Why would you need a specific protocol for coming out of a sport concussion, though.
Because it is nigh on impossible to predict long-term effects of even a minor concussion. So the protocol is basically, a graduated return to activity, starting with some testing to assess, then light aerobic where patient's mobility, balance, coordination etc are all monitored closely along with cardiac performance and reactions.
Then stepped up a bit further. Monitored, tested etc.
Simply a way to assess whether or not the brain has fully recovered from the rattling it received. For player safety long term, the 'stand-down' period protects the player from being pushed back into action too early where further damage may occur.
While concussion is bad enough, the long-term effects of secondary concussion are quite frightening - a bruised brain, not fully recovered, can be re-injured without any significant external contact - normal movement of the head can re-injure in many situations.
So while the RTP protocol governs when a player can return to the field, it is just as much about the prevention of further, far more serious repercussions.
A player can play, without too much problem, before having fully recovered from a pulled hamstring for example, because if it goes again, it can still be repaired.
If the brain 'goes again' it can't. So you get the "Probably get 20 minutes out of him boss" when returning from a hammy, but a "Definately not" when recovering from a brain injury.
Was it Taylor Twerman, played for USA, had to stop playing because of repetitive concussion? Before the RTP protocol was developed? I know he was quite vocal about the need for it.