My friend was longboarding down a hill and when you hit the grass you jump off the board. Except when he hit the grass, he hit a rock. Busted open his knee, had to get multiple staples in his knee. Like legit staples x.x. Right as he gets his cast off he plays TACKLE FOOTBALL when we got to go outside durring studyhall on everyother Friday. Busts open the cut again, has to get more staples in his knee. Now he has to wear this wierd net thing on his leg it keep his pad in place. Moral of the Story, jump off on time, and if you don't, don't land on a rock. Or just be a lazy ass like 'ol happycat and lurk on a forum all day.