There aren’t too many physical problems that can be caused by both doing something and doing nothing. Back pain is one of those rare conditions that fits into both categories.
Think about it. Back pain can be the result of any number of activities, from highly physical to barely moving. You can hurt your back playing a sport. You can harm it by carrying too much weight. You can injure it by lifting a heavy object without proper body mechanics. Some people have even tweaked their back walking or even just standing up. Years ago, professional baseball player Sammy Sosa, while with the Chicago Cubs, ended up on the disabled list, courtesy of a back injury incurred from a hard sneeze.