Dr. Kwon’s DG 3D motion study

[TractorFox]

Even the Swing Catalyst guys talk about how messy the data is from ball golfers and how changing the same thing for two different players can yield opposite results.

IMO there is an art to the swing.

5 years ago I worked on a project that was trying to analyze walking data and make suggestions to improve efficiency. It produces an insane amount of noise, so much so that comparisons between people was borderline meaningless. Further, you'll hear from informaticians that after introducing 3-4 interacting variables, you start to lose the ability to make relevant inferences. In "The Inner Game of Golf" Gallway talks about how there are thousands of variables to consider with the golf swing, and there are at least that many with disc golf form.

The idea of being recommended form suggestions from inputting a video is cool, but I think people give NNs too much credit and probably not enough for good coaching.

 

[Jaani]

Gallways book was an eye-opener for me and I started to coach with only a few basic ideas, on which the clients can build on.

 

[drk_evns]

The idea of being recommended form suggestions from inputting a video is cool, but I think people give NNs too much credit and probably not enough for good coaching.

Yet.

 

[Brychanus]

5 years ago I worked on a project that was trying to analyze walking data and make suggestions to improve efficiency. It produces an insane amount of noise, so much so that comparisons between people was borderline meaningless. Further, you'll hear from informaticians that after introducing 3-4 interacting variables, you start to lose the ability to make relevant inferences. In "The Inner Game of Golf" Gallway talks about how there are thousands of variables to consider with the golf swing, and there are at least that many with disc golf form.

The idea of being recommended form suggestions from inputting a video is cool, but I think people give NNs too much credit and probably not enough for good coaching.

Yet.

This reminds me of the old debates between Paul Meehl & clinical practioners in the early days before even modest statistical techniques were used in psychology. Meehl (who was very cantankerous, but quite ahead of his time) would point out that people are subject to many heuristics and biases in judgment, and we should use controlled experiments and probability theory to help make choices. He was very aware that part of the reason clinical psychology had a poor reputation is that it was not doing most of the things other sciences were doing. He is a big reason that many of our treatments are much more successful and better-studied today. If you want to read a science classic, here's one of his pieces.

Meehl was trying to solve the first problem - the barest idea that scientific methods could help us do better than people guessing. Right now in psychology & medicine, there is a tremendous call for AI-based techniques to supplement (or indeed, replace) clinicians and clinical judgment. A modern computer can be trained faster and used more cheaply than most clinicians with their six-figure salaries and expensive, decades-long training. FWIW, I'm a big fan of developing these techniques if they are viable. Since I'm in the USA, it's also worth mentioning that insurance companies would love the move, and have teams dedicated to those projects internally. There are political, scientific, and practical issues that have stymied progress there, and the friction between profiteer insurance groups and scientist-clinicians is interesting (and IMO much of it is justified).

Some of the limits to Meehl's own position are still found in AI. A couple of the main problems for AI in those contexts remains (1) deciding which problems to solve and (2) the fit-to-individual problem, which has similar challenges in my areas of study to what TractorFox mentioned. One of the broader debates in NN and similar approaches concerns whether the degrees and kinds of layers and their configurations are sufficient on their own to solve every problem in principle. That is part of the "general AI" problem, where our own brains are often used as a form of gold standard. We're good at many tasks, and increasingly outperformed by AI in narrow tasks (you guessed it - the notion of what comprises a broad or narrow task is also debated). For instance, some of the many things that distinguish brains from most computerized NNs is the huge variety in cells, microstructural connectivity, and internal "computing" functions that have developed within each neuron. This problem is so staggering that you might have seen that some AI scientists are actually coming full circle back to the idea of using human brain tissue ("organoids") to further develop AI. Most neuroscientists aren't surprised by what appears to be an emerging shift in the AI community.

Without organoids, what helps the raw NNs in these contexts is when you provide additional a priori structure and constraints to the issue. If you give an NN more information about the mechanics for the case, it's easier to reduce the search spaces and you end up with fewer instances of spurious associations or getting stuck in bad attractors. That's really hard to do in psychology and many branches of biology. So I can't speak much about biokinetics as a non-expert there. Maybe some aspects biophysical or kinetic sports systems might be a little easier to make NN progress on, and perhaps especially where we already have more information about mechanics to begin with. But for now we still use trained experts mediating between the machine and everything else.

These tensions and debates are how we make progress.

 

[RowingBoats]

I wonder if there would be a way to use pressure plates and audio together in order to provide real-time feedback.

Like that hammer and bell carnival game. Something that audibly records the power/acceleration of the pump. I donno lol.

 

[Brychanus]

Yeah feedback models that track & link improved performance to bio data might be very cool!

 

[timothy42b]

This reminds me of the old debates between Paul Meehl & clinical practioners in the early days before even modest statistical techniques were used in psychology. These tensions and debates are how we make progress.

There's a blast from the past, I had to read him in grad school. He aligns very nicely with Baye's Theorem and the writings of Nassim Taleb (like Black Swan or Fooled by Randomness).

There is a similar debate among musicians between the school of thought that one must focus only on result and avoid focusing on mechanics of embouchure, etc., and those who want to know how it really works. For brass players the first case would be Arnold Jacobs and the second Donald Reinhardt.

The commonality is that the very best musicians often don't know how they really do it and while they think they can teach, they are wrong.

 

[esmeralda]

There's a blast from the past, I had to read him in grad school. He aligns very nicely with Baye's Theorem and the writings of Nassim Taleb (like Black Swan or Fooled by Randomness).

There is a similar debate among musicians between the school of thought that one must focus only on result and avoid focusing on mechanics of embouchure, etc., and those who want to know how it really works. For brass players the first case would be Arnold Jacobs and the second Donald Reinhardt.

The commonality is that the very best musicians often don't know how they really do it and while they think they can teach, they are wrong.

Hello! I have a different take on the matter. I bet that there are also many great musicians who have a deep understanding of the technical aspects of their craft.
And also, I would argue that there are significant differences in their approaches. (I meanw while Baye's Theorem and Taleb's writings emphasize the importance of probability and uncertainty in decision making, the author's work may have a different focus...)
Overall, that's just my thought

 

[timothy42b]

Hello! I have a different take on the matter. I bet that there are also many great musicians who have a deep understanding of the technical aspects of their craft.

Perhaps. But be sure to separate two different aspects of teaching.

A performer - athlete, musician, artist, whatever does not need to know the technical aspects in depth to succeed, and if they were naturals they often don't. (until they get in trouble and don't know how to fix it)

A teacher should ideally have a deep understanding of the mechanics. However, some teachers/coaches are wary of focus on it, and others are the opposite. There are many examples.

 

[Polecat132]

https://www.reddit.com/r/discgolf/comments/13264wo/offarm_mechanics/
Here is an interesting reddit post by coach chris taylor about the off arm. He also talks about pulling with the shoulders/arm to get a deep pocket, which seems to go against what is talked about here

 

[crd 81]

https://www.reddit.com/r/discgolf/comments/13264wo/offarm_mechanics/
Here is an interesting reddit post by coach chris taylor about the off arm. He also talks about pulling with the shoulders/arm to get a deep pocket, which seems to go against what is talked about here

Here are some answers from David Wiggins coach (red font, italics, and bold) responding to people's questions:

jwh777
Thanks for the post. Do you have the rest of this clip? I am curious to see when the shoulders open relative to the hips. I struggle with opening mine too early (I think) and the off arm seems to help anchor the shoulders closed.

motus3d
Yes I have the entire clip, I am David's coach and took this capture. Do not try to 'anchor' or restrict anything in a throw. The synchronization of the upper arm movement vs torso rotation is more of a timing thing. Think about speeding up your upper arm rather than slowing down your shoulders. David's shoulders rotate approx 1000°/sec and his upper arm rotates at 2200°/sec. Practice into a net and focus on upper arm movement and zero shoulder rotation, until you can get deeper into the power pocket.

UnhappyMotor
So if I understood correctly, his arm moves relative to the torso, and the angle is not a constant-ish 90 degrees? If so, this is the pulling motion that I think is nowadays generally advised against, although many coaches seem to recognise that the angle is >90 degrees at release and that some "pulling" can be used to generate power. I believe this is also evident in pro slowmos.

motus3d
Do not listen to 'anti' pullers. His upper arm is rotating more that twice as fast as his shoulders can turn (and his shoulders are rotating at 1000°/sec). The abduction of the upper arm is a true 'pulling' motion (retraction of shoulder blade and then a series of contraction of shoulder horizontal abduction muscles). Do not listen to the lag/slingshot/rubber band crowd.

What's everyone thoughts on what he says?

 

[Brychanus]

https://www.reddit.com/r/discgolf/comments/13264wo/offarm_mechanics/
Here is an interesting reddit post by coach chris taylor about the off arm. He also talks about pulling with the shoulders/arm to get a deep pocket, which seems to go against what is talked about here

Here are some answers from David Wiggins coach (red font, italics, and bold) responding to people's questions:

jwh777
Thanks for the post. Do you have the rest of this clip? I am curious to see when the shoulders open relative to the hips. I struggle with opening mine too early (I think) and the off arm seems to help anchor the shoulders closed.

motus3d
Yes I have the entire clip, I am David's coach and took this capture. Do not try to 'anchor' or restrict anything in a throw. The synchronization of the upper arm movement vs torso rotation is more of a timing thing. Think about speeding up your upper arm rather than slowing down your shoulders. David's shoulders rotate approx 1000°/sec and his upper arm rotates at 2200°/sec. Practice into a net and focus on upper arm movement and zero shoulder rotation, until you can get deeper into the power pocket.

UnhappyMotor
So if I understood correctly, his arm moves relative to the torso, and the angle is not a constant-ish 90 degrees? If so, this is the pulling motion that I think is nowadays generally advised against, although many coaches seem to recognise that the angle is >90 degrees at release and that some "pulling" can be used to generate power. I believe this is also evident in pro slowmos.

motus3d
Do not listen to 'anti' pullers. His upper arm is rotating more that twice as fast as his shoulders can turn (and his shoulders are rotating at 1000°/sec). The abduction of the upper arm is a true 'pulling' motion (retraction of shoulder blade and then a series of contraction of shoulder horizontal abduction muscles). Do not listen to the lag/slingshot/rubber band crowd.

What's everyone thoughts on what he says?

Speaking from the perspective of someone who now finds how people talk about the BH in different ways just as interesting as the mechanics themselves, here are my 2 cents. I'm stepping back to make a few points about how coaches discuss these issues here:

-Everyone seems to have their own views of the mechanics, and even at what level to talk about mechanics (I care about knowing the deepest of the deep levels since I'm an obsessive scientist and find the problems in how to talk about it interesting - not everyone does or even should care, probably). Sometimes the level of mechanical detail varies, and the words used in describing those mechanics are semantically slippery once they're abstracted from the details. E.g. "pull" and "swing are two instances of those abstractions. I'm ignoring the lag/slingshot language for the moment assuming he was talking about SlingShot DG's approach. We can talk about that too of course.

-Different language has different coaching utility to different players. Every player tends to get hung up on words, especially at first, while they're trying to figure form out.

-There is the "timing" perspective (perhaps the majority of DG coaches seem to use this word) and the "rhythm" perspective (people like SW and many golf coaches). "Timing" coaches focus on moments like the plant and when parts of the body do certain things in sequences, often down to millisecond timescales. Rhythm coaches aim to solve timing issue by focusing on a continuous chain of movements framed within anchor points (e.g., the backswing and impact/release etc.). Many coaches use techniques from both of these concepts whether they're using one word or the other or both.

-I think he (Taylor) is right describing the "pulling" motion correctly in terms of the mechanical action and contractions (which is mechanically consistent with swinging the arm from the shoulder pulled taut in the backswing depending on how you want to coach it) but IMHO it is somewhat problematic that he is not mentioning:

-If you are allowing your muscles to be loose and relax and get stretched through the lat and arm against your weight shifting and exploiting stronger contraction after getting stretched out, you might be doing the right thing if your posture is good. Notably, people like Simon explicitly talk about feeling stretched out like a rubber band in the backswing. This is the same way that throwing balls, weights, hammers, swinging bats and clubs far at low effort, etc works. So I personally don't care whether it's called a pull or a swing in that respect as long as your chain is doing the right thing. If you try to pull a lawnmower already muscled through the arm, you will have a more effortful, weaker pull than shifting your weight and allowing the pull/swing of the arm to follow it in sequence letting the arm and shoulder first protract getting pulled taut. The problem with most throwers starting out is that they didn't connect their posture, shift, and "pull/swing" mechanics in the right sequence or are muscled up somewhere too early. If Wiggins is doing the "muscled pull" I used to do I'd be astonished if he threw 600'. If he throws like a baseball player or javeliner, which I think he does, it works as described above. This is one of the concepts many amateurs and especially nonathletes have developing their throws.

I have a mantra for the people trying to improve their actual swings, which is "try it and see what happens" (safely). Do the things that get you closer to The Good Swing. Discard the things that don't.

 

[Brychanus]

*^also need to integrate the concepts like coiling/stretching thru the core staying stretched until you land the shift to lead the shoulder pull/swing/whip/sling/lever/hammerout/redirect (you can see where I'm going with this lol).

 

[semisensei]

I think there are nuggets of truth to be found in all the different descriptions/prescriptions of backhand mechanics. The lag/slingshot/rubber band crowd, and even the spin and throw people - and even the pull with your shoulder person - all touch on important aspects of it, some more than others. It reminds me of the old parable of the three blind men trying to describe an elephant, each touching a different part of it (it's a rope! No it's like a tree! No, more like a wall!). I think many of the online coaches arrogantly attempt to discount all alternative perspectives, to their detriment.
Which is why I'm so excited about Dr. Kwon's study - for the first time, we will get to see some very accurate science applied to many different styles of swings, and we will have some data to really root the conversation. We already have it, really, through correlates with golf and baseball, but it will be awesome to see the data specific to disc golf and all the moving parts of the specific backhand motion.

 

[Kennets]

Chris Taylor always "praised" the "pull", in a "arm needs to swing out/being pulled through faster than the shoulders" kinda way. While he's definitely correct, i still struggle with "how" in my head, lol. I've tried the no rotation, deeper pocket etc, it doesn't just click for me.. throwing a hammer does though. For me, when my chain is right, my arm has no other choice than to sling out, and i wonder if the "arm before shoulders", is merely a byproduct of a good "throw"/chain? Or?

Chris Taylor were really a help for me, when i tried to hit 500 FH, so this ain't a dig at him, merely just me being stupid ar backhand

 

[Sard0nyx]

Chris Taylor always "praised" the "pull", in a "arm needs to swing out/being pulled through faster than the shoulders" kinda way. While he's definitely correct, i still struggle with "how" in my head, lol. I've tried the no rotation, deeper pocket etc, it doesn't just click for me.. throwing a hammer does though. For me, when my chain is right, my arm has no other choice than to sling out, and i wonder if the "arm before shoulders", is merely a byproduct of a good "throw"/chain? Or?

Chris Taylor were really a help for me, when i tried to hit 500 FH, so this ain't a dig at him, merely just me being stupid ar backhand

The arm before shoulders is a part of a good chain. It's really plant, then hips, then torso, then shoulders, then arm. When he says arm before shoulders he means that arm must be moving faster than the shoulders. And really everything in the chain speeds up as it moves from the ground up to your body. Your shoulders have to turn to put speed into the arm, but that isn't the focus. The focus is making your arm move as fast as you can without using the arm.

 

[Brychanus]

In the spirit of trying to tie intercoach threads together I'll keep us rollin' rollin' rollin'

Chris Taylor always "praised" the "pull", in a "arm needs to swing out/being pulled through faster than the shoulders" kinda way. While he's definitely correct, i still struggle with "how" in my head, lol. I've tried the no rotation, deeper pocket etc, it doesn't just click for me.. throwing a hammer does though. For me, when my chain is right, my arm has no other choice than to sling out, and i wonder if the "arm before shoulders", is merely a byproduct of a good "throw"/chain? Or?

Chris Taylor were really a help for me, when i tried to hit 500 FH, so this ain't a dig at him, merely just me being stupid ar backhand

I'm still so interested in BH bc it's such a weird move. So much of "The Good Throw" has to do with getting the body in positions to convert momentum and leverage the ground that someone like me with classic upper body-centric movement & weak lower body has had a really hard time. That's probably why I gravitated toward the body-type-specific very mass and momentum-centered concepts around here. With lots of help, still has taken tons of trying to get my body to land in a way to convert force up the chain rather than force or muscle things. The hammers eventually connected with my martial arts training. The arm/shoulder stuff eventually started to connect with the lower body when I got the chain working on the front leg & I'm still working on getting the rear side to catch up. One wonders what other learning paths I "could" have taken, but progress can happen...

The arm before shoulders is a part of a good chain. It's really plant, then hips, then torso, then shoulders, then arm. When he says arm before shoulders he means that arm must be moving faster than the shoulders. And really everything in the chain speeds up as it moves from the ground up to your body. Your shoulders have to turn to put speed into the arm, but that isn't the focus. The focus is making your arm move as fast as you can without using the arm.

One little thing to add here w/ big consequences that helped me understand optimal lower body & hip action is that we see forces after they have acted. The hips are in continuous motion throughout the move moving from leg to leg. E.g., in my fave angle of Wiggins planting, watch his leading hip. The leg acting on the group is just carrying through the swivel that started as he was moving off the rear leg. Part of how it works is that as soon as his plant toes are hitting the ground, his leg is starting to resist from the calf up and continuing to drive the action through the leading hip socket.

Getting action this clean with posture this good is a huge part of how Wiggins converts nearly every bit of momentum and ground force possible up his chain without destroying his body. This is something that most players just will never quite get to be this clean or this efficient. Look at this - it's pure sports beauty:

IMHO part of the genius of the SW/seabas22 swivel stairs drill is that it can basically teach you exactly how this is supposed to work in the X-step. It can just be really freaking hard to convert that action into the swing moving on flat ground & as you add momentum. Also IMHO one benefit of working with a bit more vertical hop if you've also done a lot of Swivel Stairs - let that gravity and vertical shift help it along.

 

[Kennets]

Thanks for the clarification Sard and brychanus. Form is something that really excites me, not just disc golf wise, but body mechanics in general (martial arts, other sports etc). For me, i think the teach vs feel is different compared to boxing, BJJ, badminton, soccer etc. I've always been quick to adapt to whatever I've done - my FH quickly got to 400+, but despite of having 100 of hours in the field with my BH, I've never really felt comfortable with the throw.

I understand how and why a BH goes far, with what seems like "low effort" and I've had a good amount of throws going way further than what I put in it, i just can't replicate that feeling on a regular basis. I think I'll rewatch that 3d thingy a million time, i might be able to get a "AHA" moment somewhere down the line.

 

[Brychanus]

Thanks for the clarification Sard and brychanus. Form is something that really excites me, not just disc golf wise, but body mechanics in general (martial arts, other sports etc). For me, i think the teach vs feel is different compared to boxing, BJJ, badminton, soccer etc. I've always been quick to adapt to whatever I've done - my FH quickly got to 400+, but despite of having 100 of hours in the field with my BH, I've never really felt comfortable with the throw.

I understand how and why a BH goes far, with what seems like "low effort" and I've had a good amount of throws going way further than what I put in it, i just can't replicate that feeling on a regular basis. I think I'll rewatch that 3d thingy a million time, i might be able to get a "AHA" moment somewhere down the line.

Plenty that gets in the way for many of us. I think for a lot of people getting the whole "surrender yourself to gravity" and "shifting/falling from behind" with your eyes coming off the target is psychologically and maybe physically just plain harder to learn.

Circling a bit back on topic, Wiggins is a great example of using a hop and "freefalling" into the plant to spool up power in his swing. Chris Taylor made some comments about the off arm. Just wanted to add there that Wiggins' off arm looks well in sync counterbalancing his throwing arm and helping him get clearance through the lower body and working with gravity coming in to land on the ground. The muscles are only coming into it to convert force and compound the effect in a beautiful sequence. In my humble opinion/experience it helps to understand how these can work together when building form to minimize the chances that you're overcooking one part of your throw or another.

 

[esmeralda]

In the spirit of trying to tie intercoach threads together I'll keep us rollin' rollin' rollin'

I'm still so interested in BH bc it's such a weird move. So much of "The Good Throw" has to do with getting the body in positions to convert momentum and leverage the ground that someone like me with classic upper body-centric movement & weak lower body has had a really hard time. That's probably why I gravitated toward the body-type-specific very mass and momentum-centered concepts around here. With lots of help, still has taken tons of trying to get my body to land in a way to convert force up the chain rather than force or muscle things. The hammers eventually connected with my martial arts training. The arm/shoulder stuff eventually started to connect with the lower body when I got the chain working on the front leg & I'm still working on getting the rear side to catch up. One wonders what other learning paths I "could" have taken, but progress can happen...




One little thing to add here w/ big consequences that helped me understand optimal lower body & hip action is that we see forces after they have acted. On https://papersowl.com/write-my-essay-please an expert writes my essay. are in continuous motion throughout the move moving from leg to leg. E.g., in my fave angle of Wiggins planting, watch his leading hip. The leg acting on the group is just carrying through the swivel that started as he was moving off the rear leg. Part of how it works is that as soon as his plant toes are hitting the ground, his leg is starting to resist from the calf up and continuing to drive the action through the leading hip socket.

Getting action this clean with posture this good is a huge part of how Wiggins converts nearly every bit of momentum and ground force possible up his chain without destroying his body. This is something that most players just will never quite get to be this clean or this efficient. Look at this - it's pure sports beauty:

IMHO part of the genius of the SW/seabas22 swivel stairs drill is that it can basically teach you exactly how this is supposed to work in the X-step. It can just be really freaking hard to convert that action into the swing moving on flat ground & as you add momentum. Also IMHO one benefit of working with a bit more vertical hop if you've also done a lot of Swivel Stairs - let that gravity and vertical shift help it along.

Can you break down how the hips are involved in translating momentum and ground force up through the body in disc golf, please? I mean could you use Wiggins' form as an example of how it's done right? 'cause I'm still trying to wrap my head around the specifics...