This document provides an overview of wrist and hand anatomy including bones, articulations, ligaments, muscles, and biomechanics. It describes the 8 carpal bones and their articulations in the wrist. Numerous ligaments provide support between carpal bones and from the carpus to the radius and ulna. Extrinsic and intrinsic muscles are outlined along with their origins, insertions, innervations and functions in moving the wrist, thumb, and fingers. Biomechanics sections explain mechanisms of finger flexion and extension.

1. Wrist and Hand Anatomy

2. Bone Anatomy
• Scapoid
• Lunate
• Triquetrium
• Pisiform
• Trapeziod
• Trapezium
• Capitate
• Hamate

3. Wrist Articulations
• Radiocarpal Joint
– Proximal portion
– Distal portion
– Most surface contact
found

4. Articulations
• Midcarpal Joint
– Articulation between
proximal and distal row
of carpals
– Not an uninterupted joint
– Distal Row
• 2 degrees of freedom
• Moves as a fixed unit

5. Ligament Support
• Volar Carpal Ligaments
– Volar Radiocarpal
Ligament
• Three bands
– Volar Ulnocarpal
Ligament
– Scapholunate
Interosseous Ligament
– Lunotriquetral Ligament

6. Ligament Support
• Dorsal Carpal Ligaments
– Dorsal Radiocarpal
Ligament
– Dorsal Intercarpal
Ligament
– Radial Collateral
Ligament
– Ulnar Collateral Ligament

7. Triangular Fibrcartilage Complex
• Composition
• Role

8. Hand

9. Carpometacarpal (CMC) Joints of 2-5
• Composition
• Carpal Arch

10. Carpometacarpal (CMC) Joints of 2-5
• Composition
• Carpal Arch
• Ligament Support
– Transverse Carpal
Ligament
– Dorsal and Palmar CMC
Ligaments
– Dorsal and Palmar
Metacarpal Ligaments
– Metacarpal Interosseous
Ligaments

11. Carpometacarpal (CMC) Joints of 2-5
• Composition
• Carpal Arch
• Ligament Support
– Transverse Carpal Ligament
– Dorsal and Palmar CMC
Ligaments
– Dorsal and Palmar Metacarpal
Ligaments
– Metacarpal Interosseous
Ligaments
• Movement of CMC Joints

12. Metacarpophalangeal (MCP) Joints
of 2-5 Fingers
• Ligament Support
– Capsule
– Volar Plate
– Collateral Ligaments
– Motions

13. Interphalangeal Joints of 2-5 Fingers
• Hinge Joints
• Motions

14. Thumb

15. CMC of Thumb
• Saddle Joint
• Ligament Support
– Capsule
– Intermetacarpal Ligament

16. MCP of Thumb
• Ligament Support
• IP Joint of Thumb

17. Extrinsic Hand Muscles

19. Extensor Indicis
• O
– Dorsal surface lower ½ body
of ulna
– Interosseus membrane
• I
– Ulnar side of index finger’s
EDC tendon
• N
– Radial (posterior interosseus)
• F
– MCP and IP Ext of 2nd digit

20. Extensor Pollicis Longus
• O
– Posterior 1/3 ulna
– Interosseus membrane
• I
– Posterior surface of base of
thumb distal phalanx
• N
– Radial (posterior interosseus)
• F
– CMC, MCP and IP Ext of 1st
digit

21. Extensor Pollicis Brevis
• O
– Dorsal 2/3 of radius
• I
– Dorsal surface of base of
proximal 1st phalanx
• N
– Radial (posterior interosseus)
• F
– CMC & MCP Ext of thumb
– CMC ABD of thumb

22. Abductor Pollicis Longus
• O
– Posterior distal 2/3 of ulna
– Posterior middle 1/3 of radius
– Interosseus membrane
• I
– Radial side of base of 1st
metacarpal
• N
– Radial (posterior interosseus)
• F
– CMC ABD & Ext of thumb

23. Flexor Pollicis Longus
• O
– Anterior middle ½ of radius
– Interosseus membrane
• I
– Palmar surface of base of distal
1st phalanx
• N
– Median (anterior interosseus)
• F
– IP Flexion of thumb

24. Extensor Digiti Minimi
• O
– Lateral epicondyle of
humerus
• I
– Extensor expansion of 5th
digit
• N
– Radial (posteior
interosseus)
• F
– MCP and IP extension of
5th digit

25. Flexor Digitorum Superficialis
• O
– Medial epicondyle of humerus
– Coronoid process
– Middle ½ anterior radius
• I
– Four tendons separating into
two parts that insert into sides
of bases of middle 2-5
phalanxes
• N
– Median
• F
– MCP flexion digits 2-5
– PIP flexion digits 2-5

26. Flexor Digitorum Profundus
• O
– Anteriomedial surface of ulna
– Interosseus membrane
• I
– Four tendons inserting into
distal phalanxes of digits 2-5
• N
– Media 2-3 digits
– Ulna 4-5 digits
• F
– DIP flexion of 2-5 digits

27. Intrinsic Hand Muscles
Thenar Eminance

28. Abductor Pollicis Brevis
• O
– Scaphoid tuberosity
– Trapezium ridge
– Transverse carpal ligament
• I
– Lateral base f proximal 1st
phalanx
• N
– Median
• F
– CMC & MCP ABD of thumb

29. Flexor Pollicis Brevis
• O
– Superficial head – trapezium
– Deep head – trapezoid,
capitate and palmar ligaments
of distal carpal bones
• I
– Base of prximal 1st phalanx on
radial side
– Extensor expansion
• N
– Superficial – median
– Deep – Ulnar
• F
– CMC & MCP Flexion of
thumb

30. Opponens Pollicis
• O
– Trapezium
– Transverse Carpal
Ligament
• I
– Radial side of 1st
metacarpal shaft
• N
– Median
• F
– Opposition

31. Intrinsic Hand Muscles
Hypothenar Eminence

32. Abductor Digiti Minimi
• O
– Pisiform
• I
– Ulnar side base of 5th
proximal phalanx
• N
– Ulnar
• F
– MCP ABD of 5th digit

33. Opponen Digiti Minimi
• O
– Hook of hamate
– Transverse carpal ligament
• I
– Ulnar border of entire 5th
metacarpal bone
• N
– Ulnar
• F
– MCP flexion & rotation of 5th
digit

34. Flexor Digiti Minimi
• O
– Hamate bone
– Transverse carpal
ligament
• I
– Ulnar side of proximal 5th
phalanx
• N
– Ulnar
• F
– MCP Flexion of 5th digit

35. Other Intrinsic Hand
Muscles

36. Adductor Pollicis
• O
– Oblique Head
• Capitate bone
• Bases of 2-3 metacarpals
– Transverse Head
• Proximal 2/3 of palmar
surface of 3rd metacarpal
• I
– Ulnar side of base of 1st
proximal phalanx
• N
– Ulnar
• F
– CMC ADD of thumb

37. Palmar Interossei
• O
– 1st – ulnar side base of 1st
metacarpal bone
– 2nd – ulnar side of 2nd MC
bone
– 3rd – radial side of 4th MC bone
– 4th – radia side of 5th MC bone
• I
– Extensor expansion of 2,4 and
5th digits
• N
– Ulnar
• F
– ADD of 1st, 2nd, 4th and 5th
digits toward midline of hand

38. Dorsal Interossei
• O
– 1st lateral head – ulnar side of
1st metacarpal bone
– 1st medial head – radial side of
2nd metacarpal bone
– 2nd, 3rd, 4th space between
metacarpal bones
• I
– 1st – radial side 2nd proximal
phalanx
– 2nd – radial side of 3rd
– 3rd – ilnar side of 3rd
– 4th – ulnar side of 4th
• N
– Ulnar
• F
– ABD of 2nd, 3rd, and 5th finger
from midline

39. Lumbricales
• O
– Tendons of FDP
• I
– Extensor expansion on dorsal
aspect of each digits radial side
• N
– 1 and 2 – median
– 3 and 4 – ulnar
• F
– MCP flexion 2-5 digits
– DIP & PIP ext 2-5 digits

40. Palmaris Brevis
• O
– Flexor retinaculum
• I
– Palmar surface skin on
ulnar side of hand
• N
– Ulnar
• F
– Wrinkles skin of hand on
ulnar side

41. Biomechanics of Hand

42. Biomechanics of Finger Flexion
• Gliding mechanisms
– Retinaculae
– Ligaments
– Bursa
– Digital tendon sheaths
• Annular Pulleys
– A1-A5
• Cruciate Ligaments
– C1-C3
• Function of Pulleys

43. Biomechanics of Finger Extension
• Extensor Hood
– EDC tendons
– DI and PI tendons
– Lumbricales
– Central tendon
– Oblique Retinacular
Ligaments
– Sagittal Bands
• Effects on MCP joints
• Effects on IP Joints