UPPER LIMB FORUM –Group Answers
MOI=mechanism of injury
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Study Questions
1.
Define the difference between shoulder separation and shoulder dislocation. Sep.
involves injury to the coracoclavicular joint & AC joint. Dislocation involves hum. Head
displaced out of GF.
Shoulder separation-MOI-fall or impact, shoulder appears “depressed”



A mild shoulder separation involves a sprain of the AC ligament that does not move the
collarbone and looks normal on X-rays.
A more serious injury tears the AC ligament and sprains or slightly tears the
coracoclavicular (CC) ligament, putting the collarbone out of alignment to some extent.
The most severe shoulder separation completely tears both the AC and CC ligaments and
puts the shoulder joint noticeably out of position.
Shoulder dislocation-MOI-sudden impact applied to the humerus when the joint is fully abduct,
(ant -inf dislocation- tilts humeral head downward onto inf weak part of capsule which tears; the
humeral head is displaced out of the glenoid fossa; acronium acts as a fulcrum) ant and inf
(usually), greater and lesser tuberosity may be sheared , axillary N (paralysis of deltoid M) or
radial N may also be damaged.
2.
What is the clinical significance of the radial groove?
Contains radial N and profunda brachial A, if frac occurs in mid 1/3 rd of radiusN damage
may result
3.
List the rotator cuff muscles, their nerve supplies, origins, insertions, and functions.
SITS-Provide the stability of the shoulder joint.
Supraspinatus M-insert greater tubercle of humerus
Infraspanatus M-lateral to the greater tubercle of humerus?
Teres min- inferior facet of greater tubercle of the humerus
Subscap M- LESSER tubercle of humerus
Muscle
Origin on
scapula
Attachment on
humerus
Function
Innervation
Supraspinatus
muscle
supraspinous
fossa
greater tubercle
abducts the arm
Suprascapular nerve
(C5, C6)
Infraspinatus
muscle
infraspinous
fossa
greater tubercle
laterally rotates the
arm
Suprascapular nerve
(C5-C6)
Teres minor
muscle
lateral border
greater tubercle
laterally rotates the
arm
Axillary nerve (C5)
Subscapularis
muscle
subscapular
fossa
lesser tubercle
medially rotates the
humerus
Subscapular nerve
(C5-C6)
4.
What is the segmental innervation of the following muscles, and the cord of the brachial
plexus involved?
a.
b.
c.
d.
e.
f.
Supraspinatus-suprascapular n. (C5,C6), upper trunk
Infraspinatus- suprascapular n. (C5,C6), upper trunk
Teres minor-Axillary n. (C5,C6), posterior cord
Subscapularis-Upper and Lower subscapular n. (C5,C6)-posterior cord
Deltoid-Axillary n. (C5, C6)-posterior cord
Levator scapulae-Dorsal Scapular Nerve (C5 root)-upper trunk
5.
On the figures below, label all muscles that either originate or insert on the scapula.
Study Questions
1.
Define the muscular walls of the axilla. (See COA Fig. 6.23(B) and GD pg. 437
SEE CLASS NOTE SLIDE REGARDING WALLS OF AXILLA….
Pect major, subclavious, pect min, serratous ant, teres minor, lats dorsi, teres major
2.
Define the distribution of the clavipectoral fascia.
….Surround subclavius/pect m
-costocoracoid membrane(includes subclav and pect min)- upper segment (named for med/lat
attachments)peirced by 3 structures—cephalic v, thoracoacromial a, lateral pectoral n (pect
maj n)
-suspensory ligament of axilla- lower segment-fuses with axillary F at axially floor
(attached above to the clavicle, below, it encloses pectoralis minor and continues down as the
suspensory ligament of the axilla and joins the fascial floor of the axilla. )
3.
Into what large vessel does the cephalic vein drain? Axillary Vein
4.
What is the principal function and innervation of the pectoral muscles? Ribs move up if
you fix scapula and flex pects.
lateral pectoral nerve and medial pectoral
nerve
Clavicular head: C5 and C6
Sternocostal head: C7, C8 and T1
Action:
Clavicular head: flexes the humerus
Sternocostal head: extends the humerus
As a whole, adducts and medially rotates
the humerus. It also draws the scapula
anteriorly and inferiorly.
Medial pectoral nerves (C8, T1)
Action:
5.
It stabilizes the scapula by drawing it
inferiorly and anteriorly against the
thoracic wall.
What structure occupies the bicipital groove=intertubercular groove?
Medial-teres major, floor-latissimus dorsi, lateral-pectoralis major (“a Lt. btwn. 2 Majors”)
6.
What happens to the scapula following complete section of the long thoracic n.?
Winging of the scapula may occur if you fixate your hands on a wall. Injury: Any blow to the
ribs…scapula is superficial to the muscle.
7.
Explain the anatomical location of each of the three cords of the brachial plexus.
First part - the part of the artery medial to pectoralis minor
Second part - the part of the artery that lies behind pectoralis minor
Third part - the part of the artery lateral to pectoralis minor
8.
Outline the anatomical location of each of the three parts of the axillary artery, and
identify the branches of each.
1-supreme thoracic A,2-thoracoacromial A, lateral thoracic A,
S-supreme thoracic A.
T-Thoracoacromial A. (branches into ACPD: acromion, clavicular, pectoral, deltoid)
L-Lateral Thoracic A.
A-Anterior Circumflex Humeral A.
P-Posterior Circumflex Humeral A.
S-Subscapular A.
9.
10.
Draw and label a complete brachial plexus
.
Study Questions
1.
What is the significance of collateral blood supply/circulation?
Anastamoses , multiple blood sources…to compensate for collapse or blood loss, trauma, etc.
2.
The medial, lateral, and posterior cords of the brachial plexus are named due to their
position relative to what structure?
THE SECOND PART OF THE AXILLARY ARTERY.
3.
List at least one motor deficit that would follow section of each of these nerves at the
indicated places:
a. median nerve, proximal to the elbow –
Hand of Benediction-can’t flex digits 2 &3.
Flexor carpi ulnaris…a flexor on the forearm (flexes wrist) , so can’t flex wrist
Loss of pronation, denervation of PQ &
Lumbricals gone?
Recurrent branch of median nerve…innervates the thenar muscles. (FIND IN
CADAVER!!!)
b. ulnar nerve, proximal to the elbow : FDP tendons to digits 4 & 5. Abductor 4 & 5.
Everything but 2 LOAF. Hypothenars gone. Abductors gone. Lumbricals 4 &
5 lose add of thumb, add flex opposition of little finger (little finger can only
extend)
c.
axillary, at the shoulder deltoids and teres min hurt-lose abd up to 90: Teres
minor and deltoid, would result in probs w/lat. Rotation, &
d.
radial, proximal to the origin of the tricepsext of the forearm (best acronym
anconeus helps triceps extend) Wrist drop-can’t extend wrist, biceps brachii would work,
lose sensory to dorsum behind thumb & snuffbox, could not extend forearm due to triceps
knocked out…problem is proximal to the origin of the triceps muscle.
e.
lower subscapular, near its origin- medial rotation (inner- teres maj and
subscapularis-medially rotates & stabilizes shoulder joint)[suprascap N does
infraspinatous and infraspinatous]: Teres major responsible for medial rotation and
ADDuction…would lose these b/c teres major innervated by lower Subscapular n.
f.
musculocutaneous nerve, in the axilla-biceps, brachialis, brachioradialislose
flexion of forearm: biceps would be flexion-deficient, brachialis would not be able to
flex, loss of sensation in lateral forearm.
4.
Draw upper limb with dermatome level map.
C6 thumb and index
C8 fingers 4 & 5
C7 middle finger
5.
Describe the boundaries of the cubital fossa.
Lat border –brachioradialis
Protonator teres forms medial border
6.
List in order, the mediolateral relationships of the biceps Tendon, median Nerve, and
brachial Artery in the cubital fossa.
TAN ( Lateralmedial)
Biceps Tendon, brachial Artery, median Nerve
7.
In the figure below, which is a section through the arm at the humeral mid-shaft, label the
structures indicated.
a-biceps brachii
b-brachialis
c-cephalic V
d-musculocutaneuos N
e-medial cutaneous N
f-brachial A
g-basilic V
h-ulnar N
I-long head of triceps
j-medial head of triceps M
k-lateral head of triceps
l-radial N
m-profunda brachii A
Study Questions:
1.
List the muscles associated with the common flexor tendon of the forearm.
The common flexor tendon is a tendon shared by a number of superficial flexor muscles
in the forearm. It attaches to the medial epicondyle of the humerus.
It serves as the origin (in part) for a number of muscles (the superficial muscles of the
anterior compartment of the forearm)
2.
Pronator teres
3.
Flexor carpi radialis
4.
Palmaris longus
5.
Flexor digitorum superficialis
6.
Flexor carpi ulnaris
7.
Describe the course of the median nerve in relation to the pronator teres and
flexor digitorum superficialis.
Superior to fds
8.
In the figure below, which is a cross-section of the wrist through the distal carpal
row, identify the tendons, nerves, arteries, and bones.
A trapesium
Btrapezoid
C capitate
D hamate
E palmar cutaneous branch of median nerve
F ulner artery
G ulner nerve
H median nerve
I flexor digitorum superficialis
J flexor digitorum profundus
K flexor pollicis longus
L flexor carpi radialis
M extensor carpi ulnaris
N extensor digiti minimi
O extensor digitorum and extensor indicis
P exgtensor carpi radialis longus and brevis
Q extensor pollicis brevis
R absuctor pollics longus
S radial artery
T extensor pollicis longus
4.
What is carpal tunnel syndrome? What are the physical symptoms of a patient with
it? Pressure on the median n. in the carpal tunnel.
Carpal tunnel is the concave anterior surface of the carpal bones and closed by the
flexor retinaculum (packed with long flexor tendons of the fingers and their surrounding
synovial sheaths and the median nerve). Carpal tunnel syndrome is produced by
compression of the median nerve w/in the tunnel, and is sometimes caused by thickening
of the synovial sheaths of the flexor tendons or arthritic changes in the carpal bones.
Physical symptoms are burning pain along the distribution of the median nerve to the
lateral 3.5 fingers and weakness of the thenar muscles.
5.
If a patient suffers a fracture at the medial epicondyle of the humerus, what nerve is
most likely to be injured? Ulnar nerve-what motor deficits do they have? What sensory
deficits do they have????
6.
What is a Colles' fracture? Besides an x-ray, what is an obvious indication that a patient
has a Colles' fracture? PG. 480 Dinner-fork deformity of the wrist. The bump would be on
the posterior (dorsal) surface of the wrist due to the displaced bone fragment. Usually the
two styloid processes are at the same level (side-by-side) in the X-ray.
Colles fracture is fx of the distal end of the radius resulting from a fall w/ outstretched hand. (Occurs in old
people). The force drives the distal fragment posteriorly and superiorly, and the distal articular surface is
inclined posterior
Study Questions
1.
What are the principal digital movements mediated by the: a) palmar interossei; b) dorsal
interossei? Abduction and ADDuction. Extend the IP’s while flexing the MP joints with the
Lumbricals.
2.
What is the extensor expansion and what muscles insert into it? Pg 590 Fibrous sheaths serve as
attachment for interossei and lumbricals. It is an extension of the extensor tendon.
3.
Define the boundaries of the "anatomical snuff box" and list its key contents. Hold hand in
anatomical position w/palm forward….contents are radial artery-responsible for the radial pulse,
bone on floor of snuffbox is the Scaphoid.
Running at the floor:
radial artery (9) giving the dorsal carpal branch (10)
Running at the roof: branches of the superficial branch of radial nerve
Borders:
Tendon of abductor pollicis longus (16) and extensor pollicis brevis (15)
Tendon of extensor pollicis longus (14)
4.
What are the osseous attachments of the extensor retinaculum? Pisiform and hamate
5.
Know this!!! Know which fingers are C6, C7, C8…know what nerves are at that level….In the
following diagram identify the cutaneous distribution of the median, ulnar and radial nerves.
6.
The muscles of the hand receive motor input from the median and ulnar nerves. List the motor
deficits that will result from nerve injury at the indicated locations:
7.
Median nerve, proximal to flexor retinaculum (as in wrist slashing):2LOAF
8.
Ulnar nerve, at the wrist (ulnar nerve entrapment):