I'm not sure what you mean by side-to-side axis and front-to-back axis. Can you elaborate on that?
Not sure if i'm completely off on this. But what I mean is:
I remember somewhere reading about not using the hip flexors to raise the leg in shiko. That if that happens we have reverted to local muscle. Hip flexor action is almost exclusively F-B axis.
So the understanding is we are to use something else then to raise the leg in that portion of shiko. I am thinking of this as the body stabilized in the side-to-side axis.
Use of the hip flexors and ultimately bending the knee in squat position is the body aligned in a F-B sling/axis. I think this is the end of the stomp portion.
There must have been a moment of transition between these postural extremes. I think that transition is at that hand-turn-over moment. Could be wrong tho..What do you think?