Posted by: tom.guerry (tom.guerry@kp.org) on Thu Nov 28 09:45:31 2002

>>> After reading over your material it appears you
> advocate the upper body and lower going as one piece, as a result,
There would be no separation
> bettween Hips and upper body with hips leading the rotation. Could
you comment regarding why this would be better.
>
> also can this approach apply to throwing, (block rotation.) <<<
>
> Hi Cole
>
> Welcome to the site. --- I think when I stated the hips and
shoulders rotate in “unison”, it sounds as if I feel there should be
no separation between them. Hopefully, a couple of post I made earlier
on this topic may help clarify my position.
>
> ###
>
> Hi Tom & Major Dan
>
> The points made in both of your post are valid and well taken. I
think that either "separation" or "unison" hip to shoulder relation
taken to the extreme is less productive. --- If we mean by "unison"
that the hips and shoulders stay in alignment during rotation, I can
think of no one who would advocate it. For the hips and shoulders to
remain aligned, would mean that the torque supplied by the legs alone
would drive rotation. The powerful muscles the torso would be limited
to just keeping the shoulders in line with the rotating hips.
>
> Taking "separation" too far also has limiting consequences. Allowing
the hips to open while keeping the shoulders closed means the batter
is giving up valuable leg torque angle on a low load movement. Or in
other words, the batter gives up valuable leg torque movement on a
freewheeling hip motion. Having the hips open (maximum separation)
while the shoulders remain closed means the legs will figure less in
the equation. They will have expended most of their torque angle and
shoulder rotation will rely mainly on contraction of the torso muscles
alone. --- This may be sufficient for a lower load shoulder rotation
as used in pitching a baseball or swinging a golf club where velocity
is more important than power. But swinging a 35 oz wooden bat requires
more use of both the legs and the torso (in unison- if you will).
>
> We would all agree that a 20+ degree separation does occur during
the inward turn to the launch position. But in my opinion, any further
freewheeling of the hips during the stride is not productive. At
initiation, both the legs and torso muscles are contracting in
"unison" to drive rotation. At the start of the swing there will be
another 10+ degrees separation. But that separation is due to
overcoming the added inertia of the upper body and accelerating the
bat-head - not freewheeling. From that point on, the hips and
shoulders rotate simultaneously (in "unison" - may not be the best
term).
>
> You may wish to bring up the "rubber band effect" or momentum, I
would be happy to discuss them with you.
>
> Jack Mankin
>
> ###
>
> It is quite obvious to anyone who has studied the baseball/softball
swing that the hips are ahead of the shoulders or hands at the start
of the swing. The hips leading the shoulders start well before the
swing is initiated. In the Frame-by-Frame section of the site (Swing
Mechanics) I wrote, “The batter has rotated (inward turn) his lead
shoulders away from the pitcher.” So the hips already lead the
shoulders by 20+ degrees as the batter prepares his launch position
(look at Frame #B).
>
> Frame #C shows that some (not all) batters develop even more
separation during their stride. I stated, “The lead knee has started
rotating around toward the pitcher;” (not all - after Barry Bonds'
stride his lead knee still points more toward the plate than the
pitcher). This means the hips now lead the shoulders by approximately
30 degrees. All of this occurred before the swing was fully initiated.
From viewing the “Frame-by-Frame” section, everyone should see and
understand that the hips lead the shoulders at the “start” of the
swing. ---But we must also remember that at the “finish” of the swing,
the shoulders will have rotated past (and now lead) the hips. And
after full initiation, the hips and shoulders do rotate at the same
time. When studying the swing in frame-by-frame motion, you can really
see this happening.
>
> I used the term “unison” to denote mechanics, where at initiation,
all the muscles in the legs and torso are contracting in unison to
drive shoulder rotation. This is to distinguish it from “sequential”
mechanics where the batter first contracts the leg muscles to rotate
the hip (while holding the shoulders back) and then later fire the
torso muscles.
>
> Note: There is a 3-stage type of mechanics being taught where the
batter is taught to (1) stride, (2) use the leg muscles to fully
rotate the hips while keeping the shoulders closed (3) fire the arm
and torso muscles to bring the hands and rotate the shoulders. --- I
refer to the hips rotating while keeping the shoulders closed (no load
rotation) as “freewheeling.” For there to be a “kinetic chain” (or
rubber-band effect) that continuously supplies energy from the ground
upward to rotate the shoulders, all muscles in the legs and torso must
be contracting in “unison,” not “sequentially.”
> --- Although all the muscles are contracting in unison, the hips
will still open ahead of the shoulders due to the increased load of
accelerating the upper-body mass and overcoming the inertia offered by
the bat – not sequential timing.
>
> Jack Mankin
>
>

Happy Thanksgiving and Thanks to Jack for the service he provides.The
moderated forum is working well.I would recommend perhaps a published
scheduling of when updates/posts are added to reduce the
redunduncy/"crossing in the mail" of replies.Hope to see the new video
soon.

MY question is when is there maximum separation for a given hitter ?

This is a separate issue from how much separation is good and whether
or not degree of separation can/should be increased,and if so whther
it should be done early as opposed to later in life,etc.

My interpretation of Epstein is that the maximum separation is at heel
drop.There is some separation before this(I prefer to think of this
separation as "coiling" since "counter-rotation" sounds either like
the whole body turning back together or like the upper body is taking
too much of a "backswing") which maximizes as the top of the torso
starts rotating slightly(few milliseconds?) after front heel drop.In
finer detail,perhaps there is more separation for outside pitch and
less for inside,or perhaps the uncoiling could even start slightly