How to tell if I have lower back problems.?

I was in a car accident just over a year ago and I broke my femur and had to have surgery to put a metal rod in my femur and I am going to have to have. I didnt have back problems until about a few months ago. could it be because of the car accident. It was on and off depending on what I did. I dont do anything to mess up my back. I dont work out the only thing I do is ride my bike around town. It seems to be the worst when I ride my bike and I love to ride my bike but I havent rode it very often since my femur healed. Could all of the limping have tweaked something in my back