Hand Flashcards
what do you call the tips of the fingers?
pulp
describe the arthrokinematics of the fingers
open chain concave on convex
describe the orientation of the first MC
medially rotated 90 degrees
what are the three palmar arches?
- proximal transverse
- distal transverse
- longitudinal
what do the palmar arches do? generally
maximize contact with the objects we grasp for dexterity and sensory
what is the proximal transverse arch?
distal row of carpals
what is the keystone of the proximal transverse arch?
capitate
what does the proximal transverse arch do?
forms a rigid arch and the carpal tunnel
what is the distal transverse arch?
MCP joints
what is the keystone of the distal transverse arch?
MCP joints
what does the distal transverse arch do?
mobile arch for hand flexibility
what is the longitudinal arch?
the 2nd and 3rd rays
what is the keystone of the longitudinal arch?
2nd and 3rd MCP joints
is the longitudinal arch stable or mobile?
both: stable proximally (CMC) mobile distally (phalanges)
what is the “central pillar” of cmc joint mobility?
CMC 2 and 3
describe CMC joint mobility (3)
- 2 and 3 very stable
- 2 and 4 have one degree of freedom
- 1 and 5 have two degrees of freedom
what permits a cupping shape of your hand?
greater ulnar mobility at CMC
describe pistol grip
broader grip around the pinky area to avoid active insufficiency of ulnar side finger flexors
Which 1st CMC motions are convex on concave? concave on convex?
- vex on cave
- abd/add
- cave on vex
- flx/ext
- ***flx/ext is similar to how our fingers work!***
what are the 2.5 component motions of thumb opposition?
- abduction
- flexion/medial rotation
what increases MCP joint congruence?
volar/palmar plate
what is the MCP closed pack position?
flexed
what are MCP flexion and extension ROM?
flexion 90, extension 45
what are PIP and DIP ROM
PIP 100, DIP 90
what are the two major features of the flexor mechanism?
- bursae reduce friction
- annular ligs maintain tendons from bowstringing
what happends if the flexor tendons bowstring?
reduced flexion ROM
what needs to happen for isolated PIP flexion?
extensor stabilization
what are the three primary finger extensors?
ED, EI, EDM
what hand deformities result from loss of intrinsic muscle function?
claw hand and intrinsic minus hand
how do intrinsics aid finger extension?
they stabilize the MCP and extend the PIP and DIP through the extensor hood
what is the intrinsic plus position?
lumbricals and interossei co-contracting - lego hand
