The disk acts as a shock absorber between the bones in the neck. In cervical disk degeneration (which typically occurs in people age 40 years and older), the normal gelatin-like center of the disk degenerates and the space between the vertebrae narrows. As the disk space narrows, added stress is applied to the joints of the spine causing further wear and degenerative disease. The cervical disk may also protrude and put pressure on the spinal cord or nerve roots when the rim of the disk weakens. This is known as a herniated cervical disk.
^ Jump up to: a b Palmer DD (1910). The Chiropractor's Adjuster: Text-book of the Science, Art and Philosophy of Chiropractic for Students and Practitioners. Portland, OR: Portland Printing House Co. OCLC 17205743. A subluxated vertebra ... is the cause of 95 percent of all diseases ... The other five percent is caused by displaced joints other than those of the vertebral column.

Chiropractors use hands-on spinal manipulation and other alternative treatments, the theory being that proper alignment of the body's musculoskeletal structure, particularly the spine, will enable the body to heal itself without surgery or medication. Manipulation is used to restore mobility to joints restricted by tissue injury caused by a traumatic event, such as falling, or repetitive stress, such as sitting without proper back support.