As someone who suffered from knife-in-the-back, nausea inducing, immobilizing back pain for years, I feel your agony. Like Blast said, Yoga is gold for the back. They often have classes devoted specifically to lower back therapy. I'd also recommend a good Osteopath. If you haven't already, I highly recommend you pinpiont the source of the pain and what brings on the muscle spasms or inflamation (usually something related to unstretched piriformis/hamstrings and unconditioned abdominal muscles). After years of debilitating pain, X-rays, top orthopedic surgeons, costly physical therapy, I was finally shown simple stetches and exercises that has kept my back spasm-free (pain free) for 4 years now. Good luck.