TGM terms/definitions and statements (numbers/letters in parens are TGM reference numbers)
1. The Spine is the center of the swing which the shoulders rotate around (2-H).
The fog encountered in this thread can begin to be cleared only by firstcorrecting its root error. In that spirit:
The spine, specifically that point between-the-shoulders, is the center of the Pivot,i.e., the body's rotation. It is not the center of the swing(more correctly, the Stroke), which is the center of the Sweetspot's rotation.
Instead, per 2-H, the center of the Stroke is always the Left Shoulder,whether it is in motion (turning) or not. [That said, it is the Player's optionto utilize another Center for special applications, e.g., the Right Elbow in theBat Minor Basic Stroke (10-3-K).] When that Left Shoulder Center is in motion,i.e., in a Pivot Stroke, a consistent Stroke Center can beachieved only by maintaining a stationary Pivot Center.
As an example, think of the pendulum of a grandfather clock. The center of itsto-and-fro motion is always at the top of the pendulum, i.e., at its attachmentto the clock mechanism. You can move the clock from the foyer to the den, but thecenter of the pendulum's motion will remain at its attachment. If you wantto move the clock and still have the pendulum to pass through the same lowpoint in space as it did before you moved it, you are well-advised to leave theclock in the foyer and pivot it with great precision around its own centralaxis (which almost certainly will not be the pendulum attachment).
Linear Mode
