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Thanks..
Hinge Action, Rate of Closure, and what you SHOULD do with the clubface (p9 pic)
- Thread starter Brian Manzella
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Thanks..
Can't forget any club to ground, mat or lie board contact when hitting a ball off of them.
Dear Brian,
When I responded earlier in this string, (#46), I thought the issue was,’ would differences in ROC angular velocity VARIATIONS significantly affect the results of the shot’??. I responded with some sample statistical calculations.
A bit further in the string I felt that the issue was,’ wouldn't the rotational velocity of the club face add to the overall velocity of the club head AND the ball as it departs 0.0004-0.0005 seconds later’??. This question is also very easy to answer 'scientifically' as the velocity increase to the club face at the center (neglecting ball rotational differences for the moment) is simply the angular velocity of the club face at impact (in radians per second, not degrees per second), times the radius of rotation (the distance from the hosel to the center of the impact). Or, in equation terms, V=rw , where w is defined as the angular velocity (in scientific terms it is known as omega.
In the case of a ROC of 2500 degrees per second (2500/57.3)=43.6 radians per second), and an approximate distance of 3 inches from the hosel to the center of impact results in an 11 foot per second increase in club head speed at this location on the face of the club. BUT the ability, or better yet , the ‘probability’ of the golfer to voluntary time the club face to be square to the desired target line is IMO very low, necessitating an involuntary, predetermined swing ‘habit’ involving both ‘beta’ and ‘gamma’ torques. Unfortunately, to produce these in and out of plane torques, the wrists have to crate motions involving, in the language of the body, ulna deviation, flexion-extension, and forearm supination-pronation. OUCH, COME IN KINESIOLOGISTS PLEASE, MY HEAD HURTS
Fortunately, a careful review of data NOW available and presented by Mike Jacobs’ new 3D AMM system does the work for us, (“Wrist Link Interactions”, pages 8 and 9 of 17). While not not as precise as ENSO, IMO, these data can be analytically corrected and used to help better understand all the club/shaft/club head motions before and after impact with data that are presented approximately every 0.004 seconds. The macro’, or big picture/systematic insights of how the alpha and beta activities are created by the ‘Ulna deviation, Flexion-extension and supination-proation of the Lead and Trail wrists and forearms, provide VIVID pictures of the REAL dynamics affecting the ROC during the downswing (in fact the 'avatar, graphical AND TABULAR data can be presented for the entire swing, ON THE SAME PAGE).
In summary, these TPI data indicate for a driver of PGA capability, an average shaft angular velocity at impact of 1086 degrees per second, with a range of 209(???) to 2521 degrees per second. I talked to Phil Cheetham last year as to the ‘data base’ from which the/TPI derived the parameter ranges, and he said they had extensive data bases for elite/PGA, amateur, and LPGA players all in the in the hundreds of participants, so the numbers noted above are from the PGA data files, and may be different today, as they are updated periodically, but IMO , because of the HUGE data bases, will not change very much.
In conclusion, now with the AMM 3D system, it is possible to view the angular rate changes for a reasonable artifact of the club head, make a few analytical compensations, and see for each swing, and for each golfer the significant variations and changes in position every 0.004 seconds, and even watch the movement of the golfer/avatar in synchrony by the ‘frame by frame’ movement of a cursor, so get ready for a whole new level of science-based insights regarding the details, INSIDE THE GOLF SWING.
Frans@France
New
Brian Manzella
Administrator
The answer is NO, not enough hz...
drewyallop
New
A few questions Art:
1. Shaft angular velocity at impact. Could you provide the median and standard deviation?
2. How does shaft angular velocity at impact translate to rate of closure, i.e. an angular velocity of 209 degrees/second would result in what rate of closure?
3. Assuming we know the rate of closure, how is the additional clubface closure due to toe-down deflection factored into the mix?
Thanks.
Brian Manzella
Administrator
Lot of guess going on.....
That's why they MADE Esno-pro.
Let's all just wait for some real answers...ok?
That's why they MADE Esno-pro.
Let's all just wait for some real answers...ok?
Brian Manzella
Administrator
Ok....
Just talked to Michael Jacobs via Skype and scrolled through a few know PGA Tour players data. (20 min)
Called Chris Como and Jon Hardesty, both familiar with all of these numbers from this and other systems.
Talked to James Leitz owner of a AMM machine for 6 years.
Talked to Art Maffei for 20 minutes....
Stop celebrating out there in TYPO land....
Here are the exact numbers:
Enso-pro ("good player" range) of Clubface Rate of Closure at impact
2400-3000° per sec
TPI AMM Club Handle Axial Velocity
(one set of their data) 631-1881° per sec....(another set) 971-1599° per sec...Els-1750 (at some point in his career)....Furyk 1750° (at some point in their career)
TPI AMM Lead Wrist Pronation-Supination
(one set of their data)
HALFWAY DOWN (Left arm level to ground on the downswing) 323° per sec supination -704° per second supination
IMPACT 1236° per sec supination - 2093° per second supination
You should see the graph of the Lead wrist number....wow! What a ramp up in acceleration!
Brian Manzella: "Art Maffei, is it possible to close the face and then reopen in through impact???"
Art Maffei: "Absolutely no chance."
So...this "209(???) to 2521 degrees per second" from Art's post above was a typo in the data he was given at a test....NO RANGES LIKE THIS EXIST FOR ANYTHING IN THE GOLF SWING IN 3D land.
NOTHING.
If you saw the "bumpy-back keep it back" swing that Art has developed, it is precisely the opposite of a TURN YOUR BODY THROUGH constantly through impact swing.
So....
Call off the parade, I've been dead on correct in this thread and others all week.
Just talked to Michael Jacobs via Skype and scrolled through a few know PGA Tour players data. (20 min)
Called Chris Como and Jon Hardesty, both familiar with all of these numbers from this and other systems.
Talked to James Leitz owner of a AMM machine for 6 years.
Talked to Art Maffei for 20 minutes....
Stop celebrating out there in TYPO land....
Here are the exact numbers:
Enso-pro ("good player" range) of Clubface Rate of Closure at impact
2400-3000° per sec
TPI AMM Club Handle Axial Velocity
(one set of their data) 631-1881° per sec....(another set) 971-1599° per sec...Els-1750 (at some point in his career)....Furyk 1750° (at some point in their career)
TPI AMM Lead Wrist Pronation-Supination
(one set of their data)
HALFWAY DOWN (Left arm level to ground on the downswing) 323° per sec supination -704° per second supination
IMPACT 1236° per sec supination - 2093° per second supination
You should see the graph of the Lead wrist number....wow! What a ramp up in acceleration!
Brian Manzella: "Art Maffei, is it possible to close the face and then reopen in through impact???"
Art Maffei: "Absolutely no chance."
So...this "209(???) to 2521 degrees per second" from Art's post above was a typo in the data he was given at a test....NO RANGES LIKE THIS EXIST FOR ANYTHING IN THE GOLF SWING IN 3D land.
NOTHING.
If you saw the "bumpy-back keep it back" swing that Art has developed, it is precisely the opposite of a TURN YOUR BODY THROUGH constantly through impact swing.
So....
Call off the parade, I've been dead on correct in this thread and others all week.
Brian Manzella
Administrator
Just to repeat....this is STANDARD PRACTICE on the PGA TOUR for what the clubface is doing:
1. At last parallel before impact, the face should be slightly toe down (this one is 2°)
2. About 3 golfballs before impact, the clubhead should be dead on its desired path, and face should be just above dead square to that.
3. The Clubface should rotate closed enough to be on the plane of the clubshaft.
4. The Left Hand should "spiderman" toward the target and the right wrist—full after a throw release—so that #3 will happen.
Anything beyond this will require SERIOUS manipulation, and would be considered "non-standard."2. About 3 golfballs before impact, the clubhead should be dead on its desired path, and face should be just above dead square to that.
3. The Clubface should rotate closed enough to be on the plane of the clubshaft.
4. The Left Hand should "spiderman" toward the target and the right wrist—full after a throw release—so that #3 will happen.
Dear drewyallop,
In an earlier post, I made reference to the AMM Titleist 3DDocument that explained the terms. It was part of the Level 2 Biomechanics Course taught by the TPI Folks. I was lucky enough to find it on the internet, and it is "TPI 3D Biomechanics Report- Interpreting the Data" and I am quite sure it was written by Phil Cheetham AFTER the tests that I conducted at TPI 4-5 years ago.
As a result, the median and range data I put in the post above was from the tests/data I personally witnessed, BUT UNFORTUNATELY FOR ME CONTAINED ERRORS IN THE PGA DATA FOR THIS PARAMETER. I tried to alert the readers to this apparent anomaly by the ???? I placed after the 209 degrees per second, so I apologize and now in answer to your question will replace it with the EXAMPLE DATA from the TPI document rather from the test reports I was directly using for some research on swing style effects on CRUCIAL body dynamic parameters.
So here are the (2008 ish values in the TPI Report---Caution, they may even be changing today )
Club Handle Axial Velocity(at impact) 1606 (for this PGA individual); TPI Calculated Range 971-1599, all in degrees per second. My personal contact and discussions with Phil disclosed that the standard practice of TPI presenting 'ranges of data', was to present the 'mean' and one sigma standard deviation derived from hundreds of players and swings in the PGA etc categories. So, to complete answering your question, I would CALCULATE that the 'mean (a pretty good estimate of the median you requested) would be half way between the noted range, or 1285 degrees per second, a value many will now question based on the recent ENSO results.
This TPI report is CRUCIAL in understanding both the terms AND examples of the data and graphic examples of the 17 page report for each swing. In that report, and in the sensor placements that develop the data, there is NO parameter "shaft angular velocity", but there is a "Club handle Axial Velocity", which IMO can be 'dynamically' adjusted with knowledge of the mounting arrangements to the club shaft.
I have not made that analysis, as I am significantly more interested in how this ROC is developed by the body considering the dynamic interactions of the wrist and forearms during the downswing, especially after the peaks of the kinematic sequence.
So in summary for your first question, shaft angular velocity was shaft AXIAL angular velocity, IMO an artifact of the parameter presented in both the test report I used, and now the update to the TPI document I suggest you get and review for a better understanding of ALL the complicated dynamics involved in the body being able to produce the ROC.
Now, question 2, true club shaft angular velocity (omega) at impact in the TPI Report sited, is noted as 2230 degrees per second for the PGA player selected, and a range of 2108 to 2300 degrees per second. I have not done any research, am unaware of any being done, but I would be very willing to discuss and work with someone interested in studying if there is a significant relationship between the club heads 'swing' velocity and the ROC . And finally, I sure hope you realize that the 209 degrees a second is clearly an anomaly from a 2007 test at TPI.
In your question 3, with club head deflection added as an additional variable in determining a 'Total effective ROC', I like you anxiously await the availability of more ENSO data, as those folks really have 'a dog in that fight'.
Finally, if anyone has taken the time to read all the posts in all the threads discussing ROC, I for one would just like to say, please review actual data that shows the dynamics of the wrists and forearms during the whole golf swing, but especially the downswing, and I think you will conclude as I have, that the ROC alone, is very interesting BUT....
MY PASSIONATE INTEREST IS, What does each golfer have to do to get to repeatable path and club head position within a degree at impact ???? My guess is that it is ALL in the transition and early downswing, and an accurate and repeatable ROC is the RESULT of these earlier events and should not even be attempted any time after the peaks of the kinematic sequences for the pelvis, torso and lead arm which only leave 0.100 seconds until impact.
WHAT DO YOU THINK ???
Frans@France
New
I agree, so I fail to understand why some include the amm3d data in these discussion.....
Brian Manzella
Administrator
Ah....Frans!!!
My club guy!
In your line of work, you know that you would NEVER EVER use AMM data for club fitting.
Why don't you tell the great unwashed.....
Dear Frans@France,
I AM THE ONE STATING THE NEED FOR THE USE OF AMM DATA.
I do not fit clubs, I just for the past 5 years have been seeking what I call golf truth.
I beleive from your comment about 240 hz., you know how the Amm system operates, and realize it produces reliable data from all the sensors without requiring filtering, as the signals produced are very 'clean'. Maybe for what you do, that is too slow.
However, in my world of overall dynamics and stability, especially with regard to the human body and how it operates in producing a golf swing, a reliable data point every 0.004 seconds is very adequate.
What I feel you are missing, or possibly neglecting in your response is to see and believe the dynamics of the shaft, golf club head, and possibly the ball at impact, you need something like the ENSO data Brian has obtained. I AGREE BUT, to see how the body is producing the forces and torques to establish the motion and paths of the golf club to get to impact during at least the full downswing requires the time-phased (every 0.004 seconds) parameters that the AMM system provides.
If you have any other test systems that can provide at least the shoulder complexes, arms, wrists and club data at these or higher frequencies PLEASE NOTE THEM in your response to my points above please.
Respectfully,
art
Frans@France
New
mgranato
New
This is the genesis of all the nonsense. The One release that causes the club face to react differently upon impact, The One that TM or FS can not appreciate, and The One that cannot be captured on 3D.
The Matrix of releases.
Frans@France
New
Lost with this part of the reply. Do you mean which system I own or which system I know is faster dan 240hz and can capture body part movements at higher rates? Any marker system which includes high speed camera's! (Like the enso)
That discussion has been done on this forum before including the error produced by these marker systems in relation to the real bone position because of skin movement artefacts. Having a
then has no real meaning. Let me quote a conclusion "body segment rotations obtained using different definitions will produce different results and cannot be compared easily"art said:
birly-shirly
New
Point taken. But in that case (i.e. that we can rule out the possibility of superhumanly quick manipulations and counter-manipulations), shouldn't 240Hz be fast enough to capture decent data about what IS happening in terms of axial grip rotation?
mgranato
New
I would think so, as long as it is understood what the limitations are and what that data is and isn't saying about the rest of the equation.
Dear mgranato,
I am offended by your reply referring to me as "the genesis of all the nonsense ".
I have always given my posts the 'value added' test before hitting the send button. Also, I have tried in EVERY post, to communicate and share a summary, or a simplification of some 'golf swing related' engineering or science that I learned in reviewing now over 1000 technical research papers.
I have taken the time to use Brian's site and review some of your past posts, and with the exception of a few spelling 'anomalies', you seem to be intelligent enough to have a an opinion about ROC, and some of the related dynamics of the golf swing.
So here is my challenge to you ; simply provide me (and all the others tat have a sincere interest in learning) WHY you think my science is 'nonsense' and be specific with special regard to the topics in this thread that you think I have been nonsensical.
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