hand Flashcards
___ musc, ___ bones, ___ articulations of the hand
29
19
19
wrist/carpus = ___ carpal bones
8
T/F: metacarpal = metacarpus
F: all 5 metacarpals together
CMC joint consists of
Prox end of metacarpals and distal row of carpal bones
MCP joint consists of
Metacarpals and prox phalanges
T/F: MCP = convex in frontal plane only
F: frontal and sagittal
What do the palmar plates prevent?
Hyperext
What are the 2 interphalangeal joints?
PIP and DIP
T/F: thumb= 3 phalanges and 1 intercarpal joint
F: 2 phalanges
Palmar side of wrist contains ___ & ___ wrist creases
Prox and distal
T/F: the distal wrist crease marks loc of the prox margin of the transverse carpal lig
T
T/F: digit #4= shortest and stoutest
F: #1
T/F: digit #2= longest and each= shorter than previous
T
Palmar surface of shaft of metacarpal = convex/concave longitudinally
Concave
Distal end of each metacarpal = ___ head
Convex
T/F: metacarpal neck = common site of fracture (esp #5)
T
T/F: the thumb metacarpal= similar plane as digits #2-5
F: thumb= different plane
The thumb= rotated 90 deg __
Medially
T/F: thumb dorsal surface face of bones= laterally, palmar= medially, radial= ant, ulnar= post
T
Prox and middle phalanges = ___ base and ___head
Concave
Convex
Distal phalanx = ___ base
Concave
What static, rigid arch forms the carpal tunnel?
Prox transverse arch
(formed by distal row carpal)
T/F: lunate = keystone of prox transverse arch
F: capitate
What mobile arch passes through the MCP joints?
Distal transverse arch
T/F: metacarpals #1,4,5 fold around more stable #2,3
T
What is the keystone of the distal transverse arch?
MCP joints of central metacarpals
What arch follows the general shape of digits #2&3 (/rays)
Longitudinal arch
Prox end of longitudinal arch= attached to ___, distal end?
CMC
Mobile
What is the keystone of longitudinal arch?
2&3 MCP joints
T/F: digits 2&3 = keystone for proximal and longitudinal arches
F: longitudinal and distal
T/F: planes of motion of thumb = oppo fingers
T
CMC joint = ___ region of hand
Prox
T/F: 4&5 CMC joints = rigid –> fixed central pilar
F: 2&3
(4&5 = mobile, fold around pilar)
CMC joint shape = __ metacarpal on ___ hamate
Convex
Concave
Radial central metacarpals provide form attachment points for which musc?
Extensor carpi radialis longus
Extensor carpi radialis brevis
Flexor carpi radialis
ADD pollicis
What joint improves effectiveness of grasp
CMC
T/F: CMC of thumb = saddle
T
Radial collateral and post oblique lig= enhances ___
Proprioception, joint protection, NM control of opposition
T/F: post oblique lig = most ruptured
F: ant
Most lig of CMC = taut w/ thumb in _______
Ext
ABD
Opposition
T/F: common dislocation thumb = radially
T
Saddle joint trapezium POV
Concave P-D
Convex M-L
T/F: AoR for CMC joint in all planes of motion = concave part of articulation
F: convex
Max ABD thumb = __ deg ant to plane of palm
45
ABD thumb = ___thumb moving on___ trapezium
Convex
Concave
Full ABD of CMC joint elongates most lig of joint and what musc
ADD pollicis
ABD CMC thumb stretches what lig and activates what musc?
Post oblique lig
Opponens pollicis
T/F: forces fr both activated musc and stretched lig= imp in promoting maximal congruity and stability of CMC joint once in full opposition
T
During CMC thumb flex, rotates ___, ext?
Medially
Laterally
Flex thumb = __ metacarpal surface on ___ trapezium
Concave
Convex
What are the 2 phases of opposition?
1: thumb metacarpal ABD
2: ABD metacarpal flexes and medially rotates across palm –> fingers
Full opposition includes __ deg of medial rotation @ thumb
45-60
T/F: MCP formed between concave metacarpal heads and convex prox surface of prox phalanges
F: convex met heads, concave prox phalanges
Collateral lig of MCP attaches on/near post tubercle of met head. What are the 2 distinct parts?
Dorsal cord
Accessory
T/F: dorsal cord= thinner, accessory= thicker
F: dorsal= thick
Accessory= thin
Dorsal cord attaches distally to ___ region of prox end of phalanges
Palmar
Accessory part attaches distally along edge of ___ plate
Palmar
What is 1’ func of palmar/volar plates?
Strengthen structures of MCP joints and limit extremes of ext
Concave components of MCP include:
Arctic surface prox phalanx
Collateral lig MCP
Dorsal surface of palmar plate
Overall ranges of flex/ext MCP gradually inc from __ to __ digit?
Digit #2 –> #5
Digit #2 flex ___, #5?
90 deg
110-115 deg
MCP ext passively beyond neutral for a range of = ___
30-45 deg
T/F: ABD and ADD @ MCP occur @ about 20 deg on both sides
T
Arthrokin MCP = ___ arctic surface of phalanx on ___ met head
Concave
Convex
What part of collateral lig = isometric in length throughout flexion and extension
Accessory
T/F: most of cord of collateral lig= slacken in 0 deg ext
T
ABD and ADD of MCP fingers= sig less when motions performed in full ___ than full ___
Flexion
Extension
MCP fingers: most of cord of collateral lig= taut in near full ___
Flexion
MCP joint of thumb concave vs convex:
Convex met head
Concave prox surface of prox phalanx
T/F: active and passive motion @ MCP thumb= sig less than fingers
T
Fr full ext, (thumb MCP) prox phalanx thumb can actively flex ___ deg across palm toward middle finger
60
T/F: thumb MCP can do flex/ext and ABD/ADD
F: flex/ext ONLY
ABD/ADD = limited (accessory mvt)
T/F: skier’s injury (leg external ABD torque @ MCP) injures radial collateral lig
F: ulnar
What is the rupture point for ulnar collateral lig?
45 deg ABD
(most vulnerable to rupture when ABD torque = applied 1/ MCP flexed @ 30 deg)
Head of prox phalanx= ___ rounded condyles separated by shallow central groove
2 (convex)
T/F: DIP= surrounded by radial and ulnar collateral lig
F: PIP
PIP, cord of collateral lig limits ___, accessory?
ABD and ADD
Blends w/ and reinforces palmar/volar plate
What is the primary structure that limits hyperextension of PIP joint?
Palmar plate
T/F: palmar surface of plates= attachment for base of fibrous digital sheath (houses tendon extrinsic finger flex)
T
What is the check-rein lig?
Prox-lat region of each palmar plate @PIP thicken longitudinally form fibrous tissue which reinforce prox attachment of plate and assist in limiting hypertext joint
T/F: PIP and DIP both have check-rein lig
F: only PIP
T/F: flexion @PIP and DIP= greater in radial digits
F: ulnar
When immobilized, PIP and DIP= positioned in near ext why?
Pos= stretch palmar plates, reducing likelihood of flexion contracture
Thumb allows active flexion of ___ deg, IP joint thumb= passively ext beyond neutral to about ___ deg
70
20
What is tabes dorsalis?
Condition affects sensory/afferent tracts w/in spinal cord
What nerve innervates extreinsic musc of hands?
Radial
Extrinsic musc of hand have prox attachment ___
Forearm (or as far as epicondyles of humerus)
T/F: intrinsic musc of hand= attach prox and distally w/in hand
T
T/F: radial n innervates all extrinsic extensors on palmar side of hand
F: dorsal
Median n innervates most of the ___ (lat portion palm)
Extrinsic flexors
T/F: ulnar n innervates most medial musc (medial palm)
T
C6 =___, C7=___, C8=___ digits
1,2
3
4,5
T/F: FDP splits to allow FDS to attach to distal phalanx
F: FDS splits
What musc is the primary PIP flexor? DIP flexor?
FDS
FDP
T/F: FDP digit #2 can be controlled indep of oth digits
T
What does FPL do?
Flex thumb IP joint
T/F: FPL exerts substantial flex torque @ MCP and CMC joints thumb
T
What synovial sheath is distal to carpal tunnel?
Ulnar synovial sheath (surrounds FDS and FDP tendons)
Where does radial synovial sheath attach?
Tendon FPL
T/F: fibrous digital sheath are anchored to phalanges and palmar plates
T
What synovial sheath surrounds extrinsic flexor from distal wrist crease to DIP and serves as lubrication to tendons?
Digital
What are the 5 pulleys?
3 cross joints, 2 attach to shaft phalanges
What is the role of pulleys?
Hold tendon @ constant distance fr MA during flexion
What is tenosynovitis?
Inflamm flexor tendons and surrounding synovial membranes
T/F: flexion and extension will –> more pressure for carpal tunnel
T
What is the best position to help relieve pressure of carpal tunnel?
Neutral
What is tenodesis?
Stretch musc passively across 1 joint –> creates passive mvt @ oth joints the musc crosses
(ext wrist, fingers flex naturally)
What are the extrinsic finger extensors?
EDC
EI
ED Min
T/F: extensor indicis= predominant finger ext bc cross sectional area
F: EDC
T/F: extensor tendons lack pulley and defined digital sheath
T
T/F: central band of extensor mech = extension of EDC
T
T/F: lateral band = backbone of extensor mech
F: central band
T/F: lateral band of extensor mech= wraps around joint @ prox phalanx
F: distal
Central band attaches to ___ phalanx, lateral band?
Middle
Distal
T/F: dorsal hood connects tendon to palmar plate and provide attachment to lumbricals and interossei
T
Dorsal hood stabilizes extensor tendons relative to __
MCP joint
T/F: oblique retinacular lig insert distally in lateral band and coord mvt beta PIP and DIP fingers
T
Isolated cxn EDC prod __ @ MCP joint
Hyperext
T/F: EDC can fully ext PIP and DIP alone
F: need activated intrinsic musc fingers
What musc make up anatomic snuff bos? (extrinsic extensors thumb)
EPL
EPB
AbPL
Which tendons pass through the 1st dorsal compartment w/in extensor retinaculum of wrist
AbPL
EPB
Where does tendon EPL cross?
3rd compartment (groove med to dorsal tubercle of radius)
Which joints does EPL ext?
CMC, MCP, IP thumb
T/F: EPL only ext CMC joint
F: also ADD
What joints does EPB ext?
CMC and MCP
T/F: AbPL ext only CMC
T
T/F: EPL and ECB= radial dev
F: EPL and AbPL
3 thenar musc prox attachment
Transverse carpal lig and adjacent carpal bones
T/F: FPB and OP attach distally to radial side of base of prox phalanx
F: AbPL and FPB
(OP= radial border of thumb metacarpal)
T/F: AbPL attaches to extensor mech/expansion
T
Median n injury results in ___ opposition and flattens the thenar area of hand
Disabled
Med rot of opposition occurs w/ which musc? Flexion and ABD?
OP
All 3 thenar
T/F: ADD policies > ABD pollicis
T
Median n injury –> ___ contracture of CMC thumb
ADD
Where is the ABD DM insertion?
Pisiform (stable insertion for FCU tendon)
What is the func of hypothenar?
Cup ulnar border of hand
Ulnar lesion results in
Flat hypothenar eminence
Ulnar n injury –> clawing, what’s position?
Hyperext MCP
Flex IP
Ulnar lesion paralyzes what musc?
ADD policies
All interosseous musc
2 heads ADD policies attach __ side of prox phalanx
Ulnar
T/F: greatest flexor and ADD torque @CMC = ADD pollicis
T
What 2 n innervate lumbricals?
Median n (lateral)
Ulnar n (medial)
Actions of lumbricals?
Flex MCP, ext DIP and PIP
Interossei = __&__
PAD
DAB
PAD
ADD digits #2,4,5
DAB
ABD digits 2,3,4
T/F: ABD digit #5= dorsal interossei
F: ABD digiti minimi
T/F: interossei and ABD digiti minimi= dynamic stabilizers MCP joints
T
Cxn interossei = __ MCP, __ IP
Flex
Ext
T/F: lumbricals stronger than interossei
F: interossei bc prod lrg force over shorter cxn distance
Intrinsic + pos? Extrinsic +?
Flex MCP, IP ext
Ext MCP, IP flex
Forces fr FDP and FDS flex __ joints of fingers
All 3
What is prehension?
Ability fingers and thumb to grasp/seize, holding, securing, picking up obj
If unable to pinch, what musc do you compensate w/ for ulnar n lesion?
FPL (median n) (partially flex IP)
What is froment’s sign an indication of?
Ulnar n lesion
What is zig-zag deformity? Eg?
Collapse of multiple interconnected joints in alternating directions
Advanced RA
Common deformity pos?
CMC flex and ADD
MCP hypertext
IP flex
T/F: finger flexors generate bowstring force in palmar direc when gripping
T
Weakened lig (w/ RA) –>
Bowstringing force dislocating MCP completely
Ulnar drift = deformity @MCP of ____
Excessive ulnar dev and ulnar translation (slide) prox phalanx
T/F: healthy hand, transverse fibers dorsal hood and radial collateral lig maintain extensor tendon over AoR
T
W/ RA, transverse fibers dorsal hood ruptures allowing EDC tendon to slide ___ side of AoR
Ulnar
Ulnar drift may be assoc w/
Wrist instability
