The degenerative model of back pain describes a chain reaction of changes.

• At first the nucleus weakens, tears, and scars.
• As disc height decreases, the vertebrae move closer together.
• This puts pressure on the facet joints, which can cause them to become arthritic.
• Changes in the ligaments, discs, and facet joints can cause the spinal segment to become loose and unstable.
• Bone spurs form on the vertebrae.
• The nucleus may squeeze (herniate) through the weakened annulus.

Mechanical pain comes from wear and tear on the parts of the spine.

• It’s like a machine that is wearing out.
• It usually gets worse with activity and eases with rest.
• The pain rarely goes down past the knee.
• It usually doesn't cause weakness or numbness.

Neurogenic pain comes from a nerve injury.

• It occurs when spinal nerves are inflamed, squeezed, or pinched.
• It can cause pain and symptoms that affect structures away from the spine.

Neurogenic pain is more concerning than mechanical pain.

• Neurogenic pain involves the spinal nerves and can lead to weakness and numbness in the legs.
• Mechanical pain usually doesn't affect the nerves.