Posted by: Jack Mankin (MrBatspeed@aol.com) on Thu Nov 28 08:57:24 2002

>>> After reading over your material it appears you
advocate the upper body and lower going as one piece, as a result, There would be no separation
bettween Hips and upper body with hips leading the rotation. Could you comment regarding why this would be better.

also can this approach apply to throwing, (block rotation.) <<<

Hi Cole

Welcome to the site. --- I think when I stated the hips and shoulders rotate in “unison”, it sounds as if I feel there should be no separation between them. Hopefully, a couple of post I made earlier on this topic may help clarify my position.

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Hi Tom & Major Dan

The points made in both of your post are valid and well taken. I think that either "separation" or "unison" hip to shoulder relation taken to the extreme is less productive. --- If we mean by "unison" that the hips and shoulders stay in alignment during rotation, I can think of no one who would advocate it. For the hips and shoulders to remain aligned, would mean that the torque supplied by the legs alone would drive rotation. The powerful muscles the torso would be limited to just keeping the shoulders in line with the rotating hips.

Taking "separation" too far also has limiting consequences. Allowing the hips to open while keeping the shoulders closed means the batter is giving up valuable leg torque angle on a low load movement. Or in other words, the batter gives up valuable leg torque movement on a freewheeling hip motion. Having the hips open (maximum separation) while the shoulders remain closed means the legs will figure less in the equation. They will have expended most of their torque angle and shoulder rotation will rely mainly on contraction of the torso muscles alone. --- This may be sufficient for a lower load shoulder rotation as used in pitching a baseball or swinging a golf club where velocity is more important than power. But swinging a 35 oz wooden bat requires more use of both the legs and the torso (in unison- if you will).

We would all agree that a 20+ degree separation does occur during the inward turn to the launch position. But in my opinion, any further freewheeling of the hips during the stride is not productive. At initiation, both the legs and torso muscles are contracting in "unison" to drive rotation. At the start of the swing there will be another 10+ degrees separation. But that separation is due to overcoming the added inertia of the upper body and accelerating the bat-head - not freewheeling. From that point on, the hips and shoulders rotate simultaneously (in "unison" - may not be the best term).

You may wish to bring up the "rubber band effect" or momentum, I would be happy to discuss them with you.

Jack Mankin

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It is quite obvious to anyone who has studied the baseball/softball swing that the hips are ahead of the shoulders or hands at the start of the swing. The hips leading the shoulders start well before the swing is initiated. In the Frame-by-Frame section of the site (Swing Mechanics) I wrote, “The batter has rotated (inward turn) his lead shoulders away from the pitcher.” So the hips already lead the shoulders by 20+ degrees as the batter prepares his launch position (look at Frame #B).

Frame #C shows that some (not all) batters develop even more separation during their stride. I stated, “The lead knee has started rotating around toward the pitcher;” (not all - after Barry Bonds' stride his lead knee still points more toward the plate than the pitcher). This means the hips now lead the shoulders by approximately 30 degrees. All of this occurred before the swing was fully initiated. From viewing the “Frame-by-Frame” section, everyone should see and understand that the hips lead the shoulders at the “start” of the swing. ---But we must also remember that at the “finish” of the swing, the shoulders will have rotated past (and now lead) the hips. And after full initiation, the hips and shoulders do rotate at the same time. When studying the swing in frame-by-frame motion, you can really see this happening.

I used the term “unison” to denote mechanics, where at initiation, all the muscles in the legs and torso are contracting in unison to drive shoulder rotation. This is to distinguish it from “sequential” mechanics where the batter first contracts the leg muscles to rotate the hip (while holding the shoulders back) and then later fire the torso muscles.

Note: There is a 3-stage type of mechanics being taught where the batter is taught to (1) stride, (2) use the leg muscles to fully rotate the hips while keeping the shoulders closed (3) fire the arm and torso muscles to bring the hands and rotate the shoulders. --- I refer to the hips rotating while keeping the shoulders closed (no load rotation) as “freewheeling.” For there to be a “kinetic chain” (or rubber-band effect) that continuously supplies energy from the ground upward to rotate the shoulders, all muscles in the legs and torso must be contracting in “unison,” not “sequentially.”
--- Although all the muscles are contracting in unison, the hips will still open ahead of the shoulders due to the increased load of accelerating the upper-body mass and overcoming the inertia offered by the bat – not sequential timing.

Jack Mankin