The Musculus obliquus externus abdominis (lat. for „outer oblique abdominal muscle“) originates alternately with the spike of the Musculus serratus anterior and the Musculus latissimus dorsi from the fifth to the twelfth rip. It pulls with its abdominal tendon (Crus mediale) to the Linea alba and with the pelvic tendon (Crus laterale) to the ilium.

Lumbar Spine (LS)

M. Obliquus Abdominis Externus

5. to 12. Rip
Linea alba, Lig. inguinale, Crista iliaca, Tuberculum pubicum
Flexion an rotation of the trunk , Exspiration
Nervi intercostales (Th5 – 11), Nervus subcostalis