1. Forearm, Wrist & Hand Anatomy

2. What’s the hand?
Definitions of hand: verb:   place into the hands or custody of
noun:   ability
noun:   a card player in a game of bridge
noun:   a hired laborer on a farm or ranch
noun:   a member of the crew of a ship
noun:   a position given by its location to the side of an object
noun:   a rotating pointer on the face of a timepiece
noun:   a round of applause to signify approval
noun:   a unit of length equal to 4 inches; used in measuring horses
noun:   one of two sides of an issue
noun:   physical assistance
noun:   something written by hand
noun:   terminal part of the forelimb in certain vertebrates (e.g. apes or kangaroos): "the kangaroo's forearms seem undeveloped but the powerful five-fingered hands are skilled at feinting and clouting"- Springfield (Mass.) Union 
noun:   the cards held in a card game by a given player at any given time
noun:   the (prehensile) extremity of the superior limb

3. ¼ of the motor cortex is devoted to the hand

4. Motions of the Wrist and Hand
Forearm
Flexion
Extension
Supination
Pronation
Wrist
Ulnar deviation
Radial deviation
Circumduction
Hand
Flexion
Extension
Adduction
Abduction
Opposition
Circumduction
*Palmar and Dorsal Side

5. Bony Anatomy of the Forearm
Two Bones that articulate with the elbow (proximal) and the wrist (distal)
Ulna
Larger and longer bone of the two (extension of the humerus). It distally articulates with the triquetrium and lunate via the TFCC.
Ulnar styloid process
Radius
Distal end makes up majority of the wrist articulation
Two articulations -one with the carpal bones and the other with the ulna
Articulates with the scaphoid and lunate
Radial styloid process

6. Hand and Wrist Anatomy 14 phalanges 5 metacarpals 8 carpal bones
2 sesamoid bones (thumb)
5 metacarpals
8 carpal bones
Distal Radius
Forms small ulnar notch to accept the ulnar head
Radial styloid process
Distal Ulna
Ulnar styloid process arises from medial surface
Ulnar head

7. Carpals(flat bones aligned in 2 rows)
Proximal
Scaphoid-most commonly fractures
Lunate-most commonly dislocated
Triquetrum
Pisiform-acts as sesmoid bone
Distal
Trapezium(aligns with 1st metacarpal)
Trapezoid(2nd metacarpal)
Capitate(3rd metacarpal)
Hamate(4th and 5th metacarpal)

8. Anatomy of the Carpal Bones
Wrist is made up of 8 carpal bones
Scaphoid- name is derived from the Greek word skaphe, meaning boat. Most commonly fractured carpal bone
Lunate- Poor blood supply.
Triquetrum- Three sided bone
Pisiform- Sesamoid bone, floating in the flexor carpi ulnaris muscle
Trapezium-Lays between the scaphoid and the thumb’s metacarpal
Trapezoid- Lays at the base of the second metacarpal (index or pointer finger)
Capitate-Largest of the carpal bones
Hamate- Latin word means “hook”.
“She Looks Too Pretty; Try To Catch Her”

10. Anatomy of the Phalanges
5 Metacarpals
Numbered 1-5 starting at the thumb
Or named thumb, index, middle, ring and little finger
Thumb = pollicus
Pinky = digiti minimi
Index = Indicus
Joints
Carpometacarpal (CMC) = carpals to metacarpals
Metacarpophalangeal (MCP) = metacarpals to phalanges
Proximal interphalangeal (PIP) = proximal phalanges to middlephalanges
Distal Interphalangeal (DIP) = middle phalanges to distal phalanges
Collateral ligaments of the IP joints

11. Articulations Distal Radioulnar Formed by ulnar head and ulnar notch
Allows 1 degree freedom of movement
Pronation/supination
Radius glides around the ulna

12. Radiocarpal joint Reinforced by ligamentous thickening
Formed by distal radius articulating with scaphoid, lunate and triangular fibrocartilage disk(TFCC)
Ellipsoid joint (2 degrees freedom)
Flexion/extension
Radial/ulnar deviation

13. Intercarpal Joints
Palmar/dorsal/interosseous ligaments between each carpal
Very little gliding

14. Midcarpal Joints
Proximal/distal carpal row separated by a single joint cavity with small fibrous projections connecting the rows
Limited mobility in flex/ext, radial/ulnar deviation

15. Carpometacarpal Joint (CMC)
MC1/trapezium
MC2/trapezoid
MC3/capitate
MC4and 5/hamate (forms 1 articulation)

16. 1st CMC (thumb) Saddle joint 2 degrees of freedom(3)
Flexion/extension
Abduction/adduction
Accessory rotation
Allows for opposition

17. 2-4 CMC 5th CMC Plane/synovial joint 1 degree freedom 2 degree freedom
Flexion/extension
5th CMC
2 degree freedom
Abduction/adduction

18. Metacarpophalangeal Joint (MCP)
Two degrees freedom of movement
Flexion/extension
Abduction/adduction
Thumb can abduct at any point/fingers only when extended
Collateral ligaments
Varus/valgus force
When fingers are in flexion they tighten and limit abduction/adduction

19. Interphalangeal Joint
One degree freedom of movement
Flexion/extension
Collateral ligaments

21. Muscular Anatomy Wrist Extensors (innervated by radial n.) Superficial
Extensor carpi radialis brevis/longus
Extensor carpi ulnaris
Extensor digitorium
Abductor pollicus longus
Extensor Digiti Minimi
brachioradialis
Deep compartment
Extensor pollicus longus/brevis
Extensor indices
supinator
Secured by extensor retinaculum

22. Wrist flexors (median n.)
Superficial
Flexor carpi radialis
Flexor carpi ulnaris
Palmaris longus
Pronator teres
- Intermediate
Flexor digitorium superficialis
Deep
Flexor digitorium profundus
Flexor pollicis longus
Pronator quadratus

23. Palmar (intrinsic) Thenar Abductor pollicis brevis
Flexor pollicis brevis
Opponens Pollicis
Tendon FPL
Adductor pollicis

24. Hypothenar Abductor digiti minimi Opponens digiti minimi
Flexor digiti minimi brevis

25. Muscles of the Forearm Anterior Muscles
Wrist and Finger Flexors and Wrist Pronators
Flexors of the wrist
Flexor Carpi Radialis = near carpals on radial side
Flexor Carpi Ulnaris = near carpals on ulnar side
Palmaris Longus (absent in about 25% of population)(thumb and little finger opposition)

26. Muscles of the Forearm Anterior Muscles
Pronators
Pronator Teres
Pronator Quadratus

27. Muscles of the Forearm Anterior Muscles
Digit Flexors
Flexor Digitorum Superficialis (share a muscle belly with FDP, why all fingers will move)
Flexor Digitorum Profundus (lumbrical muscles of fingers arise from the distal tendons)
Flexor Pollicis Longus (10% of population the tip of the index and the thumb move together)

28. Muscles of the Forearm Posterior Muscles
Wrist and Finger Extensors and Wrist Supinators
Wrist Extensors
extensor carpi radialis brevis = posterior & radial side, short
extensor carpi radialis longus = posterior & radial side, long
extensor carpi ulnaris = posterior & ulnar side
Finger Extensors (attach at the common extensor tendon on the lateral epicondyle)
extensor digitorum = extends digits
extensor indicis = extends pointer finger
extensor digiti minimi = extends pinky
Thumb Extensors
abductor pollicis longus (Lay hand flat on table and abduct thumb)
extensor pollicis brevis/longus (Lay hand flat on table and extend only the thumb)

30. Nerve Distribution of the Hand

31. Ligaments of the Forearm
Interosseus Membrane- A fibrous sheath that connects the radius and the ulna.
Radiocarpal ligaments-
Volar Radiocarpal ligament
Dorsal Radiocarpal ligament
Ulnar collateral ligaments
Radial collateral ligaments

32. Dorsal Wrist ligaments
Volar Wrist Ligaments

33. Central Lumbricales Palmar aponeurosis Interossei Tendons FDS/FDP
Superficialis (PIP)
Profundus (DIP)
Lumbricales
Radial side profundus tendon(extensor hood)
Flex MP/ext PIP/DIP
Palmar aponeurosis
Interossei
4 palmar/4 dorsal

34. Carpal Tunnel Fibro-osseous structure Tunnel contains 10 structures
Floor is proximal carpal bones
Roof is transverse carpal ligament
Tunnel contains 10 structures
Median n., flexor pollicis longus tendon, 4 slips of flexor digitorium superficialis, flexor digitorium profundus
Compression results in paresthesia 2-4 fingers and decrease grip