Stress fractures are some of the most common sports injuries. They are tiny breaks in the bone, usually caused by repetitive stress from activities like running. Although they can be quite painful, they usually heal themselves if rested for a few months.
Many different sports raise the risk of stress fractures. Activities that require running and jumping may cause fractures in the legs or feet. More than half of all adult and adolescent stress fractures occur in the lower leg bones. Of these, fractures of the tibia -- the long bone of our lower leg -- are the most common at about 24% of all stress fractures.
Other sports that require repetitive movements -- like pitching or rowing -- can result in stress fractures of the humerus (arm bone), but these are much more rare.
Stress fractures are much more likely to develop in people who have just started a new exercise or abruptly stepped up the intensity of their work out. When the muscles aren't conditioned, they tire easily and can't support and cushion the bones as well. Increased pressure is exerted directly on the bones, which can lead to a fracture.
Stress fractures seem to be more common in women. Other risk factors for stress fractures include: drinking more than10 alcoholic drinks a week, smoking, running more than 25 miles a week, osteoporosis, eating disorders and low levels of vitamin D.
Any anatomical abnormalities -- like fallen arches -- can distribute stress unequally through the feet and legs. This raises the risk of stress fractures. So can poor-quality equipment, like worn-out running shoes.
Unfortunately, stress fractures tend to recur. About 60% of people who have a stress fracture have had one previously.