I do pullovers with weight plates placed on my forearms.
When doing pullovers like this lay on a bench, your forearms are in the same position as a skullcrusher. But you don't straighten the forearm and you let the plate move behind the head and down. this more closely simulates a pullover machine.
I don't like the stress a dumbell with a straigtened arm places on the shoulder and triceps. So doing a pullover with plates is a ideal.
As for expanding the ribcage, I really don't think so. Though this idea could be attributed to the stimulation to the outer pec that you can get from pullovers.
Personally I do them for serratus deveolpment and isolating the upper lat.
Btw, I invented this alternative take on the pullover. And it is called the I pullover (I stands for Indie/Isolation pullover)
<message edited by indie on 26 June 2008 02:53>