What Causes Pain In The Lower Back And Legs?

I am a 65 yr old relatively active woman. I walk and swim as primary exercise. Recently my lower back has been really acting up and the sides of my legs, from the hip to the knee are in constant awareness due to pain. I ve recently considered that my arch in my shoe is not supporting me so I remedied that today. We shall see. I m finding myself taking Ibuprophen at night before going to sleep and yet again during the day. There is family history of arthritis and while I ve avoided it this long I m wondering if it might not be my turn.