Witwer MSK study guide 1 - Upper extremity Flashcards
What spinal nerves innervate the brachial plexus?
C5 to T1
What areas are innervated by C5?
Proximal upper limb muscles
Sensory to lateral upper arm
C6 innervation allows for what movement?
Flexion of the forearm
C7 innervation allows for what movement?
Extension of forearm
C8 innervation allows for what movement?
flexion of fingers
T1 innervates what area?
Hand muscles
sensory to medial forearm to little finger
What structures make the superior border of the axilla?
Outer border of the 1st rib, superior border of the scapula, and the posterior border of the clavicle.
What structures make the anterior border of the axilla?
Pec major and minor
anterior axillary fold
What structures make the posterior border of the axilla?
Subscapularis, teres major, latissimus, posterior axillary fold
What structures make the medial border of the axilla?
Rib cage and serratus anterior
What structure makes the lateral border of the axilla?
Intertubercular sulcus
What structure makes the floor of the axilla?
armpit
What muscles stabilize the shoulder joint anteriorly?
Pec major and pec minor
What muscle stabilize the shoulder joint laterally?
Deltoid
What muscles stabilize the shoulder joint posteriorly?
trapezius, rhomboid major and minor, latissimus dorsi
What muscles stabilize the shoulder joint medially?
serratus anterior
Innervation of the deltoid?
Axillary nerve
The deltoid does abduction at the shoulder joint from
a) 0-30 degrees of abduction
b) 45-90 degrees of abduction
c) 30 plus degrees of abduction
d) 180-360 degrees of abduction
c) 30 plus degrees of abduction
The trapezius is innervated by what nerve?
CN XI
What muscles function to shrug the shoulders?
Trapezius, rhomboid major and minor
What innervates the latissimus dorsi?
Thoracodorsal nerve
What innervates the serratus anterior muscle?
Long thoracic nerve
After an axillary node dissection, a patient is now showing winging of the scapula. Which nerve was likely damaged?
Long thoracic nerve. (C5, C6, C7, wings to heaven)
Paralysis of the long thoracic nerve causes winging of the scapula
What are the rotator cuff muscles?
SITS
Supraspinatus, infraspinatus, teres minor, subscapularis
Which rotator cuff muscles insert at the greater tubercle of the humerus?
SIT
Supraspinatus, infraspinatus, teres minor
Where does the subscapularis muscle insert?
The lesser tubercle of the humerus
What degrees does the supraspinatus abduct the arm to?
from 0-30 degrees
What nerve innervates the supraspinatus and infraspinatus muscles?
suprascapular nerve
Teres minor is innervated by what nerve?
Axillary nerve
Subscapularis is innervated by what nerve?
superior and inferior subscapularis nerves
What is the acronym for the brachial plexus, and what does it stand for?
Reach To Drink Cold Beer
Roots, Trunks, Divisions, Cords, Branches
The terminal branches of the brachial plexus form what five nerves that innervate the arm, forearm, and hand?
Musculocutaneous nerve, axillary, radial nerve, ulnar nerve, median nerve
MARMU
The musculocutaneous nerve innervates what muscles, and what general functions do they preform?
Biceps brachii, Brachialis, coracobrachialis.
They are responsible for flexion of the arm and forearm, and supination.
The radial nerve innervates what muscles?
BEST
Brachioradialis, Extensors of the wrist, hand, thumb, and digits, Supinator, Triceps
The radial nerve is an extensor nerve, with one exception. What muscle is innervated by the radial nerve and is not an extensor?
Brachioradialis - forearm flexor at the elbow
Saturday night paralysis effects what nerve?
radial nerve
With what type of fracture is there concern for damage to the radial nerve?
Midshaft humerus (surgical neck) fractures can damage the radial nerve
Midshaft humeral fractures also raise concern for damage to what arteries?
Brachial and Profunda Brachi artery
Muscles innervated by the median nerve do what general functions?
“Flexor, pronator, thumb to finger approximator”
What is the TaTa sign?
Ability to flex the MCP joints while extending the IP joints
What muscles are responsible for the tata sign?
lumbricals
What flexors of the wrist and hand are innervated by the ulnar nerve rather than the median nerve?
Flexor carpi ulnaris and flexor digitorum profundus of the ring and little fingers, are supplied by the unlar nerve
T/F? A good test of the median nerve is thumb to finger approximation to the 5th digit.
False - use the index finger to test the median nerve (make an “O” with thumb and index finger).
What is the general function of the ulnar nerve?
Finger spreader nerve, assistant flexor muscles, intrinsic muscles of the hand
The intrinsic muscles of the hand are innervated by the ulnar nerve except for which muscles?
ABOF the LAW muscles ABductor pollicis brevis Opponens poillicis Flexor pollicis longus and brevis Lateral two Lubricals
What does Froment’s sign test for?
Ulnar nerve. Tests function of adductor pollicis and for ability to spread fingers against resistance. Hold piece of paper b/w thumb and index finger.
What are the five muscles of the arm and their innervation?
Biceps Brachii - musculocutaneous Brachialis - musculocutaneous Coracobrachialis - musculocutaneous Brachioradialis - radial Triceps brachii - radial
What is the order of ossification of structures in the elbow?
CRITOE
Capitulum, Radial head, Internal (Medial) epicondyle, Trochlea, Olecanon, External (lateral) epicondyle
What ages does ossification of the CRITOE structures occur?
2, 4, 6, 8, 10, 12
or
1, 3, 5, 7, 9, 11
A fat pad sign (sail sign) is suggestive of what type of fracture?
Fracture of the radial head with joint effusion
What occurs in a nursemaids elbow?
Subluxation of radial head from annular ligament
What movement should be preformed to fix a nursemaids elbow?
Supination and flexion
Compartment syndrome is characterized by what symptoms?
6 P’s
Pain (disproportional pain), paresthesia, passive stretch pain, pulselessness, paralysis, and pressure on passive extension of compartment
What artery is used to measure blood pressure?
Brachial artery
What muscles form the cubital fossa?
Brachioradialis and pronator teres
Which of the following is not found in the cubital fossa?
a) Tendon of biceps brachii
b) brachial artery
c) median cubital vein
d) tendon of brachioradialis
e) median nerve
d) tendon of brachioradialis
What is a Monteggia’s fracture?
Fracture of proximal third of ulna and anterior dislocation of the head of the radius at the elbow
What is a Galleazzi’s fracture
fracture of distal third of radius and subluxation (partial dislocation) of the distal head of the ulna
What is a Colle’s fracture?
fracture of distal radius with dorsal displacement of distal fragments
What is a TFCC and its function?
triangular fibrocartilage complex. It is an articular disc between the distal radius, ulna, and wrist joint.
It functions to stabilize the radioulnar joint
Does the hand articulate with primarily the radius or the ulna?
The radius
What two muscles are responsible for supination? What is their innervation?
Biceps Brachii - musculocutaneous nerve
Supinator muscle - radial nerve
What two muscle are responsible for pronation?
What is their innervation?
Pronator teres - median nerve
Pronator Quadratus - median nerve
Do extensors of the wrist and fingers originate from the medial or lateral epicondyle of the humerus?
Extensors originate at the lateral epicondyle
Do flexors of the wrist originate from the medial or lateral epicondyle of the humerus?
Flexors originate at the medial epicondyle.
Is tennis elbow medial or lateral epicondylitis?
Golfers elbow?
Tennis elbow = lateral epicondylitis
Golfers elbow = medial epicondylitis
The anterior/flexor compartment of the forearm is innervated most by what nerve?
Median nerve
What muscles are in the superficial layer of the anterior compartment?
Flexor carpi radialis, palmaris longus, pronator teres, and flexor carpi ulnaris
What muscles are in the intermediate layer of the anterior compartment?
Flexor digitorum superficialis
What muscles are in the deep layer of the anterior compartment?
Flexor digitorum profundus
flexor pollicis longus
Pronator quadratus
The muscles of the dorsal compartment of the forearm are innervated by what nerve?
Radial nerve
The muscles of the dorsal compartment of the forearm do what functions?
Extension of the wrist, fingers, and thumb, and supination.
* the brachioradialis is in the dorsal compartment but is a flexor of the elbow joint
The superficial layer of the dorsal compartment of the forearm contains what 8 muscles?
Extensor carpi radialis brevis Extensor digitorum Extensor digiti minimi extensor carpi ulnaris anconeus brachioradialis extensor carpi radialis longus
The deep layer of the dorsal compartment of the forearm contains what 5 muscles?
Supinator Abductor pollicis longus Extensor pollicis brevis Extensor pollicis longus Extensor indici
In carpal tunnel syndrome, you might see atrophy of what area?
Thenar eminence
The medial border of the anatomical snuff box is made by what tendon?
extensor pollicis longus tendon
The lateral border of the anatomical snuff box is made of what 2 tendons?
Extensor pollicis brevis and abductor pollicis longus tendons
What two carpal bones make the floor of the anatomical snuff box?
Scaphoid and trapezium
What vein overlies the anatomical snuffbox?
The cephalic vein
Name the bones of the wrist.
Scaphoid, Lunate, Triquetrum, Pisiform, Hamate, Capitate, Trapezoid, Trapezium
What is a sesamoid bone?
It is a bone within a tendon sheath
Which carpal bone is a sesamoid bone, and which tendon is it within?
The pisiform bone is withinin the tendon of flexor carpi ulnaris
Why are fractures of the scaphoid worrisome?
There is poor blood supply to the scaphoid, and fractures can result in avascular necrosis of the proximal fragment of the scaphoid. They are often missed on XR
What exam finding is suggestive of a scaphoid fracture?
Pain over the anatomical snuff box.
Which of the following is true?
a) the lumbrical muscles are innervated by the radial nerve
b) the lumbrical muscles are innervated by the ulnar nerve
c) The lumbricals of the 2nd and third digits are innervated by the median nerve. The lumbricals of the 4th and 5th digits are innervated by the ulnar nerve
d) The lumbricals of the 2nd and third digits are innervated by the ulnar nerve. The lumbricals of the 4th and 5th digits are innervated by the radial nerve
c) The lumbricals of the 2nd and third digits are innervated by the median nerve. The lumbricals of the 4th and 5th digits are innervated by the ulnar nerve
The majority of the intrinsic muscles of the hand are innervated by what nerve?
Ulnar nerve
What nerve is known as the “million dollar nerve”?
Why?
The recurrent branch of the median nerve.
It innervates muscles that do opposition, abduction, and flexion of the thumb. If it is damaged during surgery the patient will get a million dollar settlement.
What is the blood supply to the palm?
The superficial palmar arch and deep palmar arch. The superficial palmar arch is supplied by the ulnar artery. The deep palmar arch is supplied by the radial artery.
The superficial and deep palmar arches are typically connected by anastomoses. What test is used to check for this, and when should it be done?
Allen’s test. Should be done before obtaining an ABG from the radial artery.
What nerve innervates the coracobrachialis m and the short head of the biceps (more medially)?
Musculocutaneous n
What nerve innervates the pectoralis minor m?
And the pectoralis major m?
Medial pectoral n.
Medial and Lateral Pectoral n.
What three muscles attach to the coracoid process of the scapula?
Coracobrachialis m
Pectoralis minor m
Short head of biceps m
What three muscles attach to the greater tubercle of the humerus?
SIT muscles
Supra/infraspinatus m
Teres minor m
What nerve innervates the supra and infraspinatus m’s?
Suprascapular n
What nerve innervates the teres minor m and deltoid m?
Axillary
What three muscles attach near the bicipital groove?
Miss between two majors
Pectoralis Major
Latissimus dorsi
Teres Major
What nerve innervates the Latissimus dorsi and Teres major muscles?
Thoracodorsal n