Scapula and Upper Extremity Flashcards
Deltoid origin (proximal)
Lateral 1/3 of clavicle, lateral acromion, inferior edge spine of scapula
Deltoid insertion (distal)
Deltoid tuberosity of humerus
Deltoid innervation
Axillary nerve (originates from brachial plexus - C5/C6)
Deltoid action
Clavicular: flexes and medially rotates arm
Acromial: abducts beyond 15 degrees
Spinal: extends and laterally rotates arm
Deltoid blood supply
Posterior circumflex humeral artery, deltoid branch of thoraco-acromial artery
Supraspinatus origin (proximal)
Supraspinatus fossa of scapula
Supraspinatus insertion (distal)
Inferior facet of greater tubercle of humerus
Supraspinatus innervation
Suprascapular nerve (brachial plexus - C5/C6)
Supraspinatus action
Initiates arm abduction up to 15 degrees (rotator cuff)
Supraspinatus blood supply
Suprascapular artery
Infraspinatus origin (proximal)
Infraspinatus fossa of scapula
Infraspinatus insertion (distal)
Middle facet of greater tubercle of humerus
Infraspinatus innervation
Suprascapular nerve
Infraspinatus blood supply
Suprascapular artery
Infraspinatus action
Lateral rotation of arm (rotator cuff)
Teres major origin
Posterior surface of inferior angle of scapula
Teres major insertion
Medial lip of intertubercular sulcus of humerus
Teres major innervation
Lower subscapular nerve (brachial plexus C5/C6)
Teres major action
Adducts and medially rotates arm
Teres major blood supply
Circumflex scapular artery
Teres minor origin
Upper 2/3 of posterior surface of lateral border of scapula
Teres minor insertion
Inferior facet of greater tubercle of humerus
Teres minor innervation
Axillary nerve (brachial plexus C5/C6)
Teres minor action
Laterally rotates arm (rotator cuff)
Teres minor blood supply
Circumflex scapular artery
Subscapularis origin
Subscapular fossa (anterior portion of scapula)
Subscapularis insertion
Lesser tubercle of humerus
Subscapularis innervation
Upper and lower subscapular nerves (brachial plexus C5/C6)
Subscapularis action
Medially rotates and adducts arm at shoulder, holds humeral head in glenoid cavity
Subscapularis blood supply
Subscapular artery, lateral thoracic artery