16 years ago I fell down a flight of steps, I was off my feet for a few days, but never got it checked out. Ever since my back has gotten gradually worse. I get severe pain right at the base of my spine, when standing for 10 mins or more. It then gradually extends to my left hand side to my hip. In bed if I roll on to my back, it s like something has clicked, and I m unable to move. I have to call for help, to pull me up, in screaming pain. Also whilst having bowl movements, I get pins and needles down my legs to the tips of my toes. Any idea what it could be