Recently diagnosed with Achalasia,

Oh yes, mine gets terrible right between my shoulder blades. It is worse in my back, than in my chest. I had botox with minimal success, it drops the pain down - but I still have pain

I think it is possible for pain to be transferred to other places in the body from where the origin of the problem is because of the way the nerve system sometimes works.  People with achalasia do suffer from painful spasms in the chest.

Yes I do, especially for a few hours after meals! I get spasms in my chest and a steady pain located at my diaphragm/ sternal area that goes right through to my back.  The pain in my back doesn't spread throughout my back, it's centered in my spine, about where my bra strap does up, directly oposite the area where it's hurting in the front. 

Prior to getting diagnosed with Achalasia (only by manometry so far, seeing specialist at end of month) I thought the pain in my back might be arthritis.

When I first had issues I thought I was having a heart attack and after that was ruled out twice I would have anxiety attacks thinking I couldn't breath which put me in full panic mode.  After going to the ER ($100 a visit plus tests, other) multiple times they gave me something called a GI cocktail (numbs and relaxes esophagus).  My doctor felt bad for my pocketbook, told me how to mix it, and also gave me Dicyclomine Hcl 20mg tab for spasms.  The Dicyclomine was a life (and wallet) saver.  Any time I start to feel like my chest will spasm I take 1/2 a tab, which usually works.  If it doesn't work I take the other 1/2.  I also try to avoid stress, which causes most of my chest spasms, stay hydrated and drink something warm.  Good luck.