One of the reasons you have lower back pain is due to tight muscles. This would include muscles in the lower and upper body. Remember, the muscles in your body are really just one big muscle.

What's happening in your back when it flares-up could be caused by tight muscle in your neck, shoulders, or even your feet. These muscles need to be stretched and lengthened in order to provide relief and prevent future flare-ups. The best stretches for your back, in my opinion, come from yoga. If you have never done Yoga to help your back, you should give it a try.

Strength Training:
When muscles are not used, they become weak. When they become weak, they have no durability. So when called upon to work overtime, they quickly fatigue and fail. That's never a good thing.

The body's response to this failure is to have the muscles, "spasm" in order to immobilize the area of the body that those muscles are designed to support and prevent injury. Kind of like the body's circuit breaker.

For example, if the muscles in your core can no longer support your lumbar spine, they signal the brain to "spasm" the muscles in your lower back and immobilize the area. This is the pain and stiffness you feel when your back goes out, thus protecting it from damage.