The problem is that without a script and animation to lock your feet, shoes or hands the animation overrider you are wearing will most likely animate those body parts. This can be easily observed with primitive sculpted feet or shoes since the lower leg will not always be in-line with the feet as it should.
From what I could determine, the way this would work is using a script that triggers an animation which locks your ankle or wrists into position so that when the rest of your body moves, the shoes or primitive hands you are wearing appear locked.
The following set of scripts and animations are meant to lock-down body parts. However, the most sensible solution would be to wear sculpted heels and hands on different attachment points that do no flex.
For example:
L Forearm
and R Forearm
respectively.L Lower Leg
and R Lower Leg
respectively.the obvious advantage is that you lower your script count (and script time) considerably.