Iliolumbar ligament
Encyclopedia
The iliolumbar ligament is a strong ligament
passing from the tip of the transverse process of the fifth lumbar vertebra to the posterior part of the inner lip of the iliac crest
(upper margin of ilium
).
. Occasionally, a small ligamentous band stretches from the tip of the transverse process of the fourth vertebra down to the iliac crest behind the main ligament. Usually, fibrous strands are found between this latter process and the iliac crest, but these are only considered a true ligament when dense enough.
It radiates as it passes laterally 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.
assisted by the lateral lumbosacral ligament, and, like all other vertebral joints, by the posterior
and anterior longitudinal ligament
s, the ligamenta flava
, and the interspinous and supraspinous ligament
s.
Ligament
In anatomy, the term ligament is used to denote any of three types of structures. Most commonly, it refers to fibrous tissue that connects bones to other bones and is also known as articular ligament, articular larua, fibrous ligament, or true ligament.Ligament can also refer to:* Peritoneal...
passing from the tip of the transverse process of the fifth lumbar vertebra to the posterior part of the inner lip of the iliac crest
Iliac crest
-External links: - "Superficial muscles of the gluteal region and posterior thigh." - "Anterior Abdominal Wall: Osteology and Surface Anatomy " - "The Back, Posterior View" * *...
(upper margin of ilium
Ilium (bone)
The ilium is the uppermost and largest bone of the pelvis, and appears in most vertebrates including mammals and birds, but not bony fish. All reptiles have an ilium except snakes, although some snake species have a tiny bone which is considered to be an ilium.The name comes from the Latin ,...
).
Course
It forms the thickened lower border of two of the layers of the thoracolumbar fasciaThoracolumbar fascia
The thoracolumbar fascia is a deep investing membrane which covers the deep muscles of the back of the trunk. It is made up of three layers, anterior, middle, and posterior. The anterior layer is the thinnest and the posterior layer is the thickest. Two spaces are formed between these three...
. Occasionally, a small ligamentous band stretches from the tip of the transverse process of the fourth vertebra down to the iliac crest behind the main ligament. Usually, fibrous strands are found between this latter process and the iliac crest, but these are only considered a true ligament when dense enough.
It radiates as it passes laterally and is attached by two main bands to the pelvis
Pelvis
In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...
. The lower bands run to the base of the sacrum
Sacrum
In vertebrate anatomy the sacrum is a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx...
, blending with the anterior sacroiliac ligament
Anterior sacroiliac ligament
The anterior sacroiliac ligament consists of numerous thin bands, which connect the anterior surface of the lateral part of the sacrum to the margin of the auricular surface of the ilium and to the preauricular sulcus....
; 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.
Function
The ililumbar ligament strengthen the lumbosacral jointLumbosacral joint
The lumbosacral joint is a joint of the body, between the last lumbar vertebra and the first sacral segment of the spinal cord....
assisted by the lateral lumbosacral ligament, and, like all other vertebral joints, by the posterior
Posterior longitudinal ligament
The posterior longitudinal ligament is situated within the vertebral canal, and extends along the posterior surfaces of the bodies of the vertebræ, from the body of the axis, where it is continuous with the membrana tectoria, to the sacrum....
and anterior longitudinal ligament
Anterior longitudinal ligament
The anterior longitudinal ligament is a ligament that runs down the anterior surface of the spine. It traverses all of the vertebral bodies and intervertebral discs....
s, the ligamenta flava
Ligamenta flava
The ligamenta flava are ligaments which connect the laminae of adjacent vertebrae, all the way from the axis to the first segment of the sacrum...
, and the interspinous and supraspinous ligament
Supraspinous ligament
The supraspinal ligament is a strong fibrous cord, which connects together the apices of the spinous processes from the seventh cervical vertebra to the sacrum; at the points of attachment to the tips of the spinous processes fibrocartilage is developed in the ligament.It is thicker and broader in...
s.