slipped disk

This applies to an abnormality of an intervertebral disc in the spine. These discs are cushions of cartilage acting as shock absorbers between the bodies of the vertebrae that comprise the spinal column. They are therefore subject to considerable pressure, especially those in the lumbar spine, and these pressures are increased when a person lifts heavy weights. The discs are firmly fused to the vertebral bodies above and below, and the popular term is misleading — in suggesting that they are mobile structures that could slip out of place, and by implication could be ‘put back’ by manipulation or surgery. Rather, the discs can degenerate, a process that can be accelerated by repeated strains. Degenerated discs protrude and can press on spinal nerve roots or on the spinal cord, causing pain, with associated muscular spasm and sometimes weakness of the muscles of the arm, or of the leg, according to whether cervical or lumbar discs are affected. Such protrusions may require surgical removal. Only occasionally does acute injury tear part of an abnormal disc and release a loose fragment; this also may compress nervous structures and need to be removed.

— Bryan Jennett

See also spinal column.

A misnomer. Discs are firmly wedged between vertebrae and cannot slip (see prolapsed intervertebral disc).

A misnomer; discs do not slip, they herniate or rupture (see prolapsed intervertebral disc).