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Post by imperfectgolfer on Nov 21, 2012 10:15:35 GMT -5
See this BM-forum thread. www.brianmanzella.com/golfing-discussions/17825-what-kind-release-w-page-18-pic-21.htmlBM is attempting to prove that the hips decelerate pre-impact, and he is posting these photos from Taylormade. Although I agree that the pelvic rotation reaches maximum speed at the end of the early downswing, I think that these measurements don't reflect reality. Note that the pelvis rotation is measured as if the left-and-right pelvis rotate at the same speed. I think that it doesn't apply to many pro golfers who use a left hip clearing action to start the downswing - where the left buttocks gets pulled back to the tush line much faster than the right pelvis leaves the tush line. Consider Phil Mickelson. I have drawn a red line against the back of his rear (left) buttocks when Phil Mickelson (a lefty) is at his end-backswing position (image 1) and that red line represents the tush line. Image 2 shows his early downswing pelvic action - note how much he has pulled his lead (right) pelvis back towards the tush line while still keeping his rear (left) buttocks against the tush line. Image 3 shows him in his mid-downswing and one can see that his rear buttocks has pulled slightly away from the tush line, while his lead buttocks is now abutting against the tush line. Image 4 shows him at impact with an open pelvis and with his lead buttocks against the tush line. In golfers like Phil, how are the researchers measuring pelvic rotation? Are they placing their pelvic markers on one side or both sides of the pelvis? Also, note that they are measuring mid-torso rotation. However, that doesn't reflect shoulder rotation speed. Also, the right shoulder moves on a different axis than the left shoulder as the downswing evolves. Finally, that golfer is stalling his pelvis through impact (like Dustin Johnson) and he is using a CF-arm release action. That model doesn't reflect Ben Hogan's swing - who used a continuous pelvic motion and a CP-arm release action. Jeff.
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Post by tomdavis76 on Nov 21, 2012 23:54:12 GMT -5
Don't overlook that all three MATT golfers Manzella posted ACCELERATE the shoulders into impact, blowing the beloved "distal-to-proximal" theory to smithereens.
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Post by imperfectgolfer on Nov 22, 2012 0:40:42 GMT -5
Jeffy, Could you please supply data that shows that golfers accelerate their shoulders into impact? Those BM-supplied torso values seen in those photos relate to the mid-torso and not the shoulders. I am also skeptical of their accuracy-of-measurment. All the research articles that I have read indicate that shoulder rotation speed is maximum in the mid-downswing. Here is an example. The table comes the Myers paper. The Role of Upper Torso and Pelvis Rotation in Driving Performance in the Golf Swing. Joseph Myers, Scott Lephart, Yung-Shen Tsai, Timothy Sell, James Smoliga, and John Jolly. Journal of Sports Sciences, January 15th 2008; 26(2): 181 – 188. Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, NC, USA. Abstract: While the role of the upper torso and pelvis in driving performance is anecdotally appreciated by golf instructors, their actual biomechanical role is unclear. The aims of this study were to describe upper torso and pelvis rotation and velocity during the golf swing and determine their role in ball velocity. One hundred recreational golfers underwent a biomechanical golf swing analysis using their own driver. Upper torso and pelvic rotation and velocity, and torso-pelvic separation and velocity, were measured for each swing. Ball velocity was assessed with a golf launch monitor. Group differences (groups based on ball velocity) and moderate relationships (r >/= 0.50; P < 0.001) were observed between an increase in ball velocity and the following variables: increased torso - pelvic separation at the top of the swing, maximum torso - pelvic separation, maximum upper torso rotation velocity, upper torso rotational velocity at lead arm parallel and last 40 ms before impact, maximum torso - pelvic separation velocity and torso - pelvic separation velocity at both lead arm parallel and at the last 40 ms before impact. Torso - pelvic separation contributes to greater upper torso rotation velocity and torso - pelvic separation velocity during the downswing, ultimately contributing to greater ball velocity. Golf instructors can consider increasing ball velocity by maximizing separation between the upper torso and pelvis at the top of and initiation of the downswing. PMID: 17852693 [PubMed - as supplied by publisher. What's the "distal to proximal" theory? Jeff.
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Post by imperfectgolfer on Nov 22, 2012 11:16:53 GMT -5
See Jeffy post #14 in his thread. jeffygolf.com/showthread.php?517-Brian-Manzella-PictureHe refers to a peak mid-torso speed that peaks occurs well after impact. So, what does that have to do with power generation and clubhead speed? How does a progressive increase in mid-torso rotation through impact (from P7 to P8) increase clubhead speed? I think that any fast torso rotation after impact is secondary to the gained momentum of the club/arms pulling the torso around to a finish if the golfer attempts to keep the arms/club in front of the rotating torso and the gained momentum of the club/arms after impact reflect power generation phenomena that occur pre-impact. Golfers who use a CP-arm release action will rotate their mid-upper torso much faster after impact than golfers who use a CF-arm release action - even if they have the same clubhead speed at impact. Although I don't believe in the kinetic link theory, I do believe in the kinematic sequence theory - as exemplified by this TPI graph, which shows that upper torso rotation speed peaks well before impact. Note the difference between the timing of the peak of thorax rotational speed in amateur 2 versus the pro golfer. Jeff.
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Post by tomdavis76 on Nov 22, 2012 16:41:05 GMT -5
Re: the Myers paper, key part of the study:
One hundred recreational golfers underwent a biomechanical golf swing analysis using their own driver.
Not interested.
Distal-to-proximal is the same as the kinetic sequence theory.
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Post by tomdavis76 on Nov 22, 2012 16:44:22 GMT -5
See Jeffy post #14 in his thread. jeffygolf.com/showthread.php?517-Brian-Manzella-PictureHe refers to a peak mid-torso speed that peaks occurs well after impact. So, what does that have to do with power generation and clubhead speed? How does a progressive increase in mid-torso rotation through impact (from P7 to P8) increase clubhead speed? I think that any fast torso rotation after impact is secondary to the gained momentum of the club/arms pulling the torso around to a finish if the golfer attempts to keep the arms/club in front of the rotating torso and the gained momentum of the club/arms after impact reflect power generation phenomena that occur pre-impact. Golfers who use a CP-arm release action will rotate their mid-upper torso much faster after impact than golfers who use a CF-arm release action - even if they have the same clubhead speed at impact. Although I don't believe in the kinetic link theory, I do believe in the kinematic sequence theory - as exemplified by this TPI graph, which shows that upper torso rotation speed peaks well before impact. Note the difference between the timing of the peak of thorax rotational speed in amateur 2 versus the pro golfer. Jeff. TPI is reporting data that is markedly different from MATT. Who should we believe?
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Post by imperfectgolfer on Nov 22, 2012 17:34:13 GMT -5
I don't believe in either the MATT or TPI results. I believe in what is visually-apparent when viewing SwingVision videos recorded at ~4,000 frames/second. Consider this DJ swing as presented by MATT. The arm rotational speed is faster at the start of the downswing than torso and pelvic rotation speed. That is incompatible with the TPI graphs, where the arms never travel faster than the torso prior to the release of PA#4. My explanation is that the MATT and TPI system don't measure arm speed in the same way. Consider DJ's early downswing. Image 1 shows his end-backswing position - note his high left arm. Note how he drops his hands down in his early downswing (images 2 and 3) by a very active adduction of the right upper arm - while maintaining a a fully loaded PA#4. The TPI system probably doesn't measure this left arm motion (which is dropping in a vertical plane) because the left arm is not moving away from the chest wall - as occurs when PA#4 eventually unloads. I suspect that the MATT system is measuring this vertical motion - which has nothing to do with the release of PA#4, but is merely due to a repositioning of the power package in the early downswing (image 2's left arm/club alignment is similar to how a golfer like Hunter Mahan's left arm/club alignment looks like at the end-backswing position). Look at the MATT graph showing that DJ's torso rotation is not increasing markedly post-impact - as shown in this other tour player's MATT graph. Why? It is not surprising when one actually studies DJ's slow-mo video using a swing analyser program. Here is DJ's post-impact arm release action. Note how he uses a CF-arm release action. That doesn't require much torso rotation post-impact. Also, his pelvis and shoulders are already very open at impact and he doesn't have to rotate his pelvis after impact - as occurs in a golfer like Hunter Mahan who uses a CP-arm release action. Here is Hunter Mahan's swing - note his marked degree of torso/arm rotation between impact and the P8+ position, and his CP-arm release action. I can easily predict that his MATT torso/arm rotational graph measurements after impact are going to be very different than DJ's. I cannot fathom why BM believes that a 3-D system is providing more accurate/useful data than video (taken from multiple angles) recorded at 4,000 frames/second. BM believes that the left wrist doesn't remain flat immediately after impact- based on MATT measurements. I believe that he is wrong-headed as this John Oda video (recorded at 8,200 frames/sec) clearly demonstrates. Jeff.
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Post by imperfectgolfer on Nov 23, 2012 0:51:26 GMT -5
I think that BM is getting progressively more hysterically idiotic. Here is a statement that he made in his BM-forum thread. "I n my view, it is the application of the correct forces and torques through the ball that cause the decelerations." That wild statement has no explanatory content. I will happily donate $100 to any forum member (including Natep) if he can rationally explain that cause-and-effect claim. I will also donate a $100 to any person who can explain the following BM claims. 1. The fact that you should be in negative alpha. negative beta, and positive gamma through impact, can only be really performed correctly with a BIG assist from the arms, torso, and pelvis. What is the nature of the BIG assist? 2. Mike Jacobs can tell you of golfers trying to "have the club up their left way past impact" with very NON-tour like velocities measured on 3D, who SUDDENLY, in the course of a swing or two, having much better velocities just by applying the correct idea to the left and right wrist movements.What is the correct idea regarding the left and right wrist movement? How does that correct idea ensure a square clubface through impact? Does David Toms have the correct idea re: left and right wrist movements through impact in this next sequence? Jeff.
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Post by imperfectgolfer on Nov 23, 2012 9:43:25 GMT -5
I think that different pro golfers have very different pelvic motions and I cannot understand why one would try and map their pelvic motions using a MATT or TPI system. Consider Bubba Watson's downswing action. He initiates his downswing with a very assertive pelvic rotation. Note that he starts the downswing with a pelvic rotation movement - image 1. Note how he has an extraordinary amount of torso-pelvic separation and that he keeps his shoulders back at the start of the downswing - image 2. Note that he only starts to rotate his upper torso in image 3. Consider his later downswing. Here are capture images. Image 2 shows BW at the P5.5 position - note that his pelvis is already open and his shoulders closed (due to a large amount of torso-pelvic separation). I have drawn a red line across his posterior pelvic crest. Image 1 shows Phil Mickelson at the P5.5 position - note his shoulders are equally closed, but his pelvis is square and not as open as BW's pelvis. Image 3 shows BW at impact. Note that his pelvis is elevated (blue line) due to the fact that he has straightened both knees and also got onto his toes, and that it causes his pelvic motion to stall (decelerate). Image 4 shows BW at the P8 position - note that his pelvic motion has stalled and there is minimal further pelvic rotation between P7 and P8. That is very different to Ben Hogan's pelvic motion. Note that the video temporarily stops at the P5.5 position and then continues - note his fluid/continuous rotary pelvic motion between P5.5 and P8. Hogan has a totally different pelvic motion than BW, and there is no advantage to 3-D measurements in terms of understanding their different pelvic motions. One can also easily note that BW uses a CF-arm release action while Hogan uses a CP-arm release action. Jeff.
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Post by imperfectgolfer on Nov 23, 2012 10:05:14 GMT -5
BM wrote-: "My whole point in using any of this stuff is to blow up the goofy theory of the pelvis continuing to turn with no decel.
It can't.
It doesn't.".
Wulsy then wrote-: "The idea that the pelvis doesn't decel is so absurd that those promoting it are just making an arse of themselves."
This Hogan video shows that BM is wrong and that Wulsy is an arse.
Hogan's pelvis doesn't decelerate between P5.5 and P8.
There are a number of pro goflers who have a similar non-decelerating pelvic motion.
Note that Shawn Clement's pelvis doesn't decelerate in his one-leg swing action. His pelvis is in constant motion around the axis of his lead leg in this one-leg swing action.
There is a great advantage to having a continuous (non-decelerating) pelvic motion - as SC demonstrates - if one wants to have an ultrafluid arm/clubshaft swing action. Note that one doesn't have to decelerate the pelvis to release the club efficiently and fluidly. As long as one releases PA#4 fast and efficiently by rotating the upper torso/shoulders appropriately, and also shapes the hand arc path and speed of hand motion along that hand arc path to optimise the efficient CF-release of the club, then one doesn't have to decelerate the pelvis in the late downswing. Pelvic deceleration is an optional, and not an imperative, biomechanical technique.
Jeff.
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Post by tomdavis76 on Nov 23, 2012 13:53:39 GMT -5
Well played, sir!
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Post by tomdavis76 on Nov 23, 2012 17:06:45 GMT -5
Jeff-
I linked to this thread on my site as well as Richie's but those who aren't members here can't see it, and, when they try to register, they get a message saying membership is closed. Do you want to open it up for some new members???
Jeff
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Post by imperfectgolfer on Nov 23, 2012 18:32:54 GMT -5
Jeffy,
Rand Smith (administrator) controls the membership. I will e-mail him to see if he will open it up for new members and guests.
Jeff.
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Post by tomdavis76 on Nov 23, 2012 21:55:14 GMT -5
Jeffy, Rand Smith (administrator) controls the membership. I will e-mail him to see if he will open it up for new members and guests. Jeff. Great! Let me know. Your analysis is devastating. Others should see it. Jeff
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Post by imperfectgolfer on Nov 23, 2012 22:38:28 GMT -5
Jeffy,
Feel free to copy my post and post it on my behalf in your golf forum.
Anybody who watches Shawn Clements hit his 5 iron >200 yards while swiveling his pelvis non-stop (without any deceleration) around his lead leg (in his one leg swing drill) should realize that pelvic deceleration is not an imperative when executing a good swinging action.
Jeff.
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