Posted by: tom.guerry (tom.guerry@kp.org) on Mon Nov 15 10:07:29 2004

Please excuse any blank replies,I have almost figured out what key I am hitting wrong that posts prematurely,but I haven't quite got it nailed down.

I do think it's important to define what is meant by "swing begins" or when this supposed thing happens.Toe touch/heel drop are nice lnadmarks becasue they are fairly easy to agree on,however,they can be somewhat variable in their relation to the ongoing "load/unload cycle" (Nyman description of swing) of the body.

I find another useful set of landmarks for the rotational swing (not so much for nonrotational) is the back foot action.I would say for analytical purposes,especially for computer supported video analysis,you might consider the following context/definitions/landmarks:

Swing phases:

1- hip cock-begin loading of lower spine/hips

2- hand cock- load torso and turn body inward some

3-rotate into foot plant- load body by creating twist/torsion

4-drop and tilt- hip turn accelerates to max to max out trunk torison/create max separation/"front side stretch"

5-bathead fires out with short quick acceleration to max velocity/"escape velocity" at contact (no deceleration/reacceleration,no disconnection/interruption before contact.

One proposed definition of beginning of swing is when the middle out tturning open of the hips begins.

This occurs after "hip cock" and after "hand cock" (back scap pinching and weight/center of gravity strated down and forward) as you begin "rotation into foot plant/as you begin "winding the rubber band" which happens as the "hands stay back" and the hips begin the middle-out turning open.

In video,the back foot will be seen to reactively turn back as the hips start this "unloading",usually (for a strider) when the lead foot is still in the air.

In Epstein parlance,this would be when "counter-rotation" starts "winding the rubber band" as you stride to toe touch/on the way to the "#1 position".

In Jack's model,this is when there is "pre-launch THT"-bat turning back toward catcher/uncocking before shoulder turn starts,while the hands are still "staying back".

The desired back foot action is very different from the "bug squish" action and is often a sign a good rotational mechanics (very hard to make back foot start pivoting this way while front foot is still in air unles you have loaded well up to this point with properly synchronized weight shift).

The "feel" is the feel of starting to wind the rubber band.

There are also many other candidates for when the swing starts.