Why does my Achilles hurt?

Did you know that there approximately 7 million runners in the UK and of those, 10% of them will be struggling with Achilles tendinopathy as you’re reading this?!
Did you know that there approximately 7 million runners in the UK and of those, 10% of them will be struggling with Achilles tendinopathy as you’re reading this?! That’s 700,000 people currently struggling with pain in their Achilles tendon. Interestingly 58% of those with this injury are male.
The Achilles tendon is the largest tendon in the body and it attaches your calf muscle complex to your foot. There are a number of factors that increase your risk of developing Achilles tendinopathy. Some of these factors you can modify and alter and therefore change to your benefit and some of them are what we term ‘non-modifiable’ i.e. you can’t do anything about them.
So risk factors that you CANNOT change are;

  • Previous tendinopathy in the same region or a recent injury
  • Getting older
  • Your gender (men are more likely to be affected than women)
  • Exposure to steroids.
  • Other metabolic health conditions such as Diabetes and high cholesterol (though these may be modifiable in some cases).

However the factors that ARE modifiable but likely to increase the chance of you developing this problem are;

  • Having reduced muscle power/strength in the calf muscles.
  • Reduced ankle dorsiflexion (flexibility in the ankle in its ‘upwards’ position).
  • Carrying increased weight, interestingly more so in the abdominal region!
  • Foot alignment such as increased pronation (though there is still a question mark around how important this risk factor really is).

Out of all of those modifiable risk factors, the key one is the calf muscle strength. However research has shown that a whopping 70% of patients don’t do their exercises as advised by their physiotherapist! So you can see that there is major risk factor for ongoing Achilles problems if the exercises aren’t performed as directed.

Both the physiotherapist and the patient need to understand the importance of generating a rehab programme that the patient can comply with. This is critical to success. If the rehab programme is the right one and complied with adequately, then the patient should start to see results after approximately 6 to 8 weeks of training.
So when it comes to thinking in more detail about triggering factors within the context of modifiable risk factors of Achilles tendinopathy; the extrinsic risk factors that are most commonly linked are;

  • Sudden changes in load such as return to exercise after a break.
  • Training errors. More on what these are below.
  • Your general activity levels (interestingly even minor changes in activity from a completely sedentary level can cause problems in the Achilles). We do see Achilles tendinopathy and people who are not particularly active and it’s most likely due to this change in their baseline, albeit low, activity levels.
  • Changes in footwear such as changing from a larger heel-toe drop to a very flat shoe. This can suddenly change the impact and load through the tendon and cause problems.
  • Sudden changes in training surface. For example running on softer surfaces can increase the load on the Achilles tendon because it has to work harder to get the rebound through the foot and the floor.

Training Errors
Training errors can be relevant to any tendon in the body where you have;

  • A sudden spike or change in load such as integrating hill running into a weekly pattern
  • Increasing the intensity or speed of your running or alterations in your training program due to where you are in a stage of season in relation to competition.
  • Sometimes even a change in the training session duration can increase the load to the point where the tendon cannot cope well.


After the easing of lockdown, we’re definitely seeing an increase in session frequency as people try to get back to the activities they enjoy as well as an overall increase in their weekly distance. All of these factors we would consider training errors and are worth considering if you’re developing pain.
It’s not just a tendon issue; it can impact you as a whole person. A study by McAuliffe et al in 2017 demonstrated that Achilles problems have a significant impact on people’s lives. Having a problem with your Achilles tendon can often lead to fear and uncertainty around potential damage and also concerns about the future. There can be confusion around treatment and the benefits of rest versus running. So we know that tendon problems particularly around the Achilles region can cause significant impact on people‘s quality of life.

Facing the fear.

Are you scared to move your Achilles? Are you worried about causing longer-term damage to the tendon if you do endurance activities or strength training? If so then you may be experiencing Kinesiophobia. Kinesiophobia is the fear of movement. In current research the level of Kinesiophobia could explain a 35% recovery rate of heel-rise endurance (how many times you can single leg calf raise before fatigue). So understanding and being reassured by your expert physiotherapist about what is suitable and what isn’t for your tendon recovery can go a very long way to enhancing your healing journey. Typically we would say that Achilles tendinopathy is slow to settle and quick to aggravate. It’s important that patients understand this because treatment can take time to resolve - sometimes up to 12 months. And it can come back. One study suggested that there is a 15% new recurrence rate of symptoms within five years. With 20% of people continuing to have symptoms and ongoing strength deficit at five years. And so with this in mind, rehab relies heavily on consistent and ongoing self-management for patients with the guidance of the physiotherapist. It’s important that people realise that it can take 2 to 3 months to start to see that pain improve but then they need to maintain their strength gains after the pain has resolved. What do we mean by load?

Load is stress or force through the tissue and this creates an Achilles internal force. Here’s an example of what your tendon has to deal with:

A 10 km run with an average time of 50 minutes would result in approximately 7500 steps or 3750 steps per leg.
At 4500 Newton’s per step, that’s an Achilles load of 16,875,000N per leg!

So each extra kilometre can seem negligible but it places extra stress through the tendon. How amazing are our bodies to cope with it most of the time?!
It’s worthwhile remembering that tendinopathy is an imbalance between the wear rate and repair rate. We get stronger by putting load through the tendon but if you are not allowing adequate recovery time you will get overload and therefore issues. Therefore load modification is essential to improvement.

Your Physiotherapist will devise a program specifically for you as an individual patient to enable you to take away the ‘high stress’ activity (the problem load) initially. We will teach you to use a
pain monitoring approach and then once we have control of that to introduce further elements of strength training. It usually takes 8 to 12 weeks of loading before we can start to see the benefits of the Physiotherapy program. Alongside this it’s worth remembering that if there is absolutely no improvement in the tendon after this period of time, then it may be that there is a flat or small longitudinal tear that we would need to refer you on to have investigated further with imaging. These don’t tend to do so well with heavy loading. Other things to consider are the use of topical anti-inflammatories. They have been shown to be better than placebo but usually only for a short sharp duration of maximum of five days if the tendon is visibly inflamed/swollen and tender to touch. It’s also worth noting that postmenopausal women have an increased likelihood of developing tendon problems whether that’s in the Achilles or the gluteal tendons because of a drop in their oestrogen levels. We know that oestrogen stimulates tendon cells and therefore the drop in oestrogen can reduce tendon cell recovery. This doesn’t mean that we can’t load people appropriately but it’s worth bearing in mind with regards to managing pain and exercise.

So hopefully you’ve found that run through of Achilles tendinopathy useful. However do remember that if you develop pains in other areas when you’ve changed your activity levels, you should pay attention!

Pain in these areas might indicate that you are at risk for developing tendinopathy. 

 
  1. Pain in your Achilles tendon… if you have an olive-sized bump you already have Achilles tendinopathy and you should start your physio. 
  2. Pain in your patella tendon, located just below your kneecap or patella. 
  3. Pain in the buttock, often where your hamstring tendons attach to the pelvis. 
  4. Pain along the outer portion or lateral side of the knee. Although ITB syndrome may not be classic tendinopathy, you do not want it to become worse by ramping up your training. 
  5. Pain along the medial or inner part of your lower tibia.  Although this is not considered classic tendinopathy, medial tibial stress syndrome can also lead to a long recovery if it is allowed to worsen.   

So we’d encourage you to see your Physiotherapist if you are getting aches and pains that need expert management. After all, Achilles pain needn’t be something you put up with! Thanks for reading.

Jennifer Searle MSc Sport & Exercise (Sports Injury).
Owner and Specialist Musculoskeletal Physiotherapist
May 2021