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Post by imperfectgolfer on Sept 12, 2013 21:28:56 GMT -5
Jeffy,
It could well be that MD didn't express himself correctly. When he answered 10, I presumed that he had 10 markers along the length of the spine. When he stated that he only looked at the differential difference between the upper and lower torso motion, then I presumed that he wasn't using the information from all the 10 markers, but only the differences between the upper and lower markers. Either way, it doesn't matter to me because I don't believe in the value of 3-D systems. Even if he had 10 markers along the length of the spine, I doubt that I would acquire a better mental picture of spinal motion than I already have acquired from swing videos taken from multiple angles.
I am amazed that MD is willing to tolerate the badgering that KM and you inflict on him. I would find it more acceptable if KM's "qualitative" ideas were valid, but I think all that KM does in his articles is show how different golfers move different body parts differently. However, I think that his causal linking theories are incoherent/illogical - as I have repeatedly demonstrated. KM has no idea whether a movement is more likely to be active versus passive, or primary versus synergistic - because he doesn't understand the concept of the intact LAFW and the biomechanical/mechanical differences between a swinging technique versus a hitting technique. He also doesn't realize that a golfer can chose to be a right arm swinger versus a left arm swinger.
Jeff.
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Post by konrad on Sept 12, 2013 23:40:17 GMT -5
Jeff-
I acknowledge your diagrams and yes, by establishing that red line reference point, you can create a sequence of events where the left and right femurs are both in a ER orientation to that red line at some point in a simulated downswing. Problem is, I don't agree that scenario you illustrated is what Sam Snead is doing in that video.
I don't believe Snead's femur is in an IR orientation to his right side pelvis (your red line) at P4. His right leg straightens in the BS to a point where the femur is in a neutral orientation to his rotated pelvis. As Snead begins to rotate the pelvis counterclockwise between P4 and P5, his right thigh and knee move forward and inward and they keep pace with the right side pelvis and maintain that neutral orientation IMO. The femur doesn't reach an ER orientation with the right side pelvis until P5.5 and by then the left side pelvis has rotated to a point where the left femur appears to have an IR orientation to the left side pelvis, so "Dual ER" of the right and left femurs never actually takes place. Also, the right leg femur is in that ER orientation with the pelvis for only a split second. From P5.5 Snead's right leg and body are going into extension and that ER orientation of the femur disappears.
As for Jack Nicklaus, I do not agree with you that his right hip joint stays in a relatively stationary position between P4 and P5 and then his left buttocks moves back to the tush line like a closing door. Image 3 clearly illustrates that his right pants pocket is in a completely different location than it was in image 2. From P4 to P4.5 (P4.7 by your estimation) Jack has moved his right hip and thigh forwards towards the ball target line and his right knee has gone into flexion and also moves forward and inward by that point. these movements of the hip, thigh and knee have continued to move further by image 4.
BTW, Happy Birthday Doc!
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Post by imperfectgolfer on Sept 12, 2013 23:49:22 GMT -5
See this Jeffy-forum thread - jeffygolf.com/showthread.php?794-Letter-to-the-Forum-When-Science-meets-BusinessI think that KM has gone off the deep end. What an irrational letter! I wonder why he is so defensive and antagonistic towards MD. I have not read any post by MD where he is plugging his software. Even if he has a business interest in 3-D technology, that doesn't mean he cannot participate in a debate re: golf swing biomechanics/mechanics. KM wrote-; " But don’t come in here and claim to be objective when you have hidden agendas or conflicts of interests." Where is there any evidence that MD's posts are contaminated by hidden agendas or conflicts of interest? KM wrote-: " Yet anyone with an open mind can easily see the validity and usefulness of the qualitative approach, to understanding the golf swing.." I agree that a qualitative approach has merit, but there are a variety of qualitative approaches eg. KM's versus BM's versus Bennett/Plummer's versus mine. Each proponent of a qualitative approach still has to defend the coherency of his approach with respect to explaining golf swing biomechanics/mechanics. I think that biomechanists have an important role to play if they can make precise measurements to test the validity of any theory (eg. my theory that a swinger should only use right arm push-pressure at PP#1 to synergistically increase the efficiency of release of PA#4 and PA#3, but that push-pressure should not be applied at PP#3 to attempt to speed-up the release of PA#2). My personal gripe with biomechanists is that they are not performing these measurements - even though the technology is available. They have the technology to subject my theory to experimental tests that could either verify or falsify my theory. The same applies to KM's theories eg. his theory that "DHers can close the clubface by using an early left arm supination maneuver and therefore avoid any need for the subsequent use of a PA#3 release action between P6.5 and P7" should be subjected to scientific testing. Jeff.
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Post by imperfectgolfer on Sept 13, 2013 0:40:51 GMT -5
Konrad,
My diagram wasn't based on a simulated downswing. It was based on Sam Snead's real life swing - as viewed in those 4 images.
You wrote-: "I don't believe Snead's femur is in an IR orientation to his right side pelvis (your red line) at P4. His right leg straightens in the BS to a point where the femur is in a neutral orientation to his rotated pelvis"
It is difficult to counter your argument because we are "apparently" seeing different visual "facts" when we look at the same image. I think that at address, SS's pelvis and anterior right thigh face the ball-target line. I think that his pelvis rotates about 50 degrees clockwise by P4, but I think that his anterior thigh rotates far less than 50 degrees, which means that his right femur must be internally rotated. The same "fact" applies to Jack Nicklaus - when I look at image 2, I think that his pelvis is rotated far more clockwise than the front of his right thigh. I think that this is the basis of Slicefixer's teaching principle of turning into one's right leg during the backswing - the word "into" implies internal rotation of the right thigh relative to the pelvis. In other words, I believe that one can only use the "turn into" backswing action if one deliberately prevents the right thigh from over-rotating during the backswing action. What allows the pelvis to rotate more than the right femur is the anatomical alignment of the right femoral neck/head and the fact that the hip joint is a ball-and-socket joint.
You also wrote-: "As Snead begins to rotate the pelvis counterclockwise between P4 and P5, his right thigh and knee move forward and inward and they keep pace with the right side pelvis and maintain that neutral orientation IMO"
I disagree? I see very little counterclockwise rotation of the front of SS's right knee and right anterior thigh between P4 and P5 in those 4 images, but I see the pelvis rotate counterclockwise by about 50 degrees.
You also wrote-: "From P5.5 Snead's right leg and body are going into extension and that ER orientation of the femur disappears."
I agree that the ER disappears - I think that SS's right leg becomes more neutral after P5.5 because the right leg becomes progressively more unweighted and it allows the right leg to rotate faster than the pelvis.
You also wrote-"As for Jack Nicklaus, I do not agree with you that his right hip joint stays in a relatively stationary position between P4 and P5 and then his left buttocks moves back to the tush line like a closing door. Image 3 clearly illustrates that his right pants pocket is in a completely different location than it was in image 2.
I think that JN's right hip joint is primarily moving away from the target in the early downswing - (compare image 3 to image 2) - and I think that there is very little outward motion towards the ball-target line. I think that his right buttocks is still rubbing against the glass wall of the tush line. I think that his right buttocks leaves the tush line between P5 and P6 (image 4).
See this Shawn Clement video where the glass mirror represents the tush line.
At the end of the video, you get an upline view which shows how the right buttocks remains against the glass mirror while the left buttocks gets pulled back to the glass mirror. By the way, I don't like SC's technique because he moves his pelvis too far laterally in the early downswing and that causes his right thigh to slant too much. I think that Hogan's "left hip clearing action" should be a more rotary motion with very little left-lateral pelvic shift.
Jeff.
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Post by imperfectgolfer on Sept 13, 2013 11:21:07 GMT -5
Konrad wrote-: " I don't believe Snead's femur is in an IR orientation to his right side pelvis (your red line) at P4. His right leg straightens in the BS to a point where the femur is in a neutral orientation to his rotated pelvis." Konrad believes that SS's right femur is neutral to the pelvis at the P4 position. I don't see that at all. Here are side-view images of Sam Snead at the P4 position. I agree that SS allowed his right leg to straighten during his backswing action, and that he rotated his right femur clockwise. However, I still believe that relative to his pelvis, that his right femur is internally rotated at the P4 position - because he had such a large amount of pelvic rotation. That gives him that "turned-in" look. By contrast, Rickie Fowler doesn't turn his right thigh clockwise very much in his backswing action and he doesn't have much pelvic rotation either (relative to Sam Snead). However. he also has that "turned-in" look at the P4 position - because his degree of clockwise rotation of the pelvis exceeds the degree of clockwise rotation of his right thigh. I think that RF's right thigh is internally rotated at the P4 position. Jeff.
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Post by imperfectgolfer on Sept 13, 2013 22:11:52 GMT -5
KM/Jeffy continue to attack MD in an overtly malicious and unjustified manner in the Jeffy forum thread - even though MD has seemingly behaved ethically. The pair of them are manifesting disgustingly uncivilized behavior!
Jeff.
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Post by konrad on Sept 13, 2013 22:26:45 GMT -5
KM/Jeffy continue to attack MD in an overtly malicious and unjustified manner - even though MD has seemingly behaved ethically. The pair of them are manifesting disgustingly uncivilized behavior! Jeff. That kind of behavior can be expected from Martin, but not from Miyahira. MD has done everything he can in a civil manner to get the conversation back to discussing the golf swing. KM appears to have two personalities on the internet and the dark side half is being revealed at the Jeffy golf forum. The exchange between KM and MD has been like watching a cat pawing a near dead mouse on the front porch. KM has been reduced to writing a childish rant because I don't think he can maintain the level of intellect MD possesses. KM must feel like he's on an island and nobody of importance is listening. The lonely voice of reason is not being taken seriously and his demands are not being met. Must be very frustrating for him.
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Post by konrad on Sept 13, 2013 23:28:07 GMT -5
Jeff,
Correct, a simulation (imitate the appearance of) of Sam Snead's swing in the B&W video.
I believe Slicefixer's principle of "turning into the right leg during the BS" was more about avoiding a sway of the hips to the right and getting too much weight onto the outside of the right foot. Don't believe he was specifically talking about getting the right femur into an IR orientation to the pelvis by P4. JMHO
If you want to establish that Snead's femur was in IR at P4 I have no problem excepting your conclusion based on your visual evidence of captured still photos from other Snead swing videos. My comment that Snead wasn't in IR at P4 referred directly to the B&W video swing . If Snead was in IR at P4 in the B&W video, I'll bet it wasn't by very much.
You wrote; "I think that SS's right leg becomes more neutral after P5.5 because the right leg becomes progressively more unweighted and it allows the right leg to rotate faster than the pelvis."
I wholeheartedly agree, but I don't think it happened in a gradual progression, I believe it happened pretty early in the DS and in a brisk manner.
I believe Snead didn't have nearly as much weight on his right foot as some people seem to think during the DS. I think this perception is because of the "squat move" which implies maintaining weight on the right leg/foot which would be needed for Dual ER IMO. If you saw Snead in person you would have easily noticed how fast he got the weight over to his left side in the DS. He unweighted the right leg/foot well before impact.
The "squat move" look was caused by the aggressive lateral movement of the left knee towards the target and the right knee going into flexion right away from P4. If you toggle that B&W video back and forth from P4 to impact you will see how his right hip and knee move forward and inward in a continuous motion all the way to impact. My point is, Snead had a very active lower bower body and was not trying to create a ground force in his right foot/leg that would create a Dual ER position somewhere before impact, especially in that B&W video swing.
As for Jack, if you believe his right buttocks is still on the tush line in image 3, then his right buttocks MUST have smashed through that line at P4. As I said, IMO from looking at those images he is definitely moving that right hip, thigh and knee forward towards the ball target line from image 2 to image 3. The movements from P4 to impact are continuous and they happen rapidly. Again, IMO Jack was making every effort to rotate his hips counterclockwise as fast as he could before impact, so the idea of keeping the right buttocks back against the tush line (whatever that really is) for any extended period of time would be counterproductive to generating a high rate of counterclockwise velocity of the hips prior to impact. It's the reason Jack was as long as he was with all clubs.
Here are several swings of Jack and if you look closely you will see how the right buttocks did not stay back at all, it got moving forward toward the ball target line right from P4.
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Post by chipitin on Sept 14, 2013 16:40:08 GMT -5
It is a total joke what Kelvin M and Jeffy are trying to do to Mike D. The latest from Kelvin shows what kind of person he is, vindictive.
Mike wants to discuss golf and these two jerks want to try and use intimidation tactics against Mike. They have no real interest in golf biomechanics or really in anything except their personal agenda's.
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Post by imperfectgolfer on Sept 14, 2013 18:15:17 GMT -5
Konrad, You wrote-: " I believe Slicefixer's principle of "turning into the right leg during the BS" was more about avoiding a sway of the hips to the right and getting too much weight onto the outside of the right foot. Don't believe he was specifically talking about getting the right femur into an IR orientation to the pelvis by P4. I agree that Slicefixer was mainly interested in preventing a pelvic sway motion to the right. However, to accomplish that goal, a golfer needs to avoid allowing the right thigh to move away from the target and he must keep the right leg firmly grounded by applying dynamic weight-pressure down to the right foot. That biomechanical phenomenon of "firming-up" the right leg prevents the right thigh from over-rotating clockwise and it therefore rotates less than the pelvis. The end-result must be IR of the right thigh at P4 to a variable degree (less in Sam Snead compared to a Slicefixer student eg. Spider) Spider swing videos U-tube rear-view overhead video U-tube front-view overhead video You also wrote-: " If you want to establish that Snead's femur was in IR at P4 I have no problem excepting your conclusion based on your visual evidence of captured still photos from other Snead swing videos. My comment that Snead wasn't in IR at P4 referred directly to the B&W video swing . If Snead was in IR at P4 in the B&W video, I'll bet it wasn't by very much.I agree that it wasn't by much because SS allowed his right thigh to rotate a lot clockwise between P1 and P4. You also wrote-: " I believe Snead didn't have nearly as much weight on his right foot as some people seem to think during the DS. I think this perception is because of the "squat move" which implies maintaining weight on the right leg/foot which would be needed for Dual ER IMO. If you saw Snead in person you would have easily noticed how fast he got the weight over to his left side in the DS. He unweighted the right leg/foot well before impact". I agree that SS got onto his left side well and that he unweighted his right leg well before impact - but he did not do those two things before P5. At P5 (hip-square position), he was squatting with his dynamic weight-pressure roughly balanced equally between his two feet. You also wrote-: " My point is, Snead had a very active lower bower body and was not trying to create a ground force in his right foot/leg that would create a Dual ER position somewhere before impact." The situation of a dynamically weighted right leg/foot, where most of the dynamic weight-pressure is on the right leg/foot (relative to the left leg/foot), only exists at P4 and at the start of the transition. It disappears progressively between P4 and P5, and by P5 the dynamic weight-pressure is roughly equally distributed between the two legs. By that time, the left buttocks is already pulled back to the tush line and the pelvis is square. I think that Jack Nicklaus kept his right buttocks against the tush line at the transition for far less time than many PGA tour golfers - like Phil Mickleson and Bradley Keegan. See Q&A number 7 in my downswing chapter. perfectgolfswingreview.net/downswing.htmJeff.
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Post by konrad on Sept 14, 2013 18:52:18 GMT -5
I still don't think Snead was in Dual ER. It's not something to strive for in a golf swing IMO.
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Post by imperfectgolfer on Sept 14, 2013 20:40:21 GMT -5
See this Jeffy-forum thread - jeffygolf.com/showthread.php?799-Mike-Duffey-and-QualysisKelvin's hypocrisy is unbelievable. If KM and Jeffy want to stop MD from posting in Jeffy's forum, they should just ban him. MD is behaving in a very civilized manner, despite KM's endless provocations, and he is showing KM to be a panic-stricken bully who just wants to taunt MD, and who doesn't want to really debate MD about golf swing biomechanics. Jeffy adds his clownish comments by asking MD why he doesn't discuss "X", "Y" or "Z" in a forlorn attempt at one-upmanship. If he believes that KM's 130-micromoves are critical to a good golf swing, then he should provide a counterargument that MD can respond to in a constructive manner. I, of course, believe that those micro-moves are minor swing elements and I believe that KM/Jeffy don't grasp the "true" biomechanical/mechanical fundamentals underlying a full golf swing. I wonder why KM feels so threatened by a counterargument? Jeff.
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Post by imperfectgolfer on Sept 14, 2013 20:53:45 GMT -5
Konrad,
You wrote-: "I still don't think Snead was in Dual ER. It's not something to strive for in a golf swing IMO."
I am baffled by your "belief" that SS was not in dual-ER at P5 when he was in his "sit-down" downswing posture - when his pelvis was square to the ball-target line, and when both of his anterior thighs were slightly rotated outwards (away from the body).
I don't think that a golfer has to strive for dual-ER - he merely needs to strive to perform his downswing action as previously described, and there will likely be a fractional moment-in-time when he will be in dual-ER (when he is momentarily in the hip-squaring phase, which usually happens at ~P5) presuming that he doesn't have too much left-lateral pelvic sway motion in his early downswing.
Jeff.
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Post by konrad on Sept 14, 2013 21:40:22 GMT -5
That was supposedly written by a "colleague" of Miyahira and Martin. I thought the below comment in bold print is both revealing and accurate. "Why would he risk the possibility of any negative consequences just because he so dearly wants to "one-up" a mere golf pro and his cohort in an online "infotainment" forum in retaliation for them exposing him. Not exactly high praise, especially from a "trusted" colleague. I don't understand how this "colleague" can say that Miyahira and Martin have exposed MD. Exposed what? That he's twice as smart as KM and JM put together? Isn't it glaringly obvious that trying to "one-up" people on the internet is KM's and JM's MO?
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Post by imperfectgolfer on Sept 14, 2013 23:13:15 GMT -5
I am also in the business of trying to 'one-up' other golf instructors/theorists (like KM and BM), and/or biomechanists, but I focus my attack on their opinions re: golf swing biomechanics/mechanics. I don't attack their professional work arrangements (eg. like KM/Jeffy are attempting to do with respect to the nature, and practice, of MD's professional life as an university-affiliated researcher) because that has nothing to do with golf swing biomechanics/mechanics. I don't mind if KM/Jeffy try to 'one-up' MD with respect to their respective understanding of golf swing biomechanics/mechanics. However, KM/Jeffy never compare their thinking about golf swing biomechanics versus MD's thinking by providing concrete examples. They simply imply that they know much more than MD about 130 micro-moves. But, they are not even attempting to show that any of those micro-moves are fundamentally critical to a good golf swing and that MD is not capable of measuring those biomechanical movements. Pathetic!
Jeff.
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