Tendonitis: The Overdiagnosed, Misunderstood Injury
Tendonitis is diagnosed way too often without a real understanding of what tendon injuries actually are. It’s like blaming the WiFi every time your Netflix buffers—sure, it might be the issue, but maybe it’s time to check your router (or your ISP… or the fact that 12 devices are streaming simultaneously). Similarly, when it comes to pain, we need to stop assuming it’s always just “tendonitis” and start looking deeper at what’s really going on.
Muscles vs. Tendons: Not the Same Thing
Muscles and tendons aren’t interchangeable. A muscle is a contractile tissue—it shortens, lengthens, and generates force. A tendon, on the other hand, is a load-dependent structure anchoring the muscle to a bone. It doesn’t contract on its own; it transmits force so we can take that muscle contraction and create movement. That means they don’t just get injured differently, they also need to be treated differently. Yet, “tendonitis” gets thrown around like an all-encompassing term anytime someone has pain near a tendon.
The Real Culprit: Load Tolerance
Tendon injuries don’t happen in a vacuum. They are directly related to load tolerance—how much stress the tendon can handle versus how much stress it’s actually experiencing. If you exceed that threshold, irritation happens. And the kicker? The intensity of the activity doesn’t necessarily matter as much as the change in load over time.
Take the classic “weekend warrior” scenario: you haven’t run in months, but suddenly decide to start training for a marathon. Or maybe you move to a hilly city where every errand feels like a mini mountain trek. Or you’re recovering from an injury, took some time off, and then jumped right back into heavy lifting. These changes in load, not just the activity itself, are what set tendons up for irritation.
Tendon-related pain doesn’t hit like a lightning bolt. It creeps in. It starts as a mild irritation that you feel after a long walk or a hike, then escalates. The more you push without addressing the underlying issue, the more sensitive the tendon becomes—until eventually, even walking around the house can be aggravating. Contrast that with muscle injuries, which tend to happen in a single moment. You don’t gradually tear a hamstring—you feel that sharp, unmistakable pull mid-sprint.
What the Research is Missing
Recently, a new summary on Achilles tendonitis was published for physical therapists, aiming to clarify the diagnosis and treatment process. And while I love a good research update, I couldn’t help but notice some glaring omissions—like, oh, I don’t know, mechanism of injury or load pattern. How do we expect to treat something effectively if we’re not asking the right questions?
Even worse, the recommendations were entirely Achilles-focused. Nowhere in the discussion was there any mention of how other parts of the body might be playing a role. If a tendon injury is fundamentally a load issue, why are we not talking about ways to redistribute that load elsewhere? For example, in runners with Achilles tendonitis, are they overloading their calves because their glutes aren’t fully doing their job? If that’s the case, no amount of calf strengthening is going to keep them from getting re-injured once they start running again.
A Smarter Approach to Tendon Health
If we actually want to prevent and rehab tendon injuries properly, we need to do more than just slap a “tendonitis” label on it and prescribe calf raises. We need to:
Assess Load Patterns – What changed in the person’s activity that could be stressing the tendon beyond its capacity?
Look Beyond the Pain Site – Is the issue really in the tendon, or is it compensating for something else not pulling its weight (literally)?
Train Smarter, Not Just Harder – Strengthening is crucial, but it needs to be done in a way that improves overall movement patterns, not just the isolated tendon.
At the end of the day, tendon injuries are about more than just the tendon itself. They’re about how the entire system works together—or doesn’t. So, if you’ve been slapped with a tendonitis diagnosis, don’t just focus on treating the symptom. Look at the big picture. Your tendons (and your future self) will thank you.
