Ligaments
Three of the more important ligaments in the spine are the Ligamentum Flavum, Anterior Longitudinal Ligament and the Posterior Longitudinal Ligament.
- The Ligamentum Flavum forms a cover over the dura mater: a layer of tissue that protects the spinal cord. This ligament connects under the facet joints to create a small curtain over the posterior openings between the vertebrae.
- The Anterior Longitudinal Ligament attaches to the front (anterior) of each vertebra. This ligament runs up and down the spine (vertical or longitudinal).
- The Posterior Longitudinal Ligament runs up and down behind (posterior) the spine and inside the spinal canal.
Primary Spinal Ligaments Include:
Ligament | Spinal Region | Limits… |
---|---|---|
Alar | Axis skull | Head rotation & lateral flexion |
Anterior Atlantoaxial | Axis & Atlas | Extension |
Posterior Atlantoaxial | Axis & Atlas | Flexion |
Ligamentum Nuchae | Cervical | Flexion |
Anterior Longitudinal | Axis Sacrum | Extension & reinforces front of annulus fibrosis |
Posterior Longitudinal | Axis Sacrum | Flexion & reinforces back of annulus fibrosis |
Ligamentum Flavum | Axis Sacrum | Flexion |
Supraspinous | Thoracic & Lumbar | Flexion |
Interspinous | Lumbar | Flexion |
Intertransverse | Lumbar | Lateral flexion |
Iliolumbar | Sacroiliac joints | Stability & some motion |
Sacroiliac | Sacroiliac joints | Stability & some motion |
Sacrospinous | Sacroiliac joints | Stability & some motion |
Sacrotuberous | Sacroiliac joints | Stability & some motion |
Ligaments of the Back of the Cervical and Upper Thoracic Spine
1. Supraspinous Ligament (flexion) 2. Ligamentum Nuchae (fibrous membrane) |
Ligament Systems Atlas and Axis
As mentioned in the Vertebral Column, the Atlas (C1) and Axis (C2) are different
from the other spinal vertebrae. The upper cervical ligament system is especially
important in stabilizing the upper cervical spine from the skull to C2. Although
the cervical vertebrae are the smallest, the neck has the greatest range of
motion.
Occipitoatlantal Ligament Complex (Atlas)
These four ligaments run between the Occiput and the Atlas:
- Anterior Occipitoatlantal Ligament
- Posterior Occipitoatlantal Ligament
- Lateral Occipitoatlantal Ligaments (2)
Occipitoaxial Ligament Complex (Axis)
These four ligaments connect the Occiput to the Axis:
- Occipitoaxial Ligament
- Alar Ligaments (2)
- Apical Ligament
Altantoaxial Ligament Complex (Axis)
These four ligaments extend from the Atlas to the Axis:
- Anterior Atlantoaxial Ligament
- Posterior Atlantoaxial Ligament
- Lateral Ligaments (2)
Cruciate Ligament Complex
These ligaments help to stabilize the Atlantoaxial (Axis) complex:
- Transverse Ligaments
- Superior Longitudinal Fascicles
- Inferior Longitudinal Fascicles