A 19-year-old female college student reported bilateral anterior knee pain that she had had for at least 4 weeks. She denied any previous injury or precipitating event. The pain was exacerbated when she ascended and descended stairs, but she did not experience swelling or decreased range of motion in her knees. The pain did not compromise her daily activities and was absent at night. When she saw her physician, her sole activity was as a modern dancer; she danced several hours every day. She did not have a history of stress fracture, amenorrhea, or eating disorder.