Posted by: tom.guerry (tom.guerry@kp.org) on Tue Sep 11 08:06:44 2001

>>> My views on this may be somewhat idiosyncratic, but here goes. Much of this is more in terms of teching "cues" rather than reality.
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> The primary center of "feel"/proprioception/control of the lower body motion is in the hips. Good " balance" and supporting positions of the feet must be learned, but focussing primarily on the feet or legs is like the tail trying to wag the dog and will not result in adequate hip rotation. I like the feel of "striding to balance", then "dropping the front heel" as a "trigger" for a strong "hip turn". I think these cues encourage good separation and powerful hip turn. Pushing from the back cues do not work as well as they often discourage separation of upper and lower half or swaying motion rather than balanced rotation of the body (rotation around a stationary axis as Jack describes it). Sometimes I do add the cue of "driving the back knee forward" as a way of teaching the feel of more powerful hip turn. I also teach windmill fastpitch pitching which has very similar lower body action using the same cues of front foot plant "triggering " hip turn sometimes assisted by "back knee drive" if hip turn is weak. The pitchers do not have the added task of having to react to the pitch by varying front leg action/timing.
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> More theoretically speaking, what I see on video of "optimum" home run swings is usually incredibly fast "hip snap". Look at the recent ESPN clip of the first 60 of Bond's homers to get a feel of how he rotates the body. When this happens in many power hitters(Bonds is an exception because the way he sets up his body's axis of rotation, he usually stays on the back toe)they come up on the back toe, then hip turn decelerates whipping momentum into the torso. The back toe then drags behind the front foot with reactive torque as momentum goes into the torso, then into turning the bat as long as the circular handpath is maintained. This toe drag is quite pronounced in some-Mantle and Aaron, for example. The toe drag stops and the back hip falls back(accentuating the prior "up" thrust of the hips before this)when the hands cast away from the axis of rotation with a second wave of reactive torque going down the back leg and turning the back ankle back. This second kind of reactive torque is the only kind seen in "upper body swings" in those hitters who do not separate the upper and lower half then sequentially transfer momentum from the ground up like the prferred "lower body" hitters do.
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> Back toe drag is usually a sign of good momentum transfer in a "lower body" swing. The absence of toe drag is not necessarily significant. Dragging the toe is not a useful cue in my experience, but can be important in video analysis. <<<
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> Hi Tom
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> I doubt that it is surprising to you that I do not place the importance on hip to shoulder separation that you and Mike do. It is not that I haven't charted the swing of some good hitters with a lot of separation, because I have. But, at the same time, I have charted equally as good hitters with much less separation.
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> I strongly believe that separation is essential in setting up a good launch position. "The inward turn" as coined by Ted Williams, is important in bringing the hands to the proper position and stretching the torso muscles for contraction. But I can find no benefit to separation attained from further opening of the hips during the stride. I am sure you have sound reasons for your position and I am always looking to learn.
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> The answer to a couple of question would help me better understand your position.
> --- Let us assume that two batters have the same rate of angular displacement of the shoulders. If one of the batters attained 20 degrees more separation (hips to shoulders) before shoulder rotation began, why would he generate a more powerful swing?
> --- If two batters kept their lead arm in the same relationship to the rotating body, why would more separation of the hips be required to generate a circular hand-path?
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> I look forward to a good discussion.
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> Jack Mankin
>

Jack-

I think some separation and closing are important to permit both transfer of momentum and rotation around a stationary axis.Turning the body "in one piece" seems to inevitably give a swaying motion rather than ground up rotation/momentum transfer.The amount of separation is probably more dependent on an individuals unique anatomy/physiology.Theoretically,the more separation you create and the faster you "unseparate",the more power you can generate,however,the intricacies of the motor system are much more complex.

I would summarize by saying some separation is necessary,but more is not necessarily better.

Epstein does believe there is some direct benefit to increased/max separation and states heuristically that more than 30 degrees "torque angle" means more than 30 homers.Of course,these are people who are already surviving in the majors,and I doubt he has done the detailed video analysis you have.He also states that slim build players separate more than the "thick" ones.