Cheerleader Basketball Girls, Khimki Club, Moscow, Russia

Dangers of cheerleading
The risk of cheerleading was highlighted when Kristi Yamaoka, a cheerleader for Southern Illinois University, suffered from a fractured vertebra after she hit her head after falling from a human pyramid. She also suffered from a concussion, and a bruised lung. The fall occurred when Yamaoka lost her balance during a basketball game between Southern Illinois University and Bradley University at the Savvis Center in St. Louis on March 5, 2006. The fall gained "national attention", because Yamaoka continued to perform from a stretcher as she was moved away from the game. Yamaoka has since made a full recovery.
The accident caused the Missouri Valley Conference to ban its member schools from allowing cheerleaders to be "launched or tossed and from taking part in formations higher than two levels" for one week during a women's basketball conference tournament, and also resulted in a recommendation by the NCAA that conferences and tournaments do not allow pyramids two and one half levels high or higher, and a stunt known as basket tosses, during the rest of the men's and women's basketball season. On July 11, 2006, the bans were made permanent by the AACCA rules committee:
The committee unanimously voted for sweeping revisions to cheerleading safety rules, the most major of which restricts specific upper-level skills during basketball games. Basket tosses, 2½ high pyramids, one-arm stunts, stunts that involve twisting or flipping, and twisting tumbling skills may only be performed during halftime and post-game on a matted surface and are prohibited during game play or time-outs.