Woodsmoke, I don't have a frame in my back - so I have really no idea if any of the following would help you.
I have 4 lumbar verterbrae with depressed disks which caused me considerable pain in the past. But things are better now. Here are my rules for me - not for anyone else.
Only use painkillers if the pain is acute or you are immobilised. I realised that the back pain when it was not acute, was teaching me things - pain meant wrong, no/less pain meant right. At the beginning I was just taking painkillers to make me feel comfortable - but, of course, I didn't know when I was doing something bad.
Keep moving. Doctors on a programme I saw said that there is no "right" chair - the problem is people sitting still for long periods, one should get up and move periodically. Equally, walking is good.
The idea behind this is that the spine will find the right place when there is gentle movement, but being still means all the pressure is on the same place and until you start moving the spine can't readjust.
You have a frame, and I don't know what that means, but I am wondering whether that should be re-adjusted from time to time? Sorry if that remark is dumb - I am ignorant about this sort of thing.
What really helped me was related to movement - I have a high bar, from which I can hang and stretch myself. Surprisingly I found that press ups helped my back pain (immediately) - naturally this means good form press-ups (straight back etc.).
When I got the first bad attack, I was in hospital - I couldn't sit or stand or lie, but a doctor gave me quick acupuncture and the "knife in spine" just became an ache. Then I had physiotherapy and my first meeting with a hammock. A hammock was a real relief when I had an attack at home - a string hammock so that you don't slip and slide. You can then manoevre yourself with your legs up high and the weight on your upper back, relieving the lumbar - and you should gently wiggle your a hips a bit - to give the spine the movement it needs as mentioned above.
I now use a hammock a lot - I'm sitting in one now.
I also do weight training to strengthen my back - but always keeping to strictly good technique - if I don't, my back gives me a gentle "wrong" warning
I realise that having a frame in the back is not the same as slipped disks - but maybe there was something in what I do that you find useful.
One other thing - pain is soul destroying and tiring - I find meditation good - it calms the innerself and gives one an inner resilience. It won't take the pain away but will allow a certain detachment from it.