Name

Longissimus Thoracis

Pronunciation

(lon-GIS-I-mus tho-RA-sus)

Origin/Proximal Attachment

Transverse processes of lumbar vertebrae; intermediate continuation of erector spinae

Insertion/Distal Attachment

Transverse processes of all thoracic vertebrae; lower 9 or10 ribs between tubercles & angles; transverse processes of upper lumbar vertebrae

Action/Relevance

Extends & laterally flexes vertebral column; can depress ribs

Innervation

Thoracic & lumbar nerves