1. Home
  2. Health
  3. Anatomy
  4. Muscles (muscular system)

New publications

The quadriceps lumborum muscle

Author: Alexey Portnov, family doctor
Date created: 03.04.2011
Last reviewed: 04.07.2025

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 ]