Fantastic. That is much clearer. There are a few others I need clarified if you have the time.
What is internally rotating? The shoulders? The torso?
Rear upper arm (humerus). Similar feel to when you reach back with your throwing hand in the overhand throw motion. If you subscribe to the belief that "what loads, unloads" or, in this case, "what winds, unwinds", then the rear upper arm unwinds from internal rotation to external rotation. Which is what most of us do when we throw overhand.
I assume by "hinges" you mean that the knee flexes (moving the lower leg toward the back of the thigh).
Yes, but the player has to be careful not to over hinge. If a player over hinges they will have too steep of a swing gradient. Doing this is IMO just as bad as lunging.
I take lateral to mean from left to right, or right to left. I don't think this is what you mean. Rear shoulder dips (slightly)?
If you where to stand in place in the batter's box it would be back towards the catcher. Lateral tilt occurs virtually simultaneously when the upper torso turns so you can't see the lateral tilt taking place. It's really just one seamless move, which is how I prefer to teach it. Epstein's Torque Drill is IMO an excellent drill to teach this combination upper torso move. Sometimes I will break out the lateral tilt move if a player isn't understanding. Young players will sometimes get carried away and start bending at the waist too much. IMO the correct move is more in the shoulder complex and not the waist. IOW, you can stand facing a mirror and tilt your shoulders without bending at the waist.
The top hand (forearm) suplinates? Is the bottom hand (forearm) pronating then?
I do not see the front forearm pronating. The only group I'm aware of that teaches active pronation of the lead forearm is HI.com.
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