Posted by: Jack Mankin (mrbatspeed@aol.com) on Thu May 6 01:48:14 2004

>>> Agreed - torque is constantly applied; 1.) CHP forces bat angular displacement and 2.) The hands are always in a push/pull relationship.

However, as you indicate:

"During pre-launch and initiation, the Top-hand is being pulled back around a slower moving bottom-hand (thus THT). As the bat approaches contact (or from the lag position), the bottom-hand is being pulled back around a slower moving top-hand (thus BHT)."

(A) >Does the relative speed of a hand to a fixed position on earth not indicate, in an absolute sense, which arm is supplying more torque power at each stage of the swing?<

Not really, in a good swing, pressure sensor pads on the bat handle indicate the hands are exerting a fairly even force.

(B) >If legs and hips contribute only to CHP (equal to both hands by definition), and not THT or BHT, can we not infer:<

Shoulder rotation supplies almost all of the power to the to bottom-hand for both THT and BHT. Once the back-elbow lowers to the batter’s side, it also supplies most of the power to the bottom-hand for BHT.

>> 1. When THT is dominant, the muscles of the lead arm (bicep) should be fairly relaxed (and stretched) - since the lead hand is moving slower relative to earth. <<

That would be a true statement during pre-launch torque. But during initiation and THT, the force applied to the knob end of the bat by the bottom-hand (via lead-shoulder rotation) can not be overemphasized. One of the biggest problems I find with most hitters is not making optimum use of the lead-side.

>> 2. When BHT is dominant, the muscles of the lead arm are contracting, causing the lead arm to pull in toward the chest. This results in the lead hand moving faster relative to earth. <<

For most pitches, the lead-arm remains in a fairly fixed position from initiation to contact. The lead-arm contracts very little if any during the swing. It serves mainly as a “tie-rod” to connect lead-shoulder rotation to the bottom-hand. It is the lead-shoulder pulling back toward the catcher (105 degree position) that pulls the bottom-hand back creating the “hook” in the hand-path and BHT. But in order to generate maximum BHT, while the bottom-hand is being pulled back, the top-hand must be equally driven forward by the rotation of the back-shoulder (back-elbow remains in the “L” position). – BHT is the result of equal forces from opposing directions.

Jack Mankin