Muscles of the Carpal and Digital joints

Question 1

Origin of extensors

Answer 1

Lateral epicondyle, exept for M. extensor carpi radialis

Question 2

Origin of flexors

Answer 2

Medial epicondyle

Question 3

Origin of M. extensor carpi radialis

Answer 3

Crista supracondylaris lateralis of the humerus

Question 4

Insertion of M. extensor carpi radialis

Answer 4

Proximal-dorsal ends of McII and McIII

Question 5

Function of M. extensor carpi radialis

Answer 5

Extension of the CARPUS; Flexion of the ELBOW joint

Question 6

Insertion of M. extensor digitorum communis

Answer 6

Dorsal aspect of the crista unguicularis (P3)

Question 7

Function of M. extensor digitorum communis

Answer 7

Extension of the Carpus and digits II-V

Question 8

Insertion of M. extensor digitorum lateralis

Answer 8

Dorsal aspect of the crista ungicularis (P3) via the tendons of M. extensor digitorum communis

Question 9

Function of M. extensor digitorum lateralis

Answer 9

Extension of digits III-V

Question 10

Insertion of M. extensor carpi ulnaris (M. ulnaris lateralis)

Answer 10

Proximo-lateral end of McV and accessory carpal bone

Question 11

Function of M. extensor carpi ulnaris (M. ulnaris lateralis)

Answer 11

Flexion of the Carpus. The muscle’s insertion lies palmar to the Carpal joint’s axis of rotation - so this muscle looks like an extensor, but actually is a flexor

Question 12

Origin of M. abductor digiti I longus (M. abductor pollicis longus)

Answer 12

Lateral surfaces of the Radius and Ulna

Question 13

Insertion of M. abductor digiti I longus (M. abductor pollicis longus)

Answer 13

Proximo-medial end of McI. there is a sesamoid bone in the tendon of insertion

Question 14

Insertion of M. flexor carpi radialis

Answer 14

Proximo-palmar ends of McII and McIII

Question 15

Function of M. flexor carpi radialis

Answer 15

Flexion of the Carpus

Question 16

Insertion of M. flexor digitorum superficialis

Answer 16

Palmar tubercules proximally on P2 of digits II-V

Question 17

Function of M. flexor digitorum superficialis

Answer 17

Flexion of the metacarpophalangal joint and proximal interphalangal joint (i.e. between P1 and P2) of digits II-V; Flexion of the Carpus

Question 18

Insertion of M. flexor carpi ulnaris

Answer 18

Distal end of the Os carpi accessorium

Question 19

Function of M. flexor carpi ulnaris

Answer 19

Flexion of the Carpus; Passive support of the Carpus and prevention of excessive over-extension when weight-bearing

Question 20

Insertion of M. flexor digitorum profundus

Answer 20

Tuberculum flexorium of P3 of digits I-V

Question 21

Function of M. flexor digitorum profundus

Answer 21

Flexion of the digits (all joints) and Carpus

Question 22

Origin of Mm. interossei

Answer 22

Palmar carpal fibrocartilage and proximo-palmar ends of McII-V

Question 23

Insertion of Mm. interossei

Answer 23

Proximo-palmar ends of P1 of digits II-V

Question 24

Function of Mm. interossei

Answer 24

Flexion of the metacarpophalangeal joint