DD's opening front shoulder.

[MikeP]

Sorry for the hijack, my dd had/has the same problem as the op's dd and I was very interested in the responses.

 

[_MIA_]

I was probably unclear in my initial question. I meant that the shoulders start the upper moving once the lower half start. Sorry.

Well what I am saying is that you don't want to try and actively turn the shoulders. Coil, move out balanced (argghhh!!) while trying hold/increase the coil and creating stretch in the core and upper back, launch the swing using your hands/forearms. You do this and the shoulders will rotate without actively trying to rotate them..imo course.

 

[Bobby Shirer]

Yes . Better than your still shots for sure ! LOL.

Yes centrifugal., that’s the decel component of the swing. Acceleration is a change of speed over time.

However you gotta word it so you learn, I don’t care. But it ain’t rearward and it ain’t by dragging it through with your shoulders. Where would the change of speed over time be in your model? Oh yeah there isn’t one. It’s called drag.

Who said anyone was REMOVING FORCE? I was just changing the speed of an object over time... ACCELERATION !

Here’s how I teach my beginners... Try cracking a dish towel without deceling the ‘handle’ side.. That’s your model by the way, rotate/supinate into the ball with your body/shoulders. Now try and decel the side you control after you start to accelerate it.. Acceleration into the ball ! Whip ! It’s exactly what Ted and Mookie were doing. Here’s Pete telling you also.




Ps. Since were gettin all scientific. Conservation of force(energy) says you cannot change force. It cannot be created or destroyed. It can only be transformed or transferred from one form to another.

Cracking a whip is still the application of centripetal force and the rotational component within. Can't crack a whip with strictly linear acceleration/ deceleration. The fat end makes an arc and the rest of the whip follows. But the whip only extends to one spot and if you apply that to hitting a ball, you'd better be perfect when picking that spot.
Why not use focus on rotation to constantly accelerate the barrel?
An object moving in a circle is experiencing an acceleration. Even if moving around the perimeter of the circle with a constant speed, there is still a change in velocity and subsequently an acceleration. This acceleration is directed towards the center of the circle. And in accord with Newtons second law of motion, an object which experiences an acceleration must also be experiencing a net force. The direction of the net force is in the same direction as the acceleration. So for an object moving in a circle, there must be an inward force acting upon it in order to cause its inward acceleration. Force is applied over a longer period of time and the barrel stays extended and in the zone longer. Less perfection is required.
As for creation of force, what are muscles for if not the transformation of energy from one form to another?

 

[Bobby Shirer]

Well what I am saying is that you don't want to try and actively turn the shoulders. Coil, move out balanced (argghhh!!) while trying hold/increase the coil and creating stretch in the core and upper back, launch the swing using your hands/forearms. You do this and the shoulders will rotate without actively trying to rotate them..imo course.

I'm confused. All this talk of coil and stretch and balance.... How do you launch the swing with the hands and forearms?
What is the action on the bat?
Why coil, stretch, and balance the core if not to use it to turn the shoulders?

 

[_MIA_]

I'm confused.

I hate it when people are condescending.

I'm confused. All this talk of coil and stretch and balance.... How do you launch the swing with the hands and forearms?
What is the action on the bat?
Why coil, stretch, and balance the core if not to use it to turn the shoulders?

Again, who said the shoulders don't get turned/rotated..obviously they do and yes what you mentioned is used to turn the shoulders.

The forces/moments on the bat handle are a combination of hands/forearm directly acting through those small muscles along with forces/moments created by a rotating/translating body and yes this includes rotation of the shoulders..but again the point is you are not actively trying to rotate the shoulders.

 

[Bobby Shirer]

I hate it when people are condescending.

Again, who said the shoulders don't get turned/rotated..obviously they do and yes what you mentioned is used to turn the shoulders.

The forces/moments on the bat handle are a combination of hands/forearm directly acting through those small muscles along with forces/moments created by a rotating/translating body and yes this includes rotation of the shoulders..but again the point is you are not actively trying to rotate the shoulders.

Big and small muscles directly acting.... blah blah blah..... What do they do to the bat? How does the bat move in space relative to the body and relative to the earth as a result of the actions of the hands and forearms?

 

[_MIA_]

Big and small muscles directly acting.... blah blah blah..... What do they do to the bat? How does the bat move in space relative to the body and relative to the earth as a result of the actions of the hands and forearms?

I thought we were talking about rotating shoulders? Why move the goal post? To answer your question:

 

[Work=wins]

Cracking a whip is still the application of centripetal force and the rotational component within. Can't crack a whip with strictly linear acceleration/ deceleration. The fat end makes an arc and the rest of the whip follows. But the whip only extends to one spot and if you apply that to hitting a ball, you'd better be perfect when picking that spot.
Why not use focus on rotation to constantly accelerate the barrel?
An object moving in a circle is experiencing an acceleration. Even if moving around the perimeter of the circle with a constant speed, there is still a change in velocity and subsequently an acceleration. This acceleration is directed towards the center of the circle. And in accord with Newtons second law of motion, an object which experiences an acceleration must also be experiencing a net force. The direction of the net force is in the same direction as the acceleration. So for an object moving in a circle, there must be an inward force acting upon it in order to cause its inward acceleration. Force is applied over a longer period of time and the barrel stays extended and in the zone longer. Less perfection is required.
As for creation of force, what are muscles for if not the transformation of energy from one form to another?

The rotational aspect is in the core. I said this already. The swing is a transfer of momentum into an object.

As far as being perfect, that’s what hitting is. When cracking a dish towel I am actually very accurate because the end of towel will go where I released or deceled the towels lead end. If your thinking is get the barrel on plane early and leave it there as long as possible. That is not what good players do. Getting the barrel on plane early is early commitment and is detrimental.

The hands should get on plane, with the barrel above the hands until it’s time to release or commit to the ball.



Notice how the core rotates back while the hips move forward in space. That’s the power source. Momentum and torque while leveraging the ground.

Like Aimee actively stretching the obliques against the hips, grandal is using momentum to stretch the obliques reactively against the hips.. If done sequentially it will be done reactively.

If you can feel this move and insert it into your swing. You will understand why the shoulders GET rotated and we are not trying to rotate them.

In all honesty. Try doing this. You will feel a ton of torque and no need to actively rotate the shoulders.

 

[Bobby Shirer]

I thought we were talking about rotating shoulders? Why move the goal post? To answer your question:

Not to be condescending but you said, "launch the swing using your hands/forearms." and I want to know how? Why do all the coiling and torquing if the hands launch the swing? Are the hands coiled, stretched, and loaded?

I didn't move the goal post. I just don't believe the hands or forearms swing the bat. There are muscles in the shoulders and upper arms that cause the bat to rotate.
The hands hold the bat.

The "shoulders" (or should we call it the musculoskeletal apparatus of the upper torso where the humeri adjoin) rotate around the spine only a few degrees. Each vertibrae of the thoracic and lumbar spine displace transversely a few degrees to circumvolve the musculoskeletal apparatus of the upper torso where the humeri adjoin.
The shoulders .... "get rotated". Duh!
But it's easier to tell your daughter to turn her shoulders.

As far as the gif above. He's using his lats to pull the barrel down and his rhomboidei to pull the knob forward and these actions cause the barrel to turn in a rearward arc. The hands hold the bat.

PS...Since we're trying to complicate things so that we can feel all smart and such......you don't retract your scapulas. They get retracted by the rhomboid major and minor muscles. Now try asking your daughter to contract her rhomboids....HAH!

 

[Shawn]

Cracking a whip is still the application of centripetal force and the rotational component within. Can't crack a whip with strictly linear acceleration/ deceleration. The fat end makes an arc and the rest of the whip follows. But the whip only extends to one spot and if you apply that to hitting a ball, you'd better be perfect when picking that spot.
Why not use focus on rotation to constantly accelerate the barrel?
An object moving in a circle is experiencing an acceleration. Even if moving around the perimeter of the circle with a constant speed, there is still a change in velocity and subsequently an acceleration. This acceleration is directed towards the center of the circle. And in accord with Newtons second law of motion, an object which experiences an acceleration must also be experiencing a net force. The direction of the net force is in the same direction as the acceleration. So for an object moving in a circle, there must be an inward force acting upon it in order to cause its inward acceleration. Force is applied over a longer period of time and the barrel stays extended and in the zone longer. Less perfection is required.
As for creation of force, what are muscles for if not the transformation of energy from one form to another?

Do you know Jack Mankin's material?