Posted by: Dave (cdpaetkau@telus.net) on Mon May 17 12:53:26 2004

Hi Jack and All

Sorry it took so long to get back to the subject and I hope it does not get lost down at the bottom of the page.

As for your question about 'maximum xfactor stretch' you are correct that the word maximum is too extreme. It should read 'optimal'. Too much stretch will actually slow down the swing as the shoulders would never catch up to the hips to before contact which would mean that the energy trnasfer from the hips to the shoulder rotation would never be optimized.

As you observed the hips must open up before the shoulders so that the elbow can be slotted without constriction from the body. Constriction of the body with elbow slotting creates an 'around the body swing' where the hands are moving farther away from the body and unless corrected can cause casting of the hands or excessive circular handpath. This is seen most often by players who get their back elbow behind the back prior to initiating the forward motion of the hands.

Now back to the question at hand 'heel to the sky'. My observations and research into this subject finds that once the back foot internally rotates the front shoulder must open (biomechancially causes the knee to rotate the hips open and because the wieght is on the back foot causes the front shoulder to rotate open to maintain body balance)which and this causes the hands to have forward momentum too early in the swing. Test this out yourself and you will find if you rotate the back foot internally the only way to keep the hands from moving is to put all your weight on your back foot and your shoulders and hips will rotate at the same time which makes your swing only as fast as the rotation of your hips. The transfer of energy from the hips to the rest of your swing is not possible because of the simutaneous rotation of the two parts. For energy transfer to happen there must be slowing down of that particular motion for the energy to transfer. (Download 3D skillcheck from skilltchnologies website to see illustration of kinematic sequencing)

All these points are very important to explain why the heel to the sky is so important to maximize bathead speed. The ability of the hitter to keep their hands back serves two purposes. One it allows the hitter to create the xfactor stretch and increase bathead speed. Two and maybe the most important it allows the hitter to watch the ball longer and thus giving the brain more information to determine where and when the pitch will arrive in the hitting zone. The more information the brain has about spin, speed and location the greater chance the hitter has in putting the bat in the proper postition to make contact with the ball. If you can gain 10-15 feet of information before committing the hands to the pitch the hitter has a better chance of putting their hands and ultimatly the bat in the proper location to hit the ball square. This all relates to the ability of the hitter to get the back heel off the ground and tranferring weight to the front side.

The one thing I am not sure about is your desciption of the muscles contracting in unison as opposed to sequentially. I think I know what you mean but most students would take this as being a unison rotation of all the body parts which 'feels' like a more powerful swing due to the body rotating together and finishing together which is more of a 'bug squishing' hitting style. For example a 30 mph car speeding up very fast and then slamming on the breaks feels like a fast speed because the stopping and startiing occurring in a shorter time period as opposed to a 60 mph car slowly speeding up and then slowing down gradully. This may not be the greatest example but it does illustrate an illusion of speed that can be created. I feel that a swing where the hips start, then torso, then shoulders and then hands creates a smoother and more powerful swing then if the body rotates all at the same time.

Thanks for your comments and I look forward to some more discussion in this area.

Dave