If you've ever seen an Arena Football game, they put walls up to keep the fans off the field and create a pretty sudden "out of bounds" area for the players.
And there is a reason that you are told not to lean in to the field of play.
But there's always at least one moronic fan who ignores that warning and does exactly what they should not do.
This guy, in Spokane, Washington at the Spokane Shock vs. Arizona Wranglers game...well, he probably won't make that mistake again.
Look what happens to the Shock fan, who gets the Shock of his life on an overthrown pass. He doesn't get bumped, he gets plowed by the wide receiver trying to make the catch.
And yeah, it really does look like it hurt.