”Intrinsic muscles of the hand: an overvieuw.”
Et Referat av IFSHT kongress
en appetitt vekker til høstseminaret!!!
Sydney 11-15 mars 2007
8 Mars tok jeg fly til Stockholm og samme med tre Svensker fløy jeg videre til Sydney. Det
var en lang reise som gikk overraskende bra. Vi var der en dag i forkant av the council
meeting og den dagen trengte vi så absolutt for en tidsforskjell på 11 timer er ikke bare bare!!
Det var sen sommer i Sydney og det var varm, veldig varm. Og solen stekte ubønnhørlig, noe
som to av de svenske, som hadde fri den 11 mars, smertelig fikk erfare. Å legge seg på
stranden uten å bruke solcrème er ikke akkurat veldig smart i Australia. Ai ai de så ikke særlig
bra ut L
Bortsett fra en skikkelig jetlagg var jeg de første dager også litt forvirret av at solen beveger
seg i feil retning. Du skulle ikke tro at det kan være så forvirrende men det ble det faktisk. Jeg
har vart på sørlig halvfronten før men det har ikke forstyrret meg så mye som det gjorde i
Australia. Antagelig fordi jeg var ute etter å sitte i skygge så mye som mulig men den skygge
utviklet seg jo i feil retning slik at jeg bestandig endte opp i solen ;-)
Søndag 11 mars var det den store council meeting hvor jeg representerte Norge som
internasjonal kontakt. Det var en lang og intens møte, som det pleier å være. Referatet av dette
finner du inn min årlige rapport som internasjonal kontakt.
Selve kongressen begynte søndagskveld med en åpenings seremoni som var veldig spesiell
med opptreden av noe aboriginer.
Det deltok 513 terapeuter fra 32 land. Og så var det ca 1500 kirurger. Så det var ikke ett liten
kongress.
Istedenfor å gi ett overfladisk oversikt av det som skjedde gjennom kongressen velger jeg å gå
inn i dybden. Og gi ett referat fra en workshop som jeg deltok på og som henger fint i hopp
med noen av tingene Ton Schreuders kommer til å ta opp på vårt høstseminar. Så egentlig kan
dette referatet bli sett som en appetitt vekker til høstseminaret.
Jeg skal prøve så godt jeg kan å forklare hva Judy Colditz snakket om i sin workshop med
tema
”Intrinsic muscles of the hand: an overvieuw.”
Det var egentlig ikke så mye workshop de var mer en forelesning I en mindre gruppe. Vi satt i
salen og hørte på.
Judy hadde dessverre ikke noe handout og jeg skrev og skrev så jeg fikk kramper. Jeg skal
gjøre mitt beste å gjengi innholdet på workshoppen så godt som mulig men ikke tar alt jeg
skriver for gitt. Jeg kan dessverre ikke garantere at det ikke er smyget inn seg noe feil. Men
hvis det er ett eller annet dere lyrer på så ta det med til høstseminaret og ta det opp med Ton
han er en ekspert på intrinsic muskler han var dessuten også til stedet på Judy sin workshop
og han var heller ikke enig i alt Judy sa. Så det kan bli en fin ”diskusjon” på høstseminaret
hvis dere tar opp de tingene dere lyrer og tviler på.
I løp av dette referatet kommer det bli en liten miks av noen norske og engelske ord. Men det
burde ikke være noe problem for forståeligheten tror jeg. I så fall ta det opp på høstseminaret.
Bildene og al engelsk tekst er tatt fra CD rommen Primal pictures Ineractive hand
Extensor apparatus = dorsal apparatus:
The extensor apparatus is a system of precisely
orientated fibers in a continuum.
The extensor apparatus is also known as the extensor
expansion, the dorsal digital expansion and the extensor
aponeurosis or hood. All of these terms lack precise
boundaries.
Tendinous contributions
The extensor apparatus receives the insertion of four
tendons;
Common extensor tendon (comprising of extensor
digitorum along with extensor indicis, on the index
finger, and extensor digiti minimi, on the little),
Two interossei muscles,
A lumbrical muscle on the radial side.
Fibers of the common extensor tendon course distally
radiating out, proximal to the PIP joint, towards three
tendinous insertions (one middle and two lateral
conjoined extensor tendons).
The interossei (together with a lumbrical on the radial
side of each finger) form the lateral tendons of the
extensor apparatus. These give rise to a radiating fan of
fibers; the transverse, oblique and lateral tendon fibers proper.
Internal components:
Within the apparatus, each tendinous contribution separates to act at the two interphalangeal
joints.
The separation and rejoining of these fibers results in the formation of a number of
components;
- A middle conjoined extensor tendon,
- Two lateral conjoined extensor tendons,
- A terminal conjoined extensor tendon.
Central fibers of the common extensor tendon cross the PIP joint receiving medially radiating
fibers from each lateral tendon to become the middle conjoined extensor tendon. This tendon
inserts dorsally into the base of the middle phalanx.
Lateral fibers of the common extensor tendon pass on either side of the middle conjoined
extensor tendon joining with fibers of the lateral tendons to form two lateral conjoined
extensor tendons.
The lateral conjoined extensor tendons are joined by fibers from Landsmeer's oblique
retinacular ligaments, fusing to form the terminal conjoined extensor tendon. This singular
tendon crosses the dorsal surface of the DIP joint to insert into the base of the distal phalanx.
Retinacular structures
In addition, some fibers joining the apparatus have a purely retinacular (retaining) role;
- Sagittal bands at the MP joint,
- Landsmeer's transverse retinacular ligaments at the PIP joint,
- Landsmeer's oblique retinacular ligament.
The sagittal bands at the MP joint and Landsmeer's transverse retinacular ligaments at the PIP
joint act to prevent lateral displacement of the extensor apparatus.
Landsmeer's oblique retinacular ligament assists in the control of synchronous movement at
the PIP and DIP joints by anchoring the distal part of the extensor apparatus to a fixed point
palmar to the axis of the PIP joint. The effect of this is to allow the distal extensor apparatus
to glide distally as the PIP joint flexes.
When the PIP joint flexes, the lateral conjoined extensor tendons of the extensor apparatus
move laterally under the action of Landsmeer's transverse retinacular ligaments.
Clinical Text
The extensor apparatus of the finger is an intricately balanced blending of the extrinsic and
intrinsic extension forces of the finger. Therefore it is common that injuries to the extensor
apparatus, or injury/tightness of the muscles whose tendons contribute to the extensor
apparatus will alter the balanced motion of the finger.
Imbalance of motion can be caused by:
Avulsion or laceration of part of the extensor apparatus. The common resulting deformities
are:
Mallet Finger
Boutonniere Deformity
Adherence of part of the extensor apparatus.
This is commonly seen following immobilization for an underlying fracture or repaired
tendon laceration. In these cases the tendinous fibers of the extensor mechanism become
adherent to underlying bone and/or overlying skin and cannot glide. Limited glide of the
apparatus then effects the transmission of tension along the system to the more distal joints.
This circumstance often leads to flexion contractures of the PIP joint.
Adherence of the extensor apparatus can also lead to limitation of active flexion at the PIP
joint.
Dorsal eller ekstensor apparatus består av:
- Extensor Digitorum Communis EDC
- Central slip
- Lateral/sagittal bands
This retaining tissue is a fibrous sheet between the common extensor
tendon and lateral aspects of the volar plate of the
metacarpophalangeal joint. As part of the extensor apparatus, it retains
the extensor tendon over the dorsum of the metacarpophalangeal joint
while permitting longitudinal excursion of that tendon due to a bucket
handle type of motion of the sagittal bands.
As the extensor digitorum tendon glides distally, the sagittal band
slackens, allowing flexion of the MP joint. As the common extensor
tendon glides proximally, force is transmitted through the sagittal bands to lift the base of the proximal
phalanx into extension, all the while maintaining the common extensor centrally over the MP joint.
-
Transvers interosseus fibers (MP fleksjon)
The tendons of the interossei on the
ulnar side of the digits and the interossei
and lumbricales on the radial side form a
lateral tendon on each side of the
extensor apparatus. Each lateral tendon
courses distally giving rise to a radiating
fan of fibers; the transverse, oblique and
lateral tendon fibers proper.
Transverse fibers pass dorsally, meeting
the extensor tendon fibers at right angles.
Some of the more superficial transverse
fibers interdigitate with fibers of the
opposite side.
Through the transverse interosseous
fibers the interosseous muscles assist in
stabilizing the extensor digitorum tendon at the metacarpophalangeal joint, performing a function similar to
that of the sagittal bands.
-
Oblique fibers (PIP ekstensjon)
The tendons of the interossei on the
ulnar side of the digits and the interossei
and lumbricales on the radial side form a
lateral tendon on each side of the
extensor apparatus. Each lateral tendon
courses distally giving rise to a radiating
fan of fibers; the transverse, oblique and
lateral tendon fibers proper.
Oblique fibers radiate towards the
midline of the digit merging with fibers
of the middle conjoined extensor tendon.
Some of the more superficial oblique
fibers interdigitate with fibers of the
opposite side.
Through the oblique interosseous fibers the interosseous muscles assist in stabilizing the extensor digitorum
tendon over the proximal phalanx.
-
Conjoined lateral bands
-
Triangular ligament (keeps terminal tendon from spreading too much)
The triangular ligament is formed by flimsy
transverse fibers between the lateral conjoined
extensor tendons over the proximal part of the
middle phalanx.
The fibers continue laterally as the transverse
band of Landsmeer's retinacular ligament.
This ligament is a fascial layer at the dorsum of
the middle phalanx and the middle conjoined
extensor tendon (central slip) which attaches to
the bone at its base. It prevents excessive volar
subluxation of the conjoined lateral bands with
flexion of the middle phalanx.
If the triangular ligament is lacerated or injured,
this is a zone II extensor tendon injury, which
results in a mallet finger deformity.
Transvers retinacular ligament
Landsmeer’s retinacular ligament: transverse
band
This is one of the retaining ligaments of the
extensor apparatus. Its function at the PIP joint is
similar to the sagittal bands at the MP joint,
namely to stabilize the tendinous fibers of the
extensor apparatus on the dorsum of the PIP joint.
This wide ligamentous sheet lies lateral to the
proximal interphalangeal joint and passes from
the lateral margin of the lateral conjoined
extensor tendon to the lateral aspect of the volar
plate and C1 pulley.
When the PIP joint flexes, the lateral conjoined
extensor tendons of the extensor apparatus move
laterally because of Landsmeer's transverse retinacular ligaments.
De Extensor Digitorum Communis EDC:
- Primært en MP ekstensor via de sagitale bånd.
- Sekundær en PIP ekstensor. Den gir bare PIP ekstensjon når MP er ekstendert eller når
MP er blokkert.
- Jobber sammen med intrinsik musculatur.
- Tar opp slark i de dorsal apparatus.
- Kontraktur av EDC gir MP ekstensjon.
Interosseus muscles:
- Primært MP fleksjon og add/abduksjon.
- Sekundært IP ekstesnjon (PIP mer enn DIP)
- Her finnes det veldig store individuelle forskjeller.
- De fyller opp rommet mellom metacarpalene.
- Ødem i hånden påvirker interosseus musklene veldig mye. Ødem begrenser deres
kontraksjons mulighet. (lumbricalene er mindre påvirket av ødem i hånden).
- Interosseus musklene er sterkere enn lumbrikalene.
- Kontraktur i interossei musklene gir IP ekstensjon.
- Dorsal interossei muscles:
The four dorsal interossei abduct the fingers
relative to the midline of the middle finger.
Through their attachments to the extensor
apparatuses they contribute to flexion of the MP
and extension of PIP and DIP joints. They also
have a role in isolated rotation of a digit.
- Volar interossei muscles:
The three volar interossei adduct the fingers relative to the midline of the long finger.
Through their attachments to the extensor apparatuses
they contribute to flexion of the MP and extension of PIP
and DIP joints. They also have a role in isolated rotation
of a digit.
Dette er ganske svake muskler siden de har sin insersjon
på en senestruktur og ikke på en knokkel.
-
Normal finger fleksjon krever interosseus elongation.
Ved en isolert IP ledd skade for eksempel en dislokasjon får man automatisk en
interosseus tightness som resulterer i en redusert finger fleksjon og begrenset MP
ekstensjon.
Dette betyr at man må teste interosseus tightness og dette er forskjellig fra intrinsic
tightness.
Interosseus tightness test:
1. flex MP joint and passive flex the PIP joint and measure the PIP flexion.
2. Passive hyperextend the MP joint and passive flex the PIP joint and measure PIP fexion.
This is a tresshold test: it’s less or not
MEN!!!
Hvor mye MP ekstension skal det være. Det er jo mange som kan overstrekke MP leddene
sine bade aktive og passive. Dette som følge av IMES (Interosseus Muscle Elasticity Score).
Og dette må man ta hensyn til når man skal måle interosseus tightness.
HVORDAN:
Man holder PIP i maksimum fleksjon mens man langsomt bringer MP leddene i passive
ekstensjon. Man går så langt man kan uten å miste den maksimale PIP fleksjonen. Dette er
MP ekstensjonen man skal sette MP leddene i når man skal måle interosseus tightness.
MPº + PIPº = score
I tilfelle av en skadet hånd:
Injuried score
= % of normal IMES
Normal score
Eksempel:
Frisk hånd
PIP 110º
Skadet hånd PIP 70º
8º < 17º
MP 17º
MP 8º
= interosseus thightness
= 127º
= 78º
78
= 59,8% av normal IMES
127
Man kan gå utefra at neste hver skadet hånd har en Interosseus tightness unless the opposite
has been proved.
Treatment to reduce interosseus muscle tightness:
- Det er en forskjell mellom en radial og en ulnar interosseus tightness.
- Radial deviasjon krever lengthening av de ulnare interossei.
- Ulnar deviasjon krever lengthening av de radial interossei.
- De radiale interossei tillater mer lengthening enn de ulnare. Vi kan ulnar deviere MP
leddene mer enn radial deviere.
- Ulnar deviasjon ved RA har som regel kontraktur i ulnar interossei.
- Dette kan testes mens man måler IMES (flex PIP, hyprex MP) og devier MP leddene
sakte ulnar og radial.
Judy Colditz foretrekker å bruke North Coast Medical sin
goniometer NC 70117
Lumbricals:
The belly arises from the profundus tendon
Usually the first and second lumbricales are unipennate and the third and fourth bipennate but
variations can occur.
Distal Attachments: To the lateral side of the extensor apparatus of the middle finger.
Both attachments of the lumbrical are mobile and the individual muscle fibers are long and
orientated longitudinally, suggesting a considerable excursion.
The innervation of the lumbricales is variable. The ulnar nerve may supply the second and
first lumbricales either in conjunction with the median nerve or alone.
Actions:
These depend on the degree of flexion/extension of the digits at the time the lumbricales act.
The lumbricales have a direct role in extension of the proximal and distal interphalangeal
joints, and add to other flexion forces at the MP joints.
As the muscle contracts, traction on the proximal attachment will tend to pull flexor digitorum
profundus distally, relaxing flexion. Traction on the distal attachment will tend to extend the
interphalangeal joints (and flex the MP joints).
The net effect is to move the finger from a flexed claw position of MP extension or
hyperextension and IP flexion (‘Intrinsic minus’) towards a posture of MP flexion and
interphalangeal extension (‘Intrinsic plus’).
The net effect on the finger tip (being opposed to the thumb) would be to change a nail- topulp pinch to a pulp-to-pulp pinch.
Actions: Extension of the interphalangeal joints while flexing the MP joints:
The moving origin of the lumbricales (the profundus) creates a complicated biomechanical
interplay of muscle forces which varies based on the position of the digit:
The lumbricales have a direct role in extension of the proximal and distal interphalangeal
joints, and add to other flexion forces at the MP joints.
As the lumbrical contracts, traction on the proximal attachment will tend to pull flexor
digitorum profundus distally, relaxing flexion force across the IP's. Concurrent traction on the
distal attachment via muscle contraction extends the interphalangeal joints (and flex the MP
joints).
The net effect is the ability of the lumbrical to move the finger from a flexed claw position of
MP extension or hyperextension and IP flexion ('Intrinsic minus') towards a posture of MP
flexion and interphalangeal extension ('Intrinsic plus').
This biomechanic interplay has two suggested functions:
1. A proprioreceptive link between the flexor and extensor tendon systems.
2. A mechanical link (mobile moderator band) alternating posture.
Dette er lange tynne muskler (a worm).
- Origin: profundus tendon (ring and little bipennate).
-
-
Insert: radial lateral band.
Normal function:
originate on a moving tendon
connecting flexor and extensors (muscles som går i to opposite directions)
able to relax its own antagonist!!!
Lumbricals er jobb hestene i ekstensor apparatet.
Primær IP ekstensjon (DIP mer enn PIP)
Den drar profundus distalt helt til det er nok slakk og da strekker den IP.
Elongation during flexion.
Lumbrical shortening test: is an active test
make a fist è less DIP flexion
active IP flexion with MP flexed è observe DIP è paradox extension as flexion is
attempted
NO active DIP flexion with MP and PIP in flexion, but OK active DIP flexion with MP in
extension.
Recommendations for hand therapists:
- For elongation of interossei and lumbrical: èBlock MP in hyper extension!!!
- Passive ROM doesn’t stretch the lumbricals it needs the profundus.
- Lumbricals need to be tested active, the elongate active
Som du kanskje ser via dette referatet var det en veldig intens workshop og ikke alltid like lett
å henge med. Jeg har prøvd så godt jeg kunne formidle det Judy sa på workshoppen hennes.
MEN jeg kan ikke garantere at alt som står her er helt riktig og fullstendig. Så ikke ta for gitt
alt jeg skrev og les det veldig kritisk.
Der jeg synes det var pratisk med lit anatomisk oppfriskning har jeg hentet bilder og tekst fra
Judy’s CD the interactive hand.