HAND Path... the key to effortLESS club head speed.

Well the results are in and they are definitive... Controlling one's hand path is the key to attaining more clubhead speed with less effort. I feel vindicated having argued this very point with another ad infinitum on a lesser forum over the past couple of years.

In the posts below we discussed the research efforts of Professor Steve Nesbit (of Lafayette University) and professor Moria's earlier findings. Using today's most sophisticated modelling softwae and methods, Nesbit has developed, using accurate 3D measurements, a validated model of the golf swing... the first of its kind.

By putting measured kinematic (path and velocity) data into his model he can accurately determine the forces, torques consequently total work and power. In his latest effort employing said model, Professor Nesbit and his student researcher (Mr McGinnis) set out to determine the role hand path plays in golf swing efficacy. The results (although not unexpected by some of us) are astonishing and highly significant. Breifely summaraized:

1) Double pendulum math models of the golf swing are garbage ... nobody swings a golf club that way and they overlook the key factor...(hand path). The hand path (ie hub) radius is constantly changing as is the center of curvature.

2) Hand Path plays a key role in determining maximum club-head speed given an individual golfer's constraints: maximum torque, maximum force generated. Tiny women golfs can achieve great results because they use their hands better.

3) All golfers have similar maximum hand speeds (slightly more than 11 m/s in this study) and only one of the subjects tested hands slowed down prior to impact (his by 11% and he's a high handicapper). Kinetic chain snapping is garbage.

4) All golfers likely have big room for improvements...

side note* There is NO centrifugal force in the model because (aside from gravity) the only forces involved are those attributable to the hands. See free body diagram: http://www.jssm.org/vol8/n2/11/F1.htm

I'll focus the rest of this post on item 4. Nesbit and McGinnis discovered (at least this it the first time I've ever read about it described as such) 3 distict phases of the golf swing. All test subjects exhibited them. http://www.jssm.org/vol8/n2/11/F5.htm Transitions between phases are defined by local minima in the hand path radius which also correspond with changes in the direction of the center of curvature (of hand path).

They singled out their scratch golfer subject for optimization. They took is individual constraints (max and min hand path radii, max force(s) (i.e. normal and tangential) max torque (hitter effort in TGM terms) etc. and let the computer go to work optimizing his hand path. After 80 million iterations the computer arrived at a hand path for the scratch golf that would (again given his personal constraints) allow him to achieve 4% more club head speed with considerably less (-16%) effort (less power in the true mechanical senses of the words)
http://www.jssm.org/vol8/n2/11/T7.htm. Phases 2 and 3 of the optimized path resemble a logarithmic spiral. See for yourself: http://www.jssm.org/vol8/n2/11/F7.htm

Here is a link to the paper:
http://www.jssm.org/vol8/n2/11/v8n2-11text.php#7

********* from the paper ************
KEY POINTS
-The golf swing hub path was found to have a complex geometry with significantly changing radii, and a constantly moving center-of-curvature during the downswing.
-The hub path differed considerably among subjects, however a three phase radius-based pattern was revealed that aligned with distinct stages of the downswing.
-The shape and purpose of the hub path geometry appears to result from a complex combination of achieving equilibrium between the golfer and the club, and a purposeful configuring of the path to control the outward movement of the club while minimizing the kinetic loading on the golfer yet transferring the maximum kinetic quantities to the club.

Double pendulum math models of the golf swing are garbage ... nobody swings a golf club that way and they overlook the key factor...(hand path). The hand path (ie hub) radius is constantly changing as is the center of curvature.

The Pot Calling the Kettle Black.

Tiny women golfs can achieve great results because they use their hands better.

No_Mind_Golfer, you've lost your mind!



A grant from the National Science Foundation made this study possible. Are you kidding me??? Tax Dollars at work. I'm surprised that this isn't part of the Stimulus Package (oh, I mean the save your 'government job' package) DRIBBLE. Stupid study based on other stupid studies. Waste of time junk science. Spend time reading this crap to find out you've read a lot of crap.

Did these idiots ever think of measuring Clubhead speed and Hand Path without using a ball? Then compare results?

This is why I don't listen to scientists. I've never met a Scientist that I didn't think was an idiot. Economists too. Elected Officials too.

Law of the Flail. Endless Belt Effect. Accumulators. Straight Line Delivery Path. Snap Release.

What this study teaches is that after spending time and money, nothing is learned that wasn't already known, and the summary information won't reduce your scores by a single stroke. Geeks.

Amen, Daryl

NMG,

Thanks for the link. Very interesting indeed!

I've read through the whole paper. I didn't digest all of it; it is a hard read. But I got a few things out of it.

From a user perspective, the optimized hub path is very interesting.

Question 1: How to get the hands closer to origo at 9 o'clock? Potential answer: By aggressive weight shift. And more shoulder rotation and delay the extencior action.

Question 2: How to achieve a shorter swing radius / more rotation through impact? (and more thrust?) Potential answer: A stance and impact where the shoulder has rotated further than befare, later release.

We need more of this stuff. The fact that a lot of youngsters appear and seemingly hit the ball a mile with very slim bodies indicates that the current SOTA has headroom with regards to the most efficiant stroke possible.

The hand path, the hands plane - pp#1 - is very important to understand.

The radius is relative to the 'center' - a perspective which is lacking in most measurements of the swing and not a body part from which to visually measure, but that of the forces involved.

Originally Posted by BerntR NMG,

Thanks for the link. Very interesting indeed!

You're welcome but its Prof Nesbit that deserves all the kudos/thanks. I already emailed him a letter of encourgement knowing that his work would likey be "beyond comprehenssion" of the masses (as exhibited by a few of the posts above).

Originally Posted by BerntR NMG,
I've read through the whole paper. I didn't digest all of it; it is a hard read. But I got a few things out of it.

From a user perspective, the optimized hub path is very interesting.

Question 1: How to get the hands closer to origo at 9 o'clock? Potential answer: By aggressive weight shift. And more shoulder rotation and delay the extencior action.

Question 2: How to achieve a shorter swing radius / more rotation through impact? (and more thrust?) Potential answer: A stance and impact where the shoulder has rotated further than befare, later release.

We need more of this stuff. The fact that a lot of youngsters appear and seemingly hit the ball a mile with very slim bodies indicates that the current SOTA has headroom with regards to the most efficiant stroke possible.

I agree completely ... we need more of this stuff... basic research on things that benefit the masses as apposed to the few. As a US citizen and tax-payer I am happy to see a pittance of my tax monies go towards these sorts of things (which is in contrast to billions for banksters and the military industrial congressional complex).

“Leadership is unlocking people's potential to become better.”
Bill Bradley

In this life there are leaders and there are followers. There will be the leaders among us that recognize the potential of what is being said here. Think about ... What Nesbit's research is saying is that a scratch golfer can go from hitting his drives 280 yards to 292 and use LESS energy in process (16% less energy!). It also assumes that linear force is his limiting factor. What if linear force is not this scratch golfer's limiting factor? What if the amount of linear force measured during his initial testing could be even greater? That would imply that it is quite possible that MORE... potentially much more than 4% CHS improvement can be had.

Like the Nasa space program... basic research spawns spin-offs (for those who can recognize and seize the opportunity)

There will be leaders that recognize the possibilities presented by Nesbit's research. Those leaders, like you have already done, will begin to imagine ways to improve the golf swings of both themselves and their students utilizing this newfound knowledge. They will be the "TOP 100 " teachers and their students the pga pro's of the future... count on it!

I was down at the range the other day and this young girl and her dad came and set up in the stall next to me. She couldn't have been much more than 12 or 13 but when I heard a woosh out of my left ear as her dad was off getting balls from the machine I began to take notice. Her dad having returned split the bucket between the two of then and she began knocking the heck out of them! I mean here's a young girl probably 100 lbs max (but flexible as a noodle) and she driving 200 yards easily! I though about Nesbit's findings; I wish I had a way to visualize her hand path and confirm my suspicions.

What was really funny was when this girl starts telling her Dad why he's slicing! "Lemme see your grip dad..." "here do it more like this"... " Hey you're right , he says".... "I'm always right Dad.... I've had so many lessons (she says with a smile)" Future LPGAer? I wonder.

NMG, how does your interpretion of Nesbit's work fit in with Homer Kelley's ideas of "straight line delivery path" and "circular delivery path" - Homer was describing curved paths of varying radii along time ago...

I'm not NMG, but I'll give it a try anyway; My try

First of all, I think the acronym G.O.L.F is telling of Homer's insights in this regard: Geometrically Oriented Linear Force. So obvious he must have understood that linear force was the driving force (as long as it is geometrically correct oriented).

Then I think there are quite a few of the consepts in TGM that fits in - like the different delivery paths and the endless belt effect.

In spite of all the experiments Homer did, I regard his work as theoretical, mechanical and schematic in a clarifying way, and perhaps less empirical and biomechanical oriented compared to this paper. I never quite believed that the straight line delivery path was possible, and here we see an empirical orientet paper that produces something that partly supports the guts of this path, partly presents something that seems more likely to happen in a real stroke.

I am a strong believer in a triangulation approach when it comes to learn & discover. I think reading Nesbit's paper in a TGM frame of reference is much more telling than just reading it on it's own merits. The two shed light on each other.

Nesbit's optimized scratch golfer path is perhaps the optimal path to the subject scratch golfer, but perhaps not the optimal path for any uncompensated stroke. I think this fits well with the guts of TGM.

I am rather convinced that TGM - as any ground breaking work - isn't a complete body of knowledge - and will perhaps never be. And I think empirical, biomechanically and detailed mechanical studies may bring new insights to the table. Some of it will give us better understanding of what Homer really knew and some of it will provide important nuances to the schematics that he provided - and some of it may even be a corrective to some of the current TGM SOTA.

I read somewhere that Einstein deliberately chose to use the terms mass, time and distance in his theory of relativity because "... it would be easier for people to understand the theory then ...". Such a line of reasoning more than indicates that Einstein had an understanding that went much deeper than he was able to put down on paper. I suspect that HK had a similar deep understanding of the golf stroke and that the words in TGM doesn't tell the whole story. And I think we will need his framework forever to put in perspective whatever modern empiric research will reveal.

Originally Posted by golfbulldog NMG, how does your interpretion of Nesbit's work fit in with Homer Kelley's ideas of "straight line delivery path" and "circular delivery path" - Homer was describing curved paths of varying radii along time ago...

Nesbit concludes that a non circular hand path is superior!!!

Originally Posted by golfbulldog NMG, how does your interpretion of Nesbit's work fit in with Homer Kelley's ideas of "straight line delivery path" and "circular delivery path" - Homer was describing curved paths of varying radii along time ago...

golfbulldog, I'll attempt an answer with one caveat: I'm no Homer Kelley TGM expert. My understanding of "straight line delivery path" is taking ones hands from the top straight towards the ball. My understanding of "circular delivery path" is ones hand following a circular path from the top.

Neither of those scenarios happens... ever... The only golfer that has a circular delivery path is a machine: either pingman or iron byron. Its clear from Nebit et al that the hand path of all (real) golfers is curvilinear and is unique to each person. Furthermore all hand paths have three distinct phases defined by max/min of the hand path radii and a change in the trending direction of the center of curvature. Those parameters define a golfer's unique signature or swing "fingerprint" if you will.

In the optimization phase of the subject study, Nesbit (and McGinnis) did consider a circular delivery path and (given the scratch golfer's individual constraints) it was indeed better than the scratch golfer's original (much more elliptical) hand path (that is assuming a human golfer is even physically capable of putting his/her hands on a circular delivery path) but.... (as mentioned above) Not as good as an optimized curvillinear path.

Homer Kelley would have been lucky to have had a Commadore 64 computer when he's was researching the golf stroke. Its almost unfathomable how much more commuting power Nesbit (and all of today's researchers) have access to (including software tools and speed). Perhaps one needs a technical to understand this tremendous advantage and therefore no fair comparison can be made.

That said ALL research builds apon what came before... ALL technical papers begin with a review of the previous literature. We scientists pay hommage to people like Homer who paved the way for what was to come.

One of my favorite movies is Kubrick's 2001 a Space Odyssey... Its an allegory for man's "Great Work" in the alchemical sense based on Clarke's Childhoods End. One could liken TGM as the result of the first appearance of the black monolith... Thanks to the efforts of people like Prof. Nesbit the black monolith has made its its second appearance and Golfdom is the beneficiary. The wheels of progress grind slow ... but oh so smooth!

I encourage those readers that find value in Nesbit's reseach like I do to drop him a linet. He says if we keep reading he'll keep writing. (What a deal!) Anyway I've asked him to test some pros so we can see how their dynamics compare to the amateurs.

[quote=Daryl;66066]Tax Dollars at work. Stimulus Package



Maybe I will put in a grant for 2 months at the swamp!!

We will call it the "profession location venue change project"

[quote=needham;66086]

Originally Posted by Daryl Tax Dollars at work. Stimulus Package



Maybe I will put in a grant for 2 months at the swamp!!

We will call it the "profession location venue change project"

JOB TRAINING or CAREER STUDIES

Originally Posted by Daryl This is why I don't listen to scientists. I've never met a Scientist that I didn't think was an idiot.

Daryl,

What color is the sky in your world?

Originally Posted by drewitgolf Daryl,

What color is the sky in your world?

NESBIT received a Grant from the National Science Foundation. Nesbit used some of the money to do research and publish his findings, that the Golf Clubhead and Hands do not travel in a perfect circle. Do you know how much money he received?

Furthermore, his Model is a 2 Barrel Switter. I'd hate to see the Price Tag for a 3 Barrel Swinger.

National Science Foundation Awards $243,526 Grant for Structural Engineering Research

http://www.lafayette.edu/news.php/view/4493

Gotta wonder what the USGA paid him.

Originally Posted by Daryl Law of the Flail. Endless Belt Effect. Accumulators. Straight Line Delivery Path. Snap Release.

What this study teaches is that after spending time and money, nothing is learned that wasn't already known, and the summary information won't reduce your scores by a single stroke. Geeks.

D . . . Question for you . . . In another thread on Right Forearms you have sited Sergio for "throwaway" . . . . now we can certainly debate his Power Package alignments at Impact . . . but I will agree with you that the integrity of his wedges are compromised certainly after the ball is gone and maybe before. BUT . . . . . most of the pros believe that he is the best ball strike on tour . . . .

So what is he doing correctly that overrides his Flying Wedge alignments?

I would put my Flying Wedge alignments up against most on this forum and not be embarrassed . . . BUT I can certainly hit some shots that would embarrass me. So . . . the wedge alignments are certainly HUGE . . . but they are not the only deal. The ball doesn't know if you bent your left wrist if the club is still satisfying the On Plane and 3 function alignments. Not saying you should do that BUT . . . . you believe the best ball striker in the world to be a throwaway artist . . . . maybe we should look at his hand path and the alignments in his pivot and the dynamic loading and unloading of his accumulators and see what we can learn. Just because his compromised wedges offend your TGM sensibilities doesn't mean that there's not something there of GREAT IMPORTANCE to get in the old game.

Originally Posted by 12 piece bucket D . . . Question for you . . . In another thread on Right Forearms you have sited Sergio for "throwaway" . . . . now we can certainly debate his Power Package alignments at Impact . . . but I will agree with you that the integrity of his wedges are compromised certainly after the ball is gone and maybe before. BUT . . . . . most of the pros believe that he is the best ball strike on tour . . . .

So what is he doing correctly that overrides his Flying Wedge alignments?

I would put my Flying Wedge alignments up against most on this forum and not be embarrassed . . . BUT I can certainly hit some shots that would embarrass me. So . . . the wedge alignments are certainly HUGE . . . but they are not the only deal. The ball doesn't know if you bent your left wrist if the club is still satisfying the On Plane and 3 function alignments. Not saying you should do that BUT . . . . you believe the best ball striker in the world to be a throwaway artist . . . . maybe we should look at his hand path and the alignments in his pivot and the dynamic loading and unloading of his accumulators and see what we can learn. Just because his compromised wedges offend your TGM sensibilities doesn't mean that there's not something there of GREAT IMPORTANCE to get in the old game.

Sergio is one of the greatest Golfers to ever play.

Sergio has a tiny little Throwaway. So do most of the Pros at least off the Tee. It's hardly anything. But anytime the Clubhead gains on the Hands before or During impact, by Flattening the Right Wrist, no matter How Slight, it's termed Throwaway. Hinging is the Opposite of Throwaway.

I believe that there's a Lot more to Golf than Swinging a Club Perfectly. It's still and always will be part "Art". Hinging may be easier for a Hitter. I know that its much more difficult for a Swinger to learn.

When it come to Scoring, I don't care how it gets done. When I'm thinking TGM Theory I'm a purist.

Originally Posted by Daryl Sergio is one of the greatest Golfers to ever play.

Sergio has a tiny little Throwaway. So do most of the Pros at least off the Tee. It's hardly anything. But anytime the Clubhead gains on the Hands before or During impact, by Flattening the Right Wrist, no matter How Slight, it's termed Throwaway. Hinging is the Opposite of Throwaway.

I believe that there's a Lot more to Golf than Swinging a Club Perfectly. It's still and always will be part "Art". Hinging may be easier for a Hitter. I know that its much more difficult for a Swinger to learn.

When it come to Scoring, I don't care how it gets done. When I'm thinking TGM Theory I'm a purist.

Witcha . . . BUT . . . . what defines a TGM purist? To me the beauty of Mr. Kelley's work is the catalog . . . . putting the components together . . . . Just think about the different stuff just with something as isolated as Knee Actions and all the different implications that result in the other components (even how it effects the hand path stuff in this thread) Does one Knee Action make it easier to have a particular Hand Path? . . . . pretty awesome that a dude could even catalog that WITHOUT video.

***First a correction***

In my last post I said that during the optimization part of the study Nesbit/McGinnis studied a "circular delivery path" and found it to be better than the scratch golfer's original hand path. That's not true ... what they found was that to get the same clubhead speed using a "circular delivery path" would require 10% MORE power (a lot more torque). (See table 7 http://www.jssm.org/vol8/n2/11/T7.htm ) . Looks like "circular delivery" is out.

**********************

Now as to your question bucket...

It takes three points to define a plane (any plane). So if we were to take the coordinates of the hands at the top of the swing, in the middle of the downswing and at impact we can define a plane... lets call it the hand (hub) plane. That's what we're looking at in that graphic I overlayed the spiral on. Its not a front view, side view etc. ... is a view perpendicular to that hand plane.
X and Y are just cartesian coordinates on a plane. The curves are the path the hands trace on that plane. BTW Nesbit does not tell us how much the hands actually deviate from said plane. That would be nice to know.

I hear the question: How do you teach it?

Our problem statement is: how do we to maximize CHS given fixed kinetic (muscle power) limitations?

To solve any problem we must get to root cause; and a jouney of 1000 miles begins with the first step.. That what Nesbit and McGinnis have done here... They have shown definitively that hand path is THE KEY FACTOR involved in maximizing the kinetic transfer (from body to club) i.e. root cause. Furthermore the computer has told us that the optimal hand path for the blended second and third phases of the downswing should resemble a spiral (at least for this scratch golfer). Now biomechanics must tell us how that hand path goal is best achieved... what muscle groups need developing to improve the kinetic limitations and what areas of flexibility are needed... sequencing etc.

Today the latest rage is radar reports of what is happening at impact. That's all well and good but I can envision a day in the not too distant future when Instruction will begin by setting up camera(s) (or sensors of some type), plugging in computer having a validated biomechanics model of student (not unlike Nesbit's). Swing is captured and within seconds optimized improvement suggested (including animations showing how to move differently in order to achieve).

I can see it now... in the not too distant future Kostis will be expounding on a golfer's screwed up hand path seconds after the mis-hit. Gone are the days when golf was a pastime of the pipe-smoking leisure class dressed in stiff suits and bowtie swinging hickory sticks. We're on the the verge of maximizing human potential now.

Originally Posted by 12 piece bucket Witcha . . . BUT . . . . what defines a TGM purist?

I think that TGM is a Method and that it's Itemized in 12-1-0 and 12-2-0. Specialty strokes use a different variations or are zeroed out.

NMG - another cool post. You come up with some mad scientist stuff. Thanks.