I'm not so sure what to call this.. I call him Mr. Egg.
But this can help you with more realistic walking animations
I got inspired by this image here
Check it out!
Download here: http://www.mediafire.com/download/1nqnv72xydkvgvn/Mannequin+Rig+Mark+II.zip
If you happen to use this.. no need to credit me, remember that