Is Lag from the left shoulder through impact possible?

Status
Not open for further replies.
I realize you're saying there is lag or nonaxial force resolution "somewhere"; I'm saying Brian's answer was limited to "near impact" (his answers numbered 1 and 2).

Wrong.

I am saying the axial force produces swing speed all the way as long as you keep turning that shoulder. The shoulder is NOT the swing center. THE AXIAL FORCE.

The swing model used in Miura's paper doesn't have a left shoulder, so when the arm and the shaft are inline, the shaft points at the swing center. For a human golfer, the shaft points at the left shoulder when the arm and the shaft is inline.

I am fully aware that this is just a 2D projection.
 
Last edited:
Let's just say that you've got the wrong idea about my ideas.

Either I have turned into an incredible poor writer or you haven't used your reading skills. Either way I see no point in trying to clarify matters any further.

I have no idea about your ideas I can only read what you write.
 

natep

New
I'm not sure I understand him either.

Bernt, are you saying that because the left shoulder is offset and in front of the center of rotation, that as long as the left shoulder is moving its applying a forward, targetward, pulling force on the shaft, even when the shaft is in line with the left arm?
 
G
Quick Answer:
The something I "spotted" was a principle - I've seen it so many times in my studies. In a previous post I called it "isolationism" and it's different in many ways than Finite element method - which doesn't really apply in this context - let me explain. When you have an expert from a certain field i.e. scientist, engineer, chiropractor, biologist, etc. and they use their area of expertise to make a statement on another field i.e. movement, they will observe a fact, then make a conclusion which seems obvious, WHILE ignoring an ESSENTIAL fact of the field they don't specialize in.

When I said you can't take a part of the swing and isolate it without understanding the parts around it, here's the broad explanation of that. Knowledge isn't created in a vacuum, it's created in a context, that context includes "everything", when new facts (let's keep it simple here - and call them major facts) arise it changes the entire context of your knowledge base - why? because it's all related.

How can these "scientist" get things wrong? (Keep in mind - I'm not saying everything that Brian has brought up is wrong - sure I saw one thing and I saw the principle involved, and my post labeled Free Guidance was to say "you better be careful otherwise you're going to have some real problems if you're putting all your money on the scientists".) I'll describe one large of many categories of these mistakes, in regards to the principle, which is the difference between observation of the movement as opposed to implementation of the movement.

Examples (fictional - to clarify and simplify the issue):
Scientist studies the down the line view of the top players in the world - notice that they don't stay on the same plane - that they shift up at 1/2 way back to a steeper plane. Tells his students - at half way back you need to increase the angle from 30 degrees to 50 degrees, as every pro does this. Not realizing that the pro(s) aren't trying to shift planes- they are making an effort to move in one plane on the backswing and anatomical issues create shifting.

Scientist studies backswing lengths for hand travel by taking high speed video - determines that top pros all take it to point A, all amateurs only take it to point B - instructs students to take their hands to Point A before starting the downswing. Not realizing that pros are only trying to take their hands to point A minus 6 inches, the final 6 inches is momentum carrying them to Point A even though the player as already initiated the downswing.

Let's go to your paragraph - I'm going to save myself some time and just give the essence of what I see. Scientist- "Nothing after the ball leaves the clubface affects it's flight - so what you do in the follow-through doesn't matter". "Right before impact there is no lag pressure - so you don't need to worry about that". "There is nothing you can do once the club is released". "So, really we just need to figure out on a procedural level what to do up until the point of release, becuase after that you can't control it". Now, it boggles my mind, assuming someone has played this game for over a couple of months how you wouldn't intuitively understand that key aspects of attention through impact, through the follow-through and finish - are critical elements of the mind. On a more scientific level the "scientist" who doesn't understand how movement takes place and how the Brain works, has missed the ESSENTIAL nature of movement. That it takes into account the past, present and FUTURE. Memory is a tool to predict the future. Every time you move you are making a prediction based on your prior experiences. So there is a focus on the future, those items past the time where your scientist said "it doesn't matter", because that controls the past and vica versa.

What's happening and What you try to do - are two completely different things.

Very interesting mike. I have been casually reading recent brain research that asserts that the brain reacts to a stimulus before we are aware of it. For example our concious act to pick up an object is preceded by "pick up" brain activity of which we are not aware. Aside from the implications for free will how do you think this fits with swing theory?
 
I am not very interested in non-axial forces near impact either. The lag pressure I have been pressing forward here is 100% carried by axial force. It was the whole point of starting the thread. How can you not have seen that?

I'm not sure I understand him either.

Bernt, are you saying that because the left shoulder is offset and in front of the center of rotation, that as long as the left shoulder is moving its applying a forward, targetward, pulling force on the shaft, even when the shaft is in line with the left arm?

exactly, natep.

As simple as that.

Now I don't know what BerntR's question is.

Don't these forces have different vectors? Is Axial force along the shaft--a vector pointing where the but end of the club is pointing?

Wouldn't a "forward, targetward, pulling force on the shaft" be across the shaft and not axial?

Or is the question what proportion of each force is there at impact because the left shoulder is in front of the shaft?

I may be kind of slow, but would like to understand the nuance of the point.
 
Last edited:
isolationism is the downfall of the current researchers???.....

was isolationism a problem for cochran and stobbs?
homer kelley?

come on, man.....we're just trying to dig and use the latest tools.....3D modeling and 3D measuring surely trumps the 60s......please give us credit for not getting sucked down a rabbit hole....we were already sucked down one in the 80s
 

Brian Manzella

Administrator
This thread and the the current "hips"thread is the reason nobody else has a forum this popular.

I have been away for a day or two, and will provide some answers on these "theories" later tomorrow.
 
Not arguing, or commenting except that - make sure you are using the term properly - Radial Force IS up the shaft.

In my world radial force is towards the swing center. If it's also up the shaft the golfer is either flipping or has stopped turning the shoulders so left shoulder has become the swing center.

Axial force, however, is up the shaft.

I don't claim monopoly to defining terms here. As long as we agree what the terms mean, and as long as we have enough of them to differentiate between e.g. what goes up the shaft and what goes towards the swing center I am OK with it.
 
1 Yes, axial force is along the shaft.

2 When you pull, you will create axial forces and not shear forces.

3 The question (to me anyway) is how much the axial force pulls forward and how much it pulls inward.

You may want to google axial forces. It is very commonly used in construction. In construction you typically consider axial forces (push and pull) as well as shear forces (across).

Now I don't know what BerntR's question is.

1: Don't these forces have different vectors? Is Axial force along the shaft--a vector pointing where the but end of the club is pointing?

2: Wouldn't a "forward, targetward, pulling force on the shaft" be across the shaft and not axial?

3: Or is the question what proportion of each force is there at impact because the left shoulder is in front of the shaft?

I may be kind of slow, but would like to understand the nuance of the point.
 
I have no idea about your ideas I can only read what you write.

I was a bit harsh back there. I apologize.

But you were ascribing me assumptions and errors that I don't agree with.

It looks to me like you have your own angle. It could be interesting if you put it down in your own words instead of as foot note to mine.
 
3 The question (to me anyway) is how much the axial force pulls forward and how much it pulls inward.

You may want to google axial forces. It is very commonly used in construction. In construction you typically consider axial forces (push and pull) as well as shear forces (across).

Thank you. #3 clears it up more for me.

I quickly Googled this, but didn't find anything for the brief time I looked. My next question is at what point does an axial force become a shear force? If shear force is opposing parallel forces or in this case "across the shaft"(tangential--thanks, MikeO), then would you say any time the force is not 90* to the shaft it is an axial force?

Thanks again for the clarification.
 
Last edited:
In my world radial force is towards the swing center. If it's also up the shaft the golfer is either flipping or has stopped turning the shoulders so left shoulder has become the swing center.

Axial force, however, is up the shaft.

I don't claim monopoly to defining terms here. As long as we agree what the terms mean, and as long as we have enough of them to differentiate between e.g. what goes up the shaft and what goes towards the swing center I am OK with it.

I knew when I posted that - it wasn't precise, it was posted in the context of either tangential OR radial in a general way, so you're comment is well taken. Now, if you Google Radial Force - you get a simple mechanical picture of say a bicycle wheel with spokes and the radial force is the one that goes up the "radius" towards the center - easy enough. What would you define as the center of the swing and why? A two sentence answer works for me - doesn't have to be detailed - just want to see where your generally coming from on this.
 
Last edited:
Thank you. #3 clears it up more for me.

I quickly Googled this, but didn't find anything for the brief time I looked. My next question is at what point does an axial force become a shear force? If shear force is opposing parallel forces or in this case "across the shaft", then would you say any time the force is not 90* to the shaft it is an axial force?

Thanks again for the clarification.

Flip down to p 101 here : Understanding Axial Force Shear Force and Bending Moment Diagrams

It may be difficult to understand the figures but it's the best I can find.

An axial force is strictly defined to run axially in the shaft or beam or whatever. If you have some of everything you may have to decompose to find the axial component.
 
isolationism is the downfall of the current researchers???.....

Mike,
I was merely saying that "just because a scientist has discovered a fact", it's easy to have it presented in a way that isn't correct depending on how you use it or understand it and the context that's relevant. A car bumper can kill you or save you, just depends on your perspective. Could it be a downfall- absolutely.

was isolationism a problem for cochran and stobbs? homer kelley?

As I mentioned before I'm not really interested in "who", or "them".


come on, man.....we're just trying to dig and use the latest tools.....3D modeling and 3D measuring surely trumps the 60s......please give us credit for not getting sucked down a rabbit hole....we were already sucked down one in the 80s
I'm describing another rabbit hole not to go down. I've said on more than one occasion that I love the search for new knowledge, new ideas that you guys are trying to uncover.
 
Last edited:
G

Very interesting mike. I have been casually reading recent brain research that asserts that the brain reacts to a stimulus before we are aware of it. For example our concious act to pick up an object is preceded by "pick up" brain activity of which we are not aware. Aside from the implications for free will how do you think this fits with swing theory?
Wish I could answer your question with the detail and precision that it deserves - maybe in 20 years. Feedforward neural activity (planning, predicting, anticipating) vastly out numbers feedback neural activity (sensory feedback, monitoring) in the brain. However, predicting, anticipating is based on your prior experiences i.e. memory. You become a better predictor if you have more experiences to draw from, which means that potentially you'll be better the more you experiment/diversify your experiences/movement - as opposed to working on being consistent and limiting your experiences.
 
Last edited:
I knew when I posted that - it wasn't precise, it was posted in the context of either tangential OR radial in a general way, so you're comment is well taken. Now, if you Google Radial Force - you get a simple mechanical picture of say a bicycle wheel with spokes and the radial force is the one that goes up the "radius" towards the center - easy enough. What would you define as the center of the swing and why? A two sentence answer works for me - doesn't have to be detailed - just want to see where your generally coming from on this.

Somewhere in the spine, between the belly button and the shoulders. But I think you might get another answer if you looked at it from the club and not the golfer. The geometry has aspects of a triple pendulum - left shoulder, left arm, club. Matters are complicated further by differerent planes being involved, and perhaps they are not really planes either, just close enough to deceive us.

So the swing center label is certainly a simplification here. But one thing I know is that when you pull from a moving shoulder, the pull can be decomposed into one component that is at right angles to the motion and only changes direction, and one component that has the same direction as the motion and creates speed.
 
Somewhere in the spine, between the belly button and the shoulders. But I think you might get another answer if you looked at it from the club and not the golfer. The geometry has aspects of a triple pendulum - left shoulder, left arm, club. Matters are complicated further by differerent planes being involved, and perhaps they are not really planes either, just close enough to deceive us.

So the swing center label is certainly a simplification here. But one thing I know is that when you pull from a moving shoulder, the pull can be decomposed into one component that is at right angles to the motion and only changes direction, and one component that has the same direction as the motion and creates speed.
OK, I like that.


But one thing I know is that when you pull from a moving shoulder
What's the context here? Everyone's shoulder is moving through 3D space. Since it's attached to the arm - it's going to pull whether you feel it or not. I guess I need more elaboration. Are you saying that this is a dominant feel for you?
 
Status
Not open for further replies.
Top