Angular Velocity

I posted this Gif in another thread but I wanted to show you what Angular Velocity is why you don't want your DD to long arm the ball.

Danielle Lawrie






Now look at this video and it will explain it all.

[video=youtube_share;tab1VlV4R0Y]http://youtu.be/tab1VlV4R0Y[/video]

Here is a closer look into the back swing.

Great post. The classic example is what you see with an ice skater when they bring their arms in during a spin.

I actually think this particular phenomena is not the big reason to ensure a nicely bent arm. The effect of the bent arm allows that lagging segment to then suck energy from the preceding segment and whip around. conservation of angular momentum still applies but it is not just that a shorter arm allows a faster rotation, it is that a shorter BENT arm allows a faster rotation AND allows a whip to occur, add in a stoppage of the upper segment and a whole lotta energy gets into the ball at just the right time.

JJsqueeze said:

The effect of the bent arm allows that lagging segment to then suck energy from the preceding segment and whip around.

Click to expand...

Yes, I agree.

If upper arm reaches vertical *before* the lower arm/ball, AND stabilizes,
then IR of the humerus, plus Pronation of the forearm, become "adders", producing acceleration of the most distal portion of the chain (hand/ball).

IR of the humerus initiates the "whip" of the ball past the elbow joint,
and the subsequent pronation of the forearm (from a "palm-up" supinated position) "mid-whip" accelerates the ball even more.

The idea is that two portions of the kinetic chain are purposefully kept "loaded",
until the release phase of the pitch. The timing of the "unloading" sequence determines acceleration and subsequent pitch velocity.

I agree completely but the earlier the changing the moment of inertia does increase velocity compared to going long arm till 9 oclock.

JJsqueeze said:

I actually think this particular phenomena is not the big reason to ensure a nicely bent arm. The effect of the bent arm allows that lagging segment to then suck energy from the preceding segment and whip around. conservation of angular momentum still applies but it is not just that a shorter arm allows a faster rotation, it is that a shorter BENT arm allows a faster rotation AND allows a whip to occur, add in a stoppage of the upper segment and a whole lotta energy gets into the ball at just the right time.

Click to expand...

I love that pixel delta per frame gif.

So how do you go about teaching a loose arm but still keeping it bent. What type of cue would one use for this.

Here are my cues...the first ones are used at the beginning of practice the last ones at the end...
"Loose and whippy"
"Throw your elbow not your hand"
"Feel the snap"
"For God's sake it's been 2 years and we are still working on this?"
"You must have a degenerative joint disorder that leads to chronic stiffness in your elbow"
"How do you feed yourself with a fused elbow"
"Wiping your butt just be a real challenge kid"
"Yeah well I don't want to practice anymore either"

JJsqueeze said:

Here are my cues...the first ones are used at the beginning of practice the last ones at the end...
"Loose and whippy"
"Throw your elbow not your hand"
"Feel the snap"
"For God's sake it's been 2 years and we are still working on this?"
"You must have a degenerative joint disorder that leads to chronic stiffness in your elbow"
"How do you feed yourself with a fused elbow"
"Wiping your butt just be a real challenge kid"
"Yeah well I don't want to practice anymore either"

Click to expand...

LOL you must be at my DD's practice too.