9-3-5b The offensive blocker is between the runner and the potential tackler. The defender pushes the blocker from behind above the waist, then continues to pursue and make the tackle. The contact by the defender on the blocker is legal. It is also legal to use hands on the back of an opponent when the ball is loose and the player may legally recover it. It is legal for defensive players to contact opponents in the back above the waist. Players of either team who legally attempt to recover or catch a loose ball they may legally possess may also block an opponent in the back above the waist.