The push-pull principle is a basic concept of physical mechanics, and is very important in some wrestling and grappling techniques. In a nutshell, it is the application of applying two forces at different points against your opponent’s body, each being exerted in opposite directions. (One pushing, the other pulling.)
A technique the illustrates this principle well is the double leg take down. (sometimes resembling a tackle) As you shoot in, you grab your opponent’s legs behind the knees. You then pull his knees toward you, forcing them to buckle a bit. This is the “pull.” At the same time, you exert force to his upper body, pushing him backwards. This is the ‘push.” Combined, this two way motion works better than either alone.
Pushing and pulling at the same time makes it easier to rotate your opponent’s body. (I show a different version of the push-pull principle in my Chokes & Sleeper Holds DVD when I teach an effective way to get into the rear naked choke when your attacker is in front of you.) When we are executing the double leg take down, the rotation is the act of rotating his body by toppling it toward the ground. The reason he doesn’t completely flip around is that he hits the ground first and it stops his rotation.
Of course there is more to an effective double leg take down than just the push-pull principle. You need to have a good shoot, have your knees bent during your penetrating step, grab your opponent low enough, proper drive forward, driving your shoulder properly into the lower stomach or pelvis region, and so on.
But for purposes here, I want you to remember the push pull principle and how you can use it to unbalance a person and move into a better position yourself. If you properly secure and pull your opponent’s legs as you push and exert enough force to move his center of gravity back a couple of inches, there really isn’t anywhere for your opponent to go except to topple over backwards to the ground. The push-pull principle is simple, but when needed, it’s important.