The linea alba (Latin for: white line) is a strong fibrous midline structure[1] of the anterior abdominal wall[2] situated between the two recti abdominis muscles (one on either side).

The umbilicus (navel) is a defect in the linea alba through which foetal umbilical vessels pass before birth.

[1] The linea alba is formed by the union of aponeuroses (of the muscles of the anterior abdominal wall[2]) that collectively make up the rectus sheath.

[citation needed] In sufficiently muscular individuals, its presence can be seen on the skin, forming the depression between the left and right halves of a "six pack".

[citation needed] The linea alba stabilizes the anterior abdominal wall, as it balances contractile forces from the muscles attached to it.