I Have Had This Burning Muscle Pain Throughout My Left

I have had this burning muscle pain throughout my left shoulder blade area for the past few years. It feels like someone is holding a match against my muscle and it is burning. It never really goes away, but stretching it and heat and no movement helps temporarily but there is nothing that takes the pain away. Can you help me with some possible diagnoses? I am a healthy 24 year old female. No health problems.