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As you may know I consider Jeffrey Mann to be one of the most knowledgeable people I’ve met when it comes to golf swing mechanics. I have met with Jeffrey at his home twice and once on the driving range before flying out of Salt Lake City where he lives, and I admire his fascination (obsession?) with the workings of the golf swing. Jeffrey is not a good golfer, but he is an ultra-smart guy who has applied his experience as a doctor who cut up cadavers (he knows his muscles, bones, and connective tissues) and as a research analyst for some high -level science publications to figuring out the best way to strike a golf ball. His website (perfectgolfswingreview.net) is quite vast, and some would say it is far too filled with technical terms and far too detailed to be of any practical use. I don’t believe that at all. I think most people are frightened and intimidated by scientific terms and cling to the hope that they can make golf a simple game. Certainly, you can’t be thinking about much when you are playing, but I can’t see how it is detrimental to know how the whole mechanism works.
Anyway, Jeff has produced a 7- hour video series that I have watched (a feat by itself to get through it all but worth the trouble) and since he suggested it I sent him an email with some comments. In the next series of writings and videos I want to share with the members of the site our back and forth. You should really start out by watching Jeff’s videos (you can find them on YouTube or on Jeff’s website), but you can still enjoy our conversation even if you don’t. Let’s begin with my email to Jeff regarding his video series.
“Hey Jeff: If I set up on force plates and my pressure distribution is 50/50, when I load the right leg by pressing down into the right foot does the pressure necessarily have to come by subtracting from the left, or can I maintain my left pressure while increasing the right? In other words, does the pressure number have to equal 100, or can I add pressure by pressing down with both feet but adding pressure to one foot? Am I 80/20 at the top or can I be 80/50?
Also. I like your presentation in general. I have incorporated some of your ideas, as I found them to be better explanations of what was happening, especially with regards to the right hip rotater muscles starting the forward movement as opposed to relating the activity as “pushing” off the ground.
I do find one glaring problem with all of your demonstrations. Of course, Jim has a more supple body and when he is directed by you he does a nice job of moving through the proper positions. However, as you are doing a lot of the demonstrating, I would like to see you pay more attention to two things: one, when you make a backswing turn try to keep your shoulders more angled to the ground. You set up in fine posture but by the time you are looking back at the camera and talking about what happens approaching the top and in transition your right elbow is significantly lower than your left, and your shoulders are almost horizontal to the ground. When you watch most great ball strikers the right elbow is almost always even with or above the level of the left elbow at P.3. I can assure you that the downswing you demonstrate cannot be achieved from that backswing position. You are already losing spine angle and if the right arm adducts with any aggressiveness the shaft will shallow to a plane that is far too flat. The pelvis has already leveled and the prospect of anterior tilt in transition is slim. You should try your best to turn your upper trunk closer to the angle of your spine at address. Your shoulders should be much more tilted when you show a top of the swing position.
In video #6 at 2:32 your demonstration shows a shaft that has shallowed under the plane in the downswing at about P 5.6. You will note that most great ball strikers shallow the shaft early in transition and for a short period of time (during the period between 3.8 and 4.5) and then complete the forward swing to impact by gradually steepening the shaft. This brings the shaft down above or directly on top of the right forearm, not under it as you demonstrate. The item that is the primary causal effect in all of this is your lack of pelvic rotation in your demonstration. At P 5.4 your hips are well closed, your left leg completely in view. There is no way the shaft will be pulled around effectively with that amount of hip rotation. I am suggesting that in your demonstrations you make sure that the pivot is always pulling the left arm. You do way too many things with just your arms moving and not your pivot. I believe it is vitally important to demonstrate accurately. It was a very good idea to get Jim to help you. But you do a lot of demonstrating and you would be more effective if you focused on more on the form while you were delivering the message.
Wayne D.
Here is Jeffrey’s reply:
Wayne,
The COP measurements are always expressed as percentage of the total COP, and they do not reflect “absolute” values in terms of measured vertical forces. They therefore must always add up to 100%, and it is impossible to get a reading of 80:50 for example.
Although your criticism of my demonstrated pivot motion is correct, you seemingly do not understand that I cannot demonstrate the “correct” body motions – as I have repeatedly explained in my previous video projects. I never even attempt to make the correct pelvic or upper torso rotational motions, and I only demonstrate with my arms/clubshaft. I have always pre-warned viewers of my videos to never look at what I am doing, and I have always stated that they should only listen to what I am saying – when I talk about a specific golf instructional point. The only reason why I undertook this latest video project was because I could use a model golfer (Jim George) to visually demonstrate the swing principles that I discuss. When I am talking alone (which is most of the time), the viewer needs to understand that he must only listen to what I am saying, and he must not watch what I am doing in terms of body movements.
You wrote-: “In video #6 at 2:32 your demonstration shows a shaft that has shallowed under the plane in the downswing at about P 5.6. You will note that most great ball strikers shallow the shaft early in transition and for a short period of time (during the period between 3.8 and 4.5) and then complete the forward swing to impact by gradually steepening the shaft. This brings the shaft down above or directly on top of the right forearm, not under it as you demonstrate.
I totally disagree with your expressed opinion – if the golfer maintains an “on-plane” clubshaft throughout the entire downswing (like Adam Scott, Henrik Stenson, Justin Rose and Rory McIlroy) and if he does not perform a “tumble action” – see this short review paper at http://perfectgolfswingreview.net/VP7.html. Also, note that the clubshaft must drop down below the plane of the right forearm if the clubshaft ends up on a plane (between P6 and P7) that is below the elbow plane eg. hand plane.
Here is a video showing that Hogan’s clubshaft drops down to a shallower plane than the elbow plane between P5.5 and P7 –
By contrast, if those golfers were shallowing the clubshaft in the early downswing (like Sergio Garcia) then your described “shallowing => steepening” phenomenon would happen because Sergio Garcia’s clubshaft is off-plane (with the butt end of the clubshaft pointing outside the ball-target line) in the early downswing (between P4 and P5) and he then has to perform a “tumble action” in order to steepen his clubshaft between P5 and P6 so that he can get the clubshaft back “on-plane”. However, I think that the “shallowing => steepening” phenomenon (which is seen in Sergio Garcia’s downswing) is atypical, and it is not seen in golfers (like Adam Scott) who keep their clubshaft continuously on-plane” throughout their entire downswing.
Jeff.
Now here is my reply:
Hey Jeff: I was merely suggesting that you might make the attempt to keep your shoulders more tilted even though your swing would be much shorter. As for your example of Hogan, the camera is well above him which distorts the appearance of how the shaft approaches from P5 to P6.5. In the videos of Hogan that are properly filmed (there aren’t many) he flattens the shaft well above the ball target line at P4.5 and approaches with the shaft on or above the right forearm at P5.5, which would indicate that he is already in the process of supinating the left forearm and bowing the left wrist ( which I think you refer to as a “tumbling” action).
I have a question for you: do you think that strengthening the left hand grip happens by pronating the left forearm or by dorsiflexing the left wrist? I find that if the club is placed near the bottom of the fingers running diagonally across the first segment of the index finger that by keeping the radius bone more directly over top of the ulna the grip stays in the same place across the hand and the pinky and ring fingers have more gripping power by virtue of the finger joints being able to curl around the club and squeeze. If I push the vertically aligned wrist inward before squeezing I can see more knuckles and the palm turns more toward the ground. If the grip is strengthened by pronating the forearm the grip moves further up into the palm where the last two fingers have much less gripping power. If you look at the grips of various professionals you will see both types, but I think that the more vertically aligned wrist that is pushed inward is more common (see Dustin Johnson and Steve Elkington among others). Interested to hear your thoughts.
WD
And here is Jeff’s comeback to that:
Wayne,
You wrote-: “As for your example of Hogan, the camera is well above him which distorts the appearance of how the shaft approaches from P5 to P6.5. In the videos of Hogan that are properly filmed (there aren’t many) he flattens the shaft well above the ball target line at P4.5 and approaches with the shaft on or above the right forearm at P5.5, which would indicate that he is already in the process of supinating the left forearm and bowing the left wrist ( which I think you refer to as a “tumbling” action)”.
You are seemingly claiming that Hogan shallowed his clubshaft between P4 and P4.5, so that his clubshft is off-plane at P4.5 (with the butt end of the club pointing well outside the ball-target line). I have never seen a video of Hogan where he performs that off-plane clubshaft motion. Can you please send me a link to a video or capture image showing an off-plane clubshaft? I also do not believe that Hogan was supinating his left forearm between P4.5 and P5.5. Can you send me “evidence” to support your “belief” that he was supinating his left forearm during that time period. I certainly do agree that Hogan probably used the “early left forearm supination + left wrist palmar flexion” technique, but that only happens between P5.5 and P6.5 – see topic number 1 in the appendix section of this review paper – http://perfectgolfswingreview.net/chamblee.html
Also, look at Hogan performing his “early left forearm supination + left wrist palmar flexion” technique in this animated gif –
If you do not think that Hogan’s clubshaft is shallower than his right forearm in image 2, then we perceive reality very differently.
You asked-: “I have a question for you: do you think that strengthening the left hand grip happens by pronating the left forearm or by dorsiflexing the left wrist?”
It must happen secondary to pronating the left forearm. However, that left forearm pronatory action angles the left palm to the right, so that if a golfer grips the club correctly with the left 3rd, 4th fingers and 5th fingers firmly clenching the grip, then the club has to be angled backwards away from the target (mimicing forward shaft lean). Some golfers make the mistake of trying to adopt a stronger left hand grip while keeping the left arm and clubshaft perpendicular to the ball-target line, but then they will not be gripping the club correctly with the left 3rd, 4th and 5th fingers and their left hand grip will likely be too “loose” with the club handle probably riding too high up into their palm area (which means that they have probably unconsciously/unintentionally converted from using a low palmar left hand grip to a mid-palmar left hand grip).
Here is an image of Dustin Johnson at address and at impact.
Image 1 shows Dustin Johnson at address. He uses a moderately strong (3 knuckle) left hand grip. Note that his hands are ahead of the clubhead and that means that he has forward shaft lean. Note that the lifeline of his left palm must be angled back away from the target when he adopts a stronger left hand grip – due to the fact that he pronated his left forearm before gripping the club handle. Note that his left wrist appears very dorsiflexed, and that is a natural end-result of adopting a stronger left hand grip if you keep the clubshaft straight line-aligned with the left arm.
Here are images of Keegan Bradley at address and at impact.
He also uses a moderately strong left hand grip. However, he prefers to stand at address with his clubshaft being perpendicular to the ball-target (rather than having forward shaft lean like Dustin Johnson), which means that he has to bend his left wrist. That additional left hand bending action makes the back of the left hand appear to be even more dorsiflexed.
Jeff.
At this point I figured it would be a good idea to send Jeff a video to clarify what I was talking about pertaining to Hogan’s shaft shallowing move:
Wayne,
Thank you for taking the time to produce that video on Ben Hogan’s shallowing action.
I will provide feedback in the form of a commentary paper, which I will soon write. It may take me a few weeks because I have to produce a lot of capture images.
Two preliminary questions.
Question 1:
See attached jpg.
Image 1 shows Hogan at P4 and you measured a clubshaft angle of 60 degrees.
Image 2 is at P4.8 and you measured a clubshaft angle of 40 degrees.
Those drawn red lines suggests that Hogan shallowed his clubshaft angle by 20 degrees between P4 and P4.8. Do you believe that the 20 degree difference is a reasonably accurate reflection of the degree of clubshaft shallowing to an off-plane position?
Question 2:
What biomechanical movements does Hogan use to causally produce that clubshaft shallowing action?
Jeff.
Wayne,
I have completed part 1 of my commentary on the topic of “clubshaft shallowing” between P4 and P4.8.
See – http://perfectgolfswingreview.net/waynecommentary1.html
I am open to any criticism or disagreements that you may have with respect to my personal thinking on this subject. I am always willing to revise my thinking on issues related to golf swing biomechanics/mechanics if I can discover a better way of thinking about any of the issues.
I can also produce more commentary parts if your are interested.
Jeff
I will print out Jeff’s commentary paper:
Commentary on Wayne’s analysis of Ben Hogan’s clubshaft shallowing move – Part 1
Wayne,
You made the following comment in a previous e-mail message-: “You will note that most great ball strikers shallow the shaft early in transition and for a short period of time (during the period between 3.8 and 4.5) and then complete the forward swing to impact by gradually steepening the shaft.”
You then attempted to demonstrate that phenomenon in your video analysis of Ben Hogan’s golf swing.
In your description of the clubshaft shallowing move, you seem to be implying that the clubshaft becomes off-plane during the early downswing (so that an imaginary line extending out from the butt end of the club points outside the ball-target line), and that it then becomes on-plane again in the mid-downswing as the golfer subsequently steepens the clubshaft. Although I can agree with you that your described phenomenon happens in a small subset of PGA tour golfers, I think that the majority of PGA tour golfers can shallow the clubshaft during the early downswing while remaining on-plane. I would imagine that you will immediately disagree with my last claim because your definition of a clubshaft shallowing action is a situation where an imaginary line extending out from the butt end of the club points outside the ball-target line, which means that it is off-plane (and not on-plane). Before I analyse your description of a clubshaft shallowing action, note that my personal definition of a clubshaft shallowing action relates the motion of the clubshaft relative to the hand arc path, and I believe that the clubshaft shallowing action can be an on-plane phenomenon, or an off-plane phenomenon (if the degree of clubshaft shallowing happening per unit time is greater than the amount needed to still maintain an on-plane clubshaft). See this short review paper – http://perfectgolfswingreview.net/VP6.html – where I describe how, and why, many pro golfers shallow their clubshaft during their early-mid downswing. I use a number of pro golfers as examples, and they all shallow the clubshaft between P4 and P5 (relative to their hand arc path), but they all keep the clubshaft on-plane during their clubshaft-shallowing action. You do not use the hand arc path as the reference point for definining a clubshaft-shallowing action, and you base it on lines drawn down the length of the clubshaft, while noting two points – i) that the clubshaft angle changes (shallows) between P4 and P4.8 and ii) a line drawn out from the butt end of the clubshaft at P4.8 will seemingly strike the ground at a point outside the ball-target line.
So, let’s consider your video analysis of Ben Hogan’s swing.
Here are capture images from your video.
Image 1 represents the P4 position, and you have drawn a red line from the butt end of the club to the ball. That line measures 60 degrees. That line goes just below Hogan’s right shoulder, which means that his hands are on a plane that is slightly shallower than the TSP. By drawing that red line in that way, you seem to be implying that the butt end of his clubshaft is pointing at the ball, but that is not possible (even if the clubshaft is on-plane) because it must be pointing far more backwards towards a point on the ball-target line (presuming that it is on-plane) that is many yards further away from the target.
Image 2 is at P4.8. You have drawn a line down the length of his clubshaft and extended that line outwards. That line measures 40 degrees. You have then seemingly concluded that Hogan has shallowed his clubshaft by 20 degrees between P4 and P4.8. Because that projected line points outside the ball-target line, you have also seemingly concluded that the clubshaft shallowing action (of 20 degrees) causes the clubshaft to become off-plane. I believe that both conclusions are scientifically invalid. I think that your fundamental mistake is that you are willing to draw those lines on a 2-D image when the clubshaft is not parallel to the camera lens, and that you are wrongly concluding that those red lines accurately reflect where the butt end of the club is really pointing. I believe that it is not possible!
I believe that those drawn red lines can only be accurately reflective of reality when the clubshaft is parallel to the camera lens – as seen in image 3. Between P4.8 to P5.2, the clubshaft is either parallel to the camera lens, or close to being parallel, and therefore drawing a line outwards from the butt end of the club in the direction of the ground can accurately reflect reality. Note that the white line (drawn down the length of the clubshaft) in image 3 points at the ball-target line, which means that the clubshaft is on-plane.
Also, to prove my point that a 20 degree change in clubshaft angle between P4 and P4.8 doesn’t automatically imply that the clubshaft is shallowing – consider the following presentation.
Video of a golf robot –Here are capture images of the golf robot performing a driver swing.
I have labelled each image with two pieces of information – i) the P position, and ii) the angle of the clubshaft.
I presume that you agree with two points – i) that the golf robot has a single plane golf swing (zero-plane shift golf swing) with no clubshaft shallowing action and ii) the clubshaft is always on-plane (which means that the end of the club that is nearest the ground will always be pointing at the ball-target line – when the clubshaft is not momentarily parallel to the ball-target line).
Now, can we draw lines outwards from the end of the club (that is nearest the ground) and look to see whether it points at the ball-target line – thereby signifying an on-plane clubshaft? I believe that it only possible when the clubshaft is roughly parallel to the camera lens, which usually happens at ~P5 and at P7. Note that the measured clubshaft angle is identical (52 degrees) in both those P5 and P7 images. Note that the clubshaft angle of 51 degrees at P5.5 is close to the 52 degree angle, which is not surprising if the clubshaft is not shifting planes and if the club lag angle has not changed much between P5 and P5.5.
Now, consider an interesting fact – that the clubshaft angle changes by ~13 degrees (in a shallowing direction) between P4 (where it measures 70 degrees) and P4.7 (where it measures 57 degrees). We know that the clubshaft is not really shallowing between P4 and P4.7 and that it is always on-plane (on a fixed plane), so what accounts for the 13 degree of “apparent” clubshaft shallowing?
I think that the changing angles only reflect the fact that the clubshaft angle (as viewed from a DTL perspective) is obviously changing between P4 and P4.7 because the central arm (equivalent to the left arm) is moving downplane, which means that the clubshaft is also moving downplane in 3-D space. None of those angles reflect reality (indicating where the clubshaft is really pointing in that 2-D image) because the clubshaft is not parallel to the camera lens. Note that the angles are moving in the general direction of 52 degrees (where the on-plane clubshaft is parallel to the camera lens), which is in a shallowing angle direction – but those progressively shallowing angles does not mean that the clubshaft is actually shallowing out (because clubshaft shallowing is physically impossible in the golf robot’s single-plane golf swing action).
Why are the 70 degrees and 57 degree angles different to Hogan’s swing? That is not surprising because Hogan’s left arm is much shallower than the Golf Robot’s central arm (left arm) at P4 and at P4.7.
Consider this photoshopped image.
I used Photoshop to superimpose a copy of the P4.7 image on top of the P4 image, and I then used the free transform tool to tilt the central arm groundwards to a slightly shallower plane. That will obviously shallow the clubshaft angle (which now measures 40 degrees and not 57 degrees), and a line extended out from the butt end of the club will also move more outwards (to beyond the ball-target line). That line cannot actually reflect the “true life” reality of where the clubshaft is really pointing because the clubshaft is angled away from the plane of the front of the camera lens. The only point that I am trying to make is that one could design a golf robot where the plane of the central arm’s zero-plane shift motion is on a shallower plane, which will cause the 70 degree angle at P4 to measure closer to 60 degrees, and the 57 degree angle at P4.7 to measure closer to 40 degrees. Would that cause the shallowing-difference of 13 degrees to become greater, and closer to 20 degrees? It may, and it would not surpise me if that happended. In other words, it is possible that the 20 degree angular difference between Hogan’s P4 and P4.8 clubshaft angles may have nothing to do with any “real life” clubshaft shallowing action that can potentially move the clubshaft off-plane. The burden on you is to prove that some fraction of that 20 degree angular change between P4 and P4.8 in Hogan’s swing is truly due to a “real life” clubshaft shallowing phenomenon that really moves the clubshaft off-plane.
You also have to make more sense regarding those lines drawn out from the end of the club that is nearest the ground.
Consider this composite capture image from the Golf Robot video.
Image 1 is at P4. Note that the blue line drawn out from the clubshaft seems to hit the ground well inside the ball-target line. That’s obviously an “artifact” due to the fact that the clubshaft is not angled parallel to the camera lens, and we know that the imaginary line must really be pointing at the ball-target line because the clubshaft is always on-plane.
Image 2 is at P4.7. Now, the blue line is moving in the direction of the ball-target line, which is not surprising because the clubshaft is 13 degrees shallower at P4.7 compared to P4. That blue line still cannot reflect “true life” reality because the clubshaft is not parallel to the front of the camera lens, and we know that the imaginary line must really be pointing at the ball-target line because the clubshaft is always on-plane.
Using your technique of drawing lines outwards from the butt end of the club (when the clubshaft is not parallel to the camera lens) is a very unscientific technique that is very problematic in terms of representing “true life” reality. I think that you need to solve this problem, and I am very open to analysing any of your further suggestions and any other feedback (if you disagree with any of the points in my presentation).
Finally, have you ever traced Ben Hogan’s hand arc path to see how his clubshaft shallows-out relative to his hand arc path.
Here is an example.
The red splined path represents his hand arc path. His left arm is at the P4.8 position. Note the small degree of clubshaft shallowing that exists relative to the hand arc path.
Where do you think that an imaginary line extending out from the butt end of his club is pointing? I personally suspect that the imaginary line is pointing in the direction of the ball-target line and that his clubshaft is on-plane at P4.8 in that particular swing action.
Jeff.
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