A third tendinous arch, the lateral arcuate ligament, is formed by a thickening in the fascia that covers the quadratus lumborum. It is attached medially to the transverse process of vertebra LI and laterally to rib XII (Fig. 4.144).
The medial and lateral arcuate ligaments serve as points of origin for some of the muscular components of the diaphragm.
Structures passing through or around the diaphragm