I had tendonitus in both left and right arms, I can understand your health issues, went to a Specialist (Doctor) he met me at the hospital and gave me an injection in both arms, my pain was almost unbearable at this point - it was amazing how soon the pain was relieved. My husband hired a carpenter to redo my sewing area, and I found that since this was done, I no longer have back issues and my arms do not bother me at all. I always wear my quilting gloves, and I believe that helps with the shoulder and arm stresses.
The pictures that I am attaching show the machine was dropped into the cabinet, a plexiglass piece was cut to fit around my machines (I have 4 machines and I have a plexiglass insert for each of the four), and he made an extension that lays on the top drawer, with a support under the drawer - the extension holds the bulk on the quilt that I'm working on - and I don't have to tug it up and onto the sewing table top. The sewing machine sits on a shelf inside the sewing cabinet and a hydraulic lift was installed inside the cabinet that the shelft sits on, and I can raise and lower this shelf depending on which machine I use. I also have an OTT Lamp and a magnifier glass, so I don't have to bend over the machine to see what I am working on.
I hope this can assist someone on QB, Thanks for looking.