The external oblique, which covers the front sides of the abdomen, is located on both sides of the rectus abdominis. The fibers run diagonally upward and sideward from the lower attachment on both sides of the abdomen and form a letter V when viewed from the front.
The external oblique originates (at the upper end) at the lower eight ribs.
Insertion is at the lower end at the front half of the ilium, the crest of the pubis, and the linea alba.
The external oblique muscles are responsible for rotation of the upper and lower trunk, lateral flexion, and flexion of the spine.