The development of insertional Achilles tendinopathy is linked to repetitive microtrauma or overuse of the tendon, leading to collagen degeneration, disorganisation, and impaired tendon structure. This process is termed tendinopathy, and it leads to increased tendon thickness and a loss of tensile strength. Common risk factors include excessive physical activity, poor footwear, sudden increases in activity level, and biomechanical abnormalities such as overpronation, tight calf muscles, or abnormal foot mechanics.

Patients with insertional Achilles tendinopathy typically present with pain localised at the Achilles tendon’s insertion on the calcaneus. The pain is often aggravated by activity, especially with activities that involve heel striking, such as running and walking. Early-stage pain may only occur during or after physical activity, while more advanced stages may present with chronic pain that persists even at rest. Swelling and tenderness at the insertion site are also common. In severe cases, patients may experience difficulty with basic activities like walking or climbing stairs.

Diagnosis of an insertional Achilles tendinopathy can’t always rely on pain on palpation as this has high sensitivity but low specificity, essentially yielding potential false positives. Assessing pain location during loading assessments could improve the accuracy of the diagnosis and lead practitioners to a more appropriate rehabilitation progression. 

A clinical history outlining the onset and description of pain, injury and activity history and general medical history can assist in diagnosing Achilles tendinopathy. A physical examination of the affected ankle will confirm the diagnosis. This may include palpation over the achilles tendon insertion on the calcaneus where tenderness, thickening and swelling may be identified. Limited dorsiflexion and plantarflexion may be present and special tests such as single leg heel raise, standing calf raises and single leg hops on the spot can confirm the clinical diagnosis.

If necessary, imaging can be used to confirm the diagnosis and show the severity of the injury. Ultrasound can show tendon thickening and calcifications or tears. An x-ray can be taken if there are suspected calcaneal spurs and other suspected bony pathologies or abnormalities. An MRI will provide a more detailed image of the achilles tendon, showing degenerative changes, tendinosis and bony pathologies. 

Load management and activity modification  

The foundation of physiotherapy for insertional Achilles tendinopathy involves load management. The principle is to modify the intensity and frequency of activities to reduce tendon overload, while ensuring adequate time for healing. Gradual load increases, rather than abrupt changes, are crucial in preventing further injury. Avoiding high-impact activities or eccentric loading exercises during flare-ups can help prevent exacerbation of symptoms.

Manual therapy

Manual therapy, such as joint mobilisations, can address restricted ankle mobility that may contribute to abnormal load distribution during movement. In addition, modalities such as heat and cryotherapy may provide symptomatic relief, although evidence for their efficacy varies. These methods may be used in conjunction with exercise therapy but should not be the sole treatment.

Isometric loading

Isometric loading is typically a good starting point for many patients presenting with insertional Achilles tendinopathy who are unable to perform isotonic exercises with acceptable symptoms (i.e. without significant pain). Loading in this phase is typically focussed around heavy resistance with minimal symptoms to trigger the remodelling and resynthesis of collagen within the tendon. 

Heavy slow resistance exercises

The progression from the isometric phase is moving into slow heavy isotonic exercises within a range of motion without triggering significant pain. The use of heavy loads comes from the theory of mechanotransduction, which states that mechanical load will stimulate cellular healing. Further, the research states that the higher the magnitude of load the greater the cellular response. Slow, controlled heavy exercises (aiming for 2-3 seconds per concentric repetition) through full ranges of motion are essential for building tolerance and managing Achilles tendon loads.

Eccentric strengthening exercises

Eccentric exercise has become a cornerstone of tendon rehabilitation. Several studies have demonstrated that eccentric loading of the Achilles tendon can stimulate collagen synthesis, improve tendon strength, and reduce pain. The classic protocol involves performing eccentric calf raises, focusing on the lowering phase, which should be slow and controlled. This has been shown to improve tendon remodeling and reduce symptoms in individuals with Achilles tendinopathy. The “Alfredson protocol,” which consists of a series of heavy, slow eccentric calf exercises, is one of the most well-researched and effective regimens.

Patient education and self-management

Education on the nature of insertional Achilles tendinopathy and its management is key to achieving optimal outcomes. Patients should be informed about the importance of consistent rehabilitation, proper footwear, and avoiding sudden increases in activity intensity. A gradual return to sport or activities is essential to ensure long-term recovery and prevent recurrence of symptoms.