Optimising Clubhead Speed - Is this the real way?

[Wildthing]

14 minutes ago, RickyBobby_PR said:

You are still wrong I am only on two forums and rarely post on wrx and I only glance they wrx once or twice a day to see if any interesting threads are new.

So if I’m positing on a forum it’s here. 

You can try to pin someone’s posts on me all you want but it’s not me and will never be me.

 

 

 

 

 

See how you removed any mention of Monte's NTC swing instruction on the ABS forum. 

Edited September 6, 2022 by Wildthing

[RickyBobby_PR]

9 hours ago, Wildthing said:

 

 

See how you removed any mention of Monte's NTC swing instruction on the ABS forum. 

I’ll say this one more time, it’s not me. I don’t even know what ABS is and I have never been on be better golf.

You do realize mgs is a public forum and someone can easily take what I write and copy and paste it elsewhere.

Also I would never use a screen name with bigdaddy in it.

I’m now going to back to not reading posts I have marked as ignored, and won’t be addressing this false claim of me posting or promoting anything on another forum or forums that I have never been on or nor do I care to be on.

 

[Wildthing]

49 minutes ago, RickyBobby_PR said:

I’ll say this one more time, it’s not me. I don’t even know what ABS is and I have never been on be better golf.

You do realize mgs is a public forum and someone can easily take what I write and copy and paste it elsewhere.

Also I would never use a screen name with bigdaddy in it.

I’m now going to back to not reading posts I have marked as ignored, and won’t be addressing this false claim of me posting or promoting anything on another forum or forums that I have never been on or nor do I care to be on.

 

This is what you said in one of your earlier posts:

--------------------------------------

"Imagine if he looked into what the greats like hogan, Snead, Jack, Norman and many others in those eras did that allowed them to be great ball strikers and some of the longest hitters. Or just looked into Bradley Hughes teaching which is based on what those guys did.

Jack said you can’t release early enough, but that also comes with a good turn. Basically the samething Monte and others reach about the trail arm and wrist along with the shifting of pressure into lead leg. All before technology allowed us to see what they did.

----------------------------------

Bradley Hughes is an ABS poster boy.

Bradley Hughes Golf Podcast- John Erickson | Bradley Hughes Golf Podcast (blubrry.net)

Time to ignore your posts from now on.

 

 

[Wildthing]

Confusing information found in 2 research articles by Dr Sasho MacKenzie

Here is Dave Tutelman website link:

https://www.tutelman.com/golf/swing/models3.php

Here is an optimised swing using Dr Mackenzie's model golfer.

Lead forearm rotation torque is the graph  M_Arm and there does seem to be a significant degree of angular impulse (which would be the area under the graph).  Angular impulse will cause a change in the angular momentum of the club but I'm unsure how this impacts clubhead speed.

Here is also a link to a golf research article dated 5th Jan 2012, where Dr MacKenzie is using the same model to investigate the following:

"Club position relative to the golfer’s swing plane meaningfully affects swing dynamics"

(PDF) Club position relative to the golfer's swing plane meaningfully affects swing dynamics (researchgate.net)

In that article he says the following:

"The clubhead speed at impact for Sim3 (44.1 m/s) was 24% higher than that generated during Sim4 (35.5 m/s; Table II). The optimization algorithm found the muscle coordination pattern that resulted in the highest clubhead speed at impact while also ensuring the clubface was square to the target line. The clubhead speed for Sim3 (44.1 m/s) was 22% higher than that generated during Sim1 (36.2 m/s), which indicates as to how much active rotation of the forearm from a muscular torque can contribute to clubhead speed"

Downswing scenarios for SIM1 and SIM3 .

"Sim1 started with the forearm angle set to -10 degrees (Figure 3a), which placed the center of mass of the club 7.3 cm below the golfer’s swing plane (Figure 3b)."

""For both Sim1 and Sim2, the forearm torque generator was set to zero for the entire downswing. In other words, the golfer model was not capable of actively supinating the forearm to square the clubface for impact"

""Simulation 3 (Sim3) was considered the reference condition, as the downswing swing was initiated with the shaft perfectly within the golfer’s swing plane and the optimization was conducted with all the torque generators available to supply energy to the system"

So, the above article, unless I've misinterpreted, seems to infer that active musculature forearm rotation (in this case the lead arm, which is given more torque capability than can be generated by a real human, to complement the missing right arm in the model) can increase clubhead speed by 22% versus a swing that does not use any musculature forearm rotation to square the clubface. 

Now we look at a more recent research article dated 11th June 2019 (or it could be the American date format 6th November 2019). 

http://www.rccssc.ca/pdf/How Golfers Generate Clubhead Speed.pdf

This article 7 yrs after that 1st article above says the following:

Linear Work predicts 90 % of the variability in CHS by itself

Angular Work adds extra 9% (does predict 44% if entered alone first)

 

So, if Linear Work predicts 90% variability in CHS, how can forearm rotation have increased clubhead speed by 22% in the previous research article?  

This seemed very confusing to me, so I looked at the SIM1 and SIM3 graphs

I'm assuming that in SIM3, because the MOI of the 'lead arm/club' unit is smaller about the rotational axis of the torso for a longer period, the 'lead arm/club' unit could therefore be angularly accelerated more by the torso torque generator until the 0.2sec mark  (when the lead wrist starts to unhinge)?  That this increased angular acceleration could account for most of that 22% increase in clubhead speed?

But my assumption above seems to be flawed because when you look at the clubhead speed for both SIM1 and SIM3 they seem to be the same until a point much later in the downswing when the slope of SIM3 graph gets steeper, which suggests a larger increase in clubhead acceleration compared to SIM1.

So, what is causing that steeper clubhead acceleration in the late downswing?  Is it a larger 'In Plane MOF' generated by SIM3 due to a late release & unhinging of the lead wrist or is it caused by an active musculature forearm rotation?

 

 

 

 

 

 

 

 

Edited September 15, 2022 by Wildthing

[Wildthing]

Thought I'd add this useful video on how a biomechanist breaks down the golf swing.   In this case, the golfer wanted an increase in his clubhead speed.

 

[Wildthing]

I was looking at this video (I've attached the .wmv)  on Dave Tutelman's site 

Ben Hogan, Lee Comeaux, and the Right Hand Hit (tutelman.com)

This gives an idea on how fast the wrists can uncock/unhinge using a light short PVC pipe so you can imagine the wrist actions would be somewhat slower if using a golf club such as a driver.  When the club releases due to 'eccentric' forces applied via the grip, the club angularly accelerates at such a rate that your wrists are unable to keep up, therefore they end up applying a negative hand couple at the grip end.

But what about lead forearm rotation when there is an angle between the club and forearm?  Can there still be a positive hand couple torque applied to create cylindrical pendulum motion while there still being a negative hand couple in a double-pendulum type rotation?

Edited October 5, 2022 by Wildthing

[Goober]

It seems like your spinning your wheels young man.Confusion is the main reason for players struggling in this game.My suggestion is study Monty Scheinblumh.He seems to break down the golf swing into manageable parts.Maybe his wisdom might help you get out of your rut. 

[Wildthing]

20 hours ago, Goober said:

It seems like your spinning your wheels young man.Confusion is the main reason for players struggling in this game.My suggestion is study Monty Scheinblumh.He seems to break down the golf swing into manageable parts.Maybe his wisdom might help you get out of your rut. 

Thanks for the suggestion but I find his instruction just an opinion with no evidence to support his theories. Also, what's that got to do with the question I posted?

By the way, his name is Monte Scheinblum , I'm not a young man and not in a rut. 

Rather than looking at 'magic moves' I suggest you invest a fair amount of time reading and trying to understand this article below:

https://perfectgolfswingreview.net/downswing.htm

Edited October 7, 2022 by Wildthing

[Goober]

You can think about the golf swing with or without a club. I think your big holdup is trying to decipher it using both 

[cnosil]

25 minutes ago, Goober said:

You can think about the golf swing with or without a club. I think your big holdup is trying to decipher it using both 

People are different; people learn differently, and sometimes people just want to learn.   @Wildthingis very interested in the physics behind the golf swing and wants to understand the theories behind what people are teaching.   I am the same about all things putting.  I want to understand the stroke, peoples movements patterns, and how the putter itself influences putting.   I like the details about putting and Wildthing likes the details about the full swing.   We just find those details interesting; why is that a bad thing?  Maybe it doesn't help us get better, but maybe that doesn't matter either. 

You talk about Monte's approaches to instruction;  his approach is good for some golfers and not good for others.  This applies to any swing tip or lesson that any person follows.  I could probably point you to instruction that works great for me but is terrible for you.  

[Wildthing]

Interesting video using this Sportsbox AI tool.

Dr Phil Cheetham provides a nice simple explanation on how pelvis lift is being used to increase clubhead speed.

Dana Dahlquist provides some ideas on how to put golfers into various 'buckets' depending on their abilities but imho this AI tool can evolve to do some fantastic things in the future as they collect/load more golf swing data.

https://youtu.be/DRVvE8WiuE8

 

 

Edited October 18, 2022 by Wildthing

[Wildthing]

Some interesting videos by the 'TheSwingEngineer' showing Homer Kelley's Power Accumulator concepts.

https://www.youtube.com/watch?v=kLmovcDc49Q&t=117s

https://www.youtube.com/watch?v=RgJly-Rr2Og

https://www.youtube.com/watch?v=HlXdMW3v0ks

https://www.youtube.com/watch?v=zmNKyiPclkI&t=79s

https://www.youtube.com/watch?v=C9xT71yc8xI

 

 

Edited October 18, 2022 by Wildthing

[Goober]

Can’t go wrong with Homer. I always felt the two essentials were impact and the flying wedge 

[Wildthing]

8 hours ago, Goober said:

Can’t go wrong with Homer. I always felt the two essentials were impact and the flying wedge 

HK seems to have mentioned 3 essentials. 

http://www.theswingengineer.com/essentials.html

Apparently without the 3 essentials you'd have trouble with the imperatives.

http://www.theswingengineer.com/imperatives.html

 

Edited October 19, 2022 by Wildthing

[Wildthing]

The 'Kinetic Sequence' and quite an interesting analysis of the GRFs being used in Justin Rose's swing.

https://swingcatalyst.com/articles/the-kinetic-sequence/

Edited October 19, 2022 by Wildthing

[Wildthing]

Interesting article by MGS.

https://mygolfspy.com/study-accuracy-versus-distance/

 

Here is a conundrum:

Below shows the positions of peak angular speed for pelvis /thorax/arm  in the downswing but compare that to the linear work done 17.4J on the club via the hands for 'peak thorax speed' position.  Doesn't that mean that the body pivot angular rotation hasn't contributed much to the hand forces along the hand path? After that position in the downswing the 'pelvis/thorax' angular rotation is decelerating so it doesn't seem possible they contribute to linear work done on the club via the hands?

 

 

 

Edited June 18, 2023 by Wildthing

[fixyurdivot]

On 8/11/2022 at 6:53 AM, RickyBobby_PR said:

What Monte is doing is exaggerated because that’s one of the best ways to get a movement pattern to change in a person. In his efficient swing video series he has a drill to get to lead arm parallel that has the golfer point the club on a parallel line to the ground. I’m that video he says you will never be in this spot, it’s an exaggeration to get the feeling for how to rotate the arm and be in the right position.

Most good drills are exaggeration because you can’t feel the change without them. But in the swing you wouldn’t be in those positions.

You like a lot of still photos to show certain positions but you never dive into why they are in those positions as it relates to everything else they are doing in their swing or their intent with their swing.

One shouldn’t use DJ as an example For bowed wrists unless they can swing like DJ. Because of his wrist positions his body is going to have to have different tilts than someone else who is less bowed. If they can’t get their hips and body rotating like DJ it’s going to be a disaster.

just like GG says about Matt Wolff’s swing. If one can’t dig and create the forces that Matt does one shouldn’t swing like Matt. Johnny Ruiz who is another GG student saw Matt’s swing and wanted to try it. GG told him go for it. Their two swings look nothing alike because they have the same intent.

This is what understanding the swing is. 
 

With all that said I should have stuck with my previous statement if I’m out, so now I’m out.

The "feel isn't real" resonated with me.  My next investment is likely a session at the local GolfTec.  I need to see my swing mechanics dissected in 3D kinematics. What I think I'm doing to achieve optimal swing motion vs. actual will be enlightening. As has been stated in the prior posts, everyone of us us limitations in how our body allows and does not allow certain motions.  The challenge will be finding an instructor that recognizes this and makes changes accordingly.

[RickyBobby_PR]

2 hours ago, fixyurdivot said:

The "feel isn't real" resonated with me.  My next investment is likely a session at the local GolfTec.  I need to see my swing mechanics dissected in 3D kinematics. What I think I'm doing to achieve optimal swing motion vs. actual will be enlightening. As has been stated in the prior posts, everyone of us us limitations in how our body allows and does not allow certain motions.  The challenge will be finding an instructor that recognizes this and makes changes accordingly.

What I don’t like about golftec is they tend to teach one swing for all. There’s mixed reviews across all the forums on lessons there and I know a few people personally that have had terrible experiences with golftec.

While seeing 3d would be cool all one needs is to find an instructor that works with an individual and what they can do. There are acceptable ranges for all of the positions in golf and one doesn’t have to hit them exactly to play real good golf.

Honestly depending on how much wants to spend there are a handful or so of great instructors online that will be better than an in person lesson and most offer virtual lessons.

Monteu Scheinblum, Henry Fall, Ed Lassiter, Milo Lines, Shauheen N, Eric Cogorno, Dan Carraher would be where I would send anyone looking to improve thru lessons 

[fixyurdivot]

1 hour ago, RickyBobby_PR said:

What I don’t like about golftec is they tend to teach one swing for all. There’s mixed reviews across all the forums on lessons there and I know a few people personally that have had terrible experiences with golftec.

While seeing 3d would be cool all one needs is to find an instructor that works with an individual and what they can do. There are acceptable ranges for all of the positions in golf and one doesn’t have to hit them exactly to play real good golf.

Honestly depending on how much wants to spend there are a handful or so of great instructors online that will be better than an in person lesson and most offer virtual lessons.

Monteu Scheinblum, Henry Fall, Ed Lassiter, Milo Lines, Shauheen N, Eric Cogorno, Dan Carraher would be where I would send anyone looking to improve thru lessons 

I've been warned about that from others.  One thing I'd like to see, and feel would be beneficial to me, is my baseline swing in 3D motion.  Some things for me are easier to understand visually than described.  Coach: "you're starting your front hip move too early", Me: "dang, sure doesn't feel like I am".  I think seeing my swing motions in video form with graphic overlays, for my driver, 6i, and PW would help me make the connection with what is being described as a fault and what I'm feeling... if that makes sense?

I've heard lots of accolades about Monty but not heard of the others you mention; I'll check them out. Thanks 

[Wildthing]

Interesting how hand path could effect the vertical and horizontal components of the clubhead path (SMK is short for Dr Sasho MacKenzie).

 

[Goober]

Deleted. I don’t think my video would pertain to this thread 

Edited August 6, 2023 by Goober

[Wildthing]

It seems that both wrists go through circumduction in the golf swing.

This is a question I posed to Tyler Ferrell :

Because the lead and trail wrists could be gripping the club orthogonal to each other , especially with weak-neutral grips, the relative wrists motions could be quite complex. For example, looking at this slow motion video of Gary Woodland's wrists , it seems that his trail forearm is supinating while his trail wrist ulnar deviates and flexes at the same time (ie. circumduction) just before impact. I'm assuming that his forearm will start pronating through impact. I don't have access to AMM3D kinematic data like yourself but do you see that type of trail wrist pattern in other tour pros with weak-neutral grips? That is, trail forearm supination and wrist circumduction (ulnar deviation & flexion) coupled with lead wrist supination and ulnar deviation (with some extension) from P6-P7?

https://www.youtube.com/watch?v=_QCr-j75SFM

Here was his response:

I think you're assessment from the video is pretty accurate. I've never seen a golfer who didn't pronate just before or just after impact. I'm sure it's possible, but I've never seen it. The trail wrist pattern on the graphs looks somewhat similar for tour pros, even with different grip styles. That's one of the challenges of interpreting the trail wrist graphs.

 

The graphs can be difficult to decipher so here is a summary:

Circumduction

Measurements on the graphs are related to the neutral position of the forearms/wrists. Neutral would be the position of the wrist on the zero horizontal line on the graph below.

 

Blue Graph - is the rotation of the forearm. If above the horizontal line the forearm is in supination, below the line is in pronation.  If the line's slope is positive and moving upwards , that means the forearm is 'rotating' in the supination 'direction'. If the slope is negative and going downwards, that means the forearm is 'rotating' in the pronation 'direction'.

Red Graph: Is ulnar and radial deviation of the wrist.  Above the horizontal line is where the wrist is in ulnar deviation , below the line is in radial deviation. If the line's slope is positive and moving upwards , that means the wrist is moving in the ulnar deviation 'direction' (ie. uncocking the wrist) . If the slope is negative and going downwards, that means the wrist is moving in the radial deviation 'direction' (cocking the wrist).

Green Graph:  Is the flexion and extension of the wrist. Above the horizontal line the wrist is in flexion, below the line is in extension.   If the line's slope is positive and moving upwards, that means the wrist is moving in the flexion 'direction' (ie. wrist moving in the bowing direction) . If the slope is negative and going downwards , that means the wrist is moving in the radial deviation 'direction' (wrist moving in a cupping direction).

Circumduction: Is when the wrist is doing 2 motions at the same time . This could be ulnar deviation direction and flexion direction , radial deviation direction and extension direction.

1.If the lead wrist moves in the ulnar deviation and flexion directions at the same time , it will tend to cause the forearm to supinate. 

2.If the trail wrist moves in the ulnar deviation and flexion directions at the same time , it will tend to cause the forearm to supinate. 

3. If the lead wrist moves in the radial deviation and extension directions at the same time , it will tend to cause the forearm to pronate.

4. If the trail wrist moves in the radial deviation and extension directions at the same time , it will tend to cause the forearm to pronate.

 'Adr' means address , 'Top' is top of backswing,  'Imp' is impact, 'Fin' is Finish.

The vertical axis is measured in degrees , while the horizontal axis is measured time in seconds.

Now that you have the above information , look at the lead and trail graphs for Gary Woodland midway 'Top' and 'imp' . Both forearms are moving in the supination 'direction'. This seems to be happening around P6 (club horizontal) in the downswing even as clubface is being squared for impact by the supination of the lead forearm.

Both wrists are going into circumduction as per points 1 and 2  mentioned at around P6. 

It's only just before impact that the trail forearm moves in the pronation direction (while still in supination at impact)

It's only just before impact the lead wrist starts to move in the extension direction (while still in flexion at impact)

The trail wrist continues to move in the flexion direction all the way through impact (while still in extension at impact).

This just shows how complex the wrist movements are in the golf swing.

 

Here are some more Tyler Ferrell trail wrist graphs showing  5  different hand release styles (I'm still unsure how you would interpret them in a real life golf swing without knowing the angle the lead/trail forearms are making with the ball-target line approaching P7).

 

Edited August 25, 2023 by Wildthing

[Wildthing]

Here is an example of why it is difficult to interpret wrist graphs without knowing the angle the forearms make with the ball target line approaching impact.

Jon Sinclair has a database with 3d data for 100's of golf pros and out of all of them , there is only 1 golfer, Daniel Berger,  who seems to move his lead wrist more in the flexion direction through impact . He thought it was a bug in the 3D system but there does seem to be a possible explanation why the system measured more movement in the flexion direction of the wrist 

Look at the video of Berger's wrists through approaching impact:

https://www.youtube.com/watch?app=desktop&v=4IKdpu5pcm4

DB's lead forearm/wrist  is facing the ball-target line approaching impact, while the tension pull by the club on his hands will be about 100 lb force. Therefore if his lead wrist was in extension because of his very strong grip, its going to be pulled into less extension through impact. 

Without cross-referencing against another graph (or a slow-mo video) showing the angles that the lead/trail forearms are making with the ball-target line approaching impact, it is difficult to make an interpretation of hand release styles just using those AMM3D lead/trail wrist graphs.

 

 

Edited August 25, 2023 by Wildthing

[Wildthing]

Just been looking at Swing Catalyst Video showing Matthew Wolffe.

https://www.youtube.com/watch?v=tXxMcgGrC2g

Some things I couldn't understand in that video at 08:00 - 09:00 

Trail leg twisting action against the ground from P4-P5.  Although the screen image below is not at P4 , one can see that twisting clockwise (from a top down view) of his right foot is in the positive half of the orange Torque graph on the right hand side of the screen.  The 'dot' shows he is applying max torque of 28%  at that moment in time.  

If you look at the orange graph more closely (see image below) , one can see that the torque is still positive from 'Top Of Swing' P4 to maybe P4.5 .  That the right foot twisting clockwise is still happening but is rather small and reducing rapidly.  Previously , I thought the right pelvic lateral rotary muscles would be contracting quite energetically to help rotate the pelvis , but it's small and diminishing rapidly. I estimate that its about 9 lb-ft or 12 Newton Metres at about P4.  

One can imagine what 12 Nm torque might feel like if you straightened out your arm with an apple in your hand (which will cause a torque of approximately 1 Nm).  Now put a sack of 12 apples on your hand and that would be the equivalent of 12 Nm.  But that torque is still quite small if you are trying to twist your whole right leg into external rotation while also trying to rotate your heavy pelvis anticlockwise (from a top view - see image further below).

 

 

So it doesn't seem likely that the above biomechanics is being used to square the hips in the early downswing between P4-P5 .  

Further, look at the orange torque graph of the left leg from P4-P4.5.  

The left leg is also twisting into the ground  in a clockwise direction and actually resisting external rotation of the left leg in the early downswing from P4-P4.5.  This is in tandem with the left leg weight pressure increasing from 61% to 84%. 

I can only assume that Matthew Wolffe must be contracting his adductor muscles as per right image below. The 2  yellow arrow shows what would be happening whereby the pelvis is going to be rotated anticlockwise while the left femur will also tend to be pulled in the internal rotation direction (which would account for the twisting of the left foot clockwise). All of this is only happening in the early downswing from P4-P5.  Other biomechanics and grfs would be taking over as the downswing progresses.

 

Phew !  Trying to understand cause and effect in golf swings is very complicated.

 

Edited August 31, 2023 by Wildthing

[Wildthing]

But now here's another video showing Bryson DeChambeau.

https://www.youtube.com/watch?v=EjzCrs8HePc

At P4-P4.5 , here are his graphs:

 

If you look at the magnified images at P4 and P4.5  and just draw the horizontal components towards/away from the ball-target line , you can see that he seems to be using progressively more push force with his left foot .  Basically , he's pushing into the ground towards the ball-target line more with his left foot than pulling his right foot away from the ball-target line.  The reaction force to his left foot push is that blue vector , while the reaction force to his right foot pull is the red vector.

 

Looks like Bryson is much stronger using his left foot to help create torque in his downswing.

[Wildthing]

Here's some more interesting graphs showing Viktor Hovland's lead wrist kinematics.

 

Viktor Hovland has the lowest 'Rate Of Clubface Closure' on Jon Sinclair's AMM 3D database (look at videos below for more details and explanation of what tour pro wrists do in their golf swings).

https://youtu.be/U6AzuJrZBYM

https://m.facebook.com/LarryRinkerGolf/videos/larry-rinker-golf-live-with-jon-sinclair/581563599454421/

Edited September 5, 2023 by Wildthing

[Goober]

Great analysis of Victor. My body would break in half trying to do that move 

[Wildthing]

 

Post regarding the external/internal rotation of the lead arm

Some graphs showing Dr Sasho MacKenzie golf models .

SMK's 1st Golf Model

If you look at SMK's 1st model, he only allowed rotation of the whole lead arm and no independent rotation of the forearm.

Here is the graph of the optimal swing using his model.

You can see that the arm actually displaced in the internal rotation direction from P4-P5  (ie. went below the zero line) and shallowed the club shaft.

The actual torque applied by the upper arm is shown in the graph below (the bolder dashed line M_Arm)  and it seems to be positive external rotation torque starting at P5.

To summarise:

1. P4-P5 :The golfer model is shallowing the club , therefore the lead arm is internally rotating. 

2. P5-P5.5 :SMK's model does externally rotates about 15 degrees. 

3. P5.5-P7 :SMK's model shows a rapid increase in the rate of lead arm external rotation from 15 degrees to 70 degrees.

 

SMK - 2nd Golfer Model

Here is SMK's 2nd model whose lead upper arm has no ability to externally/internally rotate but does allow forearm supination/pronation.

 

Look at the SIM3 /SIM5 forearm angle and club COM displacement graph's 'a' and 'b' (ie. the bolded line)

 

To summarise:

P4-P5:  There is a slight amount of forearm pronation which is caused by gravity pulling down on the COM of the club. Quoting from the article : "The forearm angle showed a small decrease during the first half of the downswing due to gravity pulling the club below the swing plane".

P5-P6.5 :  There is a gradual supination of the forearm.

P6.5-P7:  There is a rapid supination of the forearm.

So if we looked at the 2  models , there seems to be 2  ways to square the clubface by impact. One just using the upper arm while the other just the forearm.

The only other graph I've seen regarding lead internal/external rotation of the upper arm is this one posted on Mark Bull's website . 

--------------------------------------------------------------------------------------

https://www.bull3dacademy.com/post/shoulder-rotation-what-is-it-really

Lead shoulder

(These patterns and descriptions are for healthy, functioning joint however there are multiple different patterns and values achieved, however it is unusual to see a player achieve a different orientation of the shoulder throughout swing.)

                                 Address                                                                                 Top                      Impact                       Finish

 

Lead shoulder up/down – elevation of the humerus relative to the forward/backward bend of the ribcage.

Lead shoulder abduction/adduction – the horizontal movement of the humerus across and away from the ribcage relative to ribcage rotation.

Lead shoulder external/internal rotation - the external and internal rotation of the humerus relative to the rotation of the ribcage.

Throughout the backswing, relative to the movement of the ribcage the lead shoulder primarily moves through three patterns, internal rotation, adduction and elevation (this is not the shoulder moving up, it’s the humerus/upper arm bone moving up relative to its start position against the ribcage). Therefore at top of backswing the humerus is internally rotated, adducted and elevated relative to the orientation of the ribcage. Observed ranges the shoulder moves through during the backswing and the values observed across healthy, functioning joint are:

Internal rotation from address to top ~ 35°

Adduction from address to top ~ 40°

Humeral elevation from address to top ~ 35°

 

Typical in very powerful players the lead shoulder further adducts as the ribcage rotates clockwise at the start of downswing, with the shoulder also externally rotating and moving down where on impact, it is not unusual to observe the lead shoulder values on impact to be:

External rotation from top to impact ~ 30°

Abduction from top to impact ~ 25°

Humeral depression from top to impact ~ 30°

 

Post impact to finish, this is where the shoulder starts to display the highest rotational value with it moving into significant levels of external rotation, abduction and elevation, ranges achieved can be:

External rotation from impact to finish ~ 60°

Abduction from impact to finish ~ 45°

Humeral elevation from impact to finish ~ 30°

Therefore the shoulder moves through a very defined 4 dimensional pattern (3 orientations over time).

--------------------------------------------------------------------------------

From the available evidence we have, it showed 30 degrees of upper arm external rotation from P4-P7.   But the net effect of the internal  and external rotation of the upper arm from P1-P7  show a slightly larger amount of internal rotation than at address.

 

 

Edited September 7, 2023 by Wildthing

[Wildthing]

Just been looking at the P7.2 images of several golfers .

 

There is a theory that golfers that have a straight aligned arm and clubshaft  at P7.2  are somehow matching the angular velocity of the lead arm and club for a very small time period post impact and are keeping the clubface square to the clubhead path. From a TGM perspective , this would be an intact LAFW and 'Geometrically Flat Left Wrist'. Theoretically, they could be reducing the 'Rate Of Closure' of the clubface to help with their accuracy.

None of this has been proved yet and probably needs more research.

But we know that the angular momentum of the club is pulling the wrists through impact and that the tension in the club is about 100 lb force (ie. the weight of a bag of cement) . The angular velocity of the club is very fast (faster than the wrist can physically keep up),  so how can one get those aligned lead arm and shaft images at P7.2 for Elkington/Olberholser/Charles Howard III ?

From the images above , it almost seems that Elkington/Olberholser/Charles Howard III have more 'lateral side bend' and/or 'trail thoracic flexion' through impact (but only marginally more than Ernie Els- hard to tell).  The exception is Grant Waite who doesn't have as much lateral side bend and whose club shaft has already bypassed his lead arm at P7.2.

I cannot understand from a physics perspective how a golfer can theoretically match the lead arm angular velocity to that of the club shaft from P7-P7.2 .   It could be just a geometric change in the position of the golfers shoulder socket as per below:

 

 

 

 

Edited September 10, 2023 by Wildthing

[fixyurdivot]

This is fun stuff to peruse through.  SMK and others have definitely dissected golf swing kinematics to a level not seen/understood before. This is yet another example of how technology has changed golf and the numerous GOAT and distance discussions that take place. I could see where tour pro's, trying to squeeze out those last few drops of performance, could (and probably do) get overwhelmed with swing thoughts.  

It's also interesting as I suspect 99.9% of golfers are having to overcome their unique physical limitations to make more optimal swing paths.  Much of what we do striking golf balls is anything but natural.