Name Iliocostalis lumborumPronunciation (il-e-o-kos-TA-lus lum-BOR-um) Origin/Proximal Attachment Common tendinous origin & medial iliac crest. Insertion/Distal Attachment Lower border of ribs (6), 7-12 Action/Relevance Extends, laterally flexes & assists in rotation of the vertebral column; can depress the ribs Innervation Lower thoracic & upper lumbar nerves | 
