| Shoulder and arm | ||||
| Muscle | Origin | Insertion | Action | Notes |
| Deltoid | Lateral one-third of clavicle, acromion and spine of scapula | Deltoid tuberosity of humerus | Abduct the shoulder jointPosterior fibers extend and laterally rotate shoulder. Anterior fibers flex and medially rotate the shoulder. | Origin is identical to the insertion of the trapezius. |
| Supraspinatus”Rotator cuff” | Supraspinatus fossa of scapula | Greater tubercle of humerus – superior facet | Abducts the humerus; stabilizes head of humerus in glenoid cavity.Medially rotates humerus, draws it forward and down when arm is raised. | Deep to trapezius-runs underneath the acromion.(only rotator cuff muscle that doesn’t rotate) |
| Infraspinatus”Rotator cuff” | Infraspinous fossa of scapula | Greater tubercle of humerus – middle facet | Laterally rotate, adducts, extends the shoulder. Stabilizes head of humerus in glenoid cavity | Attaches just posterior to the supraspinatus on the greater tubercle.Works with teres minor. |
| Teres Minor” Rotator cuff” | Superior half of lateral border of scapula | Greater tubercle of humerus, lowest facet | Laterally rotates, adducts, extends the shoulder, stabilizes head of humerus in glenoid cavity | |
| Subscapularis”Rotator Cuff” | Subscapular fossa of the scapula | Lesser tubercle of the humerus | Medially rotates shoulder joint, stabilizes head of humerus in glenoid cavity. | Most often the culprit in “frozen shoulder” |
| Teres Major | Inferior angle of scapula | Medial lip of bicipital grove of humerus | Adducts and medially rotates humerus and draws it back. | |
| Serratus Anterior | Outer surface of ribs 1-8 | Anterior medial border of scapula | Abducts and upwardly rotates scapula, holds scapula against thoracic wall | Lower fibers interdigitate with the external obliques. Weakness causes winged scapula. Tightness may cause “a stitch in the side” |
| Coracobracialis | Corocoid process of scapula | Middle of medial shaft of humerus | Flexes and adducts the humerus | |
| Biceps Brachii | Short head- Coracoid process of scapulaLong head- Supraglenoid tubercle of scapula | Tuberosity of the radius and aponeurosis of biceps brachii | Flexes elbow, supinates forearm, flexes shoulder joint | |
| Triceps Brachii | Long head- Infraglenoid tubercle of scapulaLateral head- Posterior surface of proximal half of humerus
Medial head- Posterior surface of distal half of humerus |
All heads- olecranon process of ulna | Long head- Extends and adducts the shoulderAll heads- Extend the forearm (elbow) | |
| Subclavius | First rib and cartilage | Inferior, lateral aspect of clavicle | Elevates first rib, stabilizes sternoclavicular joint, draws clavicle down | Underneath the clavicle. |
| Brachialis | Distal half of the anterior surface of humerus | Tuberosity and coronoid process of ulna | Flexes the elbow | |
| Bracioradialis | Lateral supracondylar ridge of humerus | Styloid process of radius | Flexes forearm (handshake position) | |
| Pronator teres | Medial epicondyle of humerus, coronoid process of ulna | Middle of lateral surface of radius | Pronates the forearmAssists in flexion of the elbow | Resisted pronation |
| Forearm and hand | ||||
| Extensor digitorum | Common extensor tendon from lateral epicondyle of humerus | Dorsal surface of middle and distal phalanges 2-5 ( four fingers) | Extends four fingers, assists in extension of the wrist | |
| Pronator quadratus | ||||
| Palmaris longus | Medial epicondyle of humerus | Palmar aponeurosis | Flexion of hand and wrist | Flex wrist against resistance to find tendon.May be absent in one or both sides in some people. |
| Flexor digitorum superficialis | Medial epicondyle of humerus, coronoid process of ulna, proximal radius | Four tendons into the middle phalanges of fingers 2-5, palmar surface | Flexes the middle and proximal phalanges of fingers 2-5, flexion of the wrist and forearm. | Median nerve and ulnar artery are under origin |
| Flexor carpi radialis | Medial epicondyle of humerus | Base of 2nd to base of 3rd metacarpal bone | Flexes and abducts the wrist, pronation of the forearm and flexion of the elbow | |
| Flexor carpi ulnaris | Medial epicondyle of humerus, medial olecranon and proximal posterior ulna | Pisiform bone | Flexes and adducts the wrist and flexes the elbow | |
| Extensor carpi radialis longus | Lateral supracondylar ridge of humerus | Base of 2nd metacarpal bone dorsal side | Extends and abducts the wrist, flexes the elbow | |
| Extensor carpi radialis brevis | Lateral epicondyle of humerus | Dorsal surface of base of 3rd metacarpal bone | Extends and assists in abduction of the wrist | |
| Extensor carpi ulnaris | Lateral epicondyle of humerus, posterior border of ulna | Base of 5th metacarpal bone, ulnar side | Extends and adducts the wrist | Tendon runs through a groove between the head of the ulna and the styloid process of ulna |
| Flexor digitorum profundus | Anterior and medial surfaces of proximal ¾ of ulna | Four tendons into bases of distal phalanges on anterior surface | Flexes distal interphalangeal joints of four fingers, flexes proximal interphalageal and metacarpopphalangeal joints | |
| Flexor pollicus longus | Anterior surface of radius, deep to flexors | Distal phalange of thumb | Flexes thumb | |
| Supinator | Lateral epicondyle of humerus, posterior ulna | Proximal anterior shaft of humerus | Supinates forearm | |
| Extensor pollicus longus and brevis | Posterior surface of radius and ulna, deep to extensors | Brevis –proximal phalange of thumbLongus- distal phalange of thumb | Extends the thumb | |
| Opponens pollicis | Palmar retinaculum, trapezium | 1st metacarpal anterior surface | Opposition of thumb to each digit.Rotates 1st metacarpal so the thumbnail faces the ceiling when the hand is resting palm up. |