|
Post by imperfectgolfer on Jul 15, 2017 19:58:21 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." DB, You asked-: " 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?" Dan Carraher's graph of his student golfer shows that there is a change in the degree of left wrist flexion from 23 degrees at P6 to 9 degrees at impact (which amounts to 14 degrees of left wrist extending happening over that time period), and that is very typical of golfers who use the bowed left wrist (AFLW) type of downswing action as described in one of my previous posts. Golfers who bow their left wrist in their downswing (like Gary Woodland and David Toms and Jon Rahm and Tim Burke) tend to have their maximum degree of left wrist palmar flexion as they "turn the corner" (which is somewhere between P5.5 and P6.2) and then they extend their left wrist during the remainder of their downswing. When they come into impact, they still have a small degree of left wrist palmar flexion present. If they are DHers, who prevent the clubshaft from bypassing their left arm between P7 and P7.2 (or even better to P7.4), then they will have no further "left wrist extending" action happening during that post-impact time period. Remember that Dan Carraher's student golfer only had an insignificant degree of "left wrist extending" of a mere 2 degrees between P7 and P7.4 (and it has nothing to do with ball collision that doesn't really affect the proximal clubshaft or the hands/wrist, although it may cause significant deflection of the peripheral end of the clubshaft). The phenomenon of significant "left wrist extending" during the later downswing between P6 and P7 doesn't apply to golfers who use the intact LAFW technique (like Henrik Stenson, Adam Scott and Justin Rose) and I have never seen anybody present 3-D "evidence" that they are significantly extending their left wrist between P6 and impact. If they are also DHers (like Adam Scott) then they are obviously not extending their left wrist during the P7 to P7.2 time period as seen in the following capture image. I still want to understand why Phil Cheetham found that the 94 pro golfers in his study had an increased degree of left wrist flexion happening in their late downswing between P6 and P6.9+ (even though Dan Carraher foolishly cannot see that phenomenon happening in Cheetham's study - see post #195 in the GolfWRX thread where he stated-: " Funny as Cheetham's graph shows exactly what I stated. Left wrist begins extending prior to impact and then levels off/flexes slightly due to collision at impact and then continues extending.") Cheetham's graph does show some "left wrist extending" happening after P6.9+ (which is likely an artifact because Phil Cheetham's 3-D system cannot accurately measure flexion-extension changes over a short distance of a few inches (eg. between P6.9 and P7). I therefore still want to understand why the pro golfers in Cheetham's study had increased left wrist flexion happening between P6 and P6.9+ (and likely P7) while Dan Carraher authoritatively claims that all pro golfers are rapidly/massively extending their left wrist between P6 and P6.9+. Regarding the accuracy of measuring the change of the degree of left wrist extending happening at the exact moment of impact, 3-D systems are woefully inadequate. Dan Carraher wrote the following regarding his 3-D system-: " And on my system there are 18 data points from p6 where peak flexion occurs and where impact occurs. And there's 4 data points from p7 to p7.2.". If there are only 4 data points between P7 and P7.2, then are less than 2 data points between P6.95 and P7.05 and that's totally inadequate. Compare that scenario to these capture images of John Oda's hands moving through impact - which were recorded at a sampling rate of 8,200 FPS. I measured the left wrist's dorsiflexion angles in those capture images and there was no significant change through impact. People will obviously complain that parallax errors make measurements derived from 2-D images inaccurate, but I studied that effect by drawing lines on my hands prior to videoing my hands through impact and I demonstrated that the parallax distortion/error effect is extremely small and insignificant. Jeff.
|
|
|
Post by imperfectgolfer on Jul 15, 2017 20:50:12 GMT -5
FortWorthPro posted a graph in post #222 of the GolfWRX thread and he them made the following comment about that graph-: " This is the graph of a world class "drive holder". His lead wrist is clearly extending well before impact and continues to do so through impact until his arms are about shoulder high." Here is a copy of his graph (where I have added two red arrows) The first vertical red arrow shows the club release point where the left wrist starts to unlar-deviate and that happens around P5.5 => P6 in most pro golfers. The 2nd red arrow shows the PA#3 release time point when the left forearm starts to supinate fast in the late downswing. Note that the peak of the green graph (representing flexion-extension) happens after the 2nd red arrow, which means that it is happening very late in the downswing, and also note that that there is very little left wrist extending happening between the peak of the green graph and impact - compared to the graph of Dan Carraher's student golfer. So, this graph (which supposedly represents a world-class pro golfer who is also a DHer) contradicts FWP's wild claim that all pro golfers reach their peak degree of left wrist flexion at ~P6 and then rapidly/massively extend their left wrist between P6 and impact. Secondly, FWP foolishly thinks that it shows a significant amount of "left wrist extending" happening between P7 and P7.2. How many data points were captured between P7 and P7.2 in that graph and what were the actual measurments of left wrist flexion at each of those data points? In the absence of sound scientific data measurements, that type of crude 3-D graph is meaningless when it comes to clearly showing the degree of "left wrist extending" happening in a DHer! The only 3-D graph that I have so far found to be valid is Dan Carraher's 3-D graph of his student golfer, which showed 9 degrees of left wrist flexion at P7 and 7 degrees of left wrist flexion at P7.4 (which means that there was no significant "left wrist extending" happening during the immediate impact zone between P7 and P7.2). Jeff.
|
|
|
Post by dubiousgolfer on Jul 15, 2017 20:52:54 GMT -5
Many thanks again.
|
|
|
Post by imperfectgolfer on Jul 16, 2017 6:23:15 GMT -5
bph7 wrote the following in the GolfWRX thread.-: " Also, jeff's latest comments on his own board show he's moving the goalposts again. No one said ALL tour pros were extending, it's been said over and over that Daniel Berger is an exception. Second, he refuses to acknowledge the effect of the collision with the golf ball, which is significant. Third, he tries to fit everything into his definition of a DHer, a term that he didn't been come up with. Fourth, I don't see why he thinks anyone should care about how things fit into his definitions. He's not a teaching pro and does not have access to the tech of the people he's bashing." I disagree with every one of his irrational statements. He first claims that " No one said ALL tour pros were extending, it's been said over and over that Daniel Berger is an exception." That statement is totally irrational because he is claiming that they didn't state that all tour pro golfers are extending throughout the entire late downswing because they have repeatedy stated that Daniel Berger is an exception. If Daniel Berger is their only example of an exception, then they are implying that all the other tour professional golfers are extending during the entire late downswing (which is a totally false claim based on 3-D evidence from Cheetham's study of 94 pro golfers). He then states that " Second, he refuses to acknowledge the effect of the collision with the golf ball, which is significant". Where is the "evidence" that the clubface's collision of the ball is significant in affecting a golfer's ability to maintain a "left wrist extending" action through the immediate impact zone between P7 and P7.2? We know that ball collision causes peripheral clubshaft deflection, but there is ZERO evidence that it affects the motion of the hands through impact. Dan Carraher irrationally claims that the "left wrist extending" phenomenon is temporarily delayed immediately after impact due to ball collision. Where is the scientific evidence to support such an irrational claim? Does he think that ball collision caused his student golfer's "left wrist extending" phenomenon to be delayed to P7.4 (where it was only a miniscule 2 degrees different in its degree of left wrist flexion than it was at impact)? Addendum added later: I just recalled the experiment that was described on page 145 of Cochrane & Stubbs book "Search for the Perfect Golf Swing" where they created a hinged driver where there was a passive/free hinge in the clubshaft just above the clubhead. They found that the hinged club performed exactly the same as a standard club, and that the clubhead didn't even hinge back as a result of ball collision. They concluded that the clubhead was "functionally" disconnected from the clubshaft at impact and that when it struck the ball it acted like a free-flying object that has a finite mass and specific velocity and that it didn't transmit any force back to the hands. So, the idea that the left wrist's rate of "extending action" is temporarily impeded by ball collision is a totally meritless idea. He then states-: " Third, he tries to fit everything into his definition of a DHer, a term that he didn't been come up with.". I may not have come up with term "drive-hold" but I definitely have my own definitions of the term and my own explanations of the underlying biomechanics. I also know that many tour pro golfers are DHers, which allows them to maintain a stable clubface through the immediate impact zone between P7 and P7.2 and I think that's a great advantage. I am certainly not interested in promoting a non-DH hand release action. For example, look again at this graph posted by FWP. Note that the blue graph continues its steep rise through impact implying that the golfer is continuing to supinate his left forearm throughout the immediate impact zone between P7 and P7.2 and that's impossible if a golfer is a DHer (as explained in this short review paper at perfectgolfswingreview.net/VP9.html ) There are only two possibilities - the 1st possibility is that the "world-class" golfer is not really a DHer and FWP needs to post a swing video, or capture images, of his golf swing so that we can independently assess that "fact" or the 2nd possibility is that this graph has so few data points between P7 and P7.2 that one cannot even assess the "fact" that there is no left forearm supination and no left wrist extending happening during that P7 => P7.2 time period. Finally, bph7 irrationally wrote-: " Fourth, I don't see why he thinks anyone should care about how things fit into his definitions. He's not a teaching pro and does not have access to the tech of the people he's bashing." I may not have access to high tech equipment, but I at least understand how to interpret the results produced from high tech equipment (eg. 3-D graphs) while pros like Dan Carraher and FWP are far too ignorant to understand how to interpret those graphs in a scientifically valid manner. I have repeatedly asked for 3-D evidence that all pro golfers are "extending their left wrist" throughout their entire late downswing and throughout the immediate impact zone between P7 and P7.2, and the only graph that FWP can seemingly produce is the graph above (which is crudely insufficient in delineating what is really happening between P7 and P7.2). Jeff.
|
|
|
Post by dubiousgolfer on Jul 16, 2017 21:29:56 GMT -5
Dr Mann - I noticed your Addendum below. So if the clubhead is functionally disconnected from the clubshaft at impact, any extension through impact should have no effect on the ball. Is that correct? That until the clubhead is functionally re-connected to the clubshaft nothing the hands do can affect the clubhead? If the latter, then when does the clubhead functionally reconnect with the clubshaft?
Addendum added later: I just recalled the experiment that was described on page 145 of Cochrane & Stubbs book "Search for the Perfect Golf Swing" where they created a hinged driver where there was a passive/free hinge in the clubshaft just above the clubhead. They found that the hinged club performed exactly the same as a standard club, and that the clubhead didn't even hinge back as a result of ball collision. They concluded that the clubhead was "functionally" disconnected from the clubshaft at impact and that when it struck the ball it acted like a free-flying object that has a finite mass and specific velocity and that it didn't transmit any force back to the hands. So, the idea that the left wrist's rate of "extending action" is temporarily impeded by ball collision is a totally meritless idea.
|
|
|
Post by imperfectgolfer on Jul 16, 2017 22:06:09 GMT -5
Dr Mann - I noticed your Addendum below. So if the clubhead is functionally disconnected from the clubshaft at impact, any extension through impact should have no effect on the ball. Is that correct? That until the clubhead is functionally re-connected to the clubshaft nothing the hands do can affect the clubhead? If the latter, then when does the clubhead functionally reconnect with the clubshaft? Addendum added later: I just recalled the experiment that was described on page 145 of Cochrane & Stubbs book "Search for the Perfect Golf Swing" where they created a hinged driver where there was a passive/free hinge in the clubshaft just above the clubhead. They found that the hinged club performed exactly the same as a standard club, and that the clubhead didn't even hinge back as a result of ball collision. They concluded that the clubhead was "functionally" disconnected from the clubshaft at impact and that when it struck the ball it acted like a free-flying object that has a finite mass and specific velocity and that it didn't transmit any force back to the hands. So, the idea that the left wrist's rate of "extending action" is temporarily impeded by ball collision is a totally meritless idea. The intellectual concept of the clubhead being "functionally" disconnected from the clubshaft at impact (as expressed by Cochrane & Stubbs) doesn't mean that it's really disconnected from the clubshaft. It only means that if the clubhead strikes the ball during its passage through the impact zone, that the clubhead has enough mass and velocity to hit the ball without transmitting a reactive concussive force along the clubshaft back to the hands in such a manner that it will affect the forward motion of the hands. In other words, if you take a practice swing without a golf ball and then take another identical swing that actually hits the ball, that your hand motion through the immediate followthrough will be the same - presuming that you performed the identical swing motion from a biomechanical perspective and presuming that you struck the ball perfectly on the sweetspot. Many golfers who have solidly hit the ball on the sweetspot with absolutely perfect timing have often reported the "feeling" of pure effortlessness - as if they were simply taking a practice swing without the ball being present. I am a "hacker", but I have occasionally experienced that same pure "feeling" where the ball gets propelled forward like it has been shot out of a cannon and yet there was never even a sensation of the ball being struck by the clubhead. I only wish that I was skilled enough to experience that "feeling" more often! Jeff.
|
|
|
Post by imperfectgolfer on Jul 16, 2017 23:48:54 GMT -5
bph7 wrote the following in the GolfWRX thread-: If only Jeff knew whose graph that was that he was describing as "not a DHer". At that point, he'd see just how far off he is in basically everything he's saying. I know, but I'm not going to say, rather see him continue to show his total lack of understanding." Such stupidity! I cannot fathom how bph7 can misunderstand, and therefore misrepresent, what I was saying in my previous post regarding the graph presented by FWP. I never stated that the golfer was definitely a non-DHer, and I only stated that the following-: " Note that the blue graph continues its steep rise through impact implying that the golfer is continuing to supinate his left forearm throughout the immediate impact zone between P7 and P7.2 and that's impossible if a golfer is a DHer (as explained in this short review paper at perfectgolfswingreview.net/VP9.html ) There are only two possibilities - the 1st possibility is that the "world-class" golfer is not really a DHer and FWP needs to post a swing video, or capture images, of his golf swing so that we can independently assess that "fact" or the 2nd possibility is that this graph has so few data points between P7 and P7.2 that one cannot even assess the "fact" that there is no left forearm supination and no left wrist extending happening during that P7 => P7.2 time period."I have repeatedly noted many of the GolfWRX forum members are staggeringly unable to correctly perceive the true reality of any of my comments and they simply distort my comments to suit their ideological agenda. I am also not really surprised that they are not even aware of the biomechanics that underlie a DH-hand release action - because they are not even aware that it is possible to avoid any "left wrist extending" and any left forearm supination from happening between P7 and P7.2 (which are the chief biomechanical elements of a DHer). So, why are they totally unaware of these biomechanical elements? The answer is simple - they cannot really see what is happening between P7 and P7.2 in their crude 3-D graphs, which use a "best fit" algorithm to connect their insufficient number of data points to create curves that give the impression that the left wrist is extending and the left forearm is supinating in a non-interrupted/non-stop manner through impact into the followthrough. And, when they occasionally get a graph that shows no "left wrist extending" happening between P7 and P7.4 (as seen in Dan Carraher's student golfer's flexion-extension graph) they invent an irrational explanation (that ball collision temporarily prevented the left wrist from continuing to extend in a non-interrupted manner after impact) to explain the blip. I guess that I shouldn't really be astonished by their ignorance - considering that they live in a world of "alternative facts" when it comes to golf swing biomechanics/mechanics. Jeff.
|
|
|
Post by dubiousgolfer on Jul 17, 2017 4:29:36 GMT -5
Dr Mann - not sure whether this assists or not from trying to figure out more data points through impact (email and attachment below). Imho, these graphs still do not show the granularity required to confirm what is happening through impact . ---------------- Jon Sinclair.odt (696.46 KB) Attached is my ranges for my PGA Tour data base. I believe I have one of the strongest data bases in the world. Certainly I have the best players. I think you will find a lot of good in the TGM and a lot of things that just do not happen. Technology has moved us forward. I have only recorded 2 players that actually increase flexion through impact. It is only for a fraction though. Everyone else is rapidly going toward extension. The flying wedge might be an effective drill for some but is certainly not possible with any speed. The graph I attached is of a tour player and is a pattern I typically see. The numbers below are his positions with my data base ranges next to them. Let me know if you have questions. ------------- My added question: So even with this 3D technology , is it fast enough to confirm if any rapid extension is happening through impact from say P7- P7.2 ? That we are actually just extrapolating what is happening from whatever data point frequency the system can provide? Can we say for certain that there is rapid extension occurring through compression time and for a few inches post impact? So how many data points can one reasonably expect the system to provide from say P7-P7.2? ------------- Answer: Yes we are very sure. The extension is happening at 240 - 725 degrees per second as an average. AMM is taking 240 samples within that same second. It is very Accurate. I have confirmed it with other systems capturing at much higher rates. It would simplify your thoughts if you realize that a driver at that speed effectively weighs somewhere +/- 100lbs. Do you think anyone is strong enough to hold their wrist in position with that kind of weight moving that fast. On top of that far, before that point in the swing, the club is outracing the hands and if you were able to hold that position all you would be doing is slowing the club down. It would be extremely inefficient. -------------- My calculations therefore show that if a pro golfer's hand speed was average 25 mph through impact 25 miles x 1760 yds x 36 inches = 1584000 inches every 3600 secs (1 hour) Lets say the lead hand moves 8 inches post impact at 25mph this would take approx (3600/1584000) x 8 = 0.0023 x 8 = 0.0184 secs If there are 240 samples per second, then the number of measurements that can be taken from impact for about 8 inches in lead hand movement = 0.0184 x 240 =4.4160 So that confirms that there is indeed only about 4 data points that can be measured over a hand path distance of 8 inches after impact. There is still not enough data to confirm what is actually happening through impact even if it was double the frequency. -------------
|
|
|
Post by imperfectgolfer on Jul 17, 2017 8:56:27 GMT -5
Dr Mann - not sure whether this assists or not from trying to figure out more data points through impact (email and attachment below). Imho, these graphs still do not show the granularity required to confirm what is happening through impact . ---------------- Attached is my ranges for my PGA Tour data base. I believe I have one of the strongest data bases in the world. Certainly I have the best players. I think you will find a lot of good in the TGM and a lot of things that just do not happen. Technology has moved us forward. I have only recorded 2 players that actually increase flexion through impact. It is only for a fraction though. Everyone else is rapidly going toward extension. The flying wedge might be an effective drill for some but is certainly not possible with any speed. The graph I attached is of a tour player and is a pattern I typically see. The numbers below are his positions with my data base ranges next to them. Let me know if you have questions. ------------- My added question: So even with this 3D technology , is it fast enough to confirm if any rapid extension is happening through impact from say P7- P7.2 ? That we are actually just extrapolating what is happening from whatever data point frequency the system can provide? Can we say for certain that there is rapid extension occurring through compression time and for a few inches post impact? So how many data points can one reasonably expect the system to provide from say P7-P7.2? ------------- Answer: Yes we are very sure. The extension is happening at 240 - 725 degrees per second as an average. AMM is taking 240 samples within that same second. It is very Accurate. I have confirmed it with other systems capturing at much higher rates. It would simplify your thoughts if you realize that a driver at that speed effectively weighs somewhere +/- 100lbs. Do you think anyone is strong enough to hold their wrist in position with that kind of weight moving that fast. On top of that far, before that point in the swing, the club is outracing the hands and if you were able to hold that position all you would be doing is slowing the club down. It would be extremely inefficient. -------------- My calculations therefore show that if a pro golfer's hand speed was average 25 mph through impact 25 miles x 1760 yds x 36 inches = 1584000 inches every 3600 secs (1 hour) Lets say the lead hand moves 8 inches post impact at 25mph this would take approx (3600/1584000) x 8 = 0.0023 x 8 = 0.0184 secs If there are 240 samples per second, then the number of measurements that can be taken from impact for about 8 inches in lead hand movement = 0.0184 x 240 =4.4160 So that confirms that there is indeed only about 4 data points that can be measured over a hand path distance of 8 inches after impact. There is still not enough data to confirm what is actually happening through impact even if it was double the frequency. ------------- DB, A 3-D system operating at 240FPS is inadequate when it comes to accurately measuring the rate of "left wrist extending" happening between P7 and P7.2. I will likely only believe a 3-D system's results with a greater degree of certainty if they operate at a much higher sampling frequency - eg. greater than 1,000FPS and preferably 5,000FPS - when it comes to analysing what is really happening between P7 and P7.2. What is particularly problematic about those graphs posted in that odt page is that it compresses the P7 => P7.2 time period so that it is not visibly discernible in the graph and those graphs are therefore practically useless in discerning what is happening between P7 and P7.2. He wrote-: " It would simplify your thoughts if you realize that a driver at that speed effectively weighs somewhere +/- 100lbs. Do you think anyone is strong enough to hold their wrist in position with that kind of weight moving that fast. On top of that far, before that point in the swing, the club is outracing the hands and if you were able to hold that position all you would be doing is slowing the club down. It would be extremely inefficient." Complete nonsense! First of all, that 100lbs weight measurement (which is very transitory) is directed outwards away from the golfer in a CF-manner, and it is not happening in the plane of flexion => extension at impact (if a golfer has a neutral left hand grip). Also, on what basis is he claiming that the club is outracing the hands just prior to impact? It is obvious that the clubshaft is moving at the same angular (and not linear) velocity as the hands in a golfer who uses an intact LAFW technique in the late downswing and early followthrough. His claim that if a golfer attempts to match the angular velocity of the hands to the angular velocity of the clubshaft through impact, that it will slow down the club is totally nonsensical! Consider Tim Burke's (2014 and 2015 World Long-Drive Champion) left arm/hand and clubshaft motion through impact when he generates a clubhead speed of >150mph. Image 1 is at P6.5 and image 2 is at P6.7 and image 3 is at impact. Note that his left arm and clubshaft are traveling at the same angular velocity (but obviously not at the same linear velocity) because he has an intact LAFW alignment. At impact (image 3), his clubshaft is straight-in-line with his left arm and at P7.2 (image 4) it is still straight-in-line with his left arm - and this DH-hand release action (involving an intact LAFW alignment) is happening in a golfer who can drive the ball 400-450 yards! By the way, I don't need a 3-D system to see that Tim Burke's left wrist is not extending, and that his left forearm is not supinating, between P7 and P7.2 and that's why he can be a DHer. Also, note that his hands are moving <8" forward between P7 and P7.2 so there will be very few data points in a 3-D system operating at 240FPS. Jeff.
|
|
|
Post by imperfectgolfer on Jul 17, 2017 9:34:14 GMT -5
Dan Carraher wrote-: "It goes from 23* at p6 to 9* at impact and like I said previously the collision at impact will often cause it level off or increase in flexion post contact and then continue extending to 7* at p7.4"
Now, I have noted that they are introducing another variable "clubhead-turf" collision as an explanation for why Dan Carraher's student-golfer's left wrist temporarily stops extending between P7 and P7.4. That claim is easy to disprove. Dan Carraher should simply record that student golfer's driver swing without a ball, and without allowing the clubhead to touch the ground, using his 3-D system and I strongly suspect that he will get the same 3-D results if the student-golfer uses the same golf swing biomechanics and the same DH-hand release action through impact.
Jeff.
|
|
|
Post by imperfectgolfer on Jul 17, 2017 11:08:45 GMT -5
Bronson (who harbors a great deal of personal antipathy towards me and who is also one of the stupidest forum members at GolfWRX) posted an extract from a David Tutelman article in post#245 of the GolfWRX thread. In particular, he yellow-highlighted this David Tutelman comment-: " We came to this conclusion based on total work at each of the joints. But the researchers also have the torque-vs-time graphs for each joint (not published in the paper). They must also support this conclusion, because Nesbit writes, "Just before impact the wrists momentarily approximate a “free hinge” configuration as the golfer merely holds on to the club as its momentum carries it to impact. By the time impact is reached, all torque components are in opposite directions because the wrists cannot keep up with the rotational speed of the club at this time in the downswing." That is consistent with my conclusions in my article on hitting with the hands. In a private communication, Sasho MacKenzie has also supported this point, citing the torque-speed relationship whereby the faster a joint is turning the less torque it can exert."I can certainly agree with the general tenor of that paragraph that the wrists cannot easily keep up with the club through the late downswing and also through the immediate impact zone between P7 and P7.2. And that is why pro golfers, and many long-drive competitors like Tim Burke, are smart enough not to attempt to actively straighten their right wrist in a slap-hinge manner (which would bend the left wrist) through impact. Instead, they keep their left wrist's flexion angle unchanged through the immediate impact zone between P7 and P7.2 - as seen in images 3 & 4 below. However, they are also smart enough to ensure that their forward speed of left arm motion keeps up with the forward speed of their clubshaft between P7 and P7.2 from an angular rotational perspective, which allows them to be a DHer. Jeff.
|
|
|
Post by imperfectgolfer on Jul 17, 2017 15:50:45 GMT -5
Bronson's ignorance regarding golf swing biomechanics/mechanics is boundless. He wrote the following in the GolfWRX thread-: " I mean the guy just can't parse a simple explanation when Nesbit and Mackenzie and Tutleman and Jon Sinclair say the wrists can't keep up it means the club head is out racing the hands, he ignores all the real researchers and experts and a person who has the strongest data base and knows what's happening. And the fact that the shaft is doing a lot of flexing and torquing in different directions, leading and lagging don't exist in his LAFW world. He then admits the wrists can't keep up but then he equates that to top golfers not actively slapping at the ball with the trail wrist. To the Ignorant Dr.Mann When Nesbit and Mackenzie and any real researchers say "wrists" they mean both of them. Even a stupid poster like me understands that they mean the lead wrist also cannot keep up and that's without any slap action from the trail wrist!"
Nesbit and MacKenzie never stated that the clubhead would outrace the hands simply because the left wrist is a passive, free-hinge joint. They simply stated that the wrist torque forces are not working to move the clubshaft forwards as the club reaches near to impact because as Sasho MacKenzie states " citing the torque-speed relationship, whereby the faster a joint is turning the less torque it can exert." However, that's the great advantage of the intact LAFW swinging technique - one is not dependent on creating any wrist torque and one allows the club to release freely because the left wrist is a free-hinge joint that reacts passively to the interplay between the forward motion of the left arm relative to the forward motion of the clubshaft. So, Tim Burke can prevent the clubshaft from bypassing his left arm between P7 and P7.2 not by applying any left wrist torque (either negative or positive) - but by simply matching the forward angular velocity of his left arm to the forward angular velocity of the clubshaft in the presence of a passive, free-hinge left wrist joint. I am not surprised that Bronson (and certain other forum members in GolfWRX's "alternate fact" mental universe) cannot understand this simple concept of physical mechanics. Here are a few examples of pro golfers who can easily keep the clubshaft from bypassing the left arm between P7 and P7.2 - even though the left wrist is a free-hinge joint (that is free of any applied torques during the P7 => P7.2 time period). Justin Thomas Adam Scott Henrik Stenson Dustin Johnson Evidence that Bronson is totally ignorant of the biomechanics/mechanics underlying a drive-hold hand release action can be gleaned from this quote in post #250 of the GolfWRX thread where he states-: " Kelvin M who coined the term and his definition of what a DHER swing is ....A Drive Hold™ swing describes a golf swing that is driven by the spine and which enables the clubface to be held stable through impact."
Claiming that a spine-driven golf swing is the source of a golfer's ability to maintain a stable clubface through impact is a claim that reaches the highest pinnacle of pure ignorance!!!! Jeff.
|
|
|
Post by dubiousgolfer on Jul 17, 2017 17:06:57 GMT -5
Bronson used to be asterisk who is basically a 'Troll'. He will do his best to prolong heated debates using condescending and sarcastic remarks. Even to the extent of learning some golf articles and adding some authenticity to his posts. He probably hates all things golf and anyone connected with the sport , academic or otherwise.
|
|
|
Post by imperfectgolfer on Jul 17, 2017 19:09:04 GMT -5
bph7 wrote the following in post #264 of the GolfWRX thread-: " Who is saying a faster system wouldn't be better? Of course it would. However, as has been explained multiple times, AMM does have enough data points to show what is happening. If AMM was total garbage and just guessing, why do basically all tour pros exhibit many of the same characteristics? Is it just a huge coincidence? There is a better system than AMM that shows similar findings, btw. Jeff seems to think that since we can't get a certain fps, then the data is necessarily wrong. I just don't think that's the most productive way to approach this. We use the best tools we can and try to learn what we can. When better tools are available, we can re-evaluate and see if our findings need to change. How is that not a reasonable approach? Jeff seems to be so far backed into a corner that his only argument is that, since the current tech isn't fast enough, it's necessarily wrong. That doesn't sound like someone searching for the truth, but rather someone who won't admit that his current ideas (based on FAR inferior technology to AMM) are wrong. I guess one day when we get a 2000 or 5000 fps system we'll know the answer to Jeff's level of satisfaction, but the rest of us are trying to learn the best we can with the best tools we have. I guess in Jeff's world that makes us all irrational and wrongheaded, and I know we aren't going to change his mind, but I think his position is far less reasonable than those who are using the tech to try to figure out things the best they can."
Note that I have bold-highlighted certain statements, which I will now analyse. bph7 stated-: " If AMM was total garbage and just guessing, why do basically all tour pros exhibit many of the same characteristics?" First of all, I have no objection to the idea of a 3-D system operating at 240FPS being fully capable of measuring the rate of "left wrist extending" over a large distance (eg. P6 => impact). My problem is with his claim that all tour pros exhibit the same pattern of "left extending" between P6 and impact. For example, there is the first pattern (manifested by Dan Carraher's student golfer and Jordan Spieth) where the left wrist is about 23 degrees flexed at P6 and where the left wrist then extends rapidly to about 9 flexed at impact. However, there is a 2nd pattern described by Cheetham in his study of 94 pro golfers, where the left wrist increases its degree of flexion between P6 and near-impact and where the left wrist only starts to extend as it approaches impact. That 2nd pattern is very different to the 1st pattern, and I would like to better understand the biomechanics underlying this 2nd pattern and I would also like to know what percentage of tour golfers manifest this 2nd pattern. I also believe that there is a 3rd pattern seen in pro golfers (like Adam Scott and Henrik Stenson) who maintain an intact LAFW throughout their entire downswing and early followthrough, and I have not seen any 3-D graphs of that pattern. Why not? bph also stated-: " Jeff seems to think that since we can't get a certain fps, then the data is necessarily wrong." That claim is not true. I have only stated that one would need a 3-D system with a much higher FPS to accurately discover what is happening over the much shorter distance of P7 => P7.2 where the hands only move forward a few inches (as seen in Tim Burke's golf swing below). Note that Tim Burke's hands only move forward about 3-4" between P7 and P7.2 and I don't believe that a 3-D system operating at 240FPS can produce enough data points to accurately measure his rate of "left wrist extending" and rate of "left forearm supination" happening during the P7 (image 3) => P7.2 (image 4) time period. I also have expressed a theoretical objection to the possibility of there being a significant amount of "left wrist extending" and a significant amount of "left forearm supination" happening during that time period - based on the fact that the clubshaft is not bypassing the left arm (from an angular rotational perspective) and I strongly believe that my many Golf WRX critics are not addressing this issue in an intellectually scientific manner. Like bph7, I am also trying to learn the best I can with the best tools that golf researchers have available, and I only object to the rigid thinking of those GolfWRX forum members who believe that a 3-D system operating at 240FPS is the only valid tool and who totally reject 2-D images captured at 8,200 FPS ( without thoroughly explaining the deficiencies of any measurements obtained from those 2-D capture images). Jeff.
|
|
|
Post by imperfectgolfer on Jul 17, 2017 19:37:07 GMT -5
FWP wrote the following in post #265 of the GolfWRX thread-: " What is unreasonable is to think that you can begin to extend somewhere around to just after Club parallel, stop the extension at impact with a club traveling 115 mph and then begin extending again right after "p7.2475"I can understand why FWP thinks that is unreasonable, but I think that it is really happening in Tim Burke's golf swing where his clubhead speed is 150mph at impact. Here are DTL capture images. I think that even those 2-D capture images show that his left wrist is maximally flexed between P5.5 (image 1) and P6.2 (image 2) and that it's becoming less flexed by impact (see image 3 in the next series of face-on images). Now, I can understand why FWP may object to the possibility of the left wrist not extending significantly between impact (image 3) and P7.2 (image 4) on theoretical grounds, but I actually think that there is no significant "left wrist extending" (arbitrarily defined as >5 degrees) happening between P7 and P7.2. If FWP disagrees, then the burden-of-proof lies with him. He has to explain how it is possible to prevent the clubshaft from bypassing the left arm (from an angular rotational perspective) between P7 and P7.2 if the left wrist is extending >5 degrees during that time period. Finally, I suspect that Dan Carraher's student golfer can generate a clubhead speed of ~115mph and he was capable of extending the left wrist rapidly between P6 and P7, then "holding" the degree of left wrist flexion between P7 and P7.4 so that it only extended 2 degrees during that time period. So, that fact shows that it is readily possible. Jeff.
|
|