Posted by: Rob () on Wed Feb 1 19:54:17 2006

> Hi All
>
> I decided to start this month’s discussion with my take on hip rotation. We all agree that rotating the hips is an important factor in the swing. In fact, many seem to believe that if they can get the batter to attain good hip rotation, the rest of the swing will just naturally fall in line. I have always maintained that since the arms/wrists/hands/bat is linked at the shoulders rather than at the hips, the importance of hip rotation is its contribution to shoulder rotation.
>
> I also agree that most of the energy that powers a great hitters swing comes from the rotation of his/her body with much less coming from the contribution of the arms. However, even if the batter prefects his lower-body mechanics to generate great rotational energy, the amount of angular velocity his bat achieves from that rotation is governed by the efficiency of his upper-body transfer mechanics. – “Of what use is a 1000 hp engine … if the transmission slips?
>
> I have found that if a student has the correct mental image of how to correctly initiate the acceleration of the bat head, the mind will develop a sound lower-body program to accomplish it.
>
> Note: As I stated earlier, hip rotation is an important factor in the swing. What forces are acting on the hips to induce rotation is where you find most of the controversy. I will cover that next.
>
> Jack Mankin

I appreciate your insight to the mechanics of swinging a bat. I agree with your analysis of the hips and shoulders creating rotation. However I wanted to point out that connecting the upper half and lower half is the spinal column. Rotation about the spine is extremely important in any sport involving rotation. In fact the hips are part of the pelvic girdle that includes the lumbar spine, the sacroiliac joints and the hips as well. Not only are the muscles of the hips important in generating this motion but muscles including the "core" (pelvic girdle) and the long multisegmental muscles that eventually cross the lower lumbar spine to attach to the opposite hip muscles also need mention. The area between the lower thorasic spine and the upper lumbar spine is an important torque converter that allows this motion to be performed effectively and efficeintly. To me, this is the area missing in the discussion between the hips and shoulders. Thanks for all your work.