Post by imperfectgolfer on Mar 17, 2015 11:06:21 GMT -5
See this BM-article that featured in the latest issue of Golf Digest.
www.golfdigest.com/golf-instruction/2015-04/3-moves-to-smash-it
Clay Davidson has already commented on the stupidity of BM's reasoning in a Jeffy forum thread - jeffygolf.com/showthread.php?1443-3-Errors-Golf-Digest-Style - but he doesn't go far enough in his criticism.
BM claimed that tour players use those three torques (alpha, beta and gamma) to increase clubhead speed, but I think that it is impossible to significantly increase clubhead speed by using any beta or gamma torque. Gamma torque is simply due to a left forearm supinatory action that happens between P6 and P7, and it is used to square the clubface by impact. However, I know of no mechanism that can allow a "twisting action of the clubshaft around its longitudinal axis" to increase clubhead speed, other than an insignificant amount due to a rotation of the sweetspot around the hosel. The distance between the sweetspot and the hosel is only ~2" and if you multiply that distance by the degrees/second rotation that happens between P6 and P7, then the amount of clubface closing force is negligible (compared to the clubhead speed derived from the sequential release of PA#4 => PA#2).
BM also claims that a clubshaft-shallowing action (torque in the beta plane) increases clubhead speed, but He doesn't explain how that is possible. In his article, BM makes the following three wrongheaded statements-: "In a good downswing, the lower body shifts left and then the upper body turns and pushes into the left arm, which pitches the club into a slightly flatter, more horizontal position. From there, you can turn hard and use the right side of your body to produce extra speed. As your hands move closer to your body near impact, the club whips in line with your left arm—the bit of turbocharging at the bottom that tour players use to get extra distance". How can the upper body turn push into the left arm in such a manner that it causes the clubshaft to shallow-out? How can a golfer use the right side of the body to produce extra CH speed? His 3rd claim that the hands getting closer to the body near impact whips the clubshaft into line with the left arm is a BS-claim! The clubshaft gets into line with the left arm by low point due to the release of PA#2, and not due to any decrease in hub path radius (which can only add a limited element of parametric acceleration in golfers who have a decreasing hub path radius near impact).
I believe that the clubshaft-shallowing action (which happens to variable degree in pro golfers) is due to a variable rate of right arm adduction that happens between P4 and P5.5 and that biomechanically causes the right elbow to drop groundwards faster than the left elbow per unit time.
Consider two examples.
Henrik Stenson
![](http://perfectgolfswingreview.net/StensonHandArcPath.jpg)
The red curved line represents his hand arc path. The straight blue lines are drawn through the two elbows to show their respective degree of downward movement during the early-mid downswing.
Henrik Stenson is an example of a golfer who gets his left arm across his shoulder turn angle at his end-backswing position with his hands very close to the TSP, and who gets his hands/clubshaft down to the elbow plane by the P5.5 position (image 3).
Note that Henrik Stenson's left elbow is slightly higher than his right elbow at the P4 position (image 1).
Note how Henrik Stenson actively adducts his right upper arm at the start of his downswing action (image 2) and note how his right elbow drops slightly more down below the level of his left elbow. It is that differential degree of movement of the right elbow (relative to the left elbow) that causes the clubshaft to shallow-out in his early downswing. Because the degree of dropping of his right elbow (relative to his left elbow) is very small, there is very little clubshaft shallowing-out effect - and his clubshaft plane in his early downswing is only slightly shallower than his clubshaft plane in his late backswing. Note that Henrik Stenson's hands move significantly downwards, and far less outwards (in the direction of the ball-target line), in his early downswing (image 2).
Image 3 shows Henrik Stenson at the P5.5 postion. Note that his hand arc path between P4 and P5.5 is steeper than the clubhead arc path.
Now, consider the hand arc path and clubshaft shallowing-out action of Ryan Moore.
Ryan Moore swing video - www.youtube.com/watch?v=_m3lCmj9yrU
Here are capture images from the swing video.
![](http://perfectgolfswingreview.net/MooreHandArcPath.jpg)
The red curved line represents his hand arc path. The straight blue lines are drawn through the two elbows to show their respective degree of downward movement during the early-mid downswing.
Image 1 shows Ryan Moore at the end-backswing position. Note how steep his left arm is angled with his hands positioned high above his right lateral clavicle area. Note that both elbows are nearly level, with his right elbow slightly higher than his left elbow.
Image 2 shows how actively Ryan Moore adducts his right upper arm in his early downswing and note how that causes his right elbow to drop well below his left elbow. Note how that large differential degree of movement of the right elbow (relative to the left elbow) shallows-out his clubshaft. While that is happening, note that his left forearm must be pronating more so that his intact LAFW can become parallel to a shallower downswing plane, and this left forearm pronation phenomenon happens passively/subconsciously. Note that he maintains an intact LAFW (left arm-clubshaft remain straight-line-aligned) and a GFLW during his clubshaft shallowing-out action. Note that this active right arm adduction motion (that drops the right elbow well below the left elbow) causes the right humerus to become externally rotated. However, note that the right forearm is not affected and it remains neutral. Note that his hands have mainly moved downwards/groundwards and not outwards (in the direction of the ball-target line) - in fact, if you look carefully you will note that his hands have actually moved slightly backwards (away from the ball-target line).
Image 3 shows Ryan Moore at the P5.5 position and he looks very similar to Henrik Stenson at the P5.5 position. If you compare their hand arc paths, they look very similar between P5 and P5.5, but Ryan Moore's hand arc path is much more vertical, and even angled slightly backwards (away from the ball-target line), between P4 and P5. The important golf instructional lesson to be learned from this downswing comparison is that it is very important for a golfer, who has "high hands" at the P4 position (like Ryan Moore), to actively adduct the right arm and drop the right elbow below the left elbow - if he wants to shallow-out the clubshaft (like Ryan Moore). A major swing fault would be to move the hands outwards (in the direction of the ball-target line), rather than primarily downwards, at the start of the downswing as this would predipose to an OTT-move and an out-to-in clubhead swing path during the later downswing. Most importantly, the clubshaft-shallowing action, which affects the plane of the clubshaft in the beta plane, cannot increase clubhead speed. How could it? BM provided "no evidence" to bolster his wrongheaded claim that " a clubshaft-shallowing action" can increase clubhead speed.
Finally, how can PA#2 release (clubshaft motion in the alpha plane) increase clubhead speed? BM wrongly asserts that a golfer has to use a positive wrist torque from an active contraction of left-and-right arm muscles to induce the release of PA#2 (ulnar deviation in the plane of an intact LAFW). He provides "no evidence" to support that claim. He wrongly refers to Steve Nesbit, but SN did not discuss the production of any positive wrist torque in his article - see "Kinematic analysis of the golf swing hub path and its role in golfer/club kinetic transfers" by Steven Nesbit and Ryan McGinnis, which is available as a pdf file at www.jssm.org/vol8/n2/11/v8n2-11pdf.pdf. Steve Nesbit openly states in his hub path paper that one cannot clearly discern what causal "forces" are in play during the club-releasing phenomenon that occurs during phase 2 - when he wrote-: "For all subjects, the initiation of phase II coincided with their first local hub radius minimum, while applying the majority of their respective maximum swing torque, and reaching about half of their respective maximum grip velocity. Acting together these effects increased the centrifugal loading on the club and initiated the rapid outward or uncocking movement of the wrists/club relative to the hub path. During phase II, as the club moved outward, the wrist torques continued to increase accelerating the angular motion of the club. The increase in hub path radius during this phase may be a result of the golfer shifting the effort from controlling the hub path to applying maximum wrist torque, or it could simply be a third-law reaction to the rapid outward movement of the club". In other words, Steve Nesbit is stating that the application of a swing torque that induces the release of PA#4 (release of the left arm which causes the left hand to move along the hand arc path), combined with a "tighter" hand arc path curve during phase 2 of the downswing, causes the club to *centrifugally release. He also states that any increase in hub path radius during the latter part of phase 2 could be due to a third-law reaction to the rapid outward movement of the club and not due to the application of any wrist torque. BM also wrongly infers in his GD-article that he can discern the presence of a positive wrist torquing force phenomenon from the GEARS system when he stated-: "Using the Gears Golf system for tracking body and club movement—the same technology that produced the 3-D swing images in this story—we're able to pinpoint the moves that create those torques and compare them from player to player." How can the GEARS system, which is merely a 3-D motional-detection system, determine whether a golfer is applying a positive wrist torque using muscular forces that causes the release of PA#2? That's not possible! I personally believe that PA#2 release in most pro golfers happens passively secondary to the shape of the hand arc and the speed of hand motion along the hand arc path - and nmgolfer has described the mathematical basis of the underlying physics (see nmgolfscience.tripod.com/release.htm ).
BM's claim that "Thanks to some advanced motion-capture technology and biomechanical research from a few very smart guys, we're starting to get a much clearer picture of how elite players produce power, and what you can do to get some more of it" is typical hyperbolic BM-BS! We already understand how elite golfers produce swing power via the sequential release of PA#4 => PA#2.
Jeff.
www.golfdigest.com/golf-instruction/2015-04/3-moves-to-smash-it
Clay Davidson has already commented on the stupidity of BM's reasoning in a Jeffy forum thread - jeffygolf.com/showthread.php?1443-3-Errors-Golf-Digest-Style - but he doesn't go far enough in his criticism.
BM claimed that tour players use those three torques (alpha, beta and gamma) to increase clubhead speed, but I think that it is impossible to significantly increase clubhead speed by using any beta or gamma torque. Gamma torque is simply due to a left forearm supinatory action that happens between P6 and P7, and it is used to square the clubface by impact. However, I know of no mechanism that can allow a "twisting action of the clubshaft around its longitudinal axis" to increase clubhead speed, other than an insignificant amount due to a rotation of the sweetspot around the hosel. The distance between the sweetspot and the hosel is only ~2" and if you multiply that distance by the degrees/second rotation that happens between P6 and P7, then the amount of clubface closing force is negligible (compared to the clubhead speed derived from the sequential release of PA#4 => PA#2).
BM also claims that a clubshaft-shallowing action (torque in the beta plane) increases clubhead speed, but He doesn't explain how that is possible. In his article, BM makes the following three wrongheaded statements-: "In a good downswing, the lower body shifts left and then the upper body turns and pushes into the left arm, which pitches the club into a slightly flatter, more horizontal position. From there, you can turn hard and use the right side of your body to produce extra speed. As your hands move closer to your body near impact, the club whips in line with your left arm—the bit of turbocharging at the bottom that tour players use to get extra distance". How can the upper body turn push into the left arm in such a manner that it causes the clubshaft to shallow-out? How can a golfer use the right side of the body to produce extra CH speed? His 3rd claim that the hands getting closer to the body near impact whips the clubshaft into line with the left arm is a BS-claim! The clubshaft gets into line with the left arm by low point due to the release of PA#2, and not due to any decrease in hub path radius (which can only add a limited element of parametric acceleration in golfers who have a decreasing hub path radius near impact).
I believe that the clubshaft-shallowing action (which happens to variable degree in pro golfers) is due to a variable rate of right arm adduction that happens between P4 and P5.5 and that biomechanically causes the right elbow to drop groundwards faster than the left elbow per unit time.
Consider two examples.
Henrik Stenson
![](http://perfectgolfswingreview.net/StensonHandArcPath.jpg)
The red curved line represents his hand arc path. The straight blue lines are drawn through the two elbows to show their respective degree of downward movement during the early-mid downswing.
Henrik Stenson is an example of a golfer who gets his left arm across his shoulder turn angle at his end-backswing position with his hands very close to the TSP, and who gets his hands/clubshaft down to the elbow plane by the P5.5 position (image 3).
Note that Henrik Stenson's left elbow is slightly higher than his right elbow at the P4 position (image 1).
Note how Henrik Stenson actively adducts his right upper arm at the start of his downswing action (image 2) and note how his right elbow drops slightly more down below the level of his left elbow. It is that differential degree of movement of the right elbow (relative to the left elbow) that causes the clubshaft to shallow-out in his early downswing. Because the degree of dropping of his right elbow (relative to his left elbow) is very small, there is very little clubshaft shallowing-out effect - and his clubshaft plane in his early downswing is only slightly shallower than his clubshaft plane in his late backswing. Note that Henrik Stenson's hands move significantly downwards, and far less outwards (in the direction of the ball-target line), in his early downswing (image 2).
Image 3 shows Henrik Stenson at the P5.5 postion. Note that his hand arc path between P4 and P5.5 is steeper than the clubhead arc path.
Now, consider the hand arc path and clubshaft shallowing-out action of Ryan Moore.
Ryan Moore swing video - www.youtube.com/watch?v=_m3lCmj9yrU
Here are capture images from the swing video.
![](http://perfectgolfswingreview.net/MooreHandArcPath.jpg)
The red curved line represents his hand arc path. The straight blue lines are drawn through the two elbows to show their respective degree of downward movement during the early-mid downswing.
Image 1 shows Ryan Moore at the end-backswing position. Note how steep his left arm is angled with his hands positioned high above his right lateral clavicle area. Note that both elbows are nearly level, with his right elbow slightly higher than his left elbow.
Image 2 shows how actively Ryan Moore adducts his right upper arm in his early downswing and note how that causes his right elbow to drop well below his left elbow. Note how that large differential degree of movement of the right elbow (relative to the left elbow) shallows-out his clubshaft. While that is happening, note that his left forearm must be pronating more so that his intact LAFW can become parallel to a shallower downswing plane, and this left forearm pronation phenomenon happens passively/subconsciously. Note that he maintains an intact LAFW (left arm-clubshaft remain straight-line-aligned) and a GFLW during his clubshaft shallowing-out action. Note that this active right arm adduction motion (that drops the right elbow well below the left elbow) causes the right humerus to become externally rotated. However, note that the right forearm is not affected and it remains neutral. Note that his hands have mainly moved downwards/groundwards and not outwards (in the direction of the ball-target line) - in fact, if you look carefully you will note that his hands have actually moved slightly backwards (away from the ball-target line).
Image 3 shows Ryan Moore at the P5.5 position and he looks very similar to Henrik Stenson at the P5.5 position. If you compare their hand arc paths, they look very similar between P5 and P5.5, but Ryan Moore's hand arc path is much more vertical, and even angled slightly backwards (away from the ball-target line), between P4 and P5. The important golf instructional lesson to be learned from this downswing comparison is that it is very important for a golfer, who has "high hands" at the P4 position (like Ryan Moore), to actively adduct the right arm and drop the right elbow below the left elbow - if he wants to shallow-out the clubshaft (like Ryan Moore). A major swing fault would be to move the hands outwards (in the direction of the ball-target line), rather than primarily downwards, at the start of the downswing as this would predipose to an OTT-move and an out-to-in clubhead swing path during the later downswing. Most importantly, the clubshaft-shallowing action, which affects the plane of the clubshaft in the beta plane, cannot increase clubhead speed. How could it? BM provided "no evidence" to bolster his wrongheaded claim that " a clubshaft-shallowing action" can increase clubhead speed.
Finally, how can PA#2 release (clubshaft motion in the alpha plane) increase clubhead speed? BM wrongly asserts that a golfer has to use a positive wrist torque from an active contraction of left-and-right arm muscles to induce the release of PA#2 (ulnar deviation in the plane of an intact LAFW). He provides "no evidence" to support that claim. He wrongly refers to Steve Nesbit, but SN did not discuss the production of any positive wrist torque in his article - see "Kinematic analysis of the golf swing hub path and its role in golfer/club kinetic transfers" by Steven Nesbit and Ryan McGinnis, which is available as a pdf file at www.jssm.org/vol8/n2/11/v8n2-11pdf.pdf. Steve Nesbit openly states in his hub path paper that one cannot clearly discern what causal "forces" are in play during the club-releasing phenomenon that occurs during phase 2 - when he wrote-: "For all subjects, the initiation of phase II coincided with their first local hub radius minimum, while applying the majority of their respective maximum swing torque, and reaching about half of their respective maximum grip velocity. Acting together these effects increased the centrifugal loading on the club and initiated the rapid outward or uncocking movement of the wrists/club relative to the hub path. During phase II, as the club moved outward, the wrist torques continued to increase accelerating the angular motion of the club. The increase in hub path radius during this phase may be a result of the golfer shifting the effort from controlling the hub path to applying maximum wrist torque, or it could simply be a third-law reaction to the rapid outward movement of the club". In other words, Steve Nesbit is stating that the application of a swing torque that induces the release of PA#4 (release of the left arm which causes the left hand to move along the hand arc path), combined with a "tighter" hand arc path curve during phase 2 of the downswing, causes the club to *centrifugally release. He also states that any increase in hub path radius during the latter part of phase 2 could be due to a third-law reaction to the rapid outward movement of the club and not due to the application of any wrist torque. BM also wrongly infers in his GD-article that he can discern the presence of a positive wrist torquing force phenomenon from the GEARS system when he stated-: "Using the Gears Golf system for tracking body and club movement—the same technology that produced the 3-D swing images in this story—we're able to pinpoint the moves that create those torques and compare them from player to player." How can the GEARS system, which is merely a 3-D motional-detection system, determine whether a golfer is applying a positive wrist torque using muscular forces that causes the release of PA#2? That's not possible! I personally believe that PA#2 release in most pro golfers happens passively secondary to the shape of the hand arc and the speed of hand motion along the hand arc path - and nmgolfer has described the mathematical basis of the underlying physics (see nmgolfscience.tripod.com/release.htm ).
BM's claim that "Thanks to some advanced motion-capture technology and biomechanical research from a few very smart guys, we're starting to get a much clearer picture of how elite players produce power, and what you can do to get some more of it" is typical hyperbolic BM-BS! We already understand how elite golfers produce swing power via the sequential release of PA#4 => PA#2.
Jeff.