I have (and still use) the door jamb for various simulations. If you give me the page you saw this on I will clarify. I do use this reference in my "tool tips" (see below). You can use a door jamb at ground level to simulate impact. Pretend the bottom of the door jamb is the ball. Using a golf club, set the club head up against the jamb, just inside your front foot. You can them unwind your hips a little (like turning through impact), pushing up against the jamb to simulate impact. This sends a great imprint to your brain. It kind of maps how all the body parts are (should be) working together, turning, trapping the ball at impact. Just keep repeating this impact position and hold impact a few seconds, and surprisingly, you'll start to feel impact position during your swing. It is like your body is now familiar with how you want impact to feel like, because you've been practicing it. With practice, the body will do it! * Nothing "happens" in this position. It is a dynamic position... kind of a moment where things come together as you are rotating and accelerating around to the finish.
Move Less ... Get Good! DUPLESSISGOLF