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
********* 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.
Quote:
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.
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.
__________________
"Support the On Plane Swinging Force in Balance"
"we have no friends, we have no enemies, we have only teachers"
Simplicity buffs, see 5-0, 1-L, 2-0 A and B 10-2-B, 4-D, 6B-1D, 6-B-3-0-1, 6-C-1, 6-E-2
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).
Quote:
�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.
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!!!
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.
Hybrid Mode
