Stress Fractures

DEFINITION

Stress fractures are tiny cracks in a bone. Stress fractures are caused by the repetitive application of force, often by overuse — such as repeatedly jumping up and down or running long distances. Stress fractures can also arise from normal use of a bone that’s been weakened by a condition such as osteoporosis.

Stress fractures are most common in the weight-bearing bones of the lower leg and foot. Track and field athletes are particularly susceptible to stress fractures, but anyone can experience a stress fracture. If you’re starting a new exercise program, for example, you may be at risk if you do too much too soon.

CAUSES

Stress fractures are caused by the repetitive application of a greater amount of force than the bones of your feet and lower legs normally bear. This force causes an imbalance between the resorption and growth of bone, both of which go on all the time. Repetitive force promotes the turnover of bone cells, but you add new bone cells when you’re at rest.

If your bones are subjected to unaccustomed force without enough time for recovery, you’ll resorb bone cells faster than you can replace them. As a result, you develop “bone fatigue.” Continued, repetitive force causes tiny cracks in fatigued bones. These cracks progress to become stress fractures.

SYMPTOMS

At first, the pain associated with a stress fracture may be barely noticeable, but it tends to worsen with time. The tenderness usually originates from a specific spot and decreases during rest. You also might experience some swelling around the painful area.

When to see a doctor

Contact your doctor if your pain becomes severe or persists even at rest.