Pay careful attention to exactly what Gramm wrote, "go STRAIGHT down". When squatting to duck avoid dropping your head and shoulders forward or even bending forward at the waist -- go down with a straight AND VERTICAL back when practicing.

There will be times when you lean or whatever but most of your squats should keep your shoulders directly over your hips.

Most people can do this easily for a few inches or more, but as the squat deepens then lean further and further forward -- sit down in the butt and say vertical.

RELAX to go down (you cannot pull yourself the floor) and Power Up.

Throughout all of this you must maintain foot placement and good balance.

--
Herb