You may have come across the terms TENDINOPATHY, TENDINOSIS or TENDINITIS in the past. Maybe you were diagnosed with one or you have heard friends and family being diagnosed. Or you have patients or clients who have come to you with these issues. But what exactly do these terms mean? And what can we do about them?
Well after listening to Jill Cook talk on Physiopedia and then continuing to do a little more research, I've managed to put some information together to help us to understand these conditions in more detail.
SO WHAT EXACTLY IS A TENDINOPATHY ANYWAY?
Well by definition it is “Pain and dysfunction in the tendon”. However this is a term that is often used incorrectly most of the time. This term is actually a clinical diagnosis ("The estimated identification of the disease underlying a patient's complaints based merely on signs, symptoms and medical history of the patient) because we cannot get into the tissue to see if there is degeneration in the tendon to get pathological term (which is based on a laboratory examination or medical imaging). Hence why we go for the clinical term that does not rely on knowing what is actually happening in the tendon but rather how it affects the patient.
Therefore, put simply, Tendinopathy is an umbrella term for someone that presents with pain and dysfunction in the tendon. And this is perfect, because according to research, understanding what is happening within the tendon is actually not that important after all.
What I mean by this is that there are quite a few studies that show that structure does not change very much with treatment but patients actually lose their pain and become much more functional.
This is important to remember which is why I want to say it again…
Patients become more functional and in less pain despite nothing major happening to the structure of the tendon. Therefore again, structure is not that important but it's how the patient feels and can perform, that is important.
SO WHAT IS THE DIFFERENCE IN TERMS OF THE NAMES THAT WE COME ACROSS?
Well, TENDINITIS implies inflammation (-itis means inflammation). However research states that there is very rarely inflammation apart from in the acute stage.
TENDINOSIS means degeneration in a tendon (the state or process of decline or deterioration).
However, according to the Cook and Purdam Model (2009) there are stages that a tendon goes through before becoming a degenerative tendon. This means that Tendinosis usually reflects that end stage disease where the collagen is disrupted.
IS THERE ONLY ONE MODEL TO DESCRIBE TENDON PATHOLOGY?
No this is not the only model out there. I think there are roughly 7 other models of tendon pathology about. But I like the Cook and Purdam model. It just makes sense to me.
LET'S EXPLAIN A LITTLE MORE ABOUT TENDON PATHOLOGY….
Now it's important to note that Tendon pathology is not a single disease. It is not JUST about degenerative tendons. As the model states, there are stages that the tendon goes through before ending at that degeneration. And it's actually these other stages that we come across more often.
So firstly there is REACTIVE TENDINOPATHY. This is actually a cell based response where by Proteoglycans (specialized protein molecules that are found around cells and in the joints of our bodies) disrupt the matrix (which is a collection of molecules that are secreted by cells that provides structural and biochemical support to the surrounding cells)
SO IS REACTIVE TENDINOPATHY A PATHOLOGICAL CONDITION?
Yes this is pathological because there is enough matrix change and cell change to actually cause pain. There is also enough change that we can see it on an image, you can actually see the changes in the tendon. But the good news is that it is reversible. So any changes are not absolute to the tendon.
WHAT SETS OFF THE REACTIVE STAGE IN A TENDON?
Load. Or more accurately, OVERLOAD. There is no doubt that nearly every tendon presentation to a clinician or therapist will be traced back to an overload of some description. Therefore if you unload the tendon then it can reverse in the reactive stage.
SO DOES THE TENDON GO THROUGH ANYTHING ELSE BEFORE BECOMING REACTIVE?
Actually there is some research that shows earlier stages than reactive tendinopathy where we see transient change in tendons (meaning that it lasts only for a short time and is impermanent). And again knowing that tendons respond to load, if we unload them at this first stage then we can sometimes recover within hours to days. This stage isn't reactive it is simply an adaptive part of a load response in tendons. Which means that this Transient stage is NOT pathological but a reactive tendinopathy IS pathological.
SO WHAT HAPPENS IF WE DO NOT UNLOAD THE TENDON?
If we do not unload the tendon, if we strap it up, take ibuprofen and continue to do whatever it is that is causing the problem in the first place then the condition continues to progress which means the cell and the proteoglycans will continue to disrupt the matrix. The more disrupted the more the stages are progressed. Therefore the level of matrix disruption will determine whether it is in the REACTIVE stage, DYSREPAIR stage (dys- meaning abnormal, bad or ill) or a DEGENERATIVE stage. The more matrix disruption the more it moves from Reactive to Dysrepair to Degeneration.
WHAT HAPPENS IN THE DEGENERATIVE STAGE ?
The Degenerative stage is where there is a substantial disruption of the matrix. And chances are that it has been there for months to years. Sometimes many years. (Although occasionally they do develop in less than a year). However there is not much research on how long it takes for a tendon to become that disorganised.
So in the Degenerative stage the matrix is disorganised, the collagen is no longer parallel, there are different types of collagen in the tendon and it becomes 'mechanically deaf'. Which means that we cannot load collagen that has no structure as it is not load sensitive. And once the tendon enters this stage it's pretty difficult (if not impossible) to reverse that change once it has occurred. But please don't panic because this is not something we need to worry about. Recent research by Sean Docking's show that this is something we adapt to (but that’s for another post!)
The one think to note is that if we have a truly degenerative tendon then chances are we're actually not going to have many problems simply because they tend not to be painful. Again the Degenerative area is mechanically silent or 'deaf' and so does no longer respond to load and so do not get pain the same.
WHAT CAUSES THE PAIN?
Now when it comes to pain, as we have discussed so many times on this page, the cause really is the great unknown!!
However one thing that we can tell from limited research is that pain in a tendinopathy is probably due to substances produced by the cells that are activated by the overload. So as the tendon becomes overloaded the cells respond to this overload by producing substances. These substances then stimulate the nerves that drive the nociception ( which is the sensory nervous system's response to certain harmful or potentially harmful stimuli).
But as we already know, pain is a super complex subject so there will be so many other factors involved too.
SO BACK TO DEGENERATIVE TENDONS…
In degenerative tendons the normal part of the tendon that IS tolerating the load is doing very well (you will have 'normal' parts even if you have a degenerative tendon). So people with degenerative tendons will often have lumpy bumpy tendons and may have had a bit of pain occasionally, but they don’t present as pure degenerative tendons because there is no reason for them to come in as they are not painful.
BUT WHAT IF THE 'NORMAL' PART OF THE TENDON DOES BECOME PAINFUL?
Well this is what is referred to as a REACTIVE ON DEGENERATIVE. This is where a degenerative tendon is overloaded and the normal part of the tendon that is left actually becomes reactive.
Therefore we know that the degenerative area is what is described as 'mechanically deaf' meaning that it does not change its structure very much, but that we DO get a reaction in the normal part of the tendon (which is why discussing the reactive stage is so important).
Now you should be able to understand that is why we're only going to have problems with Reactive tendons and the Reactive on Degenerative. We won't have much trouble with just Degenerative Tendons.
HOW LONG DO THESE TAKE TO SETTLE?
So on one end of the spectrum, a true reactive tendon will mean that a patient may come in with extreme pain. These tend to be younger athletes who have had an abusive overload causing the tendons to become really swollen and sore. These settle much more slowly than Reactive on Degenerative tendons and can take somewhere between 4-8 weeks to really ease up.
And on the other end of the spectrum you have reactive on degenerative tendons which tend to happen in older people (Although yes they can happen in young as you can actually have Degenerative tendons at a very young age but generally tends to be someone who has had a lot of load on their tendon over the years). The overload that they have done is not as dramatic as our Reactive tendons (usually) and they tend to have had a history of tendinopathy. These settle much more quickly than Reactive tendons and will really become a lot less painful in somewhere between 5 and 10 days.
Therefore if the patient has rested for a week and comes back feeling better then you know that is a Reactive on Degenerative tendon simply because a reactive tendon won't settle that quickly.
SO WHAT SHOULD WE DO IF SOMEONE HAS A TENDINOPATHY?
Well in a true Reactive Tendinopathy, again because they are (usually) young and because it’s a new injury, we can recover it but we need to unload them from whatever caused the problem in the first place.
But one of the critical things about treating tendons is never to rest them completely. That being said it's also important to maintain a load that is not going to irritate the tendon. This is why Isometrics (Muscle energy techniques that I share a lot on my page) are brilliant. All of a sudden we have an exercise tool that we can use in the painful tendons, that work well with the tendons. It means that we can therefore look to settle pain with an isometric load and still continue to keep SOME load on the tendon.
We also need to make sure that they are taken off the high level energy storage loads that usually create the problem (running/ sprinting/ box jumps/ double unders/ etc) and monitor how many times a week they are active. Simply put, we need to really make sure that we pull the load down just under the capacity of the tendon (without the tendon flaring up!).
In our Reactive on Degenerative ones, they will settle relatively quickly so you don’t have to do very much to settle them. Again as above, reduce the load (probably for a few days). But what you do have to do after that is then improve the capacity of the tendons (make them stronger) so that simple overloads don’t keep stirring them up. So to stop this happening again we need to build the capacity in the tendon so that any load that we do is under their capacity. So it's about maintaining the balance between what the tendon is capable of tolerating and the load that we put on it.
WHAT ABOUT ECCENTRICS?
Now eccentric exercises (focusing on the lowering phase of a move) have been all the rage for years when dealing with Tendinopathies. But where do eccentrics come in these days?
Actually it seems that it depends who you ask. But if did maybe ask Jill Cook, who is one of the leading experts to pay attention to when it comes to Tendinopathies, she believes that eccentrics come "nowhere in isolation".
She also states that we should use isometric exercises (where there is no movement during contraction) for pain relief and to release cortical inhibition. Then we use isotonics which have an eccentric component to it, then use fast exercises which is more towards energy storage (which is probably a faster eccentric load). Then she suggests moving on to energy storage and release loads (which are the loads that really affect tendons negatively). But we should never isolate eccentrics anywhere along the treatment spectrum.
The important thing is that if we are aiming to return capacity to the tendon then basically, Eccentrics alone just won't do it. After all, we can't expect to be able to sprint if all we have trained to do is slow eccentric exercises. Otherwise we're asking a muscle and tendon to tolerate sprinting after we give it slow steady exercises. Let’s face it….it just won't do it (and it doesn't make sense). We actually have to train it to do the loads and to tolerate the loads that we want to put on it. After all, I can't think of too many sports or activities that use JUST eccentrics, can you?
SO WHAT PROGRAMME DO WE NEED TO FOLLOW?
Unfortunately, there is not a recipe programme because every person with a Tendinopathy is going to be different. We can't treat an old lady with Achilles soreness the same way we treat a young athlete with Achilles tendinopathy. Again we simply cannot have one go to programme.
We need to give exercises specific to an individual person and the demands that they place upon their tendon. This is where we want to end up. But we’ve got to progressively increase the load from what the person is able to tolerate, what the tendon is able to tolerate when we first see them and gradually increase the load up to what the person needs to be able to tolerate when they are returned to their chosen sport or activity.
So that’s what we need to find out. What can the person currently do? And what do they need to be able to do? Then we'll go from A to B over a period of weeks to months. Of course that progression will be different for every single person because everyone is different, which is why we need to be taking into account personal circumstances, presentation and risk factors.
But please note that this is all about building up the capacity of the tendon GRADUALLY. It's also where the Acute:Chronic Workload Ratio created by Tim Gabbett comes in perfectly to allow us to do this with less risk of injury. But again that's another post.
WHAT ABOUT IMAGING? ULTRASOUND? MRI?
Again according to Jill Cook, so many of us are far too dependent on pictures. And as already discussed above, structure doesn’t make a big difference in how we should be treating Tendinopathies especially with those people in the degenerative spectrum.
So even if someone presents with horrible looking Tendinopathy on their ultrasound or MRI, the treatment shouldn't really change that much. It's more important to assess the patient well, working out what they want and then developing an individualised programme to reflect their goals.
HOW SHOULD WE TEST OR ASSESS A PATIENT?
This one is simple. We need to assess their function, particularly their high end function. Their tendons will be strained by energy storage and release loads so we need to look at how good they are at that.
All of this is so critical to assessing and then managing a tendinopathy. As discussed above there is not much point in looking at the pictures and there is no point in poking the tendon as neither of those can give us anything that we can actually work off.
We actually have to work out what the capacity of the tendon is, how the muscle tendon unit and the kinetic chain are doing and then work on that to restore function.
We are looking for the relationship between increasing the load on the tendon and pain. Therefore we will increase the load on the tendon to a point where we don’t want to do it anymore because we have had quite substantial pain from it and THIS then gives us a good understanding of what the base ability of the tendon is.
So for some people it may be a double leg heal raise for a tendinopathy on a person who hasn’t done much loading and has a tendon pain going up on to their toes with two feet. If that's the case then we're not going to assess much more than that. But we may get someone else who eventually gets to hopping and change of direction stuff to elicit that pain and to elicit that level of function.
Basically what this means is that even assessing the function of the tendon is highly individualised.
WHERE DO BIOMECHANICS COME INTO THIS?
Although there is very little evidence that biomechanics are much of a player in the ONSET of tendinopathy, there are a couple of tendons where biomechanics are much more important. Glute medius tendinopathy can be linked to biomechanics as can tibialis posterior in older people where the foot posture is really critically important.
That being said, on the whole, a person's Biomechanics may change BECAUSE of tendinopathy causing their function to change rather than their biomechanics causing the tendinopathy (but of course there are exceptions).
But whatever the reason, we will have to restore those biomechanical changes at the same time as dealing with the tendinopathy issues. They should not be treated exclusively. One CAN influence the other and so we might as well address them together.
With all this being said, it is important to focus on the individual. We are looking at bringing them back to their individual 'normal' function that they require, which means it will be individualised (as always).
When it comes to Tendinopathies it's important to not get sucked in to simplistic models of assessment or management recipes. We need to assess the person in front of us and treat them appropriately. We need to remember that everyone is different and that we should manage our patients to reflect that.
I also believe that education is key for patients (isn’t I always!). Educating them on the stages of Tendinopathy, how the body adapts to it (including the fact that degeneration is not a problem!), the causes of tendinopathy, how to load appropriately and how pain and function is not related to pathology. The more we know the more equipped we are at sorting these issues out.