The swim move in football is a technique used by defensive line players and linebackers to get away from the offensive line's blocking and rush the quarterback. The move is called a swim because the movement resembles a swimmer's stroke. The technique is usually used by players when they are being blocked by a shorter or weaker player.
For a player to do a good swim move, it is necessary for him to have good hand-feet coordination, as he will move both at the same time. After the snap and with the eminence of being blocked, a defensive player will start to move his feet in jab steps, as a way to confuse and freeze the blocker, while using the arm to the side he is swimming, to reach and push the offensive lineman's shoulder or upper chest area. The push will leave the blocker off-balance, making it easier for the player to get through him. The rest of the movement is done by lightly passing the other arm over the defender's shoulder, and the body by the side, leaving the offensive lineman completely behind.