Calcaneal stress fractures often begin subtly, which is one of the reasons they are frequently mistaken for plantar fasciosis. Most patients cannot recall a single injury or traumatic event. Instead, the pain develops gradually over days or weeks and progressively worsens as the heel bone becomes increasingly overloaded.
The most common symptom is a deep ache within the heel. Unlike plantar fasciosis, where patients usually point to the attachment of the plantar fascia on the inside of the heel, people with a stress fracture often describe the pain as being "inside the bone" or "deep within the heel." This distinction is not always obvious, but it can provide an important clue during the clinical assessment.
Pain usually increases with activity. Early in the condition, patients may notice discomfort only during running, long walks or sporting activities. As the fracture progresses, the pain often develops earlier during activity and takes longer to settle afterwards. Eventually, everyday walking and prolonged standing may become painful, and some patients begin to limp to avoid loading the affected heel.
Unlike plantar fasciosis, severe first-step pain in the morning is often absent. Instead, patients commonly report that the heel feels progressively worse the longer they remain on their feet. They may initially tolerate walking quite well, only to find that the pain steadily builds throughout the day as repetitive loading continues.
A recent increase in activity is a common feature. Many patients report increasing their running distance, beginning a new exercise programme, returning to sport after a break or starting an occupation requiring prolonged standing shortly before the symptoms developed. Identifying these changes often provides valuable clues that the heel bone, rather than the plantar fascia, has become overloaded.
Tenderness during examination is also different. Pressing directly into the plantar fascia attachment may reproduce only mild discomfort, whereas squeezing the calcaneus from the sides often produces significant pain. This manoeuvre, sometimes referred to as the calcaneal squeeze test, increases compression through the heel bone and may suggest a stress injury when positive. However, it is not completely specific and should always be interpreted alongside the patient's history and imaging findings.
As the stress fracture progresses, pain may occur even at rest. Some patients begin to experience aching after sitting or lying down, while more severe cases may become painful during the night. Persistent night pain should never be ignored, as it also raises the possibility of infection, inflammatory disease or, rarely, bone tumours. Further investigation is essential whenever the clinical picture is atypical.
Swelling is usually minimal or absent, which distinguishes calcaneal stress fractures from many acute fractures. Bruising is uncommon because there has been no major traumatic event. The absence of visible swelling often leads patients to underestimate the seriousness of the injury and continue participating in sport, increasing the risk of progression.
Many patients initially receive treatment for plantar fasciosis because of the similarity in symptoms. They may complete stretching programmes, wear orthotics, receive shockwave therapy or even undergo injections without meaningful improvement. When heel pain fails to respond as expected, particularly in the setting of increasing activity, a calcaneal stress fracture should be considered.
MRI is the investigation of choice when a stress fracture is suspected. It can identify bone marrow oedema, which often precedes a visible fracture, and detect small fractures that are not apparent on standard X-rays. Early diagnosis allows activity modification before the injury progresses, reducing the risk of delayed healing or a more significant fracture.
The most important message is that heel pain which progressively worsens with activity should not automatically be assumed to be plantar fasciosis. Recognising the characteristic symptoms of a calcaneal stress fracture allows appropriate investigation and management before a relatively minor stress injury develops into a more serious problem.