PNI Videos Flashcards
name 3 indications of ulnar nerve injury.
- claw hand
- wartenberg’s sign
- unable to cross fingers
in ulnar nerve injuries there may be wasting of which muscles?
first interossei
claw hand deformity may occur if the injury occurs where?
ulnar nerve below the elbow
why does the claw hand occur?
FDP works but intrinsics that straighten the fingers are not working - FDP takes over and causes clawing of the fingers
claw hand is only seen when?
when there is an active attempt to flew the fingers - when hand is relaxed/extended, claw appearance disappears
in a distal ulnar nerve injury you lose innervation to which muscles?
all interosseii and the ulnar 2 lumbricals
what is wartenberg’s sign?
abduction of the 5th finger - due to ulnar nerve palsy
wartenberg’s sign is caused by what?
an unopposed action of the ulnar insertion of extensor digiti minimi, the interosseous muscle that adducts the finger is not working
which muscle is “lost” in wartenberg’s sign?
fifth interosseous muscle
which interossei muscles adduct?
palmar (PAD)
which interossei muscles abduct fingers?
dorsal interossei (DAB)
froment’s test is used to test for what?
ulnar nerve palsy/cubital tunnel syndrome
describe a positive froment’s sign.
thumb IP joint will flex if adductor pollicis muscle is weak due to an ulnar nerve palsy
name 2 indications of a high median nerve injury/anterior interosseous nerve injury.
- sign of benediction
- cannot do the ok sign
prolonged compression or injury of the median nerve may result in what?
sign of benediction
when does the sign of benediction occur?
when a pt. with a high median nerve injury is trying to make a fist
which muscles are paralyzed in the sign of benediction?
- FDS
- FPL
- FPB
- radial half of the FDP
why are digits 4 and 5 flexed during the sign of benediction?
the only remaining functioning flexor muscle is the ulnar half of the FDP - flexes digits 4 and 5
ulnar claw hand refers to damage of the ulnar nerve ___ the elbow.
below
ulnar claw hand occurs when the pt. is attempting to ___ all the digits.
extend
name 2 default positions (conditions) of the injured hand at rest.
- claw hand
- ape hand
in ape hand, which muscle moves the thumb?
adductor pollicis - even though it is an ulnar nerve innervated muscle - brings thumb into the same plane at the other digits
in ape hand, which muscle moves the thumb?
adductor pollicis - even though it is an ulnar nerve innervated muscle - brings thumb into the same plane at the other digits
which test tests for anterior interosseous nerve injury?
ok sign
pt with paralysis of which nerve is unable to make an ok sign?
anterior interosseous nerve injury
which muscles are paralyzed in the ok sign/anterior interosseous nerve injury?
FPL and lateral part of flexor digitorum
a high radial nerve injury will cause what?
wrist drop
high radial nerve injuries usually occur due to what?
fractures of the distal third of the humeral shaft
what is a fracture of the distal third of the humeral shaft known as?
holstein-lewis fracture
a holstein-lewis fracture will result in paralysis of what?
the wrist and finger extensors
the patient will not be able to do what in a holstein-lewis fracture?
hitchhike position or finger extension
a low radial nerve injury affects what?
fingers and thumb extension
which nerve is affected in low radial nerve injuries?
posterior interosseous nerve
if a patient does not have wrist drop and still cannot perform the hitchhike sign then check for what?
posterior interosseous nerve injury
if a patient does not have wrist drop and still cannot perform the hitchhike sign then check for what?
posterior interosseous nerve injury
