Pectoralis Major - Muscle Physiology & Functional Anatomy

 

Pectoralis Major Muscle

Anatomy

 

Origin:

  • Sternal head

    • Anterior surface of the sternum, the superior six costal cartilages (2nd to 6th ribs), and the aponeurosis of the external oblique muscle

  • Clavicular head

    • Anterior surface of the medial half of the clavicle.

Insertion:

  • Sternal head

    • Intertubercular groove of the proximal, anterior humerus 

  • Clavicular head

    • Intertubercular groove of the proximal, anterior humerus 

 

Major Arteries:

  • Pectoral branch of the thoracoacromial (trunk) artery

 

Neural Innervation:

  • Sternal head

    • Lateral & medial pectoral nerves C7-C8 & T1

  • Clavicular head

    • Lateral & medial pectoral nerves C5-C6

 

Trigger Points:

Trigger Points of the Pectoralis Major Pec Major Trigger Point

Trigger Points in Pec Major for Women

 

Physiology

 

Concentric Functions:

  • Sternal head

    • Transverse flexion, adduction, internal rotation, adduction & extension of the shoulder

  • Clavicular head

    • Transverse flexion, adduction, internal rotation, adduction, flexion & abduction of the shoulder 

 

Eccentric Functions:

  •  Decelerates shoulder extension, horizontal abduction and external rotation

 

Isometric Function:

  • Assists in dynamically stabilizing the shoulder complex during overhead movements

 

Related Muscles

Antagonists:

Exercises:

 

 

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More Images of the Pectoralis Major Muscle

 

Pectoralis Major

Pec Major

 


More Information about the Pectoralis Major Muscle