New disc golfers usually throw a disc using their shoulder almost exclusively. But it is the rapid(!) extension of the elbow which provides the majority of distance in a backhand throw. Today, Vortica examines the elbow and the arm, how best to use them, and expands on a new concept in the Disc Golf lexicon; the Plane Of Play.

Throwing a disc accurately and efficiently requires a disc be pulled along a straight line (The Line Of Play) and accelerated along that straight line, by a set of levers working on a plane - the Plane Of Play.

The Plane Of Play is created by the shoulder socket,

elbow hinge, wrist joint, hand, and disc.

The Line Of Play and the Plane Of Play are connected by the hand gripping the disc. Additionally, the Plane Of Play must be aligned parallel with the Line Of Play, rather than intersecting it via the grip. The Line of Play is created ON the Plane Of Play.

In 3D space, a line is defined as the intersection of two planes

Original image credit: http://www.frisbee.net/index.php?showimage=1565

Figure 1. Paul McBeth demonstrating a perfect Plane Of Play created by his disc, wrist, elbow, and shoulder.

Figure 1 shows 4-times World Champ Paul McBeth with a perfect smash, just prior to the disc ripping from his hand. We are looking at the Plane Of Play almost edge on, but my Photoshop mojo is not sufficient to show the slight declination of the plane towards the viewer. It is actually connected to the Line Of Play throughout the length of the pull and smash, as I have clumsily tried to show in Figure 2, (below) using Sketchup.

Figure 2. The Plane of Play aligned with the Line Of Play

Note the angle of the Plane Of Play IS the hyzer angle the disc will fly on. The Plane Of Play is also what the throwing arm travels on in the follow-through.

It is not so easy to create a true Plane Of Play because the joints in our arms are not pure hinges. Thus, it is up to us to align them correctly.

The Arm Joints

Let’s take a look at the complex joints which make up the arm, and how we can successfully create a Plane Of Play using them.

The shoulder is a strange socket-ish joint; not a robust ball and socket like our hips. It allows for a huge range of motion (and rotation!) and is supported by a highly complex set of muscles, tendons, and ligaments interacting with the clavicle, scapula, acromion and humerus bones. This complexity is why we often experience trouble with them in later life.

The shoulder is the (mobile) centre of the Plane of Play so it is not possible for it to be off the POP. So, at least this one is dead easy.

The elbow, while being a true hinge, also allows for pronation and supination of the wrist by way of the ulnar and radius bones crossing over within the arm (see bottom right of Figure 3 below). Please note the position of the hand relative to the upper arm changes as the hand supinates or pronates through ~180 degrees. If effectively rolls around the pinky finger.

To put the elbow on the intended POP, it’s necessary to lift it to a height which feels quite absurd to the new player, and this is why I teach people to get their elbow up “stupidly high”.

Figure 3. Hand and wrist mobility

The wrist operates as a hinge joint permitting flexion and extension (what ultimately flings the disc from your hand), but it also allows deviation of the hand in the lateral plane; Ulnar and Radial deviation, as shown in Figure 3 – right.

Putting the disc on the Line of Play and Plane of Play makes the hyzer and nose angle correct, and keeps it correct for the release.

In order for the hand and wrist to put the disc on the POP, the hand must be deflected to the normal limit of both supination *and* ulnar deviation. This is a strange feeling for most people, as no normal daily activity requires shaking someone’s hand while twisting it strongly clockwise so your palm is face up. It is even more alien to do this when your elbow is high.

A note about the forehand throw

The strength available to push the hand from radial to ulnar deviation is low, and the range of motion is correspondingly small when compared to the wrist’s hinge power and range of motion - and that is why in a forehand grip, we want the wrist hinge to be as close to perpendicular to the Plane of Play as possible for optimal power delivery and application. But that’s for another article

Some young and flexible people will have the luxury of being able to over-supinate, and over-ulnar-deviate to the point where the disc has gone beyond the LOP and POP, and this will result in discs crashing into the ground with nose-down attitude when trying to throw flat. But it’s a useful ability as an expert, in some situations.

On top of all this, the disc must be gripped such that the knuckle of the index finger remains above the Parting Line of the disc. The video below is the definitive Power Grip tutorial to date, made by Mike Cook – who has many other extremely valuable tutorial videos available on his channel.

If you have never gripped a disc as Mike describes, it is going to feel very weird indeed. But usually, the weirdness passes as the disc’s performance rapidly rises. However, every hand is different, and if you find that you need to grip the disc in a different way, that is OK, provided you keep the index knuckle above the disc’s Parting Line. (Figure 4 below)

Figure 4. Showing the mold Parting Line, and the PLH, measured in millimetres.

Fun Factoids

The Parting Line is literally where the mould comes apart, to release the disc from the injection process. The height of the PLH is a good measure of the stability of a disc, with high PLHs being more overstable, and low PLHs being more understable. This makes it easy to tell how radical a disc is, just by picking it up and looking at the profile.

You can tell how good a disc manufacturer is by how much flashing is seen or felt at the Parting Line(s). Flashing is small amounts of plastic injected into the minuscule gap where the mould parts meet – usually at the tip of the leading edge of a disc, and sometimes on the bottom rim. Low-quality makers often produce discs with obvious or extreme flashing. It’s caused by too much pressure in the mold, or too high a temperature, making the plastic too runny, and it gets pushed into the parting line gap.

In multipart moulds there can also be a ring of flashing on the bottom edge of a disc. Old worn moulds can also produce flashing, as they do deteriorate over time.

In extremely low-quality discs, the top and bottom of the mould might not even be aligned correctly, with one side overhanging and the other underhanging.

All flashing should be carefully sanded off using 120 or 150-grit paper before throwing a new driver disc, especially if you are planning on throwing it forehand; flashing on the bottom edge can rip the skin on your index knuckle in a good smash. You know how I know that’s true – right? :P

How to create a Plane of Play right now!

Grab a disc in your normal (new?) power grip, but with your wrist and arm totally relaxed. Now, put your arm straight out in front of you with your elbow straight. Now rotate your whole upper arm so that your elbow rotates up, and points slightly above the horizon. (You can close the elbow to easily see where it is pointing.)

OK, now deflect your wrist to its maximum ulnar deviation. This is the same as pushing your hand down for a handshake. I do this by pressing my thumb down very firmly on top of the disc, pushing my hand/wrist down with it. This controls the nose angle of the disc in flight. Push down less for nose-up flights, and push down more for nose-down flight.

Now supinate the wrist to its maximum ability. This is rotating your wrist so that the flight plate is face up. This puts the disc onto the POP, to ensure the disc flies with the right hyzer angle

DO NOT ALLOW THIS SUPINATION TO CHANGE

WHERE YOUR ELBOW IS POINTING!

Now flex the elbow to bring the disc into the right side of the chest.

The disc probably isn’t *quite* on the Plane Of Play yet, so make whatever small adjustments to supination and ulnar deviation are needed to bring that disc up flat and parallel with the plane created by your wrist, elbow, and shoulder.

There’s your very first Plane Of Play – DONE!

Not only that, but you just drew the disc into the Power Pocket; the most powerful position your upper body can be in.

Now – back to the actual issue: The Low Elbow

If a player pulls the disc through with their elbow low, then the only way they can possibly apply power to the disc is obliquely through the shoulder joint, because extending the elbow further will result in the disc smashing into the ground, just in front on the thrower. (Stand up and try it yourself.)

By far the most disc speed is added to the disc by the extremely rapid extension of the elbow joint when extended from 90-degrees (or less) to almost the full extension of the elbow. It is vital a thrower does not allow their arm to fully straighten during the smash, as this will hyperextend the elbow, injuring it instantly, or over time.

Figure 5: Mike Cook, smashing very hard indeed

For this reason, the thrower must stop their arm abruptly before the elbow straightens completely. (See Figure 5 - right. Mike C as seen from above. Note the arm does not straighten until after the disc has left the hand.)

Warning: Ultra Nerdy Stuff!

Conveniently, the natural stop point of the forearm relative to the upper arm (15 to 20 degrees before dead straight) is also the point at which, if you extend beyond it, the elbow has to reverse direction, and start travelling **towards** the LOP, instead of away from it (as it does up to that point) in order for the disc to stay on the LOP throughout the pull and smash.

Using a Mobius Line Puller, and slowly extending to the maximum reach of the arm demonstrates the biomechanics behind this.

Non-Nerds can now resume reading!

A low elbow will always result in a failed power shot. It makes it impossible to pull the disc along the LOP, because you introduce a truly rotary motion about the shoulder, instead of a truly straight motion using a high elbow. The only way a low elbow throw can be accurate is with the timing of the release, due to the unavoidable tangential nature of the release. (See the “Classic Rounding” article.)

The golden rule seems to be: if you feel like your elbow is stupidly high, it might almost be high enough!

As you begin to draw the disc forwards from the reach out, your elbow must be travelling along the LOP and staying on it until the disc reaches the right side of your chest. At that point, you must drive the elbow backwards behind the LOP, in order to keep the disc on the LOP. So, as the elbow is extending, the disc is moving along the POP and LOP.

Your shoulder to upper arm angle does not change (or rather, it does not decrease!) in the throwing motion up to the point where the disc reaches the Power Pocket, with elbow closed to less than 90 degrees, and with the elbow high, and on the POP. (Middle image below)

Figure 6. The elbow remains on the line of play until it opens rapidly from the chest onwards.

Only once the disc hits the Power Pocket, does the shoulder begin to open with tremendous force. This drives the elbow back behind the LOP and keeps the disc on the LOP by use of superb timing of the elbow extension and shoulder smash.

Point Of Fact

Some extremely powerful players will begin extending their shoulder earlier in the throwing motion, taking the disc off the LOP, but maintaining their POP. This can allow for even more power but requires more skill, as do all throwing motions which do not keep the disc on the LOP from the moment the disc begins moving forward.

More Mobius Line Puller stuff

Once again, here a Mobius Line Puller is extremely useful, because it can be set up to completely simulate your normal power shot, and you can perform the pull and smash in super slow motion. Hundreds of slow movements along the LOP, maintaining the proper POP provides the proper feeling at all stages of the throwing motion – and it is our ability to feel what we want to develop in disc golf.

On an MLP, any time you drop your elbow or fail to keep your hand on the far side of the disc, or if you close your shoulder below 90 degrees to your chest or position your torso or feet incorrectly, the disc binds up on the rail, yanks it one way or another, and starts trying to deviate from the nose and hyzer angle you set at the beginning of the pull.

The intensity of the feedback it gives for incorrect alignment of all body parts is quite astounding. Quite literally, the only way to get the disc to glide down the rail (LOP) with no resistance is to be perfectly positioned, perfectly in balance, and perfectly aligned, with everything on a perfect POP. Making this discovery for me was a revelation. Previously, I had no idea that the biomechanics of the backhand had so little margin for error.

And this is exactly why we can see a top professional card, with half a dozen world championships between them, on a double mando 20 metres out, and everyone misses the mando.

Even the tiniest deviations from the purest LOP and POP can result in discs heading in directions, or with nose or hyzer angles, that cause the most terrible outcomes. And the difference between a truly great shot, and going OB can be as little as half a degree on any one angle. sigh

It is also why switching from rounding, to a pull which is straighter (But still not completely straight) yields good results almost instantly, for most players.

The relationship between LOP, POP, Nose Angle and Hyzer Angle

If the elbow is dropped during the pull, then something has to give biomechanically, and what gives is either the Line OR the nose angle and hyzer angle. They change as the disc moves away from the intended line.

Put another way; a disc which is pulled along a path which is not the LOP will necessarily involve changes to the nose and hyzer angle as the disc comes through. You will see this happen mid-pull on the some of the world’s most powerful throwers, because they have abandoned the straight pull, in favour of a Wide Rail, or an early shoulder smash, which is potentially more powerful, but much harder to perform.

But wait, I see good players all the time whose discs aren’t on the Plane Of Play!

Indeed you do, but never on any long-distance, full power throws, which exceed 110 metres. Another possibility is when you see Truly Big Arms going for big distance; as above.

When you are an expert, and distance is not an issue, it’s not necessary to maintain a POP in your throw, and you can concentrate on other aspects of a throw: ranging, hyzer and nose angle to obtain maximum accuracy. In those times, you do not need to have everything on exactly the same plane.

And there are times when you do not want the disc perfectly aligned with the Line Of Play and/or Plane Of Play. Sky Anhyzers for example, are thrown upwards, but with the nose down effectively, to prevent the disc from stalling out as it climbs, and fading hard left, instead of climbing over the top, turning right, and then enjoying a long sled ride down into Anhyzer Valley, before fading left at the end.

You may also throw a disc intentionally nose high, to slow it down rapidly, and cause it to drop quickly, after flying under a low ceiling. Or to cause it to be slapped down by a tailwind, using it as part of your distance control.

What happens if my elbow is just a little bit low?

Good question! This is the most insidious error, and it happens very easily. If you allow your elbow to fall below the LOP during the smash then it’s likely the disc will leave your hand on an anhyzer angle – or at least, with less hyzer than you intended.

If you combine a rounded pull with a low elbow then you get many anhyzers and many unintended rollers.

Any time a part of our lever set falls off the POP then you’ve got problems with accuracy.

Chris, why do you keep blathering on about the LOP and this POP thing?

Because the vast majority of us do not have enough talent to throw well without good form. Technique and timing are *everything* to us because it’s the one and only thing that can lift our performance over and above our level of talent.

I want to point out that many pros have bad form in one aspect of their game or another. Schusterick has one of the nastiest looking putts in the game. Sexton has a shocking hop in his FH drive. Catrina Allen reaches back too low. Valarie Jenkins dips like crazy.

Of all current players, probably the best form in every aspect of the game is Paul McBeth, who shows impeccable form and outstanding timing more often than any other player and using every type of throw.

The point is this: unless you are extraordinarily talented, you can’t fake it with talent!

OK, so if it’s all technique and timing – what about the timing?

Well, I’ve given you some timing clues in this article, but to be fair to my own rather limited talent and knowledge, I don’t have much more in the way of advice to provide, but I will start working on an article on the subject, because there *are* some pretty well-established timing cues, which if broken will reduce a throw’s potential.

In particular, the timing of the beginning of the pull. I wish I had a dollar for every drive I have seen, where the thrower begins to pull the disc forwards before their heel has contacted the ground.

I also wish I had a dollar for every person who reads this article and gets something out of it. Ah well, dreams are free.

Take it easy everyone, and… POP it like it’s hot!

And then… park it like it’s hot.

– Chris 'Dingo' Davies

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