Posted by: Jack Mankin (MrBatspeed@aol.com) on Thu Oct 30 12:06:47 2003

>>> If my thinking is to let everything go in unison, then I try to activate the shoulders, and it is my belief that you should never try to activate the shoulders in the swing, and that is why I consider that "go in unison" to be a dangerous statement. If everything is done from the knee/hips on up, then your shoulders will come naturally and those beautiful hands will soon follow too - very quickly I might add. <<<

Hi Andy

I have often pointed out that energy generated from the legs and hip rotation can not effect bat-head acceleration unless it results in shoulder rotation. For energy from the hips to be transferred upward, the muscles in the torso must also be contacting (in unison). If the torso muscles that contribute to shoulder rotation remain relaxed the hips will simply “free-wheel” and contribute little to generating bat speed.

I would like your opinion on a post from the archives that I wrote on this topic.

Jack Mankin

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Re: Re: Re: kinetic chain
Posted by: Jack Mankin (MrBatspeed@aol.com on Tue Sep 25 22:43:25 2001

>>> [quote] --- Although all the muscles are contracting in unison, the hips will still open ahead of the shoulders due to the increased load of accelerating the upper-body mass and overcoming the inertia offered by the bat – not sequential timing.
[/quote]
We've discussed this before. THis last paragraph of yours clarifies for me how you think about this issue.
I don't really have an opinion on whether the torso muscles are fired consciously either sequentially or in unison. I think we both agree on what the finished product should look like.
My only question is if you have actually had the muscles monitored to see if they are used sequentially or in unison, or if this is just your opinion of what is happening.
As I said, I have no idea myself. >>>

Hi Major Dan

I have found that we seldom disagree on any of the major batting principles. Our discussions have primarily centered on finding clarity rather than actual disagreements.

My statement regarding “sequentially or in unison” is based on deductions made from observations and applying scientific principles – not test data.

I observed that the momentum of my hips was not transferred upward without contracting my torso muscles. For example, two bowling balls are placed one on top of the other. The bottom ball is spun. If we stop the bottom ball – is any momentum, other than that caused by friction, transferred upward to the top ball? --- I found that if I left my midsection relaxed, my legs could open my hips approximately 70+ degrees with very little tendency for the shoulders to rotate. You could hold the shoulders back with one finger.

I concluded: (1) If the legs drive hip rotation while leaving the shoulders closed, only torso contraction will be left to drive shoulder rotation. (2) For the legs and hips to contribute to shoulder to rotation, the torso muscles must also contract in-unison.

Jack Mankin