hand Flashcards
what are the main types of grip *
power grip
precision grip
hook grip
describe power grip *
the fingers are flexed around the object with opposing power from the thumb eg grasping a rod
muscles involved in the power grip *
long flexors of the finger and thumb
the intrinsic muscles of the palm
the extensors of the wrist joint - to give more power to the long flexors (posterior hand muscles are involved)
describe the precision grip *
the object is gripped between the tips of the fingers and the thumb
eg unbuttoning a shirt
muscles involved in the precision grip *
teh wrist and fingers are held rigidly by the long flexors and extensors
the intrinsic muscles of the hand carry out the dine movements needed
forearm control of the wrist - dont wnat the wrist to get floppy
describe the hook grip *
consumes little energy
eg carrying shopping bag
muscles involved in the hook grip *
mainly involves long flexors of the digits
summarise teh facia of the palm *
it is anatomically continuous with the fascia of the forearm
the palmar fascia is the fascia of hand that lies in the palm - dense
there are specialisations (condensations) of the palmar fascia that form the palmar aporneurosis and the fibrous digital sheaths
describe the palmar aporneurosis *
it overlies the long flexor tendons of the hand
the proximal end is continuous with the flexor retinaculum and the palmaris longus tendon
the distal end of the aporneurosis is continuous with teh fibrous digital sheaths
describe the fibrous digital sheaths *
they contain the flexor tendons and their synovial sheaths which wrap round the tendons and bones
describe the extensions of fascia called septa *
they extend from teh palmar aporneurosis to the boens of the hand - separating the space between the aporneurosis and bones into compartments
separate vessels and muscles and tendons running from wrist
a medial septum goes to the little finger metacarpal
a lateral septum goes to the middle finger metacarpal
these septi divide the space into a
- hypothenar compartment
- central compartment
- thenar compartment
- adductor compartment
deep to the thenar compartment is the adductor compartment which contains the adductor pollicus muscle
what are the bones of the wrist and hand *
the radius
ulnar
carpus (carpal bones)
- proximal row: sphenoid, lunate, triquetrum, pisiform
- distal row: trapexium, trapezoid, capitate, hamate
the metacarpal bones
the phalanges
what muscular compartments are involved in the hand region *
anterior compartment of the forearm - superficial and deep
posterior compartment of the forearm
posterior compartment of the forearm
intrinsic muscles of the hand
- thenar compartment muscles
- adductor comaprtment
- hypothenar compartment
- interossei and lumbricals
what are the muscles of the superficial anterior compartment of the forearm *
pronator teres
flexor carpi radialis
palmaris longis
flexor carpi ulnaris
flexor digitorum superficialis
what are the muscles of the deep anterior compartment of teh forearm *
flexor digitorum profundis
flexor pollicus longus
pronator quadratus
what are the muscles of the extensor compartment of the forearm *
muscles that move the wrist joint
- Extensor carpi radialis longus (ECRL)
- Extensor carpi radialis brevis (ECRB)
- Extensor carpi ulnaris (ECU)
muscles that move the digits
- Extensor digitorum (ED)
- Extensor indicis (EI)
- Extensor digit minimi (EDM)
muscles that move the the thumb
- Abductor pollicis longus (APL)
- Extensor pollicis brevis (EPB)
- Extensor pollicis longus (EPL)
other muscles
- Brachioradialis
- Supinator
what are the intrinsic muscles of the hand *
thenar muscles
- abductor pollicus brevis
- flexor pollicus brevis
- opponens pollicus
adductor muscle - single muscle
- adductor pollicus
hypothenar muscle
- abductor digiti minimi
- flexor digiti minimi
- opponens digiti minimi
interossei and lumbricals
- lumbricals
- palmer interossei (3)
- dorsal interossei (4)
other
- palmaris brevis
functions of the interossei and lumbricals *
lumbricals - flex the MCJ’s, extend the IPJ’s
palmar interossei - adduct the digits (PAD)
dorsal interossei - abduct the digits (DAB)
describe the anterior tendinous anatomy of teh hand *
teh fibrous digital sheaths extend from the level of teh metacarpal head to the base of teh distal phalanx in each digit
with the underlying bone the sheaths form the osseo-fibrous tunnels
the long flexor tendons and their synovial sheaths run in these tunnels
part of the digital sheaths form condensations called pulleys - allow for more function of the long flexor tendons
these are the annular and cruciform pulleys
after passing the wrist joint the flexor digitorum profundus and flexor digitorum superficialis pass in the carpal tunnel beneath the flexor retinaculum and enter a common tendinous sheath
the tendons pass to their respective digits in a digital synovial sheath (sheath is wrapped around the tendon forming a double layer, rather tahn the tendon being in the sheath), which is in its own fibrous digital sheath (synovial sheath prevents friction)
the digital synovial sheaths of the index, middle and ring fingers are separate from the common synovial sheath, those of the little finger and thumb are continuous with the common sheath
at the proximal base of the phalanx - the tendon of teh FDS splits around the FDP
the FDS attaches to the anterior surface of the middle phalanx and teh FDP attaches to the distal phalanx (FDS doesnt go as far)
the tendon of the flexor pollicus longus has its own synovial sheath at the flexor retinaculum - this runs to the distal phalanx of the thumb
describe the posterior tendinous anatomy of the hand *
all the extensor tendons are held to the dorsum of the wrist by the extensor retinaculum (not as tough as the flexor retinaculum)
there are synovial tendon sheaths that surround the tendons fascilitating free movement of the tendons - some sheaths are connected some are individual
the long extensor tendons to the digits are joined by intertendinous bands - they prevent free movement of 1 extensor tendon independantly of the others
at the metacarpals the long extensor tendons flatten to form extensor expansions - they form a hood on the back of the digit. they are intrically involved in the movement of the digits
the lumbrcals and interossei attach to the expansions
the extensor digitorum extends the metacarpo-pharyngeal joint and the interphalangeal joint. it extends the wrist joint after maximal extension of the digits
what are the joints in the hand *
distal radio-ulnar joint
wrist joint
intercarpal joint
carpo-metacarpal and inter-metacarpal joints
metacarpo-phalangeal joints
interphalangeal joints
what movements do the midcarpal (joint between prox and distal carpal row) and carpo-metacarpal joints allow *
flexion and extension
what are the series of intercarpal joints *
joints between the prox row
joints between the distal row
joints between the prox and distal row - midcarpal joint
what type of joint are the intercarpal joints and what is the movement *
plane synovial
gliding - augmenting the flexion and radial deviation of the wrist joint
describe the carpometacarpal joints *
the CMC joint of thumb is between the trapezium and the thumb metacarpal - synovial joint of saddle variety allows thuim to move in different direction
CMC of digits are between trapezoid, capitate, hamate and metacarpals - they are synovial elipsoid
CMC of index and middle finger is rigid
CMC of ring finger is less
CMC of little is very mobile
clinical importance of the carpometacarpal joint of the thumb *
becomes osteoarthritic
describe the intermetacarpal joints *
plane synovial joints
between the metacarpals at their bases
describe the movements at the carpometacarpal and intermtacarpal joints *
flexion and extension
radial deviation and ulnar deviationn
circumduction
describe the metacarpophalangeal joints *
condylar synovial joints between metacarpal heads and prox phalanges
what movements do the metacarpophalangeal joints allow *
flexion and extension
abduction and adduction
together - circumduction
describe the interphalangeal joints*
hinge synovial joints
there is a proximal IP and distal IP joint
in thumb only 1 IP joint
movements of the interphalangeal joints *
flexion and extension only
describe the ligaments holding teh metacarpophalangeal and interphalangeal joints together *
they include collateral ligaments both ulnar and radial
ulnar collataral ligament of thumb is frequently injured skiing
connection between phalanxes is not very strong - not good fit between bone therefore ligaments hold bone in place but only allow flexion and extensioon of IPJ
what is the volar plate *
it is on the anterior surface of the prox IP joint
it is a dense condensation of fibrous tissue formed by collateral ligaments
frequently damaged
what are the muscles that move the thumb *
abduction
- abductor pollicus longus
- abductor pollicus brevis
adduction
- adductor pollicus
- first doral interosseous
extension
- extensor pollicus longus
- extensor pollicus brevis
- abductor pollicus longus
flexion
- flexor pollicus longus
- flexor pollicus brevis
opposition
- opponens pollicus (works at carpo-metacarpal joint)
- occurs at the metacarpo-phalangeal joint and involves abduction, flexion, and adduction at the metacarpo-phalangeal joint
describe the arterial supply of the hand *
hand supplied by the radial and ulnar arteries
in the hand there are extensive anastomoses between the ulnar and radial arteries
ulnar artery runs in anterior comp of forearm - passes on ulnar side of palmar surface of wrist. artery is lateral to ulnar nerve which is lateral to flexor carpi ulnaris. the artery supplies medial muscles of the forearm - branches into the common then posterior and anterior interosseous artery. enter hand passing over the flexor retinaculum lateral to pisiform through semi-rigid ulnar (Guyon’s) canal with teh ulnar nerve. It divides just below this into
- superficial palmar arch (recieves branch from superficial palmar branch of radial artery)
- gives off 3 common palmar digital arteries - they divide into palmar digital arteries
- the deep palmar branch of ulnar artery
radial artery passes down lateral aspect of forearm under brachioradialis muscle and beside FCR at wrist. it crosses floor of anatomical snuff box and enters palm of hand between the 2 heads of the 1st dorsal interosseous muscle, then passes between the 2 heads of the adductor pollicus muscle. it anastomoses with deep palmar branch of ulnar artery to form deep palmar arch
deep palmar arch gives origin to palmar metacarpal arteries
arteries also form dorsal carpal arch
where is the radial artery palpable
at the wrist
lies superficially on palmar aspect of radial side of wrist
describe the venous drainge of the hand *
deep and superficial arterial arches have corresponding palmar venous arches - deep drainage
dorsal digital veins drain into dorsal venous arch (superficial system) on dorsum of hand
arch gives rise to cephalic and basilic vein laterally and medially
most drainage is through the superficial system
what are the 3 main nerves to the hand *
median nerve c6-t1
ulnar nerve c8-t1
radial nerve c5-t1
what nerves contribute to sensory supply of the hand *
ulnar
median
radial
they do so in the digits through digital nerves
effect of division of one of the digital nerves
anaesthesia in part of the digit
describe the path of the median nerve *
supply anterior compartment of the hand and forearm
descends through anterior comp of arm - no branches
in cubital fossa it lies medial to brachial artery (can be damaged by supracondylar fractures of humerus or dislocations)
passes between the heads of the pronator teres
at wrist lies superficially between the tendons of FDS and FDP and deep to palmaris longus
enters the carpel tunnel - here it is accompanied by 9 flexor tendons (FDP FDS FPL)
passes under the flexor retinaculum
the recurrent branch of median nerve leaves main trunk in carpel tunnel and supplies the 3 thenar muscles
what does the median nerve supply*
in forearm
- pronator teres
- FDS
- lateral protion of FDP
- FCR
- pronator quadratus
- palmaris longus
after passing under the flexor retinaculum
- the 3 thenar muscles - abductor pollicus brevis, flexor pollicus brevis and opponens pollicus
- the lateral (2 and 3) lumbricals
sensory
- palmar surface of thumb
- index and middle finger
- lateral half of ring finger
- some dorsal supply
(main nerve to the anterior compartment of the forearm, some supply to intrinsic hand muscles)
describe the path of the ulnar nerve *
initially descends in the anterior compartment of the arm
more distally enters the posterior comp - lies superficially posterior to medial epicondyle
no branches in arm
enters anterior comp of forearm between heads of flexor carpi ulnaris and descends on medial side of forearm
proximal to wrist it gives off 2 branches - palmar cutaneous branch, dorsal cutaneous branch
at wrist lies anteriorly - between FCU (medially) and ulnar artery (laterally) then passes into hand
passes over the flexor retinaculum in ulnar canal with ulnar artery, lateral to the pisiform bone
it divides distal to the flexor retinaculum to superfical and deep braches
what does the ulnar nerve supply *
in forearm
- FCU
- medial portion of FDP
palmar cutaneous branch supplies medial palm of hand
dorsal cutaneous branch supplies medial half of dorsum of hand, including little and ring fingers
superficial branch of ulnar nerve - sensory to palmar surface of little finger and medial sode of ring finger
deep branch of ulnar nerve - motor to
- hypothenar muscles (abductor digiti minimi, flexor digiti minimi, and opponens digiti minimi)
- abductor pollicis
- the medial (fourth and fifth) lumbricals
- all interossei
it controls most of muscles involved in fine movements of the hands
describe the path of the radial nerve *
lies on the humerus in the radial groove
superior to elbow divides into superficial radial nerve (sensory) and deep radial nerve (motor)
superficial branch is cutaneous - sensory to lateral 2/3 of dorsum of hand, dorsum of thumb and proximal portions of dorsal of index and middle fingers
posterior interosseous nerve is continuation of deep radial nerve as it passes between heads of the supinator
supplies all extensor parts of forearm and arm
doesnt supply any muscles in hand
what does the carpal tunnel contain *
median nerve
FPL tendon
4 tendons of FDP
4 tendons of FDS
what is the carpal tunnel made from *
base - bony arch of teh carpal bones
roof- flexor retinaculum (called transverse carpal ligament)
bony attachments - palpable
- scaphoid, trapezoid, (laterally)
- pisiform, hamate (medially)
what is carpal tunnel syndrome *
compression of the median nerve in the carpal tunnel
causes tingling, loss of sensation and pain in the hand
what are the names and numbers of digits, would you use names or numbers clinically
thumb
index finger
middle
ring
little
1->5
never numbers - dont want people to count in emergancy, have to do it quickly
what carpel bones articulate in wrist joint *
proximal row with forearm bones
pisiform not involved - it is a sesamoid bone
how are the carpal bones involved in forming the carpal tunnel *
there are prominences medially and laterally formed by hook of hamate, pisiform (that sits anterior to the triquetum) tubercule of scaphoid and tubercle of trapezium
the form the bony attachments for the flexor retinaculum
what is clinically significant about the compartments of the hand
way the infection might travel
describe the thenar and hypothenar eminences *
they are the prominant parts on the thumb and little finger side of the hand - made by the muscles
what does it mean if a muscle is called carpi
acts across the wrist but doesnt go into digits
what does it mean if muscle is called digitorum
acts on medial digits 2-5
how can anterior comnpartment forearm muscles act on teh hand *
they attach across elbow joints and go across wrist and to digits
what are the intrinsic muscles of the hand involved in *
precise movements - small movements
what are the movements of the thumb *
abduction
adduction
extension
flexion
opposition
what are the muscles involved in moving the thumb *
abduction
- APL
APB
adduction
- adductor pollicus
- 1st dorsal interosseous
extension
- EPL
EPB - APL
flexion
- FPL
FPB
opposition
- opponens pollicus
muscles in the thenar compartment *
opponens pollicis
abductor pollicus brevis
flexor pollicus brevis
muscles in the hypothenar compartment *
abductor digiti minimi
flexor brevis digiti minimi
opponens digitu minimi
what supplies the thenar muscles *
median nerve - except for the adductor pollicis
describe teh adductor pollicis *
broad attachment on the middle metacarple
fan shape - fibres converge and insert on prox phalanx of thumb
describe the location of the lumbricals *
tehy attach top the tendons of the flexor digitorum profundus
distal attachment - converge to form tendon round to anterior of digit
insterts into connective tissue taht forms hood over digit - this is the extensor expansion
descrieb the arrangement of the dorsal interossei *
prox attachment between bones
tendons attach towards axial line (ie middle fingers) for dorsal interossei
tendons attach away from axial line for palmar interossei
DAB - dorsal abduct
PAD - palmer adduct (pull digits to axial line)
describe the tendinous anatomy of the digits anteriorly *
have annular and cruciate parts
tough ligamentosu structures wrap around the tendons’ synovial sheath
there are thicked palmar ligaments (plates) at joints
they ligaments pull the digit close to the tendon, so that tendon is held to the bone
describe the tendinous anatomy of the digits posteriorly *
extensor expansion over MPJ to there is a tendinous hood over the proximal IPJ
FDS attaches to base of middle phalanx
FDP - go to deep phalanx piercing FPS
lumbrical pulls the extensor expansion - flex teh MPJ and straighten the IPJ
describe the digital nerves *
purely sensory - no muscles in digits
often damaged - can cause disability, if cant feel things cant function properly
what is the innervation of the intrinsic muscles of the hand *
median supplies the thenar and lateral 2 lumbricals
ulnar supplies all otehr intrinsic hand muscles
describe teh palmar cutaneous branch of the median nerve *
branches before teh carpal tunnel
gives sensation to the arm
illustarte the pattern of innervation to the palmer surface of teh hand &
ulnar - digital branch to little and 1/2 ring finger
illustrate the pattern of innervation of innervation in the posterior of the hand *
superficial branch of radial nerve supplies the lateral aspect of the dorsal of the hand - sensory
dorsal branch of ulnar supplies the medial aspect of the palm
illustrate teh areas of cutaneous innervation of the hand &
describe the extensor digitorum tendon*
tendon expands over MCP - making the extensor expansion
lumbricles attach to the extensor expansion
the tendon carries on distally and then narrows out again
it allows complete extension of the digits
what is guyon’s canal *
ulnar nerve passes through - not affected as often as the carpal tunnel
identify teh location of the thenar and hypothenar muscles and lumbricles *
-
identify on the metacarpals the body (shaft) base (proximally) and head (distally) *
identify in the phalanges the body (shaft) base (proximally) and head (distally) *
where does secondary ossification of the metacarpals develop
the growth centres of the 4 fingers is at their heads
growth centre of the thumb is at base
where does secondary ossification occur in the phalanges
teh centres are at the bases
surface mark the cephalic, basilic and cubital veins *
mark them if can see
if not, illustrate where they would be - make sure median cubital is going down laterally
to demonstrate superficial veins - apply pressure around middle of arm by encircling with hands = venous congestion and distention distal to the compression
identify and palpate head of ulnar
little finger side of wrist
identify ulnar and radial styloid process *
wither side of teh wrist
identify the prox (and middle if present) and distal wrist crease and what do they indicate *
prox/middle - marks radio-carpal joint line
distal wrist crease - prox extent of the flexor retinaculum
identify teh dorsal venous arch
on dorsal of hand
identify the long extensor tendons
extend the wrist against resistance
palpate thenar and hypothenar eminance
by thumb and little finger
identify prox, distal palmar skin creases adn radial longitudinal crease
distal - mark position of metacarpophalangeal joints
radial longitudinal - partly encircles the thenar eminence
identify the digital creases on the palmar surface of fingers - prox, middle and distal
palpate the pisiform, tubercle of scaphoid, hook of hamate, ridge of trapezium
pisiform - distal end of FCU tendon
scaphoid - fully extend the wrist and it is along the line of FCR
hook of hamate - palpate deep to hypothenar muscles, 1cm distal and lateral to the pisiform
trapezium - palpate deep to middle of root of thenar muscles, distal to scaphoid
identify head of metacarpals and palpate
knuckes
identify radial styloid
in anatomical snuff box
identify scaphoid
in anatomical snuff box
identify the tubercle of teh base of the thumb metacarpal
in the snuff box
identify head of ulnar on dorsum of wrist
flex wrist to see
identify dorsal radial tubercle
EPL tendon of extended thumb leads towards the tubercle
identify the superficial palmar arch and deep palmar arch `
superficial - main artery is ulnar, distal limit of teh arch is at the level of the distal border of teh fully extened thumb just prox to prox palmar crease
deep - main artery is radial, teh arch lies 1cm proc to superficial arch at distal edge of the flexor retinaculum
what is allen’s test
a visual test for teh relative contribution of radial and ulnar arteries to the hand
subject asked to raise hand and make clenched fist
examiner compresses both radial and ulnar arteries, when fist is released palmar skin appears pale
examiner releases either one of the arteries and notes the tie for colour return to the hand
fastest artery is the dominant
would you use the dominant artery to take bloos
no - arteries go into vasospasm when needle in them so collapse for a while, so take from least dominant so dominant can maintain blood supply to the hand meanwhile
assess integrity of flexor pollicis longus
nerve - median
examiner holds prox phalanx of thumb whilst distal phalanx is flexed against resistance - the muscle/tendon is deep for palpation
assess integrity of the extensor pollicus longus
radial nerve
thumb extended against resistance at interphalangeal joint
tendon visible at medial border of snuff box and medial to dorsal tubercle of radius
assess integrity of flexor digitorum profundus
ulnar and median nerves
examiner holds prox IP joint in extended position, while distal IP joint is flexed against resistance
assess integrity of FDS
median nerve
each digit assessed individually
non-test fingers are held in full extension by examiner while prox IP joint of test finger is flexed against resistance
assess integrity of extensor digitorum
radial nerve
forearm is pronated and the digits extend at MCP joints
examiner applies resistance on prox phalanges
tendons become visible and palpable on dorsum of hand
muscle belly is palpable on forearm
assess integrity of dorsal interossei
ulnar nerve
examiner holds adjacent extended and adducted fingers of subject between thumb and index finger while subject attempts to abduct them
assess integrity of palmer interossei
ulnar nerve subject holds slip of paper between adjacent fingers taht are extended and adducted
the subject is asked to close the fingers tightly on the paper while the examiner attempts to withdraw it
movement of flexor digitalis superficialis *
flex fingers powerfully
median nerve
muscle that only flexes the last phalanx
flexor digitalis profundus
ulnar and mendian
how many hypothenar muscles are there and innervation
3
ulnar
nerve supply of the intrinsic muscles of the hand *
adductor pollicus - ulnar
thenar - median
hypothenar - ulnar
muscles that move the digits *
extension - radial nerve
- extensor digitorum
- extensor indicis
- extensor digit minimi
hypothenar muscles - innervation ulnar nerve - lateral to medial, extensor flexor oponens digiti minimi
lumbricals
interosseus muscles
flexion
- FDP - median nerve to index and middle fingers, ulnar to ring and little
- FDS - median nerve
what is mallet finger *
when the end of the finger bends in towards the palm because there is damage to the extensor digitorum tendon
explain the spread of infection in tendinous sheaths *
in flexor tendinous sheaths it is a sergical emergancy because they are closed compartments, this is not true in extensor sheaths
in flexor infection can lead to necrosis
what is the blood supply of the digits *
radial - thumb and lateral side of index
ulnar- medial side of index and other digits
