WHF - structure, function, anatomy Flashcards
Mechanical purpose of shoulder, elbow, WFH
shoulder - mobility and gross placement of handelbow - stabilityWHF - strength and precision
How may carpals, metacarpals, and phlanges
8 carpals, 5 metacarpals, 14 phalanges
name the carpals
scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, hamate
1st Metacarpal lines up with
Trapezium
2nd metacarpal lines up with
trapezoid
3rd MC lines up with
Capitate
4 and 5 MC lines up with
Hamate
Pisiform floats on
triquetrum
commonly fractured
scaphoid
commonly dislocated
lunate
proximal articulating surfaces of long bones
concave
distal articulating surfaces of long bones
convex
purpose of sesamoid bones on first MC
improve mechanical line of pull of the flexor pollicis brevis, abductor pollicis brevis, adductor pollicis muscles
Distal radioulnar joint - degrees of freedom - movements
ulnar head/ulnar notch
1 degree of freedom
pronation and supination
Radiocarpal joint
ellipsoid joint
2 degrees of freedom
flexion and extension
radial and ulnar deviation
fibrous capsule formed by distal radius and the scaphoid and lunate
RCL
radial collateral ligamentlimits ulnar deviation becomes taut when the wrist is at the extreme ranges of flexion and extension
Palmar radiocarpal ligament
controls motion and wrist stability
Dorsal radiocarpal ligament
limits flexion
TFCC
triangular fibrocartilanginous complex-articular disc-dissipates stress imposed on forearm during loading-stabilizes distal radioulnar joint
Intercarpal joints
allow for gliding movements
First CMC joint
2 degrees of freedom synovial saddle joint flexion and extension, abduction and adduction accessory motion: opposition and reposition
CMC joints 2-4
plane synovial joint
1 degree of freedom
flexion and extension
CMC joint 5
2 degrees of freedom
flexion and extension
abduction and adduction
MCP joints
condyloid joints
2 degrees of freedom
flexion and extension
abduction and adduction
collateral ligaments at fingers
protect against valgus and varus forces make gripping less dependent on dynamic stability
IP joints
1 degree of freedom
flexion and extension
natural position of hand
slight flexion
Extensor muscles
Extensor muscles
location: posterolateral forearm
6 compartments
radial nerve innervation
extensor carpi radialis longus/brevis extensor carpi ulnaris extensor digitorum communis extensor pollicis longus extensor pollicis brevis abductor pollicis longus extensor indicus
all secured by extensor retinaculum
increase efficiency of the muscles’ pull and prevents “bow stringing” when the wrist is extended
Flexor muscles
Flexor Muscles Location: anteromedial forearm 2 compartments flexor carpi radialis, palmaris longus (absent in 12-15% of population) flexor carpi ulnaris flexor digitorum superficialis flexor digitorum profundus flexor pollicis longus
median nerve innervation
(fourth and fifth - ulnar nerve)
Palmar muscles groups
thenar central, hypothenar, adductor interosseous compartments
muscles of thenar eminence
abductor pollicis brevis, flexor pollicis brevis, opponens pollicis
muscles of hypothenar eminence
abudctor digiti minimi, flexor digiti minimi brevis, opponens digiti minimi muscles
To prevent bowstringing
series of pulleys restrain and guide the tendonsduring flexion and extension of the fingers
flexor tendons require how much more excursion than extensor tendons
4x
annular pulleys
tunnels for tendons
cruciate pulleys
pliable, allow annular pulleys to move towards each other in flexion
4 Lumbrical muscles
flex MCP, extend PIP and DIP
Palmar aponeurosis equals
volar plate
Ulnar
passes through tunnel of guyon.palmar/dorsum - 1/2 ring finger, pinky finger.
median
runs through carpal tunnellateral palm, 1/2 ring finger, fingers 3-1.dorsum - fingers 1,2 and half of ring finger
Radian nerve
base of thumb, back of hand near thumb below 1st and 2nd fingers
Carpal tunnel
fibro-osseus structurefloor formed by proximal carpal bonesroof - transverse carpal ligaments
PVD
peripheral vascular disease (Raynaud’s)
Russell’s signs
abrasions, small cuts, callosities over dorsal surface of MCP or IP joints-outward signs of bullimia
Drop wrist associated with
radial nerve
Trigger finger
stenosing tenosynovitisnodule in flexor tendonaffects MCP flexion and extension
Ape Hand
median nerve pathologyweakness in thenar eminencepulls thumb medially
Bishop’s Deformity
ulnar nerve, hypothenar muscles, flexion in PIP and DIP joints, extension limited
Claw Hand
ulnar and median nerveextension of MCP, flexion of PIP and DIP
Dupuytren’s Contracture
excessive flexed resting positioncan’t extend MCP and PIP jointsshortening or adhesion of palmar fascia
Swan Neck Deformity
flexion of MCP and DIPhyperextension of PIPvolar plate injuries,malunion, trauma, arthritis
Volkmann’s Ischemic Contracture
flexion contraction of wrist and fingers,limited extensiondecreased blood supply
Jersey Finger
avulsion of extensor digitorum longus tendon-can’t actively extend distal phalanx
Mallet Finger
avulsion of extensor digitorum longus tendoncan’t actively extend distal phalanx
Boutonniere Deformity
rupture of central extensor tendonrupture of volar plate-extension of MCP and DIP joints-flexion of PIP joint
Hard end feels
radial deviation, MCP flexion, PIP flexion
Soft end feels
thumb flexion, thumb adduction
numbness on dorsal hand correlates with what nerve pathology
ulnar nerve in elbow
numbness on palmar side of hand correlates with
ulnar nerve near tunnel of guyon
distal forearm fractures common in
children
Colles fracture
any fracture of distal radius
scaphoid fracture common in
15-30 year olds and younger males
concerns with scaphoid fracture
blood supply from radial artery compromised - necrosisPreiser’s disease - osteoporosis of scaphoidnonunion
MOI of schaphoid fracture
foosh, land on palm, hyperextension of wrist
Hamate fractures, MOI
hook of hamateMOI - foosh or trauma from golf club or bat,axial loadcould compress ulnar nerve - symptoms in fingers 4 and 5.
concerns with hamate fractures
nonunion, vascular supplycan be removed
Lunate dislocation
lunate is disassociated from other carpals
perilunate dislocation
proximal carpal row being stripped from around the lunate
Lunate MOI
high energy forced hyper extension of wrist
Murphy’s sign
depressed third knuckle - lunate dislocation
Wrist sprains
scapholunate ligaments - most commonly sprained
Watson test
positive for tear - clunk with pain
TFCC injury
traumu, or repeated injury
MOI of TFCC
forced hyperextension w/ pronating force; rotary force, repeated weight bearing
Carpal tunnel syndrom
compression of median nerve-fibrosis of the synovium of flexor tendons secondary to tenosynovitis-repeptive microtraumau-caused by poor biomechanics, poor posture, obesity, pregnancy, typing, work related activities, diabetes,
CTS signs and symptoms
numbness or pain and thumb, index, middle, lateral half of ring finger (median nerve)
Boxer’s fracture
common in young men, punching somethingfracture of 5th MC
Collateral ligament injuries
unilateral stress applied to extended finger
Dequeravain’s syndrome
finkelstein’s test-tenosynovitis of the extensor pollicis brevis, abductor pollicis longus tendonswomen 20-40repetitive radial deviation
UCL sprain
limits opposition and decreases grip strengthhyperabduction or hyper extenstion”gamekeeper’s thumb”pain on ulnar side, can’t pinch or grasp
Bennett’s fracture
base of first MC
Splinting jersey finger
DIP joint in flexion
Splinting mallet finger
dIP joint in extension
Splinting boutonniere finger
PIP and DIP joints in extension
radial collateral and ulnar collateral ligament stress tests
UCL - test with valgus stressRCL - test with varus stress
Valgus and Varus IP tests
tests for collateral ligament sprainavulsion fracture
Laxity of thumb MCP collateral ligaments
valgus stress to thumb UCLsprain or avulsion fracture
Watson’s test
arm in arm wrestling position-apply dorsal pressure with thumb at scapholunate area-move hand from ulnar deviation to radial deviationtests for: scapholunate dissociation
Phalen’s Test
test for carpal tunnel-tingling from irritation of median nerve-patient is standing-overpressure applied though wrist flexion for 1 minute
Finkelstein’s
dequervain’s syndrome
the pisiform improves what?
mechanical efficiency of the flexor carpi ulnaris
history
where is the painMOIprevious historygeneral medical healthSounds or sensationshow long?type of pain, pain scalechanges in activity
keystone of carpal group
lunate