Pectoralis Minor Muscle Anatomy: Origin, Insertion, Actions

Pectoralis Minor Muscle Anatomy: Origin, Insertion, Action and Innervation

Pectoralis Minor
Origin: Anterior surfaces of the third to fifth ribs. (variable)
Insertion: Via a tendon to the medial aspect of the coracoid process of the scapula. Part or all of the tendon may transverse this process and continue into the coracoacromial ligament.
Action: Scapula protraction, rotation of the scapula downwards
Innervation: Medial pectoral nerve (C7, T1)
Blood Supply: Branches from the thoraco-acromial artery

Synergist: Pectoralis major

Primary Actions of the Pectorails Minor:

1. Protraction of the scapula

  • Agonists: Serratus Anterior
  • Antagonists: Trapezius (middle fibers), Rhomboid Major, Rhomboid Minor

2. Depression of the scapula

  • Agonists: Serratus Anterior (lower fibers), Trapezius (lower fibers)
  • Antagonists: Levator Scapulae, Trapezius (upper fibers)

Secondary Actions of the Pectoralis Minor:

1. Assists with downward rotation of the scapula

  • Agonists: Levator Scapulae, Serratus Anterior (upper fibers), Rhomboid Major, Rhomboid Minor, Trapezius (middle fibers)
  • Antagonists: Trapezius (upper and lower fibers), Serratus Anterior (lower fibers),

Stabilizer: Trapezius (middle fibers)

For more information see: Pectoralis Minor Pain and Symptoms


Recommended Anatomy Books

coloring_book 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 how the act of coloring will help with recall. But this is not just a beginners 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.


Trail Guide To The Body   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 lay person who wants to gain understanding of the muscle, skeletal system and how our bodies move. This book will not disappoint!


References:

The Trigger Point Therapy Workbook – Claire Davies, Amber Davies, and David G. Simons

Basic Clinical Massage Therapy: Integrating Anatomy and Treatment – James H. Clay and David M. Pounds

Trigger Point Therapy for Myofascial Pain – Donna Finando and Steven Finando

Massage Therapy Principles and Practice – Susan Salvo

Theory & Practice of Therapeutic Massage – Mark Beck

 

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