Lumbar Spine Anatomy

Question 1

Lumbar Spine: Joints

Answer 1

5 pairs of facets
Diarthrodial joints consist of superior and inferior facets and a capsule.
Facets carry 20% of the load.

Question 2

Lumbar Spine: Facet Joints Function

Answer 2

Frontal plane orientation provides restriction from anterior shear.
Rotation is limited and facets control : flexion, extension and sidebend (lateral flexion).

Question 3

Lumbar Spine: Facet Joints Orientation

Answer 3

Superior articulating process face medially and posteriorly.
Inferior articulating process face laterally and anteriorly.

Question 4

Lumbar Spine: Open and Closed Packed Position

Answer 4

Open Pack Position: midway between flexion and extension.
Closed Pack Position: extension.

Question 5

Lumbar Spine: Ligaments

Answer 5

Anterior longitudinal ligament (ALL)
Posterior longitudinal ligament (PLL)
- both ALL + PLL are taut in either flexion or extension

Question 6

Lumbar Spine: Pelvis Ligaments

Answer 6

Iliolumbar ligmanet: helps stabilize L5 with the ilium to prevent anterior displacement of L5.