Kill Joint is literally a command to the creature. If X touches Y, then stop moving. It is something that activates only under specific circumstances. Adding a bone to stop two joints from rotating is simply the body you create.
Hmm... I don't entirely agree, but I do see your point. Still, I think it would provide some interesting options for creatures.
Yeah, you dont know how many times my creature fell on its ass and thne that was the only thing it ever did no matter how many generations I wait
instead of kill the brain why not do something to discourage the AI from making those join to touch the ground?
like a secondary objective?
weaken the bone ? up to destroying it if it get hit too many time?