Extrinsic Muscles of the Hand

Question 1

Flexor Carpi Radialis (FCR)

Answer 1

- superficial
Attachments:
Origin = medial epicondyle
Insertion = base of 2nd + 3rd MC
Actions:
- Flexes elbow, wrist, CMC of 2 + 3, also radially deviates

Question 2

Flexor carpi ulnaris (FCU)

Answer 2

- superficial
Attachments:
Origin = medial epicondyle 
Insertion = pisiform + base of 5th MC
Actions: 
Flexes elbow, wrist, CMC of 5, also ulnar deviates

Question 3

Palmaris longus (PL)

Answer 3

- superficial
Attachments: 
Origin = medial epicondyle 
Insertion = palmar fascia 
Actions: 
Flexes elbow, wrist (assists w/ wrist = not a very strong flexor)

Question 4

Flexor digitorum superficialis (FDS)

Answer 4

• superficial
  Attachments:
  Origin = medial epicondyle + UCL + cornoid process
  Insertion = middle phalanges 2,3,4,5
  Actions:
  Flexes elbow, wrist, CMC + MCP + PIP of 2-5

Question 5

Pronator teres

Answer 5

- superficial
Attachments: 
Origin = medial epicondyle + proximal ulna 
Insertion = mid-shaft lateral radius
Actions:
Flexes elbow, pronates forearm

Question 6

Flexor digitorum profundus (FDP)

Answer 6

- deep
Attachments: 
Origin = Ulna + IO membrane 
Insertion = distal phalanges of 2-5
Actions: 
Flexes wrist, MCP’s, PIP’S + DIP’s of 2-5

Question 7

Flexor pollicus longus (FPL)

Answer 7

- deep
Attachments: 
Origin = radius + IO membrane 
Insertion = distal phalanx 1 
Actions: 
Flexes MCP’s + IP’s of 1
= thumb flexor

Question 8

Pronator quadratus

Answer 8

- deep
Attachments:
Origin/ insertion = radius to ulna (distal + anterior surface)
Actions: 
Pronates the forearm

Question 9

Extensor carpi radialis longus (ECRL)

Answer 9

• superficial
  Attachments:
  Origin = lateral epicondyle + supracondylar ridge
  Insertion = base of MC 2
  Actions:
  Extends elbow, wrist + CMC 2, radially deviates

Question 10

Extensor carpi radialis brevis (ECRB)

Answer 10

- superficial 
Attachments:
Origin = lateral epicondyle
Insertion = base of MC 3
Actions: 
Extends elbow, wrist + CMC of 3, radially deviates

Question 11

Extensor digitorum (ED)

Answer 11

- superficial
Attachments: 
Origin = lateral epicondyle 
Insertion = DDE of 2-5
Actions: 
Extends elbow, wrist, CMC, MCP’s + both sets of the IP’s of 2-5

Question 12

Extensor digiti minimi (EDM)

Answer 12

- superficial 
Attachments: 
Origin = lateral epicondyle
Insertion = DDE of 5
Actions: 
Extends elbow, wrist + CMC, MCP, IP of 5

Question 13

Extensor carpi ulnaris (ECU)

Answer 13

- superficial 
Attachments:
- Origin: lateral epicondyle
- Insertion: MC 5
Actions: 
Extends elbow, wrist + CMC of 5, ulnar deviates

Question 14

Abductor pollicis longus (APL)

Answer 14

- deep
Attachments: 
Origin = proximal forearm 
Insertion = base of MC 1
Actions:
CMC joint of 1: thumb abduction + extension

Question 15

Extensor pollicis brevis (EPB)

Answer 15

- deep 
Attachments:
Origin = distal forearm
Insertion = proximal phalanx 1 
Actions: 
CMC + MCP of 1 extension

Question 16

Extensor pollicis longus (EPL)

Answer 16

- deep
Attachments:
Origin = proximal forearm
Insertion = distal phalanx 1 
Actions: 
CMC + MCP + IP extension of digit 1

Question 17

Extensor indicis (ED)

Answer 17

- deep
Attachments: 
Origin = distal forearm 
Insertion = DDE of phalanx 2
Actions: 
Extends wrist, CMC + MCP + both IP’s of phalanx 2