Origin: Transverse processes of C7 to T12vertebrae
Insertion: Superior surfaces of the ribs immediately inferior to the preceding vertebrae
Nerve: Dorsal rami - C8, T1, T2, T3, T4,T5, T6, T7, T8, T9, T10, T11
Action: Assists in elevation of the thoracic rib cage
The Levatores costarum, twelve in number on either side, are small tendinous and fleshy bundles, which arise from the ends of the transverse processes of the seventh cervical and upper eleven thoracic vertebrae; they pass obliquely downward and lateralward, like the fibers of the Intercostales externi, and each is inserted into the outer surface of the rib immediately below the vertebra from which it takes origin, between the tubercle and the angle (Levatores costarum breves). Each of the four lower muscles divides into two fasciculi, one of which is inserted as above described; the other passes down to the second rib below its origin (Levatores costarum longi).