A stress fracture is a small crack in a bone that forms as a result of repetitive force, usually due to overuse. Stress fractures are most common in the lower legs and feet, as these are not only the weight-bearing bones for our entire body, but also because they constantly and repeatedly absorb shock from activities such as running, jumping, or even just walking.
Anyone can develop a stress fracture, although they are more common in people who regularly undertake activities such as running or playing basketball. People are most likely to develop a stress fracture after they make a change to their routine e.g. buying new shoes, trying to run the same distance in a shorter amount of time. Certain conditions that weaken the bones, such as osteoporosis, also make a person more vulnerable to stress fractures.
Most stress fractures in the second or third metatarsals, which are the bones that run from the base of your toes back towards your legs. This is the part of your foot that is placed under the most stress when pushing our feet off against the ground. Stress fractures can also form in another bone in the feet called the navicular, as well as in the heel, ankle, and lower-leg bones.
Stress fractures are so subtle when they begin to form that nobody will ever notice them in their early stages. There are no major red flags that will signal you have a stress fracture, so in most cases, the condition is diagnosed after the patient has gradually suspected that they may have an undiagnosed condition. This suspicion comes from several ambiguous signs that can be easy to ignore at first, such as tenderness, swelling, and pain that sets in with physical activity, but diminishes while resting. In some cases, there may also be visible bruising, but this is not a particularly common symptom.
While it is possible for a doctor to diagnose a stress fracture with just a physical examination, most of the time a diagnosis will require the use of imaging. X-rays will not pick up on small fractures in their early stages, but can be used to identify fractures that have been forming for more than a few weeks. Alternatively, a bone scan can be used to identify smaller or multiple fractures. This is done by injecting you with a radiopharmaceutical, a radioactive drug that will cause any areas of bone that are healing to glow white in the scan. The radiation used does not pose any danger to most people, but is not suitable for pregnant or breastfeeding women. Finally, an MRI scan can use magnetic resonance to build up a high-quality image, and can therefore be used to identify fractures as early as possible.
Unfortunately, there’s not a whole lot you can do to treat a stress fracture. The most important thing is getting plenty of rest while it has time to heal. How long this takes will depend on the severity of your fracture, but it will usually mean you will be out of action for a few months. In the meantime, you can apply an ice pack for 15 minutes up to 4 times a day, and take calcium and Vitamin D supplements to promote bone healing. When your doctor advises, you can then begin to slowly resume physical activity.