Anatomy - Ligaments

Anterior longitudinal ligamentPosterior longitudinal ligamentInterspinous ligamentSupraspinous ligamentLigamentum flavumLigamentum nuchaeIntertransverse ligament

Superiorly - to anterior tubercle of atlas (C1) - continuour above with anterior atlanto-occipital membrane
all the way down - attaches to vertebral bodies / discs
Inferiorly - terminates by spreading over pelvic surface of upper part of sacrum
function - limits hyperextension of the spine restrains forward movement of one vertebrae over another

Superiorly - body of C2, continuous with tectorial membrane
Inferiorly - posterior surface of sacrum
All the way down - attaches only to discs and adjacent area of vertebrae - separated by body by interval (basivertebral vein)
Function - resists flexion of spine. Not as strong as anterior longitudinal ligament.

Attaches spinous process to adjacent spinous process - along entire length of spine
Function - resists flexion and excessive rotation.
Insignificant at cervical levels. More lower down.

Connecting tips of TPS. Continuous with posterior edge of interspinous ligament.
In cervical region, merges with / becomes replaced by nuchal ligament.

From SP of C7 to external occipital protruberance and crest.
Deep part of ligament attaches to posterior tubercle of C1 and SPs of all cervical vertebrae.
Function - provides muscle attachments without limiting extension of neck (which long SPs would)

Between adjacent TPs.Tend to be absent superiorly / replaced by intertransversarii. More obvious in lumbar region.Function - resists sidebending and rotation.

Between laminae of adjacent vertebrae - from C1 / C2 down to L4 / L5. From anterior lower border of lamina above - to posterior upper border of lamina below.
Yellow - elastic tissue. Only true elastic ligament.
Function - postural? aid return to upright position from flexion. Elastic - permits separation of laminae during flexion.

Transverse ligament of atlasAlar ligaments(transverse also called 'cruciform ligament' - has vertical portion above (to occiput) and below (to C2))Above C1 - anterior longitudinal ligament = anterior atlanto-occipital membrane. Posterior longitudinal ligament = tectorial membrane.

Holds dens in position - on posterior surface of anterior arch of C1attaches to lateral masses of C1

Attachments - dens, medial surfaces of occipital condyles superiorly. Function - resists excessive rotation of the head and C1 relative to C2

Interosseous sacroiliac ligamentAnterior sacroiliac ligamentPosterior sacroiliac ligament (long and short)Sacrotuberous ligamentSacrospinous ligamentSacrococcygeal ligaments (posterior, anterior, lateral) - longitudinal fibres, completely surround joint

Immediately postero-superior to sacroiliac joint (fibrous part of joint)Very strong.

From ala / anterior surface of sacrum to ilium.Not as strong as posterior ligament.

Covers the interosseous sacroiliac ligament.Short fibres superiorly - from sacrum to iliac tuberosity (same place as interosseous ligament)Long fibres - run almost vertically downwards from PSIS to sacrum.Arranged to resist downward movement of the sacrum with respect to the ilium (and nutation)