Expert insights into Achilles tendinopathy assessment with Dr Ebonie Rio

Achilles tendinopathy is a common lower limb condition, however it can often be misidentified, leading to poor outcomes. Posterior ankle pain can be caused by many different sources, and differentiating between a true Achilles tendinopathy and other pathologies can be the key to appropriate management. In this blog we’ll walk through the assessment of Achilles tendinopathy, and touch on how to differentiate between different sources of posterior ankle pain.

If you’d like to learn how expert physio Dr Ebonie Rio assesses Achilles tendinopathy, watch her full Practical HERE. With Practicals you can see exactly how top experts assess and treat specific conditions – so you can become a better clinician, faster. Learn more HERE.

Types of loading

There are two primary types of Achilles tendinopathy: mid-portion and insertional. But to understand the differences between these types, we need to first understand the kinds of load a tendon is exposed to. Tendon loads are broadly categorised as:

• Tensile: Rapid, high magnitude loads (e.g. jumping) which is most associated with mid-portion Achilles tendinopathy.
• Compression: Load experienced at an end range position (e.g. dorsiflexion) which is commonly associated with insertional Achilles tendinopathy.
• Combination: Rapid, high magnitude loads at end ranges (i.e. tensile and compressive loads), such as pushing off from a dorsiflexed position.
• Shearing friction: Low magnitude load on the paratendon during repetitive, mid-range activities (e.g. cycling, swimming). This type of load is most associated with paratendinopathy, which is managed differently to Achilles tendinopathy.

Mid-portion Achilles tendinopathy presents as localised pain around the midpoint of the Achilles and is commonly related to rapid, high magnitude loads. On the other hand, insertional Achilles tendinopathy presents as pain at the Achilles insertion, due to loading in a dorsiflexed position.

It’s also important to understand typical tendon behaviour; tendons are often painful initially, but actually feel better with some warm-up. However, the pain usually increased the day following loading. So now we have an overview, let’s get into the subjective assessment where we’ll start our differential diagnosis process.

Subjective assessment

We want to ask about the behaviour of the athlete’s pain including:

Where: Is the pain focal or diffuse? If the athlete points right to the insertion or mid-portion of the Achilles, that suggests Achilles tendinopathy, whereas diffuse pain is likely related to a different pathology.

Provocative loads: As mentioned above – rapid, high tensile loading resulting in pain likely indicates Achilles tendinopathy, while pain with loads from a dorsiflexed position usually point to insertional tendinopathy. On the other hand, low loads that are not at end range (e.g. cycling), suggests paratendinopathy.

Pain behaviour: Does the area feel better once warmed up? Does it feel worse the next day? If the answers to these questions are yes, we are likely dealing with tendon related pain. If not, consider other causes.

Objective assessment

It’s likely that you will already have a hypothesis in your mind as you enter the objective portion of the exam. This will help to guide the order of your exam so you can first test your hypothesis, then you can gauge the patient’s current level of function (range of motion, strength, endurance, motor control etc.). Below is an overview of some of the key elements of your objective examination.

Observation

Before we begin, we need to do a quick observation of the patient’s lower extremities, looking for scars, gross muscle wasting, and examining footwear. This simple check sometimes catches bits of information the patient has not mentioned.

Load testing

This can include a range of different activities, including those which may have been identified by the patient in the subjective examination. However, below is a list of tasks which are good to run through sequentially. The loading progression is as follows:

• Bilateral calf raises x 5 reps
• Single leg calf raises x 5 reps
• Bilateral vertical hops x 5 reps
• Single leg vertical hops x 5 reps
• Single leg max height jumps x 3 reps
• Single leg max distance forward jumps x 3 reps

Note that for calf raises, we start from plantigrade, but also perform these at a deficit (i.e. in dorsiflexion) to check for insertional Achilles tendinopathy and possible plantaris paratendinopathy.

When we perform load testing, we are not only looking at the quality of the movement side-to-side, but we are looking to check our hypothesis by asking 2 questions:

1. What is your level of pain, 0-10?
2. Can you point to the spot of pain (whether focal or diffuse)?

Typically, patients with mid-portion Achilles tendinopathy experience pain with hopping, but not with slow, controlled calf raises. On the other hand, those with insertional Achilles tendinopathy experience pain with deficit calf raises. If the patient does not experience pain in any of these loading activities, it may be unlikely they have a true Achilles tendinopathy.

Besides pain provocation, we also watch the whole kinetic chain for deviations. For example, as Ebonie demonstrates in the below video from her Practical, patients often alter their jumping mechanics to protect the Achilles:

Calf Capacity

If we are confident we are dealing with a true Achilles tendinopathy (mid-portion or insertional), then we need to examine the capacity of the calf. The heel raise test examines calf endurance and identifies any lower extremity mechanics which may be related to the patient’s pain. However, it’s important to note that the heel raise test is not considered an accurate measure of plantar flexor strength – dynamometer testing should be used when assessing maximum plantar flexor strength.

In the below snippet taken from her Practical, Dr. Ebonie Rio explains how she identifies kinetic chain deviations:

Posterior Ankle Differential Diagnosis

So, using the subjective and objective assessments thus far, you’re wondering whether the patient has a true Achilles tendinopathy, or may be experiencing another pathology – but what other pathologies should you be on the lookout for? There are several areas which may be relevant to include in your exam. Some possible pathologies include:

Achilles paratendinopathy: Irritation of the Achilles tendon synovial sheath, related to repeated mid-range loading (e.g. cycling). The pain is typically diffuse and with a stethoscope you may hear crepitus as the ankle is taken through dorsiflexion and plantarflexion.

Plantaris paratendinopathy: Irritation of the plantaris tendon synovial sheath. This can appear as medial Achilles pain during deficit calf raises and/or pain with passive dorsiflexion.

Sural nerve irritation: Sensitivity of the sural nerve, which presents as pain on palpation of the lateral Achilles while in plantigrade. Note that this is not a common pathology.

Posterior ankle impingement: Deep posterior ankle pain experienced at end range plantarflexion, even if performed passively by the therapist. This is common in athletes who engage in repetitive plantarflexion sports such as soccer or dancing.

Flexor Hallucis Longus (FHL) paratendinopathy: FHL synovial sheath irritation which may present with crepitus through a stethoscope during tendon gliding. There may also be pain with strength testing, as Dr Ebonie Rio demonstrates in the below video excerpt from her Practical:

Wrapping Up

There are multiple possible sources for posterior ankle pain, your assessment must determine whether the patient truly has Achilles tendinopathy, or if a different pathology may exist, as this will determine the kind of loading program you prescribe. Often, patients can become frustrated with loading programs targeting Achilles tendinopathy, as they actually have a different pain driver. With a thorough assessment, you’ll be confident in your differential diagnosis, and thus your prescription of the appropriate loading program.

For a full walk-through on how to master your assessment of Achilles tendinopathy check out Dr. Rio’s full Practical HERE.