Posted by: daw (daw@bellevue-law.com) on Tue Dec 11 08:58:32 2007

> >>> Is Dr Yeager a proponent of rotational or linear? After watching his DVD seems like his is a hybrid swing. Load linear but swing rotational. Would watching his DVD confuse someone who is trying to develop a rotational swing? <<<
>
> Hi Kupuna
>
> Some time ago Dr. Yeager posted his thoughts on this board and I have read a few of his posts on other boards as well. However, I have not reviewed Dr. Yeager’s DVD nor have I had a chance to read his latest writings on batting principle. Below is a January 2005 post I wrote regarding my thoughts on his theories at that time.
>
> <a href="http://www.batspeed.com/messageboard/19509.html">DR. Yeager’s Whip Theory</a –
>
>
> Jack Mankin


The energy generated by a whip is a "wave" created when the whip is "snapped". The wave then traverses the length of the whip, until exiting at the end with a mini-sonic boom. The "movement" of the whip is the displacement of its non-rigid surface by the wave itself, as the wave travels down its length. (do you ever create waves by playing with those pens with tiny chains on them at the bank teller's station?) With rare exceptions (earthquakes and other overpowering forces of nature), waves don't travel through rigid surfaces and when they do, the rigid surface is likely to shatter.

The "whip" model of hitting suggests a "wave" of energy from the shoulders, through the arms and into the bat. Such a wave, if enough force could be generated to create it, would do nothing to bring the bat head around a circular path into the ball, and would likely shatter the bones in the arms and/or the bat.

Here's a link to one of many available discussions of wave energy, this one specifically dealing with whips.

http://math.arizona.edu/~goriely/Papers/2003-PhysD(whip-waves).pdf