Editor's note: This is a closer look at one of four player health and safety-related rules that are new to this NFL season, which begins Thursday.
NEW RULE: A ban of "peel-back" blocks inside the tackle-box area.
What the rule changes: A 15-yard penalty will be called on a player who is aligned in the tackle box when the ball is snapped, then moves to a position outside the box and initiates contact on the side and below the waist against an opponent if: (a) the blocker is moving toward his own end line; and (b) he approaches the opponent from behind or from the side.
How it would impact player health and safety: At least inside the tackle box, no player will be legally caught off guard with a low block that could cause serious injuries to his legs.
-- Bill Bradley, contributing editor