Should Early VERTICAL be Early PERPENDICULAR Forearm?

[sclim]

I am surprised this question didn't occur to me earlier.

Like so many struggling senior swimmers I have been trying to make my peace with the limitation of my limited shoulder internal rotation which makes it impossible to achieve the magical Early Vertical Forearm catch which elite swimmers demonstrate and which looks so painful to emulate (and indeed it is painful to try!)

I am repeatedly reassured by the various coaches on this forum that strict EVF is unnecessary, and that "sort of" vertical is good enough. Indeed, looking at Terry's video demonstrations, he achieves his legendary efficiency and ease with a forearm that really is quite far from vertical.

Nevertheless, the theoretical principal is unavoidable that a moving paddle (i.e. the forearm) whose plane is not perpendicular to the direction of movement will allow fluid fluid to slip along the non-perpendicular plane. That is why the early Vertical Forearm early in the catch is advocated. So I try to get as vertical as I can, which is not very vertical when my elbow is ahead of my body, as it would be immediately following the spearing phase. Keeping the spear wide helps, as this position allows a more vertical angulation with the same degree of limited internal rotation.

However, when turning over the various options in my head to get more perpendicular positioning of the forearm, I suddenly realized that perpendicular does not necessarily mean vertical. That is to say, with my elbow at that same ahead-of-body position that allows only limited forearm verticality (with my limited shoulder rotation) when catching, I can still flex my elbow and achieve better perpendicularity if I allow the hand to swing in an arc that is more obliquely inward, i.e. toward the midline before I allow my whole arm to pull. With my lack of flexibility the hand actually reaches the midline before the forearm is perpendicular to the direction of travel. Seen from the front the angle of my forearm would not be vertical so much as oblique, way less than 45 degrees, in fact. I notice that in his videos Terry's forearm comes inward somewhat similarly, though not as much as I am describing, before his whole arm movement starts.

As my whole arm sweeps past my trunk and my elbow passes my head, I notice I have more shoulder rotation room, and my forearm can get more vertical, so indeed it can move to verticality during the stroke.

So is this a reasonable way of getting forearm perpendicularity in the catch before the whole arm is allowed to move (or from the other perspective, to anchor as the body is pulled past)?

I see that the hand will then trace out an exaggerated "hourglass" path that we are expressly told not to do, so maybe that is my answer. But I would like an explanation from an expert why that will not work so well, even though the "perpendicular" aspect of the forearm paddle in the catch is better achieved in this way (given one's limited shoulder rotation).