Tendinopathy: 6 Things You Need to Know
Written by Mitchell Robinson
Tendinopathy (also known as tendonitis and/or tenosynovitis) is a tendon disorder that can develop in any tendon in the body and results in pain and impaired function. This is a deep dive into the 6 things you need to know! For the short abridged version, click here.
WARNING: While I've done my best to make this series interesting, it's slightly more information dense than some of our other posts - but persevere! Knowledge is power and the reward for your hard work is manifold! Of course, you could always book in with of our physios here and let us do the hard work for you if you prefer!
1. Tendinopathy has three different stages:
i) reactive tendinopathy,
ii) tendon disrepair, and
iii) degenerative tendinopathy.
It’s best to think of these stages as a continuum rather than three distinct phases (see figure below).
a. Reactive tendinopathy "is a short-term adaptation to overload that thickens the tendon, reduces stress and increases stiffness. The tendon has the potential to revert to normal if the overload is sufficiently reduced or if there is sufficient time between loading sessions" (Cook and Purdam, 2009). Expert physiotherapist, Tom Goom, writes, "[we] thought this reaction involved inflammation but we now understand this is not the case. The tendon does swell but this is due to movement of water into the tendon matrix and not inflammatory products. A key feature of a reactive tendon is that structurally it remains intact and there is minimal change in collagen integrity."
Histopathological appearance of reactive tendinopathy/early tendon dysrepair. Note the increased cell numbers and intermittent cell rounding with some evidence of increased ground substance (light blue shading)
Histopathological appearance of late tendon dysrepair/degeneration. Note the markedly increased cell numbers, the loss of collagen evidenced by the loss of longitudinal rows of cells, and the increase in vessels.
Tendon dysrepair "describes the attempt at tendon healing, similar to reactive tendinopathy but with greater matrix breakdown. [...] There may be an increase in vascularity and associated neuronal ingrowth. [...] Some reversibility of the pathology is still possible with load management and exercise to stimulate matrix structure." (Cook and Purdam, 2009)
Again, it's important to note that attempts at staging tendinopathy include modest degrees of subjectivity. As we're dealing with a continuum, no objective "lines" exist whereby one can positively assert that someone has progressed/ regressed from one stage to another.
c. Degenerative tendinopathy involves "areas of cell death due to apoptosis [planned cell death], trauma or tenocyte [tendon cell] exhaustion [...] As a result, areas of acellularity have been described, and large areas of the matrix are disordered and filled with vessels, matrix breakdown products and little collagen [boo!]. There is little capacity for reversibility of pathological changes at this stage.
An analogy might be when you piss off the missus - if you apologise quickly and admit you're a moron, all may be forgiven (reactive tendinopathy)! But if you persist in your stupidity (keep overloading the tendon), the relationship may not heal and you could be kicked out for good (degenerative tendinopathy)!
Pathology continuum; this model embraces the transition from normal through to degenerative tendinopathy and highlights the potential for reversibility early in the continuum. Reversibility of pathology is unlikely in the degenerative stage.
Cook and Purdam (2009) simplify the diagnosis, writing,
An older person with a thick nodular tendon is likely to have a degenerative tendon; conversely a young athlete after acute overload with fusiform [tapering at both ends; spindle-shaped] swelling of the tendon is likely to have a reactive tendinopathy.
2. Management of tendinopathy depends on its stage:
i) reactive/early dysrepair and
ii) late dysrepair/degenerative.
Management varies considerably between these two stages so getting assessed by a physio is very important. Goom writes, "Many runners will have heard of “eccentric” exercise for tendon problems and may be trying ‘heel drops’ for Achilles tendinopathy or other eccentric exercises. This will probably make things worse in a reactive tendinopathy but might help in the degenerative stage – this is why staging is so important! If you don’t identify the correct stage you could well be making your problem worse!"
To continue the analogy, if you think your wife is mad because you continually leave your beard trimmings in the sink when in actual fact you forgot your wedding anniversary (and you continually leave your beard trimmings in the sink), she gon' be mad! And your problem may be made worse if you think some $15 flowers from Woolies will suffice!
The 'donut analogy' for tendinopathy: the unhealthy part of tendon is the hole and the healthy tendon is the yummy donut bit. If you don't rehab the tendon appropriately the disruption can worsen (i.e., make the donut hole bigger). If you do rehab the tendon appropriately, it's suggested that the healthy tendon that's left increases capacity to tolerate the load which may mean less pain.
3. Tendinopathy does not improve with complete rest
Rest is one fo the most important variables in managing tendinopathies. We often hear that because some activity is painful it should be completely avoided. This is not helpful. Completely offloading the tendon (e.g., bed rest, couch time/Netflix, hopping around on crutches, etc.) may settle the pain, but returning to activity is often painful again because rest does nothing to increase the capacity of the tendon to load. Tendons will adapt to load if given appropriate rest. Sometimes a tendon may be able to be loaded more than once in the same day. Sometimes a tendon will need a few days to recover - it depends on the individual and on the exercise/s chosen.
For those of you who enjoy running almost every day, some sensible options to manage pain include rest days after longer or more intense sessions, performing some other mode of exercise instead (this is called 'cross-training'), or opting for some slow 'recovery' runs.
4. Managing reactive/early dysrepair tendinopathy
The most important concept in this stage is load management; both tensile (tension along the tendon) and compressive (compression across the tendon) loads must be considered. Tensile and compressive loads can occur at any tendon in the body.
An example of tensile load -> tension along the achilles tendon that occurs with running.
An example of compressive load -> compression across the hamstring tendon at the ischial tuberosity (bone you sit on). Compression here can occur with hamstring stretching/hip flexion (lifting the knee up).
Each time your foot contacts the ground during running your body has to deal with an impact force equal to roughly 2.5x your body weight. Fortunately tendons are thought to be able to withstand up to approximately 8x body weight.
An example of three ways to reduce the tensile load through the achilles tendon include:
- decreasing how far we run,
- decreasing how fast we run, and
- taking a short break from running.
An example of compressive load can be seen with proximal hamstring tendinopathy (right image above). In this condition, the tendon is thought to be compressed against the ischial tuberosity when the hip is flexed; and even more compression occurs with sitting. Reducing time spent sitting is a simple way to reduce this compressive load. And, obviously, combining compressive and tensile loads is even more provocative. Consider lunging, running uphill, or stretching the hamstring muscles; in these examples both tensile load and compressive loads are occurring - ouch!
Cook and Purdam (2012) have created the following table summarising common compression sites and potential modifications that could be made:
The reactive stage often settles relatively quickly - provided you don't continually piss it off! Prof Jill Cook (Aussie tendon guru and researcher) says pain may settle in 5 to 10 days - but the tendon will still be sensitive to high loads and training needs to be progressed gradually to stop further deterioration.
Be guided by how the tendon responds NOT just immediately following exercise, but also 24-48hrs after! Tendons are known to have a latent response to loading; they can take 24hrs or more to react to what you've done. Bare this in mind when running – it may feel fine at the time but react the next day!
Isometric exercise is where the muscle works against resistance without creating joint movement or changing muscle length. Isometrics work the muscle without movement. Specific isometric exercises are recommended depending on the area of the tendinopathy. I recommend asking your physio to show you specific exercises pertinent to your case.
Isometrics are often a great option for reactive tendinopathy for a few reasons:
1) they may reduce pain in the short term,
2) they can maintain muscle/tendon/bone health and strength,
and 3) they foster independence (rather than dependency) regarding pain management.
A very bored looking gentleman performing an example of isometric hip adduction.
There has been some (justified) pushback from researchers towards those who have hailed isometrics as the panacea for reactive tendinopathy. While isometrics are a good option for management, it's nevertheless important to consider that they:
- provide quite varied responses from individuals regarding pain relief and functional improvements,
- often show no significant difference to isotonic exercises (where the joint moves through range of motion),
- should (almost certainly) take a back seat to more important issues pertaining to progressive load management and kinesiophobia (fear of movement)
(Clifford et al 2019, Coomes et al 2016, Holden et al 2019, , O'Neill et al 2019, Pearson et al 2018, Riel et al 2019, van Ark et al 2016)
Mitch's simple opinion on isometrics:
- They are not magic, they are merely a loading option. If you've seen me in clinic, you'll know I often say we are cooking not baking - that is to say there is some freedom regarding exercise prescription; you need not follow a rigid recipe.
- Consider isometrics as a good loading option among other good loading options (including isotonics, eccentrics etc). What contraction type can you perform without breaking pain rules?
- Isometrics can be progressed in much the same ways as any other loaded exercise (weight/resistance used [can be objectively measured or simply by using RPE], time under tension, range of motion utilised, rest periods, rate of force development [rapidly vs slowly increasing tension], total volume of loading (sets x reps x resistance) etc.)
- All things being equal, incorporating a variety of contraction types in rehab seems appropriate when attempting to build comprehansive capacity (whatever that means :p)
Don't perform isometric exercise in a position where the tendon is compressed - duh!
Exercise or rest?
Choosing to exercise or rest is can sometimes be a complex decision as a number of different factors can come into play.
- Are you training for some event or just training in your off-season?
- How severe and irritable are the symptoms?
- Can you find a way to exercise without pain?
- Both at the time and 24-48 hours later?
- How is your body generally?
- Are you struggling with a host of niggles that need some rest?
- What is the bigger picture here?
- Will timely rest now stop this from becoming a chronic, long term issue?
This tip is a little bit controversial. However, I think as a general rule, it's sensible to avoid stretching reactive tendinopathies as this often annoys them! Occasionally, your muscles can feel tight - if this is you, still don't stretch! Instead, try a foam roller or massage ball. However I would work the main bulk/belly of the muscle and avoid pressure over the tendon area. For more information on stretching, click here and here.
As we've seen, load management is the most important concept in managing a tendinopathy. It's a balancing act though. Do too much and you'll piss it off, do too little and there's no stimulus for positive adaptation. Finding the balance is a little bit of trial and error. But the take-away is that complete rest is crappy advice; you should find some tolerable amount of exercise and progress slowly from there. If I'm dealing with a runner, a good place to start is pain-free walking, then progress to brisk walking, then jogging on the spot, then running. The best guide though is to see a qualified health professional and take their advice.
Moreover, starting with short distances or commencing with a walk-run pattern seems sensible. The temptation to increase the distance and/or pace may be there if the pain is negligible - however you must resist this urge! Observe how it responds over the next 24-48hrs and slowly progress if there are no flare-ups. Anecdotally, some patients report feeling worse when running first thing in the morning so make sure you experiment with the time you choose to exercise.
If your tendon is really pissed off and you're desperate to train or worried about losing some fitness, cross-training is usually a good option. Simply choose exercises with little tensile or compressive load - think, swimming, cycling, some resistance training, cross-trainer etc.
5. Managing late dysrepair/degenerative tendinopathy
Degenerative tendinopathy only really occurs in older people, or in chronically overloaded tendons (such as athletes, those with physically demanding and repetitive jobs, avid gym-goers etc.). To complicate matters, someone can have a single tendon that has both reactive parts and degenerative parts. In this case, the same tendon will exhibit symptoms of both phases of tendinopathy. The degenerative parts of the tendon (which are now permanently present) can exist alongside “normal” tendon that can temporarily become reactive with too much load. This means that, along with your old grumbling (degenerative) tendon, you can have a spike in pain with a spike in activity volume or intensity due to this emergence of a reactive portion of your tendon.
Image showing the relationship between reactive and degenerative tendinopathy in the same tendon.
So, how do you deal with these complexities?
Well, you first need to adhere to the above principles for managing your reactive tendon. You must put out the fire and address the reactive tendinopathy and then work on managing the symptoms of the degenerative tendinopathy.
To manage the old, grumbling, degenerative tendinopathy, you must
- Manage your load
- Incorporate loaded work within pain limits (eccentrics, isometrics etc.)
Examples of concentric, eccentric and isometric muscle contractions. These contractions can occur in any muscle in the body.
What is load management?
First, identify what loads you can tolerate and what loads piss it off. Tom Goom, a physio and tendinopathy guru, says there are two parts to this process: theory and practice. It’s important to know the theory and then see what happens in practice. That is to say, there is an element of trial and error involved as you learn how your body responds (as this may differ from the theory!).
For example, when dealing with a proximal hamstring tendinopathy theory states you should avoid compression of the tendon (sitting on it, stretching it etc.), temporarily avoid really heavy loading (lifting heavy weights etc.) and ballistic loading (running, jumping, etc.).
The location of the proximal hamstring tendon on the back of someone's right leg.
An example of a nordic hamstring curl. You have to be a strong SOB to perform the concentric portion of this exercise!
Hill sprints are possibly the most provocative thing here as elements of both compression and high ballistic loading are combined. However, in practice, you may notice that what actually aggravates your tendinopathy does not fit the theory. And that’s totally OK! A training diary here may be appropriate so you can more accurately monitor what your putting your tendon through and make changes as needed.
Now, you obviously shouldn't avoid sprinting and running up hills forever! So, slowly incorporating hills and speed work over time seem sensible. Gradually reintroducing previously aggravating factors allow the tendon time to adapt and accomodate the new loads. It’s commonly said that you should make one change at a time (e.g., volume or intensity, not both!) and change things slowly.
When incorporating eccentric training, there are a myriad of variables that mean this will look different for everyone - no recipe I’m sorry! Some may tolerate 6s eccentrics, larger ROM used, and very heavy loads. Others may find this provocative. Remember, we are “cooking, not baking” - this is not a recipe approach!
Appropriate investigation (blood work, imaging etc.) should be considered to screen for red flags at the start of treatment or after a period (~3 months) of conservative management with no change in symptoms or function. Surgery should only be considered after a year (at least) of conservative management. Your doctor will probably recommend a CSI or PRP injection but know that these interventions have mixed evidence. Steroid injections in particular have been shown to delay healing, increase chance of rupture and have poorer long-term outcomes (Bisset et al., 2006).
Tom Goom has provided a potential rehab progression handout for a helpful summary:
If you're confused about all this stuff, book in! We tendon nerds would love to help you become pain-free!
Bisset L, Beller E, Jull G, Brooks P, Darnell R, Vicenzino B. Mobilisation with movement and exercise, corticosteroid injection, or wait and see for tennis elbow: randomised trial. BMJ 2006;333(7575):939.
Cook JL, Purdam CR. Is tendon pathology a continuum? A pathology model to explain the clinical presentation of load-induced tendinopathy, British Journal of Sports Medicine 2009;43:409-416.