Have nagging chronic low back pain? Mostly likely you have scar tissue/adhesions at the attachment at one or more of the back muscles. When the small stability muscles are weak the large muscles take over the roll of stabilizing and moving your person.  In this altered environment the large muscles become chronically tight.  As those large muscles tighten they shorten as well, which pulls on the part that attaches to bone.  Eventually those muscle and tendons become damaged from the overuse.  At the site of muscle damage the body produces fibers that are harder and stiffer called scar tissue.  In a perfect world the tissue under the scar tissue can heal while being protected by the harder tissue.  In the case of chronic overuse the tissue remains under constant stress and more and more scar tissue to formed.  The scar tissue itself becomes a primary source of pain.