Hand packet 2 Flashcards
flexor surface of the hand consists of a ____ mechanism & a _____ system
gliding;
pulley;
flexor surface contains (anatomy)
flexor retinaculum
bursae
flexor tendon sheath
ligaments
flexor retinaculum prevents
bowstringing of flexor tendons of the wrist
flexor retinaculum is a ________ _______ ligament
transverse carpal
bursae decreases _____ between ____ & ______
friction;
flexor tendons; & retinaculum
bursae has a _____-like sheath and serves as a _____
synovial;
lubricant;
bursae of the hand begins at the distal
radius/ulna
ulna bursae location
- ends just distal to proximal crease
- continues up 5th digit
radial bursa consists of
Flexor pollicis longus
ulna bursa consists of
FDS & FDP
digital flexor tendon sheath function
- envelope tendons
- synovial-like
digital flexor tendon sheath begins
just proximal to the 1st annular pulley and ends at FDS split
purpose of the anatomical pulleys of the fingers
- hold the tendons & sheath to phalanges
- prevents bowstringing of tendons
- minimizes stress/pressure between tendon & sheath
- promotes gliding
how many annular pulleys?
5
how many cruciform pulleys?
3
A1 is located at the
MC Head
A2 location
base of proximal phalanx
A3 location
Head of the proximal phalanx
A4 location
Middle of the middle phalanx
A5 location
over DIP
C1 location
middle of proximal phalanx
C2 location
base of middle phalanx
C3 location
head of middle phalanx
extensor mechanisms of the fingers
- Extensor Digitorum
- Extensor expansion/extensor hood/dorsal aponeurosis
- dorsal & volar interossei
- lumbricals
As the extensor digitorum progression:
5 STEPS
1) under extensor retinaculum (synovial sheath)
2) loses sheath distal to the retinaculum
3) then, distal to MCP the ED tendons flatten leading to a dorsal aponeurosis (DA)
4) DA is joined by interossei tendons (prox wing tendon)
5) DA trifurcates just proximal to the PIP
central tendon of the distal aponeurosis goes to
base of the middle phalanx
two lateral bands of the distal aponeurosis go to
form a single terminal tendon, which goes to the base of the distal phalanx
Two lateral bands of the distal aponeurosis receive contributions from:
- interossei
- lumbricals
- lateral brachi (send slip to terminal tendon)
lumbricals fall on the _____ side of the joint
radial
lateral brachi receives
ORL (oblique retinacular ligament)
extension mechanism
ORL arises from the sides of _____ & ______
1st phalanx;
digital tendon sheaths
(extension mechanism)
triangular ligament/transverse retinaculum consist of
lateral bands interconnected dorsally
help with extension
dorsal hood attached to the _____ metacarpal ligament prevents
transverse;
bowstringing
(help with extension)
transverse metacarpal ligament connects
heads of all of the ligaments
MCP joints extend because ______ tendon is dorsal to _______
this causes the pull of the ______ proximally
extensor digitorum;
joint AOR;
hood
MCP will extend regardless if lumbricals and/or interossei fire…. why????
because extensor digitorum is stronger than those intrinsic muscles
extensor digitorum (central tendon) can extend ____ but not ____
PIP;
alone
if there is an isolated extensor digitorum then the outcome of this is _____
clawing
lumbricles and interossei produce ____ to the central tendon/lateral bands through the _____. This causes _____ extension.
tension;
ORL;
PIP
lumbrical grip
ex: reading a newspaper
- flex MCPs
- extend IPs
DIP & PIP are _____.
Ex: With active DIP _____ you get active PIP _____
interdependent; extension; extension; OR flexion; flexion;
Active intrinsics on the lateral bands/terminal tendons causes:
passive stretching of ORL and DIP extension
Intrinsic hand (-)
MCP hyperextension with IP flexion
claw hand
active or passive PIP full flexion prevents:
active DIP extension
Dorsal interossei do what movement
abduct
dorsal interossei _____ MCP when MCP is _____
2 ANSWERS!!!
abduct; extended;
OR
flex; flexed
Dorsal Interossei allow for the IP extension of what digits
2nd, 3rd & 4th
how does the 5th digit get abducted? (what muscle)
abductor digiti minimi
Palmar interossei are responsible for what movement
adduction
palmar interossei _______ MCP when MPC is _____
2 ANSWERS!!!
adduct; extended;
OR
flex; flexed
Palmer interossei allow for the IP extension of what digits?
2nd, 4th, 5th
not the middle finger
why do the palmer interossei have no effected on the middle finger (digit 3)???
b/c adduction isn’t needed
all of the fingers go to the middle finger during adduction
Lumbricals origin
tendon of FDP
lumbricals insertion
radial side of the distal lateral bands of EM
lumbricals attachment to the _______ allow for effective ________
distal lateral bands; IP extension
lumbricals can _____ MCP but weaker than ______
flex;
interossei
function of lumbricales is dependent on function of the FDP & ED because:
lumbricales attach to FDP & ED tendons – therefore if those muscles are lax than the lumbricles will be wayyy less efficient
The FDP can close hand without other musculature, however without _____, there will be uncoordinated finger _____, causing a _________
intrinsics;
flexion;
ineffective grasp;
AKA INTRINSIC NEGATIVE (-) HAND
Thumb DOF
2-3 DOF –
flexion/extension
abduction/adduction
axial rotation???
type of joint of the thumb CMC
saddle joint
articulations of the thumb CMC
trapezium & base of 1st metacarpal
thumb opposition is the coupled motion
abduction –> flexion –> adduction & rotation
1st CMC joint structure
lax joint capsule with radial, ulnar, velar, & dorsal ligaments
1st CMC joint has slips of ______ ligaments to support it volarly & dorsally
intercarpal
IP joint of the thumb is what kind of joint
hinge
thumb is controlled by more muscles than digits _____
2-4
how many muscles control the thumb?
8
____#____ extrinsic muscles in the thumb & the names
4
- FPL (volar)
- EPL, APL, & EPB (dorsolaterally – snuff box)
___#_____ intrinsic muscles in the thumb & names
4
- OP
- FPB - 2 heads
- ADP
- APB
power grasp 3 types
cylindrical
spherical/ball
hook
power grasp occurs when:
- fingers clamp object into palm
- fingers in sustained flexion
- palm conforms to object
- thumb may or may not contribute to this
cylindrical power grasp
- fingers surrounds object with counterforce from thenar eminence &/or thumb
spherical/ball power grasp
- fingers surrounds object with counterforce from thenar eminence &/or thumb (SAME AS CYLINDRICAL)
- however, there is a GREATER spread of fingers evoking more interossei activity
hook power grasp
no opposition of thumb,
ex: carrying a brief case
precision handling types
1) tip to tip pinch
2) pad to pad/palmer pinch
3) pad to side/lateral/key
4) 3-jaw chunk/tripod
precision handling definition
objects pinched or manipulated between fingers & thumb
functional ROM for slight wrist extension
20-30 degrees
functional ROM for slight ulnar deviation
10 deg
functional ROM for MCP flexion
45 deg
functional ROM for PIP flexion
30 deg
functional ROM for DIP flexion
just a slight flexion is k
mallet finger
distal terminal tendon rupture of extensor digitorum
it causes flexion of the DIP
boutonniere (button hole) finger
disease of the tendon in which the central slip is thinning
this causes the lateral bands to dislocate,
causing flexion of PIP & hyperextension of DIP
swan neck finger
spasm & contracture of intrinsics which attaches to lateral bands
- causes a laxity or rupture of the palmer plate (this normally prevents hyperextension)
- lateral bands then dislocate dorsally
- this causes hyperextension of PIP and flexion of PIP
swan neck finger occurs in ___% of __________ patients
28%
rheumetoid arthritis
