Motioning in football?

Backfield players can shift positions, including moving towards the line of scrimmage so long as come to a complete stop for a full second prior to the snap. After a shift, one back may then be in motion, but only parallel to or away from the scrimmage line at the time of the snap.

A team may shift any number of players into new positions, so long as they all come to a complete stop for a full second before the ball is snapped to start the play.

Motion occurs when a player is moving at the time of the snap. While different leagues have different rules regarding motion, most mandate that no more than one player may be in motion at the time of the snap, and that only players who start in "back" positions (running backs, fullbacks, quarterbacks, flankers, H-backs, etc.) may be in motion at the snap. Additionally, the NFL (professional), NCAA (college), and NFHSAA (high school) require that they must be moving laterally or backwards, and are not allowed to move towards the line of scrimmage. The Canadian Football League and the Arena Football League allow for motion towards the line of scrimmage.

To get a better perspective of the rule I would recommend going to NFL.com for professional rules or the NCAA website for college rules.... Those sites will help immensely.... Good luck....