Female student athletes who have abnormal menstrual cycles and eating behaviors are more likely to develop over-use injuries, a recent study found.

Stress-related leg injuries and fractures are more prominent in female students, a phenomenon attributed to eating disorders, bone demineralization and irregular periods, according to a study published in the September edition of the American Journal of Sports Medicine.

At the head of the study was Mark Reinking, a physical therapy faculty member at Saint Louis University, who has been interested in over-use injuries for 15 years.

In his study, Reinking looked at the eating behaviors of athletes and non-athletes without knowing their caloric intake. Reinking used the Female Athlete Screening Tool (FAST), a survey of 33 questions presented to the athlete, which helped him determine how at risk a female athlete was for developing an eating disorder.

"Five of the 76 student athletes studied did develop stress fractures," Reinking said. "And they did show more abnormal scores on the FAST and had a lower bone density."

The most common over-use injury seen in the study was medial tibial stress syndrome (MTSS), an injury that causes pain along the inside of the calf, Reinking said.

While Reinking's study did not measure estrogen, other researchers believe there is a link between bone density and estrogen.

Evan Pattishall, clinical director at University Health Services (UHS), said female athletes are more susceptible to developing stress fractures because they are more likely to decrease their caloric intake. When combined with exercise, this reduces estrogen and causes bone loss.

At Penn State, cases of stress fractures are rare, Pattishall said.

"We see some but not a significant amount, but I don't think we have the population of students that are really restricting their diet that much," said Pattishall.

Dr. John Deitch, an orthopedist at Penn State Orthopaedics, said he attributes leg injuries to the "Female Athlete Triad," a well-known phenomenon in the athletic world.

The three components that make up the Female Athlete Triad are "disordered eating, menstrual dysfunction and bone demineralization," Reinking said.

To avoid over-use injuries, Deitch suggests that student athletes get adequate rest, wear appropriate shoes and use proper equipment.

"Try to maintain a good, well-balanced diet including dairy and vegetables," Deitch said.

Periods of active rest, such as cross-training, can also help prevent over-use injuries, Deitch said.

"Changing the amount of activity and load of activity keeps the body fresh," he added.

Pattishall suggests that students "maintain a reasonable caloric intact and a reasonable exercise program without significantly increasing their exercise program."

Additionally, when students decide to take their workout to a new level, they should gradually work up to it, said Pattishall.

While eating disorders are not always to blame, Deitch said, "Friends should watch out for friends, teammates should watch out for teammates."