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Post by dubiousgolfer on Jun 5, 2023 16:46:09 GMT -5
Dr Mann
What are your opinions regarding AMG's recent video about forward shaft lean?
DG
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Post by imperfectgolfer on Jun 5, 2023 23:39:19 GMT -5
Dr Mann What are your opinions regarding AMG's recent video about forward shaft lean? DG I cannot fathom why the AMG instructors believe that there is no right-to-left motion of the hands across the front of the body between P5.5 => P7. Here is Dustin Johnson's hand arc path. Image 2 is at P5.5 and image 3 is at P7. It is clear to me that DJ's lead arm is more abducted in image 3 compared to image 2 (relative to his upper chest).
I also cannot understand their claim that the hands are opposite the trail body at impact -as depicted at the 5:17 minute time point of their video. Of course, it may by opposite the trail hip if the pelvis is significantly rotated counterclockwise at impact, but the hands are opposite the lead shoulder at impact and not the trail shoulder - as evident in image 3 above. The hands at impact are also much closer to the lead foot than the trail foot at impact. I have no idea why the AMG instructors are producing this video! Jeff.
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janik
Full Member
Posts: 143
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Post by janik on Jun 6, 2023 4:16:41 GMT -5
Hi Dr. Mann,
It is interesting because to my eyes DJ’s hands have not passed his sternum at impact and are equidistant (more or less) between both shoulders. Of course that is relative to a rotating torso.
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Post by dubiousgolfer on Jun 6, 2023 7:04:30 GMT -5
Dr Mann Maybe this facebook video makes it clearer why they think the hands do not move much across the body from P5.5-P7 . m.facebook.com/AthleticMotionGolf/videos/3855849617866173/?locale=ms_MYHow would one discern between pure lead arm adduction across the chest v scapula protraction causing the lead arm to move across the chest (as per video below)? Would one need to have a birds-eye view of the golfer to see how their scapula moves? Similarly how would one know whether the golfer is applying pure lead arm abduction or scapular retraction during the downswing? DG PS . It seems that GEARS has some extra functionality to view scapula and clavicle movements compared to their older video below from 7:55 which showed 'pure lead arm adduction' and no mention of lead scapula protraction.
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Post by imperfectgolfer on Jun 6, 2023 7:55:02 GMT -5
Hi Dr. Mann, It is interesting because to my eyes DJ’s hands have not passed his sternum at impact and are equidistant (more or less) between both shoulders. Of course that is relative to a rotating torso. To assess whether DJ is abducting his lead arm between P5.5 => P7, you should look at his lead elbow (and not his hands). His lead elbow is behind his sternum at P5.5 and in front of his sternum at P7. Jeff.
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Post by dubiousgolfer on Jun 6, 2023 8:11:12 GMT -5
There is definitely movement of the elbow/hands across the chest in the downswing from P5.5-P7 (maybe 5-7 inches), because their facebook video proves it .
DG
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Post by imperfectgolfer on Jun 7, 2023 11:08:25 GMT -5
Dr Mann Maybe this facebook video makes it clearer why they think the hands do not move much across the body from P5.5-P7 . m.facebook.com/AthleticMotionGolf/videos/3855849617866173/?locale=ms_MYHow would one discern between pure lead arm adduction across the chest v scapula protraction causing the lead arm to move across the chest (as per video below)? Would one need to have a birds-eye view of the golfer to see how their scapula moves? Similarly how would one know whether the golfer is applying pure lead arm abduction or scapular retraction during the downswing? DG PS . It seems that GEARS has some extra functionality to view scapula and clavicle movements compared to their older video below from 7:55 which showed 'pure lead arm adduction' and no mention of lead scapula protraction. The AMG video on scapular protraction/retraction is intellectually interesting, but I cannot envisage how it helps from a golf instructional perspective. I can easily imagine that flexible pro golfers have more scapular motion than inflexible amateur golfers. However, I know of no scientific reasoning that shows that significant variations in the degree of scapular motion among pro golfers is better, or not better, in terms of their downswing's overall body/arm biomechanical motions and/or in terms of their capacity to generate maximum clubhead speed or ball flight accuracy. I think that the AMG's video on clubhead lag is full of errors. I can understand how cupping the lead wrist during the P1 => P6 time period can affect the clubface angle, but I cannot understand why the AMG instructors believe that it will diminish a golfer's ability to retain a greater clubhead lag angle at P6. In fact, I think that cupping the lead wrist allows a golfer to radially deviate the lead wrist more and create a greater degree of clubhead lag. Ben Hogan had a very cupped lead wrist from P4 => P5.5, with an open clubface that Mike Granato calls a "weak clubface" between the 6:00 - 6:26 minute time point of his video, but he had no problem maintaining a large degree of clubhead lag between P4 => P5.5. Animated gif of Ben Hogan's downswing Note that Hogan has a very cupped lead wrist at P5.5 in image 1 and yet he has a large clubhead lag angle. I can accept an opinion that pro golfers have a smaller amount of change in their degree of lead arm abduction between P4 => P6 (compared to amateur golfers), but I cannot perceive how that difference can be casually responsible for increasing a golfer's ability to retain more clubhead lag at P6. I think that a major factor that affects the degree of clubhead lag at P6 is the degree of straightening of the trail arm between P4 => P6. I think that an active trail upper arm adduction maneuver combined with a good pitch elbow motion of the lead arm makes it easier to retain a greater amount of clubhead lag at P5.5 - as seen in Hogan's image at the P5.5 position where his hands are about 12" outside his trail thigh at P5.5.
Note how his hands moves targetwards between P5.5 => P6 as he increasingly straightens his trail elbow/internally rotates his trail upper arm and when he increasingly abducts his lead arm (note how his lead elbow moves from being behind his sternum at P5.5 to becoming ahead of his sternum at P6 - and it is not solely due to body rotation, but due to a lead arm abductory motion that creates a "wiping action). Jeff.
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Post by dubiousgolfer on Jun 8, 2023 6:13:40 GMT -5
Many thanks Dr Mann I think AMG are making an assumption that amateur players might be making 'false' upper body turn by pure lead arm adduction (without using lead scapular protection and trail scapular retraction). By doing this , they will tend to bend their lead and trail arms more and therefore create a situation where their hands are too close to the trail shoulder and not enough in front of their sternum. There is an article about this below. ------------------------------------------------ golf.com/instruction/state-of-the-art-technology-reveals-the-10-biggest-golf-swing-killers/4. Fishing For Depth Trying to pull your lead arm deep behind you early in the backswing is a trend we see cause a lot of issues. Our two golfers here are at left arm parallel in the backswing. Notice how the amateur has more than doubled his left arm depth compared to our pro. This tends to cause a loss of width and an overly bent right arm as you reach the top. When that happens, your rotation will suffer and you’ll be forced to make several compensations in your downswing. Instead, try to preserve as much width as possible going back allowing your turn to take care of the depth. You’ll have a much more powerful downswing when you do it. 5. Collapsing Your Trail Arm Nearly all the pros Webb and Granato studied measured between 55 and 85 degrees of right-arm bend at the top of the backswing. By comparison, most of the amateurs they’ve captured fall between 95 and 125 degrees. That’s a big power leak. Your right arm is a major acceleration source at the start of the downswing, and the straighter you keep it on the way back, the more likely you’ll increase your shoulder turn (another power source). Webb and Granato report that students who worked on keeping their trail arm straighter picked up an additional 30 degrees of shoulder rotation — even those aged 65 and older! ----------------- I'm unsure why a longer right arm can provide more linear acceleration of a club than a bent one at the start of the downswing. Maybe it forces the upper right arm to be further away from the right side of the torso which then allows a greater amount of 'right arm adduction/pitch elbow' actions (ie. this would mean the right arm applying a pulling force on the club's grip over a longer path ). DG
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