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Post by dubiousgolfer on Nov 10, 2018 6:26:51 GMT -5
Dr Mann I did ask Jon Sinclair about whether the data would be made public and also to confirm rotational stats of LPGA vs PGA . He sent me a reply as per below. "My data certainly shows the ladies rotations on average higher. Not just thorax but pelvis, arms and club. The easiest way I can put it is that it is easier to spin a smaller object than a bigger one. However that doesn’t mean that the outside edges of that smaller object will be moving faster than the larger one." I think the analogy he is trying to describe is similar to the spinning ice-skater whose arms/hands are initially pulled in but then suddenly stretched out. On first observation we think the whole rotation has slowed down (ie. we look at the body) , but in fact the hands are moving faster than when they are pulled in. Not sure how the above information can be used to explain why PGA golfers can still generate greater clubhead speed than LPGA but with slower angular velocities of thorax, pelvis, arms and club. My very tenuous possible explanation is below: If I just looked at the velocity of the clubs COG in the downswing , it should be: velocity = radius x angular acceleration If LPGA have greater angular acceleration, the PGA men must be swinging the club's COG on a larger radius that more than compensates for their inferior angular acceleration. That larger radius can be achieved in the early downswing when the club's COG is on a straighter path (an arc path with a large radius). Which suggest that the PGA men are retaining lag better than the LPGA women until CF induced release (even with slower angular velocities of thorax, pelvis, arms, club). The CF induced release will increase the angular velocity into impact with a greater clubhead speed than LPGA players. The problem here is whether that increased 'angular velocity' due to CF induced release must still be less than LPGA women? If yes, then the formula 'VELOCITY = RADIUS X ANGULAR ACCELERATION' must still apply at least into impact. So the radius of the club's COG into impact for PGA men must again more than compensate for their inferior angular acceleration (this doesn't seem a very likely scenario to me) I can only assume that they have taken an average of the 'pelvis /thorax/arms/club' rotation over the whole of the downswing. That PGA men will likely have superior clubhead COG angular velocity and CHS after CF induced release into impact. DG I am confused! Sinclair apparently claims that not only are LPGA female golfers generating a faster angular rotation of the pelvis and thorax, but he also claims that it also applies to the arms and clubshaft. If it applies to the clubshaft, then the primary rational explanation for the increased clubhead speed of male PGA golfers is presumably an increased swing radius (length of the left arm + clubshaft). Now, that assertion of increased swing radius may apply to some tall male golfers who are >6 feet tall, but many PGA tour golfers are relatively short eg. Jason Day. Also, Jamie Sadlowski is only 5'10" and he hits the ball >400 yards. I really would like to see Sinclair's data and I would also like to see him explain in detail why male PGA tour golfers drive the ball further than female LPGA golfers. Jeff. Dr Mann I have some graph/table data from Jon Sinclair (see below) but I am checking whether he made a typo error on his email , because the graph he said that applied for Men all have greater rotation values than the one he says are for Ladies. MEN LADIES If he has made a typo error and the bottom graph is for men rather than ladies , then look at the kinetic sequence of the arm rotation peaking before pelvis and thorax. The first graph imho does look more applicable to men and now wondering if someone at TPI has made an administrative error when they labelled these graphs. DG
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Post by dubiousgolfer on Nov 10, 2018 10:14:44 GMT -5
I now have confirmation from Jon Sinclair that there is NO typo error . This is what he said:
"The top one is the men. You have to look at the ranges not the players numbers. You will see the ladies bottom end slower than the men’s bottom end. The ladies top end faster then the men.
Like I said I gave the simplistic answer to your question. These are standard deviation calculations and I have a lot more men in the data base than women so the ladies have a wider range. I also believe that the ladies will naturally have a wider range anyway because their physical ability seems to range more.
A man’s numbers can be faster than a ladies. These are just averages. They can be deceiving. Comparing the two might be fun but it is apples and oranges to a degree. Be careful you don’t slip off down a rabbit hole. The goal is to efficiently transfer energy to the club head and it works the same way with men and women irregardless of the numbers you are looking at. As you can see in the two graphs the man does a much better job in this case. This is like looking at a kid vs adult. You are looking at two object where one is double the mass of the other. Their are anomalies in all data"
DG
PS. So these averages are statistically skewed because the sample size for the men far outweigh the women.
But if Jon Sinclair said "My data certainly shows the ladies rotations on average higher. Not just thorax but pelvis, arms and club." why don't the values on the graphs support that statement? Are these graphs showing average values over each group of LPGA and PGA players or are they derived from some other statistical formulae? Still finding the statements being made and values on the graphs contradictory.
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Post by imperfectgolfer on Nov 11, 2018 1:33:11 GMT -5
Here are copies of your attached graphs (so that guests can see the graphs).
Let's first analyse the graphs.
The male golfer's graph looks reasonable in the sense that it is compatible with a pivot-induced TGM swinger's action where the pivot induces the release of PA#4 and then PA#2 is subsequently released. I don't know if this particular 3D graph is supposed to represent the "average" male amateur golfer's 3D graph in Sinclair's collection of 3D graphs or a PGA tour pro golfer. I would be surprised to learn that this golfer is a pro golfer because the pelvis only starts to rotate in the later part of the early downswing (when the red graph crosses the zero line) and the green graph is above the red graph during the early downswing suggesting that the thorax is rotating before the pelvis, and that is a very sub-optimal kinematic sequence. The female golfer's 3D graph looks very sub-optimal. Note that the arm graph is above the pelvis/thorax graphs from the very start of the downswing and it peaks well before the peak of the pelvis/thorax graphs. That "fact" suggests that this female golfer is simply an arm swinger who uses the shoulder girdle muscles to power her golf swing and that the pivot motion is happening independently in a manner that is unrelated to the left arm motion, which is presumably powering her golf swing. Even stranger, is the fact that the clubhead speed graph is higher than the arm graph from the very start of the downswing. How is that possible? I can only imagine that this female golfer is casting and releasing PA#2 via a left wrist uncocking motion even before she starts to release PA#4. If this female golfer is actually casting and considering the additional fact that her arm speed reaches its peak speed well before the pelvis/thorax reach their peak speed, then I would not be surprised to discover that this female golfer is flipping well before impact. I would very much like to see a swing video of this female golfer's golf swing action. Now, let's consider the data provided. What do the range figures mean? Are they simply representative of other amateur male/female golfers in Sinclair's data set who are used for comparison purposes or do they represent pro golfers (PGA and LPGA golfers)? Note that the peak pelvic (715) and peak thorax speed (1092) of the fastest rotating female golfer is greater than the peak pelvic speed (540) and peak thorax speed (797) of the fastest male golfer. That does not surprise me because many females are so very flexible and lithe that they can rotate their pelvis and upper torso very fast. However, their pivot motion will not translate into increased clubhead speed if they are not using their pivot action to induce the release of PA#4 and if they simply releasing PA#4 with an arm-releasing action (ala Leslie King method) that is totally independent of their pivot action (as seen in that 3D graph). Also, note that the fastest female golfer can move her left arm at a peak speed of 1417 versus a peak speed of 1090 for the fastest male golfer. That is not surprising if the male golfer is using a pivot-induced released of the left arm while the female golfer is simply swinging the left arm independent of the pivot motion - because it is much easier to throw a frisbee faster with a backhanded throw where the left arm is abducted very fast away from the torso versus trying to use the pivot motion to catapult the left arm away from the rotating torso. However, that faster left arm motion will not result in a faster clubhead speed if that female golfer is casting and inefficiently releasing PA#2 (as seen in that female's 3D graph).
When you first mentioned that female LPGA golfers can rotate their pelvis and thorax faster than male PGA tour golfers, but couldn't generate faster clubhead speeds, I was surprised - because I wrongly presumed that they both used equally efficient pivot-induced TGM swinging actions and that they both released PA#2 with equal efficiency after maintaining the maximum degree of lag for the same time period. However, this female 3D graph suggests that the female golfers are not even using a pivot-induced release of PA#4 and that they are casting and very inefficiently releasing PA#2. Jeff.
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Post by dubiousgolfer on Nov 11, 2018 6:08:52 GMT -5
Dr Mann - Many thanks for this fantastic analysis. I mistakenly thought that both graphs represented some average over the total PGA and LPGA tested samples rather than individual golfer swing profile stats (which is why I thought Jon Sinclair's comments wasn't supported by the graphs).
DG
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Post by dubiousgolfer on Nov 12, 2018 9:38:47 GMT -5
I've received some other opinions from Dave Tutelman and a suggestion from Jon Sinclair: ------------------------------- Dave Tutelman: If women are really faster than men in angular velocity (the technical term for "rotational speed") in each of those categories -- INCLUDING CLUB -- then I can think of only two ways they can have slower clubhead speeds. (1) The peaks are at the wrong time. I'm inclined not to believe this one, but it's possible. (2) Lever arm length. Too many instructors believe that lever arm length by itself gives more clubhead speed. (linear velocity = angular velocity * lever arm length) But that's not necessarily true, and in fact often false. See my article on this at <http://tutelman.com/golf/swing/tallGolfer.php>. But in this case, we're talking about a stronger population in men. If they can stay close enough in angular velocities, then their larger size and longer clubs will give higher linear velocities. Jon Sinclair Maybe it will also help to know Dr Kwon has a calculation where he compares one person to another by adjusting for weight and size differences. This way you can see if one player to the other is generating the same energy pound for pound. -------------------- Both seem to imply that 'size/strength/longer lever arm' could account for the difference in driving distances but, as suggested before, there are many short PGA golfers who drive the ball longer than LPGA so lever arm length may not entirely explain the difference. If it's strength then where in the swing is this superior strength applied and how does it somehow get converted to clubhead speed? I know this is too simplistic, but when I look at the 'Trackman' averages for the angle of attack for the driver, the PGA have -1.3 degrees , while LPGA have +3.0 degrees. Obviously , I don't know what the average driver lofts are for PGA vs LPGA and what other club characteristics might affect AOA , but doesn't this imply that LPGA players are releasing earlier (non-optimal release of PA2#)? I could readily imagine the PGA players have more forward shaft bend happening than LPGA after release which would actually make their AOA less descending into impact. Doesn't the fact that PGA driver AOA is still more descending than LPGA 'tenuously' imply a later release? blog.trackmangolf.com/trackman-average-tour-stats/DG
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Post by imperfectgolfer on Nov 12, 2018 10:07:46 GMT -5
I've received some other opinions from Dave Tutelman and a suggestion from Jon Sinclair: ------------------------------- Dave Tutelman: If women are really faster than men in angular velocity (the technical term for "rotational speed") in each of those categories -- INCLUDING CLUB -- then I can think of only two ways they can have slower clubhead speeds. (1) The peaks are at the wrong time. I'm inclined not to believe this one, but it's possible. (2) Lever arm length. Too many instructors believe that lever arm length by itself gives more clubhead speed. (linear velocity = angular velocity * lever arm length) But that's not necessarily true, and in fact often false. See my article on this at <http://tutelman.com/golf/swing/tallGolfer.php>. But in this case, we're talking about a stronger population in men. If they can stay close enough in angular velocities, then their larger size and longer clubs will give higher linear velocities. Jon Sinclair Maybe it will also help to know Dr Kwon has a calculation where he compares one person to another by adjusting for weight and size differences. This way you can see if one player to the other is generating the same energy pound for pound. -------------------- Both seem to imply that 'size/strength/longer lever arm' could account for the difference in driving distances but, as suggested before, there are many short PGA golfers who drive the ball longer than LPGA so lever arm length may not entirely explain the difference. If it's strength then where in the swing is this superior strength applied and how does it somehow get converted to clubhead speed? I know this is too simplistic, but when I look at the 'Trackman' averages for the angle of attack for the driver, the PGA have -1.3 degrees , while LPGA have +3.0 degrees. Obviously , I don't know what the average driver lofts are for PGA vs LPGA and what other club characteristics might affect AOA , but doesn't this imply that LPGA players are releasing earlier (non-optimal release of PA2#)? I could readily imagine the PGA players have more forward shaft bend happening than LPGA after release which would actually make their AOA less descending into impact. Doesn't the fact that PGA driver AOA is still more descending than LPGA 'tenuously' imply a later release? blog.trackmangolf.com/trackman-average-tour-stats/DG Unlike David Tutelman, I am not presently willing to accept that the fastest male PGA golfers are generating lower clubshaft angular velocities than the fastest female LPGA golfers. If that were true, than the only rational explanation for the greater clubhead speeds of the male pro golfers would be lever length. It is very difficult for me to believe that lever length is the major factor responsible for the fact that the fastest male pro golfers can drive farther than the fastest female pro golfers. There is a you-tube video of Jamie Sadlowski driving the ball ~350 yards using a 29" long driver. By the way, I have been studying some LPGA golfers' and female long-drive competitors' golf swings, and they look to have the standard kinematic sequence and they seem to be using a pivot-induced release of PA#4 without casting. I wonder whether that female 3D graph by Sinclair is an outlier, rather than being typical. What did David Tutelman have to say about that graph? Note that the slope of the clubhead speed graph in the 2nd half of the downswing is much steeper in the male golfer compared to the female golfer and I presume that it is secondary to a more efficient release of PA#2. What does David Tutelman think? Dr. Kwon making adjustments for height and weight is non-scientific because it presumes that the "swing efficiency" factor is otherwise the same for all golfers. I don't think that a more negative AoA measured at impact implies a later release of PA#2 because you have to consider ball position. Many male long-drive competitors have a positive AoA at impact because they place the ball further forward. Jeff.
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Post by dubiousgolfer on Nov 12, 2018 21:07:39 GMT -5
Dr Mann - Jon Sinclair has confirmed that the graphs were for 2 individuals. Dave Tutelman didn't comment on the graphs .
It's a pity we can't see this type of graph for an LPGA player with one of the higher peak 'club angular velocities' but with an added graph line showing clubhead speed.
Could the Ryke effect explain this anomaly? Kevin Ryan mentioned the following in his you-tube video at 11:15 where he says " If professionals have large Ryke angles then can achieve significant clubhead speeds with relatively low angular velocities of their lead arm".
I wonder if 3D systems measure 'clubhead conical angular velocities around the lead arm' or 'clubhead angular velocity longitudinally around the wrists' (as per Kevin Ryan - but uncertain what he meant by longitudinally).
DG
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Post by imperfectgolfer on Nov 12, 2018 23:40:29 GMT -5
Dr Mann - Jon Sinclair has confirmed that the graphs were for 2 individuals. Dave Tutelman didn't comment on the graphs . It's a pity we can't see this type of graph for an LPGA player with one of the higher peak 'club angular velocities' but with an added graph line showing clubhead speed. Could the Ryke effect explain this anomaly? Kevin Ryan mentioned the following in his you-tube video at 11:15 where he says " If professionals have large Ryke angles then can achieve significant clubhead speeds with relatively low angular velocities of their lead arm". I wonder if 3D systems measure 'clubhead conical angular velocities around the lead arm' or 'clubhead angular velocity longitudinally around the wrists' (as per Kevin Ryan - but uncertain what he meant by longitudinally). DG Consider this Kevin Ryan quote-: " If professionals have large Ryke angles then can achieve significant clubhead speeds with relatively low angular velocities of their lead arm". It is true that if a golfer has a large accumulator #3 angle at impact (like Sergio Garcia) - due to the fact that he shallows his clubshaft a lot between P4 and P5.5 - that his clubhead path is going to be more conically pendular between P5.5 and impact. That means that when PA#2 releases it causes the clubhead to more slowly catch up to the left arm because the clubhead is traveling along a wider arc. However, it is also true that the left arm will be moving slower in a targetwards direction during that time period so there is more time-opportunity for the clubhead to catch up to the left arm by impact, so the two phenomenona may cancel each other out and I cannot envisage why it would increase clubhead speed at impact from a linear perspective. However, I do agree that it will increase the clubhead speed relative to the angular speed of left arm motion in a targetwards direction - because the left arm has to travel slower if the clubhead path is conically pendular. I have noted that most long-drive competitors do not shallow the clubshaft during their early-mid downswing and they have a small accumulator #3 angle at impact. Here is Jamie Sadlowksi's swing action.
The red splined path is his hand arc path. Note that he does not shallow his clubshaft between P4 and P5.5 which means that his clubhead path will not be conically pendular between P5.5 and impact. Note that his clubhead path between P5.5 and impact is not conically pendular and that he has a small accumulator #3 angle at impact. He also uses a very strong left hand grip, which means that he doesn't have to use a PA#3 release action between P5.5 and impact and that means that his clubshaft can very quickly catch up to his left arm by impact if he releases PA#2 very efficiently even though his left arm does not slow down between P5.5 and impact as much as Sergio Garcia's left arm (who has a very large accumulator #3 angle at impact). My "best guess" is that Jamie Sadlowski's swing action is much better for generating a higher clubhead speed at impact than Sergio Garcia's swing action.
Jeff.
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Post by dubiousgolfer on Nov 13, 2018 18:11:48 GMT -5
So Jamie Sadlowski doesn't need to induce any Ryke effect because biomechanically (due to his amazing flexibility) he seems able to create CHS while still avoiding those 'mechanical joint singularity conditions' that Kevin Ryke mentioned in his video? Can we also assume that there are many PGA/LPGA golfers who are more able to create CHS without the need to use Ryke effect and can square the clubface using PA3# ? But can we also assume that there many PGA/LPGA players that might be utilising the Ryke effect and that PGA players might be able to do so more efficiently than LPGA players?
If I've interpreted Kevin Ryan correctly , the gradual pitching action of the lead arm will cause an increasing 'tension' in the clubshaft , while also allowing the initial 'DP-Double Pendulum inertia' of the clubhead to create a torque around the lead arm axis. That the 'tension' will keep increasing by the lead arm pitching action until the vertical upwards component of that tension cancels the clubhead DP motion and converts it completely to a conical pendulum path.
The formula for the clubhead conical angular velocity (around the lead arm axis) is W= √[g/lcos(x)] g = acceleration due to gravity, l is length of clubshaft, x is the angle between clubshaft and lead arm (PA3 angle?)
g and l are constants so the only way to increase W is by increasing angle 'x' which will make cos(x) a smaller value . To increase 'x' I am assuming one will need to 'pitch' that left arm more which will increase the tension in the clubshaft (and that increased tension will be used to transfer energy to the clubhead).
Can we assume that many PGA players (excluding those that don't invoke the Ryke effect) will be more adept in creating that pitching left arm action and increased clubshaft tension than LPGA players? That by inducing the Ryke effect earlier , they will therefore negate the DP motion earlier, which will mean less lead arm angular rotation speed in the DP plane into impact, less clubshaft angular rotation speed around the wrists (PA2 angle) into impact , but increased conical angular velocity W (around the lead arm) and therefore CHS into impact.
Could the above tenuously explain the TPI stats where generally PGA players (not all) are showing less angular rotation speeds (in the DP plane) for 'lead arm/club' than LPGA while still having larger clubhead speeds due to superior W ?
I'm unsure whether 3D systems would be able to currently measure 'W' or operate in any frequency to see enough data points on a graph to be of any use.
DG
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Post by imperfectgolfer on Nov 14, 2018 0:47:37 GMT -5
So Jamie Sadlowski doesn't need to induce any Ryke effect because biomechanically (due to his amazing flexibility) he seems able to create CHS while still avoiding those 'mechanical joint singularity conditions' that Kevin Ryke mentioned in his video? Can we also assume that there are many PGA/LPGA golfers who are more able to create CHS without the need to use Ryke effect and can square the clubface using PA3# ? But can we also assume that there many PGA/LPGA players that might be utilising the Ryke effect and that PGA players might be able to do so more efficiently than LPGA players? If I've interpreted Kevin Ryan correctly , the gradual pitching action of the lead arm will cause an increasing 'tension' in the clubshaft , while also allowing the initial 'DP-Double Pendulum inertia' of the clubhead to create a torque around the lead arm axis. That the 'tension' will keep increasing by the lead arm pitching action until the vertical upwards component of that tension cancels the clubhead DP motion and converts it completely to a conical pendulum path. The formula for the clubhead conical angular velocity (around the lead arm axis) is W= √[g/lcos(x)] g = acceleration due to gravity, l is length of clubshaft, x is the angle between clubshaft and lead arm (PA3 angle?) g and l are constants so the only way to increase W is by increasing angle 'x' which will make cos(x) a smaller value . To increase 'x' I am assuming one will need to 'pitch' that left arm more which will increase the tension in the clubshaft (and that increased tension will be used to transfer energy to the clubhead). Can we assume that many PGA players (excluding those that don't invoke the Ryke effect) will be more adept in creating that pitching left arm action and increased clubshaft tension than LPGA players? That by inducing the Ryke effect earlier , they will therefore negate the DP motion earlier, which will mean less lead arm angular rotation speed in the DP plane into impact, less clubshaft angular rotation speed around the wrists (PA2 angle) into impact , but increased conical angular velocity W (around the lead arm) and therefore CHS into impact. Could the above tenuously explain the TPI stats where generally PGA players (not all) are showing less angular rotation speeds (in the DP plane) for 'lead arm/club' than LPGA while still having larger clubhead speeds due to superior W ? I'm unsure whether 3D systems would be able to currently measure 'W' or operate in any frequency to see enough data points on a graph to be of any use. DG You wrote-: "Sadlowski doesn't need to induce any Ryke effect because biomechanically (due to his amazing flexibility) he seems able to create CHS while still avoiding those 'mechanical joint singularity conditions' that Kevin Ryke mentioned in his video? Can we also assume that there are many PGA/LPGA golfers who are more able to create CHS without the need to use Ryke effect and can square the clubface using PA3#".
I don't know what you mean by the term "mechanical joint singularity conditions". I believe that any golfer who does not shallow the clubshaft in the downswing and comes into impact with a small accumulator #3 angle will not be using the RYKE effect. Sadlowski does not shallow his clubshaft and he can simply release PA#4 => PA#2 without having to think about using the RYKE effect because he doesn't need to perform a PA#3 release action in his later downswing because he uses a very strong left hand grip. By constrast, Phil Mickelson uses a neutral left hand grip and he therefore needs to perform a PA#3 release action - and he would benefit by the RYKE effect, which can provide a passive force that will supinate the lead forearm. However, he cannot use the RYKE effect because his comes down the TSP without any clubshaft shallowing.
Image 1 is address, image 2 is at his end-backswing (P4) position, image 3 is at his P5 position, image 4 is at his P5.5 position and image 5 is impact.
I have drawn a red line along Phil Mickelson's clubshaft at address, and that represents his hand plane. I have drawn a blue line between the ball and his rear elbow at address and that line represents his elbow plane. I have drawn a yellow line between the ball and his rear shoulder socket when he is at his end-backswing position, and that line represents the turned shoulder plane (TSP). Note that there is very little difference in the degree of steepness of his elbow plane relative to his TSP.
Note that his lead arm is near-vertical at address and that an extension of the hand plane line drawn out from the butt end of the club points at his belt buckle.
Note that Phil Mickelson's lead hand and clubshaft are on the TSP at his end-backswing postion (image 2).
Note that Phil Mickelson only shallows his clubshaft by a very small (and negligible) amount between P4 and P5 (image 3) as his clubshaft shallows down to the blue line which is not significantly shallower than the yellow line.
Note that his clubshaft is still on the blue elbow plane line at P5.5 (image 4) and at impact (image 5). Note that Phil Mickelson basically does not shallow his clubshaft during his downswing action - note that his clubshaft is minimally shallower than the yellow TSP line at impact. Note how outstretched his lead arm is impact and how his clubshaft is nearly straight-line-aligned with his lead arm at impact because he has a small accumulator #3 angle.
So, how does Phil Mickelson perform a PA#3 release action without having the benefit of the RYKE effect phenomenon? Here is the answer. Image 1 is just bypassed the P6 position. Note that his clubface is still open to the clubhead arc and that the toe of his clubhead is pointing up (skywards) and that it is also tilted slightly backwards away from the ball-target line. Note that the clubface is parallel to the back of his lead hand and watchface area of his lead lower forearm because he has maintained an intact LFFW. Note that the back of his lead hand, and watchface area of his lead lower forearm, is parallel to the inclined plane, which has a degree of steepness roughly equivalent to the steepness of the TSP because he did not shallow his clubshaft during his early-mid downswing.
Image 2 is at the P6.7 position. Note that the clubface is still wide open relative to the ball-target line and also relative to the clubhead arc. Note that the back of his lead hand, and watchface area of his lead lower forearm, is still roughly parallel to the inclined plane, which has roughly the same degree of steepness as the TSP because he is not shallowing his clubshaft between P6 and P6.7. Note that there is no evidence that Phil Mickelson is significantly supinating his lead forearm between P6 and P6.7. Note that he has significantly released PA#2 (in the plane of his intact LAFW) between P6 and P6.7 and that the clubshaft has nearly caught up to his lead arm by P6.7.
Image 3 is at impact, where he has squared his clubface by supinating his lead forearm by the amount needed to acquire a square clubface by impact. In other words, Phil Mickelson delays his PA#3 release action and he only significantly supinates his lead forearm between P6.7 and impact. If virtually all of his lead forearm supinatory motion happens in that short pre-impact time period between P6.7 and impact, that means that the amount of clubface roll per unit degree of clubhead travel is very large as his clubhead travels along the last 18" of his clubhead travel path just before impact. That large amount of ROC (rate-of-closure) of his clubface in the last 18" of clubhead travel along the clubhead arc (just before impact) is potentially a great disadvantage because it makes it much more difficult for him to time his clubface roll so that the clubface can be guaranteed to be square at impact. What aggravates the timing of his clubface-squaring phenomenon is the fact that Phil Mickelson needs to use an active muscular force to perform his PA#3 release action's left forearm supinatory motion. Why can Phil Mickelson not use passive forces to square his clubface by impact? First of all, Phil Mickelson cannot use the passive "torque force" (described by Sasho MacKenzie) because he does not shallow his clubshaft during his early-mid downswing. Secondly, he cannot use the passive RYKE phenomenon (described by Kevin Ryan) because he has too small an accumulator #3 angle between P6.7 and impact. So, he is dependent on using an active muscle force derived from an active muscular contraction of his lead forearm's supinator muscles (+/- his rear forearm's pronator muscles if they are used synergistically to assist in the clubface-squaring phenomenon). The amount of active muscular force required is very small because the *moment-of-inertia is very small - and that is because the clubshaft has nearly caught up to his straight lead forearm by P6.7.
Golfers (eg. Sergio Garcia) who shallow the clubshaft by a large amount between P4 and P5.5 come into impact with a vertical left arm (and not an outstretched left arm) and a large accumulator #3 angle. They can use the RYKE effect to help them decrease the amount of active left forearm supinatory muscular force needed to release PA#3. Here is Sergio Garcia's late downswing action.
Image 1 is at the P5.5 position. Note that Sergio Garcia has already shallowed his clubshaft down to his desired impact plane - the hand plane.
Note that his clubface is wide open relative to his clubhead arc - but that his clubface is straight-line-aligned relative to the back of his left hand, and the watchface area of his left lower forearm, because he has an intact LFFW.
Image 2 is at the P6 position. Note that the back of his left hand, and watchface area of his left lower forearm, is more vertically oriented and that means that he has rotated his left forearm counterclockwise by a significant amount between P5.5 and P6. What makes it biomechanically easier for him to rotate his intact LFFW so much counterclockwise between P5.5 and P6, when he still has a large moment-of-inertia (due to the fact that he still has large amount of clubhead lag present), is the "fact" that he can utilise the passive "torque force" (described by Sasho MacKenzie) that is secondary to the fact that his clubshaft's plane of motion is below his hand arc path's plane of motion. Note how much he has squared his clubface relative to his clubhead arc by P6 due to his early left forearm supination phenomenon.
Image 3 is at P6.5. Note that he is continuously, and progressively, supinating his left forearm between P6 and P6.5, and that his clubface is becoming progressively more square to his clubhead arc.
Image 4 is at impact where he presumably has a square clubface.
During the P6 => P7 time period, his clubshaft is tracing a conical pendular path and it is probably under the beneficial influence of the passive RYKE effect phenomenon because he has a large accumulator #3 angle (which is exactly equivalent in magnitude to the RYKE angle). That means that he doesn't have to use much left forearm supinatory muscular force during his PA#3 release action - because so many beneficial passive clubface-squaring forces are operant. Most importantly, note that the amount of clubface roll happening per unit amount of clubhead travel during his late downswing between P6.7 and impact is very small because his clubface rolling action (due to left forearm supination) happens very gradually, and very steadily, over a much longer time period of clubhead travel between P5.5 and impact - and that is potentially of great benefit to Sergio Garcia when it comes to consistently timing his late downswing's clubface-squaring action (compared to Phil Mickelson's delayed clubface-squaring action that happens very fast between P6.7 and impact).
In summary, shallowing the clubshaft between P4 and P5.5 and coming into impact with a vertical left arm and a large accumulator #3 angle is beneficial in terms of more easily squaring the clubface - but I cannot see how it can contribute to generating a lot of clubhead speed. Therefore, I cannot understand your hypothesis when you ask-: "Could the above tenuously explain the TPI stats where generally PGA players (not all) are showing less angular rotation speeds (in the DP plane) for 'lead arm/club' than LPGA while still having larger clubhead speeds due to superior W ? I cannot understand your mathematical argument (because I struggle understanding arguments based on physics/mathematics), and I cannot understand why having a larger accumulator #3 angle can possibly increase linear clubhead speed (although I can understand how it can increase clubhead speed relative to the left arm's angular speed). I also do not think that the "average" PGA golfer has a larger accumulator #3 angle than the "average LPGA golfer. Why should they?
Jeff.
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Post by dubiousgolfer on Nov 14, 2018 6:16:16 GMT -5
Many thanks Dr Mann for that detailed explanation.
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Post by dubiousgolfer on Nov 16, 2018 8:50:01 GMT -5
Dr Mann
I have been unable to work out the maths/physics involved that would increase the 'linear velocity' of the clubhead from DP to conical motion just using the Ryke effect (so I've asked Kevin Ryan to provide the proof).
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Post by imperfectgolfer on Nov 16, 2018 10:09:32 GMT -5
Dr Mann I have been unable to work out the maths/physics involved that would increase the 'linear velocity' of the clubhead from DP to conical motion just using the Ryke effect (so I've asked Kevin Ryan to provide the proof). I would very much like to know how a conical pendular motion can possibly increase linear clubhead speed at impact - compared to a single-plane double pendular motion where the clubshaft does not have to rotate around its longitudinal axis during the release (as seen in Jamie Sadlowski's golf swing action where he only releases PA#4 => PA#2 and where there is no clubshaft shallowing to a shallower plane in the late downswing and where he doesn't have to rotate the clubshaft around its longitudinal axis due to his very strong left hand grip). Jeff.
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Post by dubiousgolfer on Nov 18, 2018 19:20:00 GMT -5
Dr Mann Have you ever read this article (quite old back in 2008)? www.researchgate.net/publication/5292347_Swing_Kinematics_for_Male_and_Female_Pro_GolfersIt does seem to imply small differences between the kinematics of PGA vs LPGA except in the maximum angular velocities of the uncocking of the wrists and the timing of the maximisation of those velocities in the downswing. Not sure what they mean by "Significant lower wrist angular velocity for the LPGA group may indicate greater locking and breaking of the wrist, which may be related to a higher incidence of injury of the wrist seen in the LPGA players." Apparently there were twice as many wrist injury incidents for LPGA vs PGA but what do they mean by 'locking and breaking'? Are they suggesting that there is some physical limitation on how quickly LPGA players wrists can uncock their wrists? There also seems to be a significant difference in the max angular velocity of right arm extension. So doesn't this study suggest that differences in clubhead speed might be due to physical limitations between males and females to efficiently release PA2 and PA1? DG
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Post by imperfectgolfer on Nov 18, 2018 23:28:57 GMT -5
Dr Mann Have you ever read this article (quite old back in 2008)? www.researchgate.net/publication/5292347_Swing_Kinematics_for_Male_and_Female_Pro_GolfersIt does seem to imply small differences between the kinematics of PGA vs LPGA except in the maximum angular velocities of the uncocking of the wrists and the timing of the maximisation of those velocities in the downswing. Not sure what they mean by "Significant lower wrist angular velocity for the LPGA group may indicate greater locking and breaking of the wrist, which may be related to a higher incidence of injury of the wrist seen in the LPGA players." Apparently there were twice as many wrist injury incidents for LPGA vs PGA but what do they mean by 'locking and breaking'? Are they suggesting that there is some physical limitation on how quickly LPGA players wrists can uncock their wrists? There also seems to be a significant difference in the max angular velocity of right arm extension. So doesn't this study suggest that differences in clubhead speed might be due to physical limitations between males and females to efficiently release PA2 and PA1? DG DB, You deserve plaudits for your persistence in researching and studying this topic. This paper is new to me, and it is much more credible and useful than Sinclair's 3D-data. Sinclair's 3D graph for that female LPGA golfer showed casting and a premature left arm release motion that was not pivot-driven, but when I started to examine some swing videos of LGPA golfers they seemed to have the same kinematic sequence as men and they both use a pivot-driven TGM swinging action. This research paper seems to confirm that LPGA golfers swing in a similar manner to PGA golfers with only slight differences. Females have slightly faster pelvic rotation speeds while men have slightly faster trunk rotation speeds (in contrast to Sinclair's claim that LPGA golfers rotated both their pelvis and trunk faster than PGA golfers). The biggest difference seems to be left wrist uncocking speeds with men being significantly faster than women. Their peak left wrist uncocking speed also happens slightly later in the downswing. That suggests that men may be releasing PA#2 later and with more efficiency. Men also reach their maximum linear clubhead speed later than women, which would correlate with a later release of PA#2 that also results in a faster PA#2 release. Women may be releasing PA#2 earlier and they then reach their peak clubhead speeds slightly earlier in the late downswing because of an earlier and less efficient release of PA#2. Although their maximum clubhead speed is only 2m/second slower than men, it happens slightly earlier in their late downswing possibly due to an earlier and less efficient release of PA#2 and their linear clubhead speed may then slow down more before impact (accounting for a less far driving distance). I wonder why they didn't publish their maximum clubhead speeds at the time of impact. Unforunately, they also did not measure the maximum degree of lag and when the club (PA#2) first starts to release, which could confirm my suspicions that male golfers may be retaining more lag at P5.5/P6 and that they then release PA#2 faster. They also did not measure right elbow angles at P4, P5, and then again at P5.5/P6 to see if the men retained more right elbow bend for longer, which would correlate with a greater ability to hold lag for longer during the mid-downswing. The speed of right elbow release (right elbow extension) is not relevant because it depends on the position of the right elbow at the time of right elbow straightening and I don't think that any right elbow straightening action is active in either men PGA golfers or women LPGA golfers (as that would imply an active release of PA#1 which theoretically should not happen in a TGM swinging action). The relative speed of right wrist straightening in men versus women is also irrelevant because it depends on whether the golfer "runs-out-of-right arm" and we do not know the position of the right shoulder, or the right elbow, when these golfers release PA#2 and we also do not know whether they have a "running-out-of-right arm" problem in their later downswing. I don't think that the small differences in X-factor are significant in terms of the swing speed differences between men and women. I do not know what he means by the terms left wrist locking or breaking. He may equate "locking" with deliberately holding lag for longer and "breaking" with the release of PA#2. However, and alternatively, he may be referring to left wrist extension when using the term left wrist "breaking", but that phenomenon should not happen if a golfer maintains a GFLW/intact LFFW throughout the entire downswing. It is a pity that golf researchers are so TGM-illiterate. They could potentially design their research studies much better if they better understood TGM mechanics. In particular, I would have liked to see a measurement comparison between men and women of i) their speed of release of PA#4 between P4 and P5.5, ii) their degree of lag at P5.5, iii) their speed of release of PA#2 and iv) their accumulator #3 angles at impact. Jeff.
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