[QUOTE= use your health insurance & see a sports-oriented Physical Therapist - you may find the solution is as simple as, for instance, making a conscious effort to extend your lower spine[/QUOTE]
+1
This worked for me - 58 and starting to have arghritis
and had frequent back pain for ~6 months - the PT gave me some stretch exercises, the key one for me being the "cobra" stretch 5 min 2x a day. After a few weeks of stretching and strengthening as directed, back pain went away...and the stretch changed my posture. Hope yours goes too... but as another poster said, have your back checked out by a specialist, my solution may not work for you. For me, a more upright position is worse for my back.