Posted by: Major Dan (markj89@charter.net) on Mon Jan 20 13:32:01 2003

Jack-
> IMO the point of the 'sit' or weight shift from back to center is to use and amplify the plyometric response - when a muscle is first stretched, then contracted it contracts more forcefully. Additionally extra energy is stored in the elastic tissue (ligaments and tendons) when it stretches, and that is released in the second half of the movement - the body's rubber bands so to speak.
> Doing the same movement statically bypasses this physiological advantage.
> The difference in the swing is one of explosiveness. Since the hitter must wait as long as possible to read a pitch, then generate a high velocity batspeed in 4/30th-6/30th of a second, the large muscles that initiate and power the swing must contract explosively (speed-strength). The Plyometric response is the best way for the body to generate maximum strength in the minimum of time.
> Your suggested alternative ["Suppose the batter loads by having the proper weight on the front toe in his stance as he prepares the launch position. Suppose his trigger is a little knee cock during the inward-turn instead of a linear stride"] does not offer such a dynamic loading process as far as I can see.
>
> Hi Major Dan
>
> I agree that dynamic loading or plyometric response (as opposed to a static load) is necessary, but I have found that lowering the body can accomplish this just a well as a forward (linear) movement. In either case, linear momentum is not being converted into rotational energy (other that the loading process).
>
> Jack Mankin
>
A 'plyometric' sit can load just as forward movement can load.
(1)Sosa has a pronounced 'down' to his stride - it is as much down as forward. This is a movement similar to a vertical leap. It is more down and up than forward and turn. Is this John C's 'magic moment'?
Bagwell is another down and up guy with the variation of starting down and doing that odd backward stride to load the legs.
(2)Sheffield seems to leap forward and turn against his front leg. Aaron was similar. They both have/had their back foot off the ground during rotation.
IMO these are two different ways to use the body to load. The unloading however is pretty similar - rotation around the spine.
I've seen two other ways to accomplish this.
(3)Nomar is more of a stand and turn guy. He mostly just rotates using his legs to stand and spin. Paul Molitor was also like this. I think this is Teacherman's 'bellybutton' swing.
(4)Mo Vaughn and some other thicker body types fold at the middle - front shoulder toward front knee, then drive the hips forward through that hip/shoulder line with emphasis on the back hip. It is a combo hip thrust and twist. This is a very powerful and quick movement. Bonds does a more elegant version of this.
If you watch, you'll see most hitters bend from the waist as the load the legs. They put their chest over the plate to some extent.
This is the same movement a jumper uses to load before a vertical leap. The jump includes the upper body being thrown 'back' toward vertical as the hips come through coordinated with the legs thrusting upward. The upper body pulls up while the lower body pushes off.
Hitting adds a 1/4 turn to this.

Anyway, I think there is more than one way to load and have mentioned four. They each have elements of sit, stand and turn, load and unload. Different body types, different emphases.