I've had severe low back pain from a horseback riding accident in 2005. I had it checked out (again) and my new doctor said it's not sciatica (like previous had said), it's a ligament sprain. From what I've read the pain from a sprain is usually resolved in a year. It's been many years and the pain hasn't subsided, more like become worse. Is it possible I have more than just a sprain?