Linea Alba

linea alba

The linea alba is the vertical tendinous raphe formed by the decussating aponeuroses of the bilateral external oblique, internal oblique, and transversus abdominis muscles. It extends from the xiphoid process to the pubic symphysis, widening in the epigastrium and narrowing below the umbilicus. It provides structural midline continuity of the abdominal wall.

Anatomical Data

Boundaries & Contents

Location	Midline of the anterior abdominal wall, from the xiphoid process to the pubic symphysis
Boundaries	Above: xiphoid process Below: pubic symphysis and pubic crest On each side: medial edge of the rectus sheath Formed by interlacing aponeuroses of external oblique, internal oblique and transversus abdominis
Contents	Umbilical ring

Biomechanics

Function & Actions

Joins the abdominal muscles of both sides in the midline, acting as a central anchor; it widens in diastasis recti and is the site of midline incisions and epigastric hernias.

Clinical Relevance

Clinical Notes

Epigastric hernias preferentially occur through defects in the linea alba, typically between the xiphoid and umbilicus where the linea is widest. Diastasis recti is widening of the linea alba above the umbilicus from pregnancy or obesity, identifiable clinically as a midline ridge during abdominal curls. Primary closure of the linea alba in laparotomy must account for fascial quality to prevent incisional hernia.

Pathology

Common Injuries & Conditions

Epigastric Hernia

Peritoneal fat or bowel protrusion through a defect in the linea alba, producing a tender epigastric lump that is reducible and worsened by increased intra-abdominal pressure.

Diastasis Recti

Widening of the linea alba from repeated abdominal distension, particularly in pregnancy, producing a visible midline bulge without true herniation, managed with core rehabilitation.

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