Posted by: Zig Ziegler (zigz@motiondnacorp.com) on Sun Jul 30 10:40:20 2006

Good Morning Jack,

I can most certainly provide an explanation. Unfortunately we have not compiled the data drawing comparison to ball exit speeds and loss of bat speed. It is possible for us to extract from our data, but I can't dedicate the resources to do it. What I can do is pull a sample of 10 to 20 hitters bat speeds, speed losses, and ball exit speed. We are in our busy season, so it will not be something that comes quickly.

As for the kinematic sequence it is a term that identifies the efficiency of energy transfer related to velocities gained from the ground through end of the bat and transfer into the ball. Every motion has an ideal sequence in which things must occur.

In our report, the kinematic sequence is measured by evaluating the rotational velocites of the pelvis, torso, arms and bat. This is the ideal order at which each of these segments must reach their maximum rotational velocity. In the sequence there is a maximum velocity for each segment achieved with an appropropriate amount of speed gain from one segment to the next.

In the ideal swing of an elite hitter, pelvis reaches a maximum rotational velocity of approximately 575 degrees of rotation per second. Transfers energy to the upper body as up approximately 300 degrees of speed gain takes increase the torso rotational speed to approximately 875 degrees of rotation per second.

At this point if the velocities continue to increase at at least the same rate plus a multiplier of of 1.5x (equalling a speed gain of 450 degrees per second), the energy from the arms should allow the arms to peak at a rotational velocity of over 1325 degrees per second.

Next because the arms and bat have the benefit of uncoiliing or releasing with the help of the rest of the body, the bat could reach a maximum speed of more than twice that of the arms or simply a multiplier of four times the speed gain of the pelvis to upper body. This peaks the bat at a rotational velocity of potentially over 2600 degrees of rotation per second.

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 or balance and power will be lost. As a result, stopping body segments is more important than getting them going as fast as possible.

think of the car going 45 mph on the road. If the drive suddenly applyis the brakes there is an order of energy release for those things that cannot benefit from the braking. the wheels will slow, the the chasis, the the body, the anything inside the car. anything not nailed down will fly forward once the other parts of the car stop. Some things may begin to fly forward before the car reaches a complete stop, but they velocity of those things will not be as great. this is the same as the hitter who leaks open or doesn't stabilize one leg or the other.

A car going 75mph will take longer to release the energy to the rest of the car as the wheels will probably skid on the road the drive may risk losing control of the car. this is the same for a hitter.

I hope the analogy helps explain what I am trying to convey. Bottom line is the technical data is just a means of measurement. The concept is all the same.

Zig Ziegler