upper extremity nerves Flashcards
upper extremity nerves
- axillary (C5-C6)
- Musculocutaneous (C5-C7)
- Radial (C5-T1)
- Median (C5-T1)
- Ulnar (C8-T1)
- Reccurent branch of median nerve (C5-T1)
axillary nerve - origin
C5-C6
causes of axillary nerve injury
- fractured surgical neck of humerus
2. anterior dislocation of humerus
presentation of axillary nerve injury
- flatened deltoid
- Loss of arm abduction at shoulder (>15 degrees)
- Loss of sensation over deltoid muscle and lateral arm
musculocutaneous nerve origin
C5-C7
causes of musculocutaneous nerve injury
upper trunk compression
presentation musculocutaneous nerve injury
- loss of forearm flexion and supination
2. loss of sensation on lateral forearm
Radial nerve - origin
C5-T1
causes of radial nerve injury
- midshaft fracture of humerus
2. compression of axilla
causes of radial nerve injury - compression of axilla due to (e.g.)
- crutches
2. sleeping with arm over chair (Saturday night palsy)
Saturday night palsy
radial nerve injury due to sleeping with arm over chair
presentation of radial nerve injury
- wrist drop
- decreased grip strength
- loss of sensation of over posterior arm/forearm and dorsal hand
forearm is the part of the body which extends from
the elbow to the wrist
arm is the part of the body which extends from
shoulder to the elbow
radial nerve injury - wrist drop due to loss of
elbow, wrist, and finger extension
radial nerve injury - decreased grip extensor - why?
wrist extension is necessary for maximal action of flexors
median nerve - origin
C5-T1
causes of median nerve injury
- supracondylar fracture of humerus (proximal lesion)
- carpal tunnel syndrome (distal lesion)
- wrist laceration (distal lesion)
median injury - presentation
- ape hand 2. Pope’s blessing 3. loss of wrist flexion
- loss of thumb opposition 5. loss of lumbricals of 2nd and 3rd digits 6. loss of flexion of lateral fingers
- loss of sensation over thenar eminence
- loss of sensation at dorsal and palmar aspects of lateral 3.5 fingers (proximal lesion)
- Tinel sign (in carpal tunnel syndrome)
sensation on in proximal lesions
ape-hand deformity
Lack of ability to abduct, flex and oppose the thumb due to paralysis of the thenar muscles
Tinel sign
tingling on percussion
pope’s blessing sign is also called
Hand of benediction
pope’s blessing sign (Hand of benediction)
The ability to flex the digits 2–3 at the metacarpophalangeal joints is lost as is the ability to flex and extend the proximal and distal interphalangeal joints
ulnar nerve origin
C8-T1
causes of ulnar nerve injury
- fracture of medial epicondyle of humerus funny bone (proximal lesion)
- fractured hook of hamate (distal lesion)
funny bone
the part of the elbow over which passes the ulnar nerve
presentation of ulnar nerve injur
- ulnar claw on digit extension 2. radial deviation of wrist UPON FLEXION (proximal lesion) 3. Loss of wrist flexion 4. loss of flexion of medial fingers 5. loss of abduction and adduction of fingers (interossei)
- loss of actin of medial 2 lumbrical muscles
- loss of sensation over medial 1.5 fingers including hypothenar eminence
interossei refer to
muscles between certain bones
Reccurent branch of median nerve - origin
C5-T1
causes of Reccurent branch of median nerve injury
superficial laceration of palm
presentation of Reccurent branch of median nerve injury
- ape hand (loss of thenar muscle group: opposition, flexion, abduction
- no loss of sensation
flatened deltoid - nerve?
axillary
ape hand - nerve ?
- median
2. reccurent branch of median nerve
ulnar claw - nerve?
ulnar
decreased grip strength - nerve ?
radial
pope’s blessing - nerve ?
median
tinel sign of hand?
carpal tunnel syndrome
supracondylar fracture of humerus - nerve injury?
median
wrist drop - nerve?
radial
loss of foreman supination - nerve?
musculocutaneous