Old age and back problems probably go hand in hand. My chiropractor tells me if I would quit lifting 50lb. boxes of clay, and sitting hunched over a potters wheel when throwing clay would help. Not going to quit, so no pain-no gain or something like that. I do wear a lifting back support when I lift clay or throw clay, or cast boolits. Years ago I could cast a thousand boolits with a 2 banger in one session--no more however. Seems like that changed when I past the 60 mark. Seemed like about an hour of casting at a time was about all the back would take at that time.
Then, a few years back I started going to my grand daughters swim meets and sitting on bleachers with no back support. Noticed a few people had those fold up seats on the bleachers, the kind that are padded cloth w/adjustable straps on the sides, and they sort of conform to the back when you sit on the bottom. So I bought one, and with adjustment I had back support.
I cast sitting down, on a straight back chair, and since the seat helped me when sitting on bleachers, tried it in the chair when casting. Made a world of difference. I found one of the things that even has a kind of small padding high on the back in a goodwill store that helps to keep you sitting straight.
Using one of these things has helped me, and I have been using one now for about 5 years. Have two of them and use one when I am reloading as well. Both casting and reloading when seated requires reaching, l and these seats might help some others on this forum who have similar back problems.
1Shirt!