Invisible Exertions

[greenfree]

Virtuoso

The gist of my post is not to delve into all the fine points of the instruction of each and every instructor and scrutinize if it is valid, but simply to try to give people a handle, a possible explanation, why several instructors, like for instance Peter Croker, teach one thing but yet seemingly do something else. A paradox which has intrigued many golfers for a long time.

It's not really a paradox, instructors are human just like students and they have feels and ideas also,( rightly or wrongly) and they are trying to relate a feel or idea of theirs to their students who may or may not relate to that feel or idea the way the instructor does.

 

[Brian Manzella]

To give people some feel for torques of real golfers, shown some measurements of wrist torques taken from 'A THREE DIMENSIONAL KINEMATIC AND KINETIC STUDY OF THE GOLF SWING' , Steven M. Nesbit



"Figure 9 illustrate the alpha component of the torque applied to the grip respectively for the four subjects."

"The subjects exhibited alpha torque profiles that were both unique and consistent among trails revealing a alpha torque “signature” for each subject. Two distinct swing styles were revealed however. The scratch and 5 handicap subjects were “hitters” appearing to exert considerable effort in swinging the club. Their alpha torques increased significantly during the downswing and reached large maximum values at the midpoint of the downswing. These maximum values were maintained until close to impact. The other two subjects were “swingers” with a swing style that was smooth and appeared almost effortless. Their maximum torques were much lower and the curves had smaller variations during the downswing."

Not quite "Swingers" and "Hitters" as per TGM.

Basically Dr. Nesbit, who Mike Finney talked to yesterday and invited to the Symposium, was saying the same thing as Dr. Zick.

You can either NOT add force across the shaft "sort of swinging" or you can "optimize golf swing".

Mandrin, you of all people should know that the literalists will misinterpret Nesbit.

 

[mandrin]

Mandrin, is this former post of yours the same as what your saying in this thread? Excuse my ignorance just trying to grasp what your saying. Is there seperate pure hitting and pure swinging procedures or a combination of the two in various golfswings?

greenfree,

I don't know if there is really a clear definition of either hitting or swinging agreed by all.

In the post you referred to I was trying primarily to show that introducing 'swinging' and 'hitting' into a mechanical model there is way less difference than feel might entice you to think.

The human body/mind /club combination is a rather complex mix of all kind of considerations, but some very general points:

Lead side dominance for swinging versus trail side dominance for hitting.
Early efforts and letting go through impact for swinging and just the opposite for hitting.
Hitting might also include active application of wrist torque through impact zone.

Common sense seems to indicate that optimum is quite likely obtained by soliciting as many muscles as possible in a golf swing so that they work at lowest effort level possible. One could say therefore, contrasting with the pseudo TGM science, that an intelligent mix of the ingredients of both swinging and hitting is likely to be optimum.

 

[greenfree]

greenfree,

I don't know if there is really a clear definition of either hitting or swinging agreed by all.

In the post you referred to I was trying primarily to show that introducing 'swinging' and 'hitting' into a mechanical model there is way less difference than feel might entice you to think.

The human body/mind /club combination is a rather complex mix of all kind of considerations, but some very general points:

Lead side dominance for swinging versus trail side dominance for hitting.
Early efforts and letting go through impact for swinging and just the opposite for hitting.
Hitting might also include active application of wrist torque through impact zone.

Common sense seems to indicate that optimum is quite likely obtained by soliciting as many muscles as possible in a golf swing so that they work at lowest effort level possible. One could say therefore, contrasting with the pseudo TGM science, that an intelligent mix of the ingredients of both swinging and hitting is likely to be optimum.

Thanks for the reply , maybe that's why good players in all sports make it look easy. They get the most with the least as opposed to the least with the most.

 

[mandrin]

It was my understanding of Cochrane/Jorgensen that they looked at the overall amount of work done in accelerating the clubhead from the top of the swing to impact - and concluded, based on assumptions about efficiency and power output per mass of muscle, that there simply isn't enough muscle mass acting directly on the hands and arms to generate the power found in an effective golf swing. In other words, they weren't assuming "big muscle power" because of any particular delivery mechanism - they just couldn't find sufficient muscle mass to produce the power output of a good golf swing anywhere else in the body.

Do you think that through the use of linear joint reaction forces you can identify sufficient muscle mass acting on the club to power a good swing without having to look to the active participation of the largest muscles? Or, do you think that Cochrane/Jorgensen were mistaken and overestimated the amount of muscle mass required?

birly-shirly,

I did some years ago an analysis using both a 2 and a 3 segment math model.

To give some feel let me just show here the conclusions of the analysis for the 2 segment math model.

Conclusions:

The up to 4 horse-power requirement put forward by Cochran et al., needing at least 30 lbs of muscles, working flat-out, to produce it did not take into account the contribution by the linear reaction forces in transferring energy through to the clubhead via the joint-force power. This leaves the door a bit more open for those golfers who feel that they power their swing more with the arms and use the body as a stabilizing platform. It seems to be contradicting to state first that the passive joint forces don't contribute any energy/power to the golf swing and then conclude that it is a significant power source for the golf club segment. It is however only an apparent contradiction/paradox. It is true that the arm/shoulder torque is the principal input for power/energy into the golf swing. It is also true that the power/energy role of the joint force, overall, is zero or neutral. However, their action on each segment, taken separately, is not zero or neutral, and the associated power actually peaks considerably above the muscle power sources. Perhaps intuitively some might feel this to evoke a bit the amplifying effect occurring in a whip when the kinetic energy is flowing into ever smaller mass elements.*

mandrin

 

[mandrin]

Do you think your analysis implies anything other than just the underlying nature of the paradox?

Virtuoso,

Yes and no.

It also clearly suggests the importance at large of invisible exertions in learning and teaching golf.

Many teach golf with instructions from the outside - how it looks. They might be completely wrong.

A true teacher knows things from the inside, feels them in his guts, and knows various ways to explain this 'inside' track.

 

[mandrin]

Mandrin can you clarify the wrist torque?

Is it a torque related to forces around an axis like from elbow to wrist, or is related to uncocking (or the restraint) of the wrist and club handle? I think the latter and most of the high torque is for maintaining lag of the cocked wrist/club.

Thanks.

dbl,

The wrist torque is indeed, as implied, the external torque exerted, by the contraction of wrist(s) muscles, on the butt end of the shaft. It is shown as Torque2 in Fig1b.

There is also a wrist torque in Fig1a, but it is passive and assumed to be generated by the restrained developed by the bone structure once wrists are fully cocked. This is only the case for the first 1/3 of the down swing. From thereon it is a free hinge.

 

[mandrin]

It's not really a paradox, instructors are human just like students and they have feels and ideas also,( rightly or wrongly) and they are trying to relate a feel or idea of theirs to their students who may or may not relate to that feel or idea the way the instructor does.

greenfree,

You are taking a lesson from a instructor teaching you to uncock forcefully the wrists in the down swing

You do as instructed and indeed succeed in doing exactly as being told.

Pity however you failed to make a descent down swing.

The instructor again demonstrates and instructs you once more to really uncock those wrists forcefully.

His swing is a thing of true beauty, smooth, forceful with late release and all.

Again you do as told and again a miserable down swing.

Don't you agree that this might be considered to be a bit of a paradox ?

 

[mandrin]

Not quite "Swingers" and "Hitters" as per TGM.

Basically Dr. Nesbit, who Mike Finney talked to yesterday and invited to the Symposium, was saying the same thing as Dr. Zick.

You can either NOT add force across the shaft "sort of swinging" or you can "optimize golf swing".

Mandrin, you of all people should know that the literalists will misinterpret Nesbit.

Brian,
I am quite surprised at your reaction. There is no danger whatsoever.
You must know that they desperately shy away from any real science.
They would not know what to do with any true scientific information.

 

[greenfree]

greenfree,

You are taking a lesson from a instructor teaching you to uncock forcefully the wrists in the down swing

You do as instructed and indeed succeed in doing exactly as being told.

Pity however you failed to make a descent down swing.

The instructor again demonstrates and instructs you once more to really uncock those wrists forcefully.

His swing is a thing of true beauty, smooth, forceful with late release and all.

Again you do as told and again a miserable down swing.

Don't you agree that this might be considered to be a bit of a paradox ?

Well, okay a bit. but like i said his feel and or ideas may not be right. The instructor that is. Who really knows?

 

[RVArya]

Mandrin,
I am sure you must be aware of Rod White's article "On the efficiency of the golf swing,” Am. J. Phys., 74 1088-1094 (2006), where he clearly shows that application of positive wrist torque degrades the effectiveness of the golf swing and leads to a loss in distance.

A hitter's swing (one who actively employs wrist torques) is less efficient in terms distance and accuracy compared to a swinger (one who depends mainly on centrifugal force)

 

[mandrin]

Mandrin,
I am sure you must be aware of Rod White's article "On the efficiency of the golf swing,” Am. J. Phys., 74 1088-1094 (2006), where he clearly shows that application of positive wrist torque degrades the effectiveness of the golf swing and leads to a loss in distance.

A hitter's swing (one who actively employs wrist torques) is less efficient in terms distance and accuracy compared to a swinger (one who depends mainly on centrifugal force)

RVArya, I have seen it. Thanks for reminding me, I had forgotten all about it.

Essentially simplification of the Lagrange equations for double pendulum model, to make them easier to manipulate analytically, avoiding numerical integration. Dr. Jorgensen already came to that conclusion about positive wrist torque when used early in the down swing. The analysis is indeed very simplified - gravity neglected and constant values for torques - and can't be used to make broad claims about the role of wrist cock in the down swing.

When introducing varying time histories for the torques it becomes another game altogether. I can't right now remember the research paper, dealing with finding the optimum torques in a golf swing, but it showed that the optimum core torque in a golf swing is rather similar in shape to the one I used, shown in Fig2b.

A hitter's swing (one who actively employs wrist torques) is less efficient in terms distance and accuracy compared to a swinger (one who depends mainly on centrifugal force)

Broad sweeping statement for which I would love to see some substantiation. Not based on a simplified simple 2 segment math model using simple constant torque values but based on real measurements with pro type golfers.

 

[dbl]

Thanks Mandrin (and others). I have restudied the analysis and see the methods and implications.

In a subjective way, can you comment on the performance of the stroke with a constant T1 and constant T2...what happens?

 

[Virtuoso]

Ok Mandrin, I'm learning a lot here.

Riddle me this: would the golfing machine gang say that a baseball pitcher is hitting or swinging? Or would they say he has both options at his disposal and could choose?

With your analysis as a guide, one pitcher could say, "I just take a step toward the target and then explode my right elbow outward before my right wrist" (hitting without taking into account internal special torque1)

Another says, "I just relax my arm, uncoil my body and let my arm crack like a whip." (swinging with constant torque1 and free wrist hinge)

Even though we've approached this analysis as if the first pitcher has invisible exersions at T1, are they really that dissimilar? Or am I comparing apples and oranges with golf swing to baseball pitch?

And a related point, my theory would be that you could only "hit" to the extent that you could multiply clubhead velocity more than what centrifugal force (or the kinetic chain) had already done for you....which I think would be the rarest of things.

 

[greenfree]

Ok Mandrin, I'm learning a lot here.

Riddle me this: would the golfing machine gang say that a baseball pitcher is hitting or swinging? Or would they say he has both options at his disposal and could choose?

With your analysis as a guide, one pitcher could say, "I just take a step toward the target and then explode my right elbow outward before my right wrist" (hitting without taking into account internal special torque1)

Another says, "I just relax my arm, uncoil my body and let my arm crack like a whip." (swinging with constant torque1 and free wrist hinge)

Even though we've approached this analysis as if the first pitcher has invisible exersions at T1, are they really that dissimilar? Or am I comparing apples and oranges with golf swing to baseball pitch?

And a related point, my theory would be that you could only "hit" to the extent that you could multiply clubhead velocity more than what centrifugal force (or the kinetic chain) had already done for you....which I think would be the rarest of things.

How about a baseball batter instead of a pitcher.

 

[Brian Manzella]

GEEZ.........

THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!

NONE.

Nonions.

Zilch.

Please let;s call it something else.

Because if this thread with a smart scientist doesn't kill it dead, we will in Scottsdale.

 

[birly-shirly]

birly-shirly,

I did some years ago an analysis using both a 2 and a 3 segment math model.

To give some feel let me just show here the conclusions of the analysis for the 2 segment math model.

Conclusions:

The 3 to 4 hp requirement put forward by Cochran et al., and the 2 hp requirement asserted by Jorgensen, contrast with the 1hp peak power requirement following from my analysis. It appears therefore that the 32 lb of lean muscles required by Jorgensen's analysis could by be cut by about half. This leaves the door a bit more open for those golfers who feel that they power their swing more with the arms and use the body as a stabilizing platform. If the analysis above had been done with my 3 segment model it is to be expected that the 1 hp requirement is still further going to reduce. Perhaps will do eventually, it requires a fair amount of work.



mandrin

Thanks Mandrin. It sounds like our understanding of the efficiency of human movements is developing considerably with time.

As for the terminology issue - I'd be relaxed about that. Isn't TGM-style "pure hitting" a dead-letter now? If not everyone accepts that, I still don't think that should prevent the terminology being freed up for something more useful. Like this.

 

[birdie_man]

Thanks for the reply , maybe that's why good players in all sports make it look easy. They get the most with the least as opposed to the least with the most.

DO they all make it look easy though?

Results-wise maybe.

But you must be talking about swing and overall physical (behavioural) appearance, no? (i.e. Ernie Els, Sam Snead, G Ogilvy, Couples, etc.)

There are people who make it LOOK less easy...yes?

Common sense seems to indicate that optimum is quite likely obtained by soliciting as many muscles as possible in a golf swing so that they work at lowest effort level possible. One could say therefore, contrasting with the pseudo TGM science, that an intelligent mix of the ingredients of both swinging and hitting is likely to be optimum.

Broad sweeping statement for which I would love to see some substantiation. Not based on a simplified simple 2 segment math model using simple constant torque values but based on real measurements with pro type golfers.

That's the way mandrin.

Virtuoso,

Yes and no.

It also clearly suggests the importance at large of invisible exertions in learning and teaching golf.

Many teach golf with instructions from the outside - how it looks. They might be completely wrong.

A true teacher knows things from the inside, feels them in his guts, and knows various ways to explain this 'inside' track.

'What' vs. 'How', correct?

"Both are valid ways to swing a club. Probably also a matter of personality. A controlling/aggressive person will be better off hitting."

Madrin you are slipping.

mandrin you haven't responded to mb yet.

THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!
THERE IS NO TGM DEFINED HITTING IN TOURNAMENT GOLF—NONE!

NONE.

Nonions.

Zilch.

Please let;s call it something else.

Because if this thread with a smart scientist doesn't kill it dead, we will in Scottsdale.

Blam blam blam with a shotgun. (and then a neck snap)

Thanks Mandrin. It sounds like our understanding of the efficiency of human movements is developing considerably with time.

As for the terminology issue - I'd be relaxed about that. Isn't TGM-style "pure hitting" a dead-letter now? If not everyone accepts that, I still don't think that should prevent the terminology being freed up for something more useful. Like this.

I must admit...I am still a little hesitant on the "hitting/swinging" terms (as absolutes, just how I have written them) however they are used. They seem prone to misinterpretation.

What I mean is...even if you explain that everyone does both to some degree, when the terms written as absolutes ("hitting/swinging" or "a hitter/a swinger") I can see people explaining in absolutes.

What about "torque" terminology? (as Brian has used in the past)

Just an idea.

...

Good thread- thanks mandrin.

This still needs to percolate a little more.

(I am still percolating, that is)

 

[greenfree]

Birdieman, there is people who make it look less easy for sure and i know from first hand experience..lol.

 

[birdie_man]

Haha.

Ya been there done that no doubt.

But what I meant was...

There are still the Floyds...the Palmers...even the Woods' or Hogans perhaps. (don't think you would call either of em real "smooth")

So are you talking "smooth"...or are you talking "proficient"?