Scapulohumeral (Intrinsic Shoulder) Muscles Flashcards
Deltoid Insertion
Deltoid tuberosity of humerus
Deltoid Origin
Lateral third of clavicle; acromion and spine of scapula
Deltoid Innervation
Axillary nerve (C5, C6)
Deltoid Actions
Clavicular (anterior) part flexes and medially rotates should joint; acromial (middle) part abducts shoulder joint; spinal (posterior) part extends and laterally rotates shoulder joint
Supraspinatus Origin
Supraspinous fossa of scapula
Supraspinatus insertion
Super facet of greater tubercle of humerus
Supraspinatus innervation
Suprascapular nerve (C4 C5, C6)
Supraspinatus Actions
initiates and assists deltoid in abduction of shoulder joint and acts with other rotator cuff muscles
Infraspinatus Origin
Infraspinous fossa of scapula
Infraspinatus Insertion
Middle facet of greater tubercle of humerus
Infraspinatus Innervation
suprascapular nerve (C5, C6)
Infraspinatus Action
Laterally rotate shoulder joint; help hold humeral head in glenoid cavity of scapula
Teres Minor origin
middle part of lateral border of scapula
Teres Minor insertion
Inferior facet of greater tubercle of humerus
teres minor innervation
axillary nerve (C5, C6)
teres minor action
Laterally rotate shoulder joint; help hold humeral head in glenoid cavity of scapula
Teres major origin
inferior part of lateral border of scapula and posterior surface of inferior angle of scapula
Teres major insertion
medial lip of intertubercular sulcus of humerus
Teres major innervation
Lower subscapular nerve (C5,C6)
Subscapularis Origin
Subscapular fossa
Subscapularis Insertion
Lesser tubercle of humerus
Subscapularis Innervation
Upper and lower subscapular nerves (C5, C6, C7)
Subscapularis Action
Medially rotates and adducts shoulder joint; helps hold humeral head in glenoid cavity
