Medical expert of the article

Rheumatologist

New publications

The quadriceps lumborum muscle

Alexey Kryvenko, medical expert
Last reviewed: 04.07.2025

All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.

We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.

If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.

The quadratus lumborum muscle (m. quadratus lumborum) is located lateral to the transverse processes of the lumbar vertebrae. It originates on the iliac crest, iliolumbar ligament, and transverse processes of the lower lumbar vertebrae. It is attached to the lower edge of the 12th rib and the transverse processes of the upper lumbar vertebrae. The lateral part of the muscle passes obliquely upward and medially. The muscle is covered at the back by the deep plate of the lumbothacral fascia. The psoas major muscle is located at the medial part of the quadratus lumborum muscle, and at the back is the origin of the muscle that straightens the trunk.

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

Function of the quadratus lumborum muscle

With bilateral contraction, it helps to keep the spine in a vertical position; with unilateral contraction, it tilts the spine to its side, pulls the 12th rib downwards together with the muscle that straightens the trunk and the abdominal muscles.

Innervation of the quadratus lumborum muscle

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

Blood supply of the quadratus lumborum muscle

Lumbar arteries, subcostal and iliolumbar arteries.

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