First we contract a muscle. The instant the motion starts, even if just a finger, the forces we put into the ground suddenly change. Then the ground pushes back.
If we can put a lot of forces into the ground as we start our downswing, we create a tremendous brace to turn around and hit against.
Therefore the pivot we use will subsequently give us faster hands and more clubhead speed.
Focusing on the feet, and practicing the correct action can help us get the rest of the joints to act more efficiently as well. Many golfers fall back onto their rear foot as they hit the ball, resulting in a loss of power and a poor divot location behind the ball. When they can get their right foot moving into a better position through the strike, it almost automatically makes them shift their weight to the left side more completely.
Additionally, good footwork can help us reduce the risk of injury by lowering the amount of injurious forces acting on our spine as we hit the ball. Mike Austin had a unique move to drag the right foot in an arc around the posted left like a discus thrower or an infielder turning the double play.
Footwork drills should be used every day, done very slowly and correctly. When done in unison against the wall with the action of the hips and knees, a tremendous pivot motion can be developed.