Quadratus Lumborum Muscle
Origin: Inferior border of the 12th rib
Insertion: Transverse processes of L1 to L4, the iliolumbar ligament, and the posterior third of the iliac crest
Actions: Lateral flexion of the lumbar spine
Innervation: Ventral primary rami of T12 to L3
Blood Supply: Branches from the lumbar artery
Primary Actions of the Quadratus Lumborum
1. Lateral rotation of the lumbar spine when acting unilaterally
Agonists:
- Iliocostalis lumborum
- Longissimus thoracis
- Psoas major
- External oblique
- Internal oblique
Antagonists: Same muscles on contralateral side
- Iliocostalis lumborum
- Longissimus thoracis
- Psoas major
- External oblique
- Internal oblique
The intertransversarii assist with lateral flexion of the lumbar spine
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Secondary Actions of the Quadratus Lumborum
1. Elevation of the pelvis when acting unilaterally
Agonists:
- Rectus abdominis
- Internal oblique
- External oblique
Antagonists: None
Muscle Pain Information: The quadratus lumborum muscle contributes to pain in the low back, buttock, hip, and groin.
An excellent book for those beginning the study of anatomy. Coloring helps memory retention.
For intermediary anatomy students learning skeletal and muscle structure.
For beginning and intermediary anatomy . Muscle overlays on the human body. Excellent visuals!
