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The small lumbar muscle
Last reviewed: 07.07.2025
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The small lumbar muscle (m.psoas minor) is inconstant, absent in 40% of cases. It originates on the intervertebral disc and the adjacent edges of the bodies of the 12th thoracic and 1st lumbar vertebrae. The muscle is located on the anterior surface of the large lumbar muscle, fused with the fascia covering it. The thin belly of this muscle passes into a long tendon, which is attached to the arcuate line of the ilium and to the iliopectineal eminence. Some of the bundles of the tendon of this muscle are woven into the iliac fascia and into the iliopectineal arch.
Function of the psoas minor muscle: It tightens the iliac fascia, increasing support for the iliopsoas muscle.
Innervation of the lumbar minor muscle: muscular branches of the lumbar plexus (LI- LIV).
Blood supply of the psoas minor muscle: lumbar arteries.
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