muscle chart 11-20

origin or teres major

inferior angle and lateral border of the scapula

insertion of teres major

medial lip of intertubercular sulcus of humerus

action of teres major

adducts and medially rotates shoulder joint

innervation of teres major

lower subscapular nerve (C5, C6)

origin of subscapularis

subscapular fossa of the scapula

insertion of subscapularis

lesser tubercle of the humerus

action of subscapularis

medially rotates the shoulder; stabilizes the head of the humerus in glenoid cavity

innervation of subscapularis

upper and lower subscapular nerve (C5, C6, C7)

origin of supraspinatus

supraspinous fossa of the scapula

insertion of supraspinatus

greater tubercle of the humerus

action of supraspinatus

initiates and assists deltoid in abduction of the shoulder joint; stabilizes the head of humerus in glenoid cavity

innervation of supraspinatus

suprascapular nerve (C4, C5, C6)

origin of infraspinatus

infraspinous fossa of the scapula

insertion of infraspinatus

greater tubercle of the humerus

action of infraspinatus

laterally rotates the shoulder joint; stabilizes the head of humerus in glenoid cavity

innervation of infraspinatus

suprascapular nerve (C5, C6)

origin of teres minor

lateral border of the scapula

insertion of teres minor

greater tubercle of the humerus

action of teres minor

laterally rotates the shoulder joint; stabilizes the head of the humerus in glenoid cavity

innervation of teres minor

axillary nerve ((C5, C6)

origin of biceps brachii

short head: coracoid process of scapula

long head: supraglenoid tubercle of scapula

insertion of biceps brachii

tuberosity of the radius and bicipital aponeurosis

action of biceps brachii

supinates forearm; flexes elbow joint; flexes shoulder joint

innervation of biceps brachii

musculocutaneous nerve (C5, C6)

origin of brachialis

anterior surface of humerus

insertion of brachialis

tuberosity and coracoid process of ulna

action of brachialis

flexes the elbow joint

innervation of brachialis

musculocutaneous nerve (C5, C6) and small contribution from the radial nerve

origin of coracobrachialis

coracoid process of the scapula

insertion of coracobrachialis

medial surface of mid-humeral shaft

action of coracobrachialis

flex the shoulder; adduct the shoulder

innervation of coracobrachialis

musculocutaneous nerve (C5, C6, C7)

origin of triceps brachii

long head: infraglenoid tubercle of the scapula

lateral head: posterior surface of the proximal humerus

medial head: posterior surface of the distal humerus

insertion of triceps brachii

olecranon process of the ulna

action of triceps brachii

all heads: extends elbow

long head: extends the shoulder

innervation of triceps brachii

radial nerve (C6, C7, C8)

origin of anconeus

lateral epicondyle of the humerus

insertion of anconeus

olecranon process

action of anconeus

extends the elbow

innervation of anconeus

radial nerve (C7, C8, T1)