What causes my lower back to have a grinding noise if I lay on my side but turn my back only so that it is on the floor? I then raise the bottom leg up as an exercise and with each raise you can literally hear my spine grind. There is no pain, just a scrubbing noise.
Hi, If what you describe is painless then, it is not likely that you are suffering from any significant arthritic degenerative disease responsible for the sounds especially if you are able to rotate your spine in the fashion you mention and raise the leg.  The noises you hear could be the sliding of tendons and ligaments over each other or over edges of vertebral bodies as you raise the leg since the rotation of the spine places the transverse processes at 90 degrees to normal which allows tendon gliding to occur over a different base skeletal structure.  Again, so long pain is not an element or manifestation of this activity then, I see it as a good thing since you are obviously demonstrating nice flexibility in your thoracolumbar spine. I would continue using these maneuvers to keep things limber. Hope I have answered your query. Let me know if I can assist you further. r. Darius Safari, Neurologist