Here is a scap that starts "pinched" in the setup. What do you think about the term scap circling?
Hey Shawn, Spartans and Bass have already described pretty well. My thoughts are the same. The scap pulls back into the spine using the back muscles (not shoulder or arm created). This takes the arms out the equation. Some hitters start pre pinched and some do it as they move out. Either way - this action is loading the rear leg. The rear hip pulls around the rear leg, the lower back and scap. This all happens to continually load the rear leg. The rear leg gets loaded by wanting to resist this rearward pressure. Jryan had a really nice video showing how continually pulling back around the rear leg actually gets you forward because the rear leg will react that way if the pull backs are correct and never release.
The key piece to all of this not letting the scap/lower back/rear hip release it's "force" of pulling around the rear leg. The scap pressure drives down the length of the spine as the rear leg starts turn everything forward. What is hard to see and equally hard to get the feeling for is that the torso tilts via the rear hip joint as the scap pressure drives down the spine. This essentially creates the shoulder tilt and allows the shoulders to be bypassed.
So, I wouldn't describe it as scap loading either. If the scap unloads you push and use the arms and lose the ability to really use the bigger muscles without max effort of trying to use the bigger muscles. The swing is over in a snap. Players that start to feel this are amazed at the quickness and you can hear the difference off the bat as they really compress the ball.
Here is one of my hitters figuring out how to use her back to pull the scap into the spine. IMO - if you get the scap right the ability to use the lower back correctly is significantly increased. Watch how her lower back reacts when she engages the scap. Not only are the letters moving but watch the "22" at the bottom of the numbers.
I'm just add onto this great post with something that might help...or not.
That resistance is the rear leg trying to turn internally (internal rotation) while the hips are turning the opposite direction. The foot feels ER(external rotation/clock wise rotation) against the ground. Feels like 'wringing a rag'.
Here is a scap that starts "pinched" in the setup. What do you think about the term scap circling?
