I don't think this fan hurt himself, but either way, his misadventure was hilarious. A fan sitting on the baseline at the Grizzlies-Clippers game raised his arms, began spinning a towel over his head like a helicopter, and then suddenly pulled up lame, grabbing his elbow. It looks like a serious, towel-induced injury.
The best part about it all is the fan doing it all by himself. Everyone else is stoic, except for overzealous towel-waver. And soon we see why.
The context: There was a missed alley-oop by the Grizzlies, and the fan was celebrating too soon. Acting hurt seems to be his way of playing it off. Never, ever wave the towel until it's absolutely necessary, friends.