There are a multitude of reasons for a stiff and tight back. Personally, I find sleeping on a different mattress or long periods of sitting as a culprit.
My history of low back pain stems from a condition known as spondylolisthesis. My L5 slipped out 1/4 inch when I was 17 and since then I have periodic back pain. At first, it was extremely painful and I could barely walk. Through proper exercise and strengthening, I have been able to minimize the pain on a day to day basis.
If you are experiencing stiffness and nerve pain associated with sciatica or piriformis syndrome, give nerve flossing a try. Nerve flossing is a natural exercise remedy that you can do from anywhere and it is used to gently mobilize irritated or compressed nerves.
Nerves run from your toes to your head and flossing involves synchronized movement on both ends of the body. In the below vides, the goal is to have the head and foot move in unison (this moves and glides the nerve like a rubber band).
Aim for 10 reps each side and go slow!
Here is the Beginner Version -
Here is the advanced version:
Try these periodically throughout the day and let us know what you think.