The next group of muscles that make up the abdominals are the external oblique muscles. This pair of muscle are located on each side of the rectus abdominis. The muscle fibers of the external obliques run diagonally downward and inward from the lower ribs to the pelvis, forming the letter V. You can locate them by putting your hands in your coat pocket.
The external obliques originate at the fifth to twelfth ribs and insert into the iliac crest, the inguinal ligament, and the linea alba of the rectus abdominis.
The external oblique muscles allows flexion of the spine, rotation of the torso, sideways bending and compression of the abdomen.