Overview

 

Achilles tendinopathy (or previously, achilles tendinitis) is a common condition affecting the achilles and calf region. Like several tendinopathies, it is often brought on through overuse. It is commonly characterised by pain, impaired function and, occasionally, swelling of the Achilles tendon. The Achilles tendon is a vital structure of the lower limb, connecting the calf complex (gastrocnemius and soleus) to the foot by inserting into the heel bone (calcaneus). This tissue structure is responsible for the energy storage and release capacity of the ankle and shank, with the tendon acting as a ‘spring’ to assist in force production during jumping and running movements. For this reason, Achilles tendinopathy is commonly seen in runners and athletes, with research indicating it can affect up to 52% of the running population and 6% of the general population.

This most commonly occurs when training load has spiked and has consequently overloaded the capacity of the tendon complex. Achilles tendinopathy can however also occur in non-athletes due to contributing factors like change in footwear, poor biomechanics, or genetic factors (such as overly pronated feet).

 

Anatomy 

The Achilles tendon, is a robust band of fibrous tissue located at the back of the lower leg. It originates from the convergence of the calf muscles, including the medial and lateral heads of the gastrocnemius and soleus, which form the calf aponeurosis. This fibrous sheet gradually transitions into the Achilles tendon as it descends towards the heel bone, or calcaneus.

Composed primarily of collagen fibers, the Achilles tendon is crucial for transmitting the force generated by the calf muscles to the heel during movement, such as walking, running, and jumping. Its strong attachment to the calcaneus provides stability and support for activities involving the foot and ankle. When overloaded, the tendon can become a ‘reactive tendinopathy’, causing pain during loading exercises such as walking, running and jumping.

 

Common Causes 

Like all tendinopathies, Achilles tendinopathy is most commonly caused by an overload mechanism. As illustrated in the image above, tendinopathies lie on a continuum from reactive, through to tendon disrepair and degeneration, and can be shifted along this continuum through exposure to load. As tendons are the ‘springs’ for muscles, responsible for the storage and release of energy, repetitive explosive movements or activities that load the calf and ankle such as running, are common triggers of Achilles tendinopathy. Other factors that may contribute to developing this condition include tight calves (causing increased loading of the tendon), altered running biomechanics, changes in footwear or kinetic chain deficits that lead to overloading the Achilles and calf complex. 

Diagnosis 

Whilst Achilles tendinopathy is common, there are a range of other structures in close proximity to the tendon that can commonly be misdiagnosed as Achilles tendinopathy. These include (but are not limited to) retrocalcaneal bursitis, hallux rigidus, posterior ankle impingement, peroneal tendinopathy and sural nerve irritations. 

 

At Motus Health & Performance we focus on gaining a thorough understanding of the origins and causal factors of your injury which enables us to differentiate between the possible causes listed above and Achilles tendinopathy. Physical testing will then include tests to rule out differential diagnoses, before moving on to determine which type of Achilles tendinopathy is present. Palpation will be a key component in this part of the assessment, helping us distinguish between insertional achilles tendinopathy (pain at the bottom of the achilles over the heel bone), midportion achilles tendinopathy (pain in the middle of the achilles) or achilles paratendinopathy (inflammation to the tendon sheath, which will often cause a grinding or creaking sensation over the tendon). This is key as it will guide management and exercise rehabilitation programming. 

 

This will also be confirmed with a progression through functional testing that includes double and single leg calf raises and then a variety of jump tests, helping us to quantify your pain and confirm the type of achilles tendinopathy.  

Calf muscle length will also be tested and compared between sides along with single leg calf strength. We test this with force dynamometry, force plates, and functional testing such as single leg calf raises. Pending on the suspected cause, these methods may also be used to assess muscle strength in other muscle groups of the lower limb such as ankle inverters and quadriceps to determine if there are any strength imbalances in the kinetic chain between sides that may be contributing to the Achilles overload.

 

Management 

Achilles tendinopathy management needs to follow specific stages to ensure the condition does not worsen and progress along the tendinopathy continuum. Exercise planning will differ, pending on the stage and type of Achilles tendinopathy. With exercise for tendinopathies, a small amount of pain is accepted (less than 3/10), providing there is no increase in pain following exercise. 

 

The first stage is isometric loading. This involves static calf raise holds that can often have an analgesic (pain relieving) effect. If calf tightness was suspected as a contributing factor, soft tissue release work can be beneficial as an interim muscle relaxant. 

 

Once the tendon has settled and pain has been reduced, heavy slow loading can be commenced. This is vital for rebuilding the tendon structure as resting and un-loading is catabolic (leads to tendon structure breakdown) for tendons. This involves low reps of heavy weighted calf raise style exercises, building back towards single leg loading pending on pain. In this stage, the range of motion used in loading activities will depend on the specific location of your tendon pain. Lower body exercises aiming to correct any strength imbalances in the kinetic chain can also be integrated in this stage to help address the root of the initial problem. 

 

Once strength deficits are addressed, energy storage and release exercises will be implemented. These exercises include jumping and hopping progressions across the plyometric continuum, gradually exposing the calves and particularly the Achilles tendon to increased force and power loads. The extent of this progression will be closely tailored to the specific activity the individual is preparing to resume. This will also dictate how much on-field rehab running is required. At Motus Health and Performance we have a 6 Stage return to run protocol which we coach at Cromer Park on the astro-turf to help you return back to your sporting and running goals. The amount of stages of this protocol required is highly individualised, but is a vital component of ensuring long term prevention of Achilles tendinopathy.

 

Do I need to stop running or playing sport? 

Everyone’s favourite answer – it depends! If your pain is manageable and isn’t inhibiting sports/activity participation, Achilles tendinopathy can be a condition where you continue to play (potentially to a limited capacity) whilst managing with targeted exercises and treatment strategies. However, if you are experiencing high levels of pain, then a brief reduction in sport participation or running can be beneficial to ensure a reactive tendinopathy does not progress to a ‘dysrepair phase’ tendon. This will all depend on your assessment and strength testing results.

 

Expected Timeframes 

The recovery time frame for achilles tendinopathy will differ depending on which phase of the tendon continuum it lies upon. If caught early, a reactive tendon can be settled back to a pain free range within a couple of weeks, whereas a more long standing tendon issue may require progressive treatment and graded exercise loading exposure over several months to return to a pain free level of function.

 

As always, our blog information can serve as a guide to answer the things probably at the forefront of your mind if you’re struggling with achillies pain. Please reach out of this sounds like you, and you’d like an individualised assessment, treatment and return to activity plan.