Scapulohumeral (Intrinsic Shoulder) Muscles Flashcards
Deltoid Origin-3
- Lateral 1/3 of clavicle
- Acromion
- Spine of scapula
Deltoid Insertion
Deltoid tuberosity of humerus
Deltoid Innervation
Axillary nerve (C5, C6)
Deltoid Action-3
Anterior-Flexes and medially rotates arm
Middle-Abducts arm
Posterior-Extends and laterally rotates arm
Supraspinatous Origin
Supraspinous fossa of scapula
Supraspinatous Insertion
Superior facet of greater tubercle of humerus
Supraspinatous Innervation
Suprascapular nerve (C4, C5, C6)
Supraspinatous Action
Initiates and assists deltoid in abduction of arm
Infraspinatous Origin
Infraspinous fossa of scapula
Infraspinatous Insertion
Middle facet of greater tubercle of humerus
Infraspinatous Innervation
Suprascapular nerve (C5, C6)
Infraspinatous Action
Laterally rotate arm
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 arm
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 arm
Teres Major Origin
Posterior surface of inferior angle of scapula
Rotator cuff muscles collective action
Their primary function during all movements of the shoulder is to hold the humeral head in the glenoid cavity
Teres Major Insertion
Medial lip of interubercular groove of humerus
Teres Major Innervation
Lower subscapular nerve (C5, C6)
Teres Major Action
Adducts and medially rotates arm
