Posted by: Jack Mankin (MrBatspeed@aol.com) on Mon Feb 7 17:05:58 2005

>>> The hitting-mechanics forum is closed at present for new postings,but here is an interesting thread.

http://www.hitting-mechanics.org/vbforum/showthread.php?t=618&page=4&pp=10

This was an attempt to disprove torque/tht using computer modelling/simulation.

Even though the thread is titled nail in tht coffin {or something like that as Condi might say),it seems to me that one model actually provides some of the best support for THT.

I believe it was "Ironnyman 2" which shows the effect of back arm action in quickening the swing.This is a passive model,but the effect increased with increased mass of the back arm.

I would conclude from this that force production with the scap/arms/hands could do the same thing as increasing mass in the passive system.

Subsequent to this Nyman went through major gyrations to avoid testing this premise.While he demonstarted a force that could be referred to as torque involving the back hand and arm,he claims this does not count because it is purely reactive.

He goes on to say that active force production is not possible because it would have to happen either by back arm extension or internal rotation which degrades the swing.

I do not find this persuasive.I "believe" in fact that force production is possible and essential to quickening the swing.I would also agree that it doesn'y happen via extension or internal rotation.

Nyman also tries to obscure this action by focussing much more on the power of hook action in subsequent models.

At this point my conclusion would be that he has missed the mark by focussing too much on discrediting you and not enough on what might actually be occurring.

I would be interested whether you think his model supports your THT concept.

Perhaps I am just trying desperately to cling to my own belief system. <<<

Hi Tom

From reading many of your posts, I would say it appears your belief system regarding swing mechanics is basically the same as mine. We just describe it with different terminology. We do seem to have a difference of opinion of what forces are applied to accelerate the bat-head during the “hook” portion of the swing (BHT), but I am sure we can resolve those differences with further discussion.

I did not find the "Ironnyman 2" reference in the thread you referred to, and therefore, can not comment on it. However, in my opinion after reading Paul’s statements, he apparently does not accept the definition of torque, “forces applied from opposing directions that cause an object to rotate about a point.” It appears he feels that all rotation of the bat results from a flailing action (force applied at a single point) supplied by the bottom-hand and any force applied by the top-hand (force applied at a second point) has no effect on accelerating the bat-head.

Tom, you are obviously more familiar with Paul’s theories and if you think I have misrepresented them, please feel free to point them out. – Since Paul apparently thinks the top-hand is used mainly for guiding the bat in the swing plane and plays a passive role in generating bat speed, I find it interesting why he would place such great importance on loading the back-scap. Does not the loading of the scap cause the back-elbow, forearm and top-hand to be pulled rearward? If all bat speed is generated from a flailing action supplied by the bottom-hand, and the top-hand only plays a guiding and passive role, why would a rearward pull (or resistance) of the forearm and top-hand from scap loading be of any importance in generating bat speed – unless, forces from opposing directions (torque) do impact the bat-head’s acceleration.

Jack Mankin