Jim McLean's 6 degree-of-freedom 3D report and other pevis/hips commentary

[lia41985]

At some point, you have to say why it (the word) matters in a golf lesson. That's what I am asking...

I asked this:

Does the pelvis experience negative acceleration, acceleration, or deceleration?

Oh, ok.

Like Negative Alpha down by the ball....

Yup...you are correct Lia. It matters a lot!

I guess...?

 

[Brian Manzella]

You get it, right?

Like negative alpha.....

 

[lia41985]

Negative acceleration then, sir?

 

[Brian Manzella]

Negative acceleration then, sir?

There are plenty of definitions of it out there....which one are you working with?

 

[lia41985]

The non-obfuscated type.

Negative acceleration of the pelvis, then?

 

[Brian Manzella]

Here is my (current working) definition examples....comments welcome. The object is to get the whole forum on the same page with words....

Deceleration - Braking to slow down something that was accelerating.

Negative Acceleration - Accelerating in the opposite (or just different) direction, resulting in "deceleration."

 

[lia41985]

So the pelvis undergoes which, Brian?

 

[Brian Manzella]

Lia...you comfortable with the definitions?

 

[lia41985]

I'm comfortable with you using your own words with your own definitions to form your own sentence, yes, sir. Please, if you could...

 

[Brian Manzella]

Are YOU comfortable with the idea that Negative Acceleration results in Deceleration?

 

[lia41985]

Are YOU comfortable with the idea that Negative Acceleration results in Deceleration?

So that's what you're saying?

No.

That's too imprecise.

 

[natep]

omg

Do you think these two terms have different meanings in this instance?

If so, I think you should explain.

 

[lia41985]

omg

Do you think these two terms have different meanings in this instance?

If so, I think you should explain.

Yes, I and this guy do

Yup...you are correct Lia. It matters a lot!

 

[Brian Manzella]

Here is how it goes...

If you are looking at the hands in the swing, in a reference frame common to 3D and the golf swing or even from a simple 2D view, it is seemingly apparent that the hands slow down pre-impact. Most folks would be quite comfortable with the idea of calling that deceleration.

But, using my definitions above (that I didn't pull out of the air), does the golfer SLOW THEM DOWN? Or, does the golfer ACCELERATE them in the OPPOSITE DIRECTION?

In my opinion, and as claimed as far back as in Search for the Perfect Swing (published in 1969), they are in actuality, going (accelerating) backward.

That's what I teach and preach.

So, using today's forum lexicon additions, I call it Negative Acceleration. In this particular case, Negative Alpha!

You picking up what I'm putting down?

 

[lia41985]

Ya changed yer tune.

That's allowed.

Learn, sir.

So did you write it down, Brian?

Write this down:

It's not the intention to decelerate the prior segment.

It's the intention to accelerate the heck out of the next segment.

 

[Brian Manzella]

Well, Lia, we have been calling the through the ball NEGATIVE ALPHA TORQUE for quite a while, and we articulated it as mentioned above for a long time now, including my talks around the country this year at major seminars.

So, only the words are somewhat new, but thanks for forcing them to the forefront.


Now, I've said a lot, and I intend to answer you question about the pelvis, but what is YOUR answer, sir ?

 

[lia41985]

Is that right?

There have always been folks who thought that there was no way the hips should be moving slower at impact rotationally, then they were pre-impact.

We have been saying for years now that: "You can not make a high level powerful swing—tour caliber or not, long drive champion or not—without pelvis deceleration."
I have been personally teaching folks in the TrackMan era by "giving them the business" — my right hand under their right tush and somewhat on the side of their right leg, my left on their left ribcage, thrusting their pelvis forward and upward with my right hand, while my left hand rotates the ribcage while it assists the tilts of the pelvis and the torso.

I am very confident, and have been for quite some time, that we are the correct side of this debate.

But, one of my undeniable truths of the golf teaching biz is any swing that works on one golfer really well, will work on multiple golfers if taught to them the same way. If that weren't true, there would be a method teacher in the world who could afford to eat at Taco Bell.

And if the method is the thought of a free spin of the hips through impact (which never actually happens, see above), it is usually accompanied with a strong left hand grip, more or less requiring the golfer to be so open pelvis-wise at impact, that the hips simply can't do what they are trying to do.

Emphasis added by me.


Now you're relating negative alpha with pelvis acceleration. Before we used alpha, beta, and gamma to talk about "on the club" torques, usually with the forces being related back primarily to the hands, arms, and shoulders. Now you're talking about how negative acceleration of the pelvis plays into negative alpha force being put onto the club. Nice. Giving the business, certainly

 

[Brian Manzella]

What's your answer Lia?

 

[Kevin Shields]

Ya changed yer tune.

That's allowed.

Learn, sir.

So did you write it down, Brian?

This arrogance is absolutely nauseating.

 

[natep]

Lia, you have issues with the rotational velocity of the pelvis slowing down, but you're on board with actually trying to reverse direction of the pelvis turn through the ball?

I'm confused.