Sorry to hear that. Back pain sucks and you don’t realize how much your back is needed until it doesn’t work like it should.
Have you tried physio instead of a chiropractor/massage therapist? I’m very skeptical of chiropractors. Massage therapists are good but won’t get to the root of a problem if there is one.
I’m gonna be optimistic and say that the hamberders or dementia is going to catch up with him before 4 years is up.