Control of the scapula is immensely important for development of upper body strength, posture, and general control of oneself. I have seen far too many people who are either locked up in this area or lack the coordination to be able to control, move, and stabilize from their shoulders.
The shoulder joint is incredibly complicated, and today will not be an anatomy lesson. I simply want to make you aware of several positions to be able to use them in your training and daily life.
The scapula(shoulder blades) are floating bones located around the sides of your upper back. Their specific placement will have a massive effect on total body output. This is especially important when working on handstands and other acrobatic movements.
To simplify things, let's say the scapula move in two directions. They move forwards and backwards, also known as protraction and retraction. Also they move up and down, known as elevation and depression.
In a relaxed standing position we want(more or less) the shoulders depressed and neutral in terms of protraction and retraction.
From here, you can elevate the scaps by strongly pressing your shoulders up:
You can go into protraction by rolling your shoulders forward and around your back to create a round shape:
You can go into retraction by strongly pressing the shoulder blades together behind you:
You can also combine elevation with protraction:
As well as elevation and retraction:
These exercises are to develop control of the scapula as well as to diagnose what your restrictions are.
After you have mastered these position the true value can be demonstrated.
Attempt to go through these positions of the scapula in loaded position, examples being a pushup position, handstand, hanging, etc. Make notes of how they feel differently, and what feels more stable.
When you have understanding and appreciation of shoulder placement, it will do quite a bit for your movement efficiency. Every upper body strength movement has a very specific scapular position that will make the movement work best. The answer is not always the obvious one.
This is why I think it is very important in someone's personal development to be able to explore enough to do things differently. The placement of the shoulders is only one small part of the whole.
The idea is to be able to experiment enough to be able to find out for yourself why we do things the way we do.