A stress fracture is a small crack in a bone from repetitive overload, common in runners and after a rapid increase in activity. Most heal with a period of offloading and graded return to activity, but some sites need closer attention.
A stress fracture is a small crack in a bone caused by repetitive loading outpacing the bone’s ability to repair. In the foot and ankle they most often affect the metatarsals, and also the heel, navicular and other bones. The usual trigger is a rapid increase in training or activity.
Assessment centres on localised bony tenderness and the activity history. Because early X-rays are frequently normal, MRI is often used to confirm the diagnosis. Identifying the specific bone matters, as some sites heal slowly and unpredictably.
Most stress fractures are managed non-surgically with offloading and a staged return to activity, alongside attention to the underlying cause — footwear, training load, and bone health including vitamin D, and, in athletes, energy availability. Higher-risk fractures (such as the navicular and fifth metatarsal base) and any fracture from minimal load warrant early specialist assessment and a bone health review.