Posted by: Jack Mankin (MrBatspeed@aol.com) on Sun Jun 26 11:52:04 2005

Hi Tom

My determination that the hips, torso and shoulders rotate fairly evenly around the spine (center of mass) is not based on video clips alone. The most compelling documentation came from my studies with a motion studies computer described in a post from the Archives below. The computer allowed us to study the batter’s mechanics from any point of view. When viewed directly down the axis of rotation, it confirms what I previously described.

You stated earlier that “the desired rotation as more around the front hip.” – If that were true, it would mean the spine would also be rotating forward around the front hip. However, the head (at the top of the spine) remains almost motionless. For the head to remain still means the shoulders must be rotating around the spine – not the front hip.

Jack Mankin
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Re: Re: Re: Re: Closed batting stance

Posted by: Jack Mankin (MrBatspeed@aol.com) on Thu Mar 6 00:43:59 2003

Hi Zig

I am aware of the hard work and dedication you put into your project and you are to be commended for it. During 1996-7, we ran a similar study at the U of CA (San Bernardino) using their newly acquired Motion Study computer with 4 position motion detectors, pressure sensors and high-speed cameras. Sensor points (looked like miniature Ping-Pong balls) were placed at each joint of the batter's body and the linear velocity and angular displacement rate for any limb (or joint) at any point of the swing could be analyzed.


Zig, I am sure the data from our study would confirm the findings you just presented. After analyzing your data, does a batting principle emerge that has not been published or discussed on this and other sites? With the pool of batters we had to work with, I could not find predictable correlation’s between the angular rate of the various sensor points and bat speed development.

Jack Mankin