Lumbar part of diaphragm

The lumbar part of the diaphragm refers to the posterior attachment of the diaphragm to the lumbar vertebrae.

The lumbar part of the diaphragm is primarily composed of two muscular crura, the right and left crura, and which originate from the anterolateral surfaces of the upper lumbar vertebrae and the intervertebral discs, and from the paired medial and lateral arcuate ligaments (ligaments previously termed as lumbocostal arches or Haller's arches).

The right crus is typically larger and longer, attaching to the bodies of the first three or four lumbar vertebrae, while the left crus attaches to the first two or three lumbar vertebrae.