Upper Limb Practice Questions

Q: A patient with leprosy presents with clumsiness of the hand due to ulnar nerve involvement. Palsy of which muscle group would cause this clumsiness?

Interosseous muscles. **Explanation:** In leprosy (Hansen’s disease), the **ulnar nerve** is the most commonly involved peripheral nerve. Clumsiness of the hand in ulnar nerve palsy is primarily due to the paralysis of the **interosseous muscles** (both dorsal and palmar) and the **medial two lumbricals**. These muscles are responsible for the fine, coordinated movements of the fingers. Loss of the interossei leads to a loss of finger abduction/adduction and a weakened "precision grip," resulting in the characteristic clumsiness. **Analysis of Options:** * **Interosseous muscles (Correct):** Supplied by the deep branch of the ulnar nerve. Their paralysis leads to "guttering" (atrophy of intermetacarpal spaces) and loss of fine motor control. * **Extensor carpi ulnaris (Incorrect):** This muscle is supplied by the **posterior interosseous nerve** (a branch of the radial nerve). Its involvement would affect wrist extension and ulnar deviation, not intrinsic hand coordination. * **Abductor pollicis brevis & Opponens pollicis (Incorrect):** These are muscles of the thenar eminence, which are supplied by the **median nerve**. Their involvement would lead to "Ape thumb deformity" rather than ulnar-related clumsiness. **High-Yield Clinical Pearls for NEET-PG:** * **Ulnar Claw Hand:** Characterized by hyperextension at the MCP joints and flexion at the IP joints of the 4th and 5th digits. * **Froment’s Sign:** A positive test indicates ulnar nerve palsy due to paralysis of the **Adductor pollicis** (the patient flexes the thumb IP joint using the median nerve-supplied FPL to grip paper). * **Nerve Thickening:** In leprosy, the ulnar nerve is typically palpated just above the medial epicondyle of the humerus. * **Ulnar Paradox:** A high ulnar nerve lesion (at the elbow) results in a *less* prominent clawing than a low lesion (at the wrist) because the medial half of the FDP is also paralyzed.

Q: Which of the following is false regarding Klumpke's paralysis?

Upper trunk of brachial plexus involved. **Explanation:** Klumpke’s paralysis is a lower brachial plexus injury, typically involving the **C8 and T1 nerve roots**. It usually occurs due to hyperabduction of the arm (e.g., a person falling from a height and clutching a tree branch or during a difficult vaginal delivery with breech presentation). **Why Option D is the Correct (False) Statement:** Klumpke’s paralysis involves the **lower trunk** of the brachial plexus, not the upper trunk. Injury to the upper trunk (C5-C6) results in **Erb’s Palsy**, characterized by the "Policeman’s tip" or "Waiter's tip" hand deformity. **Analysis of Other Options:** * **Option A & B:** The T1 nerve root supplies all the **intrinsic muscles of the hand**. Paralysis of these muscles, combined with the loss of the lumbricals (which normally flex MCP joints and extend IP joints), leads to the characteristic **"Claw Hand" deformity** (hyperextension at MCP and flexion at IP joints). * **Option C:** The T1 root carries preganglionic sympathetic fibers to the eye. Damage to these fibers can result in **Horner’s Syndrome** (miosis, ptosis, anhidrosis, and enophthalmos), which is a classic clinical association with Klumpke’s palsy. **High-Yield Clinical Pearls for NEET-PG:** * **Erb’s Palsy:** C5-C6 (Upper Trunk); "Waiter's Tip" deformity; loss of abduction and external rotation. * **Klumpke’s Palsy:** C8-T1 (Lower Trunk); "Claw Hand"; associated with Horner’s Syndrome. * **Sensory Loss:** In Klumpke’s, anesthesia occurs along the ulnar border of the forearm and hand. * **Mnemonic:** **U**pper trunk = **E**rb's (**U**p/**E**ast); **L**ower trunk = **K**lumpke's (**L**ow/**K**ing).

Q: Which cervical nerve root supplies the thumb dermatome?

C6. The cutaneous innervation of the upper limb follows a specific segmental pattern (dermatomes) derived from the brachial plexus. The **C6 nerve root** is responsible for the sensory supply to the lateral aspect of the forearm and, most characteristically, the **thumb** [1]. **Why C6 is correct:** In the standard dermatomal map, C6 supplies the radial side of the forearm and the entire thumb [1]. A classic memory aid for NEET-PG is to form a "6" with your thumb and index finger; this reminds you that C6 covers these digits. **Analysis of Incorrect Options:** * **A. C5 and T1:** C5 supplies the skin over the deltoid and the lateral aspect of the upper arm (pre-axial). T1 supplies the medial aspect of the forearm and distal arm (post-axial). * **C. C7:** This nerve root typically supplies the middle finger (the "center" of the hand). * **D. C8:** This nerve root supplies the medial aspect of the hand, specifically the ring and little fingers. **High-Yield Clinical Pearls for NEET-PG:** * **Reflex Association:** C6 is also the primary root for the **Brachioradialis and Biceps reflexes**. * **Motor Supply:** C6 contributes to wrist extension. A C6 radiculopathy would present with sensory loss in the thumb and weakness in wrist extension. * **The "Hand Rule":** * Thumb = C6 * Middle finger = C7 * Little finger = C8 * **Axilla:** T2 (via the intercostobrachial nerve). * **Nipple line:** T4.

Q: A 50-year-old woman presented with numbness and weakness of the right hand. On examination, there was atrophy of the thenar eminence and hypoaesthesia in the distribution. Compression of which of the following nerves could explain the presentation?

Median Nerve. ### **Explanation** The clinical presentation of **thenar eminence atrophy** and **hypoaesthesia** (numbness) in the hand is a classic sign of **Median Nerve** compression, most commonly occurring at the wrist within the carpal tunnel (Carpal Tunnel Syndrome). **1. Why Median Nerve is Correct:** The median nerve provides motor innervation to the **LOAF** muscles (Lateral two Lumbricals, Opponens pollicis, Abductor pollicis brevis, and Flexor pollicis brevis). The latter three make up the thenar eminence. Chronic compression leads to denervation and subsequent atrophy of these muscles [1]. Sensitivities are affected in the lateral 3½ fingers and the corresponding palmar surface [1]. **2. Why Other Options are Incorrect:** * **Ulnar Nerve:** Innervates the hypothenar eminence and most intrinsic hand muscles. Injury leads to "Claw Hand" and atrophy of the interossei, not the thenar eminence [1]. * **Radial Nerve:** Primarily supplies the extensors of the forearm and wrist. Injury typically results in "Wrist Drop" and sensory loss on the dorsal aspect of the first web space. * **Axillary Nerve:** Innervates the deltoid and teres minor muscles. Injury results in loss of shoulder abduction and sensory loss over the "regimental badge" area of the lateral arm. **3. NEET-PG High-Yield Pearls:** * **Ape Thumb Deformity:** Caused by median nerve palsy, where the thumb is adducted and extended due to the loss of opponens pollicis and abductor pollicis brevis. * **Pointing Index (Benedict’s Sign):** Seen when attempting to make a fist in high median nerve palsy. * **Tinel’s Sign & Phalen’s Test:** Key clinical provocative tests used to diagnose Carpal Tunnel Syndrome. * **Palmar Cutaneous Branch:** This branch of the median nerve arises *proximal* to the carpal tunnel; therefore, sensation over the central palm is often spared in Carpal Tunnel Syndrome [1].

Q: A man is unable to hold typing paper between his index and middle fingers. Which of the following nerves was likely injured?

Ulnar nerve. ### Explanation The correct answer is **C. Ulnar nerve**. **1. Why the Ulnar Nerve is Correct:** The action described—holding a piece of paper between the fingers—is called **adduction of the fingers**. This movement is performed by the **Palmar Interossei** muscles. All interossei (both palmar and dorsal) are innervated by the **deep branch of the ulnar nerve** (C8, T1) [1]. * **Palmar Interossei (3 muscles):** Adduct the fingers (PAD). * **Dorsal Interossei (4 muscles):** Abduct the fingers (DAB). Inability to adduct the fingers results in a positive "Card Test," where the patient cannot grip a piece of paper between their extended fingers against resistance [2]. **2. Why the Other Options are Incorrect:** * **Radial Nerve:** Primarily supplies the extensors of the elbow, wrist, and fingers [1]. Injury leads to "Wrist Drop," not loss of finger adduction. * **Median Nerve:** Supplies the thenar muscles (LOAF: Lumbricals 1 & 2, Opponens pollicis, Abductor pollicis brevis, Flexor pollicis brevis) [1]. Injury affects thumb opposition and precision grip (Ape thumb deformity). * **Musculocutaneous Nerve:** Supplies the anterior compartment of the arm (Biceps, Coracobrachialis, Brachialis). Injury results in weak elbow flexion and loss of sensation on the lateral forearm. **3. High-Yield Clinical Pearls for NEET-PG:** * **Froment’s Sign:** Another test for ulnar nerve palsy. The patient compensates for a weak **Adductor Pollicis** (ulnar nerve) by using the **Flexor Pollicis Longus** (median nerve), causing the thumb's IP joint to flex when gripping paper [2]. * **Ulnar Paradox:** The higher the lesion (at the elbow), the less prominent the clawing of the fingers, because the long flexors (FDP) are also paralyzed. * **Wartenberg’s Sign:** Inability to adduct the little finger due to ulnar nerve palsy [2].

Q: Which of the following clinical signs is observed in median nerve injury?

Pointing Index. **Explanation:** The **Median Nerve** is the "nerve of precision" and the "laborer’s nerve." Injury to this nerve, particularly at or above the elbow (High Median Nerve Palsy), results in the **Pointing Index** (also known as the **Ochsner’s Clasping Test**). 1. **Why Pointing Index is Correct:** When a patient is asked to clasp their hands together, the index finger remains extended. This occurs because the median nerve [1] supplies the **Flexor Digitorum Profundus (FDP)** to the index and middle fingers and the **Flexor Digitorum Superficialis (FDS)**. Paralysis of these muscles prevents flexion of the PIP and DIP joints of the index finger, leaving it "pointing." 2. **Analysis of Incorrect Options:** * **Wristdrop:** Caused by **Radial Nerve** injury (typically at the mid-shaft of the humerus). It results from paralysis of the wrist extensors. * **Wartenberg’s Sign:** Observed in **Ulnar Nerve** palsy. It is the inability to adduct the little finger due to weakness of the 3rd palmar interosseous muscle. * **Regimental Badge Sign:** A patch of sensory loss over the lateral aspect of the shoulder (deltoid area) caused by **Axillary Nerve** injury. **High-Yield Clinical Pearls for NEET-PG:** * **Ape Thumb Deformity:** Seen in median nerve injury due to paralysis of the Thenar muscles (Opponens pollicis), leading to loss of thumb opposition. * **Benediction Deformity:** Seen when the patient attempts to make a fist; the index and middle fingers stay extended (similar mechanism to Pointing Index). * **Carpal Tunnel Syndrome:** The most common site of compression for the median nerve at the wrist [1].

Q: The axillary artery is divided into three parts by which muscle?

Pectoralis minor. The **axillary artery** is the direct continuation of the subclavian artery, beginning at the outer border of the first rib and ending at the lower border of the teres major muscle. ### Why Pectoralis Minor is Correct The **pectoralis minor muscle** crosses the axillary artery anteriorly, serving as the key anatomical landmark that divides it into three functional parts: 1. **First Part:** Proximal to the muscle (between the 1st rib and upper border of pectoralis minor). It has **one** branch. 2. **Second Part:** Posterior (deep) to the muscle. It has **two** branches. [1] 3. **Third Part:** Distal to the muscle (between the lower border of pectoralis minor and lower border of teres major). It has **three** branches. ### Why Other Options are Incorrect * **Pectoralis Major:** While it forms the anterior wall of the axilla, it does not anatomically segment the artery into three distinct parts. [1] * **Teres Major:** This muscle marks the **termination** of the axillary artery, where it becomes the brachial artery. * **Teres Minor:** This muscle forms part of the posterior wall of the axilla and is a boundary for the quadrangular and triangular spaces, but it does not divide the artery. ### High-Yield Clinical Pearls for NEET-PG * **Mnemonic for Branches:** "Save The Lions And Pity She-devils" (Superior thoracic, Thoraco-acromial, Lateral thoracic, Subscapular, Anterior circumflex humeral, Posterior circumflex humeral). * **The "Rule of Numbers":** The part number corresponds to the number of branches (1st part = 1 branch; 2nd part = 2; 3rd part = 3). * **Largest Branch:** The **subscapular artery** (from the 3rd part) is the largest branch of the axillary artery. * **Surgical Landmark:** The cords of the brachial plexus are named (Lateral, Medial, Posterior) based on their relationship to the **second part** of the axillary artery. [1]

Question 1

A patient with leprosy presents with clumsiness of the hand due to ulnar nerve involvement. Palsy of which muscle group would cause this clumsiness?

Accepted Answer

Interosseous muscles

Answer

Extensor carpi ulnaris

Answer

Abductor pollicis brevis

Answer

Opponens pollicis

Question 2

Which of the following is false regarding Klumpke's paralysis?

Accepted Answer

Upper trunk of brachial plexus involved

Answer

Claw hand deformity

Answer

Intrinsic muscles of hand involved

Answer

Horner's syndrome

Question 3

Which cervical nerve root supplies the thumb dermatome?

Accepted Answer

C6

Answer

C5 and T1

Answer

C7

Answer

C8

Question 4

A 50-year-old woman presented with numbness and weakness of the right hand. On examination, there was atrophy of the thenar eminence and hypoaesthesia in the distribution. Compression of which of the following nerves could explain the presentation?

Accepted Answer

Median Nerve

Answer

Ulnar Nerve

Answer

Radial Nerve

Answer

Axillary Nerve

Question 5

A 40-year-old male patient presented to the ER with pain and deformity in the left arm after a fall. An x-ray of the affected area was ordered. The nerve most likely involved in this condition supplies which of the following muscles?

Accepted Answer

Muscle A

Answer

Muscle B

Answer

Muscle D

Answer

Muscle C

Question 6

Which arteries form the arterial anastomosis around the shoulder?

Accepted Answer

1st part of subclavian artery with 3rd part of axillary artery

Answer

2nd part of subclavian artery with 2nd part of axillary artery

Answer

3rd part of subclavian artery with 1st part of axillary artery

Answer

3rd part of subclavian artery with 3rd part of axillary artery

Question 7

A man is unable to hold typing paper between his index and middle fingers. Which of the following nerves was likely injured?

Accepted Answer

Ulnar nerve

Answer

Radial nerve

Answer

Median nerve

Answer

Musculocutaneous nerve

Question 8

Which of the following clinical signs is observed in median nerve injury?

Accepted Answer

Pointing Index

Answer

Wristdrop

Answer

Wartenberg's Sign

Answer

Regimental badge sign

Question 9

The axillary artery is divided into three parts by which muscle?

Accepted Answer

Pectoralis minor

Answer

Pectoralis major

Answer

Teres major

Answer

Teres minor

Question 10

A 32-year-old man presents with multiple fractures of his right upper limb following a severe car crash. He underwent surgery with fixation of bony fragments using metallic plates. Five months postoperatively, he presents with the ability to abduct his arm and extend his forearm. Sensation in the forearm and hand is intact. However, his hand grasp is very weak, and he cannot extend his wrist against gravity. Which of the following nerves was most likely injured during the surgical procedure?

Accepted Answer

Radial nerve at the distal third of the humerus

Answer

Posterior cord of the brachial plexus

Answer

Radial and ulnar nerves

Answer

Radial, ulnar, and median nerves

Upper Limb — MCQs

Upper Limb — MCQs

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