thank you very much.. i think this is called a reverse foot IK rig.. its pretty standard and most simple setup for any kind of leg rig.. from here on we can add a lot more bones and controllers to get it to do exactly what we want
Welcome very much! I still use that same rig today... it's good stuff. I've never come across a situation where I have to get much more complicated than this, although sometimes I blend IK/FK in the rig. Of course, I always animate with shoes on, so I've never had to play with toes or the more complex bend and flex of bare feet.