Upper body workout

I injured my lower spine a few years ago (lifting weights thankyouverymuch…at least that is when I noticed it). It’s a long story, but I’ve yet to get it treated. I’ve gotten to the point where I might as well be wheelchair bound since walking and standing lasts no more than 5 minutes and sitting in a chair begins to be uncomfortable and painful at around 20 minutes. It also affects my sleep, blah, blah, blah. I hate it.

Anyway, I miss lifting weights, I miss my strength. I keep thinking if I sit in a chair and do upper body stuff with dumbbells, then I can at least be doing something positive for my health.

If I can accomplish this, I want to get the most out of it. Should I stick with the typical 3 set/10-12 rep and then upping the weight? Or is there another route I can do to ‘maxercise’ it?

I can answer any questions you have, just did not want to bore anyone with my stupid back issues.

Thanks!