Introduction to the remarkable Lumbar Disc

The lumbar disc consists of 3 parts

  • Nucleus Pulposus (jelly portion in middle)
  • Annulus fibrosus (fibrinous outer portion)
  • Cartilaginous Endplates (attachment to bone above and below)


Lumbar Disc

The disc material in the Spine comprises 20-33% of the entire height of the Vertebral Column

Which is why we lose height as we get older and our discs degenerate

The disc is primarily exposed to compression forces but can also be subjected to tensile, axial rotation & lateral bending forces

Lumbar Disc

When sitting, the lumbar disc can be exposed to > 3 times the weight of the trunk.

Patients with degenerative disc disease oftentimes cannot sit for extended periods of time

Activities such as Running or Jumping can result in loads on the disc > 2X body weight.

The discs undergo normal age-related change as soon as the late teens or early 20’s

Lumbar Disc