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Post by imperfectgolfer on Jul 14, 2017 6:15:31 GMT -5
DubiousGolfer,
I noted that Phil Cheetham replied promptly to your e-mail message. So, why don't you send him a link to the GolfWRX thread and ask him why there is a marked discrepancy between his PhD dissertation's 3-D findings (where the left wrist becomes increasingly flexed between P6 and impact) and Dan Carraher's 3-D findings (where the left wrist becomes increasingly extended between P6 and impact in ALL pro golfers except Daniel Berger)?
Jeff.
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Post by dubiousgolfer on Jul 14, 2017 9:04:36 GMT -5
Funnily enough I already sent him an email earlier today and awaiting his reply . When he does I will copy him your question above although I did promise not to bother him again. My questions were quite simple.
2. Do ALL PGA Pro golfers extend their lead wrist (ie' more flexion to less flexion) through impact. 3. Can current 3D technology do measurements that can validate point 1 from 'impact/post impact(for a few inches)'.
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Post by imperfectgolfer on Jul 14, 2017 13:38:24 GMT -5
Funnily enough I already sent him an email earlier today and awaiting his reply . When he does I will copy him your question above although I did promise not to bother him again. My questions were quite simple. 2. Do ALL PGA Pro golfers extend their lead wrist (ie' more flexion to less flexion) through impact. 3. Can current 3D technology do measurements that can validate point 1 from 'impact/post impact(for a few inches)'. It puzzles me that you would ask him those questions, which are phrased in such a confused manner. His personal research study on 94 professional golfers showed increasing left wrist flexion in the late downswing - and not increased left wrist extension. You should have specifically stated that other 3-D studies have come to exactly the opposite conclusion and then you should have asked him why do these contrary study results exist. Jeff.
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Post by imperfectgolfer on Jul 14, 2017 16:52:36 GMT -5
Dan Carraher posted this very informative image in the GolfWRX thread. Dan claimed that the left wrist was 9 degrees flexed at impact and then 7 degrees flexed at P7.4. That represents a change of only 2 degrees of left wrist flexion in the direction of left wrist extending (which is functionally insignificant) between P7 and P7.4. That proves my point that if the clubshaft does not bypass the left arm through the immediate impact zone between P7 and P7.2 then there must only be an insignificant amount of left wrist extending (which I arbitrarily defined as <5 degrees) happening during that time period. That's what a DH-hand release action is all about, and this golfer would fit my definition of being a DHer who can maintain a stable clubface through the immediate impact zone by avoiding any significant left wrist flipping! This golfer also disproves Dan Carraher's often-repeated claim that all pro (or skilled) golfers are rapidly and massively extending their left wrist through impact! Jeff.
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Post by dubiousgolfer on Jul 14, 2017 17:42:08 GMT -5
I think your correct that there is insignificant amount of left wrist flexion (in the direction of extending) but iteach says 'rapidly extending' which I think is the rate at which it has moved those 2 degrees. So are you both correct?
With regards the email to Dr Cheetham , I did add the following:
The reason I am asking these questions is that there seems to be a marked discrepancy between your PhD dissertation's 3-D findings (where the left wrist becomes increasingly flexed between P6 and impact) and Dan Carraher's 3-D findings (where the left wrist becomes increasingly extended between P6 and impact in ALL pro golfers except Daniel Berger)?
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Post by imperfectgolfer on Jul 14, 2017 18:57:59 GMT -5
I am so delighted that Dan Carraher posted this image of the 3-D results of one of his student golfers - because that golfer perfectly exemplifies my golf teaching philosophy. I cannot thank Dan Carraher enough for posting this image! This golfer is a perfect example of a DHer and he only has 2 degrees of "left wrist extending" happening between P7 (where his left wrist is 9 degrees flexed) and P7.4 (where his left wrist is 7 degrees) flexed. That's a remarkably good result because that means that the golfer is keeping his left wrist (and therefore clubface) very stable to well beyond the end of the immediate impact zone (which ends at P7.2) and he is avoiding any significant "left wrist extending" motion from happening during that long followthrough time period where the clubhead has traveled ~2-3' along the clubhead arc between impact and P7.4. That's exactly the type of hand release action that I promote in my 7-hour long video project on "How to Perform a Golf Swing Like a PGA Tour Golfer". In that video project, I promoted two ideal full golf swing techniques. The first technique is an intact LAFW technique where the golfer performs a drive-hold hand release action through the immediate impact zone by maintaining a GFLW between P7 and P7.2. That technique of drive-holding is based on "rhythm" where the golfer perfectly matches the forward angular velocity of his left arm to the forward angular velocity of the clubshaft so that the clubshaft does not bypass the left arm between P7 and P7.2 (or even better to P7.4). The second technique - based on a bowed (palmar flexed) left wrist - is even better because the biomechnical action of maintaining left wrist palmar flexion throughout the immediate impact zone between P7 and P7.2 adds an element of mechanical stability, which combined with the element of rhythmic stability, makes it even more likely that a golfer can be a DHer throughout the clubhead's travel passage time through the immediate impact zone. Dan Carraher's golfer is a perfect example of this technique because he maintains a palmar flexed left wrist all the way between P7 and P7.4 and he still has a significantly palmar flexed left wrist at P7.4 (where his left wrist is still 7 degrees palmar flexed). I described two subtypes of this second technique in my video project. The 1st subtype is exemplified by Jordan Spieth (and also Dustin Johnson and Jon Rahm) because they acquire a bowed left wrist during their backswing action and they maintain a bowed left wrist all the way between P4 and P7.2+. Their degree of bowing (degree of left wrist palmar flexion) changes during the downswing and it often reaches its maximum value of palmar flexion between P5.5 and P6.2 as their hands "turn around the corner" and then it decreases significantly in the late downswing. However, they still maintain a palmar flexed left wrist between P7 and P7.2 and they avoid a significant amount of "left wrist extending" (which I arbitrarily define as <5 degrees) between P7 and P7.2. The 2nd subtype is exemplified by Gary Woodland (and David Toms) because they convert from a GFLW to an AFLW (palmar flexed left wrist) during their mid-downswing, and they also have their greatest degree of left wrist palmar flexion happening between P5.5 and P6.2 as their hands "turn around the corner". Then, their left wrist becomes less palmar flexed in their late downswing, but they are still palmar flexed at impact. They then prevent any significant amount of "left wrist extending" from happening (which I arbitrarily define as < 5 degrees) between P7 and P7.2. Dan Carraher's student golfer seems to fit into this 2nd subtype because his left wrist appears to be extended (dorsiflexed) at his end-backswing position and it then moves towards becoming palmar flexed by his mid-downswing. I cannot exactly determine (from the graph) where his left wrist reaches its maximum degree of palmar flexion, but Dan Carrher stated that it is 23 degrees palmar flexed at P6. Then, (like Jordan Spieth or Gary Woodland) it becomes less palmar flexed during the late downswing, but it is still significantly palmar flexed (9 degrees) at impact. Finally, he is a perfect DHer because he only allows his left wrist to extend by 2 degrees (which is an insignificant amount) between P7 and P7.4! For those who are interested, I described this 2nd subtype of a bowed left wrist technique in part 7 of my video project ( youtu.be/MzW3eCrM5KU ) and I also described it in a number of my review papers eg. see topic number 8 of this review paper ( perfectgolfswingreview.net/2014Revision.htm ). Jeff.
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Post by imperfectgolfer on Jul 14, 2017 19:03:26 GMT -5
I think your correct that there is insignificant amount of left wrist flexion (in the direction of extending) but iteach says 'rapidly extending' which I think is the rate at which it has moved those 2 degrees. So are you both correct? With regards the email to Dr Cheetham , I did add the following: The reason I am asking these questions is that there seems to be a marked discrepancy between your PhD dissertation's 3-D findings (where the left wrist becomes increasingly flexed between P6 and impact) and Dan Carraher's 3-D findings (where the left wrist becomes increasingly extended between P6 and impact in ALL pro golfers except Daniel Berger)? DB, You asked-: " I think your correct that there is insignificant amount of left wrist flexion (in the direction of extending) but iteach says 'rapidly extending' which I think is the rate at which it has moved those 2 degrees. So are you both correct?" No! The left wrist cannot be rapidly extending if its degree of palmar flexion only changes by 2 degrees over such a prolonged time period between P7 and P7.4 (where the clubhead has traveled about 2-3 feet along the clubhead arc). In fact, it is happening ultra-slow and that "fact" allows Dan Carraher's student golfer to be a perfect DHer! Jeff.
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Post by dubiousgolfer on Jul 14, 2017 20:58:01 GMT -5
Okay - that makes sense although the amount of condescending remarks from GOLFWRX members for just debating golf issues with their pros is not nice.
So was Cheethams graph misleading because I thought the vertical green line marked 'Release' point (but apparently it doesn't exist according to Iteach and it represents the P5 position, not P6 - the avatar picture is a representation of the green line I think).
So is there still a contradiction between Iteach and Cheetham's graphs from P6 to impact ? I suspect it would be easier if there was P6 line on the Cheetham graph but I suspect it will still show increased flexion happening rather than increased extension.
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Post by imperfectgolfer on Jul 14, 2017 22:00:58 GMT -5
Okay - that makes sense although the amount of condescending remarks from GOLFWRX members for just debating golf issues with their pros is not nice. So was Cheethams graph misleading because I thought the vertical green line marked 'Release' point (but apparently it doesn't exist according to Iteach and it represents the P5 position, not P6 - the avatar picture is a representation of the green line I think). So is there any contradiction between Iteach and Cheetham's graphs? Here is Cheetham's graph. You asked-: " So was Cheethams graph misleading because I thought the vertical green line marked 'Release' point (but apparently it doesn't exist according to Iteach and it represents the P5 position, not P6 - the avatar picture is a representation of the green line I think)." Dan Carraher is clueless when it comes to correctly interpreting graphs! He totally misinterpreted this Cheetham graph and also the Sweeney graph (because he originally assumed that it was representing increasing left wrist extension) and then he finally had to admit that he was wrong. That vertical green line is the club release point, which happens at ~P5.5 in most PGA tour golfers, and that avatar is much closer to P5.5 (and not P5). One obviously knows that the vertical green line represents the club release point because that's when the left wrist starts rapidly ulnar-deviating (see the sharp rise in the steepness of the red graph line starting at the release point). You also asked-: " So is there any contradiction between Iteach and Cheetham's graphs?" Of course! They are totally different. Note that the green graph line in the Cheetham graph image shows that the left wrist is slightly extended at the release point, and it then becomes increasingly positive during the remainder of the downswing indicating that the left wrist is moving towards a greater degree of left wrist flexion such that the left wrist reaches its maximum degree of palmar flexion (~21 degrees palmar flexed) just before impact. Here is Dan Carraher's student's graph. By contrast, in Dan Carraher's graph of the student golfer, the left wrist is about 10 degrees extended at the club release point (which is the point when the left wrist starts to ulnar-deviate rapidly - see orange graph) and it then rapidly becomes frankly palmar flexed so that it reaches its maximum degree of palmar flexion of 23 degrees (see peak of the green graph) at some time point in the later downswing (eg. P6) before becoming dramatically less palmar flexed during the remainder of the downswing so that it is only 9 degrees palmar flexed at impact. Jeff.
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Post by imperfectgolfer on Jul 14, 2017 23:00:53 GMT -5
bph7 wrote the following in the GolfWRX thread-: " Having read the thread over on jeff's board, the mistake he is making is in only considering the amount of extending from p7 to p7.4. What the graph is showing is extension from p6 onward. It's a big difference because impact itself is going to counteract some of the extending. He's basically not looking back far enough in the swing (to p6) to see what fwp, Dan, Monte etc are saying. He's cherry picking the data to support his case. He's not really wrong about p7 to p7.4, during which he even admits there's some extension, but it's not the same discussion that the teachers on here are trying to have." I disagree that I am cherrypicking the data. I think that bph simply does not understand my thinking on hand release actions. I am only considering the P7 => P7.4 time period (and not the pre-impact time period) because my drive-hold (DH) hand release concept only starts at impact and I have defined the immediate impact zone as the time period between P7 and P7.2. I have stated that if a golfer can maintain a stable clubface between P7 and P7.2 such that the clubface remains square to the clubhead arc during that time period, then he is a DHer. I have also stated that an important clue that suggests that a golfer is a DHer is the "fact" that the clubshaft does not bypass the left arm during that time period, and that necessitates keeping the left wrist from significantly extending (which I arbitrarily define as being < 5 degrees of left wrist extending) during that time period. I believe that skilled golfers use three swing element techniques to achieve that goal - i) A rhythm element where they match the angular velocity of the forward motion of their left arm to the forward angular velocity of the clubshaft during that time period; +/- ii) a mechanical element where they may also choose to palmar flex their less wrist using muscles in their left forearm and iii) they simultaneously avoid applying any push-pressure below the coupling point secondary to actively straightening their right wrist in a slap-hinge manner. I don't believe that the impact collision event has any significant effect on a golfer's ability to maintain a GFLW (or an AFLW) through impact! If it did, then amateur golfers would not have a flipping problem. I have no idea why bph7 is talking about the P6 => P7 time period (which represents the late downswing) because I have never talked about that late downswing time zone when it comes to the topic of hand release actions through the immediate impact zone. I am aware that Cheetham's 3-D findings (where the left wrist becomes increasingly flexed during the later downswing reaching its maximum degree of palmar flexion just before impact) is totally different to Dan/FWP 3-D findings (where the left wrist reaches its maximum degree of palmar flexion at about P6 and then becomes dramatically less palmar flexed during the remainder of the downswing). I have theorized that it is due to two different swing techniques - eg. a TGM handle-dragging ("sustain the lag") TGM swinging technique in Cheetham's studied pro golfers and the swing technique of "combined early left forearm supination and left wrist palmar flexion" (as described in topic number 8 of this review paper at perfectgolfswingreview.net/2014Revision.htm ) in Dan Carraher's studied pro golfers. However, I am still open minded about this issue (which has nothing to with my DH-hand release topic) and I am willing to entertain alternative biomechanical/mechanical explanations. Also, looking back at the first page of the GolfWRX thread, the real criticism of me started with this comment by Fort Worth Pro-: " I was more concerned with the flat left wrist and no bending. The lead wrist is extending rapidly through impact." That was the original targeted criticism that started the shameful saga of relentlessly attacking me when I could not respond directly, and I have since shown that Fort Worth Pro's opinion that the left wrist is extending rapidly through the immediate impact zone between P7 and P7.2 to be incorrect in a DHer (like Dan Carraher's student golfer). Jeff.
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Post by dubiousgolfer on Jul 15, 2017 7:11:15 GMT -5
I've just been reviewing quickly through Dr Cheetham's dissertation and on page 40 it says the following: --------------------- 92 of the 94 had positive lead wrist extension velocities at impact. This is the case because lead wrist flexion-extension velocity changed from flexing to extending just milliseconds before impact in these golfers, but it is important to note however, that at impact the lead wrist had a mean value of 2° of flexion for the entire group. -------------------
So isn't that enough proof that many pro golfers are demonstrating very little extension through impact (no rapid extension).
Incidentally , in terms of the sensors being used for measurements, is an APOR state of the lead wrist = zero 'flexion/extension' ?
PS. If Cheetham has mentioned that at impact the lead wrist had a mean value if 2 degrees flexion for the entire group, why isn't that represented on his graph?
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Post by imperfectgolfer on Jul 15, 2017 8:12:01 GMT -5
I've just been reviewing quickly through Dr Cheetham's dissertation and on page 45 it says the following: --------------------- 92 of the 94 had positive lead wrist extension velocities at impact. This is the case because lead wrist flexion-extension velocity changed from flexing to extending just milliseconds before impact in these golfers, but it is important to note however, that at impact the lead wrist had a mean value of 2° of flexion for the entire group. ------------------- So isn't that enough proof that many pro golfers are demonstrating very little extension through impact (no rapid extension). Incidentally , in terms of the sensors being used for measurements, is an APOR state of the lead wrist = zero 'flexion/extension' ? That comment by Phil Cheetham that the lead wrist starts extending milliseconds before impact has no scientific validity because it is simply a "best fit" phenomenon seen in his flexion-extension graph. I contacted Phil Cheetham about this point and he conceded that he was wrong to make that claim and he conceded that his 3-D system (which only captures a single data point every 4-8" of hand travel at/near impact) cannot possibly capture what is happening at impact. However, we do have substantial proof that the lead wrist is not signficantly extending between P7 and P7.2 in DHers - based on Dan Carraher's 3-D results in his student golfer and based on Phantom camera images of a DHer (eg. John Oda's swing capture by Kelvin Miyahira). Jeff.
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Post by dubiousgolfer on Jul 15, 2017 8:25:33 GMT -5
Many thanks for explaining this to me .
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Post by imperfectgolfer on Jul 15, 2017 9:50:59 GMT -5
I have demonstrated (using the 3-D results from Dan Carraher's student golfer) that the left wrist does not extend significantly between P7 and P7.2 in a skilled golfer who is a DHer. That student golfer only had 2 degrees of "left wrist extending" happening between P7 and P7.4, which will probably work out to 1 degree between P7 and P7.2 (which is negligible). That "fact" disproves the wrongheaded "belief" that the left wrist rapidly and massively extends through impact (between P7 and P7.2) in a DHer. The question then becomes - what do long-drive competitors do between P7 and P7.2 when they drive the ball >400 yards? Are they DHers or non-DHers? Surprisingly, many world champion long-drive competitors are DHers, and they do not allow the clubshaft to bypass their left arm between P7 and P7.2 (which means that the left wrist is not significantly extending between P7 and P7.2). I am very familiar with the golf swings of long-drive competitors because I was contacted by Lee Cox (coach of Joe Miller who won the 2016 World Long Drive competition) about 2 years ago. Lee Cox is a big fan of my golf website and he contacted me seeking advice on how Joe Miller could change his golf swing biomechanics so that he could generate a higher clubhead speed at impact. I studied a number of Joe Miller's swing videos and I then offered Lee Cox some advice, which Joe Miller incorporated into his golf swing action. The result was that his average clubhead speed went up from 145mph to 150-155mph and Joe won the 2016 World Long Drive competition with a drive of 439 yards. Lee Cox is also very familiar with other long-drive competitors and he recently sent me a video that he captured of Tim Burke's golf swing when Tim visited with Joe Miller in June 2017 at the Shire Golf Club in London, England (where Lee Cox is the chief golf instructor). Tim Burke won the 2014 and 2015 World Long Drive competition and Lee Cox believes that he is the best long-drive competitor in 2017 based on his currect form. Lee Cox also stated that he is probably the most accurate long-drive competitor at present, and I suspect that his accuracy is significantly due to the fact that he is a DHer. Here is Tim Burke's swing video (captured in slow motion with an iPhone). Here are capture images from the video. Image 3 is at impact - note that he has an AFLW and that the clubshaft is straight-in-line with his left arm. Image 4 is at P7.2 - note that he still has an AFLW and that the clubshaft has not bypassed his left arm, which means that he is a DHer even though his clubhead speed recorded during this swing video was 150mph. Tim Burke is such an efficient DHer that he prevents the clubshaft from bypassing his left arm to even well beyond P7.2. Here are DTL capture images of Tim Burke's swing. Note that Tim Burke still has an AFLW and that his clubshaft has not bypassed his left arm (from an angular rotational perspective) at P7.5 - see image 5. Note that his clubface is still square to his clubhead arc in that image (which is astonishing considering his ultra-fast clubhead speed at impact). In other words, it is a fallacy to believe that a long-drive competitor must rapidly and massively extend his left wrist through the immediate impact zone between P7 and P7.2 in order to maximize his clubhead speed at impact. The "real life" reality is that maximum clubhead speed at impact is best derived from the most efficient sequential release of PA#4 => then PA#2 and that one shouldn't attempt to allow the left wrist to extend rapidly through the immediate impact zone in a futile attempt to generate even more clubhead speed. That left wrist flipping action will not significantly increase clubhead speed, but it will much more likely result in a non-stable clubface through impact, that can potentially impair a golfer's ball flight accuracy. So, being a DHer (rather than a non-DHer) is even a very suitable choice for a long-drive competitor golfer. Jeff.
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Post by dubiousgolfer on Jul 15, 2017 17:00:28 GMT -5
Dr Mann
So with all this flexion and extension happening before impact, what happens to the TGM concept of the intact LAFW? Is it still a useful concept to aspire to? Further, if any flexion/extension is occurring in the lead wrist , can one still truly stay 'On Plane' as defined by TGM?
Personally , I find it easier to have an AFLW (which I think means some flexion) with my right arm swinging method (with a reactive pivot) and this doesn't seem to instill any need for any 'extra' left wrist flexion before impact. Plus my strikes are generally straight and my bad shots are only pulls/pushes.
Also , here is the reply I received from Dr Cheetham:
"Yes it is interesting to me. I'm just at a conference speaking this weekend so pretty busy but I'll try and get to it this evening or tomorrow and have a look tomorrow afternoon might be good because it seems strange to me that they should be such a contrast especially since we've been talking about the wrist for many many years with TPI and many instructors such as Jon Sinclair. And a flexion extension graph makes perfect sense when you look at through especially with the other two motions, radial ulnar deviation and pronation supination."
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