Posted by: phil (philipland@aol.com) on Sat Jul 30 18:15:36 2005

***I think you're arguing semantics, but I'll respond for the sake of
discussion.*****

> Your quote:
> "In my opinion, the only force that the hands apply directly is a gripping
force."
>
> I disagree with your opinion.
> try a simple experiment:
>
> hold your bat vertically in one hand (either). extend your arm straight
out in front of your face. hold the bat lightly.
> now slowly lower the bat toward the top of your head. do not allow any
movement of wrist joint or elbow joint (freeze them). lower the bat till it
lightly touches (but does not rest) on the top of your head. do you feel the
pressure in the webbed area between your thumb and index finger? do you feel
the pressure on your pinky finger?
> now raise the bat to verticle (again keeping the wrist and arm frozen).
> firing order - pinky, ring, bird, and index.
>
> how about if your fired those fingers at just the right time, in a
baseball swing, that is?
> can't provide any negligible power? how about someone who fly fishes, or
cracks a bullwhip?
>
> I think you should read:
>
>
http://www.personal.psu.edu/users/j/u/jus149/handfinger/handandbrain/handand
brain.htm
>
******Read it. The forces you describe are gripping forces used
sequentially. In your experiment, the bat falls as the grip lessens because of gravity. If you were to start a baseball swing in the same manner, the bat would be pointed to the ground. The fingers would need to exerted their gripping forces not only to bring the bat in plane with the arms, but also to keep the bat from slipping out of the hands, well before contact. Try driving a nail with a hammer using sequential finger firing with your arm and wrist
locked. I don't think it will work. Bull whips and fly rods may use some of the action you describe, but these objects are much lighter, and still most of the action comes from a snapping of the arms and wrist. I don't think you'd be able to snap a bull whip without your arms and wrist being used.*****
>
> Your quote:
> "Forces that effect bat speed (ie hip, torso rotation, unfolding of the
arms, unhinging of the wrists) are applied through the hands, and through
out the swing."
>
> Through out the swing, EXCEPT for the moment of contact?????? How do you
stop the forces applied through the hands PRIOR to contact??????
>
> ****** Again semantics. For an object to move in a circular path, a
constant force must be applied to the object to overcome it's inertia
(tendency to move in the same linear direction). So yes, forces are being applied at contact as well, but they will have no effect on the ball. They will act to continue the follow through and slow the bat down. The point is that the time of contact is so short, that all forces productive to bat speed that effect ball exit speed culminte at contact.******
>
>
> Your quote:
> "Obviously, as the bat speeds up it must be gripped tighter to be held on
to, but the tightening is more reflexive than anything."
>
> Disagree. What about manipulation?
> Please see:
>
>
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Ab
stract&list_uids=15580485
>
>
> In pitching, are the hands only for gripping the ball? And in my simple
experiment above, does it not take force by the hand to lower the bat to
your head, prevent it from hitting your head, and raising it?
>
> ******I don't disagree that manipulation is possible, but in a full swing with a game bat, I don't see how it can be accomplished, or add much benefit. I play alot of golf, and my grip pressure thought is to hold the club lightly. It allows me to free the tension in my arms so that I feel my arms are being whipped through the swing. I can maintain that light grip pressure to the point of release, about the time the wrists begin unhinging and the club's path starts down from its verticle orientation. If I don't hold tight at this point, the club will leave my hands. So I guess what I'm saying is that as I approach contact, my fingers aren't afforded the opportunity to fire sequentially because they're too busy just holding on to the club>******
>
>
> My quote:
> "So, can I conclude that if a bat is permitted to recoil, there will be a
loss of ball exit speed? And what do you suppose would permit a bat to
recoil more from ball impact, a firm or loose grip?
>
> You agree, but say that a FIRM grip would permit the bat to recoil more
from ball impact?????? How do you reason that?

****** My apology. I meant to to say I felt the ball would rebound more from a firm grip. I read ball for bat in your question. But I qualified the answer by saying:

Yes. I would think a firm grip (would allow the ball to rebound farther is what I meant), but in the study of a swinging bat
impacting a ball, there was no difference. I think this was explained by the moment of inertia of the bat. There is also some flex in a bat which may influence recoil in tightly gripped conditions.
In a static situation (as in bunting) firmness of grip may play more of a role than in a bat actually being swung. In the study, their explanation for this (I think) was the bat's moment of inertia.******



So, can I conclude that if a bat is permitted to recoil, there will be a
loss of ball exit speed? And what do you suppose would permit a bat to
recoil more from ball impact, a firm or loose grip?

*****Yes. I would think a firm grip, but in the study of a swinging bat
impacting a ball, there was no difference. I think this was explained by the
moment of inertia of the bat. There is also some flex in a bat which may
influence recoil in tightly gripped conditions.*****