[bioengine]

Good post . . .Interesting stuff here . . . we are now back on track hopefully from all the COM COAM mess . . . this is the meat of it. . . . This is how people improve not that other crap about whether CF is there or not.

So let's have some further discussion on what you've postedabove. I think this is VERY important stuff.

Really like the part about Hogan's knee action . . . Interesting that what he prescribed doing wasn't what he actually ended up doing.





To your point about Hogan's left knee maintaining its flexion . . . . you can see this very cleary in comparison of the two sequences. Also the left knee maintaining it flexion obviously has implications to the other components. Particularly the slant of the hips, spine, and shoulders . . . as you know the club responds accordingly (altering plane angle, angle of approach & attack etc.) . . . so the pivot has HUGE geometry implications. With regards to when and how certain segments get in line.

So you have mention sheer forces (sp?) force across the ground and vertical . . . Is this the left knee piece you mentioned?

Another question . . . could you expand a bit on the lateral bending of the spine vs. the hips going forward. Would the hips moving forward not also creat tilt in the spine?

The reason I pointed out Hogans Left knee flexion is so you could see he stabilized his lower body.

Ok let me add here so more info to develop a better understanding of lower body mechanics
Center Of Mass is where weight is central.Safely say the belly button.
COP Center Of Pressure is the center pressure between the feet.

Normal forces are the normal force applied perpendicular to ground by golfer through the feet/ground interface.

Shear forces are forces applied to parallel to or along the surface of the ground by golfer through the feet/ground interface.

A golfer starts with a shift of the center of pressure toward the rear foot as the club is "taken away" during the initial portion of the back swing. This shift moves the center of pressure behind the center of mass relative to an axis running along the target line. As the golfer nears the "top" of the back swing and begins transition from back swing rotation into down swing acceleration the center of pressure shifts forward toward the front foot. It is this action creating forward momentum that facilitates the production of shear force at the feet/ground interface. Ground reaction to the shear force created by the feet produces a force couple, which is translated through the legs to the hips segment. The force couple acts on the hips segment to produce torque and rotary acceleration. Once speed is transfered the lower body then stabilizes and the hips decelerate at impact.

The main reason for right lateral bending is so the right arm can react low point in the swing.
You can still move forward and maintain the hips and shoulders to be perpendicular to the spine.
The only time the hips can have an impact on lateral bending is if the left side of your lower body isn't stabilized or anchored.
Although this is a lower body stabilizing issue not spine related.

When hogan does his drill can you notice he lost flexion in his left left leg, his hips are open left and his upper body is square to his hips. Hogan lost his ground forces and lower stability. If hogan did this he may create a superficial hip speed, although he wouldn't have lower body stabilization and hip deceleration. this wouldn't allow hips speed to be transfered to his upper body or Load and fire his muscles.

Again the question remains was Hogan really aware how he created hip rotational speed or the demonstration is how he felt was how he created hip rotational speed. I'm not sure Hogan was aware how important the ground forces he created was the essence to Hogan creating hip rotational speed, lower body stabilizing at impact and hip deceleration, which allowed speed to transfer to his upper body, load and fire his muscles then his upper body would square up to his hips.

What we think or feel we are doing sometimes can be totally opposite to what we are truly doing.