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Psoas major muscle
The psoas major and nearby muscles
Horizontal disposition of the peritoneum in the lower part of the abdomen. (Psoas major labeled at bottom left.)
Latin	m. psoas major
Gray's	subject #127 467
Origin:	lower spine
Insertion:	in the lesser trochanter of the femur
Artery:	lumbar branch of iliolumbar artery
Nerve:	Lumbar plexus via anterior branches of L2-L4 nerves
Action:	flexes and rotates laterally thigh
Antagonist:	Gluteus maximus
MeSH	Psoas+Muscles
Dorlands/Elsevier	m_22/12550274

The Psoas major is a long fusiform muscle placed on the side of the lumbar region of the vertebral column and brim of the lesser pelvis.

Contents 1 Location 1.1 Origin 1.2 Insertion 2 Function 3 Significance in Western Cuisine 4 Arts, Spirituality 5 See also 6 Additional images 7 External links

It arises:

• (1) from the anterior surfaces of the bases and lower borders of the transverse processes of all the lumbar vertebrae
• (2) from the sides of the bodies and the corresponding intervertebral fibrocartilages of the last thoracic and all the lumbar vertebrae by five slips, each of which is attached to the adjacent upper and lower margins of two vertebrae, and to the intervertebral fibrocartilage;
• (3) from a series of tendinous arches which extend across the constricted parts of the bodies of the lumbar vertebrae between the previous slips; the lumbar arteries and veins, and filaments from the sympathetic trunk pass beneath these tendinous arches.

The muscle proceeds downward across the brim of the lesser pelvis, and diminishing gradually in size, passes beneath the inguinal ligament and in front of the capsule of the hip-joint and ends in a tendon; the tendon receives nearly the whole of the fibers of the Iliacus and is inserted into the lesser trochanter of the femur.

A large bursa which may communicate with the cavity of the hip-joint, separates the tendon from the pubis and the capsule of the joint.

It forms part of a group of muscles called the hip flexors, whose action is primarily to lift the upper leg towards the body when the body is fixed or to pull the body towards the leg when the leg is fixed.

For example, when doing a sit up that brings the torso (including the lower back) away from the ground and towards the front of the leg, the hip flexors (including the iliopsoas) will flex the spine upon the pelvis.

Based on the anatomy and physiology of a cow, this muscle is the tenderloin, and tends not to be called upon to do a lot of work, thus it remains underdeveloped, resulting in a cut of meat that is known as the most tender. It forms the basis for several succulent dishes, including chateaubriand, filet mignon and Beef Wellington.

Other meat cuts in this area of the cow's body include the sirloin and the top sirloin.

Often of high significance in practice such as yoga, pilates, martial arts etc.

Being the only actual muscular connection between body and legs, makes efficient and controlled usage of this muscle very important in terms of finding ones strength, balance, and grounding.

Most forms of lunge will engage and stretch the psoas. Half- and full-lotus positions both stretch and elongate the psoas muscle and hip flexors in general.

Essential for proper lumbar, sacral and spinal support, alignment and control.

• Hip flexor
• Psoas minor muscle
• Iliacus

Right femur. Anterior surface.	Diagram of a transverse section of the posterior abdominal wall, to show the disposition of the lumbodorsal fascia.	The diaphragm. Under surface.	Muscles of the iliac and anterior femoral regions.
The arteries of the pelvis.	The relations of the femoral and abdominal inguinal rings, seen from within the abdomen. Right side.	The thoracic and right lymphatic ducts.	The lumbar plexus and its branches.
Nerves of the right lower extremity. Front view.	Sacral plexus of the right side.	Transverse section, showing the relations of the capsule of the kidney.

• -1261436848 at GPnotebook
• LUC psmj
• SUNY Labs 40:16-0101 - "Posterior Abdominal Wall: Muscles of the Posterior Abdominal Wall"
• SUNY Anatomy Image 8916
• Cross section at UV pelvis/pelvis-e12-2

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.

v • d • e List of muscles of lower limbs
ILIAC REGION/ILIOPSOAS	psoas major/psoas minor - iliacus
BUTTOCKS	gluteals: (maximus, medius, minimus) - tensor fasciae latae lateral rotator group: piriformis - obturator externus/obturator internus - inferior gemellus/superior gemellus - quadratus femoris
THIGH	anterior compartment: sartorius - quadriceps (rectus femoris, vastus lateralis, vastus intermedius, vastus medialis) - articularis genu posterior compartment/hamstring: biceps femoris - semitendinosus, semimembranosus medial compartment: gracilis - pectineus - adductor (brevis, longus, magnus)
LEG	anterior compartment: tibialis anterior - extensor hallucis longus - extensor digitorum longus - fibularis tertius posterior compartment: superficial - calf/triceps surae (gastrocnemius, soleus) - plantaris - deep - popliteus - tarsal tunnel (flexor hallucis longus, flexor digitorum longus, tibialis posterior) lateral compartment: fibularis muscles (longus, brevis)
FOOT	dorsal - extensor digitorum brevis - extensor hallucis brevis plantar - 1st layer (abductor hallucis, flexor digitorum brevis, abductor digiti minimi) - 2nd layer (quadratus plantae, lumbrical muscle) - 3rd layer (flexor hallucis brevis, adductor hallucis - flexor digiti minimi brevis) - 4th layer (dorsal interossei, plantar interossei)