Iliocostalis LumborumThe muscle indicated is the iliocostalis lumborum muscle, one of the erector spinae group of back muscles. The back muscles can be divided into three groups of muscles:
- Deep group
Origin: sacrum, iliac crest, spinous processes of lumbar vertebrae and thoracic vertebrae T11 and T12
Insertion: Inferior borders of lower 6/7 ribs
Innervation: Posterior branch of spinal nerve
Action: Unilateral contraction – flexes head to same side. Bilateral contraction – extension of vertebral columnLearn all about the anatomy of the superficial back muscles and the intermediate and deep back muscles.