Simply put, stress fractures are small cracks in the surface of the bone. They occur most frequently in the foot and on the two lower bones of the leg. In fact, 95% of stress fractures are on these bones, since there is more stress on the lower extremities while running than on the other bones of the body.
Stress fractures of the foot became best known among military recruits. Relatively out of shape when they got to boot camp, many recruits developed stress fractures of the metatarsal bones (the 5 long thin bones of the foot between the toes and the ankle) when they suddenly had to walk or run twenty miles a day. At Choate, stress fractures are most common in autumn, when students run many miles in training for field hockey, soccer or cross-country after relatively inactive summers. Running on hard surfaces, what Dr. Southmayd calls the “battering ram effect,” causes a weakened bone to crack superficially. Bones can often be weaker from poor mineralization caused by nutritional deficiencies.
The stress fractures on the leg itself are usually mid shaft of the fibula (thin outside bone of your lower leg) or mid shaft (or higher) of the tibia (the large strong bone of your lower leg), usually on the inside side (medial). Sometimes it is hard to differentiate a stress fracture from a shin splint. A stress fracture is a fracture that hurts in a specific spot, not over a diffuse area as is the case with shin splints. Sometimes they cause swelling.
X-rays are not helpful in the first couple of weeks, since the fracture is too small to be seen on the x-ray and there has not been enough healing (callus formation of new bone). For a more immediate definitive diagnosis, a bone scan (injecting a radio isotope into the blood stream, which flows to the site of a healing process and “lights up” an x-ray (the scan) of that spot) may be helpful. Usually, however, the bone scan is not necessary. Pain prevents running or makes it difficult, and the only way to heal a stress fracture is to rest for four to six weeks. After the healing process, a gradual return to sports is beneficial.
At times, the patient will feel better walking around in a “walking cast,” a strap-on boot, for comfort and support. All four of the “boots” that we have in stock at the Health Center are currently being used on campus! The injured athlete should definitely work on cardiovascular and muscle conditioning during the healing process to facilitate the return after the rest period. Swimming and the elliptical machines are usually the best.
Source: Sports Health, The Complete Book of Athletic Injuries. William Southmayd, M.D. and Marshall Hoffman, GP Putnam.
