Publishing in the April J of Pediatrics,Ohio State researchers analyzed 3,000 male and female injury cases across a range of sports such as soccer, volleyball, gymnastics, and lacrosse.
The highest rate of overuse injuries occurred in girls track, followed by girls field hockey, and girls lacrosse. For boys, most injuries came in swimming and diving.
Intensity of of athletics has increased over the past decade, with some HS students spending 18 hours a week in such activities, often in more than one sport.
The lower leg is the most common site of overuse, followed by the knee and then the shoulder.
Overuse injuries account for more than twice as many visits to sports doctors than trauma.
Girls (and boys, of course) are developing bones at the greatest rate--they need proper calcium and Vitamin D.
Cross-training in other sports is recommended. So the athlete is not repeating the same motions all the time. Warmups are good. And learning proper form.