3D motion capture and the resulting measurements......

[SteveT]

Steve is not a golf teacher. And he sounds just like it—a lot.

Stick to science SteveO.

You're right, Brian, I don't pretend to be a teacher, but neither do I pretend to know the science... I KNOW the science.

However, I did try to be a golfswing teacher, but I only had one student... ME!!!!

Man-o-man did I struggle.... from reading the golden oldies like Jones to Hogan and then to all the "golf my way" delusionary nonsense. You know what I think of TGM. Then I found true "science" starting with SPS and Dr. David Williams and Science & Golf I, II, III, IV... then along came SLAP and LAWs which were decent applications of the science. Then I was immersed in launch monitors and various kinetic analyses by university professors.

Then I gave up and accepted my physical limitations and capitulated to age. Now I seldom golf, but I'm still a scientific expert of sorts. Heed what I say.

(p.s. I hope you don't tell your scientific team to stick to science, and to leave the black art of teaching to you.)

 

[SteveT]

You are so right with this SteveT. Only want to ad that we have to understand it as a two way chain. From the ground to the club head and then back from the club head to the ground.

If we miss the first one, we loose power, if the last one, we loose our balance.

Interesting concept about reverse sequencing for balance. Could you expand on that, and how you view students struggling with balance... because balance involves the positioning of the body center of mass located near the navel. I have my views, but since you brought up the topic, could you enlighten us on balance factors.

 

[SteveT]

Correct Pic:

Now that the orientation of the back of the left hand is clarified, could you please explain what the dark green line called #4 (Left Arm to Chest) represents? I suspect it has something to do with going "normal".

 

[TeeAce]

Interesting concept about reverse sequencing for balance. Could you expand on that, and how you view students struggling with balance... because balance involves the positioning of the body center of mass located near the navel. I have my views, but since you brought up the topic, could you enlighten us on balance factors.

I don't put so much attention for the center of the mass, I rather look at the the forces and counter forces. Things we can't really see, but what we have to understand. When we understand to what direction the mass of the club head is going and where the mass of the hands are going (all that I call outer circle) we can understand better what kind of action we need to have in our body to stabilize that by opposite forces. For example when hands and club head is going down, the work in our body has to be up, even the result is that it stays steady.

 

[johnnymarlboro]

In TGM speak isn't the #4 in the picture the #4 accumulator?

 

[SteveT]

I don't put so much attention for the center of the mass, I rather look at the the forces and counter forces. Things we can't really see, but what we have to understand. When we understand to what direction the mass of the club head is going and where the mass of the hands are going (all that I call outer circle) we can understand better what kind of action we need to have in our body to stabilize that by opposite forces. For example when hands and club head is going down, the work in our body has to be up, even the result is that it stays steady.

I think I understand what you mean by 'balance'. There are two states of balance... static balance and dynamic balance, and both occur in the golfswing. The science of 'Dynamics' must also include the study of 'Statics' to put kinetics and kinematics in proper perspective. It's complicated, but if you understand these sciences everything becomes clearer. The problem of course is to measure everything so we are talking apples to apples and not apples to feelings.

 

[OLIVER1]

I think I understand what you mean by 'balance'. There are two states of balance... static balance and dynamic balance, and both occur in the golfswing. The science of 'Dynamics' must also include the study of 'Statics' to put kinetics and kinematics in proper perspective. It's complicated, but if you understand these sciences everything becomes clearer. The problem of course is to measure everything so we are talking apples to apples and not apples to feelings.

Steve,
I'm loathe to simplify things in this fashion, but as I'm not a scientist...
Do you think there's any scientific merit in the catchall that, barring vertigo or other inner-ear imbalances, good motions and sequencing will automatically make both static and dynamic balances optimal?

 

[SteveT]

Steve ....... Do you think there's any scientific merit in the catchall that.... good motions and sequencing will automatically make both static and dynamic balances optimal?

"good" and "optimal"... of course... can't beat that!!!

However, it's a tad more complicated than that because you have to track the body center of mass and the influence of forces in the body and at the ground. When Brian is applying his "business" on the student's body, he's manipulating the body CofM through proper positioning. He's a "hands-on" golf scientist so to speak ... because when words of explanation fail, you gotta grab and shake the student!!!

 

[OLIVER1]

"good" and "optimal"... of course... can't beat that!!!

However, it's a tad more complicated than that because you have to track the body center of mass and the influence of forces in the body and at the ground. When Brian is applying his "business" on the student's body, he's manipulating the body CofM through proper positioning. He's a "hands-on" golf scientist so to speak ... because when words of explanation fail, you gotta grab and shake the student!!!

So to paraphrase: No?

 

[SteveT]

So to paraphrase: No?

No... not until you measure to determine what is optimal... and defining what "good" motions entail.

 

[OLIVER1]

No... not until you measure to determine what is optimal... and defining what "good" motions entail.

This is like playing snakes and ladders...

 

[SteveT]

This is like playing snakes and ladders...

Snakes and ladders... versus Monopoly...

 

[drewyallop]

I totally agree with you. The measuring points are different, the definitions of axis and some directions are different and that way we can't say that one is right (specially in rotation speeds) and one is wrong.

What I can say about measurements of 4DSwing, we decided to measure the shoulder rotation around the vertical axis so we can see the rotation from the top down camera also. Another thing is that we measure shoulders from outer part of shoulder joints and not from the spine, and it gives also different results. In few weeks we gonna include the rotation speed also around the spine, but it seems not much difference in results.

3Dmeasurement is something I can call really challenging to define. It feels simple at beginning when we are used to see and think like we do, but gets more complicated when going deeper to that world. For example spine is not rigid and it bends to many directions and to define how to measure it really well "around the spine angle" there is no really simple solution. Around the lower spine or upper part of that will also give different numbers and even to define what is tilt and what is forward bend is quite impossible when everything is changing all the time.

Those are the reasons we got so many other graphs like lateral speeds from different joints, because sometimes those are more informative than pure rotations. The main point is still that whatever system we use, we have to understand how the measurements are defined and only compare apples to apples, not to oranges. When we learn to read one systems graphs and compare those from player to player, we can get the benefits out of them to help people getting better and that's the main goal we all should have. That way we can see if the deceleration of the shoulder speed for example is caused by real deceleration or because the change of moving direction when right shoulder drops and pops up later on.

Just a wild-assed thought from the uninformed: why not put accelerometers on the body parts in question. Or maybe that is done now - don't know.

 

[drewyallop]

I totally agree with you. The measuring points are different, the definitions of axis and some directions are different and that way we can't say that one is right (specially in rotation speeds) and one is wrong.



What I can say about measurements of 4DSwing, we decided to measure the shoulder rotation around the vertical axis so we can see the rotation from the top down camera also. Another thing is that we measure shoulders from outer part of shoulder joints and not from the spine, and it gives also different results. In few weeks we gonna include the rotation speed also around the spine, but it seems not much difference in results.



3Dmeasurement is something I can call really challenging to define. It feels simple at beginning when we are used to see and think like we do, but gets more complicated when going deeper to that world. For example spine is not rigid and it bends to many directions and to define how to measure it really well "around the spine angle" there is no really simple solution. Around the lower spine or upper part of that will also give different numbers and even to define what is tilt and what is forward bend is quite impossible when everything is changing all the time.



Those are the reasons we got so many other graphs like lateral speeds from different joints, because sometimes those are more informative than pure rotations. The main point is still that whatever system we use, we have to understand how the measurements are defined and only compare apples to apples, not to oranges. When we learn to read one systems graphs and compare those from player to player, we can get the benefits out of them to help people getting better and that's the main goal we all should have. That way we can see if the deceleration of the shoulder speed for example is caused by real deceleration or because the change of moving direction when right shoulder drops and pops up later on.

Just a wild-assed thought from the uninformed: why not put accelerometers on the body parts in question. Or maybe that is done now - don't know.

 

[dschultz6072]

Steve,
I'm loathe to simplify things in this fashion, but as I'm not a scientist...
Do you think there's any scientific merit in the catchall that, barring vertigo or other inner-ear imbalances, good motions and sequencing will automatically make both static and dynamic balances optimal?

Isn't JB Holmes struggling right now after brain surgery? Pretty sure he could hit a golf ball OK before.