Wrist Complex Biomechanics - 3 Flashcards
close chained movement of humeroulnar like hands on table causes blank to move instead of blank
ulna, radius
degrees of freedom at humeroulnar joint
one (hinge)
capitate is the blank of the hand to keep it blank
keystone, supported/stable
central pillar effect in hand is due to what bone
capitate
carpals allow blank movements
flexion/extension, ulnar/radial deviation
aaos flexion value
80
aaos extension value
70
radial deviation aaos value
20
ulnar deviation aaos value
30
rc joint has a single blank surface that accomodates forearm and hand position
biconvex
this is in the proximal carpal row and is a sesamoid bone but is not included in the rc joint
pisiform
fcu blank is increased by pisiform
moment arm
rc joint contributes to blank and blank more than blank and blank
flexion/ulnar dev, extension/radial dev
no blank act directly on the blank joint
rc
ic joints are between all blank bones
carpal
ic joints allow minimal movement to accomodate blank and blank positioning
hand/wrist
ic joints are bound by blank and have little give
ligaments
ic ulnar side is more blank than radial
mobile
blank ligaments are stronger than blank ligaments at ic joints hence why we extend wrists extinctively when we fall
palmar, dorsal
most commonly dislocated carpal due to instability palmarly
lunate
ganglion cyst formation occurs at the proximal pole of the scaphoid because it has no blank
ligament attachment dorsally
ligaments are blank movers
passive
most stable ligaments because there are 3 rather than one like on the dorsal aspect of hand
volar radiocarpal ligament
rc joint contributes more to blank than mc joint
flexion
mc joint contributes more to blank than rc joint
extension
rc joint is blank carpals moving on blank radius
convex, concave
flexion of rc joint is a palmar roll and blank glide
dorsal
extension of rc joint is a blank roll and palmar glide
dorsal
radial dev of rc joint is blank roll and blank glide
radial, ulnar
ulnar deviation is blank roll and blank glide
ulnar, radial
with flexion, the blank flexes, the blank and blank extend…. this is called blank which increases ligament tension and stability
scaphoid, lunate/triquetrum, counter rotation,
coming together of carpal articular surfaces increases blank
stability
extension causes scaphoid to blank, while blank and blank flex
extend, lunate, triquetrum
two halves of the blank joint
mc (midcarpal)
2 halves of mc joint
radial, ulnar
ulnar side of mc joint is blank hamate and capitate moving on blank lunate and triquetrum in frontal and sagittal planes
convex, concave
radial side of mc joint is blank trapezoid and trapezium moving on blank scaphoid in frontal and sagittal planes
concave, convex
blank deviation helps stability of rc and mc because they will be blank
radial, close packed
ulnar side of mc and the whole rc are linked blank
anatomically/functionally (vex on cave)
radial side of mc and the whole rc are linked blank
anatomically (cave on vex)
secondary wrist action is from muscles that cause movement at blank primarily
digits
origins/insertions pictures are well shown on the ppoint for lecture
ok
ecrb attaches at the 3rd digit at the base so its only job is to blank
exten
if ed was compensating for weak ecr, we would also get blank rather than just wrist extension
finger extension
adm originates at blank
pisiform
fcu contraction stabilizes blank to allow abduction of blank digit
pisiform, 5th
adaptive shortening in a quadraplegic allows for better blank
function
where adaptive shortening is good for function
tenodesis
example of tenodesis function
grabbing a cup
fcu and ecu allows pure ulnar deviation are blank
equal to each other
