Post by imperfectgolfer on Nov 18, 2019 12:00:51 GMT -5
Consider this AMG video.
Stop the video at the 11:46 minute time point where Shaun Webb states that the clubshaft should be straight-in-line with the left arm at that followthrough time point. That phenomenon would be seen in a DHer who doesn't continue to supinate the left arm post-impact, which would cause the clubshaft to bypass the left arm during the early followthrough. That advice (which I can strongly endorse) contradicts their advice given in the following AMG video where they advise golfers golfers to continuously supinate their left forearm through impact.
I wonder whether they can comprehend the contradiction in the different/contrary advice that they offer in their different golf instructional videos.
Post by imperfectgolfer on Nov 18, 2019 13:13:32 GMT -5
More commentary on the lack of insight into golf swing biomechanics manifested by the AMG instructors.
Consider the following AMG video.
In that video, Shaun demonstrates that if one relaxes the wrists/hands that the clubface will not automatically square up during the release of PA#2 and both AMG instructors state that a golfer must apply a twisting force to the grip in order to square the clubface by impact. However, they do not describe how the twisting force should be applied, and Shaun only states that it should be applied in the early downswing. How is it biomechanically possible to apply a twisting force phenomenon to the clubshaft in the early downswing? In another AMG video, Shaun describes how to perform the reverse motorcyle move, which can produce a twisting roll of the clubshaft in the early downswing that will close the clubface relative to the clubhead arc. However, a reverse motorcycle move is rarely used in pro golfers.
Let's examine the AMG GEARS-video contained in the AMG video above - featuring a pro golfer.
Image 1 shows the golfer at the P5.5 position. I have drawn three red dots over his left lower radial bone to show that his left forearm is pronated at the P5.5 position. Why must the left forearm be pronated at the P5.5 position? The correct answer is that if a golfer has an intact LFFW and the clubshaft is angled back away from the ball-target line, then that scenario is only biomechanically possible if the left forearm is pronated so that the back of the GFLW is straight-in-line with the angled-back clubshaft. Note that the golfer has a GFLW with no evidence of a twistaway maneuver (reverse motorcycle maneuver) and note that the clubface is parallel to the back of his GFLW and wide open relative to the clubhead arc. In other words, that pro golfer is not twisting the clubshaft, and therefore the clubface, closed during the early downswing - as the AMG instructors recommend.
So, how does this pro golfer get a square clubface by impact? The answer can be seen in image 2. Note that I have drawn three red dots over his lower left radial bone and one can clearly discern that his left lower forearm is much more supinated (compared to image 2) while his left humerus is still internally rotated. So, left forearm supination (happening between P5.5 and impact) is the biomechanical method that pro golfers routinely use to square the clubface relative to the clubhead arc, and yet the AMG instructors offer no advice on how a golfer should accomplish that goal in this video. Note that the clubface is straight-in-line with his left lower radial bone, which is expected if a golfer still has an intact LFFW.
Look at image 3 showing the pro golfer at the P7.5 position. Note that the clubshaft is straight-in-line with his left arm, which fits the definition of a DH-hand release action, and which allows the golfer to keep the clubface square to the clubhead arc between P7 and P7.5. I have drawn three red dots over his left lower radial bone and it shows that the pro golfer is not continuing to supinate his left forearm between impact and P7.5. So, how does he control the finite amount of roll of his clubface between P7 and P7.5 that is needed to allow his clubface to remain continuously square to his clubhead arc? The correct answer is that he is rotating his left humerus externally in a very controlled manner that causes the entire intact LAFW to roll as an intact left arm-clubshaft unit so that the clubface remains square to the clubhead arc - and that represents the delayed full-roll subtype of DH-hand release action used by many pro golfers. Note that his clubface is still straight-in-line with his left lower radial bone, which is expected if one has an intact LAFW.
It is amazing to me that the AMG instructors have access to so many GEARS-produced videos of the golf swing actions of pro golfers, and yet they are still intellectually clueless about what those videos are actually showing regarding the golf swing biomechanics manifested by pro golfers.
p.s. If you want to more clearly see the red dots in those capture images, then first right-click on the image and then choose "view image". Then, repeatedly click on the "control" key plus the "+" key to enlarge the capture images.
Post by dubiousgolfer on Nov 18, 2019 18:38:33 GMT -5
Have Gears improved the accuracy of their "left wrist extending" and "left forearm supination" since your last conversation with Michael Neff?
If they haven't then can one really use their Gears Avatars for analysing the above biomechanical events (unless we also knew who the golfer was and could also compare to the video footage like you did with Jamie Sadlowski below)?
PS. Looking again at that Michael Neff video , he has placed a marker on the elbow . Can't the relationship of the orientation of the 'left wrist marker' vs 'elbow marker' provide a measurement of left forearm supination?
---------------------------- I had a 1-hour Skype conversation with Michael Neff, owner of the GEARS 3-D system, yesterday. I was hoping to discover how his GEARS system could measure the amount of "left wrist extending" and "left forearm supination" happening between P7 and P7.2. What I discovered is that the standard GEARS 3-D motion analysis system cannot even measure those biomechanical events because they do not have any markers on the left hand or left lower forearm's radial bone.
Here is a video showing how one places the markers in place.
Note that there is only a single marker placed on the back of the lower left forearm, but that there are no markers on the back of the left hand or on the left lower radial bone and the middle of the left antecubital fossa. Therefore, the GEARS system cannot be used to measure the amount of "left wrist extending" and "left forearm supination" happening between P7 and P7.2.
To get an idea of how the GEARS-avatar system "invents" biomechanical events that do not correlate with reality - consider this video showing the GEARS analysis of Jamie Sadlowski's golf swing.
Here are comparison capture images of a 2-D capture image of Jamie Sadlowski at impact versus the GEARS avatar.
At impact, Jamie Sadlowski's ulnar border of his left hand faces the target because he uses a very strong (4-knuckle) left hand grip, while the back of his left hand is roughly parallel to the inclined plane while it faces the ball-target line. Note that the clubface is square to the target at impact, which means that the clubface is angled about 60 degrees closed relative to the back of his left hand (as it was at address). However, note that the back of the GEARS-avatar's left hand faces the target and it is parallel to the clubface.
Here is another comparison image at P6.
Note that the clubface is slightly tilted beyond vertical, but it is about 45 degrees closed relative to the back of his left hand (blue line).
In other words, the GEARS avatar's left wrist/hand motions have no correlation with reality. The GEARS system accurately measures the clubface angle because there are 3 markers on the clubhead, but it artificially "invents" the position of the left wrist/hand.
I spoke to Michael Neff about placing more markers on the back of the left hand, over the left lower radial bone at the level of a watchband and over the middle of the left antecubital fossa, so that the GEARS system can accurately measure the amount of "left wrist extending" and "left forearm supination" happening between P7 and P7.2. "Time" will tell whether he is responsive to my suggestions and whether a future GEARS motion analysis system has this capability.
An interesting tidbit of information. I asked Michael Neff how he checks to see whether his GEARS system can accurately measure the position of the clubshaft, clubhead, clubface and body parts at every moment of the golf swing - by using another measuring device - and he stated that he uses a Phantom camera operating at 20,000 FPS as a "gold standard" check. I wonder what the "flat-earthers" at Golf WRX will think when they read about that interesting tidbit of information!
Post by imperfectgolfer on Nov 18, 2019 20:09:07 GMT -5
You asked-: "Have Gears improved the accuracy of their "left wrist extending" and "left forearm supination" since your last conversation with Michael Neff?
If they haven't then can one really use their Gears Avatars for analysing the above biomechanical events (unless we also knew who the golfer was and could also compare to the video footage like you did with Jamie Sadlowski below)?"
I have no evidence that GEARS have improved the accuracy of their avatar-images and those capture images may therefore not be reflective of reality seeing that we do not know that pro golfer's name. However, they are exactly what one would expect in "real life" if that pro golfer adopted a neutral left hand grip and performed a DH-hand release action through impact - based on my extensive review of many swing videos taken from multiple angles. Therefore, those capture images can reasonably be used as a generic example of what should happen in a pro golfer's golf swing action if he uses a neutral left hand grip and uses a delayed full-roll hand release action through impact.
You also asked-: "Looking again at that Michael Neff video , he has placed a marker on the elbow . Can't the relationship of the orientation of the 'left wrist marker' vs 'elbow marker' provide a measurement of left forearm supination?"
No. The markers would have to be placed in the center of the left antecubital fossa and over the left lower radial bone (at the level of a watchface).