Upper Limb Unit Muscles

Front 1

Coracobrachialis

Back 1

*Muscles of the Anterior Arm*

Origin:

Coracoid process of Scapula

Insertion:

Middle of medial surface of shaft of humerus

Action:

Flexes arm (Shoulder)

Adducts arm (Shoulder

Innervation:

Musculocutaneous nerve

Front 2

Biceps Brachii - Short Head

Back 2

*Muscles of the Anterior Arm*

Origin:

Coracoid process of Scapula

Insertion:

Radial tuberosity (common tendon w/ long head)

Deep fascia of forearm via bicipital aponeurosis

Action:

Flex forearm (Elbow) when forearm supinated

Supinates forearm (Radioulnar)

Weak flex of arm (Shoulder)

Innervation:

Musculocutaneous nerve

Front 3

Biceps Brachii - Long Head

Back 3

*Muscles of the Anterior Arm*

Origin:

Supraglenoid tubercle of Scapula

Insertion:

Radial tuberosity (common tendon w/ short head)

Deep fascia of forearm via bicipital aponeurosis

Action:

Flex forearm (Elbow) when forearm supinated

Supinates forearm (Radioulnar)

Weak flex of arm (Shoulder)

Innervation:

Musculocutaneous nerve

(Lateral Long Tendon)

Front 4

Brachialis

Back 4

*Muscles of the Anterior Arm*

Origin:

Distal half of anterior surface of Humerus

Insertion:

Coronoid process of ulna

Ulnar tuberosity

Action:

Flex forearm (Elbow)

Innervation:

Musculocutaneous nerve

Front 5

Triceps Brachii

(Long, Lateral, Medial)

Back 5

*Muscles of the Posterior Arm*

Origin:

Long - Infraglenoid tubercle of scapula

Lateral - Posterior surface of humerus superior to radial (spiral) groove

Medial - Posterior surface of humerus inferior to radial (spiral) groove

Insertion:

Olecranon of ulna (common tendon w/ tri)

Action:

Extend arm (Elbow)

Innervation:

Radial nerve

Front 6

Brachioradialis

Back 6

*Muscles of the Posterior Forearm - Superficial*

Origin:

Ridge superior to the lateral epicondyle of Humerus (i.e. lateral supracondylar ridge)

Insertion:

Lateral surface of distal end of radius just proximal to styloid process

Action:

Flex forearm (Elbow)

Innervation:

Radial nerve

Front 7

Extensor Carpi Radialis Longus

Back 7

*Muscles of the Posterior Forearm - Superficial*

Origin:

Ridge superior to the later epicondyle of Humerus (i.e. lateral supracondylar ridge)

Action:

Extend Hand (Wrist)

Abducts Hand (Wrist)

Innervation:

Radial nerve

Front 8

Extensor Carpi Radialis Brevis

Back 8

*Muscles of the Posterior Forearm - Superficial*

Origin:

Lateral epicondyle of Humerus

Action:

Extends Hand (Wrist)

Abducts Hand (Wrist)

Innervation:

Radial nerve

Front 9

Extensor Digitorum

Back 9

*Muscles of the Posterior Forearm - Superficial*

Origin:

Lateral epicondyle of Humerus

Action:

Extends digits 2-5

Extends hand (Wrist)

Innervation:

Radial nerve

Front 10

Extensor Digiti Minimi

Back 10

*Muscles of the Poster Forearm - Superficial*

Origin:

Lateral epicondyle of Humerus

Action:

Extends digit 5

Extends hand (Wrist)

Innervation:

Radial nerve

Front 11

Extensor Carpi Ulnaris

Back 11

*Muscles of the Posterior Forearm - Superficial*

Origin:

Lateral epicondyle of Humerus

Action:

Extend hand (Wrist)

Adducts hand (Wrist)

Front 12

Anconeus

Back 12

*Muscles of the Posterior Forearm - Superficial*

Origin:

Lateral epicondyle of Humerus

Action:

Extends forearm (Elbow)

Innervation:

Radial nerve

Front 13

Supinator

Back 13

*Muscles of the Posterior Forearm - Deep*

Origin:

Lateral epicondyle of Humerus

Crest of Ulna

Insertion:

All surfaces of proximal third of radius

Action:

Supinates forearm (Radioulnar)

Innervation:

Radial nerve

Front 14

Abductor Pollicis Longus

Back 14

*Muscles of the Posterior Forearm - Deep*

Origin:

Ulna

Radius

Interosseous Membrane

Action:

Abduct digit 1

Extend digit 1

Innervation:

Radial nerve

Front 15

Extensor Pollicis Brevis

Back 15

*Muscles of the Posterior Forearm - Deep*

Origin:

Radius

Interosseous Membrane

Action:

Extends digit 1

Innervation:
Radial nerve

Front 16

Extensor Pollicis Longus

Back 16

*Muscles of the Posterior Forearm - Deep*

Origin:

Ulna

Interosseous Membrane

Action:

Extends digit 1

Innervation:

Radial nerve

Front 17

Extensor Indicis

Back 17

*Muscles of the Posterior Forearm - Deep*

Origin:

Ulna

Interosseous Membrane

Action:

Extends digit 2

Innervation:

Radial nerve