Posted by: Jack Mankin (mrbatspeed@aol.com) on Sat May 29 19:48:17 2004

Hi JJA

Grc asked, “is jack's concept (of moving top hand toward the catcher while holding bottom hand stationary) torque, or is it something else (in scientific terms)?....

You stated, “The question of course is whether this push-pull action is what really happens in the swing. As you know, I believe there is no conclusive evidence that it does.”

It would be helpful to all if you addressed grc’s main point, “or is it something else (in scientific terms)?....” --- Let us use Sheffield’s pre-launch movements again as an example. He has the bat bouncing up and down about parallel to the ground. The bottom-hand (and knob) remains relatively stationary at the back-shoulder. Let us say the forearm (and top-hand) were pulled back toward the catcher by “scap loading.” Well before shoulder rotation is initiated, these forces applied at the handle caused the bat-head to be accelerated up and over the knob toward the launch position.

Grc’s question: Other than torque, what “something else (in scientific terms)” would account for this bat-head acceleration?

Jack Mankin