MA II: Wrist and hand Flashcards
Lister’s tubercle of the radius separates tendons of the
EPL/ECRB
carpal bones
- Proximal row: scaphoid, lunate, triquetrum, pisiform
- Loosely joined
- Distal row: trapezium, trapezoid, capitate, hamate
- Distal row bound tightly by ligaments
Axis of rotation for all wrist movement passes thru the
capitate
(Capitate and 3rd metacarpal function single column stability)
the first metacarpal articulates with
trapezium
Joints of the wrist
- Radiocarpal joint: concave distal radius and convex scaphoid and lunate (an triquetrum in full ulnar deviation)
- Midcarpal joint
- Intercarpal joints
arthrokinematics of the radiocarpal and mid-carpal joints during flexion/extension
- lunate and radius roll and slide in opposite direction
- capitate and lunate roll and slide in opposite directions
arthrokinematics of the radiocarpal joint during ulnar deviation
- Scaphoid, lunate, triquetrum roll ulnarly
- Slide radially (over the radius)
- The midcarpal also roll and slide in opposite directions
Primary wrist extensors
- 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
primary wrist flexors
- FCR
- FCU (greatest torque)
- PL
In the hand, “concave on convex, lets you flex, ____ times”
15
except 1st CMC abduction/adduction
what dictates the splinting position in the PIP and DIP joints of the hand?
the palmar plates
therefore splint PIP and DIP in extension
what dictates the splinting position in the MCP joints of the hand?
collateral ligaments
(splint in flexion)