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Post by imperfectgolfer on Nov 9, 2020 22:56:52 GMT -5
DG,
You wrote-: "If the right hand 'In Plane Positive Hand Couple' moves to a more horizontal plane from P5.5-P6 to shallow the swing plane, then there is less likelihood of an early PA#2 release (ie. the net 'In Plane Positive Hand Couple' will be less).
Therefore a golfer who shallows the swing plane will have less net positive 'In Plane' hand couple when the MOF takes over (ie. the red and green lines in Dr Kwon's graph would cross closer to the zero axis)."
I cannot understand why you believe those assertions.
Jeff.
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Post by dubiousgolfer on Nov 10, 2020 12:00:09 GMT -5
The problem with my assertions is that is doesn't tally with Dr Kwon's graphs .If my postulation above were true then all those Dr Kwon graphs would infer that there wasn't much clubshaft shallowing happening (because ALL the graphs show a positive hand couple when the red/green lines cross over). However , the idea of a centripetal pull (probably a reactive one) via the right hand is suggested in Choi's graph G below . So it seems that the dynamic weight of the club is shared by both the left and right arms (but favouring the right arm). But then again , this is contradicted by Koike's graph 'b' below where there is very little force up the shaft (even negative) by the right hand. Almost as if the left arm is pulling up the shaft while the right hand is dragging back. I suspect this is proof of differing kinetics happening in the golf swing specific to the players different techniques. Back to the drawing board :-( DG PS. Look at the large variations in that Choi 'C' and 'G' graphs (ie. the shaded regions). Suggests that there isn't any generic pattern of forces being applied by the left and right hands up and down the shaft. ADDENDUM1 I now think that a golfer who uses a significant shallowing move is applying 'extra right hand couple' but not completely 'In Plane' but also some 'out of plane' hand couple to shallow the club. By doing this he is adding an extra component to his previous existing instantaneous 'In Plane' positive hand couple . This could cause an early release of PA#2 before the MOF takes over. Therefore: 1. Golfers who shallow the club more will have more positive 'in plane hand couple' at the point that the red/green graph lines cross over in Dr Kwon's graphs. 2. Golfers who don't shallow the club as much will have less positive 'in plane hand couple' when those red/green graph lines cross. ADDENDUM2 From what I've read on Dave Tutelman's site, the 'assist release' hand couple timed precisely at 70 msecs before impact could be used to supplement any falling off of 'centrifugal force' (ie. which is basically a pragmatic way of saying a decrease in clubhead speed) . Therefore as the golfer tries to shallow the clubhead from a steeper to shallower plane, he/she is aware of this 'falling off' of the 'In Plane ' hand couple and is applying some extra torque to keep it at a certain level to prevent any decrease in clubhead speed as the MOF becomes positive and takes over clubhead acceleration.
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Post by imperfectgolfer on Nov 10, 2020 14:20:10 GMT -5
I am no longer capable of understanding what you are trying to communicate in your posts.
Jeff.
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Post by dubiousgolfer on May 30, 2022 11:16:57 GMT -5
I am resurrecting this issue again because I am still questioning Dr Kwon's assertion that the 'hands/clubshaft/clubhead' are all moving on some well-defined functional swing plane from MD-ZC (ie. P6-P7.3 approx). Further I think that giving this perception to a golfer may cause him/her to shank the ball. It might be an approximate functional swing plane because Dr Kwon uses words like "the mid-hand-point is pretty much on the swing plane" but I think golf scientists need to be more precise when describing biomechanics in the impact zone (as defined below). Impact Zone Look at this video of a double pendulum swinging on a vertical functional swing plane. One can imagine that if the proximal arm had to rotate (akin to the lead forearm of a real golfer) to square the clubface while keeping the clubface sweet spot on that plane, the proximal arm and hinge joint would have to move under that plane (into the screen). This would apply mainly to a golfer with a weak-neutral grip who retained some PA2 angle by P7. Therefore, it seems incorrect that the hands and clubhead are moving on the same functional swing plane and, if that is the case, the club shaft is not constantly on some well defined functional swing plane. Note in above video that the clubface was always square to the path which would apply to a golfer with a very strong grip. DG
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Post by dubiousgolfer on Jun 1, 2022 10:52:45 GMT -5
To check whether my logic in the above post was correct I asked Kevin Ryan and he said the following:
My question: Kevin - there is a lot of talk about the whole club shaft being swung on a near perfect functional swing plane from P6- P7.5 approx. Dr Kwon has mentioned this on his you-tube channel videos. But if there is an angle between the lead arm and club shaft from P6-P7 , isn't it impossible for a the whole shaft (including the hands/grip) to traverse on a single functional plane? Surely the lead hand would have to move inside as the lead forearm/arm rotates to square the clubface (while the clubface sweet spot remains on this functional plane)?
Kevin Ryan reply:
"You are correct on multiple issues: (a) In the functional swing plane, the whole shaft (including the Hands) will traverse a plane. (b) the lead arm must move inside (and therefore off the functional swing plane) as the forearm rotates to square the clubface.
To understand this take a club in your lead arm and bend down against a table top with your lead underarm on the tabletop. Do this slowly, I don't want accidents. Now try to execute a double pendulum. You can't because your lead wrist locks. You could rotate your forearm but then the clubshaft would leave the functional swing plane. Now to understand the RYKE effect, as the clubshaft reaches club horizontal, lift your shoulder off the table top. Now you can rotate your forearm and the ryke angle will form and the shaft will stay on the functional swing plane. This is equivalent to moving the lead arm inside. In a full swing this inside move starts at about club vertical."
Coincidentally, he is using virtually the same argument that I posted above when using that video of a double-pendulum on a vertical 'functional swing plane'.
DG
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Post by imperfectgolfer on Jun 1, 2022 21:56:49 GMT -5
DG - I cannot understand why you believe that the lead hand must move under the FSP for the clubshaft to remain on the FSP between P6 => P7.
Take a large piece of cardboard to represent the FSP at a ~ 50 degree angle and hold your lead hand and clubshaft on the cardboard at a simulated P6 position. Then let the clubshaft move down the cardboard swingplane to P7 while allowing the lead wrist to uncock in a simulated PA#2 release action. As one starts to release PA#3 at time point when PA#2 is already significantly released one can still keep the lead hand on the FSP if the lead hand is elevated during the lead forearm supinatory roll motion of the lead forearm - fully understanding the fact that the roll motion is happening when the lead wrist is becoming significantly ulnar-deviated and the club is significantly released.
I cannot mentally picture the scenario that Kevin is describing.
Jeff.
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Post by dubiousgolfer on Jun 2, 2022 8:43:45 GMT -5
DG - I cannot understand why you believe that the lead hand must move under the FSP for the clubshaft to remain on the FSP between P6 => P7. Take a large piece of cardboard to represent the FSP at a ~ 50 degree angle and hold your lead hand and clubshaft on the cardboard at a simulated P6 position. Then let the clubshaft move down the cardboard swingplane to P7 while allowing the lead wrist to uncock in a simulated PA#2 release action. As one starts to release PA#3 at time point when PA#2 is already significantly released one can still keep the lead hand on the FSP if the lead hand is elevated during the lead forearm supinatory roll motion of the lead forearm - fully understanding the fact that the roll motion is happening when the lead wrist is becoming significantly ulnar-deviated and the club is significantly released. I cannot mentally picture the scenario that Kevin is describing. Jeff. Dr Mann If there is a PA2 angle and you are rotating your lead arm/forearm to square the clubface , you won't be able to keep the lead hand perfectly on some well-defined functional swing plane (ie . inclined at some set angle to the horizontal ground from P6 to P7). The hands/shaft/clubface will all be on the same 'instantaneous plane' but not constantly on a well-defined plane FSP. I've tried that table-top exercise that Kevin Ryan described and I cannot square the clubface (with a weak/neutral grip and an intact AFLW/LFFW) and also keep the lead hand/shaft on the table top without lifting my lead shoulder socket. The fact that Dr Kwon says that the hands are 'pretty much' on the FSP doesn't sound very scientific to me or 'well-defined'. There is no difference between the table-top exercise and a large piece of cardboard to represent the FSP. DG
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Post by imperfectgolfer on Jun 2, 2022 14:34:02 GMT -5
DG,
You wrote-: "If there is a PA2 angle and you are rotating your lead arm/forearm to square the clubface , you won't be able to keep the lead hand perfectly on some well-defined functional swing plane (ie . inclined at some set angle to the horizontal ground from P6 to P7)."
Why do you think it is not possible?
Watch the first 40 seconds of this video.
Jeff.
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Post by dubiousgolfer on Jun 2, 2022 20:13:11 GMT -5
DG, You wrote-: " If there is a PA2 angle and you are rotating your lead arm/forearm to square the clubface , you won't be able to keep the lead hand perfectly on some well-defined functional swing plane (ie . inclined at some set angle to the horizontal ground from P6 to P7)." Why do you think it is not possible? Watch the first 40 seconds of this video. Jeff. Dr Mann If I'm not mistaken, and if you look closely, it seems that your plane board is changing angle quite a bit (riding up and down your knees/thighs) as you move the club from P5.5 to P7. It seems to move from a steeper to flatter plane, which is why you can keep the club shaft more or less on the plane board while rotating your left forearm. I also cannot clearly see the whole shaft touching that plane board as you released PA#3. DG
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Post by imperfectgolfer on Jun 2, 2022 20:46:56 GMT -5
DG, You wrote-: " If there is a PA2 angle and you are rotating your lead arm/forearm to square the clubface , you won't be able to keep the lead hand perfectly on some well-defined functional swing plane (ie . inclined at some set angle to the horizontal ground from P6 to P7)." Why do you think it is not possible? Watch the first 40 seconds of this video. Jeff. Dr Mann If I'm not mistaken, and if you look closely, it seems that your plane board is changing angle quite a bit (riding up and down your knees/thighs) as you move the club from P5.5 to P7. It seems to move from a steeper to flatter plane, which is why you can keep the club shaft more or less on the plane board while rotating your left forearm. I also cannot clearly see the whole shaft touching that plane board as you released PA#3. DG I simply rested the plane board against my thighs so it did move around as my body moved. It is easy to verify the principle by having a fixed planeboard and swinging a golf club along the surface of that plane board between P6 => P8. Jeff.
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Post by dubiousgolfer on Jun 2, 2022 21:29:16 GMT -5
Dr Mann Here is a graph that I saw in one of SMK's research article. The black dotted line shows the measurement of the downswing plane of the club shaft for a driver swing as measured by Coleman and Anderson (2007). Unfortunately, I don't have a copy of that original research article "An examination of the planar nature of golf club motion in the swings of experienced players" and cannot be certain if the graph was an average over a large sample of golfer driver swings or a single golfer. If the golfer's driver downswing is about 0.25 secs , P6-P7 would be about 0.07secs from impact , therefore that black-dotted graph should plateau off from about 80% of the downswing point if it was traversing on some well defined FSP. As you can see the club shaft plane gets progressively flatter approaching impact. I don't have the article or data that Dr Kwon used that resulted in some well-defined FSP from P6~P7.3 or whether he noted : 1.The lead hand grip strength of the golfers used 2.If they performed a swing with an intact 'AFLW/LFFW' with any significant PA2 angle when PA#3 was released. The video above is flawed because he has a white ball preventing the club shaft from lying flat on the plane. The club shaft could be angulated even more in that gap where there is no plane board while different parts of the curved surface of the ball remain in contact. DG
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Post by imperfectgolfer on Jun 2, 2022 21:50:09 GMT -5
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Post by dubiousgolfer on Jun 3, 2022 7:22:41 GMT -5
Dr Mann Look at the 1:55 point (images below) where she has moved from P6-P7 and squared her clubface by the slow motion release of PA#3 . Does the shaft look flat on the plane board to you? If you placed a ball touching the plane board at P7, the hosel of the club is more likely come into play? DG
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Post by imperfectgolfer on Jun 3, 2022 16:15:59 GMT -5
Dr Mann Look at the 1:55 point (images below) where she has moved from P6-P7 and squared her clubface by the slow motion release of PA#3 . Does the shaft look flat on the plane board to you? If you placed a ball touching the plane board at P7, the hosel of the club is more likely come into play? DG It is flat enough against the plane board for me to understand the principle of the clubshaft remaining against the surface of the planeboard between P6 => P7. It is also adequate enough for me to note that her hands can be on the same FSP as the entire clubshaft between P6 => P7.
You stated-: "If you placed a ball touching the plane board at P7, the hosel of the club is more likely come into play?"
That's exactly what should happen if the clubshaft is lying flat against the plane board, then the hosel should be positioned at the point where the planeboard meets the ground. If a golf ball was placed at the exact point where the planeboard reaches the ground, then that's where the hosel should be situated. From the perspective of TGM ideology, a line is drawn from the butt end of the club to the sweetspot of the clubface as representing the idea of being "on-plane". However, I prefer that the line be drawn along the longitudinal axis of the clubshaft (or a Smartstick laser rod) when trying to conceptualise the "idea" of a FSP along which the clubshaft travels between P6 => P7.
Jeff.
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Post by dubiousgolfer on Feb 16, 2024 11:15:56 GMT -5
Revisiting this thread , I have found the following video which shows that the club shaft is not swinging within a functional swing plane if there is a PA3 angle at impact. However, the clubhead's hosel can be touching that functional plane (but not the whole shaft).
The previous post shows the swing plane board being used by Martin Hall where the female is trying to keep the whole shaft swinging within the board plane, while also trying to square the clubface. In my opinion that is only possible if she loses any PA3 angle first while the whole shaft is touching the board, and then squares the clubface just before impact.
In the video below, one can clearly see that the lead arm swing plane must steepen if the clubface is squared by lead forearm rotation with an intact GFLW/LFFW and a PA3 angle at P7. Therefore the whole of the club shaft cannot be swinging within a functional swing plane (note how the 'shaft' has to move beneath the 'explanar type gadget' plane from P6-P7) while the 'head' is still touching the plane rim.
Further , look at Martin Hall's short video above where he is ensuring the whole of the shaft is swinging on the same functional plane from P6-P7 and note that he is keeping the clubface square to the path from P6-P7 without any forearm rotation, which is obviously not reflective of a real golfers swing. In my opinion , practicing swinging on a plane board trying to keep the whole shaft within a functional swing plane is flawed if you are a golfer who prefers a PA3 angle at P7.
DG
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