Wrist & Hand

Question 1

What are the muscles of the hand?

Answer 1

Intrinsic:
Thenar: Abductor pollicis brevis, flexor pollicis brevis, opponens pollicis brevis
Adductor pollicis
Hypothenar: opponens digiti minimi, flexor digiti minimi, abductor digiti minimi

Extrinsic: FDP, FDS, FPL, APL, EPL, ED, EI, EDM

Question 2

Identify the joints of the hand and their synovial classification.

Answer 2

Proximal radioulnar - ellipsoidal
Carpometacapral (CMC) - pivot
Metacarpophalangeal (MP) -ellipsoidal
Proximal Interphalangeal (PIP) - hinge
Distal Interphalangeal (DIP) - hinge
Interphalangeal (IP) of thumb - saddle

Question 3

Identify the functions and attachments of the ligaments of the wrist and hand.

Answer 3

Wrist:
Dorsal and palmar Radioulnar ligament 
Radial Collateral ligament
Ulnar Collateral ligament
Lunotriquetral, scapholunate ligament, etc.

Hand: 
Radial/Ulnar Collateral: MP, PIP, DIP
Proximal attachment - dorsal surface
Distal attachment - palmar surface
Palmar ligament on palmar plate

Question 4

Summarize collateral circulation at the hand.

Answer 4

See drawing

Question 5

Locate surface features of the wrist and hand.

Answer 5

.

Question 6

Describe the carpal bones.

Answer 6

Proximal Row: Scaphoid, Lunate, Triquetrum, Pisiform

Distal Row: Trapezium, Trapezoid, Capitate, Hamate

Question 7

Name and demonstrate the actions (motions) at the wrist.

Answer 7

Flexion, Extension, Radial/Ulnar Deviation

Question 8

Describe the attachments and functions of the transverse carpal ligament.

Answer 8

Portion of flexor retinaculum
Attachments:
Ulnar - hook of hamate and pisiform
Radial - trapezium and scaphoid

Functions: 
Attachment for thenar and Hypothenar muscles
Maintains carpal arch
Prevents bowstringing of flexor tendons
Protects median n.

Question 9

Describe the structure and function of the triangular fibrocartilage complex (TFCC).

Answer 9

Structure: 
Triangular in shape
Analogous to meniscus in knee
Shock absorption
Fibrocartilage - degenerates over time
Distal to ulna

Function: stabilizes ulna and carpals

Question 10

Name the components formed by the extensor retinaculum and the tendons found within each.

Answer 10

APL, ECRL, ECRB, EPL, ED, EI, EDM, ECU

Function: helps create optimum line of pull for motions done with thumb

Question 11

Name the bones of the hand.

Answer 11

Carpals, metacarpals, phalanges

Question 12

Name the joints of the hand.

Answer 12

Carpometacarpal (CMC)
Metacarpophalangeal (MP)
Proximal interphalangeal (PIP)
Distal interphalangeal (DIP)
Interphalangeal (IP) of thumb

Question 13

Name and demonstrate the actions (motions) of the fingers and thumb.

Answer 13

Finger
MP Joints: ab/adduction, flexion/extension, rotate (conjunct)
PIP/DIP Joints: flexion/extension

Thumb
CMC: radial ab/adduction, palmar ab/adduction, opposition/reposition
MP joint: flexion/extension
IP joint: flexion/extension

Question 14

Describe the structure of the palmar fascia and digital fascia sheaths.

Answer 14

Palmar Fascia: continuous with antebrachial fascia, thenar fascia, Hypothenar fascia, palmar aponeurosis

Digital Fascia Sheaths: pulleys
- anular: straight
- cruciate: crossed
Function: maintain relationship of flexor tendons to bone
Prevent bowstringing of tendons

Question 15

Describe the structure and function of the juncturae tendinae.

Answer 15

Structure: intertendinous connections of ED
Function: distributes forces between extensor tendons to prevent rupture

Question 16

Differentiate between muscles that are found in the forearm (extrinsic) and the hand (intrinsic).

Answer 16

Extrinsic: FDP, FDS, FPL, APL, EPL, ED, EI, EDM
Intrinsic: Thenar (abductor pollicis brevis, flexor pollicis brevis, opponens pollicis brevis), adductor pollicis, Hypothenar (opponens digiti minimi, flexor digiti minimi, abductor digiti minimi)

Question 17

Describe the location and function of the ligaments of the finger (phalanges).

Answer 17

Radial/Ulnar Collateral Ligament: MP, PIP, DIP
Proximal attachment - dorsal surface
Distal attachment - palmar surface
Function: taught in flexion (lengthens), lax in extension (shortens)

Question 18

Explain what muscles attach to the extensor mechanism/expansion/hood and how they move the finger because of this attachment.

Answer 18

Attachments: ED, juncturae tendinae, transverse retinacular ligament, oblique retinacular ligament
Function: structures work together for extension of fingers

Question 19

Review the peripheral nerve supply/distribution of the following nerves: radial, median, and ulnar.

Answer 19

Hand:
Median N.: thenar mm (recurrent branch), 1st & 2nd lumbricals
Ulnar N: Hypothenar mm, adductor pollicis, deep head flexor pollicis brevis, 3rd & 4th lumbricals, dorsal and palmar interossei
Radial N: none

Wrist:
Median N: anterior compartment and radial side of hand
Ulnar N: some thenar, all interossei, all Hypothenar, some lumbricals
Radial N: extensor supinator group - no muscles of hand

Question 20

Name the boundaries and contents of the anatomical snuff box.

Answer 20

Boundaries:
Dorsal - EPL (3rd extensor compartment)
Palmar - APL & EPB (1st extensor compartment)
*Scaphoid is floor

Question 21

Describe the underlying anatomy associated with carpal tunnel syndrome.

Answer 21

Median n. Compression at the wrist Transverse carpal ligament

Question 22

Identify structures on Hypothenar Eminence level.

Answer 22

Kenhub

Question 23

Describe sensory nerve distribution.

Answer 23

Radial N: dorsal surface of thumb and most of radial aspect of hand
Ulnar N: palmar and dorsal surface
Median N: palmar thumb and digits 2& 3, dorsal digits 2-4 tips