Trail shoulder goes internal?

When I've talked to people who write the code for the systems, they all say shoulders and shoulder blade movements is really hard to measure. So no one has done a great job of presenting quality shoulder data. Also, for me, the purpose of understanding the movements is to understand how they relate to each other. And the shoulder, the scapula, the ribs, and the thoracic spine all work as a unit. So in my head, I'm thinking, if they are asking the shoulder to internally rotate, what are they also asking the scapula, the ribs, and the spine to do at the same time and are they complementary?

So, the one thing that the post says in the text description is, "to look at external/internal rotation (free from its adduction, abduction, protraction, retraction, extension, and flexion)" doesn't really make sense to me as to why you would want to do that. So I'm not convinced by that graphic that they've really shown anything helpful. I think actively trying to internally rotate the trail shoulder at the start of the downswing would hurt most golfers.

Thanks for your insight. Other than to gin up som e interest I don’t really get the point of the clip. I find it hard to believe that they have found some unintended way to accurately measure shoulder movement given what you said about the folks who actually provide the systems. And those angles are really misleading to me - looks more like forearm motion than humerous rotation - which adds to my confusion - especially the amount of angle shown - and a comment about the angle really only being about 30* - well if that is the real amount then why doesn’t the video show it?

As you say, if this leads to folks trying to actively go internal it is going to lead to some poor outcomes. The video evidence is pretty compelling that in good swing the trail shoulder doesn’t move to internal - Looking at p6 and follow thru the elbow - from dtl or fo - doesn’t indicate , to me, an internal rotation since it points toward the body or down at the ground at these times. Now the classic flip/roll to save a shot by using internal shoulder rotation is pretty obvious when it happens and the elbow positions movements are quite different.

I suspect that based on the backswing and individual rom some can add a bit of external in transition and some movement toward internal can be happening but that if the trail shoulder does actually go to internal in good swings then it is very late in swing. It doesn’t look to me like to happens thru release or follow thru but are other body motions disguising it?

If I have things incorrect, I’m interested in learning and welcome the input.

Thanks. Guy

Yes Guy,

I think more important than the amount of movement of internal/external is the intention of the movement and how it would activate different shoulder and core muscle connections. The graphic did make it look like a lot more movement than I would expect to see, so maybe you're right that it was more of a look at pronation/supination.

I think you have a good handle on the concept, now it's just trying to apply it in your own swing!

Happy Golfing,
Tyler

What about the neck? I know tpi discusses importance of neck mobility and strength. Tyler can you describe for a right handed golfer what happens in back swing vs downswing for the neck?

The neck is part of the spine, so it should follow the motion of the spine. The most common time that I coach neck tilts is near impact and into the follow-through (head on a pillow video and idea). Having enough neck tilt can help with the side bend of the spine during the release.

I use neck cues less commonly during the backswing, but similarly, the neck should work with the spine. Occasionally I see golfers tilt the neck too much to the right during the backswing encouraging an upper body sway.

TPI is screening the body for function, and neck strength and mobility play a big role in movement. I see a lot of short backswings as a result of poor neck flexibility, but that's less of a cueing correction and more of a training correction. The downswing is where I see more of the coordination issues of the neck show up.

Hey Guy,

Thanks for sharing. Unfortunately, they didn't really address any of the key questions with that video. We still don't know how they are calculating the different shoulder movements. Their definition of shallow vs steep isn't a metric either. Some golfers have already started steepening by p6, but that didn't mean they didn't shallow during the transition. Or, I often people try and shallow late (after p6) but their definition doesn't really account for that either. So it'll be hard to discuss shallowing, with different definitions of shallowing.

Also, as you mentioned, data on different systems can be calculated differently. Gears seem to have some different patterns of measurement than AMM when it comes to a few parameters (the pelvis and shoulder adduction immediately come to mind). I think gears system has great images, but the data is different than AMM. It's important to recognize that the sensor movement isn't the same thing as joint measurement. There is some direct overlap in movements of the shoulder, so separating ADD/ABD and Internal/External rotation might not be the best for training how the shoulder actually moves.

Lastly, here's one of the more recent videos of Sean (I can't find any of Mike) demonstrating at speed the way they prescribe shallowing. To me, it looks like a fairly steep arm pattern

I'm hopeful that AI might give us better looks at the shoulder than sensors, but right now we have to intuitively look at how the shoulder moves and apply it to the swing :D

Interesting. I note that he appears (don't get to see his setup but his butt moves forward quite a bit from where it starts in the downswing part ) to have a bit of EE involved which might be his late shallow since I don't see any excessive right tilt.

Observed that his elbow is stuck too which explains his release.

I searched a bit and found Bull3D - he has actual graphs of shoulder motion and also claims trail shoulder move internally in downswing. I looked at some of his stuff and it appears he uses something like AMM and certainly not gears based. here is that article from 2020. Again no information on how he is measuring the shoulder.
https://www.bull3dacademy.com/post/shoulder-rotation-what-is-it-really

I think this is just confusing. If I do my swing and do my best to stop when the shaft is shaft align with my lead leg (impact like from "be your own coach overview") I certainly feel my trail shoulder in external and not internal. I don't see how you wipe with an arm moving into internal too - i'd hit it left of left. I'm not changing anything I do based on this. And hopefully not too many folks will "try" to go internal - I do agree that some folks have taken the external move to extremes and tried to really lead with the elbow and end up dropping the shoulder or moving hands out rather than down.

btw I've completed most of the mini courses, and cert 1 & 2 with Dr Kwon. I've been doing steps, pulling bands, swinging rope and using my sheftic board since covid started - what else was there to do. I have not asked him about this video. Maybe someday I'll sign up for your stuff. Only so much stuff i can cram into my brain before it explodes.

Appreciate your input as aways.
Guy

I'd be curious to see more of Mark Bull's data as well. I'm pretty sure he uses a Polhemus system (AMM), which has advantages and drawbacks. Depending on how the system defined top of the swing, I actually wouldn't be that surprised if the shoulder does move toward internal rotation during the downswing. But the only data I've seen was Rob Neal's, and it showed some external rotation for the ones I saw in transition, but he defines top of swing differently than AMM/TPI 3D. You have to know what a system is measuring before making too many concrete conclusions.

If the trail arm does move toward internal rotation, the question would be what is driving it. Is it the shoulder internal rotators, or is it from the scapula or forearm? Is it a compliment to the lead arm motion, or is it an active motion itself?

Most of the muscles that adduct the arm also internally rotate it. If you are trying to adduct the arm while trying to externally rotate it, you might get some internal rotation as well, but both the external rotators and adductors would be active. Again, with the shoulder, some of these blended movements are hard to isolate.

I also agree with your observation, that some people really overdo TRYING to go into external rotation and compromise their spine position as a result. But that's not a problem with going external, that's a problem with not being able to isolate the movements.

Good luck keeping your brain from exploding :)

Tyler

Thanks again. Complex is the shoulder movement. I get the difference between moving internal vs being internal and the timing. And id expect a spectrum of motion versus a bold statement that it (external) just doesn't happen(with the caveat that they haven't seen everyone - likely not matt wolff). I wouldn't be surprised if patterns have folks moving internal after p6 or get internal. Guess it is fuel for internet debate. I know enough to know that i don't know enough.

Guy

I'm digging into it deeper. I found some data from Dr. Rob Neal's system as well as another golf coach who has external rotation built into his AMM parameters. Both of them show the trail arm going into external rotation during transition. So I'm trying to reach out to some people to find out why Gears might be showing a different conclusion. But yes, I think every system shows internal rotation during the release. Anyway, stay tuned!

PS - I'm also trying to get to the bottom of their claim that the trail arm supinates...I've seen LOTS of tour pro pronation/supination graphs and almost all of them pronate during transition.

Happy Golfing,
Tyler

Thank you. I have wondered about what their definition of transition and release is. I know dr kwon determines transition to be part of the backswing and is end of pelvis rotation to end of club rotation - he has his own set of events which do include some of the p system but are much more detailed. I dont recall him having a specific defintion of release but he does focus on the functional swing plane which is essentially p6 thru p8 a d based on the actual measure motionof thE clubhead.

That supination in transition is a good catch - went right past me and ive watched your elite arm swing video probably a half dozen times.

I have also wondered if amg is using some unique software to make thier avatars and do their videos - i dont know if gears supplies this software - make me wonder if they are drawing conclusions from this software and not necessarily gears?

They never supplied numbers in say avg ext in backswing but mention 5* of internal motion in transition and 38* by impact - if these are movement then if the ext is greater than 38* in backswing then the player would still be external at impact Just lots of questions.

Guy

Here's some actual data showing the external rotation from a couple of other systems. I'll discuss this and other issues in the video deeper in my next coaches certification call at the end of the month.

But here's the responses I posted on Facebook:

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A line that Sasho once said to me in response to one of my earlier videos, “it’s easier to pop a balloon than it is to inflate one”. I hope this response is taken positively by Shaun and Mike. Overall, I applaud the quality of the video, and agree with the overall premise that many golfers are overdoing the whole shallowing idea, but I think we could discuss some of the data and conclusions.
External/Internal Rotation:
Here are graphs from a Golf Biodynamics system (Dr. Rob Neal) and a graph from AMM/TPI 3D. Both are of Grant Waite captured at different times. One is a 6 iron and one is a driver. Both systems show an external rotation of the trail shoulder during transition (keep in mind that they define top of swing differently, so the timing is different). The owners of both of these data sets claimed that these are typical patterns of the pros that they’ve collected. Not all externally rotate significantly, some flat line before moving into internal rotation, but only steeper arm motion golfers demonstrated internal rotation during the initial transition.
Now, I’m a little skeptical about the accuracy of the electromagnetic sensors for this measurement, so here’s also a data set from Dr. Kwon’s database of 85 elite golfers, showing external rotation in transition as well.
Collectively, we have 3 other systems showing external rotation in transition (with actual data) as opposed to just a verbal description assuring us that all golfers go into internal rotation.
Perhaps when Mike said in the video that they haven’t measured everyone, what might be more accurate is stating that systems can measure things differently and maybe our data is different than some other systems.
BTW, When I spoke with Rob Neal about his data before this post, he wanted me to stress that he uses the International Society of Biomechanics standard convention for his calculations. The internal rotation is the axial movement of the upper arm compared to the thorax plane.
Perhaps you can explain what convention your system is using to calculate the data and why you think it might be different than these two other large data sets?
Supination/Pronation
I’ve seen many wrist/forearm graphs and almost every tour golfer I’ve seen pronates in transition. Here’s a graph of Grant Waite and Henrik Stenson showing how the trail arm pronates (not supinates) during transition. This too is the normal pattern of the data that I’ve seen related to arm motion during transition. Because supination is relative to the elbow, and influenced by the shoulder movements, I typically saw golfers with supination having much steeper swings than those who had pronation. Dr. Rob Neal said his data showed the same pattern.
Those were the two main issues from the video that I thought would be great to discuss, I look forward to your response.

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I added another point about the elbow separation graph.

Yes, and if recall an earlier video where they discuss the lead arm pulling off the chest in transition (which I recall was more of a calculation decision than an actual fact), that would tend to make the elbows move further away as well. So a few pieces of the shoulder motion in this discussion aren't quite adding up yet.

I hope this helps, thanks for the question!

Thanks. Very interesting. If possible a summary of any resolution from the discussion would be great.

Can i use the dr kwon graph? And share a summary of your discussion points? Also im not in your certification program but it would be great if i could listen in, as a one time thing, to your planned monthly discussion that you mention - if not , i get it.

Thanks again and hopefully the discussion is fruitful.

Guy

Question on dr kwon graph The pattern is er until p2 then ir to the top followed by er until p5 then all ir This is the graph shape but is the starting position really ir and through the swing goes from er to ir etc but the graph would say the shoulder is in ir the entire swing - is this just a calibration issue cause i thought the shoulder can actually get to er - like wrist graphs via hackmotion when it isnt calibrated to neutral but the pattern holds.

I dont understand the first graph with the blacks lines - what is add? Does it say the shoulder moves er then rapidly ir by the top followed by er then ir Confusing to me - is this dr neal's graph The two from grant are pretty clear and i assume are amm/tpi.

Thanks

Hi Guy,

I've been involved in some chats with people from different systems, so here's a quick summary of this video:

The creator of the GEARS system states that his software does not at the moment report internal or external rotation. So the data that the AMG guys are claiming would have had to be written by someone else. I haven't heard them state anywhere who wrote their code or how it was created. The general consensus by those who write the code for the systems is that the shoulders are really difficult to measure, especially when they get above the height of the shoulder. Sasho said that if he had to report in a paper on shoulder movement right now, he's not sure what calculation method he would use.

So it's probably more than just a calibration issue, there's probably a way the data is collected and processed issue as well.

The first graph is a timeline from Dr. Neal's system. Add is address, then top, then impact, then finish.

The Dr. Kwon's graph has been posted in many places at this point, so you're probably okay using it. But if you really want permission, you should ask him personally.

I don't currently have any way to accommodate one time trial listens to the coaches discussions, and I don't have any plans to try and implement something. The coaches program is at a marginally higher price point than the regular yearly membership so I think it's a pretty reasonable way to continue to support my personal research and distribution of my thoughts.

On the Dr. Kwon graph, it's a timeline, just like Dr. Neal's system. The different numbers correspond with different phases, like the P - System. But yes, your summary (pattern is er until p2 then ir to the top followed by er until p5 then all ir) is how it reads. And yes, I think it makes sense to me that it would stay on the internal rotation side of the spectrum. This will likely be wildly different on systems, but Dr. Kwon uses sensors taped to the skin, so it's less likely to have issues than some other systems.

When looking at any pattern, I think knowing the rough range of motion and the timing is enough to help decide what movements are taking place. Like you mentioned with Hackmotion, I don't think you need 100% accuracy to get value from it.

Hope that helps,

Tyler

Tyler,

Thanks for doing the dig. I speculated that amg was using unique software tied to the avatars they produce fir their videos. Maybe mike and sean will engage in a discussion if they havent already and what they are doing will become clearer. Until then it appears safe to say they are the outlier?

I plan to retake dr kwon next certification sessions this spring but afterward i'm likely to do your course.

Thanks much again,
Guy

One more question. They talk about the right arm lifting around 25* Is this something you see in your 3 d data - the trail arm lifts? I can setup, bend my trail arm to somewhere around 90* or less , rotate my arm, and then pivot up to the top without doing any arm lift - at least that i feel - seems to me the lift comes from the right shoulder getting higher since at setup I already have shoulder flexion due to bring bent over. Maybe it is just a feel and the act of bending the trail elbow causes the right arm to lift? Of i ise a line on the elbow plane my elbow stays on it thru the backswing - i would think if i lifted then it would come off, maybe a poor test?

I know deep into the weeds.

Sincerely one of your golf nerd,
Guy

I cant help myself my master's advisor made me review too many computational complexity papers - talk about details being important. I escaped before he pushed me into a phd but he tried.

Hi Guy,

I'm happy to try and get to the bottom of things. It helps me understand and explain better. Unfortunately, Mike and Shaun never responded to my questions, even in the big private group chat. So they appear to have chosen to sit this one out. And yes, their data does appear to be an outlier right now on both the shoulder and forearm movements.

As far as the arm lift, that sounds plausible. AMM has the lead arm lift as a parameter. Golfers typically lift the lead arm 40 degrees or so from set up to the top. 25 sounds reasonable to me for the trail arm. I think in this case, your feeling of no lift might be more of a feel than a real. The arms would be quite flat at the top without any lift.

If a golf nerd can't feel safe here at GSA, then I don't know where they can feel safe ;)

Happy Golfing,

Tyler

Tyler,
Thanks for the effort and the information. Maybe someday it will be resolved.

A follow up on the arm lift spurred by the raise your arms to shallow. Do you have graphs that show this lead arm movement - does it rapidly lower, flatten then lower, etc. is this a real raising relative to the body or a feel? Isit in transition or early downswing - i follow dr kwon definition of transition as end of pelvis rotation to end of club rotation.
And second the general pattern of trail arm elbow extension - does it lose a bit but p5 or stay relatively the same, certain,y starts losing a lot more after delivery position Seems some like nieman really dont lose much then really side bend to get to the ground - i been told chase daniels teaches this plus the lower body move of attempted dual external legs - a quick glance at his instagram and it sure looks like he has some students that do and some that dont.

Thanks again
Guy

Dont know if any if this leads to a new video.

Here's a few of the lead shoulder lift graph. The first three are pros and then the second two are amateurs with more of an arm pull pattern. You'll see some subtle differences.

Wow Very revealing Ams certainly appear to be pulling down from the top.
versus the pros.

Thanks much
Guy

Yes, I always thought the two trends were less pull down from the top and less pull down through impact :)

This motion also seems to go with tour swings, in general, keeping the club close to their body inn the early downswing - if left arm works down early then club tends to move away.

Guy
I'm retaking dr kwon certification this march/April but afterwards I am really going to join your certification. I expect these two will blend together nicely. My wife asks what am I going to do with this - me, I don't know but we'll see, lol.

Question This is shoulder lift not hands lift - where on the shoulder is this lift measured? And is there any way to tell where in the swing a motion point happens - for example, where do the pro graphs like stenson habe the arms start to move down - p5, earlier?

Thanks again.

It's earlier than you think, that's why I think it has to be more of a sequencing issue. The trigger of the downswing. Here's two graphs, one where you can see when the lead arm lowering starts (maybe P4.1). The second graph is just to put in perspective the 3D graphs. About half of the downswing time is done by delivery position (P5.5).

Ah ha Better context. Figures I would need to see a bigger picture to better understand - things like right arm motion, thorax, etc. one body segments motion without context can lead to poor understanding. imagine there is a noticeable difference between pro and ams. One thing I see is pro swings typically keep the club close to the body in the early downswing - much more so than ams. Dr kwon often notes this and the results on angular momentum and ultimately club speed - I see it too as a sign of a more body driven swing - pull hula hoop around you versus down - use the body to throw the arms.

What insights do you have on amateurs lowering arms sooner and more than pros - is this mainly due to pulling the arms in early downswing versus a better use of the body - ultimately a sequencing issue? Me I noticed as I improved my motion and moved toward better body my arms began to feel very passive - with my stall flip I felt arm speed as they swished by my inert turn - as I got steep to shallow, adapted the motorcycle, and extended at the end of my backswing, I was able to rotate better - picked up 30 yards off the tee and just felt like my arms were doing very little. A lot of this was due to you, your book, and this site - so thanks!

Tyler,

Looking to see if I understand the lead arm lift graphs correctly. You said that typical lead arm lift is around 40* from setup - graphs you posted show lift starting in -70 range and going to just above 0 so slightly positive - just say 5-10+ - a total of maybe 80* - I assume this is measured as the arm hangs and doesn't include the preset flexion of the shoulder due to being in forward bend of 35-40* - so if the lead arm goes up 80* but is already at 35-40* at setup then 40* total lift from setup makes sense? Is this correct in that AMM doesn't account for this lift at setup and measures the arm hang?

And I'm seeing the AMs a bit clearer - particularly the second AM that goes way past setup by impact - the pros and the first am appear to either be slightly less or about the same as their setup position - makes sense since shaft is steeper at impact and body would have some lift to accomodate so overall the lead arm would return close to setup - I'm assuming, the second AM though must have some serious EE to account for the additional loss of lift beyond setup - if I EE then I have to lower the arms more (and likely straighten the arms) more than at setup to reach the ball.

Thanks again,
Guy

Yes, on the graphs I posted, the zero line would be the arm at the height of the shoulder. So they start with the arm lower than that, and move towards it (or even past) that height at the top of the swing. Yes, sounds like you've got it. If it starts at 40, and goes to 80, there was 40 degrees of arm lift and the finish position was with the lead arm 10 degrees lower than the shoulder/thorax plane.

So yes, in the am graph that goes way past set up. That golfer usually has early extension and a very pronounced arm pull. Complementary problems that a golfer has to time.

Tyler