Wrist and Hand Flashcards
(153 cards)
list the carpal bones in the proximal row (M-L)
pisiform, triquetrum, lunate, scaphoid
list the carpal bones in the distal row (M-L)
hamate, capitate, trapezoid, trapezium
how many degrees of freedom are at the humeroulnar articulation?
1
why is there only 1 df at the humeroulnar joint?
so that muscles that originate on the distal humerus have more stability to allow for distal mobility
what is the main weight bearing joint fixed in closed chain of the wrist and hand?
the radiocarpal joint
what type of relationship do the “working end” of levers have?
inverse relationship
the radius expansion at carpus is primarily for?
weight bearing
the ulna expansion at the humerus is primarily for?
site of muscle attachment
the ulna expansion at carpus is modified for radius and hand to rotate creating a space called…
ulnocarpal space with triangular fibrocartilage
what is the central column/pillar effect?
think of a bridge the center is the most stable and keep the bridge standing without it it would fall. In the hand think of the lunate and capitate so CMC 3 is most stable
what drives motion in the hand around central column?
thenar and hypothenar
what two planes does biaxial motion occur in?
frontal and saggital
what plane does flexion and extension of the wrist occur in?
saggital plane about an M-L axis
what is the normal range for wrist flexion?
80-90º
what is the normal range for wrist extension?
70-80º
what plane does radial and ulnar deviation occur in?
frontal plane about an A-P axis
what is the normal range for radial deviation?
20-25º
what is the normal range for ulnar deviation?
30-35º
what is something that is a restricter to radial deviation?
radial styloid
what articulates proximally at the radiocarpal joint?
radius and radioulnar disk/TF
what articulates distally at the radiocarpal joint?
scaphoid, lunate and triquetrum
what carpal bone articulates with the lateral radial facet of the radiocarpal joint?
scaphoid
what carpal bone articulates with the medial radial facet of the radiocarpal joint?
lunate
what carpal bone articulates with the inferior radial facet of the radiocarpal joint?
triquetrum