AMG - Clubshaft shallowing

[dubiousgolfer]

Dr Mann

I've looked at that AMG video where they showed Phase 1 -3 drills , but I cannot see the shaft shallowing at all (have I missed something?).

Here are the images







DG

[playing18]

I'll wait to hear DG's report from PC. I know what I know and have experienced. This won't change. I don't see any reason to question PC or ML, and others who report/teach this. I know I don't trust what I see visually, especially when both the backswing and downswing side-bend data are provided and are obviously not in conflict with one another. I do appreciate caution and patience when considering a new idea, but I'm quite a bit past that point.

I do concur with ML that a shirt/sweater can bunch up and wrinkle with side bend, as indicated in this video of DJ. To see his sweater response at p4 and p6, you will need to zoom in...and his sweater does do what is expected. But, this is certainly on top of the PC data. Who cares about the sweater response when there is scientific data and it comes from a reliable source. What else do I need? Only to know that both the backswing and downswing data are accurate and both measure the same thing...of the entire torso side-bending, from L5 to C1 as it twists and turns, which I assume it does.




But, as you say about many swing mechanics, it could be optional according to the player. Some pros may swing exactly as you envision. BTW, if you don't mind, DG, perhaps you could ask PC for the standard deviation data, too...this could indicate the range of side-bending or lack of it during the backswing in his data set.

However, I can't accept that any amount of trail side-bending during the backswing is acceptable. Of course, I think pros exhibit about 30-degree of lead side-bend as PC says. If some pros happen to have less or none, fine, but I would imagine they also demonstrate less power due to less dynamic spinal motion.

Finally, I was hoping you would answer the remaining questions I asked. Most importantly, can you see any contraindication for doing a modest amount of lead side-bending during the backswing. I assume there are no reasons not to when it is done modestly (and not to an extreme), and so why shouldn't Milo teach it? Also, I appreciate knowing that club shaft shallowing is a function of arm manipulation, and that pitching the trail elbow is most important. But, if a player is moving from p4 lead side-bend to neutral side-bend at p5, then this could play minor role in club shaft shallowing.

A few minutes ago I just hit balls into a net in my basement. The modest lead side-bending with everything else I'm incorporating feels absolutely fantastic according to this golf addict. 

Jim - playing18

[imperfectgolfer]

Jim,

You posted a video of DJ's golf swing and wrote-: "I do concur with ML that a shirt/sweater can bunch up and wrinkle with side bend, as indicated in this video of DJ. To see his sweater response at p4 and p6, you will need to zoom in...and his sweater does do what is expected."

What is his sweater doing at P4 and P6?

Note that I previously posted a link to this Milo video.

www.instagram.com/reel/CnwufDIoUDN/?igshid=YWJhMjlhZTc%3D

He states that he is going from left bend to right bend.

What do you see that signifies a condition of left bend in that video? How do you define left bend and please explain what I need to see in that video that demonstrates the condition of left bend.

Also, he talks about wrinkles appearing on the right side of Tiger's mid-torso. What is he implying is the cause of those wrinkles appearing?

Jeff.

[dubiousgolfer]

Hi Jim

I think the standard deviation data you wanted to see was previously posted (see below).



DG

[imperfectgolfer]

Jan 25, 2023 20:26:50 GMT -5 dubiousgolfer said:

Dr Mann

I've looked at that AMG video where they showed Phase 1 -3 drills , but I cannot see the shaft shallowing at all (have I missed something?).

Here are the images







DG

I don't know why you cannot see the clubshaft shallowing in those phase 2 images.

Look at the 17:31 minute image (that you presented) where his right hand is at the level of his head and note the clubshaft angle. Then look at the next presented image at 17:33 minute when his right hand has dropped down to the level of his lead shoulder and where his right forearm is slightly more supinated. I think that the clubshaft is slightly shallower in that 2nd image. Watch the video between the 17:43 - 17:46 minute time points and look at those right-sided images. I can see a clubshaft shallowing phenomenon. However, Mike Granato makes a major mistake in those phase 2 images of having the right elbow straightening excessively during his phase 2 demonstration. The right elbow bend angle may go from 90 => 100 degrees between P4 => P5.5, which means that there is only a 10 degree difference.

Try an experiment at home without a golf club. Stand erect (or in a golfing posture) and get your right arm to a shortened P4 position with your right arm abducted and with your right upper arm's rotation being neutral so that your right hand is directly opposite your right shoulder - allowing your upper torso to rotate 90 degrees clockwise by P4. Extend your right wrist so that your right palm is at a ~60 angle to the ground and where a flashlight lying in your palm would point at the ball-target line. Then lower your right upper arm leading with your right elbow and make sure that your right elbow bend angle remains unchanged and make sure that you are simultaneously adducting your right arm towards your right shirt seam. Allow your right forearm to simultaneously supinate a lot. By the time your right arm is adducted against your right shirt seam and where the right hand gets down to the level of your navel your right palm should be more horizontal (= shallower).

I think that it is nonsensical to look for evidence of clubshaft shallowing in those phase 1 images. The clubshaft shallowing phenomenon only happens after the clubshaft bypasses the phase between P4 => P4.75 when the clubhead is looping relatively horizontal to the ground.

Here is Viktor Hovland's clubshaft shallowing images.

If you look at the clubshaft in image 3 it appears to be steeper than the clubshaft in image 2. I ignore those images 1 and 2 when thinking about the phenomenon of clubshaft shallowing and I only consider what is happening between image 3 => image 5.

I agree that they do not demonstrate clubshaft shallowing in their phase 3 images between the 17:53 - 18:04 time point of the video.

Jeff.

[imperfectgolfer]

DG,

I was looking again at this image that you posted.

At P4, is his chest side-bend phenomenon happening perpendicular to the ball-target thereby causing the lead shoulder to become lower.

If correct, then I am using a totally different definition of what is meant by the term "chest side-bend". I am only thinking of left-sided chest bend at P4 being in the coronal plane in a reverse pivoting manner.

Here is an image from the S&T book.

I think that image C and D show left-side chest bend because I am only thinking of side bend in the coronal plane at P4. I am not thinking of side bend of the chest in the sagittal plane at P4 which causes the lead shoulder to get lower to the ground.

I wonder how you and Jim define left-side chest bend at P4.

Jeff.

[dubiousgolfer]

Dr Mann

Yes , now I can see a slight shallowing in those Phase 2 images . But I don't recall AMG mentioning any right arm supination movement in those drills so I suspect Mike Granato didn't recognise that movement in his analysis.

With regards side bend of the chest, yes the side bend would be more in the sagittal plane at P4 then in the coronal. Although I suspect there is also arch extension happening in the frontal/coronal plane in C and D images.

DG


PS. Here is the image on your website, lateral side tilt for images 3  , then I suspect left lateral thoracic flexion happening in image 4 (happening more in the sagittal plane).

[imperfectgolfer]

Jan 26, 2023 9:34:25 GMT -5 dubiousgolfer said:

Dr Mann

Yes , now I can see a slight shallowing in those Phase 2 images . But I don't recall AMG mentioning any right arm supination movement in those drills so I suspect Mike Granato didn't recognise that movement in his analysis.

With regards side bend of the chest, yes the side bend would be more in the sagittal plane at P4 then in the coronal. Although I suspect there is also arch extension happening in the frontal/coronal plane in C and D images.

DG


PS. Here is the image on your website, lateral side tilt for images 3  , then I suspect left lateral thoracic flexion happening in image 4 (happening more in the sagittal plane).

OK - I now think that Milo Lines and Jim George think of left-lateral bend as happening in the sagittal plane during the end-backswing action, which will steepen the shoulder turn angle by P4. It is definitely a major biomechanical feature of the S&T swing technique, but Milo/Jim presumably believe that it is an useful biomechanical phenomenon that can be beneficial for a non-S&T golf swing action.

If Jim can present an argument to explain why it is useful, then I am willing to analyse his argument.

Here is the tilt angle of Stuart Appleby's shoulder turn angle at P4.

Note that his shoulder turn angle is relatively horizontally-aligned at P4.

Now, I can imagine that he could get a steeper shoulder turn angle at P4 by elevating his trail hip joint and by increasing the leftwards tilt of his spine so that his lead shoulder drops more groundwards by P4 due to the acquisition of an increased shoulder tilt angle in the sagittal plane.

However, why would he want to do that if he is not using the S&T golf swing technique?

Jeff.

[imperfectgolfer]

I am trying to reconcile the "evidence" presented by Phil Cheetham versus Rob Neal.

Here is PC's data.

PC states that the average pro golfer has 36 degrees of chest bend tilt at P4 and 31 degrees at impact. Would that not cause the shoulder turn angle to be greater at P4 than P7?

By contrast, in the following video Rob Neal states that the average shoulder turn angle tilt at P4 in pro golfers is 40-42 degrees and that it is 55 degrees at impact.

I can see no leftwards-tilt (groundwards tilt) of the thoracic spine in the sagittal plane in those pro golfers who have a 40-42 degree shoulder turn angle at P4.

How are we supposed to reconcile PC's and RN's acquired data?

Jeff.

[imperfectgolfer]

Here is Milo Lines' latest video on clubshaft shallowing.



He claims that he shallows the clubshaft by going from left side-bend to right side-bend implying that the torso's motion is responsible for clubshaft shallowing and that it is not due to an arm motion.

He also claims that the clubshaft shallowing action is due to the lead upper arm becoming more adducted at the start of his transition. I personally cannot see any clubshaft shallowing happening during his personal golf swing's transition in his video demonstration and I cannot understand why it should happen based on his demonstration.

Phew!

Milo also makes a wild claim that Rory McIlroy adducts the lead arm firmly against his lead upper chest at the start of the transition and keeps it firmly adducted all the way to P5.

Phew!

That's totally untrue.

Here are birds eye view capture images of Rory's early downswing.

The blue circular maker is positioned over his trail shoulder socket and the yellow circular marker is positioned over his lead shoulder socket. An imaginary line drawn between those two markers can give one an idea of the front of his upper anterior chest wall.  Note that there is a ~15 degree angle between his lead arm and the front of his chest wall at P4 and even slightly more at P5. So, I can see no evidence of a tightly-held lead arm adduction phenomenon.

Secondly, how would keeping the lead arm adducted against the upper lead chest wall produce a clubshaft shallowing phenomenon.

Milo also claims that Sergio Garcia is shallowing his clubshaft by using the same lead arm adduction technique and that it is not due to any trail arm lowering/adduction.

Phew!

Consider the evidence.

Note how much SG is lowering his trail elbow by lowering-and-adducting his trail arm between P4 (image 1) and P5 (image 5).

Here are more capture images of Sergio Garcia from a back view that gives one a very good viewing perspective of his clubshaft shallowing action.

Image 1 is at P4. I have drawn a red line under his trail elbow.

Note how much his trail elbow drops groundwards between P4 (image 1) => P4.5 (image 3) during his transition - and I think that it is due to a trail upper arm lowering-and-adduction action where the trail upper arm is being adducted towards his trail side shirt seam.

Note that his lead upper arm is not tightly adducted against his lead upper chest wall at P4, P4.25 and P4.5 and there is a large angle between his lead upper arm and his upper chest wall near his lead armpit. Also, how would a lead upper arm adduction phenomenon at the transition (if it actually happened) cause the lead forearm to pronate, which is a necessary biomechanical phenomenon in a clubshaft shallowing action? 

Jeff.

[playing18]

DG, thanks, I didn't see the SD data in plain sight. It does show some dispersion but it looks like everyone in the sample had some lead side-bend in the backswing and some expressed a lot. This makes sense.

Jeff, I'd don't know how PC and other biomechanists measure side-bend but I don't see why it matters which plane it is measured in since it is relative to the body itself. I'm simple-minded. Spinal side-bend is how much the entire spine side bends or bends laterally from L5 to C1, which is three-dimensional and may be included in all three planes as the spine rotates, flexes/extends, and laterally bends in space at the same time. Whether it is visible on a 2D screen or whether it is obvious as the swing progresses is not important. What matters is the 3D reality of it as you consider its golf swing theory.

But as a non-golf theorist (I'll leave that to you and DG), I'm more interested in golf performance and how I can improve my swing. I know knowledge helps, but the time it takes to figure out the physics and every minute detail is not worth the time. It distracts me from doing what is often much more important...which involves getting good feedback on my current swing faults and doing something about them. I'd rather get tips from Milo Lines and see if his suggestions can help my golf game. And, in a very short time, he and his fantastic website/learning program has given me plenty to work on. This is what I call fun. 

I think one of the advantages of the S&T swing is that it loads the lead foot, tilts or elevates the trail pelvis, and creates lead side-bend in preparation for impact. In theory, this is wonderful for players who have a hard time getting back to the ball and creating a powerful impact position. However, the problem is that it is out of order in terms of generating kinetic force (horizontal, rotational, and vertical force), is not dynamic enough, and it puts the body in a position that requires too much immediate and unnatural pelvic motion (moving from anterior pelvic tilt or curved lumbar spine to posterior pelvic tilt - a flat lumbar spline) in order to get the club to the ball, from p4 to p7. So, for this reason, the S&T method is doomed from the start.

What I've learned from Milo is how to get into a good impact position without taking the S&T short-cut. And, backswing lead side-bend is a part of that. However, Milo does not teach any aspect to the S&T method.

I've always had too much weight on my heels during the swing. An incorrect backswing side-bend was part of that. Milo could have said, you need to swing with more weight on the balls of your feet. Instead, he said, you need to fix your backswing side-bend. I had to figure how to do it, since I'm not taking in-person lessons, but he gave me enough information. I didn't understand the importance of a tilted pelvis in determining spinal side-bend, but now I do. So I now make sure I straighten my trail leg/knee enough on the backswing to get my trail hip elevated and it instantly creates the lead side-bend I need/want. And, of course, this instantly fixed my weight pressure distribution problem...now my weight pressure is on the balls of my feet during the swing which helps to minimize a host of swing faults.

I've already told you enough to justify a modest lead side-bend during the backswing, and the value of Milo's teaching. I could stop here.

I've fought the hanging back and OTT faults for years, despite having a decent game (2-5 handicap). Adding in a modest amount of lead side-bend minimizes these two faults. Starting the downswing with too little lead side-bend means my pelvis and shoulders have been too horizontal. I've always wondered why my lead shoulder would elevate prematurely. Now I know why. Too much trail side-bend, too early. This led to hanging back, and having too much weight pressure on my heels only made things worse. The OTT fault is also part of this fix. The additional lead side-bend creates a different starting position and may help delay early shoulder rotation.

Based on the kinematic sequence, I've readily known that I needed to start the downswing with the lower body with the pelvis activated before the torso, lead arm, and club head. The problem is that kinematic sequence does not incorporate the concepts of the kinetic sequence. The kinematic sequence tells when each tagged part (pelvis, torso/chest/ lead arm, and club head) rotates and how each one accelerates and decelerates. The kinetic sequence, on the other hand, indicates when and how much force is pressed into the ground and when it occurs during the swing.

Of course, I've known the pelvis needed to rotate first at the onset of the downswing, but this has led to much of my OTT problem. Yes, it might rotate to lead off the downswing in terms of rotation (as shown in the kinematic sequence) but that is not what the kinetic sequence teaches a player to do. PGA tour pros demonstrate a specific kinetic sequence and it doesn't begin with rotation, rather it begins with the horizontal expression of force...as Milo teaches. This changed everything for me. The kinetic sequence should be horizontal, rotational, and vertical force expression. The downswing should not begin with rotation per se, it should begin with horizontal or targetward motion that adds to club head speed and happens early (often before p4) and never late...and not after the start of rotational force expression. Just because the kinematic sequence says pelvic rotation happens first (of the four components), it doesn't mean it is the first thing that happens. Horizontal force expression should precede rotational force expression.

So one reason for my OTT move has been applying the kinematic sequence without enough knowledge. A player needs to understand and apply both the kinematic sequence data and the kinetic sequence data, not just one or the other. Having more lead side-bend helps with this as getting farther from the p5 position, gives me more time to apply any horizontal force and delay any rotational force application. Applying rotational force early and fast is a great way to cause the OTT fault. I wish I had known this years ago. 

I've lost some swing speed the past 10 years (63 now), but I'll be getting some of that back I assume. The kinetic sequence also indicates where a player's most force originates in the swing and when. I haven't been on force plates yet, but I'm sure I'm a center or front post player which means most of my force should come from rotation and vertical force expression. My swing speed in my early 40s was about 110 mph and now I'm at 100, but this is about to change I hope. I've been hanging back and haven't been posting on my lead leg for years which means I've been relying too much on horizontal and rotational force with very little vertical force expression (best guess). But, even if my speed only increases a bit, that's okay. Hitting the ball with a loaded lead foot is beyond exhilarating!

A modest amount of backswing lead side-bend potentially helps with the timing of the kinematic and kinetic sequences, but it also requires the spine to move more dynamically and athletically. It creates an increased movement distance for the chest to rotate through from a given p4 chest rotation position. The forward curved spine at p4 must move to a neutral curved spine at p5 instead of remaining "straight" during this time. This can only help with power and club head speed during the important p4 to p5 swing phase. Plus, it is probably good for the spine as it moves dynamically through its normal ROM.

To add in modest lead side-bend during the backswing is an important swing mechanic. Milo is right. Of course, I'm fine to study about it when there's snow on the ground, but it's definitively time to stop and hit some practice balls in my basement.  

Jim - playing18

[playing18]

I hit some practice shots and there's still snow on the ground so I guess I'll take the bait and comment.

Milo didn't say a player couldn't shallow in the way you recommend. He said instructors promote it regularly and didn't condemn anyone for doing so.

Plus, he didn't say a player had do it his way. He was simply analyzing his data base, and providing his best instructional information on shallowing.

I agree with his entire video. He didn't say anything that was not appropriate based on everything he knows and believes in. He certainly didn't say anything that would hurt a player's swing.

My only addition would be to discuss the fall left move (squat move) when the foot pressure is briefly less weighted and when I find it easiest to shallow the shaft. During this brief time, the hands and club are lowering inherently (due to the hip hinge) and a passive lead arm may be adducting (why not?) and the trail elbow may be bending or pitching which is helpful. To me, this is the perfect time to shallow the shaft and the squat move corresponds nicely with the data Milo was discussing. But talking about the squat move too could easily make his video overly complicated and detract from his message.

Milo also talked about the side-bending phenomenon which I completely agree with. This can only help in the club shallowing process. Yes, another benefit of lead or left side-bending in the backswing!

I also appreciate previous discussions and the question DG asked earlier about how many pros shallow the club and does it matter? Turns out it probably doesn't matter that much, assuming the player stays on-plane and he or she has no problem with the OTT fault. 

To me, shallowing is more of a consequence of good, dynamic swing mechanics and it occurs automatically. I'm also fine if a player wants/needs more and pitches the trail elbow to add in even more shallowing, perhaps in an attempt to promote an in-to-ball swing path leading to a draw bias outcome. But, shallowing too much can also be a swing fault.

Jim - playing18

[dubiousgolfer]

I'm confused about the GEARS ribcage side bend values in the video below during early transition and very early downswing.



For SG the ribcage left side bend (ie. negative value) doesn't seem to change by even a degree, so it didn't seem to bounce back towards right lateral side bend.

For Rory , the ribcage side bend seems to increase its negative value by about 4 degrees, so it didn't seem to bounce back towards right lateral side bend.

For DJ , the ribcage side bend also seems to increase its negative value by about 4-5 degrees, so it didn't seem to bounce back towards right lateral side bend.

For Milo, the ribcage side bend negative value decreased from about -37 to -27 degrees , so it seems his ribcage is 'bouncing back'  rightwards.  He does say at 6:15  there is some supination in the trail forearm.

I find GEARS metrics very confusing to decipher (and there isn't much detail to be found on the internet), so does an increase in the negative value of ribcage side bend mean an increase in left lateral flexion?

DG

[dubiousgolfer]

I did not receive a reply to my emails from PC but I've located more information on how Chest Side Bend is measured in this link below.

www.philcheetham.com/two-spine-models-rigid-and-two-segment/

This may sound a bit complicated but essentially one can create a computerised 'local frame of reference' linked to the attached chest sensor. That computer generated 'virtual' local frame of reference will have its origin within the centre of T4 vertebrae.

The same is done for the pelvis so you have 2 computer generated virtual local frames of reference whose movements are compared to a static global frame of reference.

Anyhow to get the correct angles I have included the below extract from the above link.

"The spine angles are relative angles calculated from the thorax with respect to the pelvis. Note that if you try to calculate the spine angle from the difference between the pelvis and thorax angles you may not get exactly the same answer as seen in the graphs above. That is because in 3D when there are three simultaneous angles present they do not simply add up, specific 3D relative joint calculations must be used."


But there is a caveat to all these measurements:

In Figure 4 below, you can see that the thorax (ribcage) and the pelvis are actually modelled as two separate segments capable of independent motion, at least as much as is physically possible. Of course this is still a simplification of true spine motion since the spine has a joint at each vertebra, but at least we can now see how both the global and relative motion of the pelvis and ribcage contribute to the efficiency and power in the swing.



DG

[dubiousgolfer]

Dr Mann

In your previous post you tried to reconcile PC and RN data and said:

"By contrast, in the following video Rob Neal states that the average shoulder turn angle tilt at P4 in pro golfers is 40-42 degrees and that it is 55 degrees at impact."

The 55 degrees is not at impact but seems half way in the follow-through.

DG