Upper Extremity Week 2 Structure Information: Muscles

Question 1

Anconeus

Answer 1

(C7-8)

attachments- from lateral epicondyle of humerus to lateral surface of the olecranon process

actions- extension of the elbow

innervation- radial nerve

Question 2

Biceps brachii

Answer 2

(C5-6)

attachments- from coracoid process (short head) & supraglenoid tubercle (long head) of the scapula to the radial tuberosity & the deep antebrachial fascia (through the bicipital aponeurosis)

actions- flexion of the shoulder & elbow, & supination of the forearm

innervation- musculocutaneous nerve

Question 3

Brachialis

Answer 3

(C5-6)

attachments- from the distal anterior shaft of the humerus & lateral & medial intermuscular septa to the coronoid process & ulnar tuberosity

actions- flexion of the elbow

innervation- musculocutaneous & small branch from radial nerve

Question 4

Coracobrachialis

Answer 4

(C6-7)

attachments- from the coracoid process to the proximal medial shaft of the humerus

actions- flexion & adduction of the shoulder

innervation- musculocutaneous nerve

Question 5

Triceps brachii

Answer 5

(C6-T1)

attachments- from the infraglenoid tubercle of the scapula (long head), & proximal posterolateral (lateral head) & distal posteromedial (medial) shaft of the humerus to the olecranon process of the ulna

actions- extension of the shoulder (long head) & extension of the elbow (long, lateral & medial heads)

innervation- radial nerve

Question 6

Abductor pollicis longus

Answer 6

(C6-8)

attachments- from proximal posterior radius, ulna & interosseous membrane to the base of the 1st metacarpal & trapezium

actions- abducts & extends thumb at carpometacarpal joint & abducts hand at wrist (radial deviation)

innervation- radial nerve

Question 7

Brachioradialis

Answer 7

(C5-6)

attachments- from the lateral supracondylar ridge of the humerus to the distal radius lateral to the styloid process

actions- flexes the elbow

innervation- radial nerve

Question 8

Extensor carpi radialis brevis

Answer 8

(C6-8)

attachments- from the lateral epicondyle of the humerus (common extensor origin) to the base of the 3rd metacarpal

actions- extends & abducts hand at wrist (radial deviation)

innervation- radial nerve

Question 9

Extensor carpi radialis longus

Answer 9

(C6-8)

attachments- from the lateral supracondylar ridge of the humerus to the base of the 2nd metacarpal

actions- extends & abducts hand at wrist (radial deviation) & assists in flexion of the elbow

innervation- radial nerve

Question 10

Extensor carpi ulnaris

Answer 10

(C6-8)

attachments- from the lateral epicondyle of the humerus (common extensor origin) to the base of the 5th metacarpal

actions- extends & adducts hand at wrist (ulnar deviation)

innervation- radial nerve

Question 11

Extensor digitorum

Answer 11

(C6-8)

attachments- from the lateral epicondyle of the humerus (common extensor origin) to the extensor expansions of digits 2-5

actions- extends phalanges (primarily at metacarpophalangeal, secondarily at interphalangeal) & hand at wrist

innervation- radial nerve

Question 12

Extensor digiti minimi

Answer 12

(C7-8)

attachments- from the lateral epicondyle of the humerus (common extensor origin) to the digital expansion of the 5th digit

actions- extends 5th digit (metacarpophalangeal & interphalangeal)

innervation- radial nerve

Question 13

Extensor indicis

Answer 13

(C7-8)

attachments- from the posterior surface of the ulna & interosseous membrane to the digital expansion of the 2nd digit

actions- extends 2nd digit (metacarpophalangeal & interphalangeal)

innervation- radial nerve

Question 14

Extensor pollicis brevis

Answer 14

(C6-8)

attachments- from the posterior radial surface & interosseous membrane to the base of the 1st proximal phalanx

actions- extends thumb (metacarpophalangeal) & extends & abducts CMC joint

innervation- radial nerve

Question 15

Extensor pollicis longus

Answer 15

(C6-8)

attachments- from the middle 1/3rd of the posterior surface of the ulna & interosseous membrane to the base of the 1st distal phalanx

actions- extends thumb (CMC & metacarpophalangeal & interphalangeal)

innervation- radial nerve

Question 16

Flexor carpi radialis

Answer 16

(C6-8)

attachments- from the medial epicondyle (common flexor origin) to the palmar aspect of the base of the 2nd metacarpal

actions- flexes & abducts hand at wrist (radial deviation) & may assist in pronation of forearm & flexion of the elbow

innervation- median nerve

Question 17

Flexor carpi ulnaris

Answer 17

(C7-T1)

attachments- from the medial epicondyle (common flexor origin) of the humerus & proximal ulnar shaft to the pisiform

actions- flexes & adducts hand at wrist (ulnar deviation) & assists in flexion of the elbow

innervation- ulnar nerve

Question 18

Flexor digitorum profundus

Answer 18

(C7-T1)

attachments- from the anterior proximal two thirds of the ulna & interosseous membrane to the base of the distal phalanges of digits 2-5

actions- flexion of digits 2-5 (metacarpophalangeal & distal interphalangeal & proximal interphalangeal), & flexion of hand at wrist

innervation- median (anterior interosseous nerve; 2nd & 3rd digits) & ulnar (4th & 5th digits) nerves

Question 19

Flexor digitorum superficialis

Answer 19

(C7-T1)

attachments- from the medial epicondyle (common flexor origin) of the humerus to the sides of the middle phalanges of digits 2-5

actions- flexion of digits (metacarpophalangeal & proximal interphalangeal), & hand at wrist

innervation- median nerve

Question 20

Flexor pollicis longus

Answer 20

(C7-T1)

attachments- from the anterior surface of the radius & interosseous membrane to the base of the distal phalanx of the thumb

actions- flexes thumb (metacarpophalangeal & interphalangeal)

innervation- median nerve (anterior interosseous nerve)

Question 21

Palmaris longus

Answer 21

(C7-8)

attachments- from the medial epicondyle of the humerus (common flexor origin) to the palmar aponeurosis

actions- flexes hand at wrist & tenses palmar fascia

innervation- median nerve

Question 22

Pronator quadratus

Answer 22

(C8-T1)

attachments- from the anterior surface of the distal ulna to the anterior surface of the distal radius

actions- pronates the forearm

innervation- median nerve (anterior interosseous nerve)

Question 23

Pronator teres

Answer 23

(C6-7)

attachments- from the medial epicondyle & ulnar coronoid process to lateral aspect of the radius

actions- pronates & flexes forearm

innervation- median nerve

Question 24

Supinator

Answer 24

(C5-6)

attachments- from the lateral epicondyle of the humerus, radial collateral ligament & supinator crest of the ulna to the lateral surface of the proximal radius

actions- supinates forearm

innervation- radial nerve