I Have A Small Area In My Back That Is

I have a small area in my back that is numb, no feeling at all. It is about 6" centered below my shoulder blade on the left side about 5" from my spine. 9 months ago I sustained an injury to my left shoulder that caused pain in my neck which I still suffer from. I wnt to two chiropractors, one used acupuncture, no relief. Could this numbness be related to the injury? Who should I see for examination?