Shoulder and Brachial Muscle OIA

Trapezius Origin

superior nuchal line; external occipital protuberance; spinous processes of C7-T12

Trapezius Insertion

lateral clavicle; acromoin process; spine of scapula

Trapezius Action

elevates scapula; retracts scapula; depresses scapula; rotates scapula

Latissimus Dorsi Origin

spinous process of T7-L5; iliac crest; ribs 9-12

Latissimus Dorsi Insertion

intertubercular sulcus

Latissimus Dorsi Action

extends shoulder; adducts shoulder; internally rotates shoulder

Rhomboid Major Origin

spinous processes of T2-T5

Rhomboid Major Insertion

medial border of scapula inferior to spine of scapula

Rhomboid Major Action

fixes scapula to thoracic wall; retracts scapula; downwardly rotates scapula

Rhomboid Minor Origin

spinous process of C7-T1

Rhomboid Minor Insertion

base of scapular spine

Rhomboid Minor Action

fixes scapula to thoracic wall; retracts scapula; downwardly rotates scapula

Levator Scapulae Origin

posterior tubercles of transverse processes of C1-C4

Levator Scapulae Insertion

medial border of scapula superior to spine of scapula

Levator Scapulae Action

elevates scapula; downwardly rotates scapula

Supraspinatus Origin

supraspinous fossa

Supraspinatus Insertion

superior facet of greater tubercle

Supraspinatus Action

abducts shoulder

Infraspinatus Origin

infraspinous fossa

Infraspinatus Insertion

middle facet of greater tubercle

Infraspinatus Action

externally rotates shoulder

Teres Major Origin

posterior surface of inferior angle of scapula

Teres Major Insertion

medial border of intertubercular sulcus

Teres Major Action

extends shoulder; adducts shoulder; internally rotates shoulder

Teres Minor Origin

superior posterior surface of lateral border of scapula

Teres Minor Insertion

inferior facet of greater tubercle

Teres Minor Action

externally rotates shoulder

Deltoid Origin

lateral anterior clavicle; acromion; spine of scapula

Deltoid Insertion

deltoid tuberosity

Deltoid Action

flexes shoulder; internally rotates shoulder; abducts shoulder; extends shoulder; externally rotates shoulder

Serratus Anterior Origin

lateral surfaces of ribs 1-9

Serratus Anterior Insertion

costal surface of medial border of scapula

Serratus Anterior Action

fixes scapula to thoracic wall; protracts scapula; upwardly rotates scapula

Pectoralis Major Origin

medial clavicle; sternum; cartilages of true ribs

Pectoralis Minor Insertion

lateral lip of intertubercular sulcus of humerus

Pectoralis Major Action

flexes shoulder; adducts shoulder; internally rotates shoulder

Pectoralis Minor Origin

external surface of ribs 3-5

Pectoralis Minor Insertion

coracoid process of scapula

Pectoralis Minor Action

protracts scapula; downwardly rotates scapula

Subscapularis Origin

subscapular fossa

Subscapularis Insertion

lesser tubercle

Subscapularis Action

internally rotates shoulder; adducts shoulder; stabilizes shoulder during abduction

Coracobrachialis Origin

coracoid process of scapula

Coracobrachialis Insertion

middle medial surface of humerus

Coracobrachialis Action

flexes shoulder; adducts shoulder

Biceps Brachii Origin

long head: supraglenoid tubercle

short head: coracoid process of scapula

Biceps Brachii Insertion

radial tuberosity

Biceps Brachii Action

flexes shoulder; flexes elbow; supinates elbow

Brachialis Origin

distal anterior surface of humerus

Brachialis Insertion

coronoid process of ulna; tuberosity of ulna

Brachialis Action

flexes elbow

Triceps Brachii Origin

long head: infraglenoid tubercle

lateral head: proximal posterior humerus

medial head: distal and posterior humerus

Triceps Brachii Insertion

posterior olecranon process

Triceps Brachii Action

extends elbow; stabilizes shoulder during abduction; extends shoulder; adducts shoulder