Lumbar Spine Muscles Ilio-psoas Iliacus Psoas Major Minor medical education multimedia

http://www.medilaw.tv Lumbar Spine Muscles Ilio-psoas Iliacus Psoas Major Minor medical education multimedia. Shows the location and action of ilio-psoas.

1. ILIACUS
DESCRIPTION
Iliacus is a large, triangular muscle sheet. It is commonly combined with psoas major and psoas minor to form the iliopsoas.

ORIGIN
Iliacus originates from the superior two thirds of the concavity of the iliac fossa, the inner lip of the iliac crest, the ventral sacro-iliac and iliolumbar ligaments, and the upper surface of the lateral part of the sacrum.

INSERTION
Iliacus inserts primarily into the lateral side of the tendon of psoas major. Some fibres insert into the femur just inferior and anterior to the lesser trochanter.

INNERVATION
Iliacus is innervated by branches of the femoral nerve from L2 and L3 spinal nerves.

BLOOD SUPPLY
Iliacus is supplied by the iliac branch of iliolumbar artery, iliac branches of the obturator artery, lateral circumflex femoral artery, and the arteria profunda femoris.

ACTION
Iliacus flexes the hip joint.
Iliacus assists with external rotation and adduction of the hip.

FUNCTION
Iliacus works with psoas major. They are used to stabilise the trunk during sitting and standing.

Lumbar Spine Muscles Ilio-psoas Iliacus Psoas Major Minor medical education multimedia.

2. PSOAS MAJOR
DESCRIPTION
Psoas major is a long, thick, powerful muscle that descends along the pelvic brim, behind the inguinal ligament and in front of the capsule of the hip joint. The subtendinous iliac bursa separates the insertion tendon from the pubis and hip joint capsule.

ORIGIN
Psoas major originates from the anterior surfaces and lower borders of the transverse processes of all the lumbar vertebrae, from slips from adjacent vertebral bodies and their intervertebral disc starting from the lower margin of the body of the twelfth thoracic vertebrae and finishing on the upper margin of the body of the fifth lumbar vertebrae, and from tendinous arches between these slips.

INSERTION
Psoas major inserts into the lesser trochanter of the femur.

VARIATIONS
Psoas major sometimes has minor variations in its vertebral origins.

INNERVATION
Psoas major is innervated by ventral rami of the L1, L2, and L3 spinal nerves.

BLOOD SUPPLY
Psoas major is supplied by lumbar arteries 1 to 4, small branches from the renal artery, the common iliac artery, external iliac artery, and the lumbar branch of the iliolumbar artery. Sometimes it is also supplied by arteria lumbalis ima, the obturator artery and the medial circumflex femoral artery.

ACTION
Psoas major flexes the hip.
Psoas major can flex the lumbar spine anteriorly when both sides work together, or laterally when one side is active. This helps to stabilise the trunk on the thigh during standing and sitting.
Psoas major assists with external rotation of the femur.

FUNCTION
Psoas major works with iliacus and psoas minor, together known as iliopsoas.



3. PSOAS MINOR
DESCRIPTION
Psoas minor is a small weak muscle that lies anterior to psoas major.

ORIGIN
Psoas minor originates from the sides of the bodies of the twelfth thoracic and first lumbar vertebrae and the intervertebral disc between them.

INSERTION
Psoas minor inserts into the pecten pubis and the iliopectineal eminence, and laterally to the iliac fascia.

VARIATIONS
Psoas minor is often absent.

INNERVATION
Psoas minor is innervated by a branch from L1 spinal nerve.

BLOOD SUPPLY
Psoas minor is supplied by lumbar arteries, arteria lumbalis ima, the lumbar branch of the iliolumbar artery, and the common iliac artery. It is sometimes supplied by the obturator artery and the deep circumflex artery.

ACTION
Psoas minor assists in flexion and external rotation of the hip.
Psoas major assists with flexion of the lumbar spine anteriorly when both sides work together, or laterally when one side is active. This helps to stabilise the trunk on the thigh during standing and sitting.

FUNCTION
Psoas minor works with psoas major and iliacus, together known as iliopsoas.
Lumbar Spine Muscles Ilio-psoas Iliacus Psoas Major Minor medical education multimedia.

Category:

Education

Tags:

• Lumbar
• Spine
• Muscles
• Ilio-psoas
• Iliacus
• Psoas
• Major
• Minor
• medical
• education
• multimedia