Release

[Dariusz J.]

Yep, very good drawings, Mandrin. It explains why the release is more effective when the F force vectors are acting along a curved line at the impact zone. Swinging left with the grip matches this scenario pretty well (the curved line will be angled, i.e. not only up but up and to the left of the target line). It sort of explains also why someone who is not a flipper may benefit from it as well if he is able to "direct" the force F properly.

I think you are well prepared to write a book about golf swing geometry and explain all forces acting in the swing in a friendly way so that laics as me would understand everything better.

Cheers

 

[mandrin]

Yep, very good drawings, Mandrin. It explains why the release is more effective when the F force vectors are acting along a curved line at the impact zone. Swinging left with the grip matches this scenario pretty well (the curved line will be angled, i.e. not only up but up and to the left of the target line). It sort of explains also why someone who is not a flipper may benefit from it as well if he is able to "direct" the force F properly.

I think you are well prepared to write a book about golf swing geometry and explain all forces acting in the swing in a friendly way so that laics as me would understand everything better.

Cheers

Dariusz,

You are quick to see the essential and it is obvious that you have done your homework. On a forum with a + 7000 membership you seem to be perhaps a rare bird. Indeed for such a large discussion group seemingly open to new ideas and science it is rather intriguing this lack of interest.

You use the expression “drawings”. It made me wonder if some might view them indeed simply as drawings. However they are not quite drawings. They are graphical presentations mathematically driven and generated by the two differential equations governing the dynamics.

 

[Dariusz J.]

Dariusz,

You are quick to see the essential and it is obvious that you have done your homework. On a forum with a + 7000 membership you seem to be perhaps a rare bird. Indeed for such a large discussion group seemingly open to new ideas and science it is rather intriguing this lack of interest.

You use the expression “drawings”. It made me wonder if some might view them indeed simply as drawings. However they are not quite drawings. They are graphical presentations mathematically driven and generated by the two differential equations governing the dynamics.

Mandrin,

Thaks for kind words and I apologize for "the drawings". Looking at the two equations the name"graphic representation" is appropriate

I also wonder why so important a thing may evoke so little discussion on the Forum. This is pure golf science.

Cheers

 

[mandrin]

Having looked at some factors regarding release it is interesting to look at retaining action prior to release. This concerns primarily the angle between lead arm and club.

A simple setup - 250 gram point mass, arm length 1m, inner hub .6 m and constant hub torque of 30 N. Figs 1 and 2 show the result.

Notice the negative torque for the first 0.1 sec (brown, Fig1). This causes the initial bending of the shaft especially for a dynamic transition action by the golfer.

The torque required to maintain the angle increases very rapidly and gets quickly too big for a human golfer to handle relying to do so on a potentially ‘feeble’ wrist retaining torque.

As a result the club likely at some critical threshold suddenly “snaps out" and away from the wrist control action exerted by the golfer and release action of the club is underway.

 

[Ringer]

How about "the last sequence involved in a deceleration due to extension".

 

[jmessner]

Having looked at some factors regarding release it is interesting to look at retaining action prior to release. This concerns primarily the angle between lead arm and club.

A simple setup - 250 gram point mass, arm length 1m, inner hub .6 m and constant hub torque of 30 N. Figs 1 and 2 show the result.

Notice the negative torque for the first 0.1 sec (brown, Fig1). This causes the initial bending of the shaft especially for a dynamic transition action by the golfer.

The torque required to maintain the angle increases very rapidly and gets quickly too big for a human golfer to handle relying to do so on a potentially ‘feeble’ wrist retaining torque.

As a result the club likely at some critical threshold suddenly “snaps out" and away from the wrist control action exerted by the golfer and release action of the club is underway.

Mandrin,

Not to threadjack too much, but can you extend this to determine the forces placed on the hands by the shaft during the swing? I'm assuming that the relative stiffness of the shaft (especially at the butt end) would cause a different loading profile on the hands at the transition which could account for the difference in shaft feel for players and of course it would also depend on the particular golfers' swing dynamics. By my thinking, swinging a steel pipe would produce a very sharp (fast loading) feel, whereas a flexible shaft (think whippy tempomaster) would produce a smoother (slow loading) feel.

Jay

 

[James Marshall (Hogan1953)]

The 'straight line golfer' applies a linear pulling force. This force can be decomposed into a couple and a linear force as shown in Figs 1a and 1b. The force F has hence two effects. It accelerates the club along the line of application of the force and moreover it exerts a torque on the club trying to align the club with the force vector.

However as soon as the clubhead drops below the horizontal the couple acting on the club reverses in sign and starting to slow down the angular releases motion, Fig1b. How can we prevent this from happening? Just as in a real golf swing by constantly changing the force vector's direction so as to maintain an appropriate angle between club and force F.

The force F, by constantly changing direction, is much more efficient creating a rapidly accelerating angular release motion. This is illustrated in Figs 2 and 3. This brings us to the subject of effective swing radius - perhaps matter of analysis for another post, i.e., if there is at least evidence of some minimum interest.

Mandrin,

Does this imply that straigthening the right arm at the right time is an effective way of changing the direction of the force and therefore adding energy to the motion of the club?

James

 

[mandrin]

Mandrin,

Not to threadjack too much, but can you extend this to determine the forces placed on the hands by the shaft during the swing? I'm assuming that the relative stiffness of the shaft (especially at the butt end) would cause a different loading profile on the hands at the transition which could account for the difference in shaft feel for players and of course it would also depend on the particular golfers' swing dynamics. By my thinking, swinging a steel pipe would produce a very sharp (fast loading) feel, whereas a flexible shaft (think whippy tempomaster) would produce a smoother (slow loading) feel.

Jay

Jay,

Experienced golfer with a dynamic transition can indeed develop a considerable torque at the transition. The torque shown is quite a bit below the value which can occur in an actual dynamic transition where there is a rapid change in direction which is not accounted for in my simple model, but could be included, if desired.

It is understandable that this feeling of loading the shaft has led HK and many, many others to instruction/theories in which it is claimed/thought that the initial bending of the shaft helps create clubhead speed by unlashing this bending energy through impact. Yet this does not occur in a golf swing.

Feeling is a very personal thing but I would guess that your idea is indeed quite correct for the transition. During the remaining of the down swing it is however a very complicated matter of interaction of the dynamic action of the club and the muscular activity of the hands often due to the instinctive hit impulse.

I have seen scientific studies in the past where gauges where placed at different positions on the grip and/or golfers hands but only recall that measurements were very different when comparing pros and amateurs and moreover usually characteristic for each golfer.

 

[rwh]

There is usually a mixture of referring to release as how release occurs, the entity being released and the timing of the release.

Experienced golfers will likely agree that an accurate release can’t be triggered consciously and has to happen by itself. So what is it that might be causing this release to happen by itself? (emphasis added)

mandrin,

Golf books written several decades ago (e.g., Joe Dante's The Four Magic Moves to Winning Golf) advocated not trying to actively move the arms and hands from the top but, instead, to let the pivot bring them down whereupon COAM (conservation of angular momentum) automatically produces the release that allows the clubhead to catch up to the hands.

I don't pretend to understand the science, but - to a layman like myself - it sounds like a good explanation and, in my experience, it seems to work rather nicely.

Does COAM explain what I call a "passive" release (passive from the point of view that I don't try to do anything with the arms and hands)?

 

[Bronco Billy]

mandrin,

Golf books written several decades ago (e.g., Joe Dante's The Four Magic Moves to Winning Golf) advocated not trying to actively move the arms and hands from the top but, instead, to let the pivot bring them down whereupon COAM (conservation of angular momentum) automatically produces the release that allows the clubhead to catch up to the hands.

I don't pretend to understand the science, but - to a layman like myself - it sounds like a good explanation and, in my experience, it seems to work rather nicely.

Does COAM explain what I call a "passive" release (passive from the point of view that I don't try to do anything with the arms and hands)?

No

 

[mandrin]

Mandrin,

Does this imply that straigthening the right arm at the right time is an effective way of changing the direction of the force and therefore adding energy to the motion of the club?

James

James,

Some instruction wants you to extend the clubhead through and beyond impact out towards the target. Anything along this nature, in my opinion, does not make up for a natural and sound golf swing.

Brian, I think, is strongly advocating swinging left beyond impact. Another teacher who is very strong on swinging left is Mark Evershed. A natural swing, especially through impact, should be on-plane and hence goes inwards and upwards, beyond impact.

A rather different move, re to swinging sharply inwards, but mathematically equivalent, is to stand up through impact such as done by Laura Davis. They can both be analyzed as causing a ‘shortening of effective swing radius’. It does not take all that much to gain a few percent in club head speed.

Curving inwards/upwards is most effective pumping energy into the swing when the club has obtained high speed hence, primarily, just before impact. Perhaps when you will hear now on TV a comment that a golfer is snapping his knee(s) straight through impact, it might take on perhaps a different meaning.

James, the trail arm per se can push in various ways. Perhaps it is better to concentrate on continuing to pivot through and beyond impact. Another useful idea perhaps is to keep the lead upper arm glued to the chest.

You might want to play around for fun with doing part swings with only two thoughts in mind – back swing, trail elbow slides backwards along trail hip and mirror like for through swing - lead elbow slides back along lead hip.

 

[mandrin]

mandrin,

Golf books written several decades ago (e.g., Joe Dante's The Four Magic Moves to Winning Golf) advocated not trying to actively move the arms and hands from the top but, instead, to let the pivot bring them down whereupon COAM (conservation of angular momentum) automatically produces the release that allows the clubhead to catch up to the hands.

I don't pretend to understand the science, but - to a layman like myself - it sounds like a good explanation and, in my experience, it seems to work rather nicely.

Does COAM explain what I call a "passive" release (passive from the point of view that I don't try to do anything with the arms and hands)?

rwh,

I agree that Dante’s book is one of only a few golf books with interesting information for the serious golf student. Whereas however it all sounds indeed very good and scientific it is not really correct to use the term COAM. But it is a mistake made by everybody who invokes this concept re to the golf swing.

Frequently one refers for an explanation to diver or to a skater. These examples are not valid as a model for comparison to a golfer. The skater, for instance, starts his pirouette with a certain amount of energy/momentum which is largely conserved there being little friction between ice and skates.

The golfer however does not conserve any angular momentum. On the contrary, he definitely has to work hard to generate it all from scratch in the down swing. Moroever it is not COAM which initiates the release but the buildup of a large centrifugal inertial force which suddenly can’t be retained anymore by the golfer.

But that does not diminish in any way the value of the golf instruction in Dante’s book. It is imo on a similar level as HK’s efforts for the advancement of golf. Intuitively Dante’s instruction sounds and feels good and produces correct results and that is all that matters for a golfer.

 

[flapro]

release comes from relaxed arms, hands, and shoulders coupled with achieving a tray position at the top. The tray position coupled with a proper pivot(ala Brian's pivot) stores tremendous power which when brought down into impact from the inside, releases everything without the player having to do anything.
The less thought one has about release the better.
Its a natural result and cannot be manufactured

 

[tongzilla]

James,

Some instruction wants you to extend the clubhead through and beyond impact out towards the target. Anything along this nature, in my opinion, does not make up for a natural and sound golf swing.

Brian, I think, is strongly advocating swinging left beyond impact. Another teacher who is very strong on swinging left is Mark Evershed. A natural swing, especially through impact, should be on-plane and hence goes inwards and upwards, beyond impact.

A rather different move, re to swinging sharply inwards, but mathematically equivalent, is to stand up through impact such as done by Laura Davis. They can both be analyzed as causing a ‘shortening of effective swing radius’. It does not take all that much to gain a few percent in club head speed.

Curving inwards/upwards is most effective pumping energy into the swing when the club has obtained high speed hence, primarily, just before impact. Perhaps when you will hear now on TV a comment that a golfer is snapping his knee(s) straight through impact, it might take on perhaps a different meaning.

James, the trail arm per se can push in various ways. Perhaps it is better to concentrate on continuing to pivot through and beyond impact. Another useful idea perhaps is to keep the lead upper arm glued to the chest.

You might want to play around for fun with doing part swings with only two thoughts in mind – back swing, trail elbow slides backwards along trail hip and mirror like for through swing - lead elbow slides back along lead hip.

Nice to hear you finally giving some practical advice!

 

[mandrin]

Release comes from relaxed arms, hands, and shoulders coupled with achieving a tray position at the top.

The tray position coupled with a proper pivot stores tremendous power which when brought down into impact from the inside, releases everything without the player having to do anything.

The less thought one has about release the better. Its a natural result and cannot be manufactured

flapro,

Nice metaphore, but it does not have any meaning. Power is generated not by any particular postion of body parts but rather manufactured by a coordinated effort of many contracting muscles.

 

[mandrin]

Nice to hear you finally giving some practical advice!

tongzilla,

Nice to see you are learning something.

 

[James Marshall (Hogan1953)]

James,

Some instruction wants you to extend the clubhead through and beyond impact out towards the target. Anything along this nature, in my opinion, does not make up for a natural and sound golf swing.

Brian, I think, is strongly advocating swinging left beyond impact. Another teacher who is very strong on swinging left is Mark Evershed. A natural swing, especially through impact, should be on-plane and hence goes inwards and upwards, beyond impact.

A rather different move, re to swinging sharply inwards, but mathematically equivalent, is to stand up through impact such as done by Laura Davis. They can both be analyzed as causing a ‘shortening of effective swing radius’. It does not take all that much to gain a few percent in club head speed.

Curving inwards/upwards is most effective pumping energy into the swing when the club has obtained high speed hence, primarily, just before impact. Perhaps when you will hear now on TV a comment that a golfer is snapping his knee(s) straight through impact, it might take on perhaps a different meaning.

James, the trail arm per se can push in various ways. Perhaps it is better to concentrate on continuing to pivot through and beyond impact. Another useful idea perhaps is to keep the lead upper arm glued to the chest.

You might want to play around for fun with doing part swings with only two thoughts in mind – back swing, trail elbow slides backwards along trail hip and mirror like for through swing - lead elbow slides back along lead hip.

Mandrin,

Thanks for your time and effort to improve everybody's golf swing knowledge

James

 

[starretj]

A rather different move, re to swinging sharply inwards, but mathematically equivalent, is to stand up through impact such as done by Laura Davis. They can both be analyzed as causing a ‘shortening of effective swing radius’. It does not take all that much to gain a few percent in club head speed.

Curving inwards/upwards is most effective pumping energy into the swing when the club has obtained high speed hence, primarily, just before impact. Perhaps when you will hear now on TV a comment that a golfer is snapping his knee(s) straight through impact, it might take on perhaps a different meaning.

Mandrin, would you mind explaining this a little more for us? Thanks for your time.

Jim S.

 

[mandrin]

Mandrin, would you mind explaining this a little more for us? Thanks for your time.

Jim S.

Jim,

I might have posted on this subject on several occasions, but for the moment have a look at this thread where there is a link to ‘Golf swing & playground’ where I analyze the matter of ‘shortening the swing radius’.

 

[mandrin]

yin & yang

Quite a few years ago there was a very naïve enthusiastic scientific current of thinking which entailed that it was only a matter of time that many domestic human activities could be done by robots. Many years later this has not come to fruition. There is a lot we take too much for granted, even done by scientists.

The actual golf swing is also, indeed like all human motions for that matter, a very complex endeavor. I feel that we just don’t realize how complex it is till you start to try to translate it a bit into mathematics. However it is still remarkable that even very simply models can tell us some useful things.

We have seen that when pulling a golf club along a straight line that there are simultaneously two basic motions. A straight line motion of the center of mass and a rotational motion around this center of mass. This is again depicted in Fig1.

Both motions can contribute to clubhead speed but they do it different ways. Initially the linear pulling force creates both a positive linear and angular acceleration. However very soon, due to the changing angle between club and force vector, there is a negative angular acceleration and hence rotational braking.

By folding the linear path roughly into a circle we still have basically the same pattern, Fig2. However we have seen that the ‘linear’ pulling torque is now more efficient over a longer time. One can almost see the folding into a circle as a means to create more ample and efficient motion into less space.

If one takes the linear effort as the yang element and the angular effort as the yin element one can consider an optimum downswing as a balance between the harmonious blending of effort and letting go. To get the max with the least effort one has to let go of the yang to let the yin element play its role.