SLP AND SHOULDER , ELBOW, WRIST PATHS

[VGB]

Vince, I've been wondering what creature your avatar was, then saw a chance article on the BLOBFISH having been recently voted the world's ugliest animal.

Its bad press and slander. He loves his mother and is very kind to other animals, even beavers

regards

Vince

[Marc Fauvet]

[Dirk le Roux]

Its bad press and slander. He loves his mother and is very kind to other animals, even beavers

Slander indeed. Sorry Vince I did not mean to badmouth Blobfish. He's kind of cute. Just conveying what the papers said.

All the best,
Dirk

[Paul Arden]

I actually thought that was Vince

[Walter]

No, no, no! This is Vince.

[VGB]

[gordonjudd]

I think the up part of the wrist on final rotation is actually a consequence of the rod unloading.

Paul,
If you could see the motions in slow motion I think you would find the up-path of the hand is a result of straightening the elbow.

The bottom of the dip generally happens when the rod is at or near MRF. That is when maximum acceleration force is being applied to the line. Thus by straightening the elbow at that point you tend to maximize the distance the tip travels while near maximum force is being applied to the line. Straightening the elbow increases the angular velocity of the butt as well as increasing the distance the hand moves from MRF to RSP. That is much more effective in producing higher line speeds than if you were to just rotate the wrist at MRF.

Because of style differences, I don't think we understand the kinetic linkage flow of the rotation we use in casting (we couldn't even agree if it was proximal to distal or the other way around in the kinetic chain thread) but I would agree with John that we should:

Look to the body to generate speed, not the rod.

But mostly in this case I think it's rod-driven as opposed to rod-driving.

From an energy standpoint point I don't think that is the case. The energy added to the line from MRF to RSP in the conventional cast Grunde analyzed for Mathias' 10 meter cast was about three times larger than the energy that was stored in the rod at MRF. I would expect that energy ratio would be even larger for a distance cast; so just as John observed, I think the driving force for a distance cast is coming from the caster, not the rod.

Dirk, thank you for taking the time to plot the paths of these rotation sources for different casters. It is interesting that different casters produce different paths in their casts, but still get world class distances with their own distinctive styles.

Gordy

[Walter]

we couldn't even agree if it was proximal to distal or the other way around in the kinetic chain thread)

Heck, we can't even agree if conservation of momentum is real or imaginary. Perhaps one of the issues with linkage flow is that we are trying to develop universal theories to cover a broad range of application and equipment. It's much easier in sports where javelins, baseballs, discii, etc. are all subject to a narrow set of specifications and athletes are trying to achieve a single goal but even then there are many debates about how to best achieve that goal.

[Paul Arden]

Hi Gordy,

Thanks, but why would the straightening of the elbow result in an up-path of the hand?

Cheers, Paul

[gordonjudd]

but why would the straightening of the elbow result in an up-path of the hand?

Paul,
I think there is also a shoulder rotation involved as the elbow is straightening to get the rod extended away from the body and positioned at an upward angle at around RSP1. That produces a more optimum upward launch angle when the loop is initially fully formed (at MCF) and probably also produces a better rod angle for shooting line.

I do not have any videos of casters using a 170 distance style where the rod finishing position might be more horizontal and be a counter example to the typical release position you see with good distance casters in the U.S. so this observation of seeing an upward rod angle at the release point is probably not true for all casting styles.

However I think most good distance casters end up so there is nearly straight line going from the line hand in back of the caster to the extended rod hand in front. I don't think the length of the haul could be made any longer with a different release position.

This finishing position of one of Tim Rajeff's distance casts using a WF line is a typical example. The frame by frame hand path in that cast is tracked by the green dots in the photo and shows a rather broad up-to-down path from RSP0 to MRF and then a sharper down-to-up path from MRF to RSP1.

You see similar "Echo man" release positions for the casts Dirk showed in post #12

Gordy