I've had sporadic tingling in the top left of my back for around three weeks what could this be?

Muscular pain issue: You have trigger points in the muscles associated with the shoulder that trigger on and automatically turn off. A massage person can find them and deactivate them with ease. Some of the triggers can scream so loudly you will think you are dying or having a heart attack. I have a few patient who actually had spinal surgery to fix their spine?! it was not the issue. Ck serratus mus. Too.