WRIST Flashcards
1
Q
Which proximal carpal bone does not articulate with the radius?
A
pisiform
2
Q
How many degrees of ulnar tilt does the radius have?
A
around 20
3
Q
What does the FCU attach to?
A
pisiform, hook of hamate, base of 5th metacarpal
4
Q
Which 2 carpal bones are most bound together?
A
capitate & hamate
5
Q
Are volar or dorsal ligaments stronger?
A
volar
6
Q
What is the term for when compressive forces being applied makes the middle segment collapse?
A
intercalated
7
Q
Which flexor contributes to the cupping of the hand?
A
FCU
8
Q
True or False: FDS produces more torque than FDP at MCP.
A
T
(FDP crosses more joints -> more active insufficiency -> less torque at MCP)
9
Q
What 2 compound joints make up the wrist complex?
A
radiocarpal & midcarpal
10
Q
What type of joint is the wrist & how many degrees of freedom does it have?
A
- biaxial
- 2: flx/ext & rad/uln dev
11
Q
How many degrees of flx/ext does the wrist have?
A
- flx: 65-85
- ext: 60-85
12
Q
How many degrees of rad/uln dev is there?
A
- rad: 15-21
- uln: 20-45
13
Q
What forms the radiocarpal joint proximally & distally?
A
- radius & disc (TFCC) proximally
- scaphoid, lunate, & triquetrum distally
14
Q
Prox segment of radiocarpal joint: lateral radial facet w/ __________, medial radial facet w/ lunate, TFFC w/ __________.
A
scaphoid, triquetrum
15
Q
Which way is the radius angled?
A
volarly/ulnary
16
Q
Which ligaments connect the TFCC medially?
A
dorsal & volar radioulnar
17
Q
What does the TFCC connect distally to?
A
- ECU
- triquetrum
- hamate
- base of 5th metacarpal
18
Q
What carpal bones make up the proximal carpal row?
A
- scaphoid
- lunate
- triquetrum
19
Q
What ligaments is the proximal carpal row connected by?
A
scapholunate interosseous & linotriquetral interosseous
20
Q
True or False: Pisiform is in the proximal row & supports the radius.
A
F
(just increases MA for FCU)
21
Q
True or False: Prox radiocarpal segment is sharper than distal making it an incongruent joint.
A
F
(distal is sharper)
22
Q
Scaphoid & lunate receive ___% of axial load & TFFC receives ___%.
A
80 & 20
23
Q
Ulnar (positive/negative) variance = short ulna w/ thicker TFCC –> keinbock’s disease (AVN of lunate).
A
negative
24
Q
Ulnar (pos/neg) variance = long ulna following radial fracture.
A
positive
25
Most ligaments & muscles that cross the radiocarpal joint also contribute to the stability of the midcarpal joint except for which?
FCU
26
What forms the midcarpal joint proximally & distally to form an overall reciprocally concave-convex configuration?
- prox: scaphoid, lunate, triquetrum
- distally: trapezium, trapezoid, capitate, & hamate
27
Which ligaments connect carpals to radius/ulna proximally or metacarpals distally?
extrinsic
28
Which ligaments interconnect carpals?
intrinsic/intercarpal/interosseous
29
What are the 2 extrinsic volar ligaments?
radiocarpal & ulnocarpal
30
Which extrinsic ligament are these associated with? - radioscaphocapitate - radiolunate - radioscapholunate
volar radiocarpal
31
Which ligament is the extension of the volar radiocarpal ligaments?
radial collateral
32
What is the term for the combination of these? - TFCC - ulnolunate lig - ulnar collateral lig
ulnocarpal lig complex
33
What are the 3 intrinsic volar carpal ligaments?
- scapholunate
- lunotriquetral
- v-deltoid
34
Which dorsal carpal ligament converges on triquetrum & helps to offset sliding of proximal carpal condyle on inclined radius?
dorsal radiocarpal
35
Which dorsal carpal ligament courses horizontally from triquetrum, lunate, scaphoid, & trapezium?
dorsal intercarpal
36
The 2 dorsal carpal ligaments forming a horizontal V stabilize ________ during wrist ROM.
scaphoid
37
Which carpal bone is the keystone of the wrist that contacts 7 other carpal bones?
capitate
38
What 7 bones connect to capitate?
- hamate
- lunate
- scaphoid
- trapezoid
- 2nd metacarpal
- 3rd metacarpal
- 4th metacarpal
39
From full flexion, extension begins with distal carpal roll gliding (anterior/posterior) on proximal row to neutral when capitate & scaphoid become close-packed.
posterior
40
In extension, after capitate & scaphoid become close-packed, distal row & scaphoid move on lunate & triquetrum to 45 degrees when _________ & _________ lock.
scaphoid, lunate
41
In extension, after scaphoid & lunate lock, proximal row extends on _________/disc to fully extend close-packed.
radius
42
In radial deviation, carpals all slide (radially/ulnarly) on radius with flexion of proximal row & extension of distal row (closed-packed).
ulnarly
43
True or False: There's a good amount of deviation when the wrist is fully extended (close-packed).
F
## Footnote
(little)
44
Bones are splayed during wrist _________ (loose-packed).
flexion
45
Dorsal intercalated segmental instability is ligamentous laxity/tear of ___________ ligament --> lunate extend or move dorsally (along with triquetrum) --> separate lunate from scaphoid.
scapholunate
46
What is it called when DISI becomes a progressive degenerative problem?
scapholunate advanced collapse
47
Volar intercalated segmental instability is ligamentous laxity/tear of _______________ --> lunate (flex/extend) or move more volarly with scaphoid --> separate lunate from triquetrum.
Lunotriquetral lig, flex
48
What is the optimal position for grip strength?
slight wrist extension with ulnar deviation
49
True or False: Palmaris longus helps with radial deviation.
F
## Footnote
(NONE)
50
What carpal bone increases the mechanical advantage of FCU?
pisiform
51
What are the volar wrist muscles (flexors)? Which ones are the main ones?
- PL*
- FCR*
- FCU*
- FDS
- FDP
- FPL
52
Flexor retinaculum & transverse carpal ligament enclose all volar wrist muscles except for which 2?
PL & FCU
53
Flexor retinaculum & transverse carpal ligament prevent bowstringing of tendons & help with length-tension of which 2?
FDS & FDP
54
What are the dorsal wrist muscles (extensors)? Which ones are the main ones?
- ECRL*
- ECRB*
- ECU*
- EDC
- EPL, EPB, APL
55
ECRL inserts into ___ MC & is best in wrist extension & radial deviation.
2nd
56
ECRB inserts into 3rd MC & is active in all grasp/release except ________.
supination
57
What makes up the CMC joint?
distal carpal row & base of 2nd-5th MC joints
58
Which ligament tethers 2-4 MC heads together & limits abduction?
deep transverse metacarpal
59
What 3 things create the proximal transverse (carpal) arch? What else does this form?
- curved shape of carpals
- transverse carpal ligament
- intercarpal ligaments
- carpal tunnel
60
What type of joints are 2nd-4th CMC? How many degrees of freedom do they have?
- plane synovial
- 1: flx/ext
61
Which CMCs are fixed & have stable axis? Which ones move?
- fixed: 2/3
- move: 4/5
62
What type of joint is the 5th CMC? How many degrees of freedom does it have?
- saddle
- 2: flx/ext, abd/add
63
Which of the 3 palmar arches is fixed? Which are mobile?
- fixed: prox
- mobile: distal & longitudinal
64
Which arch is formed from adjustable positions of 1, 4, 5 MC heads around fixed CMC joints at 2 & 3?
distal
65
Which arch is proximal to distal & includes all fingers?
longitudinal
66
Which muscles assist arches?
- finger flexors
- ODM
- FCU
67
MCP joints have (convex/concave) metacarpal head proximally & concave base of first phalanx distally.
convex
68
What type of joint is MCP? How many degrees of freedom does it have?
- condyloid
- 2: flx/ext, abd/add
69
MCP has lax capsule in (flx/ext) to allow passive axial rotation of proximal phalanx.
ext
70
How many collateral ligaments does the MCP joint have? What are they?
2 (radial & ulnar)
71
MCP joint volar plates do: - increase joint congruency - add stability - limits __________ - supports long arch - resists tensile stress in extension - resists compressive forces from objects - glides down in _________ - prevents pinching of tendons.
- hyperextension
- flexion
72
Which MCP collateral ligament is more taut in flexion? Which is more in extension?
- flex: collateral ligament proper
- ext: accessory collateral ligament
73
MCP has limited _________ during flexion because of collaterals & bicondylar MC head.
abduction
74
What protects joints in compression & increases surface area for MCP, PIP, & DIP joints from dorsal extensor hood?
fibrocart projections
75
What is the MCP ROM for 2nd & 5th flexion?
- 2nd: 90
- 5th: 110
76
Abduction/adduction for MCP is available in extension; which MCPs is this most seen in?
2nd & 5th
77
What type of joints are PIP & DIP? How many degrees of freedom do they have?
- true synovial
- 1: flx/ext
78
True or False: Each PIP & DIP has joint capsule, volar plate, & 2 collateral ligaments.
T
79
Base of phalanx has 2 shallow (convex/concave) facets with central ridge (proximal surface larger).
concave
80
(PIP/DIP) has some hyperextension.
DIP
81
What is the flexion ROM for PIP & DIP?
PIP: 100-135
DIP: 80-90
82
What are the 2 extrinsic finger flexors?
FDS & FDP
83
Which extrinsic finger flexor primarily does PIP, contributes to MP with larger MA, & has a split?
FDS
84
What are finger flexors dependent on for good length-tension?
wrist extension
85
What type of grip is used when a tool is larger on the ulnar side for greater length & force?
pistol
86
True or False: Retinaculae tether tendons to hand & prevent bowstringing while bursa & synovial filled sheaths facilitate gliding.
T
87
What bursa envelops FDS & FDP?
ulnar
88
What does the radial bursa cover (1 muscle)?
FPL
89
How many annular & cruciate pulleys are there alongside PA pulley?
5 & 3
90
What provides vascular supply?
vincula tendinum
91
Which 3 finger extensors pass under extensor retinaculae & have individual bursa or sheath?
- EDC
- EIP
- EDM
92
Where does EDC tendon merge with extensor expansion/hood?
MP joint
93
EI & EDM enter into _________ tendons of index & 5th --> independence of those digits.
EDC
94
What 3 extensors (that are also synergists for wrist extension) are the only MP extensors since they cross MP, attach to extensor hood & sagittal bands to prevent bowstringing?
- EDC
- EI
- EDM
95
Central tendon extends which joint?
PIP
96
Lateral bands blend into terminal tendon with triangular ligament & extend which joint?
DIP
97
IP extension requires __________ along with interossei & lumbricals.
EDC
98
What muscles attach to sides of MC & distally attach to proximal phalanx & dorsal hood?
DI & VI
99
What muscles come from FDP tendons to lateral bands?
lumbricals
100
What structure comes from proximal phalanx, annular, cruciate pulleys & attaches distally to lateral bands past PIP (volar to PIP, dorsal to DIP)?
oblique retinacular ligament
101
Extensor tendons are dorsal to MP & pull on _________ bands.
sagittal
102
Simultaneous IP extension needs active force from which muscles?
- DI
- VI
- lumbricals
103
Isolated EDC causes active MP __________ with passive IP ________ --> clawing or intrinsic minus (prox phalanx collapses).
hyperextension, flexion
104
Isolated contraction of interossei & lumbricals results in MP ________ & IP _________ (lumbrical grip).
flexion, extension
105
What are 2 ways IP extension can occur?
- active: intrinsics or EDC
- passive: EDC with MP flexion (ORL contributes)
106
DIP _________ with PIP extension occurs when ORLs are dorsal to PIP.
flexion
107
True or False: If FDS flexes PIP, DIP can still be actively extended despite distal pull of dorsal hood.
F
108
2-4 DI have proximal & distal attachments; what joints do the proximal attachments act on? What about distal?
- prox: MP
- distal: IP & MP
109
When MP is ____________, interossei MA is ineffective for flexion but MA is good for abduction/adduction.
extension
110
When MP is flexed, good MA for flexion as collateral ligaments become taut & prevent what motions?
abduction/adduction
111
Which fingers have weaker IP extension because there's only 1 interossei there?
2nd & 5th
112
Contraction of lumbricals tenses lateral band so there's extension in which joints? (more effective than interossei)
PIP & DIP
113
True or False: MA of lumbricals is greater than interossei for MP flexion & functionally stronger.
F
## Footnote
(weaker because smaller cross section of muscle & attachment to FDP)
114
Which intrinsic position is lumbrical & interossei activation without extrinsic finger flexors or extensors?
plus
115
What type of joint is the CMC joint of thumb (trapeziometacarpal)? How many degrees of freedom does it have?
- saddle
- 2 degrees: flx/ext, abd/add
116
What is the value of flx/ext ROM for CMC joint of thumb?
53 degrees
117
What is the value of abd/add ROM for CMC joint of thumb?
42 degrees
118
Which intrinsic position is lumb & interossei activation w/o extrinsic finger flexors or extensors?
plus
119
What type of joint is the CMC joint of the thumb (trapeziometacarpal)? How many degrees of freedom does it have?
- saddle
- 2 degrees: flx/ext, abd/add
120
What is the value of flx/ext ROM for CMC joint of thumb?
53 deg
121
What is the value of abd/add ROM for CMC joint of thumb?
42 deg
122
What is the value of circumduction or opposition for CMC joint of thumb?
17 deg
123
What does the CMC joint of thumb's lax capsule with ligaments tether together?
1st & 2nd base MC
124
When is CMC joint of thumb in closed packed?
extreme abd/add
125
True or False: Opposition of CMC joint of thumb is sequentially abd, flx, add w/ rotation.
T
126
What type of joint is the thumb MP? How many degrees of freedom does it have?
- condyloid
- 2: flx/ext (half of other MPs), abd/add (minimal)
127
Thumb MP function is to add flex range to thumb in ___________.
opposition
128
What are the 4 extrinsic thumb muscles that act on all joints they cross?
- FPL
- EPB
- EPL
- APL
129
Which muscles make up the snuff box?
EPB, EPL, APL
130
What are the 4 intrinsic thumb muscles that are all active in grasping?
- OP
- ABD PB
- FPB
- ADD POL
131
What are these examples of? - cylindrical - spherical - hook - lateral prehension
power grip
132
What are these examples of? - pad to pad - tip to tip - pad to side
precision handling
133
What are the degrees for functional position of wrist/hand?
- wrist: 20 deg ext
- ulnar dev: 10 deg
- MPs: 45 deg
- PIPs: 30 deg
- DIPs: slight flx
