Here is the little open-demo for this.
The player script I wrote for this is fast and bad... so I don't recomend using that part of the demo in your own game.
It should easily adapt to your player code... simply change the vertex numbers in the code for the chest collision, left leg collision and right leg collision to vertices from your players model.
I also suggest setting invisible to on in the player collisions three actions.
Newton-Collision-Demo
