Posted by: tom.guerry (tom.guerry@kp.org) on Thu May 12 12:58:12 2005

Jack this is an extremely interesting and important question in my opinion.

You have stated that when you did your study,you did not recognize any lower body type "absolutes".

I am interested in developing a model that is able to describe some sort of universal sequence/pattern with regard to lower body and weight shift and axis of rotation that may be inferrable from video and useful in teaching.I find input from golf is useful here.Bobby Jones actually figured this part out more than 75 years ago (see-BOBBY JONES ON GOLF) and the same principles apply in hitting.In both hitting and golf you need to avoid what golfers describe as "reverse pivoting" ("bug squishing cue can encourage the "Spin" - if loading/coil is poor,unloading will be weak and compensation will be via a suboptimal axis in support of which the weight shifts back to be carried on the back leg as contact is approached)which gives the body the appearance of "spinning" (hips and shoulders overrotate/hips do not go UP.Bobby Jones noted this was a typial "stage" learners went through.Many things must go right to evolve a golfer to the desired "rotational"/non-spinning pattern including powerful hip turn,well timed weight shift,a firm front side and a "permissive" back arm among others.I think you describe the same suboptimal spin type swing as body turning and bat dragging.Here is the "exponential" thread where you discuss "dynamic load":

http://www.batspeed.com/messageboard/10593.html

Jones findings are extremely similar to yours with the differences I have highlighted between the golf and hitting swing actions,the most difficult to understand being how the baseball swing is quickened/optimized by what you call "THT".

So you should not "spin" in either golf or hitting.In hitting the hips need to open as you "rotate into toe touch" (pre-launch tht happening in many) then acclerate to maximum opening velocity as the hands "stay back" (tht at launch).At this point trunk coil maxes out and reverses and from this point on the front hip shoud be stable and not fall back so momentum is forced up.

In golf when you swing as Jones describes,it creates optimal loading or "xfactor stretch" so that you do NOT spin or fall back on the back foot (reverse pivot) as you uncoil,but remember,uncoiling only happens fairly late about when hands are getting back down to waist high, well into the downswing.