Bio Mechanics

[12 piece bucket]

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.

Like it. Makes sense . . . . Now question for you on the two pics . . . .

A couple of observations on the two pics (drill vs. real) and your comments would be appreciated . . .

1. Shifting focus a bit to the right knee. Note that the spacing between the knees is much better in Hogan's "real" pic. The right leg is MUCH straighter at Start Down than in the "drill" pic. Also there is probably less flexion in the right knee than there was at address at this point. The right side gets "saggy" in the drill . . . would this be due to the COG you described above going parallel to the target line?

2. Is there a "direction" for the left knee in creating the forces you describe above? Should the left knee maintain its flexion AND move toward the target at startdown?

3. At what point in the stroke do the hips lose their flexion in the downswing? Or do should they? See below . ..

THIS


OR THIS?