The spinal vertebrae are separated by cartilage disks filled with a gelatinous substance, that provide cushioning to the spinal column. These disks may move out of place or rupture from trauma or strain, especially if degenerative changes have occurred in the disk. When the disk moves out of place nerve roots (large nerves that branch out from the spinal cord) may become compressed resulting in neurological symptoms, such as pain, sensory and motor changes.
Update Date 4/16/2013
Updated by: C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.