Posture and Pain

I sat at my desk at work today, for a long time, hunched over, writing. I sat that way for too long, and when I stood up, realized it.  I took a quick break and a short walk.  I later went grocery shopping and I can still feel the lower back pain. I took some Aleve and put an analgesic patch on.  The next thing I am going to do is get on the elliptical and exercise for about 44 minutes.  (I am working up to 45 minutes, a day at a time, this week.) I know that will actually help.  I was ready to exercise about 45 minutes ago, but waited for the Aleve to kick in.