Posted by: Dave P () on Wed Nov 8 17:43:28 2006

> >>> I believe that JJA's position was misrepresented. JJA never stated his position on whether or not F=mVV in calculating what percentage of the swing is accredited to CHP, and what is accredited to torque. What he did question isyour statement that half the batspeed comes from CHP, and the other from torque. I mean no disrespect, but JJA is contending that that half of the batspeed is 50 MPH gained from a CHP, and the other half is 50 MPH gained from torque, the total batspeed should be 100 MPH. These are the calculations that would result if one takes the latter statement literally.
>
> Again, I am not trying to start fights. Rather, I am merely suggested that JJA has been misrepresented here. <<<
>
> Hi BHL
>
> BHL, I stated that about half of a batter’s bat speed is generate from the CHP and half from torque. I know enough about physics to understand that for a batter to generate a 100 mph bat speed, he would need to produce over 70 mph from his CHP alone and over 70 mph from torque alone.
>
> JJA’s position has not been misrepresented. He has stated a number of times that if my test show that I can generate 45 to 50 mph from the CHP alone and 45 to 50 mph from just torque, then I should he able to swing 90 to 100 mph when applying both. That is not supported by f=mvv.
>
> Jack Mankin

Hi Jack

I can not agree with you with the statement that half the speed comes from CHP and half the speed from torque and I will try to explain. To start off I will say that I understand your ideas Jack and I think that you have done alot in the area of study of the swing.

In order to generate an efficient CHP your body must put you in the proper position accomplish this. If your hips, torso and shoulders do not rotate around a stationary axis your hands can not create a CHP. The axis of rotation is slightly leaning back away from the pitcher and because of Newtons third law for every action there is an equal and opposite reaction the back leg must go towards the pitcher while the front shoulder will pull back to the catcher. Any deviation from this will create a flaw in the CHP and will decrease the efficieny of the swing and the speed of the swing. Therefore the bathead speed is effected by the motion of the body not the CHP. The CHP is a result of body mechanics and is a resultant force not a proactive force.

Poor CHP can however decrease the effectivness of proper body mechanics and can effect the speed of the bat and may reduce but not elliminate bathead speed. Linear hand mechanics do not produce bathead speeds of CHP but they still produce bathead speed.

Torque however adds to the total bathead speed and is directly related to the batters ability to combine CHP and torque near the end of the movement just prior to contact with the ball. Torque can be produced indepedently to CHP but is the catalyst that drives the conversion of body energy to maximum bathead speed. Here is an exerpt from a biomechanical online reseach magizine to help explain this.

"Ball Velocity Hinges On Late Wrist Cocking

The relationship between wrist-hinge angle and ball velocity is strongest within the last 40 milliseconds before impact, according to UPMC research, suggesting that even golfers with high ball velocity are typically unable to maintain a cocked wrist position throughout the entire swing.

Assessing the swings of 109 right-handed male golfers, the investigators found that wrist-hinge angle at the top of the swing did not differ significantly between golfers with low, medium, or high ball velocity. At the lead-arm-parallel position, about two-thirds of the way through the downswing in terms of time, the average wrist-hinge angle of the medium- and high-velocity golfers differed significantly from that of the low-velocity golfers, but only the last 40 milliseconds differentiated the two fastest groups from each other.

"Although I'm speaking as a researcher and not as a golf professional, our results suggest that a golf instructor should be encouraging golfers to maintain their wrist-hinge angle as long as possible, provided that doesn't affect the rest of the swing," said James M. Smoliga, DVM, a doctoral student in the NMRL, who presented the findings in June at the annual ACSM meeting."

Though this is golf it is truely the torque aspect of swinging a baseball bat. Highest bathead speed is produced when torque is produced closer to contact.

Hitting is a multidimensional movement that requires more then one formula to determine bathead speed. Every movement prior to contact is governed by biomechanical principals and each movement will affect the movements that are occuring simutaneously and there resultant forces that then affect future movements. Many times when a person focuses on a single event in a multidimensional movement they lose focus on the fact that many parts of the event govern the result and one or two forces do not govern the whole event.

With Reguards

Dave P