whats the deal with pressure points and mma?

some effective things i can think of would be digging into sensitive areas with your fingers like behind the knee arm pit elbow collar wrist i think doing that would be incredibly helpful when on the ground trying to get out of some kind of hold.

what about elbowing some one then digging in like hitting them in the ribs then putting your weight on it and wiggling it till it tears a muscle between the ribs.

what about the traps as well a very sensitive area and repeated hammer blows could easily tear the muscle break the collar bone and knock a person out.

are such things not done because they are not allowed, because people just dont think of such things, or are people actually specifically attacking pressure points and its just generally agreed that its not very effective?

I think its not really that effective. Pretty unsportsmanlike as well. Small joint Manipulation is not allowed...

Why not just break fingers off , its kind of silly that they don't let that happen :) !

I think its just generally agreed that its not very effective, you take more out of your opponent when you hit his head or his body than anything else.
You can hit your opponents' arm for 30 minutes, he still won't lose. Look at Winky Wright.

Small joint and nerve manipulation are barred from the rules.

Small joint and nerve manipulation are barred from the rules.Why is that? I mean, you can pretty much kill someone with strikes and the various submissions.