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Post by imperfectgolfer on Nov 27, 2012 10:35:25 GMT -5
Art wrote the following in Jeffy's forum.
"The primary discussion HERE seems to me based on whether or not the pelvis decelerates through impact, and to my scientific systems understanding, the answer is YES, it has to if the torso and elements above it are to achieve higher angular velocities, ESPECIALLY THE TORSO.
The reason is simply that to achieve a higher torso angular velocity, torque has to be added ABOVE the pelvis, thereby pushing back, and slowing it down. If as your comments infer, a golfer with more pelvic strength swings, they COULD over-power the torso’s ability to accelerate, get ‘stuck’ to the pelvis, but because of the additional inertia and limited range of motion and torque profile of the pelvis, would result in a lower torso angular velocity, therefore lower club head speed."
He believes that the application of torque to the upper torso will slow down the rotation of the pelvis. I presume that he would argue that it works like Cheetam explained with his chair demo - working via a counterforce that operates mainly through the spinal connection between the upper torso and the pelvis. I can certainly imagine this phenomenon happening if the upper torso suddenly starts turning faster than the pelvis due to the application of muscular torque to rotate the upper torso faster. This counterforce phenomenon may explain why Rory has a temporary reversal of pelvic motion at P7.2, and why Bubba Watson has pelvis slowing immediately pre-impact. However, I am not convinced that this phenomenon applies to a significant degree in a golfer - like Ben Hogan - who turns ultra-fluidly with only a limited amount of dynamic torso-pelvic separation (because his upper torso turns soon after the pelvis) and where the pelvis and upper torso rotational motions are better synchronised.
More importantly, any counterforce that works through the spine to decelerate the pelvis in the late downswing will primarily affect the right hip joint (which is unweighted and free-floating in space). I cannot understand how it would significantly affect a golfer's ability to rotate the left hip joint around the firm supportive post of the straightening/braced left leg.
Where is the evidence that Ben Hogan's or Geoff Ogilvey's "left hip clearing action" is decelerating in the later downswing (pre-impact) in the following videos.
Jeff.
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Post by imperfectgolfer on Nov 27, 2012 10:56:53 GMT -5
Consider this "pelvic deceleration" phenomenon from another perspective.
Let's presume that the pelvis decelerates in the late downswing (immediately pre-impact) due to the counterforce phenomenon (secondary to the fact that the upper torso is turning much faster than the pelvis in the later downswing). Would that have any beneficial effect, or would it simply be a secondary biomechanical phenomenon that doesn't affect the arm/club's motion through impact?
Consider Dominic Mazza's swing - when he hits 400 yard drives.
Note how fast he performs a "left hip clearing action". I can see no slowing of his left hip joint's rotational motion pre-impact. However, note that his right pelvis seems to be moving more slowly through impact and its motion looks passive. That could be due to the counterforce phenomenon. Presuming that the counterforce explanation is valid - then it simply means that the slowing of the right pelvis in the late downswing and through impact is a secondary phenomenon. It doesn't mean that the slowing of the right pelvis will affect the arm/club's behaviour in the late downswing and through impact (as BM asserts when he stated that the benefit of pelvic deceleration would affect the club through impact - he specifically stated-: "Start with the fact that you need the top of the handle to go backward.....")
There is another major factor that affects the speed of right pelvis motion in the late downswing - stance width. Mazza has a wide stance and that will impede the free motion of the right pelvis in the later downswing - note how he drags his right foot forward in the followthrough. By contrast, in the video of Geoff Ogilvey - note that he has a narrow stance and note that his right pelvis doesn't seem to slow down much pre-impact. It could also be due to the fact that he is hitting an iron and the magnitude of counterforce phenomenon will be less because he is swinging his upper torso less fast (relative to a driver swing).
Addendum added later:
I have been running Dominic Mazza's swing video through my V1 Home swing analyser - using the toggle control that allows one to manually control the speed of the video. When I toggle repeatedly between the P5.5 and P7 position - I cannot see any slowing of his pelvis motion pre-impact. Can you?
Jeff.
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Post by imperfectgolfer on Nov 27, 2012 20:54:55 GMT -5
See this Jeffy-forum thread. jeffygolf.com/showthread.php?517-Brian-Manzella-Picture/page4Jeffy presented this graph. I question the accuracy of the graphs if they were obtained from that boot-legged video - look at the roller coaster nature of the measurements that required a smoothing algorithm to come to some interpretative conclusion. Also, the BM-bootlegged video seemed to stop just before impact and I am not sure that the graphs represent the P6.8-P7 part of the downswing with great precision. Secondly, Jeffy stated-: " The overall picture is pretty clear: he does what you say shouldn't be done (links the pelvis and torso together and drives them with the pelvis) and doesn't appear to sacrifice much distance as a result". There is nothing in that graph that shows that the pelvis is driving the upper torso. Jeffy is simply expressing his biased opinion re: the nature of Sadlowski's downswing mechanics. It could be that Sadlowski is driving his upper torso rotation independently, but in synchrony with his pelvic rotation. Jeff.
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Post by imperfectgolfer on Nov 27, 2012 22:32:22 GMT -5
See this Jeffy-forum thread. jeffygolf.com/showthread.php?518-Jamie-Sadlowski-s-hip-rotation-into-impactJeffy posted this Tapio-produced graph of a young European tour golfer. I would very much like to see a video of that golfer to understand how his shoulder rotation speed can be so much faster than his pelvic rotation speed between P4 and P5.5+. Jeffy also wrote-: " As far as I'm concerned, this data, as well as the Hogan analysis I did the other day and the 4DSwing analyses shared by Tapio, blows up claims that deceleration is essential to all good golf swings. Deceleration may be the ultimate result in most or nearly all cases, but, IMO, it should be caused by increasing moment of inertia, not decreasing torque." I agree that a golfer should not decrease pelvis-driving torque, but I don't really believe that pelvic deceleration is primarily due to a high MOI of anatomical structures above the level of the pelvis. I think that the most likely reason for pelvic deceleration between P5 and P7 is due to the fact that the left leg becomes increasingly weighted and increasingly straightened/braced. During the "left hip clearing action", one has to rotate the left thigh and left leg counterclockwise, and it becomes increasingly difficult to accomplish that goal as one gets nearer to impact - because the left leg gets increasingly weighted and braced. A few golfers (like Hogan and Mazza) can externally rotate the left thigh to an amazing degree despite this weight-loading situation, but most golfers cannot accomplish that goal and they decelerate their pelvis in the later downswing (especially if they keep their left foot solidly grounded and don't allow their left foot to externally rotate against the surface of the ground (like Bubba Watson). Here is Mazza at the P7.3 position. Amazingly, the front of his left knee (patella) is facing the target - despite the fact that his left foot is still solidly grounded and there is no significant external rotation of his left foot. That requires an inordinate degree of flexibility that most professional golfers do not exhibit! Jeff.
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Post by tomdavis76 on Nov 27, 2012 23:51:00 GMT -5
See this Jeffy-forum thread. jeffygolf.com/showthread.php?517-Brian-Manzella-Picture/page4Jeffy presented this graph. I question the accuracy of the graphs if they were obtained from that boot-legged video - look at the roller coaster nature of the measurements that required a smoothing algorithm to come to some interpretative conclusion. No it didn't. The near perfectly linear slope of the hip rotation plot is all that is needed to know what is going on. Yep, lot's of issues with it, but you play the hand that's dealt. Art stated that the pelvis must decelerate and give way to the torso, or it would disrupt the timing, balance, etc. of the downswing. Since the pelvis doesn't give way (i.e., it's NOT decelerating), it must be driving, unless Art is full of shit, which is always possible.
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Post by tomdavis76 on Nov 27, 2012 23:52:20 GMT -5
See this Jeffy-forum thread. jeffygolf.com/showthread.php?518-Jamie-Sadlowski-s-hip-rotation-into-impactJeffy posted this Tapio-produced graph of a young European tour golfer. I would very much like to see a video of that golfer to understand how his shoulder rotation speed can be so much faster than his pelvic rotation speed between P4 and P5.5+.Jeffy also wrote-: " As far as I'm concerned, this data, as well as the Hogan analysis I did the other day and the 4DSwing analyses shared by Tapio, blows up claims that deceleration is essential to all good golf swings. Deceleration may be the ultimate result in most or nearly all cases, but, IMO, it should be caused by increasing moment of inertia, not decreasing torque." I agree that a golfer should not decrease pelvis-driving torque, but I don't really believe that pelvic deceleration is primarily due to a high MOI of anatomical structures above the level of the pelvis. I think that the most likely reason for pelvic deceleration between P5 and P7 is due to the fact that the left leg becomes increasingly weighted and increasingly straightened/braced. During the "left hip clearing action", one has to rotate the left thigh and left leg counterclockwise, and it becomes increasingly difficult to accomplish that goal as one gets nearer to impact - because the left leg gets increasingly weighted and braced. A few golfers (like Hogan and Mazza) can externally rotate the left thigh to an amazing degree despite this weight-loading situation, but most golfers cannot accomplish that goal and they decelerate their pelvis in the later downswing (especially if they keep their left foot solidly grounded and don't allow their left foot to externally rotate against the surface of the ground (like Bubba Watson). Here is Mazza at the P7.3 position. Amazingly, the front of his left knee (patella) is facing the target - despite the fact that his left foot is still solidly grounded and there is no significant external rotation of his left foot. That requires an inordinate degree of flexibility that most professional golfers do not exhibit! Jeff. Here's a hint: it's Alex Noren.
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Post by imperfectgolfer on Nov 28, 2012 0:56:02 GMT -5
Jeffy,
You wrote-: "Art stated that the pelvis must decelerate and give way to the torso, or it would disrupt the timing, balance, etc. of the downswing. Since the pelvis doesn't give way (i.e., it's NOT decelerating), it must be driving".
I now understand what you are implying, and I think that's a good point. I cannot understand why Art believes that the pelvis must decelerate to allow a golfer to remain in dynamic balance during the downswing action.
You also wrote-: "No it didn't. The near perfectly linear slope of the hip rotation plot is all that is needed to know what is going on."
Another solid point! I certainly gained a visual impression that there was no pelvic deceleration between P4 and P6.8 when I used the manual toggle of the V1 Home swing analyser on a face-on Sadlowski swing video.
Jeff.
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Post by imperfectgolfer on Nov 29, 2012 1:54:43 GMT -5
See this Jeffy forum thread. jeffygolf.com/showthread.php?518-Jamie-Sadlowski-s-hip-rotation-into-impact/page2Congratulations to Jeffy - because he is right, and BM and the BM groupies are floundering about in an abysmal state of mental confusion! Mike Finney is hysterical and off-the-wall because he is worried about depth-of-field and parallax distortion in Jeffy's measurements of a birds-eye view video of Sadlowski. However, the front of the camera lens must be roughly parallel to the posterior pelvis rim in a birds-eye view video, and if the pelvis rotates relatively horizontally, then the posterior pelvic rim should remain parallel to the camera lens throughout the downswing, thereby making measurements of angular velocity of the pelvis reasonably (sufficiently) accurate. Jeff.
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Post by tapiosantala on Nov 29, 2012 2:47:34 GMT -5
Nice posts there. I mostly enjoyed that wulsy's post and Jeffys reply for that ;D #380
I'm just making one sheet that will maybe get me more enemies from both sides, but maybe also help people to understand this better. What it seems to tell clearly, is that it really doesn't matter if you decelerate your hips or not, you still can get same kind of results. So it destroys the kinetic chain theory, but also tells that there is not real benefit to accelerate the hips (as I still want my students to fire them as hard they can)
Don't want to say too much before I collect more data and check it carefully, but it really seems that only thing that matters is how much total force player can create against the ground at some moment before impact and ends up totally to hand speed max also achieved at some moment of DSW.
Correlation of that max hand speed and CHS seems to be very clear and the variation at that sheet about that is very very small. At the same time, the variations of timing and rotation speeds of the hips and shoulders varies a lot between different players.
So it also seems to prove that all those BMans cases are based on only few or one pro and they are showed against just one or few amateurs that fit to their agenda. It seems they really don't want to show those who do it differently and still get the same result. And it seems it's same with TPI as I have seen so many players hitting great shots and being "out of sequence" as they call it.
And still bit of backround to this post:
Last 4-5 years with 4DSwing my main work has been searching the "silver bullet" that we could tell people to achieve. As I think everyone understands, it would be great advantage for me and for us to find it and be able to tell people what they should do. I have found few great things during that trip, but also haven't been able to find any proof that some kind of sequence or acc / dec of different segments could be one. Players are doing it different ways and still produce same kind of hand speed and CHS, so there is not at all one way to do it.
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Post by imperfectgolfer on Nov 29, 2012 10:33:42 GMT -5
BM wrote in his forum-: "There are other folks in golf land that disagree with the hip slow down and even disagree with the marker capture systems.
Since I have a student with a +5 handicap and about 115+ mph clubhead speed that wants to have his swing captured on a high-end 3D system, and Dr. Wurzer and Art Maffei both have suggested that all interested parties get together for a capture/analysis session, and they are in Southern Cal, not too far from the major manufacturers and research universities. We are going to set up a day for some 3D + other technology session. Also, Billy McKinney is close by and may have another high-end student to capture."
His testing is going to produce a pre-ordained result - that the pelvis decelerates in the late downswing because that is the pattern manifested by >95% of professional golfers. BM really needs to test golfers like Sadlowski. Mazza, and Noren who don't decelerate. If he shows that there are a few golfers who don't manifest pelvic deceleration in the late downswing, then his theory that pelvic deceleration is a mandatory biomechanical phenomenon in a skilled golfer has been falsified.
I am still waiting for BM to explain why he deems pelvic deceleration mandatory. I agree with Tapio - that there are patterns of pelvic motion in the downswing, and that most golfers manifest pelvic deceleration pre-impact (for biomechanical reasons that I have supplied in previous posts) but that some golfers do not decelerate their pelvic rotation pre-impact. I know of no evidence that proves that golfers who don't manifest pelvic deceleration pre-impact will be able to increase their clubhead speed as result of that pelvic motion pattern. Most of the long-hitters on the PGA tour decelerate their pelvis pre-impact eg. Bubba Watson, Dustin Johnson, and Nicolas Colsaerts.
Jeff.
p.s. Jeffy - here is another golfer who may not decelerate his pelvis pre-impact
JB Holmes.
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Post by tomdavis76 on Nov 29, 2012 11:03:00 GMT -5
We love JB! Really uses the spine the correct way.
Jeff
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Post by tapiosantala on Nov 29, 2012 11:07:41 GMT -5
The worst thing in all this is that people really start to believe that they have to stop their hips to create high CHS. I have seen too many players destroyed already with that idea that there is really no more needed.
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Post by gmbtempe on Dec 11, 2012 9:10:01 GMT -5
Watch this insane video by BM. vimeo.com/54171919#BM is so stupid and his constant, taunting "smiling-attitude" in that video is so irritating and insulting. I think that he is living in a mental bubble that is detached from objective reality. He thinks that his placement of colored time-points reflects pelvic rotational velocity - when viewing a 2-D video where the camera is placed directly behind the golfer. That's insane!!! The left buttocks moves inside-left in the early downswing and then progressively more backwards (away from the target) in the mid-late downswing, but by the later downswing (when the pelvis is progressively more widely open to the ball-target line) it will appear to be moving less backwards (away from the target) even if the rotational speed is constant. That will cause the time-points to get progressively closer together - even if rotational velocity remains constant. Consider this diagram. I have placed a red dot on the left posterior pelvic crest. Let's presume that pelvic rotational speed remains constant between P5 and P7.5 - from that camera viewing angle the distance that the red dot travels between P6.5 and P7.5 per unit time is obviously going to " seem" to be progressively less. Secondly, he thinks that he is demonstrating that the pelvis is slowing down (decelerating) just before impact. However, by the time Sadlowksi reaches the P6.7 position, his pelvis is so open to the ball-target line that it cannot possibly continue to rotate at the same speed as it was rotating from P4 to P6.7. That doesn't reflect any deliberate pelvic deceleration phenomenon. The same phenomenon occurs in Bubba Watson's swing - he accelerates his pelvis so fast in the early-mid downswing that he already has a wide open pelvis near impact, and therefore it "appears" that his pelvic rotation speed is slowing down between P6.7 and P8, but that only reflects the "fact" that BW (like JS) completes most of his "functional" pelvic rotation activity before impact. If one really wanted to visually see how much the pelvis rotates per unit time in the downswing, then one needs a birds-eye view camera angle where the camera is at right angles to the pelvic crest and parallel to the "apparent" axis of pelvic rotation. Jeff. p.s. Jeffy - feel free to copy any of my posts to your golf forum. Though I don't agree with the Bman statements, I will just say I disagree. I agree with this post more than most of yours, the statements reflect my mental reality on this subject.
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Post by imperfectgolfer on Dec 14, 2012 10:09:40 GMT -5
See this BM-forum thread - www.brianmanzella.com/golfing-discussions/17915-would-guy-hit-farther-if-he-quit-stalling.htmlMF stated with respect to the golfer in this next video-: " would this guy hit it farther if he quit stalling.... or does he hit it far because he stalls....??" MF is implying that this golfer stalls his pelvic motion. I disagree - because I define reality differently. To assess pelvic rotation during the left hip clearing action, I look at the i) rotary motion of the left pelvis in a counterclcokwise direction and the ii) counterclockwise rotation of the left upper thigh. I can see no slowing of the rotation of those two elements in the downswing. In fact, one can see the golfer spinning his left foot through/after impact because he has such an active counterlockwise rotation of the left left thigh/leg during the late downswing and through impact. Jeff.
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Post by gmbtempe on Dec 14, 2012 12:00:49 GMT -5
His pivot and legwork are pretty similar to this guy, finish is a little different.
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