Try this move, Mr. "I'm-So-Coordinated" man:  drop down onto all fours and do a cat-cow maneuver (that's the one where you alternately arch and round your back).  Do a few reps, then hold the arched 'cow' position where the head and butt are up and the chest and belly are towards the floor.  Maintaining the arch in your lower back, rock backwards towards your feet as if you were going to sit on your heels. 

How did you do?  If you're like a lot of people, you may have had trouble maintaining the lower-back arch when you rocked backwards. 

You might be inclined to say, "Who cares?" but hang on a second, Devil-May-Care-McGee:  if your lower back rounded up when you sat back, chances are good your hips and pelvis are essentially glued together. 

If you've got a gummed-up hip joint, it means your lower-back is pretty much moving whenever your hips do:  walking, sitting, running, whatever.  And if your lower-back is twisting and turning and rocking and rolling to compensate for the immobility of your hip joints, well--that means low-back trouble--if not now, then soon.

So take some time to mobilize your hips.  It's easy--you should be mobilizing the hips as part of a warm-up anyway.  You can practice the test described above for this; also effective is the posted lunge, which is like regular lunges except you keep your back leg locked and your back foot turned at a 45 degree angle outward, rather like a warrior stance in yoga or a front stance in the martial arts (the photo below shows the former; adding the arms as pictured improves thoracic mobility as well--the subject of another post).  Sink up and down into the front hip, keeping the back leg locked out forcefully and trying to get yourself a little lower each rep.

Make sense?  All part of my one-man crusade to abolish back pain from the Western World...