Bony landmark · Core

Linea alba

Linea alba

The linea alba is the fibrous seam running straight down the midline of the abdomen, from the tip of the breastbone to the pubic bone. It is not a bony feature at all: it is the line where the flat sheet-tendons of the abdominal muscles of both sides interweave and meet. The two columns of the rectus abdominis run in sleeves either side of it, and the obliques and transversus abdominis all pull into it — so it is what each half of the abdominal wall pulls against. It is also the seam that widens when the abdomen is stretched over time, as in pregnancy.