Posted by: Zig Ziegler (zigz@motiondnacorp.com) on Mon Jul 31 07:52:58 2006

Morning Jack,

Thanks for your response. First I think we should get some clarifications. Can you tell me what equipment the company who did your motion studies used. How many sujects did they test? what were they looking for in particular? Everything, bat velocity, ball exit speed, etc.? Just for clarification.

Most of the research I have come across in the last 20 years of working in the field of athletics (as an athlete, coach, and scientist) is that the subject fields are limited and the outcome is clearly predictable.

Our mission is to improve the performance of athletes and reduce their risk of injury. As a result, we are not setting out to prove or disprove one thing other than the body must have the ability to perform the task at hand (which comes from strength, balance, flexibility, coordination, vision, etc. all physical tools.), we are searching for any and all potential issue which impact performance and may result in injury.
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You said "Our motion studies of the swing produced basically the same data on the acceleration and deceleration of the hips, shoulders, limb joints and bat segments that you found. However, we came to different conclusions regarding the deceleration of the different segments."

My question is what conclusion did you come to with regards to those segments? Do they play are role at all at contact? And if your only concern was the bat, how much attention did you or they pay to the other segments? Even in a review of reports from the American Sports Medicine Institute in Alabama, their reports only focus on getting to certain velocites (hip rotational speed, shoulder rotational speed, etc.)
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In my earlier statement to you, I wrote, “Regardless of the speed that is attained with the acceleration principle, the hitter has to be able to control it by effective decelerating the previous body segment.”

You replied:

"You seem to be saying that for the deceleration of a segment to be effective, the batter must be able to time when the muscles driving the segment are relaxed. – We found no evidence that the batter controlled the deceleration of a segment.

My response is this:

With a basic understanding of muscle physiology, it is important to understand the reality that a muscle working to accelerate on body segment (agonist) is being supported by an antagonistic muscle which must help contral the rate of contraction. It is the strength of agonist which slows the hips in rotation.

At the hips for example, during the swing the lead leg would be considered agonistic on the inside and antogonistc on the outside. The internal hip rotators of the lead legare responsible for feeling of rotation at the "hip socket" (this is real in defense of the poster referring to where the rotation occurs). The back leg's agonist assist the lead leg with rotaton of the major body segment which cannot rotate on its own (The Pelvis). Rotation is not a movement of the pelvis. At the same time the back legs antagonists work to decelerate the leg otherwise the agonist would cause uneccessary movement.

In common thinking and without the application of knowledge of how the body works, a casual observer might be able to say "the back leg starts rotation and the lead lead stops it." Or something like that. But that is not the case. Both legs play a role in starting and stopping the rotation of the pelvis foloowed by the upper body, and the rest. Because those segments cannot rotate on their own.

So your statement..." We found no evidence that the batter controlled the deceleration of a segment." Is 1005 flawed. The evidence exist in the mere movement of the human body. So you must not have been looking for it. And that's okay, becasue your philosophy is bat speed. but speed doesn't occur without acceleration and deceleration of multiple body parts.

Even for the shoulders (upper body) to rotate, the pelvis must stabilize. That stabilization comes not just from the back and abs, but from the glutes, hip flexorst, internal leg rotators and external rotators.

Jack you stated.... "We found the deceleration of one segment was induced from the dynamic load demands of accelerating the next segment. I think Tom Querry refers to this as, “Sucking the energy out of the system.” In other words, the rotational momentum of the segment is depleted to accelerate the next. The greater the load demand (greater work being done), the greater the deceleration rate.

My response is that yes Tom is correct. However, the acceleration is affected by the ability of the previous body segemnt to decelerate and transfer the energy. So the conclusion statement takes into consideration the entire process and lumps it all together. But deceleration is not just becasue all of the gas ran out of te tank. Afterall, even a car rolling without any power can be slowed faster if you apply the brakes. That braking would be what you and Tom refer to as "thegreater the deceleration rate."

I'm going to break your next paragraph into multiple parts.

Jack you also said..."I would also comment that data from tests conducted by five different bat companies conclude that the forces applied at the handle to accelerate the bat to contact in not a factor on the ball’s exit speed from the bat/ball collision."

My response is that I highly doubt that the bat companies have an interest in what the rest of the body does. Theyr are usually pretty slow when it comes to embracing anything other how to sell bats. But that's their core business so it should be expected. So as a result, why would they expect the force to play a role. But because of physics and physiology, we know those forces do play a role when that forces is attached to a large object or a smaller object.

If that were not the case, why would we hear announcer say "he muscled that one out for a hit." (and that is true.) many times a batter is just so strong that he gets a hit that would (among weaker or less prepared batters) be a slow dribbler to an infielder instead of dropping for a base hit over the infield.

The ball’s exit speed depends on the bat’s mass and its contact velocity. Therefore, the quality of the batter’s mechanics (or Kinematic Sequence) used to accelerate the bat has no bearing on the ball’s exit speed. It is how much bat velocity attained by contact that counts.
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> I think it’s possible that Adair’s contention that ‘torque (opposing forces applied at the handle) is not a factor in the swing’ may have come from his misreading these bat company reports. -- Note: They did not say that forces applied at the handle were not a factor in acceleration of the bat-head to contact. They said it was not a factor during the bat/ball collision.

To this I issue a challenge. Hold a bat losely in your hands. If you make contact with something, will you hit it harder than if you wer holding on firmly. If barry bonds does not have the strength to hold on to the bat and absorb the contact the n the bat must absorb that contact by it self. If he is used to being able to absorb the contact all the way down to both legs, the ability to absorb and redirect the force of the ball is greater. (yes let's not forget that the ball is supplying force at contact too)

And finally you siad.... One additional note: Zig, there is another factor we should consider in our discussion. -- How much of the deceleration of a segment could be attributed to the contraction of the muscles reaching their limit?

my response is there is more than one muscle at work hear in each segment as I have stated earlier. The limit is accelerated by the strength and flexibility of the opposing muscle. The two must work together.

I am glad to see you are at least exploring more information about the swing. It seems to me you and I might benefit from getting together and writing a book. or release a new set of videos. At least, the invitation is there on my part. I still believe you are closer than anyone else out there, but we must take the principles that it sounds like Tom is trying to get accross and put them together in an easier to understand way. You cannot teach those antagonistice muscles to play a role in the swing, just at pitchers cannot teach the antagonist muscles to play a role in throwing. Decelerators do their job quietly without having to be told what to do or when to do it. its the accelerators that must be trigger by your intent.

Now, I am into my busy week and will respond to posts at my convenience. If I do not respond in a timely fashion, it is not because (as some of your posters would say "I am in hiding or can't find the answer). Its just that i am busy. If you have a pressing question send me an email and we can get together for more discussion and then come up with a way for you to communicate it to your readers.

By the way on Satrday, I sent a response to several questions Tom asked, but I have not yet seen it appear? Was it rejected for some reason. Also, if I have not made something clear to any poster is reading our debate, let me know and I will try to explain it better.

I would love to help out Jack in way I can to improve the sport. Thank you for your ear.

Have a positive day!