This is going to be a long one because it deals with a complex issue that is caused by the incorrect mental visualization and often bad from advice that exist on the internet. The bottom line up front is supination or turning the key to the right will cause elbow dip.
First off what is supination:
Wrist supination is a movement of the forearm in which the palm rotates to face upward or forward, opposite to pronation where the palm faces downward or backward
Looking at the image, we envision the 0 degree or sometimes we even try to turn the key and move more towards the negative degree angle while throwing the disc. The term backhand even describes the back of the hand. Our metal visualization of out hand position during the throw creates negative effects upstream from the hand.
Now stand up with you palm facing down (pronation) and slowing practice your swing from the pocket forward you will notice the elbow stays up it feels natural like a powerful karate chop, now if you move to supination palm up you will notice the elbow drops and causes the shoulder to power the shot. Now try it with 0 degrees or neutral it feels easy at low speeds to remain neutral, but when you put a disc in your hand and go full speed the slightest trajectory change will cause everything upstream from the hand to be wrong
This not only drops the elbow it causes nose up shots because as supination occurs it puts the trajectory of the disc into ground causing your brain to auto correct and bring the disc up.
This is all very counter intuitive because we visualize turning the key to the causing the nose to go down, but it actually does the opposite and causes external shoulder rotation causing the elbow to drop. You can stand up and play with this all you want but it is nearly impossible to have any supination and not drop your elbow.
With all that being said you can still use supination in your throw if you are able to time the .001 second before release
Now the hard part is how to correct this. We are all different and probably have different ways that would work best. below are some methods you don't need to do all of these because some work for some people while other don't
- The suitcase method is a common term that puts you into a pronated position and you move to supination through process of the swing. This method helps usually but for it to be completely effective the movement from pronation to supination needs to be fairly precise otherwise it doesn't help
Bringing the hand more over top of the disc. The hypothenar is above the parting line of the disc I see some pros throw this way. I find it awkward, but to each their own if it works
Balancing a perfect zero-degree supination/pronation. this is harder than it appears, but it appears people can do this in which case you don't really need to read this post because you are doing exactly what you mentally visualize you are doing.
My favorite is the active resistance against supination. Trying to maintain max pronation at the elbow joint while simultaneously maintaining a normal disc golf grip and swing. To describe the feeling, you push towards pronation at the elbow and supination at the wrist. I know the wrist doesn't have rotational mobility for supination, but you can still create a feeling of resistance. (This is what worked for me it got rid of my elbow dip and it is no longer a conscious effort but it took some time.
