1. Muscles of the Extremities
Justin R. Stone
AH 129
Tortora: Ch 11

2. Muscles: Flexors and Extensor of the Wrist and Fingers A COMPLETE LIST

3. Upper Extremity
Flexor Carpi Radialis
Palmaris Longus
Flexor Carpi Ulnaris
Flexor Digitorum Superficialis
Flexor Pollicis Longus
Flexor Digitorum Profundus
Extensor Carpi Radialis Longus
Extensor Carpi Radialis Brevis
Extensor Digitorum
Extensor Digiti Minimi
Extensor Carpi Ulnaris
Abductor Pollicis Longus
Extensor Pollicis Brevis
Extensor Pollicis Longus
Extensor Indicis

4. Digit = Phalynx (Finger) Pollicis = Thumb
General Info: Terms
Learn these latin terms, and your life will be made MUCH easier in learning the muscles we cover today.
Carpi = Wrist
Digit = Phalynx (Finger)
Pollicis = Thumb
Minimi = Smallest (referring to 5th finger)
Indicis = 2nd Finger (Index Finger)
Radialis = Radius
Ulnaris = Ulna
Palmar = Palm
Dorsal = Posterior

5. General Info: Terms Review

6. General Info: Bone Review

7. General Info: Terms Flexor Wad Extensor Wad
The group of muscles that attaches on / near the Medial Epicondyle
Share the common insertion on the
“Common Flexor Tendon”
All Flex the wrist or fingers
Extensor Wad
The group of muscles that attaches on / near the Lateral Epicondyle
“Common Extensor Tendon”
All Extend the wrist or fingers

8. Muscles: Flexors of the Wrist

9. Upper Extremity: Wrist Flexors
Palmaris Longus
Flexor Carpi Radialis
Flexor Carpi Ulnaris

10. Upper Extremity: Wrist Flexors
Palmaris Longus
O/I:
O: Medial Epicondyle
I: Flexor Retinaculum, Palmar Aponeurosis
N: Median
Action:
Important in stability of hand and wrist by controlling tension on the Palmar Aponeurosis
Weakly flexes wrist

11. Palmaris Longus

12. Upper Extremity: Wrist and Finger Flexors
Flexor Retinaculum
Aka: Transverse Carpal Ligament
Forms the roof of the Carpal Tunnel
Most flexors of the fingers pass through the carpal tunnel / under the Flexor Retinaculum
Palmar Aponeurosis
Deep fascia in the center of the Palm

13. Flexor Retinaculum

14. Upper Extremity: Wrist Flexors
Flexor Carpi Radialis
O/I:
O: Medial Epicondyle
I: Proximal 2nd and 3rd Metacarpals
N: Median A:
Flex wrist
Abduct wrist (AKA: Radial Deviation)

15. Flexor Carpi Radialis

16. Upper Extremity: Wrist Flexors
Flexor Carpi Ulnaris
O/I:
O: Medial Epicondyle, SuperoPosterior border of Ulna
I: Pisiform, Hamate, and Proximal 5th Metacarpal
N: Ulnar A:
Flex wrist
Adduct wrist (AKA: Ulnar Deviation)

17. Flexor Carpi Ulnaris

18. Note the orientation of the Wrist Flexors, from
Lateral to Medial:
Flexor Carpi Radialis
Palmaris Longus
Flexor Carpi Ulnaris

19. Upper Extremity: Wrist Flexors
Lab: Wrist Flexors
Color: Netter’s
Color: Sieg and Adams p.34-36
Flashcards
Palpate: O/I of Wrist Flexor Group and Palpate while performing Action

20. Muscles: Flexors of the Fingers

21. Upper Extremity: Finger Flexors (Excluding Intrinsic Hand Muscles)
Flexor Digitorum Superficialis
Flexor Digitorum Profundus
Flexor Pollicis Longus

22. Upper Extremity: Finger Flexors
Flexor Digitorum Superficialis
O/I:
O: 2 Heads
Medial Epicondyle of Humerus
Coronoid Process of Ulna
(Anterior Oblique Line of Radius)
I: 4 separate tendons
Middle Phalynx of Fingers 2-5
N: Median A:
Flexes middle and proximal phalynx
Weakly flexes wrist
*Median nerve passes between the 2 heads of this muscle

23. Flexor Digitorum Superficialis

24. Upper Extremity: Finger Flexors
Flexor Digitorum Profundus
O/I:
O: Antero-medial body of ulna
I: Proximal distal phalanx of fingers 2-5.
N: Median and Ulnar
A: Flexes the following:
DIP and PIP
MCP
Hand and Wrist

25. Flexor Digitorum Profundus

26. Flexor digitorum profundus lies deep to superficialis, but it attaches more distally. To get around this problem profundus's tendons go through the tendons of superficialis, and end up attaching to the distal phalynx.

28. Which is Which?

30. Upper Extremity: Finger Flexors
Flexor Pollicis Longus
O/I:
O: Anterior Radius
O: Interosseus Membrane
I: Proximal distal phalynx of thumb
N: Median
A: Flexes IP of thumb

31. Flexor Pollicis Longus

32. Upper Extremity: Finger Flexors
Lab: Finger Flexors
Color: Netter’s
Color: Sieg and Adams p.40-42
Flashcards
Palpate: O/I of Finger Flexor Group and Palpate while performing Action

33. Muscles: Extensors of the Wrist

34. Upper Extremity: Wrist Extensors
Extensor Carpi Radialis Longus
Extensor Carpi Radialis Brevis
Extensor Carpi Ulnaris

35. Upper Extremity: Wrist Extensors
Common Extensor Tendon
Tendon shared by 4 of the extensor muscles in the forearm.
Attaches to the lateral epicondyle of the humerus.
Serves as an origin, at least in part, for 4 muscles:
Extensor carpi radialis brevis
Extensor digitorum
Extensor digiti minimi
Extensor carpi ulnaris

36. Upper Extremity: Wrist Extensors
Extensor Carpi Radialis Longus
O/I:
O: Lateral Supracondylar Ridge of Humerus
I: Second Metacarpal
N: Radial A:
Extends Wrist
Abducts Wrist (Radial Deviation)

37. Extensor Carpi Radialis Longus

38. Upper Extremity: Wrist Extensors
Extensor Carpi Radialis Brevis
O/I:
O: Lateral Epicondyle of Humerus
I: Third Metacarpal
N: Radial A:
Extends Wrist
Abducts Wrist (Radial Deviation)

39. Extensor Carpi Radialis Brevis

40. Upper Extremity: Wrist Extensors
Extensor Carpi Ulnaris
O/I:
O: Lateral Epicondyle of Humerus
O: Posterior Border of Ulna
I: Fifth Metacarpal
N: Deep Radial A:
Extends Wrist
Adducts Wrist (Ulnar Deviation)

41. Extensor Carpi Ulnaris

42. Upper Extremity: Wrist Extensors
Lab: Wrist Extensors
Color: Netter’s
Color: Sieg and Adams p.31-33
Flashcards
Palpate: O/I of Wrist Extensor Group and Palpate muscle while performing Action

43. Muscles: Extensors of the Fingers

44. Upper Extremity: Finger Extensors
Extensor Digitorum
Extensor Digiti Minimi
Extensor Indicis
Extensor Pollicis Longus
Extensor Pollicis Brevis
Abductor Pollicis Longus

45. Upper Extremity: Finger Extensors
Extensor Digitorum
O/I:
O: Lateral Epicondyle of humerus
I: Distal and Middle phalynx of fingers 2-5
N: Radial
A: Extends DIP, PIP, MCP, (and CMC)

46. Extensor Digitorum

47. Upper Extremity: Finger Extensors
Extensor Digiti Minimi
O/I:
O: Lateral Epicondyle of Humerus
I: Tendon of Extensor Digitorum on 5th Finger
N: Deep Radial
A: Extends 5th MCP (and CMC)

48. Extensor Digiti Minimi

49. Upper Extremity: Finger Extensors
Extensor Indicis
O/I:
O: Posterior surface of ulna
I: Tendon of Extensor Digitorum of 2nd Finger
N: Deep Radial
A: Extends DIP, PIP at MCP of 2nd Finger (and CMC)

50. Extensor Indicis

51. Upper Extremity: Finger Extensors
Extensor Pollicis Longus
O/I:
O: Posterior shaft of Ulna
O: Interosseus Membrane
I: Proximal Distal Phalynx of 1st Finger
N: Deep Radial A:
Extends IP and CMC of Thumb
Abducts Wrist (Radial Deviation)

52. Extensor Pollicis Longus

53. Upper Extremity: Finger Extensors
Extensor Pollicis Brevis
O/I:
O: Posterior shaft of Radius
O: Interosseus Membrane
I: Base of Proximal Phalynx of 1st Finger
N: Deep Radial A:
Extends MCP and CMC of Thumb
(Extends wrist)

54. Extensor Pollicis Brevis

55. Upper Extremity: Finger Extensors
Abductor Pollicis Longus
O/I:
O: Posterior shaft of Radius, Ulna, and Interosseus Membrane
I: First metacarpal
N: Deep Radial A:
Abducts and Extends CMC of Thumb
Abducts Wrist (Radial Deviation)

56. Abductor Pollicis Longus

57. Upper Extremity: Finger Extensors
Lab: Finger Extensors
Color: Netter’s
Color: Sieg and Adams p.37-39, 43-45
Flashcards
Palpate: O/I of Wrist Extensor Group and Palpate muscle while performing Action

58. Homework:
Quiz over first 2 lectures, including the first 23 Muscles
Diagrams
Questions about Innervation, Attachment, and Action
Next Class:
Intrinsic Muscles of the Hand
Upper Extremity Pathology