Pain is nature's way of letting us know something isn't right, that we should slow down and pay attention. Of course we all suffer from various pain and it should never be ignored. It is our body's way of telling us to back off or we could injure ourselves more. In most cases back pain can be avoided by simply taking a break from what ever repetitive activity we may be doing.
Say you are doing some yard work, raking leaves for example. You've been at it for an hour and the progress is coming along nicely, then a sharp pain hits your lower back. But wait, you are almost done! One more pile and it will be finished and you can go inside and plop down on the couch under the breeze of the ceiling fan. Most of us will just try to ignore the pain and push on until the task is done and wake up to regret it in the morning.
Of course you really don't even have to be doing anything for pain to creep up your back or into your shoulders. Many people with desk jobs who sit at the computer all day end up with lower back pain just from not getting up and giving themselves a quick break. We've all gotten so far into our work only to look up and realized it's been four hours since we've been out of our chair.
Experts will tell you, it is always best to take small breaks from work and move around, take a little walk and stretch. Just by changing your position you will improve your circulation and give your muscles a much needed break. When you start to feel stiffness your body is trying to say "Hey! Let's take a break!" Your body will definitely thank you later.