It's easier to get SSDI(plus your age is a big plus) with lower back problems rather than upper back(I have cervical spine arthritis ). If you can't stand for 6 out of 8 hrs-bingo we have a winner. I think they go back 15 yrs in your work history so being able to stand for long periods would probably be impossible. Because of your age they may not consider your education(see final sentence). Sitting for long periods probably is a problem also(sitting job requires sitting 6 out of 8 hrs). Sounds like you have a case. If you can't stand or sit-I don't see how education matters.