Re: Re: Re: Re: Momentum and hip rotation.
Posted by: THG (
) on Tue Oct 2 16:25:15 2007
> >>> Jack. With regard to the linear contibution I would use Babe Ruth as a prime example of why their is or at least can be a linear contribution.
> The leg load of the inward turn is using the long stride of Babe Ruth induces more of an elastic pull on the body which when unloaded appears to contribute more energy to the swing. As the stride is finished, the energy of the CHPextends through the front leg as Ruth comes around to contact. The energy produced is so great as to cause Ruth to end in a cork screw position.
> I do understand that the corkscrew motion takes place after contact. But I believe the resulting follow through is set in motion because of the energy Ruth generates which was initiated by his downward hitch, inward knee turn and long stride which is a version of the archers pulling the bow.
> I would agree with you that stride length has to do with timing. But the greater the batspeed the more a Sosa or Bonds can use a longer stride, hitch, or other pre launch movements. And I think that we are fooling ourselves if we think hitters that lack the same batspeed and or swing quickness/ability can use those same preset principles and be as effective. <<<
> Hi THG
> After reading your post, I think we are on the same page regarding how the conservation of linear motion can aid in generating hip and shoulder rotation. If I read it correctly, you are contending that the body’s momentum obtained during the stride is conserved in the loading of the lead-leg to do work.
> I think this explanation has merit. Your description for conserving linear momentum is similar to another resent post on this topic. That post used the analogy of a pole-vaulter’s linear momentum flexing the pole. The un-flexing of the pole aided in the height of the vault. In a similar way, the loading of the lead-leg from momentum developed during the stride promotes a stronger extension of the lead-leg that drives the lead-hip rearward and therefore a more powerful hip rotation.
> These are very different concepts from those promoted by Lau and Yeager for how linear momentum induces hip rotation. They basically contend that as the lead-leg blocks forward body movement, the conservation of momentum causes the back-hip to rotate about the blocked lead-hip – like a gate swinging on a hinge. Soon, I will post a clip that illustrates why this theory is not consistent with the laws of physics.
> Jack Mankin
Jack. I agree with your interpretation and would add that the stride extension creates a greater pull (somewhat similar to the torque that is put on the wrists through THT and BHT.) The additional pull stretches the body to create the potential of more energy transferred around the front leg during the CHP.
I also believe that a somewhat similar energy movement can be created if their is a dramatic inward turn/knee and or shoulder/core turn around toward the catcher as in the case of a Jim Edmonds and Ted Williams on occasion.
With regard to Lau, part of the problem with some of his students is that in many instances the CHP appeared to get cut off at the point of contact (or where the bat should meet the ball). And because the hitter has to almost lunge into the plate, the timing has to be perfect. But if the timing is not, his technique results in a very awkward looking helicopter swing that was seen in Rich Gedman.
George Brett talent and intensity mentioned by Lau allowed him to maximize Lau's principles. But it is likely Brett would have hit eventually under any technique because of his mental toughness. The difference in the Lau extension of stride and Ruth's extension is Ruth's movement is more of a lunge in which the entire body is moved forward like Sosa rather than a controlled quiet movement as in Brett.
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