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391 Cards in this Set
- Front
- Back
this joint is also known as a zone of architectural transition between the two bones of the forearm and the 5 metacarpals |
wrist |
|
what type of joint is the wrist?
|
ellipsoidal/biaxial
|
|
what are the two components of the wrist joint?
|
(1) radiocarpal
(2) midcarpal |
|
this carpal bone is in the shape of a peanut
|
scaphoid
|
|
what carpal bone bridges across the midcarpal joint, making it more susceptible to injury?
|
scaphoid
|
|
what carpal bone is the most commonly fractured and is most slow to heal?
|
scaphoid
|
|
the surface of the scaphoid bone is mostly covered with __ cartilage
|
hyaline
|
|
this carpal bone is the keystone of the bones in the proximal row
|
lunate
|
|
is the volar or dorsal pole of the lunate thicker?
|
volar
|
|
in what direction does the lunate tend to dislocate?
|
volarly
|
|
this disease is avascular necrosis of the lunate
|
Keinbock's
|
|
during ulnar deviation, what carpal bone glides distally on the hamate?
|
triquetrum
|
|
what are the four carpal bones of the proximal row?
|
scaphoid, lunate, triquetrum, pisiform
|
|
what carpal bone is the only one with an insertion from a forearm muscle?
|
pisiform
|
|
what forearm muscle inserts on the pisiform?
|
flexor carpi ulnaris
|
|
what other carpal bone does the pisiform function with?
|
triquetrum
|
|
which way does the pisiform move during radial deviation and extension?
|
distally
|
|
which way does the pisiform move during ulnar deviation and flexion (due to the pull of the FCU?)
|
proximally
|
|
this carpal bone has a hook on the palmar side that forms the medial wall of the carpal tunnel
|
hamate
|
|
what carpal bone forms the medial wall of the carpal tunnel?
|
hamate
|
|
what carpal bone forms the lateral wall of Guyon's canal?
|
hamate
|
|
this structure is located between the neurovascular bundle and the flexor tendons in the carpal tunnel
|
hook of the hamate
|
|
what structure attaches at the hook of the hamate, that forms the roof of the carpal tunnel?
|
flexor retinaculum
|
|
the axis of rotation for RD, UD, flexion and extension goes through what carpal bone?
|
capitate
|
|
the capitate is firmly attached to the base of what metacarpal?
|
3rd
|
|
this carpal bone articulates with the scaphoid, capitate, trapezium, and the second metacarpal
|
trapezoid
|
|
what are the four carpal bones of the distal row?
|
trapezium, trapezoid, capitate, hamate
|
|
this carpal bone is the most important link between the carpals and the mobile thumb metacarpal
|
trapezium
|
|
what type of joint does the trapezium form when it articulates with the 1st MC?
|
saddle
|
|
the tubercle of what carpal bone makes up the lateral wall of the carpal tunnel?
|
trapezium
|
|
how much hand function would you lose if you lost the function of your thumb?
|
40-60%
|
|
what carpal bone is contained in the lateral column of the hand?
|
scaphoid
|
|
what carpal bones are contained in the central column of the hand?
|
lunate and entire distal row (trapezium, trapezoid, capitate, hamate)
|
|
what carpal bone is contained in the medial column of the hand?
|
triquetrum
|
|
what column of the hand is mobile and allows thumb movement?
|
lateral
|
|
what column of the hand corresponds to the axis of the hand?
|
central
|
|
what column of the hand allows rotation of the 5th metacarpal?
|
medial
|
|
when palmar concavity deepens, the carpal tunnel deepens due to movement at what joints?
|
intercarpal
|
|
what are the components of the carpal tunnel?
|
(1) all FDS tendons
(2) all FDP tendons (3) flexor pollicis longus tendon (4) median nerve |
|
the concavity of the carpal tunnel plays an important role in balancing the forces of the long finger __ across the wrist with the wrist __
|
flexors, extensors
|
|
the surface of the radius has articulations for what two carpal bones?
|
scaphoid and lunate
|
|
does the triquetrum articulate with the distal ulna?
|
NO! articulates with the articular disc
|
|
how many degrees of palmar tilt is the articular surface of the radius in at the wrist?
|
12º
|
|
how many degrees of medial angulation is the articular surface of the radius in at the wrist?
|
15º
|
|
the palmar tilt of the radius at the wrist allows more movement into what motion?
|
more flexion than extension
|
|
does the radius or the ulna extend further at the wrist joint?
|
radius
|
|
when the scaphoid, lunate, and triquetrum extend on the distal end of radius and articular disc, in what directions are the roll and glide?
|
posterior roll, anterior glide
|
|
what shape are the articulating surfaces of the scaphoid, lunate, and triquetrum at the wrist?
|
convex
|
|
what shape are the distal end of the radius and articular disc of the ulna at the wrist?
|
concave
|
|
what type of joint is the medial side of the midcarpal joint?
|
compound saddle joint
|
|
what type of joint is the lateral side of the midcarpal joint?
|
plane
|
|
at the medial side of the midcarpal joint, what shape are the capitate and hamate?
|
convex
|
|
at the medial side of the midcarpal joint, what shape are the scaphoid, lunate, and triquetrum?
|
concave
|
|
at the lateral side of the midcarpal joint, what shape are the trapezium and trapezoid?
|
concave
|
|
at the lateral side of the midcarpal joint, what shape is the scaphoid?
|
convex
|
|
what are the thicker and stronger ligaments of the wrist, dorsal or volar?
|
volar
|
|
the dorsal ligaments of the wrist are reinforced by what structures?
|
extensor retinacular tunnels
|
|
what are the four extrinsic ligaments of the wrist?
|
(1) dorsal radiocarpal
(2) palmar radiocarpal (3) TFCC (4) radial collateral ligament |
|
in what position is the palmar radiocarpal ligament taut?
|
full wrist extension
|
|
what are the three types of intrinsic ligaments of the wrist?
|
(1) short
(2) intermediate (3) long |
|
what are the most commonly injured intrinsic ligaments of the wrist?
|
intermediate
|
|
what are the three intermediate intrinsic ligaments of the wrist?
|
(1) lunotriquetral
(2) scapholunate (3) scaphotrapezial |
|
this long intrinsic ligament of the wrist is an inverted V, and controls the scaphoid
|
palmar intercarpal
|
|
this intrinsic ligament of the wrist helps to coordinate movements between the scaphoid and lunate
|
scapholunate
|
|
this extrinsic ligament of the wrist (which is part of the palmar radiocarpal ligament) guides scaphoid kinematics; it goes across the waist of the scaphoid so it dorsiflexes and volarflexes around this ligament
|
radioscaphocapitate
|
|
when the wrist extends, does the dorsal pole of the scaphoid go anterior or posterior?
|
posterior/dorsally
|
|
when the wrist flexes, does the dorsal pole of the scaphoid go anterior or posterior?
|
anterior/volarly
|
|
this ligament, which is part of the palmar radiocarpal ligament, acts as a volar sling for the lunate, preventing it from dislocating anteriorly
|
radiolunate
|
|
what three muscles act as important collateral support at the wrist?
|
(1) ECU
(2) EPB (3) APL |
|
what are the three functions of the TFCC?
|
(1) major stabilizer of distal radioulnar joint
(2) stabilizer of ulnar capsule (3) cushion for load bearing between ulnar carpals and distal ulna |
|
what are the five ligaments that provide support/stabilization to the scaphoid?
|
(1) radioscaphocapitate
(2) radioscapholunate (3) scapholunate (4) radial collateral (5) V ligaments |
|
what ligament limits the extremes of volarflexion of the scaphoid?
|
radioscapholunate
|
|
what bones do the V ligaments run between?
|
scaphoid to capitate and triquetrum to capitate
|
|
what is the close packed position of the wrist?
|
full extension
|
|
what is functionally the most important motion at the wrist?
|
extension
|
|
what is the normal range of wrist extension motion?
|
60-75º
|
|
during wrist extension, which way does the scaphoid move (which locks the joint)?
|
dorsiflexes
|
|
what is the normal range of wrist flexion motion?
|
70-85º
|
|
during wrist flexion, which way does the scaphoid move (which unlocks the joint)?
|
volarflexes
|
|
what are three structures that limit wrist extension?
|
(1) thick palmar ligaments
(2) anterior tilt of articular surface of distal radius (3) muscles that flex wrist and fingers |
|
what is the normal range of motion of radial deviation/abduction at the wrist?
|
15-20º
|
|
At what joint does radial deviation movement occur primarily?
|
midcarpal
|
|
during radial deviation, which way do the scaphoid and lunate move (causing the midcarpal joint to be unlocked)?
|
volarflexed
|
|
during radial deviation, which way does the distal row of carpals slide?
|
radially
|
|
during radial deviation, which way does the proximal row of carpals slide?
|
ulnarly
|
|
what is the normal range of motion of ulnar deviation/adduction at the wrist?
|
35-40º
|
|
in what forearm position is there greater ROM into ulnar deviation?
|
supinated
|
|
during ulnar deviation, which way does the scaphoid move (causing the midcarpal joint to be locked)?
|
dorsiflexed
|
|
what two movements does the triquetrum do during ulnar deviation?
|
(1) telescopes distally on hamate
(2) dorsiflexes |
|
during ulnar deviation, which way does the proximal row of carpals slide?
|
radially
|
|
during ulnar deviation, which way does the distal row of carpals slide?
|
ulnarly
|
|
what is the minimum range of wrist flexion required for most ADLs?
|
40º
|
|
what is the minimum range of wrist extension required for most ADLs?
|
40º
|
|
what is the minimum range of wrist RD required for most ADLs?
|
10º
|
|
what is the minimum range of wrist UD required for most ADLs?
|
30º
|
|
this instability at the wrist occurs when the lunate stays relatively dorsiflexed due to injury of the scapholunate ligament; allows less flexion ROM
|
DISI (dorsal intercalated segmental instability)
|
|
this instability at the wrist occurs when the lunate remains in a relatively volarflexed position due to injury of the lunotriquetral ligament
|
VISI (volar intercalated segmental instability)
|
|
in DISI, is the lunate concavity facing dorsally or volarly?
|
dorsally
|
|
in VISI, is the lunate concavity facing dorsally or volarly?
|
volarly
|
|
what is the normal loading pattern for the wrist?
|
82% born by radius
18% born by ulna |
|
this results from a lengthened ulna
|
positive ulnar variance
|
|
this results from a shortened ulna
|
negative ulnar variance
|
|
what are two things that can increase positive ulnar variance (make ulna longer)?
|
(1) forearm pronation
(2) strong grip |
|
during static activities, what are the two positions of the wrist?
|
(1) 20-30º extension
(2) slight UD |
|
this muscle at the wrist flexes and radially deviates, and also assists with elbow flexion and forearm pronation
|
flexor carpi radialis
|
|
what muscle of the wrist contracts during RD to counterbalance the extensor component of the ECRL?
|
FCR
|
|
what type of muscle is the FCR?
|
fusiform
|
|
what nerve innervates the FCR?
|
median
|
|
a weakness of what muscle may cause a decrease in forearm pronation and wrist flexor strength?
|
FCR
|
|
this muscle of the wrist flexes and UD the wrist, and assits in elbow flexion
|
flexor carpi ulnaris
|
|
this muscle powers activities such as axing, power stroke, karate chop, dart throwing
|
FCU
|
|
what nerve innervates the FCU?
|
ulnar
|
|
this muscle is a pure wrist flexor that tenses the palmar fascia and assists in elbow flexion
|
palmaris longus
|
|
during active finger extension, what muscles stabilize to prevent excessive wrist extension?
|
wrist flexors
|
|
what are five muscles that assist in wrist flexion?
|
(1) FDS
(2) FDP (3) FPL (4) APL (5) EPB |
|
overall, the extensors of the wrist have __% of the strength of the flexors
|
50%
|
|
this muscle extends and radially deviates the wrist; it is the main RD
|
ECRL
|
|
what muscle is most active as a synergist for fist making or prehension?
|
ECRL
|
|
what muscle is named as a wrist extensor, but has a larger moment arm for elbow flexion and RD of the wrist?
|
ECRL
|
|
the ECRL is most effective as a wrist extensor with the elbow in what position?
|
extended
|
|
this extrinsic muscle of the wrist solely extends the wrist
|
ECRB
|
|
this muscle extends and UD the wrist
|
ECU
|
|
the ECU is a better wrist extensor with the forearm in what position?
|
supination
|
|
what muscle is a stabilizer of the wrist during thumb abduction?
|
ECU
|
|
this muscle works synchronously with the ECRL and ED during wrist extension
|
ECU
|
|
what mucsle's tendon helps stabilize the head of the ulna?
|
ECU
|
|
what nerve innervates the ECU, ECRL, and ECRB?
|
radial
|
|
what are four muscles that assist wrist extension?
|
(1) ED
(2) EDM (3) EI (4) EPL |
|
the ED assists wrist extension if the fist is in what position?
|
clenched
|
|
injury to this nerve results in wrist flexion during active finger flexion
|
radial
|
|
efficiency of the finger flexors with the wrist flexed is only __% of that with the wrist extended
|
25%
|
|
what are the seven radial deviators of the wrist?
|
(1) ECRL
(2) ECRB (3) FCR (4) APL (5) EPL (6) EPB (7) FPL |
|
what are the two primary ulnar deviators of the wrist?
|
(1) FCU
(2) ECU |
|
what are three muscles that assist in ulnar deviation of the wrist?
|
(1) FDP
(2) FDS (3) ED |
|
what type of joint is the CMC joint of the thumb?
|
saddle
|
|
how many degrees of freedom are there at the CMC Joint of the thumb?
|
2
|
|
during adduction at the CMC joint of the thumb, what are the directions of roll and slide?
|
posterior roll, anterior glide
|
|
during abduction at the CMC joint of the thumb, what are the directions of roll and slide?
|
anterior roll, posterior glide
|
|
during flexion at the CMC joint of the thumb, what are the directions of the roll and slide?
|
ulnar roll and ulnar glide
|
|
during extension at the CMC joint of the thumb, what are the directions of the roll and slide?
|
posterior roll, posterior glide
|
|
the MC is what shape for thumb CMC ab/adduction?
|
convex
|
|
the MC is what shape for thumb CMC flexion/extension?
|
concave
|
|
in the capsular pattern of the CMC of the thumb, what motion is most limited, and followed by what other motion?
|
abduction most limited, followed by extension
|
|
what is the closepacked position of the thumb CMC joint?
|
full opposition
|
|
what is the resting position of the thumb CMC joint?
|
midway between flex/ext and ab/add
|
|
what are the five ligaments that reinforce the capsule of the CMC joint of the thumb?
|
(1) strong UCL
(2) anterior oblique (3) posterior oblique (4) RCL (5) 1st intermetacarpal |
|
what three movements cause the anterior oblique ligament of the CMC joint of the thumb to be taut?
|
(1) abduction
(2) extension (3) opposition |
|
what three movements cause the ulnar collateral ligament of the CMC joint of the thumb to be taut?
|
(1) abduction
(2) extension (3) opposition |
|
what two movements cause the 1st intermetacarpal ligament of the CMC joint of the thumb to become taut?
|
(1) abduction
(2) opposition |
|
what two movements cause the posterior oblique ligament of the CMC joint of the thumb to be taut?
|
(1) abduction
(2) opposition |
|
what movements cause the radial collateral ligament of the CMC joint of the thumb to be taut?
|
all movements to varying degrees, except extension
|
|
when the thumb is used in these two positions, the ligaments of the CMC joint of the thumb need the assistance of the balanced forces from the muscles to maintain optimal joint alignment
|
adduction and flexion
|
|
what range of thumb CMC flexion is available?
|
45-50º
|
|
what range of thumb CMC extension is available?
|
10-15º
|
|
what range of thumb CMC abduction is available?
|
45º (from the palm)
|
|
what range of thumb CMC adduction is available?
|
to palm of hand
|
|
thumb CMC opposition is a combination of what three movements?
|
(1) abduction
(2) medial rotation (3) flexion |
|
what type of joints are the 2nd and 3rd CMC joints?
|
plane
|
|
what are the articulating bones that form the 2nd and 3rd CMC joints?
|
trapezium, trapezoid and capitate articulate with the base of the 2nd and 3rd metacarpals
|
|
what is usually the only motion allowed at the 2nd and 3rd CMC joints?
|
gliding
|
|
what type of joint is the 4th CMC Joint?
|
plane
|
|
what type of joint is the 5th CMC joint?
|
saddle/pseudosaddle
|
|
what are the articulating bones that form the 4th and 5th CMC joints?
|
hamate and capitate articulate with the bases of the 4th and 5th MCs
|
|
how much flexion/extension ROM is allowed at the 4th CMC?
|
20º
|
|
how much flexion/extension ROM is allowed at the 5th CMC?
|
28º
|
|
what type of joint are the intermetacarpal joints?
|
irregular or plane
|
|
what are the articulating surfaces of the intermetacarpal joints?
|
between 2nd-5th MC bases
|
|
what movement is allowed at the intermetacarpal joints?
|
sliding (helps with hand cupping)
|
|
what side of the hand does more sliding occur at the intermetacarpal joints?
|
ulnar
|
|
what type of joint are the 2nd-5th MP joints?
|
condyloid, biaxial
|
|
at the MP joints of the 2-5th fingers, what shape is the MC head?
|
convex
|
|
at the MP joints of the 2-5th fingers, what shape is the proximal phalanx surface?
|
concave
|
|
where is the axis of motion of the 2-5th MP joints?
|
through the head of the MCq
|
|
this is a thick, dense fibrocartilaginous plate on the palmar surface of the joint between the collateral ligaments
|
volar plate
|
|
what movement does the volar plate prevent?
|
hyperextension
|
|
the thickness of the volar plate increases the moment arm for what tendons by increasing the distane between the tendon and the joint axis?
|
finger flexor tendons
|
|
these are strong rounded cords along the sides of the joints of the fingers
|
collateral ligaments
|
|
what positions are the upper collateral ligaments of the 2-5th fingers taut and slack in?
|
slack in extension (allowing finger ab/add) and taut in flexion (stability for grip)
|
|
what positions are the accessory collateral ligaments of the 2-5th fingers taut and slack in?
|
taut in extension, and slack in flexion
|
|
these ligaments are wide bands that connect the volar plates of the 2-5th MP joints, and they limit abduction of the metacarpals
|
deep transverse metacarpal ligament
|
|
what positions are the deep transverse metacarpal ligaments taut and slack in?
|
slack in adduction, taut in abduction
|
|
what muscles are located anterior to the deep transverse MC ligament?
|
lumbricales
|
|
what muscles are located posterior to the deep transverse MC ligament?
|
interossei
|
|
what ligament of the hand helps to preserve the MC arch?
|
deep transverse metacarpal ligament
|
|
the capsule at what joint of the finger is the loosest?
|
MP
|
|
what is the close packed position of the hand?
|
MP flexed, IPs extended
|
|
what range of flexion is allowed at the 2-5th MP joints?
|
90º (increases at pinky)
|
|
what range of extension is allowed at the 2-5th MP joints?
|
+10-20º actively
|
|
what range of radial deviation is allowed at the 2-5th MP joints?
|
9-19º
|
|
what range of ulnar deviation is allowed at the 2-5th MP joints?
|
20-43º
|
|
what are the directions of the roll and glide at the 2-5th MP joints during flexion?
|
anterior roll, anterior glide
|
|
what are the directions of the roll and glide at the 2-5th MP joints during extension?
|
posterior roll, posterior glide
|
|
what carpal bones do the fingers orient toward when flexed (with NORMAL MP joint motion)?
|
scaphoid
|
|
is there a tighter grip on the radial or ulnar side of the hand?
|
ulnar
|
|
what type of joint is the MP of the thumb?
|
condyloid
|
|
how many degrees of freedom are there at the MP joint of the thumb?
|
2
|
|
what is the closepacked position of the thumb MP joint?
|
flexion
|
|
what ligament is more easily stretched/injured at the thumb MP joint, RCL or UCL?
|
UCL
|
|
this injury is a stretch of the thumb UCL
|
Gamekeeper's thumb
|
|
what two tendons on the palmar side of the MP joint of the thumb contain sesamoid bones?
|
(1) flexor pollicis brevis
(2) adductor pollicis |
|
what range of flexion is allowed at the thumb MP joint?
|
45-90º
|
|
what range of extension is allowed at the thumb MP joint?
|
0º
|
|
what type of joints are the IP joints at the fingers?
|
hinge/uniaxial
|
|
what is the shape of the proximal segment at the IP joints of the fingers?
|
convex
|
|
what is the shape of the distal segment at the IP joints of the fingers?
|
concave
|
|
at the IP joints, when are the collateral ligaments taut?
|
remain taut throughout range because of broad transverse dimension of head of proximal phalanx
|
|
what positions are the accessory collateral ligaments of the IP joints of the fingers taut and slack in?
|
slack in flexion, taut in extension (like volar plate)
|
|
at the MP joints of the 2-5th fingers, which collateral ligaments are longer, contributing to increased ulnar deviation?
|
radial collateral
|
|
what range of flexion is allowed at the PIP joint of the fingers?
|
100-120º
|
|
what range of flexion is allowed at the DIP joint of the fingers?
|
70-90º
|
|
what range of extension is allowed at the IP joints of the fingers?
|
0º actively (DIP can get more passively)
|
|
what is the range of flexion allowed at the thumb IP joint?
|
70º
|
|
what is the range of extension allowed at the thumb IP joint (passively)?
|
20º (increases throughout life)
|
|
what is the most stable arch of the hand (located at the level of the carpal tunnel)?
|
tranverse carpal arch
|
|
what is the keystone of the transverse carpal arch of the hand?
|
capitate
|
|
this arch of the hand is formed by the MCs and phalanges; stability of the MP joints and volar plates are essential to preserve this arch
|
longitudinal arch
|
|
what are the five extrinsic muscles of the fingers?
|
(1) ED
(2) EI (3) EDM (4) FDP (5) FDS |
|
this muscle extends the MP joints of the fingers via attachment into sagittal bands, and assists with IP extension of MPs are not fully extended; assists in abduction of fingers and with wrist extension and RD
|
extensor digitorum
|
|
if the ED muscle is unopposed, what would occur at the fingers?
|
MP joints hyperextended (claw)
|
|
what is the only muscle that extends the MP joints of the fingers?
|
ED
|
|
what muscle is active during making a fist to slow down MP flexion so the FDP and FDS can flex the IP joints before using up their excursion?
|
ED
|
|
what two positions of the hand would indicate shortness of the ED?
|
(1) hyperextension of MPs if wrist flexed
(2) extension of wrist if MPs flexed |
|
this muscle extends the index finger MP joint and assists with IP extension and adduction of the index finger
|
EI
|
|
this muscle extends the 5th MP joint, assists in IP extension and abduction of the 5th finger
|
EDM
|
|
this muscle flexes the DIP of fingers, assists in flexion of PIP, MP, CMC, and wrist; assists in adduction
|
FDP
|
|
this arch of the hand is formed by the MCs and phalanges; stability of the MP joints and volar plates are essential to preserve this arch
|
longitudinal arch
|
|
what are the five extrinsic muscles of the fingers?
|
(1) ED
(2) EI (3) EDM (4) FDP (5) FDS |
|
this muscle extends the MP joints of the fingers via attachment into sagittal bands, and assists with IP extension of MPs are not fully extended; assists in abduction of fingers and with wrist extension and RD
|
extensor digitorum
|
|
if the ED muscle is unopposed, what would occur at the fingers?
|
MP joints hyperextended (claw)
|
|
what is the only muscle that extends the MP joints of the fingers?
|
ED
|
|
what muscle is active during making a fist to slow down MP flexion so the FDP and FDS can flex the IP joints before using up their excursion?
|
ED
|
|
what two positions of the hand would indicate shortness of the ED?
|
(1) hyperextension of MPs if wrist flexed
(2) extension of wrist if MPs flexed |
|
this muscle extends the index finger MP joint and assists with IP extension and adduction of the index finger
|
EI
|
|
this muscle extends the 5th MP joint, assists in IP extension and abduction of the 5th finger
|
EDM
|
|
this muscle flexes the DIP of fingers, assists in flexion of PIP, MP, CMC, and wrist; assists in adduction
|
FDP
|
|
which muscle has a larger moment arm at the PIP, FDP or FDS?
|
FDP
|
|
which muscle has a larger moment arm at the wrist and MP, FDP or FDS?
|
FDS
|
|
which finger flexor is more active during light finger flexion?
|
FDP
|
|
which finger flexor contributes more to finger flexion when there is a load placed?
|
FDS
|
|
what is the only muscle that flexes the DIP joints of the fingers?
|
FDP
|
|
what two positions will the hand be in if there is shortness of the FDP?
|
(1) flexion of fingers if wrist extended
(2) flexion of wrist if fingers extended |
|
which finger flexor muscle needs stabilization of all other fingers during the MMT?
|
FDS (becasue you prevent FDP from working on tested finger because FDP is connected)
|
|
this muscle flexes the PIP of fingers, assists in MP, CMC, and wrist flexion
|
FDS
|
|
this muscle functions alone only when DIP flexion of the fingers is not required
|
FDS
|
|
this muscle powers the most individual finger motion
|
FDS
|
|
what would be the presentation of a contracture of the FDP muscle?
|
flexion deformity of DIP joints
|
|
what would be the presentation of a contracture of the FDS muscle?
|
flexion deformity of the PIP joints
|
|
what two positions would the hand be in if the FDS was short?
|
(1) flexion of PIP if wrist extended
(2) flexion of wrist if PIPs extended |
|
for tendon gliding, during a straight fist, what muscle glides maximally with respect to the sheath and bone?
|
FDS
|
|
for tendon gliding, during a hook fist, there is maximum gliding between what structures?
|
the tendons of the FDS and FDP
|
|
for tendon gliding, during a regular fist, there is maximum gliding of what muscle with respect to the sheath and bone?
|
FDP
|
|
if there is no counterbalancing extensor force at the wrist, then when the finger flexors contract, what will they cause the wrist to do?
|
flex
|
|
what are the four extrinsic muscles of the thumb?
|
(1) APL
(2) EPB (3) EPL (4) FPL |
|
this muscle abducts and extends the CMC joint of the thumb, and assists in RD and flexion at the wrist
|
abductor pollicis longus
|
|
what muscle maintains the arch of hte pinch by preventing collapse of the thumb MC under the influence of adductors?
|
APL
|
|
what would a contracture of the APL muscle present as?
|
abducted and slightly extended position of 1st MC with slight RD of wrist
|
|
what muscle is found in the 1st extensor compartment of the wrist?
|
APL
|
|
to test the length of the APL, what would you do?
|
flex thumb, UD wrist, and slightly extend wrist
|
|
this muscle extends the thumb MP joint, extends and abducts CMC of thumb, assists in RD and flexion of the wrist
|
EPB
|
|
weakness of what thumb muscle decreases the ability to extend the thumb MP joint and may result in a position of thumb MP flexion?
|
EPB
|
|
this muscle extends the IP joint of the thumb, assists in thumb MP and CMC extension, and assists in RD and extension of the wrist
|
EPL
|
|
at the thumb CMC joint, what muscle is an extensor and adductor
|
EPL
|
|
to test the integrity of this muscle, you would see if someone could lift their thumb off the table
|
EPL
|
|
if the thumb adducts as the person is extending it, what muscle is working too much and what is not working enough?
|
EPL too much, APL not enough
|
|
this muscle flexes the IP joint of the thumb and assists in flexion of the MP, CMC of the thumb and may assist in wrist flexion
|
FPL
|
|
if there is marked weakness of this muscle, you may develop a hyperextension deformity of the IP joint of the thumb
|
FPL
|
|
what is the only thumb IP joint flexor?
|
FPL
|
|
to test the length of the FPL, what would you do?
|
(1) extend thumb
(2) extend wrist (3) slight UD if short, IP joint will flex |
|
this muscle abducts the 5th MP and assists in opposition of CMC and flexion of 5th MP; may assist in IP extension of 5th due to small insertion into extensor expansion
|
ADM
|
|
in normal hand cupping, the ADM contraction is accompanied by contraction of what other muscle in order to stabilize the pisiform bone?
|
FCU
|
|
this muscle flexes the MP of the 5th finger and may assist in opposition of CMC of 5th finger
|
FDM
|
|
this muscle flexes and rotates the CMC of the 5th finger
|
opponens digiti minimi
|
|
a weakness in this muscle causes flattening of the palm (makes it difficult to oppose little finger)
|
ODM
|
|
this muscle abducts index, middle, and ring finger, assists in flexion of MPs and extension of IPs
|
dorsal interossei
|
|
this muscle may assist in adduction of the thumb
|
1st dorsal interosseous
|
|
what intrinsic hand muscles are active in power grip?
|
dorsal interossei
|
|
what shape are the dorsal interossei muscles?
|
bipennate
|
|
which muscle has 4x as much force as the lumbricales?
|
dorsal interossei
|
|
are the dorsal interossei volar or dorsal to the axis of motion at the MP joints of the fingers?
|
volar
|
|
are the dorsal interossei volar or dorsal to the axis of motion at the IP joints of the fingers?
|
dorsal
|
|
the moment arm for flexion for the dorsal interossei increases as the MP does what motion?
|
flexes
|
|
the angle of pull of this muscle is such that it would stabilize the base of the 1st MC from dorsoradial subluxation
|
1st dorsal interosseous
|
|
these muscle adduct the thumb, index, ring, and small fingers; assists in MP flexion and IP extension, and are unipennate
|
palmar interossei
|
|
what shape are the palmar interossei muscles?
|
unipennate
|
|
what position would you put the hand in to test the length of the interossei muscles?
|
flex IPs, extend MPs
|
|
these muscles extend IPs and simultaneously flex MPs of finger, and extend the IPs with the MPS extended
|
lumbricales
|
|
these muscles are rich in sensory organs to balance flexor and extensor tension; and suppress flexor tension to correct clawing
|
lumbricales
|
|
what side of the finger are the lumbricales located on?
|
radial side
|
|
what muscles in the hand have a longer excursion and are farther fro the joint axis than the interossei, but don't produce as much force because the interossei have more fibers?
|
lumbricales
|
|
this muscle pulls the extensor mechanism proximally, which increases tension in the extensor hood
|
lumbricales
|
|
this muscle abducts the CMC and MP at the thumb, and assists in thumb IP extension
|
APB
|
|
what would weakness of the APB cause?
|
difficulty grasping large objects due ot difficult abducting thumb
|
|
this muscle flexes both the MP and CMC joints of the thumb, and assists in IP extension and opposition
|
FPB
|
|
what would a contracture of the FPB muscle present as?
|
flexion deformity of MP joint of thumb
|
|
this muscle opposes the MC joint of the thumb, rotates the thumb into pronation
|
opponens pollicis
|
|
what would a weakness of the opponens pollicis present as?
|
flattening of thenar emminence and difficulty holding a pencil for writing or grasping objects firmly between thumb and fingers
|
|
this muscle adducts the CMC joint of the thumb, adducts and assists flexion of MP of thumb, and assists thumb IP extension
|
adductor pollicis
|
|
what nerve innervates the adductor pollicis?
|
ulnar nerve
|
|
what muscle has the best torque potential of any other thumb CMC muscle?
|
adductor pollicis
|
|
most commonly during function, the thumb is in what two positions?
|
adduction and flexion
|
|
what are five forces that contribute to alteration in the mechanical forces at the CMC Joint of the thumb?
|
(1) adduction and flexion during function
(2) insufficient function of APL, APB, 1st DI to stabilize CMC (3) shortness and overuse of MP flexors and adductor of thumb (4) weak EPB (5) ligament laxity |
|
the MP extension at the fingers occurs via what structure in the extensor mechanism?
|
sagittal bands
|
|
PIP extension at the fingers occurs via what structure in the extensor mechanism?
|
central slip
|
|
DIP extension at the fingers occurs via what structure in the extensor mechanism?
|
terminal tendon
|
|
what are the five components of the extensor mechanism (muscles)?
|
(1) ED
(2) EI (3) EDM (4) lumbricales (5) interossei |
|
this part of the extensor mechanism attaches at the base of the middle phalanx
|
central slip
|
|
this part of the extensor mechanism attaches at the base of the distal phalanx
|
terminal tendon
|
|
normally, the lateral bands of the extensor mechanism are volar or dorsal to the PIP and DIP joints at the fingers?
|
dorsal
|
|
this deformity of the hand occurs when the central slip of the extensor mechanism is avulsed, causing DIP hyperextension and PIP flexion (because lateral bands slip volarly)
|
Boutonneire deformity
|
|
shortness of what ligament of the finger contributes to a Boutonneire deformity?
|
oblique retinacular ligament
|
|
this deformity is when the volar plate is too lax and the interossei are short, causing MP flexion, PIP hyperextension, and DIP flexion
|
swan neck deformity
|
|
this deformity occurs from rupture of the terminal tendon of the extensor mechanism, causing a loss of active DIP extension
|
mallet finger
|
|
in a mallet finger deformity, the extensor mechanism may retract, causing increasing tension on the central slip and creating a secondary deformity of what type?
|
swan neck (PIP hyperextension)
|
|
this deformity occurs when there is a loss of intrinsic muscle stabilization; the ED is no longer balanced by the intrinsics resulting in MP hyperextension and IP flexion (Because ED cannot extend IP joints)
|
clawing
|
|
a clawhand deformity can occur due to what nerve injury?
|
ulnar
|
|
during an ulnar nerve injury, which fingers claw the worst since they are solely innervated by the ulnar nerve?
|
4th and 5th
|
|
this apparatus prevents bowstringing of the flexor tendons
|
flexor apparatus
|
|
how many annular and cruciate pulleys are there in the flexor apparatus of the fingers?
|
4 annular, 3 cruciate
|
|
what are the two most important pulleys in the flexor apparatus of the fingers?
|
A2 and A4
|
|
this is when the flexor tendons relatively lengthen with respect to the skeleton, decreasing their efficiency and not allowing you to make a full fist
|
bowstringing
|
|
the flexor tendons of the fingers cross the MP joint at what type of angle?
|
ulnar angle
|
|
these finger flexor tendons insert on the distal phalanx
|
FDP
|
|
these finger flexor tendons insert by two slips at the base of the middle phalanx
|
FDS
|
|
how do you stretch the oblique retinacular ligament of hte finger?
|
simultaneously extend PIP and flex DIP
|
|
what is the normal sequence of finger flexion?
|
PIP then MP then DIP
|
|
what is the normal sequence of finger extension?
|
MP then DIP then PIP
|
|
if there is a short arc of motion for finger flexion, what muscle is not working?
|
interossei
|
|
Froment's sign is a quick test for injury to this nerve; a person grasps a piece of paper, and their IP joint flexes instead of staying in extension
|
ulnar
|
|
in Froment's sign, when the IP flexes, what muscle is working too much and what is working too little?
|
FPL too much, adductor pollicis too little
|
|
an injury to what nerve would cause loss of the FDP, causing inability to actively flex DIP and MP joints of small and ring fingers?
|
ulnar
|
|
an injury to what nerve would cause atrophy of the hypothenar muscles?
|
ulnar
|
|
an injury to what nerve would cause loss of power grip and a poor pinch grip?
|
ulnar
|
|
an injury to what nerve would cause atrophy of the thenar emminence?
|
median
|
|
an injury to this nerve would result in inability to flex DIP and PIP joints of index and middle fingers and weak PIP flexion of ring and small
|
median
|
|
an injury to what nerve would cause loss of abduction and opposition of the thumb?
|
median
|
|
an injury to what nerve owuld cause loss of the lumbricales, causing inability to completely actively extend IP joints of middle and index fingers?
|
median
|
|
an injury to what nerve would cause a loss in wrist flexion and pronation strength?
|
median
|
|
an injury to what nerve presents with wrist drop?
|
radial
|
|
what is a quick test for the integrity of the radial nerve?
|
ask someone to extend fingers; will only extend at IPs, not MCP
|
|
an injury to what nerve would cause a loss of wrist, finger, and thumb extensors?
|
radial
|
|
an injury to what nerve would cause active insufficiency of finger flexors due to loss of wrist extensors?
|
radial
|
|
an injury to what nerve would cause a flexion posture of the thumb?
|
radial
|
|
what muscle is active during the three jaw chuck pinch?
|
opponens pollicis
|
|
what muscle is active during the key pinch (and is the strongest pinch)?
|
adductor pollicis
|
|
what muscle is active during tip to tip pinch?
|
flexor pollicis longus
|
|
what force results at the elbow during resisted shoulder medial rotation?
|
valgus
|
|
if there is a positive ulnar variance at the wrist, are there higher or lower compressive forces at the joint?
|
higher
|
|
what kind of stress is placed at the volar plate of the PIP joint with a swan neck deformity?
|
tension
|
|
what thenar muscles are active during a gentle grasp (opposition of thumb with any of the other fingers)?
|
opponens pollicis predominates
APB>FPB |
|
what thenar muscles are active with firm opposition of thumb to the index or middle finger?
|
FPB>Opponens
AdPollicis>AbPB |
|
what thenar muscles are active with firm opposition of the thumb to the ring finger?
|
Opponens increases but still AbPB increases but still
|
|
what thenar muscles are active with firm opposition of the thumb to the small finger?
|
opponens=FPB
abductor pollicis brevis=adductor pollicis |
|
this is the type of grip one has when holding a tennis racket
|
cylindrical grip
|
|
this is the type of grip one has when holding a baseball
|
spherical grip
|
|
this is the type of grip one has when holding a brief case handle
|
hook grip
|
|
this is the type of grip one has when holding a cigarette
|
lateral prehension
|
|
what are the four types of power grips?
|
(1) cylindrical
(2) spherical (3) hook (4) lateral prehension |
|
this is the type of grip someone has when holding a quarter
|
pad to pad prehension
|
|
this is the type of grip someone has when holding a straight pin
|
tip to tip prehension
|
|
this is the type of grip someone has when pinching a key
|
pad to side prehension
|
|
what are the three types of precision handling grips?
|
(1) pad to pad prehension
(2) tip to tip prehension (3) pad to side prehension |
|
in the cylindrical grip, what finger flexor is active in the dynamic phase?
|
FDP
|
|
in the cylindrical grip, what finger flexor is active in the static phase?
|
FDS
|
|
in the cylindrical grip, what muscles are active and function as MP flexors, abductors, and adductors?
|
interossei
|
|
in the cylindrical grip, what finger intrinsics are relatively silent?
|
lumbricales
|
|
in the power grip, what muscle acts as a stabilizer to increase joint stability and compression?
|
ED
|
|
are the thenar muscles active during cylindrical grip?
|
yes (FPL and thenar muscles all active)
|
|
a distinguishing characteristic between power grip and precision handling is that what muscle is very active in power grip?
|
adductor pollicis
|
|
are the hypothenar muscles active in cylindrical grip?
|
yes
|
|
the main difference in this grip from the cylindrical grip is that the finger spread leads to increased interosseous activity
|
spherical grip
|
|
what is the major muscle activity during a hook grip?
|
FDP and FDS (some interosseous)
|
|
does a hook grip ever include the thumb?
|
NO, may include palm
|
|
during lateral prehension, what is the position of the MP and IP joints?
|
extension, MP simultaneously abducted or adducted
|
|
during lateral prehension, these muscles help extend the fingers
|
lumbricales, ED
|
|
during lateral prehension, these muscles help ab/adduct the fingers
|
interossei
|
|
what type of muscular activity occurs during precision handling?
|
isotonic
|
|
what type of fine grip accounts for about 80% of precision handling?
|
pad to pad prehension
|
|
what muscle is used if the DIP is flexed in a grip?
|
FDP
|
|
what muscle is used if the DIP is extended in a grip?
|
FDS
|
|
what muscles supplement MP flexion force and ab and adduction at the MP joints during a grip?
|
interossei
|
|
the activity of what muscle increases with the pressure of the pinch?
|
adductor pollicis
|
|
what muscle controls IP flexion of the thumb during a grip?
|
FPL
|
|
what is the most precise form of grasp?
|
tip to tip prehension
|
|
what is the difference between pad to pad and tip to tip prehension?
|
need full IP joint flexion, and MP must ulnarly deviate
|
|
what three muscles are used during tip to tip prehension?
|
FDP, FPL, interossei
|
|
what 7 muscles are used during pad to pad prehension?
|
(1) FDP if DIP flexed
(2) FDS if DIP extended (3) interossei (4) opponens pollicis (5) FPB (6) APB (7) adductor pollicis |
|
what is the least precise form of pinch?
|
pad to side prehension
|
|
what is the difference between pad to side prehension and other forms of prehension?
|
thumb more adducted and less rotated
|
|
during pad to side prehension, the activity of what muscles increases?
|
FPB, adductor pollicis
|
|
during pad to side prehension, the activity of what muscle decreases?
|
opponens
|
|
what type of grip can be performed using tenodesis with paralysis of the hand muscles by extending the wrist?
|
pad to side prehension
|