Also wood tends to channel the shock force thru skin and muscle, deep to the bones so a lot of times you have to commit to shattering bones to stop an aggressor. Whereas metal and plastics/polymers spread the force really well over the skin (read that as nerves) as well, therfore causing neuromuscular failure before the shattering of limb is required.
That's very interesting.
It also makes me want to choose a wooden bat.
-Blast