Movement of the hand Flashcards
what is the joint called that articulates between the carpals and metacarpals
carpometacarpals
what is the joint called when the metacarpals articulate to the carpals
metacarpophalangeal joints
what are the movements of the metacarpophalangeal joints
flexion
extension
abduction and adduction
what are the joints between the phalanges
- Proximal interphalangeal (PIP) and distal interphalangeal (DIP)
what are the movements on the interphalangeal joints
flexion
extension
what are the joints in the thumb
- Has 1 MCP and has 1 interphalangeal joint as it only has two phalanges
what are the movements of the thumb
- Flexion – moves the thumb across the palm of the hand
- Extension – returns from flexion and continues
- Abduction – takes the thumb away from the palm at right angles
- Adduction – return from abduction
- Opposition – combination of flexion, medial rotation and abduction at CMC (carpometacarpal joint) and flexion at IP
where do the muscles that move the fingers originate
- Partly in hand (intrinsic) and partially in forearm(extrinsic) with tendons going into hand
why aren’t the muscles present in the hand
- Haven’t go enough space to but big powerful muscles in the hand therefore they are put in the forearm
describe the muscles of the hand and how they lead into tendons
- Muscle is housed in the forearm but the tendons from the muscle pass over the wrist to the palm of the hand and to the fingers
- They have long tendons that go into the hand, these are both flexors and extensors that are in the posterior compartment of the forearm
- Muscle is weaker than the tendon, therefore the muscle tends to tear rather than the tendon
what are the attachment point for muscles that go into the forearm
medial and lateral epicondyles
where is the common origin of the flexors
medial epicondyle
where is the common origin for the extensors
lateral epicondyle
what are the superficial layers of flexors responsible for
responsible for flexing the wrists
what makes up the superficial flexors
– Pronator teres,
– Flexor carpi radialis
– Palmaris longus
– Flexor carpi ulnaris
where do the flexor carpi radials and flexor carpi ulnas go to
they go to the carpals
where does the palmar is longus go to
– small muscle that tenses the palmer apenruosis
what does the bronchioradialis do
- part of the superficial flexros
- technically it is a muscle in the posterior compartment - innervated by the radial nerve this proves that it is in the posterior compartment
what are the muscles that are responsible for closing the hand
- flexor muscles
- flexor digitorum superficialis
- Flexor digitorum profundus
- Flexor pollicis longus
where does the flexor digitorum superficialis originate from, and what does it split into
comes from the medial epicondyle
this divides into 4 tendosn, these go through the carpal tunnel and down to the digit
where does the Flexor digitorum profundus originate from and what does it divide into
this start in the ulnar
this divides into the 4 tendons that go through the carpal tunnel an into the digits
how many tendons does the flexor polices longus have
- it has 1 tendon
why do tendons need to be protected
- Can become damaged if they rub on the bone therefore they need to be protected especially when they go through the carpal tunnel
what is the tendon sheath full of
synovial fluid
what does the retinaculum do
– holds tendons in place as they go through the carpal tunnel
what goes through the carpal tunnel
- 9 tendons and this nerve that goes underneath with those tendons is the median nerve
what protects tendons int he digits
- In the fingers there are digisit tendon sheaths – bands of tissue that hold them in place and firmly attach them to the fingers
how are tendons protected in the hand
- Protect them by wrapping them in a tendon sheath which is full of synovial fluid, it enters the common flexure sheath, it wraps around them forms a cushion protecting them, the tendons then come out and as they go into the fingers they re-enter tendon sheaths as they run close to the phalanges of the bones and they could be damaged as they run through the fingers
describe how the tendons FDS and FDP are protected
- Tendons of FDS and FDP enter common flexor sheath deep to flexor retinaculum
- In central compartment they separate into respective digital synovial sheaths
- Synovial sheaths held in place by fibrous digital tendon sheath
what is synovial fluid made out of
- blood plasma and hyaluronic acid
what happens if the tendon sheaths tear
- If the tendon sheaths tear and become damaged then the synovial fluid can leak out, the blood plasma can be reabsorbed but the hyaluronic acid is not reabsorbed and this forms a lump where the tear is and no has a consistency of thick set honey which forms a cyst
- They have a stalk where the tendon sheath is stored
- Only surgically removed when they compress a nerve or blood vessel
what is the carpal tunnel
- this is a dense thick flexor retinaculum sheath
where do the ulnar artery and nerve travel in respect to the carpal tunnel
- they travel above the carpal tunnel
what goes through the carpal tunnel
- Median nerve goes underneath the retinaculum sheath with the tendon sheaths
what happens when the size of the carpal tunnel is reduced
- compresses the median nerve and leads to median nerve problems
what does the median nerve innervate
gives sensation to thumb half of ring finger and index finger, innervates the thenar muscle group at the base of the thumb
what does Flexor digitorum superficialis (FDS) do
- Flexes MCP and PIP
what does Flexor digitrum profundus (FDP) do
- Flexes MCP, PIP and DIP
describe how FDP and FDS interact
FDP has to go through the tendon of FDS, the tendon of FDS splits and FDP goes through it, so it can inset onto the distal phalange
what does Flexor pollicis longus do
flexes MCP and IP of the thumb
what do instruct muscles of the hand do
- Intrinsic muscles of the head help close the hand, act on the thumb (thenar muscles) and little finger (hypothenar muscles)
- Instrinsic muscles are between the metacarpals, they help with the movement of the fingers
what are the muscles of the thumb
thenar muscles
what are the muscles of the little finger
hypothenar muscles
what is the cause of trigger finger
- If tendons of FDS and FDP enlarge proximal to tendon sheath person is unable to extend the finger
- If extended passively a snap is audible as tendon moves into sheath
- Normally is resolved by a few months
what are the muscles responsible for opening the hand
Extensor digitorum communis, - 4 tendons Extensor indicis - index finger Extensor digiti minimi - little finger
where are the muscles responsible for opening the hand based and what innervates them
Posterior side of the forearm
- all innervated by the radial nerve
what forms the anatomical snuff bock
- extensor pollocis longus, extensor pollicis brevis, abdouctor pollics longus
how are the tendons in the anatomical snuff box protected
- there is no common sheath, but there is an extensor retinaculum, they are protected especially over the wrist and as they go over the carpals by tendon sheaths, they are held against the carpal bones
what movements does the anatomical snuff box do
- they extend the thumb and abduct the thumb
what is the dorsal expansion
- tendons insert onto dorsal surface of fingers via a complex arrangement of fibrous tissue; dorsal expansion
what does tendon extensor digitorium do
.- forms protective band over flexors linking in to the dorsal expansion are the intrisc muscles of the hand, these are the small muscles that will do the intrinsic movements
what does thenar muscles do
– act of the thumb – this has flexors, opposition muscles
what do the hyothenar muscles do
– act on the little finger – this has flexion, opponens muscles that help with opposition
what are the intrinsic muscles of the hand
- Lumbricals, flex MCP and keep these interphalangeal extended joints of 2nd-5th digits – insert into the dorsal expansion which is the extensor muscles
- Dorsal interossei, abduct 2nd-4th digits. Assist lumbricals
- Palmar interossei, adduct 2nd,4th and 5th digits, assist lumbricals
- PAD and DAB
- PAD – adduct palmar interossei
- DAB – abduct dosal interossei
describe the fascia of the hand
- Fascia of palm and dorsum of hand continuous with antebrachial fascia (fasica in the forearm)
- Thin over thenar and hypothenar muscles as these are muscles and you want them to move but it is thick in central areas such as at the palmer aponeurosis
what are the two spaces in the fascia of the hand
• Two potential spaces midpalmar and thenar bounded by fibrous muscle septa – if these open up it can cause a problem if there is an infection
what are the causes of compartment syndrome o fate hand
- Caused by trauma and most often iatrogenic causes (something that the medical professional has caused and it happens further down in the arm due to the infection)
what is the treatment of compartment syndrome of the hand
- fasciotomy
what cuts have to be made in a fasciotomy of the hand
- 2 dorsal
- 1 lateral
- 1 medial or 1 carpal tunnel
what is dupuyten’s contracture
- Palmer fascia can get thicker or have the wrong type of collagen in it this can cause dupuyten’s contracture
- Fixed flexion contracture of the hand
- Palmar fascia thickens – collagen type 1 to collage type III
who does dupuyten’s contracture effect
- Northern European
- Men 10:1
- Greater than 40 years
- Family history
- Liver cirrhosis
