Posted by: tom.guerry (tom.guerry@kp.org) on Tue Jun 5 14:15:16 2001

Hi All
> > > >
> > > > What is the role of the hips in the baseball/softball swing? Does hip rotation drive shoulder rotation? Or, does the hip serve more as a stable platform for the torso to rotate from?
> > > >
> > > > Hip rotation, or the “popping” of the hips, has long been herald as a key to generating power and bat speed. But if we closely examine the lower-body mechanics being taught by some of today’s most knowledgeable coaches, we find the answer to the above questions in doubt. Just how much does the hip rotation contribute to shoulder rotation?
> > > >
> > > > As an example, let us consider the “Sequential 3 step” approach. --- In “step 1,” the batter assumes his normal launch position. – In “step 2,” the batter ‘squashes the bug,’ fully opening the hips while keeping the shoulders closed. – In “step 3,” the batter rotates the torso and swings.
> > > >
> > > > It is important to note that the author shows a complete pause between each step. This means that after “step 2,” the lower body has assumed the contact position. ---The lead-leg is fully extended, the back-leg forms the “L” position and the hips are stationary and opened, the upper-body is still in the launch position (I think this would qualify for “maximum separation”). --- From this position, would not the hips serve mainly as a stable platform for the shoulders to rotate from? Would not the contraction of the torso muscles rather than the lower-body generate rotation?
> > > >
> > > > But what if the contraction of the torso muscles occurs with less than maximum separation. Say 80% separation of lower to upper body. Then, how much does the hip rotation contribute to shoulder rotation? --- Your thoughts.
> > > >
> > > > I made this post in light of a post by Melvin on Wed Apr 25, 2001 Click Here --- Read it again and see what you think.
> > > >
> > > > Jack Mankin
> > > >
> > >
> > > Jack -
> > > If a hitter opened their hips, then came to a full stop, then rotates the shoulders using only torso muscles, that batter is going through the correct sequence but in a disconnected, extremely inefficient way. This is fine for teaching/demo purposes, but is not a proper swing. I don't know of anyone who really does this when actually hitting.
> > > I consider transfer mechanics the use of the torso to channel the energy of the lower body (legs/hips) into shoulder rotation. Without proper transfer mechanics, the lower body work is lost - slipped transmission is your excellent analogy.
> > > Don't you think that the large powerful muscles (quads, gluts, etc) would do a better job of creating raw energy/power than the torso muscles?
> > > IMO, the torso's main job is to make sure the transmission doesn't slip, not act as the engine.
> > > I'm not sure where you are going with your post. By the way, who is the author you refer to above?
> > >
> >
> > Hi Jack,
> >
> > It's a no win situation, the hips are a very important link. Hip rotation is part hip rotation and part torso explosion (pop). Trying to separate the hips into a single event without total body involvement (musculature, trunk/torso) and without the next link the shoulders (upper torso or shoulder girdle), is very difficult.
> >
> > You do need separation, hips open, top half closed (initiation, keeping the shoulder in there) for maximum use of the trunk/torso. There will not be any 'pop' without torso explosion.
> >
> > If anything the weakest portion of most hitters is how they use the torso. With good rotation, hips, torso there is no 'break, pause' in the action. The shoulders may need to stay closed longer. The hips and torso must rotate without breaking force production or momentum.
> >
> > Your post is a good example of why I don't use the squash the bug analogy.
> >
> > Shawn
> > Jack,you ask does the hips drive shoulder rotation,take the hips out of the equation and see how hard the shoulders and torque hit the ball.Either keep the hips completely closed through follow through or open them up completely with closed shoulders and see what the ball does.

More interesting reading at:

http://setpro.com/NEWWEB/mmax02.htm

This is info more specific for hip turn in pitching,but there are some similarities.In pitching there is linear to rotational conversion and rotation and motion about complex axes and a benefit to pushing the rotating body forward,etc.In both there is momentum transfer through the kinetic chain which is characterized as dynamic-torsion created by twisting and untwisting the body which transfers momentum and static-pulling the torso around adecelerating lower body after the two have begun moving together due to torsion.

The torsion part accomplishes best momentum transfer by making the link to the torso when the hip turn velocity is maximum.Once things move together the muscles can add to torso rotational velocity by pulling.Is this how others interpret this?