Exercise - it works.
Six years ago I started on the RCAF's old 5BX program (a quick Google search will lead you to the booklet that describes it -- dead simple) and, in exchange for 11 minutes of exercise a day on an open floor, had the body I've always wanted within a year.
I've since moved on to weights and other gym-like stuff and have not had back pain in years.
It's so stupidly obvious I'm kicking myself for it now: If you have decent muscle to support all those bones and tendons up your back, they won't be straining themselves to the point of pain while supporting your body.
I do other exercises too: stationary cycling, rowing and treadmill with some weight work. All necessary because I enjoy food!
1) You can develop very strong lower back muscles (primarily the extensors), but don't challenge those muscles when they're nearing their endurance limit.
2) If your femurs are long relative to your tibia, don't try to force yourself to perform as heavy or with the same form and depth on squats, deadlifts, or cleans, as more normal folks. At low depth, your back will consistently be more parallel to the floor than upright, dramatically increasing shear across your spine.
Of course, it goes without saying that you shouldn't round your back excessively while bearing significant load, especially if it's far (horizontally) from your hips. It's not necessarily that a rounded back is automatically dangerous, but in general, if you're bracing your abdominal/back muscles (which will prevent rounding), you're less at risk of injury.
The only thing that has helped is exercise. Strengthening your back (especially lower) is probably going to help more than anything else. Squats and deadlifts in particular.
That being said, lifting weights is great for you, doesn't take much time (you can do a very complete job in 4 hours per week), and has significantly helped me with back pain.