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Square lumbar muscle

Alexey Portnov, medical expert
Last reviewed: 23.04.2024

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The square muscle of the waist (m. Quadratus lumborum) is located at the side of the transverse processes of the lumbar vertebrae. It begins on the iliac crest, ilio-lumbar ligament and on the transverse processes of the lower lumbar vertebrae. It is attached to the lower edge of the XII rib and to the transverse processes of the upper lumbar vertebrae. The lateral part of the muscle passes obliquely upward and medially. The muscle behind is covered with a deep plate of the lumbosacral fascia. At the medial part of the square muscle of the waist is a large lumbar muscle, and behind - the beginning of the muscle, straightening the trunk.

trusted-source [1], [2], [3]

The function of the square muscle of the waist

With two-sided cutting helps to keep the spine in an upright position, with one-sided cutting tilts the spine to its side, pulls the XII rib downward along with the muscle that straightens the trunk, and the muscles of the abdominal press.

Innervation of the square muscle of the lower back

Muscular branches of the lumbar plexus (ThXII, LI-II).

Blood supply of the lumbar muscle

Lumbar arteries, subcostal and ilio-lumbar arteries.

trusted-source [4], [5], [6],