Posted by: Jack Mankin (MrBatspeed@aol.com) on Wed Aug 20 11:00:37 2003

>>> NOTE : The farther away from contact that bat is as the shoulders stop rotating, the weaker the swing.
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I don't quite understand this comment. Could you please clarify. <<<

Hi mb

Professor Robert Adair states in his book “The Physics of Baseball” (and I paraphrase) that it requires about 3 torque horsepower to hit a baseball 400 feet and that the arms can deliver about 1/3 horsepower. Therefore, the vast majority of the energy to generate bat speed comes from the large muscle groups in the legs and torso. Once the body ceases to rotate, only the arms are left to supply energy to the bat and they simply cannot generate great bat speed by themselves.

While doing Swing Review Analysis of player’s swings, I find that some players complete shoulder rotation but the bat is still dragging back near the lag position --30 to 60 degrees of displacement from contact. This is due to poor linkage to body rotation and inefficient application of torque at the handle. Correct linkage and torque provides more efficient transfer of the body’s energy into bat speed and the bat arrives closer to contact as shoulder rotation is depleted.

In a good swing, the rotating shoulders are suppling energy from initiation to contact. Swings that produce home runs in the 400 foot category will always have the bat at (or very near) contact as the shoulders finish rotation.

Jack Mankin