My back issues stems from tight hamstrings. When my back flairs up it is always because my hamstrings are tight. I have to be very dedicated to stretching including the pic in your 1st post. My back was quite bad back in 2000. I could not sit for more then 10 min without being in significant pain. My Dr gave me pain medication and muscle relaxants which did nothing. The only thing that worked for me was Yoga and lots of stretching. Good luck to you. Back pain is no fun.