"Oh, and for the anatomically correct?
Example : Humans only have one bone in their thights.
If you need more?
You'r on the wrong track my friend."

If you have TWO bones in the thigh (Like V1/2/3 - Judy), then you can use the "Thigh" bone to drive a side/side ERC morph fix, and the "buttock" bone to drive a "fore/aft" ERC morph fix.

That means you have a simple, automatic way to fix both side/side as well as fore/aft movement just by deciding which bone to use to move the leg.