Disc Golf Biomechanics

[419HondaGuy]

Excellent read. Thanks for linking that here. Sidenote: article author Kevin Foster is the reason the Jan Zelezny javelin throw gif gets posted here so often.

The notion that there is something fundamentally different going on in a standstill vs. regular throw because of "force couples" and "two feet on the ground" is so silly and ignores the meat for the bones. It even came up in the Overthrow AMA: "I'd love to talk about forced coupling in standstills..."

I agree about loving to chit chat about forced coupling in standstills.

 

[Brychanus]

I agree about loving to chit chat about forced coupling in standstills.

My hypothesis is that some of that concept and language came from golf forms, where in fact some people are fundamentally spin-shifting around a vertical axis to one degree or another rather than "walking it out" in their narrow golf stance.

Corollary: you see variations in shift mechanics even in high level golf, perhaps because you never have to shift the entire body mass very far.

 

[Sheep]

rather than "walking it out" in their narrow golf stance.

You know, this is rarely discussed ever.

The correlation to the swing rotation and hip control to the width of the stance.

Controlling your hips helps control your aim and how you uncoil.

A lot of new golfers wanna look like pro's and they take these huge last steps getting their stance so wide their hips cannot activate, and they end up doing some really interesting things with the upper body as they try and fake a weight shift, pull the disc over muscling and throwing weight.

I honestly need to widen my stance because my hip flexibility is so high its easy for me to over rotate the shot. So I usually stagger really hard.

Maybe were talking about different things, but it was something that qued and I thought about.

 

[Brychanus]

You know, this is rarely discussed ever.

The correlation to the swing rotation and hip control to the width of the stance.

Controlling your hips helps control your aim and how you uncoil.

A lot of new golfers wanna look like pro's and they take these huge last steps getting their stance so wide their hips cannot activate, and they end up doing some really interesting things with the upper body as they try and fake a weight shift, pull the disc over muscling and throwing weight.

I honestly need to widen my stance because my hip flexibility is so high its easy for me to over rotate the shot. So I usually stagger really hard.

Maybe were talking about different things, but it was something that qued and I thought about.

A lot of the narrow stance concepts are in Sidewinder's drill set, then he encourages people to broaden their stances and size of the shift of CoM. Sidewinders core concept is shifting the body mass and weight just like "walking it out."

As you "widen the base" or stance or strides, the form tends to also be getting more horizontal (we can probably think of exceptions, but in general). Spin shifting gets less and less dynamically stable from a balance perspective because of the way legs most easily bear load moving foot to foot in moves like running or walking.

I am looking for examples in narrow stance golf, but I'm pretty sure that you can use a vertical spin shift and still get reasonable club head velocity, and because your feet are relatively in place, you won't necessarily carreen off balance or fall down. That's also why some of the Slingshot style of move can generate a lot of power, but taxes the rear leg significantly due to the way you need to load it to spin shift off of it.

Even when you widen the stance for DG, you can either lead more with your center and redirect the overall body mass, or more emphasize "blocking" your center for forward movement toward the target (reviewing Heimburg wire frame while talking with Chris Taylor comes to mind). You can also find hybrid moves that have a combination of the two, as long as you are not jamming up (I often think about McBeth's evolution from a narrower stance to an incredibly wide and flexible base that still causes dramatic rotational force because of his leverage works from the legs into the hip sockets in posture). I can try to diagram that sometime.

I think we see variations in these even among top players, as long as they are getting foot to foot and fundamentally in athletic balance and posture.

 

[Sheep]

A lot of the narrow stance concepts are in Sidewinder's drill set, then he encourages people to broaden their stances and size of the shift of CoM. Sidewinders core concept is shifting the body mass and weight just like "walking it out."

As you "widen the base" or stance or strides, the form tends to also be getting more horizontal (we can probably think of exceptions, but in general). Spin shifting gets less and less dynamically stable from a balance perspective because of the way legs most easily bear load moving foot to foot in moves like running or walking.

I am looking for examples in narrow stance golf, but I'm pretty sure that you can use a vertical spin shift and still get reasonable club head velocity, and because your feet are relatively in place, you won't necessarily carreen off balance or fall down. That's also why some of the Slingshot style of move can generate a lot of power, but taxes the rear leg significantly due to the way you need to load it to spin shift off of it.

Even when you widen the stance for DG, you can either lead more with your center and redirect the overall body mass, or more emphasize "blocking" your center for forward movement toward the target (reviewing Heimburg wire frame while talking with Chris Taylor comes to mind). You can also find hybrid moves that have a combination of the two, as long as you are not jamming up (I often think about McBeth's evolution from a narrower stance to an incredibly wide and flexible base that still causes dramatic rotational force because of his leverage works from the legs into the hip sockets in posture). I can try to diagram that sometime.

I think we see variations in these even among top players, as long as they are getting foot to foot and fundamentally in athletic balance and posture.

I've never understood spin shifting when you say it.


Our stance is really dependent on our shot, shot shape, shot power. You'd also have to break it down into skill level vs technique as well.

An average golfer is going to want a stance that is repeatable and probably just wider than the shoulders. This allows them to weight shift cleanly and brace without falling over the brace or falling behind the brace.
But instead a lot of newer golfers are trying to run marathons to the brace and their stance falters because they have no baseline where they need to step to carry their weight.

This is why when you get into bigger power shots watching pro's they really stretch out the stance, but its to carry the weight into the brace more balanced.

In perfect theory, I teach using the brace to carry the rotation. The body has to go somewhere, when you brace properly, the body will do what it needs to. So, such for slingshot example, he's weight throwing vs weight shifting. Any time we cheat the chain we build from the brace, we kill whats behind it.

I have a really cool idea how to show everyone in video on this, but it's a bit complex and I need to build a spring to do it.

I have thought of a few teaching aids to demonstrate some of this stuff. But it's just a lot of work to put into building things and just feeling like nobody really cares about the 10 hours you put into something.

 

[Brychanus]

I've never understood spin shifting when you say it.

KISS definition: any time the player is doing any number of unnatural rotational moves that don't function exactly like walking (but sideways-ish in the backhand direction).

This is the same as saying that they are coiling inefficiently and trapping some of their body mass behind the throw.

I would say that "spin shifting" includes a few degrees and kinds of problems, so it's a slightly fuzzy category.

However, there are several symptoms that usually occur together:
1. Spine stays relatively centered and vertical relative to the ground, lumbar doesn't move like walking into the rear coil. This is incomplete "figure 8" action.
2. Rear heel tends to shoot back away from the target and relative to the rear foot toes.
3. Players center of mass/overall mass doesn't really shift much toward target.
4. The are not tilting their balance completely, so the only option is to spin to compensate.
5. Various and numerous compensating mechanics to avoid throwing "over the top" of the plant/brace and not "WTF Richard".

If pictures are worth 1,000 words, videos must be worth 10,000 or more...

In each of these videos are examples of standstill spin shifts vs. "walking" shifts. As usual, thanks to @sidewinder22:



Me vs. him before I completely grinded it out in dingle arm and double dragon. I still feel it happen once in a while and then drill it back out:


Bradley Williams has a high-level throw and PDGA rating, but uses a version of the spin-shift in standstills. Watch closely at his feet and heels, and watch again how trapped his body mass between his legs is in follow through with his body tipping back away onto the rear foot again briefly. He's spinning, not walking:




Notes:
-"Squishing the bug" and forcing the rear leg into internal rotation necessarily are a form of "spin-shift". One visible YouTuber teaches this.
-It's a fuzzy category or continuum - almost every single player I've ever seen, including very far throwers that have passed through here, have some version of these problems still in their form.
-Some people wonder whether this matters performatively. Spin-shifts are far less common in the top PDGA players. Various pieces of spin-shifts have been linked to injury risks in other sports. Anecdotally, most of my spin-shifters report pain in places that are predictable based on how they move.
-Most people IMHO don't really think much about this. Some people "know" the difference intellectually whether or not they can do it in their own movement. Fewer "understand" the difference in their own movement, including people who teach.

 

[Sheep]

Notes:
-"Squishing the bug" and forcing the rear leg into internal rotation necessarily are a form of "spin-shift". One visible YouTuber teaches this.
-It's a fuzzy category or continuum - almost every single player I've ever seen, including very far throwers that have passed through here, have some version of these problems still in their form.
-Some people wonder whether this matters performatively. Spin-shifts are far less common in the top PDGA players. Various pieces of spin-shifts have been linked to injury risks in other sports. Anecdotally, most of my spin-shifters report pain in places that are predictable based on how they move.
-Most people IMHO don't really think much about this. Some people "know" the difference intellectually whether or not they can do it in their own movement. Fewer "understand" the difference in their own movement, including people who teach.

Yeah, saying "spin shift" sounds to me like "throwing weight to initiate rotation."

So, I was reading it right then?

It's tough too, cause there are successful ways to throw discs in a fine manor that work, and its choosing what to teach, what to accept and ... all that jazz.

But. Like I have to teach a homeschool group soon. And. I'm going to honestly teach them spin and throw. Why? It works. Vs spending hours explaining theory to 12 year olds. I can teach them spin and throw and they can have fun THEN with low impact effort that wont hurt them.

Thanks for the clarification. Its really just throwing weight into the brace, vs .. actually bracing and crashing through. And yes, I'd definitely describe a lot of it as ways to hurt yourself.

All these new things out there, its to hard to keep up anymore.

 

[Nick Carroll]

If Corey and Paige do it, that sounds like a good thing to me.

The process as I understand it explained by Sidewinder: Step back, loading on the back leg, turn back while shifting forward, get butt to the target. Then go forward and finish standing up on the front leg. There's no staying on the back leg or spinning the back leg out.

TLDR: Shift forward, spin, then finish on the front leg.

This sound accurate? I want to make sure I understand spin-shifting. It looks really good to me.

 

[Sheep]

If Corey and Paige do it, that sounds like a good thing to me.

The process as I understand it explained by Sidewinder: Step back, loading on the back leg, turn back while shifting forward, get butt to the target. Then go forward and finish standing up on the front leg. There's no staying on the back leg or spinning the back leg out.

TLDR: Shift forward, spin, then finish on the front leg.

This sound accurate? I want to make sure I understand spin-shifting. It looks really good to me.

A proper weight shift will actually induce the spin.

Because you are pushing weight forward then stopping it, well the rest of the body wants to stay in motion, so it tries to pivot around the brace.

We shoudln't call it "spin shift" but "shift spin"
but. ya know.

 

[Brychanus]

If Corey and Paige do it, that sounds like a good thing to me.

The process as I understand it explained by Sidewinder: Step back, loading on the back leg, turn back while shifting forward, get butt to the target. Then go forward and finish standing up on the front leg. There's no staying on the back leg or spinning the back leg out.

TLDR: Shift forward, spin, then finish on the front leg.

This sound accurate? I want to make sure I understand spin-shifting. It looks really good to me.

SW would advise to "walk it out" instead of spin shift. Corey and Paige are doing versions of "walking it out," rather than spin-shifting.

Spin shift is an off balance move trapping the center of mass between the feet.

Walking it out is like what you do walking forward, but sideways or diagonal etc.

My earlier post about golf was that I speculated you see more than one kind of shift even in high-level golfers, in part because both feet start narrow and planted on the ground.

Now that Sheep mentions it you can actually do a spin-shift, where "squishing the bug" is one example, or a shift-spin, which is coming off the rear instep like walking and then spinning when you plant rather than "walking" to lead the throw.

Then you can spin-spin, which is what me vs. Sidewinder or Bradley Williams appear to be doing in the videos above, where you're just spinning around the vertical spine completely. I had to work on the extreme vertical dingle arm for a while to figure out how to fix my balance.

So I guess "spinning" is the broad category, and then there are plenty of specific variants.

Wiggins is walking it out instead. Notice how he gets his leading shoulder and posture down aggressively like a linebacker as he walks it out diagonally:

https://makeagif.com/i/I3jlOa.gif

Resources for walking it out:

Standstill & Figure 8 Motion Pattern

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www.dgcoursereview.com

Had to stare at these wireframe videos dozens of times and compare to my own movement to understand it.

The Hips

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www.dgcoursereview.com

This is fundamentally how you balance to walk, and part of "walking it out". When I work with people they always have trouble getting as deep into the proper balance as Pratt here, and they usually are doing some version of a spin rather than walking it out to compensate. This is also why I suddenly understood the connection between my waltz tilt and X-step in my own movement - same exact idea, just in athletic rather than dance posture.

 

[Sheep]

The amount of ball golf stance/posture video's I've been seeing lately is just blowing my mind with all the neat correlations we are just outright ignoring in disc golf.

 

[Brychanus]

Don't think it's the only way to organize form development, but there is a heck of a lot one can learn from it.

 

[419HondaGuy]

I think this might be worth a read, it's easily applied to DG Form.

Dynamics and Implications of Rotational Energy in Movement

www.just-fly-sports.com

 

[BenjiHeywood]

I think this might be worth a read, it's easily applied to DG Form.

Dynamics and Implications of Rotational Energy in Movement

www.just-fly-sports.com

That's really interesting, and ties in nicely with some stuff I've been thinking about with the 'whip' idea in throwing and how each link in the kinetic chain goes round an arc.

The one thing I'd be tempted to push back on is the 'end range of motion' idea, or at least the implication (whether intended or not) that reaching the limit of motion of one joint is what allows the next bit of the chain to accelerate and overtake. It's probably true in some athletic movements, I'm no expert, but in disc golf at least it's very clear that your joints don't reach their limit before the next bit overtakes.

It's more like a compound pendulum, where even though each joint has a full 360 degrees freedom of rotational movement there can still be significant momentum transfer and acceleration of the next link in the chain.

 

[timothy42b]

That's really interesting, and ties in nicely with some stuff I've been thinking about with the 'whip' idea in throwing and how each link in the kinetic chain goes round an arc.

The one thing I'd be tempted to push back on is the 'end range of motion' idea, or at least the implication (whether intended or not) that reaching the limit of motion of one joint is what allows the next bit of the chain to accelerate and overtake.

I would push back on a lot of it, probably most of it. It may contain useful mental images but a lot of the terminology is at best nonstandard. In particular I don't see how the idea of wave motion adds any information.

Motion only happens when force is applied. Neither energy nor momentum can cause movement. By collision I suppose he means contact, but that isn't true either. Muscles can only contract, so all movement is at some point a pull not a push. And the ground doesn't give you energy; it returns some of what you created through ATP-ADP conversion.

The arc at joints does make sense. Note that the Golden Ratio is an average. Successful athletes differ significantly in those dimensions.

 

[BenjiHeywood]

Yeah, i didn't really understand all that collision stuff but didn't feel qualified to debunk it. I do think that arcs and levers are an easy aspect to overlook, so i guess i made the assumption that some of his other stuff made sense (even though i didn't understand what he was saying in places). Amazing how first impression bias still gets you, even when you know about it.

 

[Sheep]

I think this might be worth a read, it's easily applied to DG Form.

Dynamics and Implications of Rotational Energy in Movement

www.just-fly-sports.com

I want to like this article, but its written so poorly.

Well, Poorly to me. I can't stand this style of writing.

 

[Sheep]

That's really interesting, and ties in nicely with some stuff I've been thinking about with the 'whip' idea in throwing and how each link in the kinetic chain goes round an arc.

The one thing I'd be tempted to push back on is the 'end range of motion' idea, or at least the implication (whether intended or not) that reaching the limit of motion of one joint is what allows the next bit of the chain to accelerate and overtake. It's probably true in some athletic movements, I'm no expert, but in disc golf at least it's very clear that your joints don't reach their limit before the next bit overtakes.

It's more like a compound pendulum, where even though each joint has a full 360 degrees freedom of rotational movement there can still be significant momentum transfer and acceleration of the next link in the chain.

There is some awesome slowmotion in one of these video's where they talk about the physiscs of how the whip works and accelerates itself during the curl motion. blah blah. smart stuff.