but these findings don't relate to one's individual level of pain. Understanding the function of pain, it is clear that a single snapshot of the tendon at one point in time is not as important. For this reason, I promote the tissue irritability treatment strategy discussed further in this post.
Concentric, Eccentric, or Isometric Exercise?
When it comes to tendon strengthening, eccentrics have not shown to be any more effective than concentric exercises. In fact, isometrics have been shown to have a pain-modifying effect almost immediately! What appears to be most important with exercise selection is choosing the appropriate load at each phase. Isometrics tend to be more useful early in the treatment protocol with a gradual progression to concentric and eccentric based exercises.
How Does Tendinitis Develop?
While tendon pain may start with a specific event, it is more likely associated with a repetitive motion. For example, a single jump during a basketball game will not cause tendinitis, but rather jumping hundreds of times during a game may cause damage to the tendon if not properly trained. Tendons, like most tissues in the body, are adaptive. When regularly stimulated through exercise or movement, the muscle and tendon contract and stretch.
Return to Training Post-Tendon Injury
As a general rule, remember that slowly strengthening, then appropriately resting are two keys to a healthy tendon. If someone has been running two miles regularly and wants to increase the mileage to eight miles per day, slowly increase the training volume every week or two. Start with three miles per day, then progress up to four miles, and then five or six miles per day. Do not forget about rest! Rest is the component most often missed. As the volume of running increases, more rest days must be built into the training plan. Pre-emptively take a rest day between running days and always listen to subtle signals of soreness, discomfort, and pain that may indicate overtraining.
Using a Tissue Irritability Treatment Classification
Diagnosis of tissue irritability is essential to proper selection of the intervention type, frequency, load, intensity, duration and more. Immediately after the injury when experiencing high levels of pain, you don’t want to over-stress the tissue. During a physical therapist evaluation, the first step after diagnosis is to identify which stage your patient is currently experiencing. Try to determine if the pain is minimal, moderate, or severe and figure out how much activity is painful and limiting as well (i.e. all, common tasks, or only high-level activities).
For each treatment day, you need to match exercises according to the present irritability level. Even though there are three stages or phases of irritability for tendon injuries, this does not mean you have to experience all three of them. Each person experiences pain subjectively, and therefore seeks treatment on an individual timeframe. Understanding both the pathophysiology of tendon overuse injuries and pain neuroscience helps you identify that 'sweet spot' for treatment.
Below I provide an example of exercises used in each of the 3 phases for Achilles Tendinopathy.