Wrist and Hand Flashcards
where is the thenar eminence located?
thumb side (radial side)
where is the hypothenar eminence located?
pinky side (ulnar side)
what do the hypothenar and thenar eminences contribute to?
better grasp
how are the palmar flexion creases formed?
by the amount of movement you do
what is the CMC joint?
carpometacarpal joint
carpal bone to base of metacarpal bone
what is the MCP joint?
metacarpophalangeal joint
head of metacarpal to base of proximal phalanx
what is the PIP joint?
proximal interphalangeal joint
head of proximal phalanx to base of middle phalanx
what is the DIP joint?
distal interphalangeal joint
head of middle phalanx to base of distal phalanx
where are the peripheral joints?
first, fourth, and fifth metacarpals
where are the central joints?
second and third metacarpals
what is the most important aspect of active grasp?
the mobility of the CMC joint
what kind of shape do the carpal bones/palmer surface of the hand make, and what is it good for?
bowl shaped (concavity)
good for grip
is there as much movement at the CMC joints of the second and third metacarpal as there is at the first, fourth, and fifth?
no, the peripheral joints provide more movement
what type of joint is the CMC joint of the thumb?
a sellar/saddle joint
what makes a joint a sellar/saddle joint?
there ALWAYS has to be a third movement involved
in terms of the thumb, it’s flex/ext, abd/add, AND opposition
what does having the ability to oppose differentiate for us?
separates us from other species
where are the two axis of the CMC joint of the thumb?
frontal axis through the tripezium
sagittal axis through the base of the first metacarpal
what shape is the MCP joint?
condylar shape – concave on top of convex
when in FLEXION, are the collateral ligaments taut or looser?
taut
when in EXTENSION, are the collateral ligaments taut or looser?
looser
what is another term for the palmar ligaments?
the palmar plates
what is the palmar ligament made up of?
fibrocartilaginous pads
what do the palmar ligaments/plates do?
holds the tendons in place for active grasp
what do the deep transverse ligaments do?
connects the metacarpal heads
the extensor hoods of the fingers are also known as what?
expansion hoods
where are the extensor hoods located?
at the CMC joint
what do the extensor hoods become?
expansion of the extensor digitorum tendon becomes a ligamental/connective tissue structure that anchors the tendon on to the bony structure of the finger
what do the extensor hoods do?
protects the dorsal surface of the joints, then creates a fulcrum point, which gives that tendon the ability to release
what type of joints are the PIP and DIP joints?
hinge joitns
what action do the PIP and DIP joints provide?
flexion and extension
what is the other name for the palmar plates (yes, there’s a third name)
volar plates
what do the palmar plates do?
protects the joint on the palmar surface and prevents hyperextension
what is important to know about the palmaris longus?
it is not present in everyone/most, some people could also only have it on one side
what does the palmar aponeurosis do?
connects to the distal edge of the flexor retinaculum and provides an insertion point for some flexor muscles
what is Dupuytren’s?
it is a type of flexion contracture, especially at the MCP joint.
what is the fibrous digital sheath?
ligamentous tissue that enclose synovial sheaths and tendons of the digits
what does the fibrous digital sheath do?
provides strength and integrity at the joints
what is the orientation of the fibers of the fibrous digital sheath?
cross hatch
what is the benefit of the orientation of the fibrous digital sheath?
provides more strength/stability for holding tendons over the JOINT
ONLY HERE TO provide more strength
where is the radial bursa located?
flexor pollicis longus
where is the ulna bursa located?
flexor digitorum superficialis and flexor digitorum profundus
what do the digital synovial tendon sheaths do?
lubricates and secretes synovial fluid onto the tendon to allow ease of movement
what can cause trigger finger?
swelling of the synovial sheaths, which can pull the tendons of the fingers down and create trigger finger
what are the only two tendons that create active grasp in a flexed position?
flexor digitorum superficialis and flexor digitorum profundus
what is the role of the “lizard’s tongue” ending of the flexor digitorum superficialis?
allows passageway of the FDP tendon to attach to the distal phalanx
what holds the extensor tendon sheaths together?
the extensor retinaculum
what does the median nerve run under?
the palmaris longus, THRU carpal tunnel
what is median nerve palsy also known as?
Pope’s Blessing*
Ape Hand
what is median nerve palsy?
loss of the thenar muscles, results in the loss of opposition in the thumb
where does the ulnar run ABOVE?
above the flexor retinaculum
what is ulnar nerve palsy also known as?
Claw Hand
what is ulnar nerve palsy?
loss of flexing action at the MCP joints
what is radial nerve palsy also known as?
Wrist drop
what is radial nerve palsy?
loss of all muscles capable of producing extension of the wrist DUE TO A COMPLETE LESION/SEVERING OF THE RADIAL NERVE
What is ulnar nerve entrapment?
A painful disorder of the lower arm and wrist caused by compression of the ulnar nerve at the wrist in Guyon’s canal or in the cubital tunnel
