Fibromyalgia Support Group
You're not alone in your pain. Fibromyalgia is a condition that can be difficult to diagnose and manage. If you're trying to cope with pain throughout your body, sleep problems, general fatigue, or other common fibromyalgia symptoms, you're in the right place. The community is here for you to talk about therapies and share your challenges.

Be sure to lay flat on your back and reach your arms way up and stretch those back muscles. Fold you legs up and bring you knees up to stretch your back. Make sure you work on good posture while sitting down.
Stretch from side to side slowly. Raise your shoulders up,push them back, then down, repeat all of these 10 x each. That should help with relaxing your back. Just good posture makes a difference also.
http://www.trueback.com/index2.php?SID=GRANTGZT
I am not making any claims on this product. however I own one and use it and I have scoliosis, and chronic neck and back pain for several years and it has helped me.
Also when I sit, or stand or walk too much my muscles sieze up on me big time. When I go to the mall for example, I have to be in a wheelchair. I walked it one time and there was hell to pay afterwards.
best wishes