Dermatome: dermis area of skin supplied by a specific spinal nerve segment
Root of the neck and extending to the shoulder - C
4
Skin over deltoid and lateral side of the arm - C
5
Lateral side of forearm (musculocutaneous) and thumb (flexor by median, dorsum by radial) – C
6
Index, Middle and ring fingers – C
7
Middle of posterior surface of forearm– C
7
-
Little finger (ulnar), medial side of hand and forearm – C
8
Medial forearm- med. cutaneous N of forearm (C
8
,
T
1
)
Medial side of the elbow and Lower part of the medial side of the arm (cutaneous N of arm) - T
1
Axilla and upper part of medial side of arm (intercostal brachial) -T
2
Clinical: loss of or altered sensation at a particular region of the skin indicates the spinal nerve segment involved in the damage
Muscles of anterior compartment of arm: musculocutaneous nerve (except lateral part of brachialis – by radial N)
Muscles of anterior compartment of forearm: median nerve (except FCU & medial half of FDP – by ulnar N)
Intrinsic muscles of the hand: most (including adductor pollicis) supplied by ulnar nerve except for thenar muscles and lateral 2 lumbricals, which are supplied by the median nerve
All muscles of posterior compartment of the arm and forearm are supplied by the radial nerve
Joint movements: (testing joint movements and nerve root involved)
Abduction of shoulder - C
5
Flexion of the elbow - C
6
Extension of the elbow - C
7
Flexion of the fingers - C
8
Abduction & adduction of middle 3 fingers (index, middle & ring) - T
1 o Done by interossei muscles (palmar = adduction, dorsal = abduction) (PAD DAB)
Clinical: loss of or altered movement at particular joint indicates spinal nerve & nerve segment involved in damage
In an unconscious patient, both somatic sensory and motor functions of the spinal cord levels can be tested using tendon reflexes: o Biceps jerk: a tap on the tendon of biceps in the cubital fossa- tests mainly for spinal cord level C
6 o Triceps jerk: a tap on the tendon of triceps posterior to the elbow- tests mainly for spinal cord level C
7
With these 2 jerks, are stimulating sensory (afferent) fibres to elicit a specific motor response

Origin: from skull and spines of all cervical & thoracic vertebrae
Insertion: is inserted continuously into lateral ⅓ of the clavicle, medial border of the acromion & spine of scapula
Direction of fibers: upper fibers directed downwards and laterally; middle fibers run horizontally laterally; lower fibers directed upward and laterally
Action: upper fibers elevate clavicle & scapula as in shrugging; middle fibers retract scapula towards median plane; lower fibers depress scapula o Upper and lower fibers together rotate scapula laterally as in abduction of shoulder joint above 90˚ (acting together with the serratus anterior muscle)
Nerve supply: its motor nerve supply is from spinal part of accessory
nerve (11 th cranial nerve); its sensory innervations comes from C
3
and C
4 fibers
Clinical: injury to spinal part of the accessory nerve (11 th cranial nerve), muscle paralyzed resulting in bottle neck paralysis – abduction from 90-
180º affected; shrugging of shoulder also severely affected on paralyzed side o Paralysis of trapezius causes dropping/depression o Rotating scapula allows abduction from 90-180˚ - not done by shoulder joint because greater tubercle hits coraco-acromial arch at 90˚ o Maintains posture (erect) of neck/head
Structures under cover of trapezius: spinal part of accessory nerve, dorsal scapular nerve, suprascapular nerve, deep branch of transverse cervical artery & muscles
(levator scapulae, rhomboid minor & major, supra- & infraspinatus)
3 muscles arranged one below the other deep to trapezius
Origin: originate (medially) from cervical & thoracic vertebrae
Insertion: are inserted to medial border of scapula
Nerve supply: all 3 muscles supplied by dorsal scapular nerve (C
5
) – dorsal scapular nerve is accompanied by deep branch of transverse cervical artery
Action: levator scapulae elevates scapula; rhomboid major and minor retract scapula towards the median plane, bracing back shoulder

Triangular gap near inferior angle of scapula
Boundaries of the triangle: o Superomedially it is bounded by trapezius o Inferiorly it is bounded by superior border of latissimus dorsi o Laterally it is bounded by medial border of scapula
Floor: 6 th & 7 th ribs and the 6 th intercostal space
When arms are folded across front of chest and trunk flexed, scapulae are drawn anteriorly so that auscultatory triangle enlarges
Clinical: it is through this triangle that posterior segments of lung are examined using a stethoscope o Before advent of stethoscope, physicians used to listen to sound of cardioesophageal junction of stomach by applying their ears to this triangle on left side
It is called latissimus because it is very wide
Origin: from the iliac crest, lumbar fascia, spines of lower 6 thoracic vertebrae
Muscle winds around teres major and goes to front of it, therefore the 2 muscles, teres major and latissimus dorsi, form the posterior fold of axilla
Insertion: into floor of intertubercular sulcus (bicipital groove)
Action: helps to draw arm backwards and medially, therefore has 3 actions on arm:
1) Extension
2) Adduction
3) Medial rotation
It is ‘swimmer’s muscle’, evident in back stroke swimming – is well developed in boat rowers and canoers, and raises body toward arms during climbing or chin–ups
Nerve supply: supplied by nerve to latissimus dorsi (thoracodorsal nerve) which arises from posterior cord of brachial plexus
Clinical: when muscle is paralyzed one cannot take the pull ups over a horizontal exercise bar, but for weakness in extension and adduction there is no other appreciable disability following the paralysis of the muscle; therefore, they may sacrifice the nerve to latissimus dorsi while removing cancerous axillary lymph nodes but not the nerve to serratus anterior o Crutch cannot be used in a patient whose latissimus dorsi is paralyzed because posterior fold weak and can pres upon axillary nerve, damaging it
Called deltoid because is shaped like inverted Greek letter delta
Responsible for smooth round contour of shoulder
Principle abductor of shoulder
Overlaps upper end of humerus
Axillary nerve and posterior circumflex humeral vessels lie deep to the muscle
Its anterior and posterior fibers are unipennate, while middle fibers are multipennate and strong
Origin: lateral ⅓ of clavicle (anterior border) - anterior fibers; lateral border of acromion – middle fibers; spine of scapula - posterior fibers; origin shaped like letter “U” placed sideward
Insertion: deltoid tuberosity of humerus (V-shaped mark on middle of lateral surface of shaft of humerus)
Nerve supply: axillary nerve (C
5, 6
)
Action:
Anterior fibres- flexor, adductor and medial rotator of the arm
Middle fibres- Abductor of the arm (15°- 90°)
Posterior fibres- Extensor, adductor and lateral rotator of the arm o Deltoid is major abductor (15 – 90°) of arm – it is assisted by supraspinatus in initial 15°

abduction o When arm is by side (adducted), abduction must be initiated by supraspinatus or by leaning to side, allowing gravity to do so o Following initial 15° abduction, deltoid becomes fully effective as an abductor
Clinical: o During intramuscular injection to deltoid, care should be taken to avoid injury to axillary nerve which runs under cover of deltoid around the surgical neck of the humerus – posterior circumflex humeral artery also passes deep to deltoid o Testing function of deltoid (or axillary nerve): patient is asked to abduct arm from 15° against resistance; if acting normally, contraction of middle part of muscle can be palpated o Deltoid atrophies when axillary nerve is damaged – as deltoid atrophies, rounded contour of shoulder disappears and area below acromion on lateral side of arm appears hollow with loss of cutaneous sensation
Structures under cover of deltoid:
Boundaries:
Superior: subscapularis, fibrous capsule of shoulder joint, teres minor
Inferior: teres major
Lateral: surgical neck of humerus
Medial: long head of triceps
Structures passing: axillary nerve and posterior circumflex humeral vessels (a tumor growth in space most likely compresses both these)
Quadrangular space syndrome: hypertrophy/fibrosis of muscles forming boundaries may impinge on axillary nerve causing weakness of deltoid and atrophy of teres minor, which affects rotator cuff functions
It lies medial to the long head of triceps
AKA triangular space
Boundaries: Above: teres minor
Below: teres major
Lateral: long head of triceps
Structures passing: circumflex scapular artery & vein
Is below teres major
AKA triangular interval
Boundaries: Above: teres major

Medial: long head of triceps
Lateral: shaft of the humerus
Structures passing: radial nerve and profunda brachii vessels
Clinical: any space-occupying lesion (ex. tumor) in these spaces may compress structures passing through respective spaces
If tumour affects radial nerve, unable to extend wrist, therefore wrist drop
Origin: from posterior cord of brachial plexus, root value C
5
& C
6
Lies behind 3 rd part of axillary artery & anterior to subscapularis
Passes through quadrangular space along with posterior circumflex humeral vessels
It supplies the shoulder joint
Termination: divides into anterior and posterior branches o Anterior branch: supplies anterior part of deltoid and small area of skin over anterior part of deltoid; winds around surgical neck of humerus accompanied by posterior circumflex humeral artery o Posterior branch: supplies teres minor and deltoid and becomes superior (upper) lateral cutaneous nerve
of arm (supplies skin over deltoid); nerve to teres minor has a pseudoganglion (small swelling on nerve)
Clinical: might be injured in inferior dislocation of the shoulder joint or in the # of the surgical neck of humerus o Following injury to axillary nerve, rounded contour of shoulder is lost (paralysis of deltoid), depression below acromion and abduction is not possible from 15 to 90° range o Lateral rotation of arm is slightly affected (paralysis of teres minor) o There is also loss of cutaneous sensation on lateral aspect of shoulder o Tumour in quadrangular space results in ability to abduct should 15-90˚
Forms medial wall of the axilla
Has saw-tooth (serratus) appearance
“Boxer’s muscle”
Origin: by 8 fleshy digitations from upper 8 ribs
Insertion: to costal surface of medial border of scapula
Nerve supply: long thoracic nerve (nerve of Bell) C
5, 6, 7
, lying superficial to muscle
Action: protracts scapula (dragging it forwards) around chest wall - pushing and punching movements o This action is antagonized by contractions of rhomboids and trapezius, which act as retractors of scapula, thus paralysis of serratus anterior results in winging of the scapula
Lower fibres of serratus anterior rotate scapula forward and upward so glenoid cavity is turned up during abduction of arm above shoulder
Keeps medial border and inferior angle of scapula opposed to thoracic wall
To test serratus anterior (or the function of the long thoracic nerve), hand of outstretched limb is pushed against a wall. o When serratus anterior is paralyzed –
1. The arm cannot be raised above 90° abduction
2. There would be” winging of the scapula”
Of the shoulder joint
These are muscles which immediately surround the capsule of the shoulder joint

Following are the rotator cuff muscles: supraspinatus, infraspinatus, teres minor, subscapularis (SITS - know their nerve supply!!!)
These muscles are inserted into greater and lesser tubercles – they act like expansible ligaments and protect shoulder joint o Tonic contraction of muscles helps keep head of humerus opposed to the glenoid cavity
Rotator cuff injuries: rotator cuff tears of shoulder. 1+ rotator cuff tendons may become inflamed from overuse, aging, a fall on an outstretched hand, or a collision.
Sports requiring repeated overhead arm motion or occupations requiring heavy lifting also place a strain on rotator cuff tendons and muscles. Normally, tendons strong, but longstanding wearing down process may lead to tear. Typically, a person with a rotator cuff injury feels pain over deltoid muscle at top and outer side of the shoulder, especially when arm is raised or extended out from side of body. Motions like those involved in getting dressed can be painful.
Shoulder may feel weak, especially when trying to lift arm into a horizontal position.
Located on the dorsal surface of the scapula above the spine
Origin: from supraspinous fossa of scapula
Insertion: superior facet on greater tubercle of humerus
Nerve supply: suprascapular nerve (upper trunk of the brachial plexus - C
5, 6
)
Action: rotator cuff muscle; assists deltoid in abduction o Initiates abduction of arm from 0° -15 ° at shoulder joint
Test the function: ask patient to abduct from full-adducted position against resistance
Subacromial bursa separates tendon of supraspinatus from coraco-acromial arch and acromion process o Inflammation of the bursa is known as subacromial bursitis
Painful arc syndrome: subacromial bursitis; no pain in adducted position, but pain is felt during 50° -130° abduction when supraspinatus is in intimate contact with acromion
Note: If supraspinatus alone is torn or diseased, when patient is asked to lower fully abducted arm slowly and smoothly from
90 ° position, limb will suddenly drop to side
On the dorsal surface of the scapula below the spine
Origin: infraspinous fossa of the scapula
Insertion: to middle facet on the greater tubercle of humerus
Nerve supply: suprascapular nerve (C
5, 6
)
Action: rotator cuff muscle; lateral rotation of the arm at the shoulder joint
Origin: upper ⅔ of the lateral border of scapula, below the infraglenoid tubercle
Insertion: to the inferior facet on greater tubercle of humerus
Nerve supply: axillary nerve (C
5, 6
)
Action: rotator cuff muscle; lateral rotation of the arm
Teres minor crosses behind long head of triceps, forming the upper boundary of the quadrangular space
Lies on the costal surface of scapula. Forms the posterior wall of the axilla.

Origin: from the subscapular fossa
Insertion: lesser tubercle of humerus. It passes in front of the fibrous capsule of the shoulder joint.
Nerve supply: Upper and lower subscapular nerves (posterior cord)
Action: Rotator cuff muscle. Medial rotation and adduction of arm at the shoulder joint.
Along with latissimus dorsi, it forms the posterior fold of axilla
Crosses in front of long head of triceps, forming inferior boundary of the quadrangular space
Origin: lateral border & inferior angle of scapula.
Insertion: medial lip of intertubercular sulcus of humerus
Action: adduction, medial rotation and extension of the arm at the glenohumeral joint o It is not a part of the rotator cuff
Nerve supply: lower subscapular nerve
Test: ask the patient to adduct the abducted arm against resistance
Type: saddle type of synovial
Dislocation of this joint not common – more often leads to # of clavicle
Plane synovial
Dislocation of joint is called “shoulder separation” – not dislocation of shoulder joint tho
Scapula glides around posterolateral chest wall (if you remember which muscle is attached and where in the scapula, you can guess their action on the scapula)
Elevation: as in shrugging of shoulder; movement is carried out by upper fibers of trapezius and levator scapulae
Depression: carried out by the gravity assisted by the lower fibers of trapezius
Protraction: serratus anterior and pectoralis minor
Retraction: rhomboid muscles and middle fibers of trapezius
Lateral rotation: called lateral rotation because inferior angle of scapula moves laterally; movement is observed when hand is raised above level of head; 2 muscles help in this movement: trapezius and serratus anterior; trapezius acts like a wing-nut

Medial rotation: opposite of lateral rotation; muscles attached to medial border assisted by pectoralis minor help bring about this movement
It is region of the upper limb between the shoulder and forearm
It is divided into 2 compartments: anterior and posterior compartment
Deep fascia invests structures and sends inward 2 fascial septae: lateral and medial intermuscular septa, which are attached to lateral and medial supracondylar ridges of humerus, thus dividing arm into anterior (in front of the septae) and posterior (behind the septae) compartments
Cephalic and basilic veins run superficial to deep fascia in lower half of arm, but basilic vein pierces deep fascia in middle of arm and continues as brachial vein deep to deep fascia
Note: Muscles of anterior compartment are supplied by musculocutaneous nerve and muscles of posterior compartment are supplied by radial nerve. However, brachialis, which is a muscle of anterior compartment is supplied by both musculocutaneous and radial nerves.
Divided by lateral and medial intermuscular septa
The following muscles are in the anterior compartment of the arm:
1.
Biceps brachii
2.
Coracobrachialis * BBC
3.
Brachialis – also supplied by radial nerve, therefore hybrid muscle
Note: All 3 muscles are supplied by the musculocutaneous nerve
Major nerve of posterior arm: radial
Main nerve of forearm: median, parly ulnar
Main nerve of posterior forearm: median
Main nerve of hand: ulnar nerve, partly median
2 heads: a short and a long head
It overlaps the major vessels and nerves
Origin: o Short head: from tip of the coracoid process along with the coracobrachialis o Long head: from supraglenoid tubercle of scapula (inside capsule of the shoulder joint)
The tendon of long head of biceps is intracapsular and extrasynovial o It emerges through intertubercular groove (deep to the transverse humeral ligament) and joins short head
Insertion: inserted into posterior part of radial tuberosity (tendon) and deep fascia of forearm via bicipital aponeurosis
Nerve supply: musculocutaneous nerve
Action: crosses shoulder joint, elbow joint and superior radioulnar joint o Action on shoulder joint: long head prevents upwards dislocation of head of humerus; short head assists coracobrachialis in flexion of shoulder joint o Action on elbow joint: flexes elbow joint o Action on superior radioulnar joint: supinates forearm in a semiflexed elbow; is powerful supinator (at radioulnar joint)
Testing biceps function: in supinated position of forearm, patient asked to flex elbow joint against resistance; if acting normally, muscle forms prominent bulge on anterior aspect of the arm.
Biceps tendonitis: tendon of long head of biceps brachii moves back and forth in intertubercular sulcus, which can lead to wear and tear resulting in shoulder pain
Inflammation of tendon (bicipital tendinitis) can occur as a result of repetitive microtrauma as is common in sports involving throwing and use of racquet; tenderness and crepitus can be observed

Dislocation of tendon of long head: painful condition; during rotation of arm, sensation of popping or catching is felt
Rupture of long head: popeye deformity (a ball appears at distal arm); may occur in weight lifters
Origin: from tip of the coracoid process along with the short head of the biceps
Insertion: into the middle of the medial side of the humerus.
Action: crosses shoulder joint anteromedially, therefore it is flexor & adductor of the shoulder
Note: pierced by the musculocutaneous nerve; is a useful landmark in the middle of the arm
Nerve supply: musculocutaneous nerve
Origin: from the lower part of the front of the humerus
Insertion: into ulnar tuberosity of ulna (in front of coronoid process of ulna)
Crosses elbow in front of elbow joint, therefore powerful flexor of elbow
Action: flexes elbow joint; slowly relaxes during extension of elbow
Nerve supply: supplied by 2 nerves: musculocutaneous N and radial N – radial nerve supplies lateral part of muscle
Clinical: fracture of lower part of the shaft of the humerus may injure the brachialis attachment
Note that brachialis lies in lower part of front of arm and musculocutaneous nerve, median nerve and brachial artery lie between it and biceps brachii
It is continuation of the axillary artery in the arm
Origin: begins at level of the lower border of the teres major
Termination: opposite neck of radius by dividing into 2 terminal branches: radial (superficial) and ulnar (deep, larger)
Relations: Median nerve lies lateral to it in upper part, crosses and then lies medial to it in lower part
Ulnar nerve lies medial to the brachial artery
Branches:
1. Profunda brachii (deep artery of the arm)
2. Nutrient artery to humerus
3. Superior ulnar collateral artery
4. Inferior ulnar collateral artery
5. Muscular branches
6. Two terminal branches: radial and ulnar.
Clinical: pulsations of brachial artery are readily felt in middle of arm medial to biceps; artery is used to take the blood pressure; pulse of the brachial artery is palpable on the anterior aspect of the elbow and, with the use of a stethoscope and sphygmomanometer (blood pressure cuff) often used to measure the blood pressure. Also felt in cubital fossa.
Ideal place to compress brachial artery to control hemorrhage is middle of arm since arterial anastomoses around elbow provides adequate arterial supply to upper limb. However brachial artery has to be clamped distal to origin of deep artery of the arm (profunda brachii).

Volkmann's contracture: also known as Volkmann's ischemic contracture is permanent flexion contracture of hand at wrist, resulting in claw-like deformity of hand and fingers.
Results from ischemia of muscles of forearm. Caused by pressure, possibly from improper use of a tourniquet, improper use of a plaster cast or from compartment syndrome. Commonly described in a supracondylar fracture where it results from occlusion of the brachial artery.
Supplies the muscles of the front of the arm and skin of the lateral forearm
Origin: from the lateral cord of the brachial plexus
Its root value is C
5, 6, 7
Pierces the coracobrachialis – gives branch to it and runs deep in biceps
Supplies 3 muscles: coracobrachialis, biceps and brachialis (BBC)
Continues as lateral cutaneous nerve of forearm in roof of cubital fossa to supply skin of lateral side of forearm
Biceps reflex: deep tendon reflex (brief jerk-like flexion of the elbow) elicited at elbow by tapping on biceps tendon by a reflex hammer. Normal response indicates integrity of musculocutaneous nerve and the C5 & C6 spinal cord segments. Abnormal response indicates CNS or PNS disease.
Origin: arises by 2 roots – lateral root arises from lateral cord & medial root from medial cord of brachial plexus
Lies lateral to brachial artery in upper part & crosses superficial to artery to lie medial to it in lower part
It lies medially in the cubital fossa
Doesn’t give any muscular branch or any other named branch in arm
– may give unnamed vascular branches
In forearm: passes btw 2 heads of pronator teres to enter flexor compartment of the forearm
Supplies pronator teres before it traverses between its two heads o Hypertrophy of pronator teres causes compressiong of nerve, therefore pronator
teres syndrome
Supplies the flexor muscles of the forearm and hand and skin of the palm, directly and indirectly, except for the flexor carpi ulnaris (ulnar N) and medial half of flexor digitorum profundus (ring and little finger – ulnar N)

Origin: from medial cord of brachial plexus
It lies between the axillary artery and vein
It lies medial to brachial artery as far as insertion of coracobrachialis; later it goes far more medial and pierces medial intermuscular septum
It is accompanied by superior ulnar collateral artery; later it lies behind medial epicondyle of humerus
It enters the forearm by passing through the 2 heads of origin of the flexor carpi ulnaris
It does not give any branches in the arm
It supplies muscles of the forearm (flexor carpi ulnaris, medial ½ of flexor digitorum profundus) and hand and skin of the hand
Triceps, anconeus, axillary nerve, radial nerve, profunda brachii artery, posterior circumflex humeral artery
3 heads: o Long head: arises from infraglenoid tubercle which lies outside capsule of shoulder joint o Lateral head: arises from posterior surface of the shaft of humerus superior to radial groove o Medial head: arises from lower part of the posterior surface of humerus below radial groove
Insertion: all 3 heads join to form belly of triceps and it is inserted into olecranon process of ulna
Action: extension of the elbow
Nerve supply: radial nerve
Origin: from the back of the lateral epicondyle of the humerus
Insertion: to the ulna
Action: it moors the ulna to the radius during rotatory movements of the forearm
Nerve supply: radial nerve
Origin: from posterior cord of brachial plexus; lies behind 3 rd part of axillary artery & in front of subscapularis
Enters lower triangular space with profunda brachii vessels
Branches in axilla: posterior cutaneous nerve of arm and branch to long head of triceps
Branches in the radial groove – 3 muscular and 2 cutaneous branches:
1. Branch to lateral head of triceps
2. Branch to medial head of triceps
3. Nerve to anconeus
4. Lower lateral cutaneous nerve of arm
5. Posterior cutaneous nerve of forearm

Branches in arm after emerging from radial groove in front of arm after piercing lateral intermuscular septum: 1) lateral part of brachialis 2) brachioradialis 3) extensor carpi radialis longus
Here it lies between the brachialis and brachioradialis muscles
Clinical: injury to radial nerve in arm causes wrist drop and loss of cutaneous sensation over dorsum of hand and dorsal aspect of lateral 3½ fingers
If radial nerve damaged in axilla, extension of elbow not possible because all 3 heads damaged
If radial nerve damaged at radial groove, still some extension because long head of triceps intact
Supination still possible in both situations because, even though supinator affected, biceps still okay (supplied by musculocutaneous nerve)
Sensory loss if cut nerve at axilla in: posterior arm, lower lateral arm, posterior forearm, lateral part of dorsum of hand, lateral 3.5 fingers of arm, except skin
Termination: enters forearm where it ends by dividing into superficial and deep (posterior interosseus) branches o Superficial branch: sensory (cutaneous); injury to this branch cause sensory loss only o Posterior interosseus nerve: pierces supinator muscle (winding around neck of radius) to enter extensor compartment of forearm; motor to muscles of extensor compartment of forearm; injury to this branch causes wrist drop without loss of cutaneous sensation; hypertrophy of supinator cause ‘finger drop’ entrapping this nerve
Type: synovial – ball & socket, multiaxial
Ligaments: fibrous capsule, glenohumeral ligament (superior, middle & inferior – strengthen anterior), transverse humeral (not directly on joint; connects greater and lesser tubercles), coracohumeral ligament, glenoidal labrum
Origin of the long head of biceps is intracapsular
Muscular rotator cuff muscles keep head opposed to glenoid cavity
Lower part of fibrous capsule is loose and lax, therefore allows free movement inferiorly – thus can abduct and area prone for dislocation
Subacromial (subdeltoid) bursa is not communicated with the joint
Subscapular bursa (deep to subscapularis muscle) is continuous with the joint
Movements of the shoulder joint: flexion, extension, adduction, abduction, medial rotation, lateral rotation, circumduction
Muscles bringing about the movements: o Flexion: pectoralis major (clavicular head), deltoid (anterior part), coracobrachialis assisted by the biceps o Extension: deltoid (posterior part), teres major, latissimus dorsi, sternocostal fibers of pectoris major, long head of triceps o Abduction: supraspinatus (0-15 °), deltoid (15-90°), supraspinatus initiates abduction o Adduction: pectoralis major, latissimus dorsi, subscapularis, infraspinatus and teres minor o Medial rotation: subscapularis, pectoralis major, deltoid (ant. fibers), teres major, latissimus dorsi o Lateral rotation: infraspinatus, teres minor, deltoid
(posterior part) o Tensors of the fibrous capsule: rotator cuff muscles o Resisting down ward dislocation: deltoid with other muscles from above

Clinical anatomy of the shoulder joint:
1.
Dislocated anterioroinferiorly usually (head of humerus dislocated downwards and forwards)
2.
Supraspinatus tendinitis causes subacromial bursitis, a painful condition due to inflammation of the bursa. In such patients pain occurs during 50-130º abduction (Painful arc syndrome)
3.
Rotator cuff injuries: repeated use (eg. baseball pitchers) may allow humeral head to impinge on coracoacromial arch causing inflammation of rotator cuff resulting in degenerative tendonitis of rotator cuff
4.
Axillary nerve injury: when glenohumeral joint dislocates inferiorly
5.
Glenoidal labrum tear: may occur in baseball or football players; usually occurs in anterosuperior part of glenoidal labrum; person will feel pain while throwing; occurs when dislocated inferiorly and anterior part thrown
6.
Frozen shoulder: adhesive fibrosis and scarring (due to trauma in region) between the joint capsule, rotator cuff, and deltoid. The person will have difficulty in abducting the arm; in elderly

1.
What are dermatomes? What is its clinical significance? Which dermatome supplies – skin over the deltoid? - Middle finger?
- Little finger? - thumb? – Upper part of medial side of arm?
2.
Name & locate the prominent muscles seen on the back of the shoulder and arm?
3.
What muscles abduct shoulder from 90-180 degrees?
4.
Which muscle is responsible for shrugging of the shoulder?
5.
Accessory nerve lesion causes paralysis of which muscles?
6.
What are the effects of paralysis of trapezius muscle?
7.
Which muscles bring about bracing back of the shoulder? What nerve supplies them?
8.
What structures form the floor of the ‘triangle of Auscultation’? What is its clinical significance?
9.
Which nerve can be sacrificed while removing axillary lymph nodes?
10.
Which muscles form the posterior axillary fold? What is their action on shoulder?
11.
Which muscle is used for intramuscular injections? What care should be exercised?
12.
Which muscle abducts arm from 15-90 degrees?
13.
What happens if deltoid muscle is paralyzed?
14.
Hypertrophy of muscles forming boundaries of quadrangular space affects what structures? What is the effect? What structures pass through quadrangular space (name the nerve and the artery)?
15.
Tumor in upper or lower triangular space affects what corresponding structures?
16.
What is the origin and root value of Axillary nerve?
17.
In which pathological conditions the axillary nerve is injured?
18.
What are the effects of lesion of the axillary nerve? What is the motor loss and sensory loss of such a lesion?
19.
What degree of abduction is affected in injury to axillary nerve alone?
20.
Why lateral rotation of the arm is affected in axillary nerve injury?
21.
Why a patient with axillary nerve injury is still able to initiate abduction?
22.
Lesion of which nerve brings about winging of scapula? What is its root value?
23.
Why a patient with paralysis of serratus anterior cannot abduct arm above 90 degree?
24.
A patient is unable to perform pushing and punching movements. What muscle is paralysed?
25.
Name the rotator cuff muscles? What is the nerve supply of each of them?
26.
What is painful arc syndrome? What muscle is affected? What bursa is inflamed?
27.
Which muscles are affected by avulsion # of greater tubercle?
28.
Which muscle initiates (0-15°) abduction?
29.
What are the effects of lesion of suprascapular nerve lesion?
30.
Which muscle is affected by avulsion # of lesser tubercle? What action is affected?
31.
A patient finds difficulty in laterally rotating the arm. What muscles are injured?
32.
What are the manifestations of rotator cuff injury?
33.
What are the actions of teres major? Is it a rotator cuff muscle?
34.
What is ‘shoulder separation’
35.
What muscles bring about lateral rotation of the scapula?
36.
Which nerve supplies the muscles of the anterior compartment of the arm? Which muscle has double nerve supply?
37.
Which nerve supplies the muscles of the back of the arm?
38.
Which muscle has intracapsular origin?
39.
Which muscle is a powerful supinator of the forearm?
40.
Inflammation of which tendon causes tenderness in upper arm region?
41.
What is popeye deformity? Which structure is responsible for this?
42.
Which muscle is pierced by the musculocutaneous nerve?
43.
Which muscle is damaged by a fracture of the lower part of humerus?
44.
What is the origin and termination of the brachial artery? What are its branches?
45.
At which location brachial artery can be effectively compressed to control’? In which conditions does it occur? bleeding?
Why should it be clamped distal to the origin of profunda brachii artery?
46.
What is ‘volkman’s contracture? Compression of which artery can cause this?
47.
What is the origin of the musculocutaneous nerve? How does it terminate?
48.
What are the motor and sensory innervations of the musculocutaneous nerve? What is the effect of its lesion?
49.
What is biceps jerk? What does it test? What spinal cord segment is involved?

50.
What is the origin of the median nerve? What are its roots of origin? What is its root value? How does it enter the forearm?
Which muscle it passes through? What is the motor and sensory distribution of it?
51.
Which nerve is affected by a # of the medial epicondyle?
52.
What is the origin of the ulnar nerve? How does it enter the forearm? Which muscle it passes through to enter forearm?
What are its motor and sensory distributions?
53.
Which muscle is injured in # of the olecranon process? What is its nerve supply?
54.
What structures run in the radial groove?
55.
What nerve is involved in # of mid-shaft of humerus?
56.
What is the origin of the radial nerve? What are the two terminal branches of the radial nerve? Which terminal branch of the radial nerve is purely sensory? Which is purely motor? What do these terminal branches supply?
57.
What structures are supplied by the trunk of the radial nerve?
58.
What is wrist drop? Which nerve injury causes this? What is the sensory and motor loss in this condition? Lesion of which nerve causes wrist drop without any sensory loss?
59.
What is finger drop? Hypertrophy of which muscle cause this? And what nerve is entrapped?
60.
Lesion of which nerve causes only sensory loss on lateral side of dorsum of hand?
61.
Which part of the fibrous capsule of the shoulder joint is loose? What is the advantage and disadvantage of it?
62.
Name the muscles which bring about each movements of the shoulder joint
63.
Dislocation of shoulder occurs where? What nerve is in danger?
64.
What is ‘frozen shoulder’?
65.
What is painful arc syndrome?
66.
What are rotator cuffs & their injury?
67.
Identify the structures seen in the x-rays shown
68.
Identify the structures in the MRI picture