Piraformis Stretches using a lacrosse ball:
click here for the video.
Please Note: Eventually this will feel so wonderful that you will want to "sit on your ball" often - please keep it down to, no more than, 5 minutes per day per side so that you do not bruise your piraformis or, even worse, irritate your sciatic nerve!
Basic Stretches for Everday
Computer & Desk Stretches
Arms, Hands & Shoulders
For general low back pain, the Yoga position called Child's Pose works very well to stretch your QL (Quadratus Lumborm) muscle as well as your Errector Spinae muscles. I recommend holding this pose for 5 minutes at a time. It is relaxing and therapeutic!