In the February 2002 issue of Bow & Arrow Hunting, Bernie Pellerite has a column discussing grips. It explains all of them and goes very in depth on the low wrist grip (including some great pictures).

If a low wrist grip is done properly, there should be very little contact between the bow and hand. You are essentially heeling the bow all the time with the base of the thumb. This is creating as close to a "bone to bow" contact as you can and eliminates using most of those pesky muscles. The more of these that are eliminated, the steadier the sight picture. The low wrist grip if done properly should be quite tourque free.

Where people get into trouble is by contacting the bow from the webbing to the base of the palm while crossing the lifeline on the hand. This is actually more of a neutral or medium wrist grip and can be very prone to tourque.

Hope this helps!!!