Strong Fitness Bodybuilding Girl With Abdominal Six-pack Belly Muscles

The abdominal wall is split into the posterior (back), lateral (sides), and anterioriet (front) walls.
• Muscles
The transversus abdominis muscle is flat and triangular, with its fibers running horizontally. It lies between the inner oblique and the underlying transversalis fascia. It originates from Poupart's ligament, the inner lip of the ilium, the lumbar fascia and the inner surface of the cartilages of the six lower ribs. It inserts into the linea alba behind the rectus abdominis.
The rectus abdominis muscles are long and flat. The muscle is crossed by three tendinous intersections called the linae transversae. The rectus abdominis is enclosed in a thick sheath formed by fibers from each of the three muscles of the lateral abdominal wall. They originate at the pubis bone, run up the abdomen on either side of the linea alba, and insert into the cartilages of the fifth, sixth, and seventh ribs.