Anatomy
One of the intrinsic muscles of the back.
Consists of iliocostalis cervicus, thoracis and lumborum.
Iliocostalis cervicis:
Origin: Angles of 3rd to 6th ribs.
Insertion: Transverse processes of C4 to C6.
Iliocostalis thoracis:
Origin: Angles of 7th to 12th ribs.
Insertion: Angles of 1st to 6th ribs.
Iliocostalis lumborum:
Origin: Iliac crest, sacrum and spinous process of lumbar and lower two thoracic vertebrae.
Insertion: Angles of 5th to 12th ribs.
Key Relations:
Most lateral of erector spinae group. In essence has a common tendon of origin and is associated with the ribs.
Functions
-Working synergistically and bilaterally with longissimus and spinalis, acts to extend the vertebral column. If used correctly, responsible for good posture.
-Acting unilaterally with longissimus and spinalis, acts to laterally flex the spine on the ipsilateral side.
Supply
Nerve Supply:
Dorsal rami of segmental spinal nerves.
Blood Supply:
-Intercostal arteries
-Lumbar arteries.
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