A stress fracture occurs when a bone cannot respond adequately to the forces placed upon it. Normally, bones are constantly rebuilding themselves, reacting to the stresses placed on them, and producing new bone in areas of bone that have broken down. If this process becomes unbalanced, micro cracks, or “stress fractures,” can develop. A stress fracture causes a weak spot in the bone which may develop into a complete fracture.
 
The most common cause of stress fractures is overtraining. Stress fractures usually occur in athletes or military recruits. Training errors such as sudden increases in training intensity or duration can lead to stress fractures. Other changes in training regimens can also lead to stress fractures, including changes in shoe wear, running or training surface, and workout routines.
 
The main symptom of a stress fracture is pain. Typically, pain due to stress fractures gets worse with activity and is relieved by rest. There usually is a history of a recent increase in training intensity or duration. Sometimes there can also be direct tenderness on the bone. For deeper bones, pain can be elicited indirectly, such as with movement of the bone or use of the bone.
 
Because of the risk that a stress fracture may progress to a complete fracture, it is important to make an accurate diagnosis. It is recommended that an athlete consult a physician if there is pain with activity that does not improve with three to seven days of rest. After taking a history and performing a physical examination, the doctor will usually order an x-ray of the affected body part. Unfortunately, many stress fractures do not show up clearly on regular x-rays, and it is sometimes necessary to get further tests, such as a bone scan or an MRI.
 
For most stress fractures, the treatment is simply rest from activities that cause pain. In lower extremity stress fractures, cross-training with lower impact exercises such as swimming, biking, and elliptical trainer is allowed. In some cases, reducing the mileage or training on a softer surface is all that is needed. It is also important to maximize the body’s overall ability to produce healthy bone. This means proper rest, sleep, and an adequate diet which includes appropriate amounts of protein, calcium, vitamin D, and calories.
 
Hormonal issues are especially important in females. Overtraining and inadequate caloric intake can result in menstrual irregularities such as lack of periods. These hormonal imbalances result in a predisposition to stress fractures and difficulty in healing already established stress fractures.
 
In summary, it is important that stress fractures are properly recognized and treated. Ideally, it would be best to prevent stress fractures from developing in the first place. Proper nutrition and gradual and intelligent progression of physical activities are the most important factors for preventing stress fractures. One guideline is the “rule of tens”, which means that the intensity or duration of any physical activity should increase by no more than 10 % per week..