Scapular Region

• Deltoid
  • Bony Attachments:
    • 1: Lateral clavicle, acromion, spine of scapula.
    • 2: Deltoid tuberosity of the humerus.
  • Innervation: Axillary nerve (C5,6) from the posterior cord of the brachial plexus.
  • Arterial Supply: Posterior circumflex humeral a.
  • Action: Abducts arm; anterior fibers flex & medially rotate the arm; posterior fibers extend & laterally rotate the arm.
• Supraspinatus - Rotator Cuff Muscle
  • Bony Attachments:
    • 1: Supraspinatous fossa.
    • 2: Greater tubercle of the humerus.
  • Innervation: Suprascapular nerve (C5,6) from the superior trunk of the brachial plexus.
  • Arterial Supply: Suprascapular a.
  • Action: Abducts the arm (initiates abduction).
• Infraspinatus - Rotator Cuff Muscle
  • Bony Attachments:
    • 1: Infraspinatous fossa
    • 2: Greater tubercle of the humerus.
  • Innervation: Suprascapular nerve.
  • Arterial Supply: Suprascapular a.
  • Action: Laterally rotates the arm.
• Teres minor - Rotator Cuff Muscle
  • Bony Attachments:
    • 1: Upper 2/3 of the lateral border of the scapula.
    • 2: Greater tubercle of the humerus.
  • Innervation: Axillary nerve (C5,6) from the posterior cord of brachial plexus.
  • Arterial Supply: Circumflex scapular a.
  • Action: Laterally rotates the arm.
• Teres major
  • Bony Attachments:
    • 1: Dorsal surface of the inferior angle of the scapula.
    • 2: Lesser tubercle of the humerus.
  • Innervation: Lower subscapular nerve (C5,6) from the posterior cord of the brachial plexus.
  • Arterial Supply: Circumflex scapular a.
  • Action: Adducts the arm, medially rotates the arm, assists in arm extension.
• Subscapularis - Rotator Cuff Muscle
  • Bony Attachments:
    • 1: Medial two-thirds of the costal surface of the scapula (subscapular fossa).
    • 2: Lesser tubercle of the humerus.
  • Innervation: Upper and lower subscapular nerves (C5,6).
  • Arterial Supply: Subscapular a.
  • Action: Medially rotates the arm; assists extension of the arm.