Posted by: Jack Mankin (MrBatspeed@aol.com) on Sun May 19 13:17:53 2002

>>> What is the back/top hand doing just prior to and during the bat's movement thru the hitting zone? <<<

Hi MM

One of the key differences between linear and rotational mechanics is: – what is driving the hands as the bat accelerates through the contact zone? For this discussion let us assume the pitch to be in the center 2/3 of the plate. --- With good rotational mechanics the shoulders are still rotating through contact. The lead-shoulder will have rotated to a point where it is now pulling back toward the catcher. So, at contact, the lead-shoulder is pulling the lead-hand back (the “hook” effect).

As the lead-shoulder pulls back toward the catcher, the back-shoulder is rotating around toward the pitcher. Just before contact, the back-arm will have rotated down to horizontal to form the “L” position. Therefore, back-shoulder rotation (not arm extension) is driving the top-hand around toward the pitcher. – One hand pulling back as the other is driven forward, applies a great amount of torque to the bat.

Rotational mechanics generate a great amount of bat speed from constantly applying a combination of these two forces (circular hand-path (chp) & torque) from initiation to contact. – Shoulder rotation is driven by the body’s larger muscle groups. I stated earlier in the post that: “With good rotational mechanics the shoulders are still rotating through contact.” But, due to poor linkage and bat initiation, most batters complete shoulder rotation with the bat 30 to 80 degrees of rotation from contact. With shoulder rotation depleted, bringing the bat to contact is left to the smaller muscle groups of the arms – and linear extension of the arms is just not powerful enough to generate good bat speed.

Jack Mankin