Yes.I have a dull pain in my left lower back.  I first thought I just over did it while working on my car after an afternoon motorcycle ride.  I have no pain when sleeping, ie, nothing is waking me up.  When I first get up, no pain, but it sets in after moving around for about a half hour.  It comes and goes through the day.  If I set in a comfortable chair (like a lazyboy), the pain subsides, but comes back when I start to move around.   Sitting in the car is a little tricky since sometimes I have the pain.  If I lean a little to the right, it subsides.
Dear patient your symptoms points towards diagnosis of mechanical backache reason being muscle spasm or instability of lumbar spine. I would advise X-ray of lumbosacral spine anteroposterior and lateral views to go firm diagnosis. Start tab moral 4\u00a0mg twice a day with tab diclofenac sodium 50 mg twice a day for 5 days. Take rest on hard bed. If X-ray is abnormal you need to visit orthopedic surgeon nearby you.