There's no denying that football players at all levels are subject to concussions. Those who watched the Washington Redskins and San Francisco 49ers face off on Sunday saw a dramatic example of head trauma's terrifying effects in real time.
Towards the end of the second half, Redskins rookie Montae Nicholson took a direct hit to the head that sent his helmet flying and left him convulsing on the field for seconds after the end of the play.
Here's another look:
Even so, he was medically cleared during halftime and returned to the game 30 minutes later.
The incident prompted a heated debate among fans who disagreed on the severity of the injury and whether Nicholson should been put back in.
In light of recent research that found widespread degenerative brain disease among deceased NFL players, incidents like this are even scarier.
What do you think?