Degeneration is a process where wear and tear causes deterioration.
The disc is subjected to different types of stress as we use our back each day. The disc generally acts like a shock absorber. Bending over results in compression of the disc and also can cause the disc to bulge backwards towards the spinal canal and nerves. The facet joints must also shift to allow the bending to occur. The earliest changes that occur in the disc are tears in the annulus, the outer wall of the disc.