last minute hand exam Flashcards
(26 cards)
what muscles are in the pulleys (there are 5 pulleys starting at the base of the metacarpal head)
FDS which stops after PIP
FDP which goes to the DIP
the sagittal band goes around what structures
the volar plates to stabilize them over the metacarpal heads
Connects the volar plate to the extensor digitorum communis tendon and extensor expansion
What does the volar plate do?
reinforces the IP joint capsule, improves stability and limits hyperextension
interphalangeal ligaments (collateral ligament proper, accessory collateral ligament) both provide stability MCP and IP joints during AROM as as with _______
varus and valgus stress
the collateral ligament proper gets taut with
MCP flexion
Accessory collateral ligament becomes more taut with MCP ______
extension
IP joints
synovial hinge joint, 1 degree of freedom, flexion extension and VOLAR plates reinforce IP capsules
metacarpophalangeal (MCP) joints
2 degrees of freedom
flexion and extension
abduction and adduction
joint reinforced by the deep transverse metacarpal ligament
palmar arches, 3 of them
proximal transverse arch, at carpals
distal transverse arch, at the MCP
longitudinal arch, making the C
the opponens digiti minim (ODM) is the only muscle to exclusively impact movement of a
CMC joint
the opponens digiti minimi
only muscle to exclusively impact movement of a CMC joint
to flex and rotate the 5th metacarpal along its long axis
only muscle to act on finger CMC joint, the opponens digiti minimi
Deep transverse metacarpal ligament
spans between 2nd and 4th metacarpal heads
contributes to CMC stability and limits abduction
blends with the anterior joint capsule of each digit
it prevents entrapment of the FDP with MCP flexion and maintains the interossei in a position dorsal to the ligament
one of the most common pathologies of the hand, affects TRAPEZIUM and 1st metacarpal due to degenerative changes, pain is elicited with prehension, common elective surgery of the hand
CMC arthritis
primary function of thumb is
opposition = abduction followed by flexion followed by adduction
provides almost all forms of prehension
thumb
FDS
produces most torque at the MCP joint than the FDP
FDP
can flex all 3 joints of the fingers?
Dorsal interossi (DAB)
abducts around 3rd digit
Palmar interossei (PAD)
ADDucts around the 3rd digit
intrinsic finger mm - flexor pollicis brevis
palmar interossei - from carpals to proximal phalanx of 1st digit
intrinsic finger mm - abductor digital minimi (ADM)
dorsal interossei - carpals to proximal phalanx of 5th digit
extensor mechanism
triangular ligament, oblique retinacular ligament, sagittal bands
All help to prevent bowstringing during extension of MCP
Also formed by a bunch small extensor tendons
extensor mechanism influence on MCP and IP function
extensor digitorum communis contracts
tension on sagittal bands
proximal phalanx rolls/glides dorsally on metacarpal
interossei, dorsal, volar, lumbricals do IP extension
functional position of the hand
wrist - slight extension, slight ulnar deviation
MCP and PIP - moderate flexion
DIP - slight flexion
