Achilles Tendon Pain
(This article by Matt Phillips originally appeared in Running Fitness Magazine, May 2015)
In Greek mythology, Achilles was a hero of the Trojan War who despite managing to slay arch rival Hector outside the gates of Troy sadly became most famous for dying from an arrow shot into his heel. Rather ironically, had Achilles been shot anywhere else he would have probably survived – a momentary oversight by his mother who when dipping her baby into the water of a magic river to give him super protective powers forgot about the heel she was holding him by.
Any runner who has suffered from persistent pain in the Achilles tendon will doubtlessly agree that it is a fitting name. As the thickest and longest tendon in the human body (normally around 15cm), the Achilles tendon connects the calf muscles (gastrocnemius and soleus) to the heel bone (calcaneus). As we can see in the image below, the tendon starts near the middle of the calf and becomes thinner as it approaches the insertion at the heel bone, and though the precise location of discomfort can vary, many runners have found out the hard way that what may start off as a slight niggle can soon turn into months and sometimes years of frustration.
The good news is, if treated correctly, runners can recover from Achilles pain sooner than many have had to endure. However, success does depend on accurately identifying the source of the issue and taking appropriate steps to ensure it goes away and stays away.
What Does The Achilles Tendon Do?
The Achilles tendon is designed to deal with the loads that your body absorbs and uses to move. When you walk, these loads are the equivalent of approximately four times your body weight; when you run they move up to eight times your body weight. The calf muscles (gastrocnemius and soleus) that join to the heel bone via the tendon are responsible for pushing the front of the foot downwards, so when putting weight on the foot they are involved in both lifting the heel off the ground (concentric muscle contraction) and controlling (decelerating) the heel when it is moving down towards the ground (eccentric muscle contraction). The gastrocnemius crosses the knee joint and attaches to the upper leg and is therefore also involved in bending (flexing) the knee joint (concentric muscle contraction) and controlling (decelerating) the straightening of the knee joint (eccentric muscle contraction).
Why Is My Achilles Tendon Painful?
When faced with Achilles pain, it is important to distinguish between the following:
Achilles Tendinitis – When you see a word ending in ‘-itis’, it implies that the underlying problem at hand is excessive inflammation. Though inflammation is a natural, important response to the demands of exercise and indeed part of the process by which we become stronger, over exertion can result in too much of an inflammatory response, inhibition of joint movement and pain. With regards to running, Achilles tendinitis is generally an acute reaction to a sudden increase in distance, intensity or frequency.
Achilles Tendinosis – Though inflammation was once thought to be the source of most Achilles issues, modern research has shown that this is not the case. Often it is the tendon’s inability to deal with increased loads that is the problem, due to a physical decline in its structure over a period of time. This should be noted by runners as traditional treatment protocol such as anti-inflammatories and ice may not help if the issue is not one of excess inflammation. Swelling may well still be present, but it is thought to be due to changes in water movement inside the tendon as opposed to inflammation. The suffix ‘–osis’ at the end of a word implies a ‘change of state’ so Achilles tendinosis is used to describe this structural decline. But don’t let this alarm you. Our body is constantly breaking down and rebuilding bits of itself; a tendinosis simply implies the structural state has over time become sufficiently compromised to now require modification of habitual activity (either less running or stop for a while) and most importantly some specific strengthening work to restore its structural integrity so that it can once again happily deal with the load demands of walking, running, jumping, etc. Achilles tendinosis is typically the result of overuse over a period of time. The soreness and stiffness is a protective reaction. We should be thankful for it and make the necessary changes, not curse it or try to ignore it.
In the case of runners, pain in the Achilles may well involve a combination of tendinitis and tendinosis, which is why most modern therapists use the word tendinopathy to refer to the injury. The word is further divided in order to clarify the location of the injury, which is important as the type of treatment and rehabilitation can differ according to where the location of the tendinopathy is:
Insertional Tendinopathy – pain is at the attachment point on the heel bone (calcaneus) and worsens when the top of the foot is pulled backwards towards the shin (dorsiflexion). This is because the action causes the tendon to become compressed against the heel bone, meaning any activity that encourages dorsiflexion (e.g. stretching or lowering heels over the side of a step) should be avoided in early rehabilitation as it could aggravate the tendon further and delay recovery.
Mid-portion Tendinopathy – pain and swelling occur higher up away from the heel bone and worsens when excessive load is sent through the tendon. In this case, activities that promote load increases (such as running) are likely to need modifying in order to avoid delaying recovery.
Other Sources Of Pain
In the investigation of Achilles tendinopathy, other potential sources of pain need to be ruled out. One example is irritation of one of the bursae found under the Achilles tendon. A Bursa is a fluid filled sac with the function of reducing friction; the retrocalcaneal bursa reduces friction between the Achilles tendon and the heel bone (calcaneus) whilst the retroachilles bursa acts between the skin and the Achilles tendon. Excessive load can cause these bursae to swell and become very painful.
The tendon of the Tibialis Posterior runs close to the Achilles tendon but branches off on the inside to pass behind the inner ankle. Symptoms can be similar to Achilles tendinopathy as the Tibialis Posterior muscle shares functions common to those of the calf muscles, so examination of symptoms does need to rule this out.
Where function has been compromised sufficiently to warrant visual examination of the tendon, an MRI or ultrasound may be used. The images can either confirm or dismiss any paratenonitis (swelling of the surrounding sheath), swelling of the bursae (retrocalcaneal bursitis or retroachilles bursitis) and view the structural state of the tendon itself.
Taking anatomy into consideration, our Greek hero Achilles is more likely to have died from an injury to the posterior tibial artery behind his ankle rather than to the Achilles tendon, which makes sense when we imagine how his mother would have held him as a baby. Nice point for dinner parties.
Rehabilitation For Achilles Tendinopathy
Appropriate rehabilitation of Achilles tendinopathy depends hugely on at what stage of tendinopathy the tendon is at. The number one rule is, don’t ignore symptoms or try and run through them. In the early stages (reactive tendinopathy), the structure of the tendon is minimally effected so a little activity modification and strengthening work may be all you need to recover and get your training back on track. However, if you choose to try and soldier on and continue to expose the tendon to excessive load, its structure will start declining (tendon disrepair) and loss of function will soon follow. Rehab will take longer. Keep ignoring it and not making the necessary changes and you will get to the stage where function is severely compromised (degenerative tendinopathy) and you run the risk of not running happily ever again.
This is not meant to be scaremongery. My intention is to highlight the fact that Achilles tendinopathy has stages and you the runner are in control of how far you let things escalate. Therapists, taping and medication may be able to provide temporary pain relief but ultimately it is suitable self management that will determine your recovery.
Conclusion: Get Professional Guidance
Hopefully this article has shown how an accurate diagnosis of what type of Achilles issue you have is important in determining what type of exercises and activity modification you will need to get onto and complete the ladder to full recovery.
Bear in mind that complete rest is rarely the answer (despite what some GP’s still sadly recommend). The recovery ladder will typically involve a gradual increase in loading, something that sitting with your feet up for two weeks will certainly not do.
Massage nearly always has a place in the road to recovery but again it will not help your tendon get any stronger. Stretching may feel good but in many cases it is the last thing your tendon needs and can even slow down recovery (by increasing compression).
Foam rolling can be useful instead of stretching but again it’s how you do it that counts (they are not supposed to be torture devices!). Stopping your rehab the moment you start to feel better is a common mistake too; rehab needs to be progressed gradually and consistently even after you start seeing benefits. In fact, in most cases the rehab becomes ‘prehab’, i.e. a conditioning program your body will need for ever if you really want to reduce the risk of running into problems again. The biggest indicator of injury risk is if you have been injured before, so the message is learn from your injuries and make changes.