Ok, Jim Riggins, Walter Payton, Joe Perry, Marshawn Lynch, Eric Dickerson, Mario Bates, Peyton Hillis, Bernard Pierece, Bilal Powell, take your pick - RB's putting their heads down to gain extra yards is an important part of the game.
This rule will not save anyone's brain, but it will lead to more passing, less sucecss and attempts running on short yardage, stupid & bad game changing calls with little grounds, RB's/WRs getting whistled when there was nothing they could have possibly done about it, and maybe even more RB's/WRs getting hurt when they fail to protect themselves because they are too worried about a penalty to put their head down. Talk about straw men.