After that fascia post I thought you might actually start basing your argument on scientific fact. Lol
Miggy is internally rotating his left leg to turn his pelvis. He's not compressing his core. The hip internal rotators are contracting.
Go see the video in post 765 and specifically look at the part at 22:00 minutes about satellites. Then maybe you'll understand that it's not possible for the core to turn the pelvis. If the core is not anchored the movement is open chain and all that happens is the shoulders move closer to the pelvis, left to right, right to left. No turn.
BTW Fascia doesn't move musculature unless you mean that when the legs move the rest of the body follows because it's all encased in fascia/skin. The muscles are attached to bones with tendons. Break that connection and the bone won't move. Fascia or no fascia.
the back leg is the anchor. Why have you been reading on this forum lately that keeping the back heel anchored Is optimal. Very popular opinion yes?
to move 2 muscles together Fascia connects the two to create stretch and contraction. Muscles are the Fascial systems ‘Pedro’.