The Swim
The Swim Technique is a technique often used by pass rushers. The Swim gets its name from the fact that when properly executed the player has the appearance of a swimmer's upstroke.
In the swim the defender hits with the open hand the side of an opponents shoulder pads at about chest level. With the other hand the defender reaches out and over the shoulder of the blocker. The elbow is brought down to hook behind the defender. This technique is sometimes employed when a defender has an obvious size and/or strength advantage.
The Rip
The Rip Technique is usually employed by defenders and special teams players but especially by defensive linemen. The idea is to raise the arm close- handed backwards beneath the elbow and punch past the opponent's shoulder.
The Rip does not involve unnecessary contact. The object is not to hit the player full breath, rather to propel one's own torso beyond the shoulder and torso of the blocker. Then raising the elbow and coming backwards with it in a hooking motion further positioning oneself past the blocker.
Bull Rush
The Bull Rush Technique calls for the defender to get his hands up under the armpit area of the blocker and drive him back into the back field by vigorously pumping the legs and "bull rushing" into the backfield.