It was an important game against a big rival and the Garnets were gaining momentum. Caitlyn Ryland, then 20 years old, jumped up for a rebound. When she came down, her knee gave out under her. She fell to the court, crying in pain and fear.

Adrienne Shibles, head women's basketball coach at Swarthmore College in Pennsylvania, knew immediately what had happened. "After you see it enough, you just know what it is by the scream," said Shibles. "They go down, it's dramatic, and they scream."

Ryland had torn her anterior cruciate ligament (ACL) - a tough band of tissue stretching from the thighbone to the shinbone that stabilizes the knee joint. She would sit out the rest of the season, and undergo ACL reconstructive surgery followed by months of physical therapy to get back on her feet.

Ryland is not alone in her injury. Orthopaedists, coaches, and researchers all agree that anterior cruciate ligament tears among female athletes have grown to epidemic proportions. "ACL injuries are a huge problem with enormous financial and health consequences," says Elizabeth Arendt, MD, of the University of Minnesota in Minneapolis, where she serves as medical director of varsity athletics.

A slew of studies published during the past decade have shown that women are two to eight times more apt to rupture their ACL than men who play the same sports. The majority of these injuries occur in females aged 15 to 25, according to the American Academy of Orthopaedic Surgeons (AAOS.) Young women who play sports involving rapid pivoting, jumping, and sudden stops and starts (such as basketball, soccer, and volleyball) are particularly vulnerable to ACL injury.