A stress fracture is a crack in any one of your bones, and it is a true fracture, meaning that your bone is actually “broken”, but is not the result of a single traumatic event or injury. Stress fractures commonly occur after repetitive strain and overuse of one particular area of the body. In the foot, the metatarsal bones, especially the 2nd are the most vulnerable. Stress fractures are common in runners.
Each bone in your body is lined with a sleeve of tissue called the “periosteum” which is filled with nerves and blood vessels. As the strain through a given bone increases, you may have pain and swelling over that area, indicating a stress reaction is beginning. Pain that does not warm up and go away with activity is often a sign that there is a problem more than just muscle soreness/stiffness. The pain you feel is from those little nerves/vessels sending a signal to you that there is a problem developing. This is a sign to reduce the intensity and frequency of your workouts, and to use ice and rest. If the symptoms reduce and the pain eventually goes away, you can gradually resume your workouts and hopefully your stress reaction will not progress to a fracture.
If you do not heed the initial warning symptoms of pain and swelling, the stresses will continue and you may develop a full-blown stress fracture, where the bone cracks, unable to resist the increasing force. There is focal pain/swelling over a given area, there may or may not be bruising, and you will have difficulty walking without pain.
Diagnosis will include a thorough examination by your physician, Xrays, and possibly a more detailed imaging study such as a bone scan or MRI. These advanced imaging techniques may be used if there is a high suspicion of a stress fracture despite normal Xrays. Not all stress fractures will be noticeable on regular Xrays.
If you are diagnosed with a stress fracture, the treatment involves time off of your given sport, often wearing a protective boot or shoe, and potentially even no weight on your foot with the use of crutches depending on the bone involved. It is critical to follow the recommendations of your physician carefully, to allow for proper healing and the quickest return to your sport or other daily activities.
Ways to prevent stress fractures and other overuse injuries include gradual increases in intensity/distance/weight when exercising. Your body is well-adapted to respond to these healthy stresses when given appropriate time. Wearing proper shoegear and using athletic equipment that is proportional and fit to your body structure is also important. Taking the time to warm up and stretch both before and after activity is helpful. I have also found that cross-training, which is doing different activities throughout the week, will use different areas of your body and reduce stress on any one body part/bone.
Remember, any foot pain that does not respond to a few days of rest and icing should be evaluated by your podiatrist. An early and thorough evaluation may prevent worsening of your problem, before it progresses to a fracture or other serious injury.