Posted by: Mark H. () on Fri Jan 3 17:13:43 2003

I believe the desired wrist action is different between golf(double pendulum) and hitting(more smooth lessening of angle between lead forearm and bat as swing proceeds).Has anyone measured this?
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> > I did a google search on "double pendulum" and "golf".The assumption is made that double pendulum is desirable for golf and hitting as in this article
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> > http://carini.physics.indiana.edu/E105/swing.html
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> > Any sciencey types out there ?
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> > Does skilltechnologies demo address this ?
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> Sounds like they are talking about flail only at first with torque between the hands only coming into play at the last moment? In any case, I don't see Bonds hitting with his arms at full extension. No doubt you can hit with the double pendulum action and make contact at full extension with great batspeed (assuming you employ torque and flail all the way through), but I don't think it would result in the high BA Bonds showed to go along with his power. This is just after a quick read of the link but it doesn't sound right to me.
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> Mark H.

After looking at the quicktime clip, my reaction is this is what happens if you don't use top hand torque in your swing. You start the swing with a static bat (second part of the double pendulum), and sure, the bat will try to swing back against you at shoulder rotation launch. This is exactly what you don't want. This, if I have him right, results in Nyman's "wasted frames" (correct me if I got that wrong). The bat should be set up to start swinging out immediately (receiving rotational energy)(flail?) by using top hand torque. How much depends on pitch location. More to set up a wider radius for the outside pitch, very very little for the inside pitch (of course if you use Tom's belly up to the plate approach (Bonds) then everything is a middle in pitch?).

I prefer Jack's model of smooth strong acceleration without jerks, snaps etc instead of the double pendulum thing. Now if you are talking about hitting a stationary ball, this might be different. I know beans about golf.

Mark H.