[#4] Why Your Tendon Pain Keeps Coming Back (And How to Fix It)

I focus on Dr. Jill Cook’s papers introducing the tendon pathology continuum from 2009 and her paper from 2016 revisiting this model with new evidence. Based on her papers, I’ll break down what tendinopathy is and how to actually improve it based on this updated model.

Main topics covered:

• Previous tendinitis definition
• Current understanding of tendinopathy
• What doesn’t work when treating tendinopathy
• Components of tendon rehab
• Tendon rehab timeline
• Role of injections and shockwave therapy in tendon rehab

References:

• Cook, J. L., & Purdam, C. R. (2009). Is tendon pathology a continuum? A pathology model to explain the clinical presentation of load-induced tendinopathy. British journal of sports medicine, 43(6), 409–416. https://doi.org/10.1136/bjsm.2008.051193
• Cook, J. L., Rio, E., Purdam, C. R., & Docking, S. I. (2016). Revisiting the continuum model of tendon pathology: what is its merit in clinical practice and research?. British journal of sports medicine, 50(19), 1187–1191. https://doi.org/10.1136/bjsports-2015-095422 
• Martin, R. L., Chimenti, R., Cuddeford, T., Houck, J., Matheson, J. W., McDonough, C. M., Paulseth, S., Wukich, D. K., & Carcia, C. R. (2018). Achilles Pain, Stiffness, and Muscle Power Deficits: Midportion Achilles Tendinopathy Revision 2018. The Journal of orthopaedic and sports physical therapy, 48(5), A1–A38. https://doi.org/10.2519/jospt.2018.0302
• Silbernagel, K. G., & Crossley, K. M. (2015). A Proposed Return-to-Sport Program for Patients With Midportion Achilles Tendinopathy: Rationale and Implementation. The Journal of orthopaedic and sports physical therapy, 45(11), 876–886. https://doi.org/10.2519/jospt.2015.5885
• Garzón, M., Balasch-Bernat, M., Cook, C., Ezzatvar, Y., Álvarez-Lliso, Ó., Dueñas, L., & Lluch, E. (2024). How long does tendinopathy last if left untreated? Natural history of the main tendinopathies affecting the upper and lower limb: A systematic review and meta-analysis of randomized controlled trials. Musculoskeletal science & practice, 72, 103103. https://doi.org/10.1016/j.msksp.2024.103103
• Malmgaard-Clausen, N. M., Jørgensen, O. H., Høffner, R., Andersen, P. E. B., Svensson, R. B., Hansen, P., Nybing, J. D., Magnusson, S. P., & Kjær, M. (2021). No Additive Clinical or Physiological Effects of Short-term Anti-inflammatory Treatment to Physical Rehabilitation in the Early Phase of Human Achilles Tendinopathy: A Randomized Controlled Trial. The American journal of sports medicine, 49(7), 1711–1720. https://doi.org/10.1177/0363546521991903
• Murphy, M., Travers, M., Gibson, W., Chivers, P., Debenham, J., Docking, S., & Rio, E. (2018). Rate of Improvement of Pain and Function in Mid-Portion Achilles Tendinopathy with Loading Protocols: A Systematic Review and Longitudinal Meta-Analysis. Sports medicine (Auckland, N.Z.), 48(8), 1875–1891. https://doi.org/10.1007/s40279-018-0932-2 

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Transcript

SPEAKER_00 0:07

Hello and welcome to Candid Conversations with Dr. Kelsey. I'm your host, Dr. Kelsey, and this is the space where I share my honest thoughts, real experiences, and the no BS conversations I wish more people were having about movement, training, injury recovery, and life as an active human. The goal of this podcast is to help you better understand your body, think more critically about rehab and fitness, and feel more confident making decisions so you can stay active long term. Before we start, a quick reminder. I am a physical therapist, but I am not your physical therapist. Nothing here is medical advice. So if you're dealing with something specific, please reach out to your PT or schedule a session to work with me. Alright, now let's get into today's conversation. If you've ever been diagnosed with something like Achilles tendonitis, runners or jumpers knee, golfers or tennis elbow or biceps tendinitis, you likely had some sort of tendon issue, which we now refer to broadly as tendinopathy. The previous understanding of tendinopathy was that there was an acute or more early stage, which was called tendonitis, and a chronic or later stage called tendinosis. But now both fall under the broad category of tendinopathy, meaning basically that the tissue sorry, the issue is with the tendon. While I was preparing for this episode, I wanted to make sure that the evidence I'd been using to inform my professional opinion on tendinopathy was still up to date. And then I ended up going on uh a bit of a rabbit hole. Luckily, I realized this before I went down too far. But long story short, the overall framework I've been using still holds up, but there's still a lot more nuance than a lot of people realize. And this is definitely one of those topics I could talk about for hours. So for this episode, I'm mostly going to focus on Dr. Jill Cook's papers introducing the tendon pathology continuum from 2009. So the model that most um up-to-date rehab providers use, and her paper from 2016 revisiting this model and also adding some new evidence. So, based on her papers, I'll break down what tendinopathy is and how to actually improve it based on the updated model. So, first, what is tendinopathy? So, again, before it used to be called tendonitis, and so the reason why it was called tendinitis was because it was thought that um it was an inflammatory process that caused this issue. And a lot of the treatments around this focused on trying to decrease the inflammation, so a lot of it was like rest and NSAIDs and all of that other stuff. Um, however, with the new model proposed by Jill Cook in 2009, it was proposed that tendinopathy was actually the inability for the tendon to adapt to different loads. Um, and it applies to both ends of the spectrum. So if you overload it too much, your the tendon is not going to be able to adapt. And then so that's when you start um experiencing some of that pain or maybe um some structural changes, so aka damaging the tendon, um, and the tendon's not able to heal from that. On the opposite end, however, if you underload it, so if you like basically do nothing for a really long time, um you go into with uh what she proposed as stress shielding, and you're basically not letting the tendon adapt. So um this is really evident in like for those of us in our 30s and 40s who let's say want to go back to playing basketball, you haven't played basketball in the ball in years, and you go back, but you know, in the last what 10-20 years, you've been underloading that tendon, you haven't been playing basketball, and so you've been stress shielding that tendon, and now all of a sudden going back into basketball, the tendon uh was not able to keep its adaptations from when you were originally playing basketball in your like late teens and twenties, and so now it's not able to handle the loads that you're gonna put on it. Um, I guess this is not this is not the best um example because it goes a little bit into like overload and underload, but um the main point here is that both ends of the spectrum can lead to tendinopathy. So overloading or overuse and underloading. So not stressing it enough and allowing the tendon to maintain its robustness um can also lead to pathology. Um her so this was um from her paper in 2009. Um and again, like always, I'm gonna have the links in the show notes for her papers if you want to review them yourself. So in 2016, when she revisited this paper, um she so in the original paper, the proposition was that to improve tendinopathy, you needed to have structural changes. So basically, like what most people think is you need to heal the tendon itself. With the new paper, um and uh they considered the evidence that had come out since 2009, and they found that you know it's still kind of true that you that you can have structural changes to improve the tendon. However, sometimes structural changes were not related to pain. So sometimes, for example, if you uh did an MRI on someone's tendon, there were structural changes present. However, the person didn't have pain. However, even if they didn't have pain, they might still have some functional deficits. Um, an example of this is for people with degenerative uh tendon changes. So, and basically as we get older, um, again, if we're not using our tendon as much, it's just going to it doesn't need uh the body has sensed that it doesn't need to be used as much, so it doesn't maintain its robustness. Um, that's kind of what's um commonly seen as degenerative. And for those individuals, they you see the structural changes, however, a lot of times they don't have pain, but maybe you ask them to do a single leg calf raise and they're unable to do that. And so that's what I'm talking about when he says there are structural and functional changes, but no pain. And so now the updated goal from this 2016 paper is that instead of trying to only focus on the tendon structure, um, and instead of trying to figure out what stage that they're in based on the structure of their tendon and um uh choose treatments based on that, the new goal is to improve um any functional deficits. So in this example, improve their ability to do like a calf raise, which um is important for a few things, and also improve the tendon's load capacity, so its ability to um its ability's ability to uh uh tolerate load. So, again, for example, being able to do a calf raise, like lift the person up. Um, so how to resolve this? Um going back to the original model, the tendonitis model, that like the inflammatory model. The before, like uh like I've already mentioned, the standard was to arrest and maybe splint. Um, and that's unfortunately still kind of common today with some providers, especially if they haven't stayed up to date on the evidence. Um, I've seen this when I worked in the clinic where people would come in and they're like, Yeah, the either podiatrist or usually was a podiatrist. Um, I don't know, you know, I'm I'm not throwing shade. I just I think it just happened to be like at the practice that I was at. Um, but um they would be like, Yeah, I had I was diagnosed with like Achilles tendonitis and I was in this boot for three months, and now they told me to go to physical therapy. And so um that's the old model, and the reason why it doesn't work is because we're not trying to tamp down the inflammation. Um the inflammation that they see that you will see on imaging when it comes to tendinopathy is not always bad. Sometimes it's just kind of a symptom. And so decreasing the infl trying to decrease the inflammation, yeah, maybe it'll help with your pain, but it's gonna do nothing for the function. So and and these patients would find that out the hard way because they're like, okay, well, now I don't have pain day to day because maybe they got to a point where it was even painful at uh when they weren't doing much. So now they don't have pain, but as soon as they try to load the tendon up, um, like maybe return to running or something, um, then the pain comes back because now that tendon has been the tendon has been stress shielded, and so it's unaccustomed to like heavier loads now. Or it um and um and what I mean by the heavier loads is unaccustomed to like you asking more of it than just like walking around, basically. And so the focus on any uh tendon rehab is going to be improving the tendon's ability to handle load, as well as addressing the functional deficits around the tendon. So um in the case of like patellar tendinitis, for example, for example, patellar tendinopathy, um, a lot of times people's quads get super weak, and so uh the functional deficit here is going to be improving their quad strength so that they're not doing weird stuff, so to speak. Um anecdotally, so in my like from my experience, like I've experienced like quote unquote runner's knee fairly often, and a lot of time so I understand like a lot of times the knee gets like super painful, and so you end up kind of walking or running in like this weird way, and um this came out like super obvious to me when uh when I was returning to running after my pregnancy, and then um my left knee, for example, didn't have any pain, so when I had to do single leg hops on that side, I was doing them fine, but then I I noticed when I had to do single leg hops on my right side, um I was having knee pain, but I was also realizing that I was somehow trying to use too much of my knee instead of my foot. I don't know if that makes sense without um trying to show you, but um I basically wasn't loading properly on that right side, I think because my body was trying to protect my knee because it was painful. Um, but in doing so, it was probably loading it up a little bit more or loading up my hip. So anyway, that can also kind of go down like a really weird rabbit hole. But I was I was trying to give an example of uh functional deficits. So, with this current model, we want to be able to improve the tendon's load management and we want to be able to improve the tendon's force production um as well as um improve any functional deficit deficits that we see. And so this is gonna involve loading the tendon, and it's going to depend on the individual. So the three most common um the three components of tendon rehab is go are going to include isometrics, so I so that's basically um any exercise that's going to um have the muscle contract but not move the joint. So, like a common one for like the patellar tendon, for example, is gonna be like a wall sit. Um another component is uh concentric and eccentric exercises. So a concentric is when you're like, for example, doing a bicep curl, so the muscle is contracting and shortening, and eccentric is going to be like lowering the weight during a bicep curl. So the the weight going up is is a concentric uh is a concentric contraction of your biceps, and then lowering the weight down is eccentric because your bicep is still contracting, but now it's lengthening. Um the key here is that it's gonna be these the these exercises should be relatively pain-free. There are some studies showing that um if the I mean it was specifically looking at degenerative tendinopathy, but if you if you have some pain, as long as it like if it's below the five out of ten threshold is usually or five out of ten pain is usually the threshold for like okay, if it's if it's five or less, then it's quote unquote acceptable pain, versus if it's higher than that, then we might need to pull back a little bit and go back to isometrics. And then after this, so after the concentrics and eccentrics, depending on what you're trying to get back to, so if you're trying to get back to something like tennis or anything else that involves um some sort of impact like that, you and you have and you're treating like uh Achilles tendonitis or like or Achilles tendinopathy or patellar tendinopathy, something like in a lower limb, you want to also do plyometrics because that way you're continuing to load the tendon and have it adapt to these um to these greater loads. Because if you just stop at like something, um if you stop before plyometrics and then let someone go and continue to uh return to tennis or whatever without any restrictions, they like you're not adequately preparing the tendon, and so it's probably gonna come back more quickly. Um, the tendon issue. Um, so those are the three components of tendon rehab. Uh, the order in which you do them with, or sometimes people will skip isometrics, it just really depends on the person, how much pain they're in, how long they've been dealing with this pain, as well as any other functional deficits that they have. So this brings me to the tissue timeline healing. So, on average, the amount of time it takes for someone to get better from like a tendon issue is gonna be three to six months. And obviously, the longer you've been dealing with this issue, the longer it's gonna take to get better. Um, if you've only been dealing with the issue for a couple weeks, it's probably gonna get better faster. And the like some but but generally people take three to six months to get better. Um, like three months is usually kind of like like the first three months um is when people are like, Oh, I don't know, I don't see any changes, and then usually they'll kind of see a turnaround at like the three-month mark. Um in my personal or not my personal opinion, but in my professional experience as well as in the literature, like three months is usually kind of like the minimum. Um, and six months is kind of usually the upper end of that. But for some people, it does take longer than that. It can take up to a year or longer to really get better um or back to 100%. And it's one of those things where you're definitely gonna be on a roller coaster. There's gonna be weeks where it's like everything seems to be doing well, and then there'll be weeks where you might have a little setback or something. Um, because tendons take a really, really long time to heal in general, and when it comes to pain, there's so many contributors to pain as well. It's not as simple as trying to, you know, do this one exercise and improve that pain. So, um, so yeah, it's one of those things where if you start to feel something and it's not going away after a few weeks, then definitely get help earlier. Because if you wait, for example, you've been dealing with like some tendon thing for a couple months, and then now all of a sudden you realize like your race is in a month, like not a lot is gonna get better in a month. However, with that, um, I also want to talk about the role of like injections and other therapies because I know a lot of times people are like, oh yeah, I had like biceps tinnitis and I got an injection and I felt so much better, and so I stopped going to physical therapy. Or same thing with shockwave. Like these things are amazing for pain. I will say I myself have used shockwave for uh my Achilles pain, like the week before my Hyrux race, um, because I it was starting to act up again. But these are short-term fixes, these are not going to cause like longer-term adaptations to the tissues. So um in these instances, like, yes, if you need the injection in order to tolerate rehab, or if you have like something coming up and um if you have something coming up and you you need to decrease the pain relatively quickly, like I mean these um these things have their place, like injections and shockwave therapy and dry needling, all of those things have its place, but they're not to be used alone. Like at the end of the day, you need to be able, you need to load the tendon to have it adapt or to have it go through those adaptations if you don't want to deal with this constantly. Um, because these injections and shockwave, like it only lasts for a certain amount of time, and so you're you're just gonna have to keep repeating this. And I mean, I guess some people would rather do that instead of actually addressing like their actual issue. Um, because obviously it's easier to just go to something somewhere and like have them do something to you, and then you don't have to do anything yourself, it doesn't require any work. But especially in the case of like steroid injections, like um steroid injections actually have can have kind of like the opposite effect. Well, not the opposite effect, I can't think of the word right now, but while it does improve pain, it eventually, if you keep getting steroid injection, corticosteroid injections, eventually it does wear away at the tendon. And so then you get um then you have a higher risk of rupturing the tendon. And that is uh that is a very, very difficult rehab in itself as well. So if you're thinking about you have a tendonopathy, and that already takes a long time, getting a tendon repair or healing and recovering from a tendon rupture and subsequent surgery also takes a really, really long time as well. So that is something to keep in mind where yeah, these quick fixes are adjusting the pain, but it's not adjusting the underlying issue itself. Um and whether that's maybe you've been overtraining or your nutrition and recovery is not up to par, or just the fact that um maybe you just need to improve the tendon itself. Um, like all of those things need to be addressed in order to improve the health of your tendon. So, in summary, the new model for tendinopathy is basically your tendon's inability to adapt to loads put on them, and whether that's you overloading the tendon or you underloading underloading the tendon and causing it to go into like a stress shielding response. And so, especially with updated evidence, the new goal for treating tendon issues is going to be well, yeah, you want to improve the tendon structure, but the number one goal is going to be improving your functional deficits and the tendon's ability to tolerate load. And so to do that, you're going to be focusing on isometrics, um, relatively pain-free, concentrics, and eccentric exercises, and uh progressing to plometrics, um, especially if you're going to be going back to something that requires a lot of impact. And the when thinking about rehab, you want to remember that this takes at least three to six months to get better. And the earlier you start rehab, the earlier that or the faster that you're gonna get better, versus the longer you wait, the longer it's gonna take to get better. Um, and injections and you know, other adjunct therapies like shockwave, they have their place. Um, they can definitely be helpful, but it's not something That you're gonna do uh instead of exercise. You're still gonna need the actual exercise and loading part in order to actually get better. And these adjunct therapies are there mostly to decrease the pain so that you can tolerate loading up the tendon and um having it go through those adaptive changes. So hope you found this helpful. Um, if you want me to go a little bit deeper into this topic, definitely send me an email at info at an eaterpcp.com. It's also linked in the show notes. Um and let me know. Otherwise, thank you for listening and I'll see you in the next conversation.