Functional anatomy of upper limb Flashcards
wheres the thenar eminence and hypothenar eminence
which bone / bones articulate with the scaphoid & lunate?
just the radius!
why is the scaphoid a clinically significant bone? [2]
has a retrograde artery (comes in proximally and comes out distally)
if you get a fracture -> portion becomes avascular and necrotic
what movement does the radio-carpal bone permit? [2]
what movement does the mid-carpal bone permit? [2]
what movement does carpo-metacarpal bone permit? [2]
what movement does the radio-carpal bone permit? [2]
- *- flexion & extension
- adbuct & adduct**
what movement does the mid-carpal bone permit? [2]
- *- flexion & extension
- adbuct & adduct**
what movement does carpo-metacarpal bone permit? [2]
- **opposition of thumb
- very limited other movement**
what movements does the MCP joint permit? [2]
what movements does the PIP joint permit? [2]
what movements does the DIP joint permit? []
what movements does the MCP joint permit? [2]
- *- flex & extend
- abduct & adduct**
what movements does the PIP joint permit? [2]
- *- flex & extend
- abduct & adduct**
what movements does the DIP joint permit? [1]
- flex & extend
(thumb)
abducted & extended
what are the characteristics of power grip?
and subtypes? [3]
- *power grip**
- all fingers flexed around object, thumb curled around to press agaisnt / meet fingers
- all muscles closing hand are active
- wrist extensors are active - stable base
- most primitive (new borns can do)
i) hook or snap
ii) cylindrical grasp
iii) spherical grasp
what are the two main types of grip? [2]
which is more complex to perfom?
- power grip
- precision grip - more complex
what do patients with radial nerve palsy struggle to be able to do?
why?
what do patients with radial nerve palsy struggle to be able to do?
- power grip
why?
- wrist extensors are active when performing a power grip - causes stabilisation
what are the characterisitcs of precision grip?
what are the characterisitcs of precision grip?
- object held between tip of thumb and 1,2 or 3 fingers
- intrinsic muscles involved, co-operative with long flexor and extensor muscles
- complex - takes around 9 months to learn
power
what are 4 muscles of thenar emincence? & innervation?
- flexor pollicis brevis - median nerve
- oppenens pollicis - median nerve
- abductor pollicis brevis - median nerve
- adductor pollicis - ulnar nerve
flexor digit minimi
oppenens digiti minimi
abductor digiti minimi
which muscles are your lumbricles?
- which muscle do they arise from?
- what movements do they cause of MCP [1] & IP [1]?
- innervation/
which muscles are your lumbricles?
which muscle do they arise from:
- flexor digitorum profundus
what movements do they cause of MCP [1] & IP [1]
- MCP: FLEX
- IP: EXTENSION
innervation
2 median, 2 ulnar
which muscles are your dorsal interossei?
- what movements do they cause of fingers?
innervation?
dorsal interssei ABduct: DAB
cause abduction of fingers
ulnar innervation
which muscles are your palmar interossei?
- what movements do they cause of fingers?
innervation?
which muscles are your palmar interossei?
what movements do they cause of fingers: adduction - PAD !
innervation ulnar nerve
intrinsic muscles of the hand:
hypothenar eminence, medial 2 lumbricles, all dorsal and palamar interossei & adductor pollicis are innverated by which nerve?
thenar eminence & lateral 2 lumbricles are innverated by which nerve?
hypothenar eminence, medial 2 lumbricles, all dorsal and palamar interossei & adductor pollicis are innverated by ulnar nerve
thenar eminence & lateral 2 lumbricles are innverated by: median nervce
which three nerves are involved in moving muscles of the hand?
musculocutaneous
median
ulnar
axillary
radial
which three nerves are involved in moving muscles of the hand?
musculocutaneous
median
ulnar
axillary
radial
fyi !
mid-humeral shaft fracture is a risk of damaging which nerve?
musculocutaneous
median
ulnar
axillary
radial
mid-humeral shaft fracture is a risk of damaging which nerve?
musculocutaneous
median
ulnar
axillary
radial
radial nerve palsy is characterised by what? [2]
what can tempoary radial nerve palsy be caused by? [1]
radial nerve palsy is characterised by what? [2]
- wrist drop (lost innervation of extensors - creates unopposed flexion)
- *- weak power grip**
what can tempoary radial nerve palsy be caused by? [1]
- saturday night palsy (compression of nerve in armpit)
fyi
innervation of median nerve at supracondylar fractures of the humerus causes what?
- ask a patient to make a fist, can flex 4 & 5 (bc innervated by ulnar nerve), but cant flex the first three digits (MCP joints, 2&3 PIP joints & 2&3 DIP joints)
what is a common low median nerve injury? [1]
carpal tunnel syndrome: any condition in which carpal tunnel is compressed & causes median nerve compression
- progessive loss of co-ordination and strength in thumb
- pins and needles
fyi
what does high ulnar nerve injury cause?
what does low ulnar nerve injury cause?
high ulnar nerve injury: all muscles lost - neutral position
what does low ulnar nerve injury: clawing of the hand
= ulnar paradox !! bc higher up injury = less bad outcome
which nerves provide the sensory innervation of the following places?
where do you test for sensory innervation for
a) radial nerve
b) median nerve
c) ulnar nerve
where do you test for sensory innervation for
a) radial nerve: between thumb & first thing dorsally
b) median nerve: outside of second finger
c) ulnar nerve: outside of little finger
ulnar nerve - low
radial
median
ulnar
