A large population of people are extension dominant in their low back due to many various reasons. This often causes over activation of lumbar extensors (low back muscles) and leads to degeneration of the joints over time. 
 

To avoid it, it is important to incorporate proper diaphragmatic breathing and evenly distribute the breath throughout the torso, especially during physical activity. This in many cases will take the tension out of tense low back muscles and disperse the load evenly through the trunk (core).

In the video, over activated low back muscles are outlined in red. (It is even more prevalent when person extends the hip while lacking good stabilization).  This is especially prevalent in surfers, dancers, people that wear high heals, tight hip flexors, etc. This translates into walking and running in the toe off phase of gait cycle. Some people may complain of pain or discomfort after such activities.
 

On the contrary, (example on the right) we learn to utilize diaphragmatic activation and breath to decompress the spine, reduce muscle tension and activate the core. This visibly creates a flatter looking back.

Step 1: lay on your belly with your forehead on the top your hands so that your back and neck are in a neutral position and you are able to breathe through your nose.

Step 2: Slowly breathe in through your nose and direct your breath down “into your shorts” and out “around your waist band”. You should feel a gradual release in your low back in a form of a slight stretch.

TIP: Use a slight activation of your abdomen against the surface you are laying on. This should further relax the low back.

CAUTION: Stop if you experience any increase in symptoms. Always start by performing the exercise gently and gradually increase activation. Exercise is medicine and not every type of medicine is right for everyone so consult with your doctor.