|The ligaments connecting the fifth lumbar vertebra with the sacrum are similar to those which join the movable segments of the vertebral column with each otherviz.: 1. The continuation downward of the anterior and posterior longitudinal ligaments. 2. The intervertebral fibrocartilage, connecting the body of the fifth lumbar to that of the first sacral vertebra and forming an amphiarthrodial joint. 3. Ligamenta flava, uniting the laminæ of the fifth lumbar vertebra with those of the first sacral. 4. Capsules connecting the articular processes and forming a double arthrodia. 5. Inter- and supraspinal ligaments.
| On either side an additional ligament, the iliolumbar, connects the pelvis with the vertebral column.
|The Iliolumbar Ligament (ligamentum iliolumbale) (Fig. 319).The iliolumbar ligament is attached above to the lower and front part of the transverse process of the fifth lumbar vertebra. It radiates as it passes lateralward and is attached by two main bands to the pelvis. The lower bands run to the base of the sacrum, blending with the anterior sacroiliac ligament; the upper is attached to the crest of the ilium immediately in front of the sacroiliac articulation, and is continuous above with the lumbodorsal fascia. In front, it is in relation with the Psoas major; behind, with the muscles occupying the vertebral groove; above, with the Quadratus lumborum.