Gymnastics can be the most nail-biting event of any Olympics — but the worry isn't always over who'll win the gold. The first national study of gymnastics injuries, conducted by Nationwide Children's Hospital in Ohio, shows that gymnastics is among the most perilous sports for girls. Analyzing records of patients ages 6 to 17 who were treated in emergency rooms from 1990 to 2005, the study found that an average of 5 out of every 1,000 young gymnasts each year — about 27,000 — required medical attention for injuries ranging from sprains to nerve damage. Safer equipment and better training methods, however, may be making a difference. Injuries fell 25% over the 16-year period.