Rectus Abdominis Muscle

Origin

The rectus abdominis muscle originates from the:

- pubic crest, via its lateral fibers;

- pubic symphysis, via its medial fibers.

Insertion

The fibers of the rectus abdominis muscle travel superiorly and insert onto the:

- xiphoid process;

- anterior aspects of the fifth to seventh costal cartilages.

Key Features & Anatomical Relations

The rectus abdominis muscle is one of the muscles of the abdomen. It is a long, strap-like type of skeletal muscle.

It is located:

- posterior to the pyramidalis muscle;

- medial to the external abdominal oblique, internal abdominal oblique and transversus abdominis muscles;

- lateral to the linea alba.

The rectus abdominis muscle:

- is broader superiorly than inferiorly;

- is surrounded by the rectus sheath;

- consists of three tendinous intersections, which attach to the anterior layer of the rectus sheath;

- contributes to the formation of the anterior abdominal wall.

Actions

The rectus abdominis muscle is involved in multiple actions:

- it flexes the trunk (Standring, 2016);

- it compresses and provides structural support to adjacent abdominal structures (Moore, Dalley and Agur, 2009).

List of Clinical Correlates

- Transverse rectus abdominis musculocutaneous (TRAM) flap

References

Moore, K. L., Dalley, A. F. and Agur, A. M. R. (2009) Clinically Oriented Anatomy. Lippincott Williams & Wilkins.

Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.

Actions

The rectus abdominis muscle is involved in multiple actions:

- it flexes the trunk (Standring, 2016);

- it compresses and provides structural support to adjacent abdominal structures (Moore, Dalley and Agur, 2009).