Robertson: Putting It All Together Flashcards
(69 cards)
What happens when you have C5/6 palsy?
absence of shoulder abduction and external rotation (axillary)
no elbow flexion (musculocutaneous)
What happens when you have damage to C5/6/7 ?
lack of wrist and finger extension (add in radial)
What happens when you have damage to C8/T1? What causes this?
intrinsic wasting of hand muscles; caused by a traction mechanism
What are some things that can occur as a result of a spinal avulsion (preganglionic lesion)
Horners (sympathetic chain)
Elevated hemi diaphragm (phrenic)
Winged scapula (long thoracic)
Absence of rhomboid (dorsal scapular)
How to you treat a spinal avulsion?
nerve/tendon transfers
What is the most common way to damage the radial nerve?
mid shaft fracture (radial nerve travels along the spiral groove of the humerus)
What should you ask your patient to do in order to check for radial nerve function?
give a thumbs up
**tests extensor pollicis longus
What are the first few muscles that recover following radial nerve damage?
extensor carpi radialis brevis
supinator
extensor carpi ulnaris
What are the last few muscles to recover following radial nerve damage?
extensor pollicis longus
extensor pollicis brevis
extensor indices
What is Saturday night palsy?
radial neuropathy caused by lying on the arm where the radial nerve spirals around the humerus (i.e. drunk at a bar)
4 key features of the claw hand
MP hyperextension
no finger abduction or adduction **loss of palmar/dorsal interossei
weak grip
lack of key pinch
What muscle of the thumb is responsible for key pinch?
adductor pollicis
Damage to the ulnar nerve causes intrinsic (blank) of the hand and the loss of the (blank) arch
wasting; palmar
3 signs to test for ulnar nerve damage
Fromont’s sign
Wartenberg’s sign
Bouvier’s maneuver
Explain Fromont’s sign to test for ulnar nerve damage. What muscle is this specifically testing?
To perform the test, a patient is asked to hold an object, usually a flat object such as a piece of paper, between their thumb and index finger (pinch grip). The examiner then attempts to pull the object out of the subject’s hands. This is testing adductor pollicis function.
a neurological sign consisting of abduction of the fifth finger, caused by unopposed ulnar insertion of the extensor digiti minimi
Wartenberg’s sign
What two muscles in the forearm does the ulnar nerve innervate?
FCU
2 digits of the flexor digitorum profundus *single muscle belly and tendon
What innervates the interossei in the hand? How many palmar interossei are there? What action do they perform? How many dorsal interossei? What action do they perform?
ulnar nerve; 3 palmar cause adduction; 4 dorsal cause abduction
**interossei cause flexion at MP and extension at PIP
The interossei attach (blank) to the axis of rotation at the MP joint, so they cause flexion. Their tendons pass (blank) to the axis of rotation at the PIP and DIP, so they cause extension at PIP/DIP.
anterior or palmer; dorsal
What muscle originates on a finger flexor and inserts onto a finger extensor?
lumbricals **originate from FDP and insert on extensor expansion (index through little finger)
This muscle passes palmer to axis of rotation at MP joint
Dorsal to axis of PIP joint
And has an origin and insertion into a tendon
lumbrical
What muscle are you testing for when assessing key pinch? Damage to what nerve causes this phenomenon?
adductor pollicis; ulnar nerve
So, list all of the muscles in the hand that have innervation by the ulnar nerve
adductor pollicis
hypothenar muscles: abductor digiti minimi** (main one in which you see disfunction), opponens digiti minimi, flexor digiti minimi brevis
ulnar lumbricals
dorsal and palmar interossei
How do you differentiate an ulnar nerve lesion at Guyon’s canal (wrist) vs the elbow?
If sensation over dorsum of wrist on ulnar side, the ulnar nerve is OK at the elbow (dorsal sensory branch leaves the ulnar nerve proximal to the wrist and goes unto dorsum of hand). Nerves that go through guyon’s canal just innervate the tips of fingers.
