This is one exercise you should never do and if you are doing it, stop.
It's commonly referred to as "superman" and is performed widely (the image source is the U.S. Coast Guard) in the armed services, sports teams, and unfortunately, with people who have lower back pain. It's regarded as a "core" exercise and used to "strengthen" your back and core muscles.
Why am I against it? Two reasons.
First, the compression created in your spine by this exercise exceeds 1300 lbs. of force. Anything over about 740 lbs. correlates highly with more lower back injury and pain according to the National Institute for Occupational Safety and Health (NIOSH)). This level of force can damage ligaments, joint surfaces and even rupture your disc.
Second, other than Clark Kent, who does this in everyday life? Of course, there is an argument that sometimes you have to perform exercises that are not terribly functional because the muscles are too weak to support the movement or position (e.g. about the only reason people with shoulder pain should consider the "open the coat" or external rotation exercise). So, if you want to challenge your spinal muscles, perform a drill that is not too functional but does strengthen your muscles, and not risk injury to the other tissues in your spine, read this article (another exercise you shouldn't do either). Near the end of the piece, I suggest something you can do easily and safely.
Make today count.