wrist/hand Flashcards
ext retinaculum hood mechanism?
?
volar plate prevents…
hyperext
hand accounts for % of upper limb function
90
thumb is involved in % of hand function
40-50
functional ROM of wrist
10 ext
30-35 degrees flex
functional position
20 wrist ext 10 ulnar dev 45 MCP flex 30 PIP flex slight DIP flex
distal RU joint
TFCC (triangular fibrocartilage complex: includes disc and ligaments) helps stabilize
distal RU positions
open-10 sup
closed- 5 sup
capsular pattern- pronation=supination, pain at extremes of pro/sup
TFCC
triangular fibrocartilage complex (includes disc and ligaments) helps stabilize
fibrocartilage disc between distal ulna and carpals in medial wrist
dorsal and volar radio-ulnar lig
ulnar-carpal lig
enhance joint congruity and cushion against compressive forces (transmits about 20% load from hand to forearm)
ECU attaches to TFCC
can get torn
popping and clicking
radiocarpal joint
distal end of the radius, scaphoid, lunate and the TFCC
open- 10 wrist flex and slight ulnar dev
closed- full ext with radial dev
capsular pattern- equal limitation all directions
midcarpal joint
proximal-scaphoid, lunate, triquetrum
distal- trapezium, trapezoid, capitate, hamate
open- neutral or slight flex with ulnar dev
closed-ext with ulnar dev
capsular pattern- equal limitations in all directions
first CMC joint
articulation between 1st metacarpal and trapezium
saddle/sellar joint
open- mid abd/add/flex/ext
closed-full opposition
capsular-abd most limited, followed by extension
CMC 2-5
open- neutral position of wrist
closed- not described
capsular pattern- equal limitation in all directions
MCP 1st digit
open- slight flex
closed- maximal opposition
capsular pattern- greater limitation in flex than ext
MCP, PIP, DIP, 2-5
MCP open- slight flex closed- full ext capsular pattern- equal restriction in all directions PIP open- slight flex closed-full ext capsular pattern- greater limitation in flex than ext DIP open- slight flex closed-full ext capsular pattern- greater limitation in flex than ext
extensor retinaculum
prevents tendons from bowstringing
forms 6 compartments
extensor hood
complex tendon covering post aspect of the digits
combination of ED,EI,EDM
distal portion of hood receives tendons of lumbricles and interossei over prox phalanx
between MCP and PIP, complete tendon splits into 3 parts: central slip and 2 lateral bands
arrangement creates cable system for ext MCP and IP joints
oblique retinacular ligament (ORL)
runs from solar side proximal to PIP - dorsal terminal extensor tendon
links DIP and PIP movement
can measure length: measure DIP flex with PIP ext and measures DIP flex with PIP flex
contracture ORL- increased DIP flex with PIP flexed
unchanged- joint capsule contracture
flexor retinaculum
flexor retinaculum- between pisaform, hamate, scaphoid, and trapezium
serves as attachment site for thinner and hypothenar muscles
maintains transverse carpal arch
acts as restraints against bowstringing of flexor tendons
protects median N
flexor pulleys
annular and cruciate connective tissues restrain flexor tendonos to metacarpals and phalanges, contribute to tunnels through which the tendons travel
volar plate
very thick fibrocartilage band which joins 2 bones in the finger, reinforces joint capsule
9 structures that go through carpal tunnel
4 FDP, 4 FDS, median N, FPL
carpal bones
numerous ligaments
pisaform has 2 attachments- FCU is the only extrinsic forearm muscle to insert on carpal bone and abductor digit minim also inserts
tenodesis
passive hand grip and release mechanism, effected by wrist flexion or extension
moving the wrist in ext will cause the fingers to curl or grip
moving the wrist in flex will cause fingers to straighten or release
tunnels
carpal- median N and 9 flexor tendons
tunnel of guyon- located between hook of hamate and pisiform
passageway for ulnar N and artery into the hand
arches
proximal transverse- carpal bones, rigid, immobile
distal transverse- heads of metacarpals, mobile
longitudinal- flex, mobile