Calcaneal stress fractures are overuse injuries in which repetitive loading produces microscopic damage within the heel bone faster than normal remodelling can repair it. They are less common than tibial or metatarsal stress fractures, yet they are an important cause of persistent heel pain in runners because early symptoms can resemble plantar fasciopathy, Achilles-related pain or a simple heel bruise. Delayed recognition may allow a bone stress reaction to progress to a visible fracture. Fortunately, most calcaneal stress fractures are considered low-risk injuries and heal with conservative care. Effective management, however, requires more than rest: clinicians and runners must identify the training, biomechanical, nutritional and medical factors that disturbed the balance between load and bone capacity.
Mechanism and Risk Factors
The calcaneus transmits substantial forces at initial contact and helps transfer load from the hindfoot to the forefoot during stance. Running subjects it to repeated compression through ground-reaction forces and the opposing pull of the Achilles tendon and plantar fascia. Bone normally adapts to these demands, but abrupt or excessive loading creates microdamage. When osteoclastic resorption temporarily exceeds new bone formation, a stress reaction may develop and eventually form a fracture line.
A rapid increase in mileage is a classic precipitant, but intensity, hills, speed sessions and training frequency are equally important. Returning too quickly after inactivity, changing to a harder surface, beginning military-style conditioning or making a sudden footwear transition may also increase load. Fatigue can alter running mechanics and reduce muscular shock attenuation. Individual factors include previous bone stress injury, low bone mineral density, inadequate recovery, smoking, certain medications and conditions that impair calcium or vitamin D metabolism.
Low energy availability deserves particular attention. When dietary energy is insufficient for both exercise and normal physiology, hormonal and skeletal health may deteriorate. This process forms part of relative energy deficiency in sport (RED-S) and can affect runners of any sex. Menstrual disturbance in women, reduced libido or testosterone in men, recurrent injuries, weight loss and restrictive eating are warning signs rather than markers of athletic fitness. Older runners and athletes with osteoporosis or systemic illness may sustain an insufficiency-type injury under otherwise ordinary loads.
Clinical Presentation and Diagnosis
The typical symptom is gradually increasing pain beneath or around the heel. Initially, discomfort may occur only near the end of a run and settle with rest. As injury severity increases, pain begins earlier, persists after exercise and may interfere with walking. Examination commonly reveals focal tenderness over the posterior or plantar calcaneus and pain when the medial and lateral sides of the heel are compressed together—the calcaneal squeeze test. Swelling, warmth or an antalgic gait may be present. Nevertheless, no single examination finding is conclusive.
Differential diagnosis is broad. Plantar fasciopathy usually causes medial plantar heel pain that is prominent with the first steps after rest, while Achilles tendinopathy is centred near the tendon insertion or midsubstance. Other possibilities include heel-pad syndrome, retrocalcaneal bursitis, nerve entrapment, inflammatory disease, infection and, less commonly, tumour. A careful history should therefore examine training change, pain behaviour, nutrition, menstrual or endocrine health, medications and previous fractures.
Plain radiographs are normally the first imaging test because they can identify alternative pathology and may later show sclerosis or a fracture line. Early radiographs, however, are frequently normal because bone changes take time to become visible. A normal X-ray must not override a strongly suggestive clinical picture. Magnetic resonance imaging is the preferred confirmatory investigation because it detects marrow oedema and fracture morphology without ionising radiation. Computed tomography can define cortical detail or assess uncertain healing, whereas bone scintigraphy is sensitive but less specific and is now used less often.
Treatment and Rehabilitation
Most calcaneal stress fractures heal without surgery. The immediate priority is to stop running and other painful impact activity. Weight-bearing should be guided by symptoms: a runner who can walk comfortably may need only activity modification and supportive footwear, whereas substantial pain, limping or pain during daily activities may justify a walking boot and temporary use of crutches. Analgesia should be discussed with a clinician; repeated use of non-steroidal anti-inflammatory drugs is sometimes discouraged because of concern about bone healing, although human evidence is not definitive.
Rehabilitation should preserve fitness without repeatedly provoking the injury. Deep-water running, swimming or cycling can be introduced if completely pain-free. Calf, foot and proximal lower-limb strength, balance and movement control should be rebuilt progressively rather than treating the heel in isolation. Clinicians should assess energy intake, protein, calcium and vitamin D, but supplements are not substitutes for adequate nutrition and should target demonstrated deficiency or clinical need. Recurrent injuries, RED-S features or unusual fractures warrant medical investigation, potentially including blood tests and bone-density assessment.
Return to running should be based on function rather than a fixed date. The athlete should first be pain-free in daily life and able to walk briskly, hop and perform relevant strength tasks without symptoms during the activity or the following day. A graded walk–run programme can then begin on level ground, with recovery days between sessions. Duration should increase before speed, hills and consecutive running days. Pain that returns during a session, later that day or the next morning signals that loading has advanced too quickly. Uncomplicated injuries may settle within approximately six to eight weeks, but complete return to previous training often takes longer and varies with injury grade and underlying risk factors.
Prevention and Conclusion
Prevention depends on matching training stress to the runner’s capacity. Mileage and intensity should rise gradually, hard sessions should be separated by recovery, and persistent focal heel pain should not be “run through.” Strength training, sufficient sleep, adequate energy intake and timely replacement of unsuitable footwear can support tissue capacity, although no shoe can compensate for excessive load. Training plans should account for recent illness, inactivity and life stress as well as weekly distance.
Calcaneal stress fractures illustrate the continuum of bone stress injury: a potentially reversible stress reaction can become a fracture if warning symptoms are ignored. Early clinical suspicion, appropriate MRI when required, protection from painful loading and correction of contributing factors usually produce an excellent outcome. For runners, the safest route back is neither prolonged complete inactivity nor a rushed return, but progressive loading guided by symptoms, function and bone health.
References
American Academy of Family Physicians (2003). “Common Stress Fractures.” American Family Physician, 68(8), 1527–1532. https://www.aafp.org/pubs/afp/issues/2003/1015/p1527.html
Mayer, S. W., Joyner, P. W., Almekinders, L. C. and Parekh, S. G. (2014). “Stress Fractures of the Foot and Ankle in Athletes.” Sports Health, 6(6), 481–491. https://pmc.ncbi.nlm.nih.gov/articles/PMC4212349/
Mountjoy, M. et al. (2023). “2023 International Olympic Committee’s consensus statement on Relative Energy Deficiency in Sport (REDs).” British Journal of Sports Medicine, 57, 1073–1097. https://doi.org/10.1136/bjsports-2023-106994
Welck, M. J. et al. (2024). “Stress fractures of the foot—current evidence on management.” Journal of Clinical Orthopaedics and Trauma. https://doi.org/10.1016/j.jcot.2024.102446