MA II: Wrist and hand

Question 1

Lister’s tubercle of the radius separates tendons of the

Answer 1

EPL/ECRB

Question 2

carpal bones

Answer 2

• Proximal row: scaphoid, lunate, triquetrum, pisiform
  
  • Loosely joined
• Distal row: trapezium, trapezoid, capitate, hamate
  
  • Distal row bound tightly by ligaments

Question 3

Axis of rotation for all wrist movement passes thru the

Answer 3

capitate

(Capitate and 3rd metacarpal function single column stability)

Question 4

the first metacarpal articulates with

Answer 4

trapezium

Question 5

Joints of the wrist

Answer 5

1. Radiocarpal joint: concave distal radius and convex scaphoid and lunate (an triquetrum in full ulnar deviation)
2. Midcarpal joint
3. Intercarpal joints

Question 6

arthrokinematics of the radiocarpal and mid-carpal joints during flexion/extension

Answer 6

• lunate and radius roll and slide in opposite direction
• capitate and lunate roll and slide in opposite directions

Question 7

arthrokinematics of the radiocarpal joint during ulnar deviation

Answer 7

• Scaphoid, lunate, triquetrum roll ulnarly
• Slide radially (over the radius)
• The midcarpal also roll and slide in opposite directions

Question 8

Primary wrist extensors

Answer 8

• ECRL
• ECRB
• ECU

Functional significance of the wrist extensors is to place the long finger flexors (FDP/FDS) in a better length tension relationship to make a fist with strength

Question 9

primary wrist flexors

Answer 9

• FCR
• FCU (greatest torque)
• PL

Question 10

In the hand, “concave on convex, lets you flex, ____ times”

Answer 10

15

except 1st CMC abduction/adduction

Question 11

what dictates the splinting position in the PIP and DIP joints of the hand?

Answer 11

the palmar plates

therefore splint PIP and DIP in extension

Question 12

what dictates the splinting position in the MCP joints of the hand?

Answer 12

collateral ligaments

(splint in flexion)