M - Do you 'feel' as if the trail hand stays on top of the lead hand through impact?
P - I don't understand this one.
With IMA and inertial pushing I feel the trail hand below the lead hand - 'racing around'. If I 'retain' then the 'feeling' is that of the trail hand staying more on top and leading to a more pronounced horizontal release. I feel that Petearm asked you the same kind of question.
P - This will prove to be an interesting one to model. You'll have to do some trial and error on the dynamics of release. What I think happens is that the rotation of the 'Keystone' is accelerated by the energy transfer from the arrested lower body shift/rotation. This extra energy overcomes the retaining force. As the club comes out COAM decelerates the hands and arms more and ... you wind up with an cascade forcing the club out to impact.
I am not sure but think you are implying a 3D model. I was modestly thinking of trying to model it for now in two dimensions as per my diagram. I am however drifting towards 3D modelling and going to learn first more about developing/solving/plotting complicated Lagrangian equations. It is going to be tough going, from 2 to 3 dimensions can multiply the # of DV-equations by 3. If not practical at least it will keep my grey cells occupied.
I don't know if I quite agree with you on the matter of energy transfer. I feel, for now, it to be quite the opposite, not an energy transfer through ‘arresting' the lower body move but on the contrary through active rotation of lower body starting after the vertical drop. The sudden transition from 'vertical' drop to horizontal 'tucking' gives a sudden acceleration to the club head. I might be wrong, I still lack a good feel for Bertholy's method.
