Bone stress injuries
Evidence: moderate
Bone stress injuries run from mild stress reaction to frank stress fracture, and the anatomical site decides how dangerous they are. The site classification and the link to low energy availability are well supported; the precise return-to-running timelines are guided more by experience than by trial.
Not medical advice
This is a general knowledge base, not medical or dietary advice. If you are injured, unwell or weighing up a supplement or a change to your diet, speak to a doctor, physiotherapist or registered dietitian who knows your situation.
A bone stress injury is what happens when bone is loaded repeatedly faster than it can remodel. The damage sits on a continuum, from a painful stress reaction with bone swelling but no fracture line, through to a visible stress fracture (Hoenig et al. 2022). Catching it at the reaction stage means a shorter, safer recovery than waiting for a fracture.
Site decides severity
Not all bone stress injuries are equal. Clinicians split them into high-risk and low-risk sites by how likely they are to heal badly, displace or progress to a complete fracture (bone stress injury reviews).
High-risk sites have a poor blood supply or sit under tension, so they are slow to heal and can become serious. They include the tension-side femoral neck, the anterior cortex of the tibia, the tarsal navicular, the proximal shaft of the fifth metatarsal (the Jones-fracture zone, not the readily-healing tuberosity at the very base), the medial malleolus and the talus (bone stress injury reviews). These need firm offloading, often a period non-weight-bearing, and medical supervision.
Low-risk sites heal more reliably with activity modification. They include the posteromedial tibia, the fibula, the calcaneus, the metatarsal shafts, the sacrum and the femoral shaft (bone stress injury reviews). These usually allow a graded return without surgery.
Front-of-shin and midfoot pain deserve respect
Deep, localised pain over the front edge of the shin or the top of the midfoot can signal a high-risk bone stress injury (anterior tibia or navicular). Both are slow to heal and prone to complications, so they need imaging and a clinician rather than a wait-and-see approach (bone stress injury reviews).
Risk factors
Training-load spikes are the mechanical trigger, the same too-much-too-soon pattern behind overuse injury in general (see running injuries). The biological side is just as important, and often more modifiable.
The largest modifiable driver is low energy availability, where intake does not cover the energy cost of training and daily living. A 2024 systematic review and meta-analysis found that athletes with low energy availability have impaired bone health, altered bone turnover and a higher rate of bone stress injuries (Gallant et al. 2024). This sits at the centre of Relative Energy Deficiency in Sport; see RED-S and body composition and weight. Low vitamin D and calcium intake compound the problem; see vitamin D and calcium.
Other risk factors include female sex, menstrual dysfunction and a prior bone stress injury. In female runners, the high-risk, trabecular-rich sites cluster with markers of low energy availability such as low bone mineral density, menstrual disturbance and restrictive eating (Tenforde et al. 2024). A previous bone stress injury, especially more than one, is a strong pointer to an underlying energy or bone-health problem worth investigating (Gallant et al. 2024). See the female runner.
A note on gear: a case series linked navicular stress injuries to carbon-plated ‘super-shoes’, but it had no denominator and cannot show cause (Tenforde et al. 2023). Treat it as a weak signal to introduce new stiff footwear gradually, not as proof of harm. See running shoes.
Diagnosis
MRI is the reference test. It detects bone marrow oedema before a fracture line appears, which allows earlier diagnosis and grading (Hoenig et al. 2022). Plain X-rays often look normal early and cannot rule the injury out. Grading systems such as Fredericson’s score the severity of oedema and cortical change, and a higher grade is associated with a longer return to sport, though the relationship is loose and the site matters more for the risk of complications (Hoenig et al. 2022).
Offloading and return
Management is graded offloading followed by a progressive return to loading, with the strictness set by the site. Low-risk injuries follow a symptom-guided return.
The bone-pain rule is stricter than for soft tissue
For bone stress injuries, the accepted pain target during, after and the day following loading is at or near 0 out of 10, unlike the mild discomfort tolerated in tendon or muscle rehab (Warden et al. 2021). Any return of localised bone pain means stepping back a level.
A typical low-risk return walks back through pain-free walking, then a walk-run progression, then continuous easy running, advancing only while the bone stays pain-free at each step (Warden et al. 2021). High-risk injuries follow the same logic but start later and progress more slowly, and high-grade tibial injuries can take four months or more before high-impact running resumes (Hoenig et al. 2022). Returning before the bone is ready risks turning a reaction into a fracture, so this is the injury where patience pays most.
Fixing the cause matters as much as healing the bone. A bone stress injury without a clear training spike should prompt a look at energy availability, vitamin D, calcium and, in women, menstrual function, or the next one follows. See RED-S.