The musculoskeletal abdominal wall is mainly formed by muscle, and partly by bone.

The skeletal elements of the abdominal wall are:

• All five lumbar vertebrae and intervertebral discs between them;
• Superior extended parts of the pelvic bones;
• Skeletal elements of the inferior thoracic wall, including the costal margin, 12th rib, the end of 11th rib, and the xiphoid process.

The abdominal wall can be divided into anterolateral and posterior portions.

Anteriorly, the rectus abdominis muscle on each side extends between the inferior thoracic wall and the pelvic wall. The lateral parts of the abdominal wall are formed mainly by three layers of muscles: transversus abdominis, internal oblique, external oblique. These muscles are in similar orientation to the intercostal muscles of the thorax.

The posterior part of the abdominal wall is reinforced by the following muscles located lateral to the vertebral column: the quadratus lumborum, the psoas major, and the iliacus muscles, as well as the psoas minor.