Diagram of the Rectus Abdominis

Rectus Abdominis: Origin, Insertion, Action

Origin: Pubic crest and the pubic symphysis
Insertion: The fifth to seventh costal cartilages, and the inferomedial costal margin and posterior aspect of the xiphoid process of the sternum
Actions: Flexion of the vertebral column
Innervation: Ventral Primary rami of (T7 to T12)
Blood Supply: Muscular branches from the superior and inferior epigastric arteries Rectus Abdominis Muscle Origin, Insertion, Action, Innervation

For more information see: Rectus Abdominis Muscle: Mid and Low Back, Abdominal, Heartburn, Testicular Pain 


Rectus Abdominis Actions With Agonists and Antagonists

Primary Actions of the Rectus Abdominis

1. Flexion of the thoracic spine when acting bilaterally

  Agonists: None


  • Iliocostalis cervicis
  • Iliocostalis thoracics
  • Iliocostalis lumborum
  • Longissimus cervicis
  • Longissimus thoracics
  • Spinalis thoracics
  • Semispinalis cervicis

Note: Internal oblique, external oblique, and psoas major assist with flexion of the thoracic spine.

2. Flexion of the lumber spine when acting bilaterally

Agonists: None

  • Iliocostalis lumborum
  • Longissimus thoracics
  • Spinalis thoracics

Note: Internal oblique, external oblique, and psoas major assist with flexion of the thoracic spine.

Secondary Actions of the Rectus Abdominis

1. Assists with forced expiration


  • Serratus posterior inferior
  • Transversus Abdominis


  • Serratus posterior superior
  • Levatores costarum breve
  • Levatores costarum longi

Note: The internal and external obliques also assist with forced expiration.

Recommended Anatomy Books:

The Anatomy Coloring Book is one of the best study and reference books for beginning anatomy students. The diagrams are clearly labeled and allow you to see the relationship and placement of the various structures of the body. You will also be surprised at how the act of coloring will help with recall. But this is not just a beginner’s book, it is also great for practitioners and therapists to have on hand to use with clients and patients to use as a visual reference.

The Trail Guide To The Body is another excellent book to help you learn the musculature of the human body. Though the book is geared toward massage therapists and physical therapist assistants, the book with its illustrations and text helps anyone gain a thorough understanding of the human musculoskeletal system and movement. I highly recommend this book for anyone studying anatomy and believe that MTs, PTAs, and teachers of body movements should have this book in their possession. I also highly recommend this book for the layperson who wants to gain an understanding of the muscle, skeletal system and how our bodies move. This book will not disappoint!

Out of the scores of books in my office, Basic Clinical Massage Therapy is by far the most referenced book in my library. The musculoskeletal system is overlaid on human models allowing you to learn the precise location, origin, and insertions of each muscle. The models are pictured in various poses throughout the book which also helps you visualize muscles in motion and their actions relationship with the skeletal structure and other muscles. Though it is written for massage therapists, it is an excellent book for anyone who wants to learn about the muscular system. MT’s will benefit from the recommended treatments for each muscle.

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