A pinched nerve may be involved. Gastroesophageal reflux disease (GERD) may cause referred pain between the shoulder blades, affecting the back. Inflammation in the pancreas may also cause this pain.

"Pinched nerves can happen anywhere in the body but ... a muscle that connects the neck to the shoulder blade, to relieve ...

Pain from a pinched nerve in the neck can make people ... then back down and back, pushing the shoulder blades together. Repeat this move for 30 seconds, then reverse the direction.