Case Study – Plantar Fasciitis, Achilles Tendonitis, Peroneal Tendonitis

Differential diagnosis including plantar fasciitis and Achilles tendonitis

Plantar fasciitis is an extremely common condition seen amongst podiatrists in the clinic today. However, occasionally patients can be misdiagnosed due to pain in other parts of the foot anatomy and conditions that give symptoms similar to that of plantar fasciitis. These conditions include, but are not limited to, those that can cause heel pain. Achilles tendonitis, and peroneal tendonitis are other conditions to consider.

Case Study – Plantar Fasciitis and Peroneal Tendonitis

A 36-year-old female arrives at the Sydney heel pain clinic complaining of heel and arch pain. She informs the podiatrist that she thinks she is suffering with plantar fasciitis but is not 100% sure. She describes pain in the base of the heel and pain in the arch of the foot. It becomes apparent that she does not have pain along the calf muscle or the Achilles tendon, such as can be seen in patients with Achilles tendonitis. This patient is approximately 10 kilos overweight but does not suffer with any other health conditions. She has been experiencing severe foot pain for more than 6 months and is becoming increasingly frustrated with her inability to exercise. She has ceased all physical activity but informs the sports podiatrist that she was a keen runner and cyclist. She has limited her exercise to swimming but is not enjoying this type of activity. She has never experienced heel pain before and until recently she was unaware of conditions such as plantar fasciitis. This patient was given treatment advice by a local sports medicine doctor, but found no improvement following the consultation. To this end she was referred to the imaging centre for an MRI. The MRI confirmed plantar fasciitis and tendonitis of the peroneus longus.


Due to the anatomy of the plantar fascia, running distally from the base of the heel through the arch of the foot and into the base of the toes, which crosses the line of the peroneus longus tendon, it is not uncommon for patients to be misdiagnosed. The diagnosis of plantar fasciitis is often given, when in fact there is also or instead, peroneal tendonitis. The treatment of these two conditions is obviously very different.

Patients with Achilles tendonitis can also experience pain that radiates into both sides of the heel bone, and sometimes further down which can be felt in the base of the heel. Once again, patients with Achilles tendonitis can sometimes think that they are suffering with plantar fasciitis when in fact these two conditions are both very different.

Likewise, patients with plantar fasciitis can also experience pain that radiates along both sides of the heel bone, towards the Achilles tendon. Once again, these patients may interpret these symptoms as Achilles tendonitis when in fact this is not the case. In both of the above cases it is not usually necessary for the sports podiatrist to request medical imaging. Physical assessment should be sufficient in order to differentiate between these two conditions and make an accurate diagnosis.

Physical Assessment for Plantar Fasciitis, Achilles Tendonitis, Peroneal Tendonitis

The sports podiatrist carried out a physical assessment and was able to diagnose plantar fasciitis and peroneal tendonitis. Firm pressure was applied to the base of the heel around the attachment of the plantar fascia. This reproduced a familiar pain which the patient had been experiencing and the sports podiatrist confirmed that she did in fact have symptoms of plantar fasciitis. Firm finger pressure was also applied through the arch of the foot along the medial, central and lateral slips of the plantar fascia. Proximally, and distally, this did not elicit pain or symptoms that the patient had been experiencing. However, when firm pressure was applied through the mid portion of the foot the patient retracted her leg due to the pain. The podiatrist then changed direction of palpation, and applied gentle force from the lateral to the medial aspect of the foot from the cuboid bone to the navicular bone, which follows the line of the peroneus longus tendon. It was through this area that the patient reported significant pain. The sports podiatrist informed the patient that she also had peroneal tendonitis in addition to her plantar fasciitis. The MRI report confirmed this. With the patient lying prone, firm pressure was applied to the medial aspect of the calf muscle distally and along the shaft of the Achilles tendon. Pressure was also applied around the insertion of the Achilles tendon onto the posterior aspect of the heel bone. No pain was reproduced. The podiatrist informed the patient that she did not have Achilles tendonitis.

Treatment for Plantar Fasciitis, Peroneal Tendonitis

The sports podiatrist explained to the patient that plantar fasciitis can often be treated with strapping or orthotics. Peroneal tendonitis is a condition that can also respond to the above. Other factors to consider are things like footwear, stretches and ice packs. However, due to the extreme pain that the patient described during physical assessment, and based on her inability to walk comfortably without limp, the sports podiatrist informed the patient that her condition seemed to be too acute for the above treatments to be effective. The patient had also informed the podiatrist that when stationary, she felt throbbing and heat. To this end, the podiatrist inform the patient that the quickest, and most effective and the most comfortable treatment for her, was the use of an immobilisation boot.

Sydney Heel Pain Mobile Application for Plantar Fasciitis and Achilles Tendonitis

The sports podiatrist explained to the patient that a large part of her recovery would be determined by her being compliant with treatment. She was informed that it was important that she avoid doing things that irritate the plantar fascia and the peroneal tendon, and start doing things that assist healing. Because plantar fasciitis and Achilles tendonitis both cause heel pain, she was instructed to install the Sydney Heel Pain mobile app on her phone. The app would contain all of the necessary information that she needed. The treatment advice contained in the application would also be beneficial for the treatment of the peroneal tendonitis. The information included, but was not limited to, things such as footwear choice, stretching and the application of ice packs.

6 Week Review

This patient came back to the clinic for a review of her plantar fasciitis after 6 weeks. The boot was removed and she walked around the room freely, without any pain. She informed the podiatrist that she had on occasion removed the boot and walked for approximately 2 to 3 hours, and did not feel much pain. The podiatrist concluded that the peroneal tendonitis and the plantar fasciitis had both improved significantly. The patient was happy with progress and was booked in for a follow up appointment a week later where by a biomechanical assessment could be carried out to determine the cause of her conditions.

This case study is not general advice. If you have plantar fasciitis, Peroneal tendonitis or Achilles Tendonitis you should consult with a sports podiatrist.


Written by Karl Lockett