Here is the Long and short of it: I make a model. I lower the model to lowest sub after zremeshing. I rig model with zspheres and use rotate to try and pose mesh.
mesh decides “oh fuch that shit!” and twists all the way down the mesh.
in the pictures i am rotating what would be the thigh bone and the the foot is twisting.
What is happening?
I can’t say it will solve your problem but I had the same and I made walk around for it.
I’ve added some spheres close to the area where the twist is happening and I’m correcting this twist by clicking and dragging this additional sphere. It.s possible to twist any zsphere this way. Try it out maybe it gonna be enough for you 
I faced twisting and squeezing of the mesh while making a bit more extreme posing.
Good luck
so I figured out what the fix is.
it comes down to the order the spheres are placed in.
for instance if you start at the hip and then drag a sphere to the tip of the toe then continue to add spheres to that chain to make the ankle and knee, when you start to pose the twisting begins to happen.
but if you start at the hip then make the knee then the ankle ect the twisting wont happen
