Rectus Abdominis

Joe Muscolino

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The rectus abdominis bilaterally. The external abdominal oblique has been ghosted in on the left side.

  • The rectus abdominis attaches from the crest and symphysis of the pubic bone to the xiphoid process of the sternum and the costal cartilages of ribs 5 through 7.



  • The rectus abdominis flexes and laterally flexes the trunk at the spinal joints.
  • It posteriorly tilts the pelvis at the lumbosacral joint.
  • The rectus abdominis also compresses the abdominal contents.


  1. The rectus abdominis is encased in the rectus sheath, which is created by the fibrous midline attachments of the other three anterior abdominal wall muscles: external abdominal oblique, internal abdominal oblique, and transversus abdominis.
  2. The rectus abdominis has horizontal fibrous bands known as tendinous inscriptions, which divide each rectus abdominis into four boxes.