Most exercise-related aches and pains are fleeting and disappear with time or improved fitness. But a nagging, persistent sore spot on your leg or foot may indicate a stress fracture, or tiny bone crack. While less drastic than typical broken bones, a stress fracture can be painful, limit your activity, progress to a more serious fracture or warn of other problems such as low bone density or osteoporosis.
These bone cracks may start out as swollen, tender spots that become more painful with activity. Pain increases over time, occurs early in your workouts and persists even at rest. X-rays may be used to diagnose stress fractures, but X-rays aren’t always reliable. Your doctor may suggest a CT scan, MRI or bone density test as well.
Stress fractures occur when repetitive force, like your foot striking the ground while running, overtaxes the bone, causing it to crack. Most fractures occur in weight-bearing bones like the tibia and fibula of the lower leg and metatarsals (long bones) and the heels. They fall into one of two categories:
- Fatigue fractures occur when normal bone is subjected to the repetitive stress of high-impact activities like running or jumping. When the muscles become too fatigued to absorb the stress, they transfer it to the bones.
- Insufficiency fractures occur when bones are weakened because of a mineral deficiency, low bone density or osteoporosis. A bone that cracks with routine or normal activity, such as walking, is often an insufficiency fracture. Your doctor will conduct tests to determine why your bones are weak.
You may be at increased risk for stress fractures if you:
- have osteoporosis or other conditions that lead to decreased bone density
- have abnormal or absent periods (like women who are approaching or past menopause or are highly competitive athletes)
- suddenly increase the amount or intensity of your physical activity
- have flat feet or high, rigid arches
- participate in high-impact sports such as tennis, running, jumping, gymnastics, tennis and basketball
It takes six to eight weeks for a stress fracture to heal, during which time you’ll need to stop the activity that caused the fracture. Apply ice packs to the injured area and take acetaminophen for pain. Avoid strength-building exercises or excessive stretching of adjacent muscles. Don’t train on unusually soft or uneven terrain while injured. Your doctor may suggest crutches, braces or shoe inserts to take stress off your bone while it heals.