What is a stress fracture?

A stress fracture occurs when an abnormal amount of stress is placed on a normal bone, such as when a runner rapidly increases his mileage rather than gradually progressing to longer distances.

Other types of stress fractures can occur in the spine, and are often seen in athletes who participate in sports such as gymnastics, cheerleading and football.

A stress fracture is a hairline crack in a bone. In some cases, the crack may be so small that it is not visible on an X-ray.

Stress fractures are usually caused by repeated stress on a bone rather than by a specific injury. They can occur in any bone that repeatedly bears weight. For instance, stress fractures in the small bones of the foot are common during intensive training for sports that involve lots of running or jumping. A stress fracture is also more likely to occur in a bone that is not accustomed to or conditioned for a particular activity, such as when a person starts a new sport.

The most common symptom of a stress fracture is persistent pain at the site of the fracture. Pain may improve temporarily during exercise but gets increasingly worse after each exercise session.

If the activity that caused the stress fracture is stopped, the bone will heal and symptoms will go away. The activity can then be resumed gradually until the bone becomes conditioned to the repeated movements.

A stress fracture occurs from overuse and develops over time due to repeated trauma. Stress fractures occur most often in athletes and in the lower leg and foot. (This answer provided for NATA by the Weber State University Athletic Training Education Program.)

Stress fractures are bone injuries that affect less than 1% of the population. They are exacerbated by running, walking, marching, or jumping. These overuse injuries are the result of repeated tensile or compressive stresses on bones, most commonly the long bones of the leg. Certain factors such as previous injuries, acute increase in activity, prolonged glucocorticoid use, weakened bones and female gender increase the risk of stress fractures. Interventions that have been associated with improving outcomes in patients with stress fractures are use of shock absorbing inserts, calcium/vitamin D supplementation, and training regimen modifications.

Let me give you an analogy of a stress fracture. A stress fracture is like a "coat hanger" that you bend a certain number of times and it breaks. The bones are very similar, except for the fact that you go to bed at night and the bones can heal. So what happens with a stress fracture, there is force on the bone and the bones do not have time to heal. They typically occur in specific locations. They occur in the second or third metatarsals of the foot, in the tibia or in the hip area. It is more common with people who have  osteoporosis or weak bones or individuals who have been at bedrest for a prolonged period of time (regardless of age).