Sandy,
How much massage do you get? For me it is not the funnest thing in the world but a NMCT would help out greatly. If your scapula or rhomboids... a large muscle that extends between your shoulders and up to your neck is affected mostly by your pectorial muscles (specifically minor pectorials which are under the major ones) This will help out your middle back, neck cervical area.
For your stomach or rib cage. Yes there is a correlation, especially if your scapula is sore. Once a muscle over compensates in any one are the rest will be affected.
For the ribcage, my massage therapist decided to have me lay on my side, pillow between the legs for hip support. She rubbed in between the ribs and serratus (for most it is the ticklish part on the side), rubbed on my lat (lattisimus dorsi, the big muscles on the side of your body) and terres muscles (those are the ones at the back of the armpit) often sore but no one notices until it is very painful.
The stomach muscles will be affected if your lat, serratus, low back or leg muscles have "issues". So I say this, ask a therapist to rub on your soas (sooo aasss) muscle. This muscle attaches everywhere to the moving parts of your middle body. Think of a cat, you know how they can hunch there back or be so nimble? That is not the same function in people but the idea is the same. The soas attaches to your rib cage, lumbar and hips. There may be more but that is all I know for now.
This does not feel GREAT but if you could have your therapist "roll" your abs it will lower the stress in your low back, provide better stability and allow your muscles to relax all the way up your body. And it won't be difficutl to stand up straight.
Hope this helps. If I could send you a URL to ask me any question you want about back, limb, muscle group pain or back pain could I? If not that is fine we will stick to the forum.... thanks for reading,
MrBurton