Movement · Shoulders

Scapular stability

The shoulder blade holding its place on the ribcage while the arm works. The arm has no bony anchor to the body — it hangs off a blade that floats on muscle — so before the arm can do anything, something has to make that blade a steady platform. The serratus anterior holds it flat against the ribs and the middle and lower trapezius and the rhomboids keep it set. Good looks like: the blade staying flat and quiet against the ribcage while the arm moves, no winging away from the ribs, and no shrug up toward the ear to borrow stability from the neck. When the blade will not hold, the neck holds it instead — which is why an unsupported shoulder blade shows up as a sore neck.