I was skeptical at first, but it's worth every second as he keeps blowing the extent of his injuries completely out of proportion. He probably just tore his neck and back muscles.
That looked like a very serious neck injury. Jesus. That was moronic. I was surprised he was able to move after that and he "twitching" because his nerves are probably being SEVERED.
My favorite part of this is that at first he seems to be more or less okay, but the most weaselly of his friends gradually psyches him into a crippling injury.
I think I read somewhere that he turned out to be pretty much fine.