I have spinal problems as well as MS, my spinal canal is too narrow so it presses on the spinal nerve ("stenosis"), and facet joint arthritis with it. This causes me chronic acute lower back pain and also referred pain in my hip and leg, making standing and walking very painful. I also have some milder osteoarthritis in my spine but I'm not too aware of any pain from it, or maybe the stenosis overpowers it. I also have osteoporosis in my lumbar area and head of femur, but no pain from it.
There isn't a pain killer on this earth that helps except for resting by sitting or lying down. I now have a combination of nerve block and steroid injections into the spine, in different areas, which sometimes helps and sometimes doesn't. Short of that, surgery is the only other option but we're trying to avoid it (for now at least!).
I also had problems with my knee joints many years ago and had cortisone shots for those too and they helped. I rarely get pain in my knees nowadays, but I did have to give up certain sports in order not to trigger it again.
Years ago, it was suggested I try a
TENS machine for my back. Someone else I knew who also had spinal stenosis found it helped. Unfortunately, I didn't. Might a good TENS machine help?
I agree that hydrotherapy is an excellent way of exercising as the water supports you and makes exercising much easier and in a gentler way.
