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What’s the difference between Achilles tendonitis, tendinosis, tendinopathy and tendinitis?


Nothing. It basically boils down to a disagreement among researchers. Medical names that end in “itis” are used when something is inflamed. It used to be thought that Achilles pain was caused by inflammation in the tendon and it was therefore called Achilles tendonitis or tendinitis.

But more recent research has shown that inflammation is rarely present in ongoing tendon pain and researchers therefore feel that we should rather call it Achilles tendinosis or tendinopathy.

Don’t let all of this confuse you – the name really doesn’t matter! We’ll mostly be using Achilles tendinosis and tendinopathy but just know that it's exactly the same as Achilles tendonitis or tendinitis.


How your Achilles tendon functions


The Achilles tendon is the thickest tendon in your body and firmly attaches your calf muscles to your heel bone. It acts like a powerful spring that helps to propel you forward as you walk, run and jump.

The Achilles tendon acts like a spring that propels us forward when running.

The Achilles tendon acts like a spring.

Nearly all the force you generate when pushing yourself forward goes through the Achilles tendon. This force can be as much as six times your bodyweight when running fast.

When the Achilles tendon is injured, it becomes more pliable and loses some of its spring-like properties. When you have Achilles tendinopathy/tendonitis you may sometimes notice what appears to be a thickened, slightly swollen bump in your tendon. This is due to the cells and collagen fibres that make up the tendon changing their shape in response to the injury.


How does your Achilles tendon get injured?

The main reason people develop Achilles tendon pain is due to overload. The term overload is pretty much self-explanatory. It means you work the tendon too hard, causing it to develop an injury.

You can overload your Achilles tendon suddenly by putting in an unusually hard training session or changing your training terrain (flat to hills) or volume or just walking much more than normal.


Overload can also happen gradually by not giving the tendon enough time to recover between hard training sessions. Examples include speed or track sessions, hill running or plyometric exercises.

Graph of what happens to your Achilles tendon when you exercise and why you may get injured when you don't allow enough recovery.


Switching shoes or running style can also cause trouble. Walking around in flip-flops or wearing flatter running shoes or switching to running more on the front of your feet will cause the Achilles to work harder than normal and may cause injury if you don’t introduce it slowly.

Other factors such as lower back injuries and how you use the muscles in other parts of the body may also play a role in you developing Achilles tendonitis/tendinopathy. One of the advantages of consulting us about your Achilles pain is that we take all of these factors into consideration and make sure that we identify all the factors that we need to address to get you back to your sport.


How do you know you’ve got Achilles tendonitis / tendinopathy?

Achilles tendons can develop pain either where the Achilles attaches to the heel bone (insertional Achilles tendinopathy) or higher up in the tendon (mid-portion Achilles tendinopathy).

Mid-portion Achilles tendinopathy is by far the most common type (75% of cases) and you may even feel a thickened bump or painful area in the middle of the Achilles tendon. Insertional Achilles tendinopathy is not as common (25% of cases) and causes painful swelling where the tendon attaches into the heel.

The first time people usually notice Achilles pain is towards the end of a training session (a walk, run, tennis session etc.) or a few hours after. If you’ve really overdone it, you may wake up with a very painful tendon that makes you hobble for most of the day. In most cases, however, the Achilles is stiff first thing in the morning but then warms up as the day goes on.

Initially, you may find that they can feel stiffness and discomfort at the beginning of a walk or run but that it disappears as you go on and the tendon warms up. However, the discomfort and pain may return worse than before a few hours later.

If you continue to push your training and don’t get your Achilles tendon the treatment it needs, you may get to a point where the pain stops you from doing your sport and even just walking around the house hurts.

Do I need a scan?

No, because it won’t tell you anything more than what you already know. Scans are useful to confirm the diagnosis but they don’t tell you how bad the injury is or how long your tendon will take to recover.

Researchers have investigated several ways to test for Achilles tendinopathy / tendonitis and the most efficient test that they’ve found so far is when the patient tells you that they have a "swollen" area in their Achilles tendon or that the tendon itself hurts when they press on it. So yes, it turns out that listening to where the patient tells you they feel the pain is the quickest way to diagnose Achilles tendinopathy! 

Pain does not equal damage

While we’re on the subject of pain – it’s important to understand that the amount of pain you feel in your tendon doesn’t tell you anything about the severity of the injury. Pain is the alarm system of the body and how painful an injury is mainly depends on how sensitive your alarm system is.

If you ignore your injury for a while and try to train through it, your nervous system becomes more and more sensitive and starts to shout louder because it feels that you’re not listening to it. The injury isn’t necessarily getting worse but the pain may reach a level that stops you from training and even hampers your daily activities. That’s why it’s not useful to ignore your injury.

Also, the longer you irritate your alarm system and push into pain, usually the longer it takes to calm down again. Another good reason to seek treatment and guidance early.

How long will my recovery take?

Before we discuss what treatment options are effective, we feel it’s important to manage your expectations. Sorry, but there is no quick fix for Achilles tendinopathy/tendonitis. Even when following the correct treatment regime you will usually only start seeing big changes in how your tendon feels after 6 weeks.

How long your recovery will take, depends on how long you've had your injury for and how robust your tendon is.


If you've only had your injury for a few weeks and/or you are able to easily do single leg heel raises with good form and no pain, then you'll likely be able to ease back into your sport within 12 weeks of starting our programme. 

If you've had your injury for a few months and/or your tendon is really painful and/or you struggle to do single leg heel raises, it means that your tendon lacks quite a bit of strength and it will likely take between 6 and 9 months to get it strong enough to do all the activities and sport that you would like to do.

We are strong advocates for using relative rest which means that we always try to keep patients as active as possible while they recover. Instead of cutting all training, we prefer to advise on how you can adjust your training volume, playing with the type of training and terrain you train on to allow your tendon pain to settle down.

That said, you can prolong your suffering if you don’t seek help early enough or if you follow the wrong treatment protocol. Exercises and advice should always be tailored to the individual and we discuss this in more detail below.


What treatment is best for Achilles tendon pain?

There’s no one-size-fits-all treatment for Achilles tendinopathy/tendonitis. The right combination of rest and exercise is usually the most important intervention, but even this has to be tailored to the individual.

We often see patients in our clinic who have tried Achilles exercises that they found on the internet or even provided by other clinicians, only to find that it either had no effect or actually made their symptoms worse.

Relative rest

Rest alone is not useful for getting tendons to recover. It may make the pain feel better for a while but it will not fix the injury or prevent it from coming back. In most cases you don’t need total rest to allow healing to take place.

We are big proponents of relative rest. This means that we only get you to cut out the really aggravating activities, or to adjust your training programme so that you can continue to train without making the injury worse.

Being injured and not able to exercise can make you feel rather low. Relative rest is great as it not only allows you to maintain your cardiovascular fitness but also helps to lift your mood. We’ve become experts over the years in helping our patients analyse their training programmes and creating plans that allow them back to all sort of activities including walkingrunning and racket sports as quickly as possible but without reinjuring themselves.

Exercises for Achilles tendinopathy/tendonitis

Strengthening exercises, specifically aimed at the Achilles tendon, is by far the most effective treatment for Achilles tendinopathy. BUT that does not mean that the same exercises will work for everyone.

A carefully graded execise programme is needed to improve your tendon's capacity to cope with the demans of your sport.

Our clinical experience (and the research) have shown that these exercises should be tailored to the individual. They should also be progressed over time by increasing the load or speed at which they’re done. Examples of exercises that may form part of your rehab programme, depending on the stage of your recovery, include isometric, isotonic or eccentric heel raises as well as plyometric exercises.

Where patients (and sometimes clinicians) go wrong is that they either jump in and do exercises that are too hard for their Achilles, causing it to flare up, or they stick to the same set of exercises for weeks and weeks, which has little or no effect.

It’s also important to strengthen other muscles in your legs and core. For example, the glutes are meant to help propel you forward. If they are weak, your calf and Achilles may have to work harder, which is not ideal for someone with an Achilles injury.

That’s why our first step towards fixing your Achilles tendinopathy includes a detailed battery of tests to help us identify all the areas of the body that you need to strengthen.

The rest of the body is also important

You know as well as we do that no two people are built the same. Take feet. They not only differ in how wide and long they are, but their arches are also different shapes. None of the bones and joints in your body will be exactly the same as the person next to you. We all have different walking, running, hopping etc. styles as well.

This is the reason why certain interventions such as orthotics or stability running shoes work really well for some people with Achilles tendinopathy while it has absolutely no effect on others. We make a point of assessing your basic biomechanics (how your body moves and the shape of your feet) during our assessment to ensure that we address these issues if needed. We don’t tend to mess with people’s trainers or orthotics unless we can see a clear reason to.

Relative rest


If your tendon has suddenly become painful, you may find some pain relief from using nonsteroidal anti-inflammatory medication (NSAIDS) like ibuprofen or naproxen, but we would urge you to only use it if absolutely needed. What the research is showing is that NSAIDS can have a detrimental effect on acute tendon injury recovery as well as collagen formation in response to exercise. So taking this type of medication may actually delay your recovery. It can also affect your stomach and interact with other medications so please check with your GP before taking any.

Exercise fails

What if exercise doesn’t work?

The combination of relative rest and strength training will help most runners recover from Achilles pain, but it doesn’t always work. If you’ve stuck to a sensible programme that has been progressively made more difficult over several months and not seen any improvement, it may be time to consider more aggressive treatment options. We've all worked closely with several other sports medicine consultants in the past and can advise you on the different treatment options available to you. These treatment options may include shockwave and different types of injections.

Surgery is sometimes used if nothing else is effective, but it should really be considered as a last resort.

We hope you found this overview of Achilles tendinopathy/tendonitis useful. If you think you’re suffering from it, why not email us to find out how we can help you?

Are you wondering how Online Physio can work?

Alison has written a blog post that explains exactly how our online consultations work.

How we can treat your Achille tendon injury with an online physio appointment.
online pysio


  1. Cook JLTen treatments to avoid in patients with lower limb tendon painBritish Journal of Sports Medicine 2018;52:882.

  2. Cook JL, Rio E, Purdam CR, et alRevisiting the continuum model of tendon pathology: what is its merit in clinical practice and research?British Journal of Sports Medicine 2016;50:1187-1191.

  3. Couppé, C., Svensson, R. B., Silbernagel, K. G., Langberg, H., & Magnusson, S. P. (2015). Eccentric or concentric exercises for the treatment of tendinopathies?. journal of orthopaedic & sports physical therapy, 45(11), 853-863.

  4. Hutchison, A. M., Evans, R., Bodger, O., Pallister, I., Topliss, C., Williams, P., & Beard, D. (2013). What is the best clinical test for Achilles tendinopathy?. Foot and ankle surgery, 19(2), 112-117.

  5. Khan, K. M., Cook, J. L., Kannus, P., Maffulli, N., & Bonar, S. F. (2002). Time to abandon the “tendinitis” myth: painful, overuse tendon conditions have a non-inflammatory pathology.

  6. Khan KM, Forster BB, Robinson J, et alAre ultrasound and magnetic resonance imaging of value in assessment of Achilles tendon disorders? A two year prospective studyBritish Journal of Sports Medicine 2003;37:149-153.

  7. Longo, U. G., Ronga, M., & Maffulli, N. (2018). Achilles tendinopathy. Sports medicine and arthroscopy review, 26(1), 16-30.

  8. Scott A, Docking S, Vicenzino B, et alSports and exercise-related tendinopathies: a review of selected topical issues by participants of the second International Scientific Tendinopathy Symposium (ISTS) Vancouver 2012British Journal of Sports Medicine 2013;47:536-544.

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