Achilles Tendinopathy is a particularly frustrating injury experienced by many runners throughout their career. If not treated promptly, this is an injury that can end up plaguing athletes for years.
Background of Achilles Tendinopathy
A tendon is a structure that connects muscle to bone. When the muscle contracts, the force is transferred via the tendon to the bone in order to generate movement at a particular joint. The Achilles tendon is the name given to the tendon which connects the calf muscles (gastrocnemius and soleus) to the calcaneus (heel bone). It is this muscle-tendon-bone unit which allows us to point our toes – a crucial part in the “push-off” phase of running.
Often wrongly referred to as Achilles “tendinitis” (the suffix “itis” meaning inflammation in the medical world), we now believe that inflammation of the tendon is not the primary pathological mechanism causing pain in the Achilles. Rather, the preferred term “tendinopathy” is used to describe chronic degeneration and failed healing of an inappropriately loaded tendon.
Like most structures in the body, tendons are able to adapt to load – albeit slowly. Achilles tendinopathy develops over time when training loads exceed the ability of the tendon to adapt to the increased stress being placed upon it. It is for this reason that Achilles tendinopathy is thought of as being a chronic overuse injury.
Symptoms of Achilles Tendinopathy
Achilles tendinopathy is usually characterised by a gradual onset, insidious pain felt in the middle of the Achilles tendon around 2-6cm up from where it inserts into the heel. It is not uncommon for pain to be felt right on the insertion into the heel either. This pain soon progresses to being sharp which is felt most during the “push-off” phase off running or when standing on your toes. Patients also complain of morning stiffness at the back of the heel which is alleviated soon after by walking around for a period of time.
Some patients may notice swelling or thickening of their Achilles when comparing it to the other side.
Why does Achilles Tendinopathy develop?
The Achilles tendon, like other tendons, has a very poor blood supply. It is this relative deprivation of blood which explains why the Achilles tendon is prone to injury. Blood is required for structures of the body to heal, grow and adapt. When we train, micro-damage occurs to our muscles, tendons, and bones. Our body senses this damage and acts to repair these structures stronger than before in preparation for further stress that may occur. Largely, blood is the mediator by which this repair occurs. Unfortunately, the poor blood supply to tendons means that healing is slow and this micro-damage occurs at a faster rate than can be repaired. The tendon begins to develop small tears and the chronic tendon injury progresses to Achilles tendinopathy.
In a last ditch attempt to repair the constantly injured tendon – which is being given little chance to repair normally – the body begins to lay down scar tissue and grow new blood vessels into the tendon which are accompanied by pain sensing nerves. This causes a thicker, bulkier tendon which can aggravate the surrounding tendon sheath and result in inflammation called paratendinitis. It is the scarred tendon with small tears; new pain sensing nerves; and associated paratendinitis that is responsible for the Achilles tendon symptoms experienced by runners.
Diagnosis of Achilles Tendinopathy
“No pain, no gain” could not be more wrong here.
It is absolutely crucial that you stop running and see a Sports Doctor as early as possible when you experience the symptoms of Achilles Tendinopathy. There have been many sporting careers stopped dead in their tracks by improper management of this injury. The sooner you seek medical advice, the sooner you will be able to return to running pain free based on the assumption that you have minimised the pathological changes to your tendon described above.
When you see your doctor, they will take a history of your injury; examine your Achilles tendon and lower limb; and likely order some investigations. The diagnosis of Achilles Tendinopathy can be confirmed by medical imaging such as Ultrasound or MRI, however, this is not always needed.
Treatment of Achilles Tendinopathy
Your treatment program is likely to some of these strategies depending on your personal situation and injury characteristics:
- REST: Expect to have multiple weeks off running. This varies greatly amongst individuals and you should liaise with your treating doctor as to when you can begin running again. Common cross-training regimes to maintain fitness gains usually involve swimming/water running.
- Ice and oral anti-inflammatory medications: Used to settle down the inflammation surrounding the tendon. Keep in mind, this is not fixing the underlying injury to your tendon!
- Physiotherapy program: Your Sports Doctor may give you some exercises to begin after some time of rest or they may send you to a physiotherapist who specialises in Achilles tendon injuries. There is very good evidence supporting the use of a rehabilitation program which consists of progressive Achilles tendon strengthening exercises. The most common exercise used is a heel raise which is completed very slowly on the lowering phase to give a good eccentric contraction of the calf muscles.
- Heel lifts/orthotics: Some patients experience pain relief with heel lifts in their shoes because the reduces the load on the Achilles tendon.
- Night splint: A device used to maintain a slight stretch on the Achilles tendon while sleeping to help prevent the morning stiffness associated with the injury
- Corticosteroid (cortisone) injection: A very potent anti-inflammatory that is delivered directly to the area under ultra-sound guidance. The needle is placed into the area surrounding the tendon if inflammation is thought to be present. Once again, this is not treating the underlying injury to your tendon.
- Platelet-Rich Plasma (PRP) injection: Newer treatments are being developed to assist in the healing of tendon injuries. There is some promising evidence to suggest that PRP – where the patient’s own blood is taken from the arm and then injected into the tendon with poor blood supply – may aid in recovery from Achilles Tendinopathy when other treatments have failed.