Muscles - Upper Limb Forearm

Question 1

Supinator Muscle (SM)

Answer 1

Origin: Lateral epicondyle of humerus, supinator fossa of ulna

Insertion: Anterior, lateral and posterior of third down the radius

Action: Supinates forearm at radioulnar joint

Question 2

Extensor Pollicis Brevis (EPB)

Answer 2

Origin: Posterior radius, into interosseous membrane of forearm

Insertion: Base of proximal phalanx of thumb

Action: Extends thumb

Question 3

Pronator Quadratus (PQ)

Answer 3

Origin: Anterior of distal quarter of ulna Insertion: Anterior of distal quarter of radius Action: Pronates forearm at radioulnar joint

Question 4

Flexor Digitorum Profundus (FDP)

Answer 4

Origin: Medial aspect of the Coronoid process Insertion: Palmar side of base of distal phalanges of all 4 fingers Action: Flexion of index, middle, ring and little finger

Question 5

Flexor Pollicis Longus (FPL)

Answer 5

Origin: Anterior radius, adjacent interosseous membrane of forearm Insertion: Distal thumb phalanx Action: Flexes thumb

Question 6

Extensor Indicis (EI)

Answer 6

Origin: Posterior ulna, interosseous membrane Insertion: Extensor hopd of index finger on medial side of tendon of extensor digitorum Action: Extension of index finger

Question 7

Extensor Carpi Radialis Brevis (ECRB)

Answer 7

Origin: Common extensor origin on lateral epicondyle Insertion: Posterior base of second metacarpal Action: Extension at wrist, abducts at radiocarpal and midcarpal joints

Question 8

Abductor Pollicis Longus (APL)

Answer 8

Origin: Posterior surfaces of radius and ulna, interosseous membrane Insertion: Radial side of base of first metacarpal Action: Radial abduction of thumb and extends carpometacarpal joint

Question 9

Extensor Pollicis Longus (EPL)

Answer 9

Origin: Posterior surface of ulna and IM Insertion: Distal phalanx of thumb Action: Extends all joints of thumb

Question 10

Extensor Pollicis Longus (EPL)

Answer 10

Origin: Posterior surface of ulna, interosseous membrane Insertion: Base of distal phalanx of thumb Action: Extends thumb

Question 11

Abductor Pollicis Longus (APL)

Answer 11

Origin: Posterior proximal half of ulna and middle of radius, interosseous membrane Insertion: Lateral base of first metacarpal bone Action: Abducts/extends thumb at first carpometacarpal joint

Question 12

Extensor Carpi Radialis Brevis (ECRB)

Answer 12

Origin: Common extensor origin (lateral epicondyle of humerus) Insertion: Dorsal base of third metacarpal bone Action: Extends hands at radiocarpal joint, abducts hand at radiocarpal and midcarpal joints

Question 13

Extensor Carpi Radialis Longus (ECRL)

Answer 13

Origin: Lateral supracondylar ridge of humerus Insertion: Dorsal surface of base of 2nd metacarpal bone Action: Extends hands at radiocarpal joint, abducts hand at radiocarpal and midcarpal joints

Question 14

Flexor Digitorum Superficialis (FDS)

Answer 14

Origin: Medial epicondyle of humerus (humeroulnar joint) via the common flexor tendon, the ulnar collateral ligament and coronoid process of ulna, AND the proximal anterior radius, FORMS ARCH Insertion: Palmar, middle of phalanges of all 4 fingers Action: Flexes 4 fingers

Question 15

Flexor Carpi Radialis (FCR)

Answer 15

Origin: Common extensor origin Insertion: Palmar bases of 2nd and 3rd metacarpal bones Action: Flexes at radiocarpal joint, abducts hands at radiocarpal and midcarpal joints

Question 16

Flexor Carpi Ulnaris (FCU)

Answer 16

Origin: Medial epicondyle of humerus (common flexor tendon), proximal 2/3 of ulna, olecranon of ulna Insertion: Pisiform, hook of hamate, palmar base of 5th metacarpal bone Action: Flexes/adducts hand at radiocarpal joint

Question 17

Extensor Carpi Ulnaris (ECU)

Answer 17

Origin: Common extensor origin and Olecranon on posterior of ulna Insertion: Medial aspect of base of 5th metacarpal Action: Extends/adducts wrist joint

Question 18

Extensor Digiti Minimi (EDM)

Answer 18

Origin: Common extensor origin Insertion: Ulnar (medial) side of extensor digitorum tendon and extensor hood of little finger Action: Extends little finger and aids wrist extension

Question 19

Pronator Teres (PT)

Answer 19

Origin: Common flexor origin AND ulnar head from coronoid process of ulna Insertion: Mid-shaft of radius Action: Pronates the forearm

Question 20

Extensor Digitorum (ED)

Answer 20

Origin: Common extensor origin Insertion: Extensor hood of all 4 fingers Action: Extends all fingers at metacarpophalangeal and interphalangeal joints

Question 21

Palmaris Longus (PL)

Answer 21

Origin: Common Flexor Origin Insertion: Flexor retinaculum and palmar aponeurosis Action: Weak wrist flexor (often used for tendon grafting in surgery)

Question 22

Brachioradialis

Answer 22

Origin: Proximal aspect of lateral supracondylar ridge of humerus Insertion: Lateral part of distal radius Action: Flexing elbow at mid-prone position

Question 23

Anconeus Muscle

Answer 23

Origin: Posterior lateral epicondyle of humerus Insertion: Olecranon, proximal end of ulna Action: Extends forearm