Posted by: () on Thu Jan 18 11:52:45 2001

Major Dan,et al-

I have been puzzling about hip action for some time.This is my current hypothetical thinking.The same basic action is generating maximum power for the overhand throw,the windmill throw(fastpitch-arm going same way as in hitting,opposite way from overhand),and hitting.There are differences as well since the arm is going in different directions and the thing being powered is different-long heavy bat versus small round ball.

As for the similarities,in all cases the preferred power generator is "rotational whipping" of the body,a particular kind of coiling and uncoiling often referred to as the "kinetic chain".For simplicity,I think of this as four phases:

1- getting sideways("closed" for overhand,"open"for windmill,stance and inward turn for hitting) and "loading the hips" which consists of tilting the pelvis and bending at the waist so the torso is holding the hip up/cocked.This loading happens with the lifting part of whatever stride there is in hitting.The feel of the proper hip positioning is the same across all these skills and is often best felt in overhand throwing as the front leg comes up to assist crowhopping before the throw.Unloading of the hip needs to be saved for later.

2-COILING/stretching/separating upper and lower half.Torso keeps turning back while lower half begins to "open",however,feet stay in line so this separating is happening by "torquing" of the body as explained well by Mike Epstein.In hitting and windmill,the axis of rotation is staying back/vertical,even though the windmill pitcher may be launching the whole body forward.In overhand,the axis is moving forward/preparing for whipping of the arm/bending forward at the waist,but in all cases,the stretching is assisted by the back leg turn/ankle roll sending a twist upward to the back hip.This ankle roll/back knee turning down/in should be timed to start the back hip turning WHILE THE TORSO IS STILL GOING THE OTHER WAY.

3-UNCOILING-theoretically,the best time to have the torso begin to turn forward by the pull of the lower body is when hip turn is at maximum velocity.This is achieved by "unloading" the hip,which must be kept loaded until this point.This unloading is mostly a result of differential use of trunk muscles and not dependent on front foot plant,for example in the overhand throw it starts as the front leg "turns over"while the front foot is still in the air.Mike Marshall would call this midair move an example of "internal inertial resistance".In this case of pitching the front foot will be pointing to home plate by the time it has planted,indicating that there has been quite a bit of hip rotation.So it is really the front side that leads the uncoiling triggered by the hips unloading.In the case of hitting where you have a big bat to lug around,this unloading is accentuated by foot plant and the use of the front leg/ground connection.The angle of the front foot plant will be less than in pitching,but somewhat variable depending on individual style.In all these activities,the legs tend to work together with one heel coming up and the other going down.

4-WHIPPING-My interpretation of Paul Nyman's observations is that whipping is the major supplier of energy for batspeed.If momentum of a balanced body system is conserved,then if the hips/lower body are slowed/stopped,there will be great acceleration of the turning upper body to keep the product of mass X velocity constant.This requires stopping hip turn and whipping energy up into the torso and requires the front foot to be planted.If the hip is loaded then unloaded then stopped,you get the "up" you would like to see just before/at contact or you get what Shawn calls "leverage".You see the bend come out of the waist and the back arch and the hips go up instead of continuing to turn.The key to seeing this is to watch the back leg.If whipping is done effectively,then ankle roll/knee turn goes up to assist back hip closure while the torso is still opening,then the body turns en block in hitting when the front heel lands,then the hips slow sending the turn up with powerful acceleration of the torso turn associated with equal and opposite reaction going down the back leg which turns behind the front leg.

What we need to teach is effective whipping of the body to get as much power generation as fast as possible,whatever the footwork/"weight shift" required.Jack has made the important discovery of how the transfer mechanics work to get this power to the bat.This requires torque and the circular handpath as opposed to the pure shoulder/arm whipping necessary for pitching/throwing.

Also,Mike Epstein points out how most will lunge without specific lower body instruction so you don't get the vertical axis Jack has found to be so important.