Posted by: tom.guerry (tom.guerry@kp.org) on Sat Feb 26 09:40:07 2005

 > So, in an effort to coordinate his movements, so he is using is hips and legs during his swing, I thought he needed to have a point of reference as to when to trigger his hands. Since he does do the knee and hip rotation already, I thought that he could cue the initiation of his hands at the same time as the knee begins it's rotation. If you look at all of the video's on this website (http://www.youthbaseballcoaching.com/swings.html), every one of those guys have their hands starting forward when the back knee begins it's turn. And actually if you look closely at the timing of the hands and back knee throughout the swing, it is almost as if there is a rope tied between them, because their movements seem to be so much in synch.
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> I could be way off base here, but I am trying to give him an easy way to get his swing together.
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 Hi Rob
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> It will be a great benefit to your son that you are studying the swing mechanics of the best hitters. I must point out though that many batters with lower bat speeds rotate their hips while bringing the hands forward. I have received hundreds of videos for swing analysis of hitters who have rotated the hips while extending the hands. The problem is - their bat-head is still lagging 40 to 80 degrees behind where it should be.
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> I impress on these students that they will never become great hitters with mechanics that concentrate on accelerating body rotation and the hands but leave the bat-head dragging. Great hitters generate great bat speed because their mechanics apply forces to the bat that accelerate the bat-head around the entire swing plane. This means that during initiation, the bat-head is first accelerated rearward (toward the catcher) before it arcs around toward the ball. This keeps the acceleration of the bat-head in sync with
shoulder rotation instead lagging farther and farther behind the power curve.
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> Rob, there are some drills I use that help a batter learn to rotate the bat-head in sync with body rotation. However, they do involve terms like CHP (circular hand-path) and torque (applied by both the bottom and top hand – THT & BHT). You indicated a reluctance to use these terms but if you are interested, I can post them.
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> Jack Mankin

Jack,Rob,Shawn et al-

I think Rob's video description is inaccurate, but we can only see what we (want to) see/ video is limited to surface detail and is extremely subjective.
I think Jack's drag description is extremely good and important.

My personal approach to interpreting video includes the importance of the upper limbs and lower limbs working in a synchronized fashion when the body is performing a good rotational swing. I also personally think a key to a good quick swing is optimal last quick bit of coil/stretch ("xfactor stretch"),but not absoulute degree of muscle stretch separation, in fact the less the separation, the quicker the swing IF there is a last quick stretch and reversal of torso muscles/soft tissues to power launch. The second great key to the swing is what Jack describes so well as "transfer mechanics" so things stay in synch
with body rotation so the bathead turns as opposed to dragging the bat longitudinally.

An important way these two things -good stretch and efficient bathead acceleration- are related has to do with the timing/synch of the upper and lower body as Rob has indicated. BUT, I would agree with Jack that if you bring the hands when the back leg turns, this will push the hand and drag the bat. It is also very hard to determine on video when the back leg actually turns. There can be flex of the back leg and some back leg motion when the legs/knees spread and then the back knne can actually turn out some as the hips turn open before the stride foot bears weight and then the back knee turns in and
down to suport ongoing hip turn.

I prefer to think of the lower body/limb action in relation to what the arms/shoulders (scaps) are doing. I think of "coking the hands to load the torso" mainly via the pinching of the back scap toward the spine. Typically, as the back elbow goes up and back, the bat finishes coking as it "centers" toward the pitcher.This is synched with the legs/knees spreading apart (leg aBduction as back arm also aBducts/lifts) and with the weight going forward.

Next there is what jack describes as "pre-launch tht".I find that this is primarily from "external rotation" of the back arm while the back arm remains extended and the back scap continues "loading" (while the back scap cannot continue to pinch,the muscles continue to contract to tighten the entire shoulder link as it prepares to be later driven by the middle up uncoiling of the trunk/torso muscles). Ther cannot be very good "pre-launch tht" if the back arm was not previously "internally rotated" and kept that way.It should have been internally rotated earlier in the swing when the "hips coked" as the stride foot was lifted.

SO, IF the back arm was internally rotated with hip cok and kept that way, and IF the back scap was pinched and the back arm lifted and extended behind the back as the torso loaded, and IF the back scap continued pinching as the legs spread and the weight went forward. THEN the bat would begin to uncok/accelerate back toward the catcher (pre-launch tht) primarily via external rotation of the back arm (this is also how the throwing arm loads in preparation for rapid acceleration primarily by later internal rotation).

So far, then.we have stated how/when the back arm got to be externally rotating. This "pre-launch tht" phase is when the body begins to load by coiling.Prior to this the hips coked, then the handcok/torso load took place, now the body is loading by coiling.(weight is also shifting forward and the center of gravity is lowering as the player "sits".Epstein calls this part of the swing "winding the rubber band".What is required among other things, is that the hips begin to turn open as the hands "stay back". As a necessary part of
the hips turning open, the back leg will start to turn, but only after the hips/thighs have been stretched by the lead leg externally rotating/turning open as the back arm externally rotates/pre-launch THT begins.

I would state the general sequence as back arm and front leg externally rotate
together, although it is probably the case that the arm should wait until just after the front leg begins to turn open before it begins to uncok the bat/begins to externally rotate/ begins "pre-launch tht".

Just after this, the lead arm and back leg will begin to INternally rotate. The back leg will work with the front in supporting the hips in turning open while the lead arm will begin to lift the lead elbow and will begin to assist more in applying torquing force to the bat handle (preparing for transition from "pre-launch tht" to "tht at launch").This results in the bat accelerating its uncoking/turn back toward the catcher as the hips are opening. This in
turn will reactively assist the "hands staying back" which is necessary to "wind the rubber band"/begin a good body coiling sequence.

If as Rob suggests, you bring the hands at this time when the back leg has begun to turn, coiling will be interrupted very early and ther can be no "tht at launch" which is so important.

"THT at launch" is the same phase of the swing that epstein describes as "drop and tilt" and similar to Lau's "pulling the knob of the bat with the hands not the shoulders". This is when the all important "xfactor Stretch"/last bit of stretching of the torso trunk muscles occurs. The hands continue to stay back at this point becasue the lead arm/scap action continues to torque the bat handle, even after the torso has started to turn open because the shoulder link is turning more slowly and in a slightly different plane fron the hips. There can then be a quick reversal (elastic properties of muscles/soft tissues as opposed to slower muscle force production/contraction become primary here) as the handpath is launched by the in sequence middle up uncoiling. AGAIN, not by pushing the handpath outprematurely as jack has noted (hands stay back and bat turns in accelerated fashion-"bat tip blurs"-with last bit of body coil being assisted by this before a quick efficent reversal of coil launches the now tightly connected shoulder/arm/handpath/bat link in its "CHP".

Rob's cue will tend to interrupt coil and drag the bat.