Posted by: () on Thu Feb 3 22:12:11 2005

>>> The front leg acts as the HAND and stops the momentum of the movement forward(now the head stays at center = rotation). Now the energy is then transfered up through the body out to the hands and into the barrel of the bat ( same as cracking the whip ).
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> Hi Swingbuilder
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> I have read similar descriptions of how the body’s linear momentum in transferred into bat speed by the blocking action of the lead-leg. However, this blocking action takes place as the batter is preparing his launch position, before the swing is initiated. This means that the bat is still cocked behind the batters head as the supposed forward momentum is being “transfered up through the body out to the hands and into the barrel of the bat ( same as cracking the whip ).”
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> One of my questions would be, why would the transfer of forward momentum to the bat cause the bat-head to accelerate rearward. With the bat still cocked behind the batter’s head, if momentum was transferred to the bat at this point, it would seem more logical that the bat-head would be accelerate forward toward the pitcher instead rearward.
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> One could claim that momentum is not sequentially transferred all the way up the kinetic chain to the bat. It is only transferred at this point high enough to rotate the hips. This makes more sense, but raises more questions as outlined in my post below from the Archives.
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> Jack Mankin
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> >>> Jack, I would be interested in Bagwell's 1994 stance (.368, 39HR, 400AB, 750SLG). His other years, while good, pale in comparison. <<<
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> Hi Mike
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> I do not recall Bagwell's 1994 stance. I would assume your point is that he had his best year while taking a forward stride instead of his present backward stride. I have no problem with your conclusion. Some hitters may very well perform better with a forward stride.
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> I do have a disagreement with thinking hitters like Bonds use the stride to obtain momentum for the swing. Linear momentum is the product of mass and velocity. Mass with little or no forward movement has little or no momentum to transfer. Hitters like Bonds may pick up the foot and place it five or six inches forward, however, there may be little or no forward movement of the axis (body mass). Therefore, there is little or no linear momentum to be converted into rotational momentum – if that were even possible.
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> Even with hitters like Brett who take long strides with a lot of forward movement, I do not believe the transfer of momentum plays the major role in their hip rotation. The major part of their hip rotation comes from the pelvis being thrusted around by the muscles in the thighs, hips and back – not the transfer of momentum at toe plant.
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> Try it for yourself. Stand up and take a long stride with your hips closed and see how much the hips tend to rotate without using the muscles to thrust the pelvis around.
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> Jack Mankin


> I do have a problem with any whip theory that leads a batter to believe that there is a “crack of the whip” effect that accelerates the bat from shifting weight to a blocked front leg and extending the hands (or knob) in a straight line at the ball. Coaches that bought into that theory keep generations of batters from reaching their potential.
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> Jack Mankin
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Hi Jack

I am not seeing the same sequence as you because when the forward momentum of the hips stop against the front leg the hands are already past the launch position. The point that the forward momentum stops is on heel drop not toe touch. I just watched Bonds, chipper, and Sosa and they were already starting forward arm motion before heel touch and they were all about at the back shoulder.

Jack when there is transfer of energy you must have a mass slow down in order for transfer to be completed and therfor on a kinetic sequence all the parts from the hips to the shoulders must excellerate to maximum velocity and then start to slow down in order for the transfer to be effective. Of course there would be no instant transfer from the hips to the hands because there are parts between the hips and the hands (unless you squish the bug which causes early rotation of the hands to the hitting zone). Terminology of crack the whip maybe not an exact analogy but 95% of analogies are not EXACTLY what happens in the compared motion.

DAve

Dave
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