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)
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
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