Structure
The iliolumbar ligament connects the lateral tip of the transverse process of the fifth lumbar vertebra (and sometimes L4) to the superior aspect of the posterior iliac crest and iliac fossa. This ligament travels laterally in two distinct groups of fibers, the upper and lower bands.
Function
The iliolumbar ligament contains strong fibers which support the stability of the pelvic girdle and limit the range of movement at the lumbosacral junction.
