Forty-five minutes after she put on her new toning shoes, and just a few days before her vacation to Mexico, Sandra Yellin stepped awkwardly and felt a sharp pain in her left foot as she made the short walk from her office desk to the copier. A trip to the emergency room confirmed the worst: the medical-office manager from Westchester, N.Y., and my former patient, had broken her fifth metatarsal, the bone on the outer edge of her foot. Instructed to stay off her feet for at least two weeks, she canceled her long-awaited trip.

About 3.5 million children ages 14 and under, are treated for sports-related injuries each year, and half may be preventable, according to Safe Kids USA.