BOX6–3 HERNIATED DISC
The vertebrae are separated by discs of fibrous car-
tilage that act as cushions to absorb shock. An inter-
vertebral disc has a tough outer covering and a soft
center called the nucleus pulposus. Extreme pres-
sure on a disc may rupture the outer layer and force
the nucleus pulposus out. This may occur when a
person lifts a heavy object improperly, that is, using
the back rather than the legs and jerking upward,
which puts sudden, intense pressure on the spine.
Most often this affects discs in the lumbar region.
Although often called a “slipped disc,” the
affected disc is usually not moved out of position.
Box Figure 6–C Herniated disc. As a result of compression, a ruptured intervertebral disc puts pres-
sure on a spinal nerve.The terms herniated discorruptured discmore
accurately describe what happens. The nucleus pul-
posus is forced out, often posteriorly, where it puts
pressure on a spinal nerve. For this reason a herni-
ated disc may be very painful or impair function in
the muscles supplied by the nerve.
Healing of a herniated disc may occur naturally if
the damage is not severe and the person rests and
avoids activities that would further compress the
disc. Surgery may be required, however, to remove
the portion of the nucleus pulposus that is out of
place and disrupting nerve functioning.121