Try This Right Now!
Round your shoulders as far forward as possible (think sitting in front of a computer with really bad posture) now maintain this position and try to raise one or both arms overhead. Take note at how awkward and difficult that felt as well as how far up your shoulders went.
Now sit up nice and tall with good posture (even pinching your shoulder blades together slightly) and go ahead and repeated the above process.
Which one was easier?
When your shoulders are in a forward position such as in the first example, you are lacking shoulder extension. If we can’t even get our shoulders into a neutral position all other motions are going to be impossible to safely and correctly achieve!
How does this happen?
I see this as a twofold problem. The first and bigger problem is the fact that everyone is stuck sitting in front of a desk in this poor position for eight plus hours a day. You couple that with almost no one in the fitness industry trains shoulder extension, most programs have push and pull movements. But these are almost always overhead or in the front of the body (both of these are shoulder flexion positions)
Why does this matter?
When we lack shoulder extension (or any motion for that matter) we can’t properly load our own architecture. This is going to lead to unevenly distributing loads else where(think driving a car with a flat tire). In the case of the shoulder this results in shoulder, elbow and wrist tendonitis.
To help resolve these issues, this is why one of the top priorities addressed with all of our onsite and remote clients is shoulder extension.