I remember reading on this bog a while

I remember reading on this bog a while back that there was a piece of software that modeled human bodies, and didn't let you rubberize the spines, making sure that everything was anatomically reasonable. I'm sorry that I can't seem to find it, do you know what I'm taking about? It's a thing right? Pls help! I want to make sure that I don't get bad habits and start contributing to the problem!

Can anybody help them with this?