But several organizations have made it clear that cheerleading accounts for a disproportionate number of major injuries in youth or college athletics. In 2005, the National Collegiate Athletic Association’s Catastrophic Injury Insurance Program found that 25 percent of the money spent on claims for student-athletes since 1998 resulted from cheerleading. That made it second only to football. The ratio of cheerleaders to football players is about 12 to 100.

After a high-profile injury a year ago to a Southern Illinois cheerleader — her fall from a pyramid was caught on video and broadcast widely — the N.C.A.A. cracked down with new restrictions. The guidelines mandated the use of mats when cheerleaders perform more challenging stunts, and most significantly, college coaches now must take a safety certification course if they want catastrophic insurance coverage.

Inadequate training of coaches is the most frequently cited cause of injuries. Inexperienced coaches will have squads try complex stunts without following accepted step-by-step progressions to acquire the skills required to safely attempt the trick. The coaches association certification, which costs $75 and is available to coaches of all levels, details proper techniques and procedures.

While the association has vigorously pushed numerous safety initiatives, it has only so much influence over the unconfined cheerleading community. There are more than 75 cheerleading organizations, varying from state to state and region to region, all with their own regulations and competitions.

Even in high school cheerleading, there is no uniformity of regulations nationwide and little statewide control. Many teams routinely do stunts that would be banned in the N.C.A.A. This is largely because most states do not consider cheerleading a sport, so it is not under the aegis of a powerful state athletic association. Instead, cheerleading is labeled an activity, which often means it is regulated by the same state education groups that govern the chess, debate and French clubs.

“Some states don’t want to touch cheerleading with a 10-foot pole,” said Susan Loomis, the spirit coordinator of the National Federation of State High School Associations who also oversees a coaches education program. “Fifteen to 18 states actually regulate cheerleading. But many, many schools do not follow our rulebook and their coaches are not skilled — sometimes with disastrous results.”