Deltoid-Action All fibers:   *ABDUCT the shoulder (glenohumeral joint) Anterior fibers:   *flex the shoulder (g/h joint)   *medially rotate shoulder (g/h joint)   *horizontally adduct the shoulder (g/h joint) Posterior fibers:   *Extend the shoulder (g/h joint)   *Laterally rotate the shoulder (g/h joint)   *Horizontally ABduct the shoulder (g/h joint) Deltoid-Origin Lateral one-third of clavicle, acromion and spine of scapula Deltoid- Insertion Deltoid Tuberosity Deltoid-Innervation Axillary C5, 6 Trapezius-Action Upper fibers:   *Bilaterally      *Extend the head and neck   *Unilaterally      *Laterally flex the head and neck to the same side      *Rotate the head and neck to the opposite side      *Elevate the scapula (scapulothoracic joint)      *Upwardly rotate the scapula (s/t joint) Middle fibers:   *Adduct the scapula (s/t joint)   *Stabilize the scapula (s/t joint) Lower fibers:   *Depress the scapula (s/t joint)   *Upwardly rotate the scapula (s/t joint) Trapezius-Origin External Occipital protuberance, medial portion of superior nuchal line of the occiput, ligamentum nuchae and spinous process of C-7 through T-12 Trapezius-Insertion Lateral one-third of clavicle, acromion and spine of the scapula Trapezius-Innervation Spinal portion of cranial nerve XI (accessory) and ventral ramus C2, 3, 4 Latissimus Dorsi-Action Extend the shoulder (g/h joint) Adduct the shoulder (g/h joint) Medially rotate the shoulder (g/h joint) Latissimus Dorsi-Origin Inferior angle of scapula, spinous process of last 6 thoracic vertebrae, last 3 or 4 ribs, throacolumbar aponeurosis and posterior iliac crest Latissimus Dorsi-Insertion Intertubercular groove of the humerus Latissimus Dorsi-Innervation Thoracodorsal C6, 7, 8 Teres Major-Action *Note: Teres major and latissimus dorsi share the same actions Extend the shoulder (g/h joint) Adduct the shoulder (g/h joint) Medially rotate the shoulder (g/h joint) *note: could be more than one option * Teres Major-Origin Inferior Angle and lower one-third of lateral border of the scapula Teres Major-Insertion Crest of the lesser tubercle of the humerus Teres Major-Innervation Lower subscapular C5, 6, 7 Rotator Cuff Muscles SITS   Supraspinatus   Infraspinatus   Teres minor   Subscapularis Supraspinatus-Action Abduct the shoulder (g/h joint) Stabilize the head of the humerus in glenoid cavity Supraspinatus-Origin Supraspinous fossa of the scapula Supraspinatus-Insertion *note: same as infraspinatus and teres minor Greater tubercle of the humerus Supraspinatus-Innervation *note: same as infraspinatus Suprascapular C4, 5, 6 Infraspinatus-Action *note: same as teres minor Laterally rotate the shoulder (g/h joint) Adduct the shoulder (g/h joint) Stabilize the head of humerus in glenoid cavity Infraspinatus-Origin Infraspinous fossa of the scapula Infraspinatus-Insertion *note: same as supraspinatus, and teres minor Greater Tubercle of the humerus Infraspinatus-Innervation *note: same as supraspinatus Suprascapular C4, 5, 6 Teres Minor-Action *note: same as infraspinatus Laterally rotate the shoulder (g/h joint) Adduct the shoulder (g/h joint) Stabilize the head of humerus in glenoid cavity Teres Minor-Origin Upper two-thirds of lateral border of the scapula Teres Minor-Insertion *note: same as infra and supraspinatus Greater tubercle of the humerus Subscapularis-Action Medially rotate the shoulder (glenohumeral joint) Stabilize the head of humerus in glenoid cavity Subscapularis-Origin Subscapular fossa of the scapula Subscapularis-Insertion Lesser tubercle of the humerus Subscapularis-Innervation Upper and lower subscapular C5, 6, 7 Rhomboid Major and Minor-Action Adduct the scapula (scapulothoracic joint) Elevate the scapula (s/t joint) Downwardly rotate teh scapula (s/t joint) Rhomboid Major and Minor-Origin Major:    Spinous processes of T-2 to T-5 Minor:    Spinous processes of C-7 and T-1 Rhomboid Major and Minor-Insertion Major:    Medial border of the scapula between the spine of the scapula and the inferior angle Minor:    Upper portion of medial border of the scapula, across from spine and scapula Rhomboid Major and Minor-Innervation Dorsal scapular C4, 5 Levator Scapula-Action Unilaterally:   *Elevate the scapula (scapulothoracic joint)   *Downwardly rotate the scapula (S/t joint)   *Laterally flex the head and neck   *Rotate the head and neck to the same side Bilaterally:   *Extend the head and neck Levator Scapula-Origin Transverse processes of the first through fourth cervical vertebrae Levator Scapula-Insertion Medial border of scapula, between superior angle and superior portion of spine of scapula Levator Scapula-Innervation Cervical 3, 4, and Dorsal Scapular C4, 5 Serratus Anterior-Action With the origin fixed:   *Abduct the scapula (scapulorthoracic joint)   *Upwardly rotate the scapula (s/t joint)   *Depress the scapula (s/t joint)   *Hold the medial border of the scapula against the rib cage With the scapula fixed:   *may act to elevate the thorax during forced inhalation Serratus Anterior-Origin External surfaces of upper eight or nine ribs Serratus Anterior-Insertion Anterior surface of medial border of the scapula Serratus Anterior-Innervation Long Thoracic C5, 6, 7, 8 Pectoralis Major-Action All fibers:   *Adduct the shoulder (g/h joint)   *Medially rotate the shoulder (g/h joint)   *Assist to elevate the thorax during forced inhalation (with the arm fixed) Upper fibers:   *Flex the shoulder (g/h joint)   *Horizontally adduct the shoulder (g/h joint) Lower fibers:   *Extend the shoulder (g/h joint) Pectoralis Major-Origin Medial half of clavicle, sternum and cartilage of the 1st-6th ribs Pectoralis Major-Insertion Crest of greater tubercle of humerus Pectoralis Major-Innervation Upper fibers:   *Lateral Pectoral C5, 6, 7 Lower fibers:   *Lateral and medial pectoral C6, 7, 8, T1 Pectoralis Minor-Action Depress the scapula (scapulothoracic joint) Abduct the scapula (s/t joint) Downwardly rotate the scapula (s/t joint) With the scapula fixed:   *Assist to elevate the thorax during forced inhalation Pectoralis Minor-Origin 3rd, 4th, and 5th ribs Pectoralis Minor-Insertion Medial surface of coracoid process of the scapula Pectoralis Minor-Innervation Medial pectoral, with fibers from a communicating branch of the lateral pectoral C6, 7, 8, T1 Subclavius-Action Depress the clavicle and draw it anteriorly Elevate the first rib (to assist during inhalation) Stabilize the sternoclavicular joint Subclavius-Origin First rib and cartilage Subclavius-Insertion Inferior surface of middle one-third of clavical Subclavius-Innervation Subclavian C5, 6 Biceps Brachii-Action Flex the elbow (humeroulnar joint) Supinate the forearm (radioulnar joints) Flex the shoulder (glenohumeral joint) Biceps Brachii-Origin Short head:   *coracoid process of scapula Long head:   *supraglenoid tubercle of scapula Biceps Brachii-Insertion Tuberosity of the radius and aponeurosis of the biceps brachii Biceps Brachii-Innervation Musculocutaneous C5, 6 Triceps Brachii-Action All heads:   *Extend the elbow (humeroulnar joint) Long head:   *Extend the shoulder (g/h joint)   *Adduct the shoulder (g/h joint) Triceps Brachii-Origin Long head:   *Infraglenoid tubercle of the scapula Lateral head:   *Posterior surface of proximal half of the the humerus Medial Head:   *Posterior surface of distal half of the humerus Triceps Brachii-Insertion Olecranon process of the ulna Triceps Brachii-Innervation Radial C6, 7, 8, T1 Coracobrachialis-Action Flex the shoulder (g/h joint) Adduct the shoulder (g/h joint) Coracobrachialis-Origin Coracoid process of the scapula Coracobrachialis-Insertion Medial surface of mid-humeral shaft Coracobrachialis-Innervation Musculocutaneous C6, 7