Hand and Wrist Flashcards
how many intrinsic and extrinsic muscles of the hand
19 intrinsic
20 extrinsic
main function of the wrist
fine tune position of the hand
three main roles of the hand
expression and communication
protection
sensory
how many bones of the whole wrist hand complex and what are the main groups
radius/ulna
carpals
metacarpals
phalanges
three parts of the distal ulna
ulnar styloid process
fovea - attachment for the disc
pole
what is the function of the pole of the ulna
articular surface for the TFCC
three main features of the distal radius
distal surface
radial styloid process
ulnar notch
what is landmark of the radius where it interacts with the ulna
ulnar notch
function and location of listers tubercle
dorsal distal aspect of the radius
it is a pulley, redirect action of extensor digitorum longus and extensor indices on radial side
redirects action of extensor policies longus on the ulnar side
name the bones of the hand
scaphoid lunate triquetium pisiform trapezium trapezoid capitate hamate
shape of pisiform and what inserts here
sesamoid, flexor carpi ulnaris
what is unique about the capitate
central position of the hand, axis of the hand
how many phalanges for each of the digits
thumb: two
digits 2-5: three
shape of base of phalanges
biconcave, smaller articular surface than head
shape of heads of phalanges
bicondylar
how many bones and joints in the wrist complex
15 bones
1`7 synovial joints
movements and type of joint: distal radioulnar
uniaxial pivot joint
pronate/supinate
three structures that connect the distal radioulnar joint
TFCC, obliques fibres of the distal interosseous membrane, radioulnar ligaments
movements and type of joint: radiocarpal
ellipsoid synovial, 2 DOF
flex/ex, radial and ulnar deviation
what is articulating with what at the radio carpal joint
distal radius with scaphoid and lunate
what the TFCC articulate with at the radoiocarpal joint
ulnar stylus and triquetrium
what types of joint are the mid carpal joints and what movements do they do (compound articulation, two parts to to this)
synovial plane joints
Planar laterally: scaphoid, trapezium, trapezoid
Condylar medially: scaphoid, lunate, triquetrium, capitate and hamate
general flex/ex, ulnar/radial deviation
what type of joint is intercarpal and what it is between
joint between bones of proximal and distal rows
plane synolvia joints, allowing for gliding movements
what is the arch in teh hand formed by (general structures)
carpals, metacarpals, and ligaments
carpometacarpal joints 2 to 5
- which have the movement movement (how much)
- which have the least movement
minimal at 2nd and less at third
4th = 10-15 degress
5 = 25-35 degrees
function of movements at the carpometacarpal joints 4 and 5
allow transition of the hand from flat to fist
1st carpometacarpal: type of joint, between what bones
synovial saddle
between base of 1st MC and trapezium
movements of teh 1st CMC
flex, ex, abduction, adduction, opposition, repositioning
metacarpalphalangeal joints: type, movements
synovial condyloid with 2 DOF (flex, ex, ad, ab)
what are the head of the metacarpals covered with
articular cartilage
what are the bases of the metacarpals extended with with
fibrocartilaginous volar plates
interphalangeal joints: type, movements
synovial hinge, flex/ex
what two structures to DIPs and PIPs have that help them move as well and reinforce them
volar plates, check rein ligaments
what is volar plate
- structure
- attaches to?
- motion through joint motion
- function
- prevents
thin capsule proximally and thick capsule distally
attaches to distal phalanx and collateral ligaments
as joint flexes, volar plate slides proximally UNDER MC with a folding of its membrane
allows for large ROM over small surface area
prevents hyperextension and Doral subluxation
distal radioulnar ligaments = O, I, A
O: ulnar notch of radius
I: ulnar styloid process and ulnar fovea
A: part of the TFCC that stabilizes the distal radioulnar joint
radial collaateral ligament:
O, I, function
O: radial styloid process
I: scaphoid and lunate
Function: restrict ulnar deviation, lateral stabilization of the radial wrist
ulnar collateral ligament: O, I, Function
O: ulnar styloid process
I: pisiform and triquetrum
Function: restrict radial deviation, lateral stabilization of ulnar wrist
Radoiocarpal ligaments - palmar: O, I, function
O: anteroinferior radius, radial styloid process, palmar anteromedial ulna
I: palmar surface of scaphoid, lunate, capitate, triquetrum
A: volubly stabilize radius to carpals, limit excessive wrist extension
Radoiocarpal ligaments - dorsal: O, I, function
O: posterioinferio radius
I: dorsal surface of scaphoid, lunate and triquetrum
A: dorsally stabilize radius to carpal, limits excessvie wrist flexion
What is the TFCC made of
complex composed of articular disc, menisci homologue, ulnocarpal ligaments, dorsal and volar distal radioulnar ligaments, sheath of extensor carpi ulnaris and prestyloid recess
where des TCFF insert
distally into triquetrum, hamate and base of 5th metacarpal
functions of TFCC
load absorption and transmission
stabilize distal radioulnar joint
axial loading of wrist is split into what percent onto radius and ulna
82% radius, 18% ulna
where do ulna carpal ligaments originate
from the fovea
how much does pronation increase ulnar variance
1mm
how much does grip increase island variance
4mm
what is the flexor retinaculum
- attachments
- function
- point of origin for what
“carpal tunnel”
- attached to triquetrum, pisiform, hook of hamate, tubers of trapezium and scaphoid
- create passage for tendon of flexor pollicus longs, flexor digitorum superficial and profundus and median nerve
- point of origin for thenar eminence
what is teh extensor retinaculum
- what does it restrict
- what reduces friction
thickening of dorsal forearm fascia
subdivided into compartments
restricts tendon bowstring during wrist hyperextension
tendon wrapped in synovial sheath to reduce friction
medial and lateral collateral of the fingers: O, I, function in flexion and extension
O: head of metacarpal phalanx
I: base of neighbouring phalange
Flex: tight, assist with grip
Ex: loose: allow ab/ad at MCP
deep metacarpal transfer ligament: attachments, function
attaches for metacarpal head 2-5, volar plates
allows for flexible metacarpal arch
what muscles on ulnar and radial side of thumb attach to volar plate and control thumb
Ulnar: adductor polices and first dorsal interossi tendon
Radial: flexor policies Brevis and abductor Brevis
what is the shape of teh structure that facilitates pinching precision
sesamoid
when elbow flexed greater than 15 degrees, how does the line fo pul and action of elbow wrist extensors changes, what muscle is best at this
anterior elbow axis transitions and wrist extensors can become elbow flexors
extensor carpi radialis longus can be and effective elbow flexor
wrist flexors originate where
medial epicondyle of elbow
name the primary wrist flexors
flexor carpi radialis flexor carpi ulnaris flexor digitorum superficualis flexor digitorum profundus palmaris longus flexor pollicis longus abductor pollicis longus
can wrist flexors acts at elbow extensors? how so compared to wrist extensors?
they can if elbow is flexed, not as powerful s wrist extensors though
what muscle interactions causes ulnar and radial deviation
extensors and flexors work synergistically
ECU, FCU together!
ones further from centre axis help more
main function of extrinsic muscles of finger
strength and gross motor control
which muscle extends all teh fingers
extensor digitorum
flexor digitorum superficialis: how does this muscle split and where do the split ends insert
split into two, which each split into two tendons
2 superficial tendons go to digits 3 and 4
2 deeps tendons go to digits 2 and 5
location of flexor digitorum profundus, what does it go under
anterior ulnar side of forearm
goes unser FDS and splits into four tendons
four main thumb extrinsic muscles and function
flexor pollicus longus - primary thumb flexor, only IP flexor extensor pollicus longus and Brevis - extension synergists abductor pollicius longus - main thumb abductor
function of intrinsic hand muscles
fine motor movements
what is the group name of the thumb intrinsic muscles
thenar muscles
what is the group name of the pinky pinger muscles
hypothenar
function of the Interossei muscles
adduct fingers
function of lumbricals
flex MCP and extend IP
what is the function extensor hood and flexor tendon sheath
structure of the fingers and thumb designed to
- hold flexor and extensor tendons in place
- allow them to move and glide
- guide direction of pull
what is the extensor mechanism of the fingers made up of
intrinsic muscles
long finger extensors
long finger flexors
mechanism made up of distal tendinous attachments, retinacula and ligaments
what is the purpose fo the extensor mechanism
allow extension of digits in multiple finger positions and permit full flexions
what is trigger finger
dysfunction of the flexor pulley module or thickened tendon sheath glide through pulley interrupted
flexion is made up of how much movement at radoiocarpal and how much at mid carpal joint
50 degrees at radoiocarpal and 35 degrees at mid carpal joint
extension is made up of how much movement at radoiocarpal and how much at mid carpal joint
50 degrees at midcarap, 35 degrees and radoiocarpal
axis for flex ex of the wrist is
capitate
closed position for the wrist
full wrist extension
how much flexion at MCP joints
90 degrees
closed packed position of MCPS
full flexion
up to how many degrees extension at MCPs
45 degrees
how much ad and ab at MCP when MCPs are extended
how much when flexed
20 degrees when extended for both
almost none when flexed
how much flex and ex for thumb
flex = 45-60 ex = 0-20
how much flex at ex at IP joints
120 flex
0 ex
closed packed position of Thumb
full extension
closed packed position of MCP and IP 2-5
full flexion
what are power grips of the hand
incorporate the entire hand
used for grasping activities
involved in holding an object between partially flexed fingers and palm while thumb provides pressure
what are the four power grips of the hand
fist, cylindrical, hook, spherical
what are precision grips
used for accuracy and refinement, object manipulation
thumb abducted, ready to oppose
types of precision grips
tip to tip pinch
lateral key pinch
three prong Chuck
grip strengt males vs females and dominant vs non dominant
males average 2x greater than females of similar age
6% stronger on dominant side
what wrist position decreases grip strength
wrist flexion
optimal wrist position for grasping
20-35 degrees extension with slight ulnar deviation
what is mallet finger
trauma to DIP
generally caused by an impact force to the fingertip
avulsion of the lateral bands of the extensor tendon
permanent flexion of teh DIP
what is boutinneir deformity
central slip of extensor digitorum at middle phalanx
flexed position of PIP results in lateral band being place posterior to teh axis of motion for the DIP causing hyperextension
what is swan neck deformity
primarily associated with arthritis
weakened fo teh hand intrinsics resulting in the PIPS hyperextending
causes lateral slop of the extensor tendon to shift dorsally relative to the joint
what is Dupuytren’s contracture
palmar fascia is thickened with fibrosis
primarily at digits 3 and 4
pits and modules, tendon not directly involved
what is Volkmanns contracture
ischemic flexion deformity
from ischemic necrosis of the forearm flexors
pressure injury with forearm compartment
muscles replaced by contracted fibrous tissue
radial nerve injury causes
effects extensors
wrist drop - effective grasp not possible
median nerve injury causes
innervate most flexors (not FCU)
hand of benediction
ape hand (inability to oppose)
ulnar nerve injury causes
supplies most small muscle of the hand except FDP/lumbrical split/thenars
ulnar claw
- injure can occur at forearm or wrist
fourth and fifth digits mostly affected
