What is it?

The achilles is the tendon formed as the gastrocnemius and soleus – the calf muscles – join to insert on to the heel bone. The achilles tendon has to tolerate the highest loads in the body – up to 10 times your body weight during running, jumping, hopping and skipping. A painful achilles used to be referred to as tendonitis, but the changes that occur within the tendon do not follow a normal inflammatory/healing process and, because of this, RICE (rest, ice, compression, elevation) does not work with achillles tendinopathy. Instead, there are cellular changes to the tendon and to the arrangement of collagen fibres, as well as its supporting system, the matrix. This does not make the tendon weak, but it does make it difficult for it to tolerate loads. It is correcting this that is at the heart of treatment.

Classic features of achilles tendinopathy are the gradual onset of morning stiffness which may resolve within 5-10 minutes, and stiffness when walking after sitting for long periods. The morning stiffness is often worse on days after a run. The pain/stiffness will typically “warm-up” during the first 5-10 minutes of a run. This feature often stops people seeking help as they can initially run through the pain. But the earlier you seek help, the more likely you will be able to get away with adjusting your load rather than stopping running altogether.

Before moving on to causes and treatment, it is important to mention other potential causes of pain in the area to watch out for as successful treatment will be based on an appropriate diagnosis. Here are a few things to consider:

1. Insertional achilles tendinopathy: this is when the pain is in the heel not the mid-portion of the tendon.

2. Paratendinopathy: the surrounding paratendon is irritated but the tendon structure itself is normal.

3. Posterior impingement of the ankle: THIS will cause pain in the same area but is a very different clinical entity. Forced plantarflexion (pointing) of the ankle will be painful.

4. Partial tear of the achilles tendon: this is easier to miss than you might think and requires very different treatment.

5. Nerve pain that mimics as tendon pain.

This blog will focus on the treatment of mid-portion achilles tendinopathy. A diagnosis can be made clinically – that, is there are no specific scans required, though ultrasound is sometimes used to assess the structure of the tendon. Recent research has also started to look at ultrasound tissue characterisation (UTC) to assess how the tendon may change as a result of load/training. Ultimately it may be useful to help predict how a tendon is tolerating load and, therefore, when you can push it and when you must pull back. At the moment the research is in its very early stages.

What causes achilles tendinopathy?

There are certain risk factors that may lead some people to developing achilles tendinopathy, many of which relate to changes in load through the tendon rather than to a person’s biomechanics. More men are affected than women, and it is more common in the one’s 30s or 40s. Some individuals also have a genetic predisposition to developing tendon pain. Other risk factors include: increasing training; returning to training after a period of inactivity; changes in training surface or footwear; asymmetry in the mechanics of the lower limb (this may relate to weakness/tightness or the dynamic control of a movement).

How to treat it

Diagnosis can occur at different points: the onset of pain may be quite sudden and a reaction to overload – referred to as a reactive tendinopathy and may be severely painful. Or it might be more chronic (longstanding as opposed to severe) – referred to as tendon disarray or degeneration. The treatment will therefore depend on the individual, but ultimately it involves improving the tendons tolerance to load.

Principles of conservative treatment

• Improving the tendons tolerance to load.

• Biomechanical correction

• Manual therapy

• Strength training and correcting training errors

There may be a need to cut running intitially, but there is also general agreement that off-loading the tendon for too long is unhelpful. So the ideal is to calculate the amount of running that can be done without affecting the symptoms – which are mostly latent. So morning stiffness can be a good indication of how the tendon is coping with load.

There is good evidence that slow, heavy load-strength training can improve a tendon’s tolerance to load and this is one of the gold standards for treatment. It is important, though, to avoid overload through other aspects of training while strength training, otherwise it will fail. In my practice, we have found that loading three times a week is optimal, but changes to the tendon do take time, so you need to be patient.

While there may also be specific biomechanical factors feeding into the tendinopathy, the research does not point to any common faults leading to problems in the achilles. So, ideally, each person should have a thorough gait analysis to identify what they need to work on. It may be that their foot position is too rigid, but equally it can relate to overpronation so it is difficult to generalise as these are more or less opposites. I have found biomechanical issues around the hip/pelvis that relate to achilles to be more common than specific flexibility or control issues in the foot or knee.

Far more common than biomechanical problems are training errors. Most patients present with achilles tendon problems when they have radically changed their training load. All the evidence points towards load management as the best way to treat achilles tendinopathy. And it is important to give it time before considering other options – say, three to six months. This is mainly because there isn’t convincing evidence that the other options are better in terms of outcome.

However, if conservative management has failed you then these are the more radical options you could consider:

Injections

Different substances used in injections for the treatment of achilles tendinopathy include:

• Autologous blood (blood taken from you): stimulates a healing process.

• Platelet-rich plasma (centrifuged blood to separate the platelets): stimulates healing.

• Polidocanol: a sclerosant that reduces pain.

• Steroid mixed with saline at high volumes: stripped around the tendon.

Injections around, but not within, the tendon may help, but the research is really lacking. The most popular type of injection given at the moment is a high-volume steroid and saline mix. But many are cautious about using steroid near the tendon because of the potential for weakening the surrounding tissue.

Surgery

There have been quite big advances in surgery and it is possible to have a minimally invasive operation. However, this type of surgery is relatively new and more data is needed to evaluate its effectiveness.

Rebecca Christenson is a physiotherapist at Pure Sports Medicine. To get in touch, please visit puresportsmed.com or follow her on @rebchristenson