YEAH YEAH YEAHS' star Karen O has radically changed her stage routine - because her wacky antics constantly leave her battered and bruised. The BANG hitmaker decided to tone down her aerobic choreography before she caused herself a serious injury. She says, "It was starting to wear me down to a little nub, having to reinvent the show every night. "The amount that I was injuring myself was escalating - cuts, bruises, chipped teeth, falling off the stage head-first. It was nuts. "It totally had control over me. I didn't have control over it."