Stress buster.

From ballerinas to football players, athletes may ignore pain to avoid missing out on performances or game time. But those pains are often a sign of an impending stress fracture, or a crack that occurs in the bone because of repeated stress or overuse. A stress fracture can sideline an athlete for a whole season. A new device being developed by researchers at Purdue University and the University of Toledo promises to detect a potential stress fracture--so athletes know when to take it easy.

As a ballerina repeatedly leaps into the air and lands on her toes, pressure from hitting the floor can cause the dancer's legs to develop tiny "microcracks." Any one microcrack alone is not enough to cause a stress fracture. But if the athlete fails to rest and allow time for the tiny cracks to heal, multiple microcracks can accumulate. If the bone develops too many cracks, it can suddenly splinter into a stress fracture.

In order to help athletes avoid a painful break, the new device uses technology similar to that used for measuring the vibrations caused by an earthquake. A Band-Aid-like sensor attaches to the athlete's skin. There, it can detect the vibrations that travel through the athlete's bone as each microcrack forms. The device would alert the wearer to the looming danger of a potential stress fracture.

The researchers plan to equip students on several sports teams with the device early next year.