Upper Limb

Question 1

Adductors at the shoulder joint

Answer 1

Lady between the two majors
LD pect and teres major

Question 2

Flexors of arm, their nerve supply its root value and its name in forearm

Answer 2

Main flexors of arm at shoulder = biceps brachii + coracobrachialis + anterior deltoid (clavicular head of pec major helps)
Muculocutaneous nerve c5 c6 c7
In forearm it continues as LCN of forearm

Question 3

Extensors at the shoulder joint

Answer 3

Post fibers of deltoid
Teres major
Latismus dorsi
Long head of triceps assists

Question 4

Draw line diagram of brachial plexus

Answer 4

Roots trunks divisions cords and branches

Question 5

Branches of brachial plexus roots

Answer 5

C5 dorsal scapular and branch to phrenic nerve
C5 6 7 long thoracic nerve

Question 6

Branches from trunks

Answer 6

Only superior trunk gives branches named suprascapular nerve and nerve to subclavius

Question 7

Branches from cords

Answer 7

Lateral cord. Lateral pectoral nerve. Musculocutaneous nerve and lateral root of median nerve
Posterior cord. Upper and lower Subscapular nerve , thoracodorsal ,axillary nerve and radial nerve
Medial cord. Medial pectoral nerve, mcn of arm and forearm, medial root of median nerve and ulnar nerve

Question 8

Erb’s palsy

Answer 8

• Damage to the upper nerve roots (C5, C6)
It typically occurs due to excessive separation between head and shoulder — for example, during a fall or difficult delivery.

• Motor affection: (waiter’s tip deformity) o Paralysis of arm abductors (supraspinatus + deltoid) → arm adduction o Paralysis of arm external rotators (infraspinatus +teres minor) → arm internal rotation o Paralysis of forearm flexors and supinators (biceps, brachialis, brachioradialis) → forearm extension and pronation

• Sensory affection: loss of sensation of radial side of arm and forearm

Question 9

Klumpke’s paralysis?

Answer 9

Injury to lower trunk (C8, T1)
It usually occurs due to excessive abduction of the arm — for example, when a person catches something while falling or during breech delivery with traction on the arm.

• Motor affection: (claw hand deformity) o Paralysis of all intrinsic muscles of the hand o Paralysis of wrist flexors (except flexor carpi radialis) o Hyperextension of MCP joints with flexion of IP joints

• Sensory affection: loss of sensation over ulnar border of forearm and hand

Question 10

C5 will exit between which two vertebrae

Answer 10

C4 and C5

•	In the cervical region, spinal nerves C1–C7 exit above their corresponding vertebrae.
•	From C8 downward, nerves exit below their corresponding vertebrae.

Question 11

Rotators of scapula

Answer 11

Upward Rotation of Scapula
(needed when you abduct your arm above 90°)

Trapezius (upper fibers elevate, lower fibers depress → both rotate upward).
Serratus anterior (especially lower fibers → pulls inferior angle laterally & forward).

👉 Together, trapezius + serratus anterior form the force couple for upward rotation.

Downward Rotation of Scapula
(needed when you bring the arm back to side or behind back)

Rhomboid major & minor.
Levator scapulae.
Pectoralis minor.
Latissimus dorsi (indirectly, by pulling humerus down → scapula follows).

Question 12

External rotators of arm

Answer 12

Supraspinatus infraspinatus teres minor

Question 13

Sensory distribution of radial nerve in upper limb

Answer 13

3. Radial Nerve (C5–T1)
   Sensory distribution:

Arm:
Posterior cutaneous nerve of arm → posterior arm.
Lower lateral cutaneous nerve of arm → lateral arm (below deltoid).

Forearm:
Posterior cutaneous nerve of forearm → posterior forearm.

Hand:

Dorsolateral aspect of hand + dorsal surface of lateral 3½ fingers below nail beds

Question 14

Sensory distribution of median and ulnar nerve in upper limb

Answer 14

Median nerve
No sensory supply above wrist
Palmar surface : lateral three and a half digits and corresponding palm
Dorsal surface : nail beds of lateral three and a half digits

Ulnar nerve
palmar surface Medial 1 and ½ fingers and Corresponding medial part of the palm

Dorsum Medial 1½ fingers and corresponding dorsal surface of hand

Question 15

Brachioradialis

Answer 15

Origin (O)
Upper 2/3 of lateral supracondylar ridge of humerus.
Lateral intermuscular septum.

Insertion (I)
Lateral surface of distal radius (just proximal to styloid process).

Nerve Supply (N)
Radial nerve (C5, C6, C7) — even though it’s in the flexor compartment, it’s supplied by the radial nerve (extensor nerve).

Action (A)
Flexes the elbow joint (best when forearm is in mid-prone/semi-pronated position → like holding a glass or handshake).
Assists in pronation of supinated forearm and supination of pronated forearm to bring forearm back to mid-position.

Question 16

Serratus anterior oina

Answer 16

• Origin: Outer surfaces of upper 8 (or 9) ribs
• Insertion: Costal (anterior) surface of the medial border of scapula
• Nerve supply: Long thoracic nerve (C5, C6, C7) — “C5,6,7 raise your arms to heaven”
• Action:
• Protracts the scapula (as in pushing or punching)
• Rotates scapula upward, allowing arm elevation above 90°
• Stabilizes scapula against thoracic wall

Question 17

Rotator cuff oina

Answer 17

Subscapularis
Ventral surface of scapula — lesser tubercle of humerus

Supraspinatus
Supraspinous fossa of scapula— greater tubercle of humerus

Infraspinatus
Infraspinous fossa of scapula— greater tubercle of humerus

Teres minor
Lateral border of scapula— greater tuberosity

Nerve supply
Subscapularis. Upper and lower Subscapular nerves from posterior cord
Supraspinatus and infraspinatus. Suprascapular nerve from upper trunk
Teres minor Axillary nerve

Actions
Subscapularis internal rotation
Supraspinatus initial abduction
Supra infra and teres minor external rotation of arm

Question 18

Pectoralis major oina

Answer 18

ORIGIN
Clavicular head. From the medial half of the anterior surface of the clavicle
Sternocostal head. Anterior surface of the sternum Upper 6 costal cartilages EOA

INSERTION
Humerus lateral lip of bicipital groove

ACTIONS
Adduction and medial rotation of
the arm (the whole muscle)
• Clavicular head: flexion of the arm
• Sternocostal head: extends the flexed arm
• Acts as accessory respiratory
muscle by elevating the ribs

NERVE SUPPLY
Medial (C8-T1) and Lateral (C5-C7) pectoral nerves

Question 19

Deltoid oina

Answer 19

Deltoid

Lateral clavicle, scapula

Humerus (deltoid tuberosity)

Anterior fibres: flexion and medial rotation.

Posterior fibres: extension and lateral rotation.

Middle fibres: the major abductor of the arm (after 15°).

Axillary nerve

Question 20

Triangular interval

Answer 20

Sup. Teres major
Med. Triceps (long head)
Lat. Triceps (lateral head)

• Radial nerve
• Deep artery of arm

Question 21

Triangular space

Answer 21

Sup. Teres minor

• Inf. Teres major

• Lat. Triceps (Long head)

• Circumflex scapular artery

Question 22

Quadrangular space

Answer 22

Sup. Teres minor
Inf. Teres major
Med. Triceps (long head)
Lat. Humerus (medial border)

• Axillary nerve

• Posterior circumflex a.

Question 23

Axillary artery branches

Answer 23

I Sup. Thoracic a. Medial to serratus anterior and pectoral muscles
II Thoracoacromial a. Four branches: deltoid, acromial, pectoralis, clavicular
Lateral thoracic a. Descends to serratus anterior

III Subscapular a. (largest br.). Two branches: thoracodorsal and circumflex scapular (triangular space)
Anterior humeral circumflex a.

Blood supply to humeral head: arcuate artery lateral to bicipital groove

Posterior humeral circumflex a.

Branch in the quadrangular space accompanying the axillary nerve

Question 24

Surface marking of and structures attached to coracoid process

Answer 24

This can be felt 2 cm inferior to the junction between the middle and lateral thirds of the clavicle.

Structures attached to the coracoid process?

• Ligaments o Coracoclavicular (trapezoid, conoid) o Coracoacromial o Coracohumeral

• Muscles o Pectoralis minor (insertion) o Coracobrachialis (origin) o Short head of biceps (origin

Question 25

C5 dermatome myotome and reflex

Answer 25

• Dermatome: Lateral upper arm (over deltoid) • Myotome: Shoulder abduction (deltoid), elbow flexion (biceps) • Reflex: Biceps jerk

Question 26

T1

Answer 26

T1 • Dermatome: Medial side of upper arm (near axilla) • Myotome: Intrinsic hand muscles (finger abduction and adduction) • Reflex: None routinely tested

Question 27

C6

Answer 27

• Dermatome: Lateral forearm, thumb, and index finger • Myotome: Elbow flexion, wrist extension • Reflex: Brachioradialis (supinator) jerk

Question 28

C7

Answer 28

• Dermatome: Middle finger (palm and dorsum) • Myotome: Elbow extension (triceps), wrist flexion, finger extension • Reflex: Triceps jerk

Question 29

C8

Answer 29

• Dermatome: Medial forearm, ring and little finger • Myotome finger flexors • Reflex: Finger flexor (grip) reflex

Question 30

Clinical picture of radial nerve injury at the spiral groove?

Answer 30

• Paralysis of wrist extensors → wrist drop • Paralysis of finger extensors → finger drop • Loss of sensation in the 1st web space Reflexes- triceps preserved brachioradialis lost

Question 31

Supracondylar fracture of the humerus Associated injuries?

Answer 31

• Brachial artery injury (absent distal pulse) • Anterior interosseus nerve injury (unable to flex the interphalangeal joint of his thumb and the distal interphalangeal joint of his index finger) • Ulnar nerve injury (claw hand) • Radial nerve injury (wrist drop and finger drop)

Question 32

Ulnar nerve injury at medial epicondyle

Answer 32

• Weak wrist flexion with radial deviation (FCU paralysis). • In ulnar nerve injury at the medial epicondyle, there is ulnar claw hand but clawing is minimal because FDP to ring and little fingers is also paralyzed — this is called “ulnar paradox. • Loss of finger abduction/adduction (interossei). • Positive Froment’s sign (weak adductor pollicis). 🧠 Sensory: • Loss over medial 1½ fingers (palmar + dorsal surfaces).

Question 33

Superficial flexors of forearm

Answer 33

Pronator teres Medial epicondyle and coronoid Mid-lateral radius Pronating, flexing forearm Median nerve Flexor carpi radialis Medial epicondyle 2 nd & 3 rd MC bases Flexing wrist Median nerve Palmaris longus Medial epicondyle Palmar aponeurosis Flexing wrist Median nerve Flexor carpi ulnaris Medial epicondyle and posterior ulna Pisiform Flexing wrist Ulnar nerve Flexor digitorum superficialis Medial epicondyle, proximal anterior ulna and anterior radius Base of middle phalanges Flexing PIP joint Median nerve

Question 34

Deep flexors of forearm

Answer 34

Flexor digitorum profundus Anterior and medial ulna Base of distal phalanges Flexing DIP joint Median–anterior interosseous/ulnar nerves Flexor pollicis longus Anterior and lateral radius Base of distal phalanges Flexing IP joint,thumb Median–anterior interosseous nerve Pronator quadratus Distal ulna Volar radius Pronating hand Median–anterior interosseous nerve

Question 35

Froment sign

Answer 35

Used to test adductor policies which is supplied by ulnar nerve Patient tries to compensate by flexion of thumb using fpl to keep the piece of paper between thumb and index finger

Question 36

Superficial Extensors of forearm

Answer 36

Extensor carpi radialis longus Lateral supracondylar humerus Second metacarpal base Extending wrist Radial nerve Extensor carpi radialis brevis Lateral epicondyle of humerus Third metacarpal base Extending wrist Radial nerve Anconeus Lateral epicondyle of humerus Proximal dorsal ulna Extending forearm Radial nerve Extensor digitorum Lateral epicondyle of humerus Extensor aponeurosis Extending digits Radial–posterior interosseous nerve Extensor digiti minimi Common extensor tendon Small finger extensor expansion over P1 Extending small finger Radial–posterior interosseous nerve Extensor carpi ulnaris Lateral epicondyle of humerus Fifth metacarpal base Extending/adducting hand Radial–posterior interosseous nerve

Question 37

Deep extensors of forearm

Answer 37

Supinator Lateral epicondyle of humerus, ulna Dorsolateral radius Supinating forearm Radial–posterior interosseous nerve Abductor pollicis longus Dorsal ulna/radius First metacarpal base Abducting/extending thumb Radial–posterior interosseous nerve Extensor pollicis brevis Dorsal radius Thumb proximal phalanx base Extending thumb MCP joint Radial–posterior interosseous nerve Extensor pollicis longus Dorsolateral ulna Thumb dorsal phalanx base Extending thumb IP joint Radial–posterior interosseous nerve Extensor indicis proprius Dorsolateral ulna Index finger extensor apparatus (ulnarly) Extending index finger Radial–posterior interosseous nerve

Question 38

Cubical fossa boundaries and contents

Answer 38

Boundaries: • Superolateral: Brachioradialis muscle • Medially: Pronator teres • Floor: Brachialis Contents: (from medial to lateral) • Median nerve • Brachial artery • Biceps tendon

Question 39

Muscles of extensor compartment of forearm supplied by main trunk of radial nerve and not pin

Answer 39

Ecrl Ecrb Brachioradialis Anconeus

Question 40

Cause of clawing in ulnar nerve injury and ulnar paradox

Answer 40

Cause of clawing: Loss of medial two lumbricals → unopposed extensor digitorum (MCP hyperextension) + FDP (IP flexion) → clawing of ring & little fingers. Ulnar paradox: “The higher the lesion, the less the claw” — because in proximal injury, FDP is also paralyzed, so IP joints can’t flex → deformity less obvious.

Question 41

Clinical picture of median nerve injury at elbow

Answer 41

• Loss of forearm pronation (pronator teres & pronator quadratus). • Weak wrist flexion — wrist deviates to ulnar side (since flexor carpi ulnaris acts unopposed). Hand of benediction on attempting to make a fist (index & middle fingers can’t flex). Ape-like hand • Hyperextended thumb (paralysis of FPB) • Adducted thumb (paralysis of abductor pollicis brevis) • Flat thenar eminence • Loss of sensations from: o Lateral ⅔ of the palm of the hand o Lateral 3½ digits (palmar and distal dorsal aspect)

Question 42

Attachment of flexor retinaculum? And structures passing below it

Answer 42

• Proximal o Pisiform o Tubercle of scaphoid • Distal o Hook of hamate o Trapezium Structures passing through carpal tunnel? • 4 tendons of flexor digitorum superficialis • 4 tendons of flexor digitorum profundus • 1 tendon of flexor pollicis longus • 1 tendon of flexor carpi radialis • Median nerve.

Question 43

What is the function of intertendinous connections?

Answer 43

• Create space between extensor tendons • Redistribute force between tendons • Coordinate extension of fingers • Stabilize MCP joint

Question 44

Radial nerve and power grip

Answer 44

Radial nerve causes extension of wrist Because the flexor muscles in extension position is in a state of tension than in flexion position, so contraction in this position is more powerful

Question 45

What is extensor hood

Answer 45

A triangular aponeurosis in the dorsum of fingers by which extensor tendos insert into the phalanges

Question 46

Why sensations on the dorsal two-thirds of the hand are not completely lost in a spiral groove injury of radial nerve

Answer 46

Here’s why: • The superficial branch (which supplies the dorsum of the hand) arises above the spiral groove lesion — proximal to the site where the nerve winds around the humerus. • Therefore, this branch (and its cutaneous supply to most of the dorsum of the hand) is spared. • Only the small area between the thumb and index finger (first dorsal web space) loses sensation, because that part is supplied by the posterior cutaneous nerve of the forearm, which branches at the spiral groove itself and thus gets affected.