It's almost certain you'll have back problems at one point or another if you're not doing anything relating to these 3 areas: cardiovascular exercise, strengthening and STRETCHING!
When it comes to lower back pain, it is usually what we do not do that cause the problems. Often people attribute sore back to a specific "event" — sure, while a particular movement might be "the straw that broke the camel's back," however, the stage for the injury has in most cases, been set long before the occurrence of the actual triggering event.
The simple act of bending forward to do normal, daily activities repeatedly over time is enough to aggravate your back if it is weak — never mind heavy work. This forward flexion we execute each day does not even have to be "loaded" (i.e. lifting something heavy) — damage can occur from the movement itself!
Also, here's another thing, if you're having back problems, chances are you're also tight and weak in your core area (abs, back, glutes, hip flexor), as well as, stiff in the hamstrings and calves. They are all connected to your back! If you don't learn to stretch properly, your back will eventually suffer.
Don't rely solely on external factors for temporary relief (i.e. massages, prescription drugs, chiro, physio, etc.). Instead, learn to empower yourself with permanent relief. This can only be achieved with the help of the earlier mentioned professionals, but adding to it your own initiative for regular light cardio, strength training, and STRETCHING! You can't perform one without the other two — they work best together!
Want to know more? Read: 9 Myths About Low Back Pain