Upper Limb Practice Questions

Q: All of the following muscles of the shoulder girdle assist in abduction of the upper limb, EXCEPT:

Latissimus dorsi. **Explanation:** Abduction of the shoulder is a complex movement involving multiple muscles acting in a coordinated sequence. The correct answer is **Latissimus dorsi** because it is a powerful **adductor**, extensor, and medial rotator of the humerus—actions diametrically opposed to abduction. **Analysis of Options:** * **Latissimus dorsi (Correct):** Known as the "Climber's muscle," it pulls the trunk toward the arms. Because its insertion is on the floor of the bicipital groove (anterior humerus), its contraction brings the arm toward the midline (adduction). * **Deltoid:** The multipennate middle fibers are the primary abductors of the arm from 15° to 90°. * **Supraspinatus:** This rotator cuff muscle initiates the first 0–15° of abduction. It also stabilizes the humeral head in the glenoid cavity, providing a fulcrum for the deltoid. * **Long head of biceps brachii:** While primarily a flexor of the elbow and supinator, its tendon passes over the head of the humerus. When the arm is laterally rotated, it acts as a weak accessory abductor and helps stabilize the glenohumeral joint. **NEET-PG High-Yield Pearls:** 1. **The Abduction Sequence:** * 0–15°: Supraspinatus (Suprascapular nerve). * 15–90°: Deltoid (Axillary nerve). * >90° (Overhead): Serratus anterior and Trapezius (Scapular rotation). 2. **The "Lady between two Majors":** Latissimus dorsi inserts into the bicipital groove between the Pectoralis major (lateral lip) and Teres major (medial lip). All three are adductors. 3. **Clinical Correlation:** In a Supraspinatus tear, the patient cannot initiate abduction and may lean toward the affected side to use gravity to "jumpstart" the deltoid's range.

Q: What is the deformity caused by the involvement of the 1st and 2nd lumbrical muscles called?

Median claw hand. ### Explanation **1. Why Median Claw Hand is Correct:** The **1st and 2nd lumbricals** are innervated by the **Median nerve** [1]. The physiological role of lumbricals is to flex the metacarpophalangeal (MCP) joints and extend the interphalangeal (IP) joints ("L-shaped" position). When these muscles are paralyzed (typically due to a distal median nerve lesion), the antagonistic muscles take over, resulting in the opposite posture: **hyperextension at the MCP joints and flexion at the IP joints** of the index and middle fingers. This specific deformity is known as the **Median claw hand**. **2. Analysis of Incorrect Options:** * **A. Ulnar claw hand:** Caused by paralysis of the **3rd and 4th lumbricals** (and all interossei) due to ulnar nerve injury [1]. It affects the ring and little fingers. * **C. Total claw hand:** Occurs when there is a combined lesion of both the **Median and Ulnar nerves** (or a Klumpke’s paralysis/C8-T1 injury), leading to clawing of all four fingers. * **D. Pointing finger (Ochsner’s clasping test):** This occurs in **proximal** median nerve injuries. When the patient attempts to make a fist, the index and middle fingers remain extended due to loss of the Long Flexors (FDS and lateral half of FDP), not just the lumbricals. **3. Clinical Pearls for NEET-PG:** * **Lumbrical Innervation:** Remember the **"12-23" rule**: 1st and 2nd lumbricals = Median nerve; 3rd and 4th lumbricals = Ulnar nerve [1]. * **The Paradox:** Clawing is more prominent in **distal** lesions (at the wrist) than proximal lesions because the long flexors (FDP) remain intact and pull the IP joints into deeper flexion. * **Ape Thumb Deformity:** Also caused by median nerve injury, specifically due to paralysis of the *Abductor Pollicis Breis*, leading to loss of thumb opposition [1].

Q: A 13-year-old boy is brought to the emergency department after losing control during a motorbike race in which he was run over by several of the other racers. Physical examination reveals several cuts and bruises. He is unable to extend the left wrist, fingers, and thumb, although he can extend the elbow. Sensation is lost in the lateral half of the dorsum of the left hand. Which of the following nerves has most likely been injured, and in what part of the arm is the injury located?

Radial nerve, midhumerus. ### Explanation **1. Why the Correct Answer is Right:** The clinical presentation describes **Wrist Drop** (inability to extend the wrist, fingers, and thumb) with preserved elbow extension. This indicates an injury to the **Radial Nerve** distal to the origin of the branches to the Triceps brachii. [1] The radial nerve enters the **spiral groove** of the humerus (midshaft), where it is highly vulnerable to fractures or direct trauma. [2] At this level, the branches to the long and medial heads of the triceps have already departed (preserving elbow extension), but the branches to the brachioradialis, extensor carpi radialis longus, and the posterior interosseous nerve (which supplies the finger/thumb extensors) are affected. [1] The sensory loss in the **lateral half of the dorsum of the hand** (first dorsal web space) confirms radial nerve involvement. **2. Why the Other Options are Wrong:** * **Options A & B (Median Nerve):** Median nerve injury typically presents with "Ape Hand" deformity, loss of thumb opposition, and sensory loss on the palmar aspect of the lateral 3.5 digits. It does not control wrist or finger extension. [1] * **Option D (Ulnar Nerve):** Ulnar nerve injury leads to "Claw Hand" (at the wrist) and sensory loss on the medial 1.5 digits. It does not cause wrist drop. [1] **3. Clinical Pearls for NEET-PG:** * **High-Yield Rule:** The higher the radial nerve lesion, the more "drop" you see. * **Axilla:** Loss of elbow extension + Wrist drop. * **Spiral Groove (Midhumerus):** Normal elbow extension + Wrist drop + Sensory loss. * **Posterior Interosseous Nerve (PIN):** Finger drop ONLY; **No** sensory loss and **No** true wrist drop (ECRL is spared). * **Saturday Night Palsy:** Compression of the radial nerve in the spiral groove, presenting identically to this case. * **Holstein-Lewis Fracture:** A fracture of the distal third of the humerus resulting in radial nerve palsy. [2]

Q: At what age does the radial head ossify?

4 years. The ossification of the elbow joint is a high-yield topic for NEET-PG, typically remembered using the mnemonic CRITOE, which represents the chronological order of appearance of the secondary ossification centers. 1. Capitellum: 1 year 2. Radial Head: 4 years (Correct Answer) 3. Internal (Medial) Epicondyle: 5–6 years 4. Trochlea: 9–10 years 5. Olecranon: 10 years 6. External (Lateral) Epicondyle: 11–12 years Why Option B is correct: The secondary ossification center for the head of the radius typically appears at 4 years of age (range 3–5 years). It eventually fuses with the shaft of the radius at puberty (approximately 15–17 years). Analysis of Incorrect Options: * Option A (2 years): At this age, only the capitellum is usually visible. The radial head has not yet begun to ossify. * Option C (6 years): By age 6, the medial epicondyle has usually appeared. While the radial head is visible on X-ray by this time, it first appears earlier, at age 4. * Option D (10 years): This age corresponds to the appearance of the trochlea and the olecranon process. Clinical Pearls for NEET-PG: * CRITOE Mnemonic: Always remember the sequence 1-3-5-7-9-11 (approximate ages in years) to identify elbow ossification centers on pediatric X-rays. * Pulled Elbow (Nursemaid’s Elbow): This involves subluxation of the radial head through the annular ligament, common in children aged 1–4 years (before the radial head is fully formed and ossified). * Fracture Identification: Knowledge of these ages is crucial to avoid mistaking a normal ossification center for an avulsion fracture in pediatric trauma cases.

Q: A teenager is struck on the back of her carpals by a sharp-edged flying wedge while watching her boyfriend split wood. Her extensor digitorum tendons are exposed, though not severed, indicating that the surrounding synovial sheath has been opened. What other muscle has its tendon surrounded by the same synovial sheath?

Extensor indicis. ### Explanation The key to solving this question lies in understanding the **Extensor Compartments of the Wrist**. The extensor tendons pass deep to the extensor retinaculum, where they are organized into six distinct osteofascial compartments, each lined by a synovial sheath to reduce friction. **The Correct Answer: D. Extensor indicis** The **fourth compartment** of the wrist contains five tendons: the four tendons of the **Extensor Digitorum (ED)** and the single tendon of the **Extensor Indicis (EI)**. Because they share the same anatomical space and are enclosed within a single, common synovial sheath, an injury that opens the sheath of the extensor digitorum will inherently involve the sheath of the extensor indicis. **Analysis of Incorrect Options:** * **A & B (ECRB and ECRL):** These tendons are located in the **second compartment** [1]. They have their own separate synovial sheath and are separated from the fourth compartment by the dorsal tubercle of the radius (Lister’s tubercle). * **C (Extensor digiti minimi):** This tendon is located in the **fifth compartment**, situated just superficial to the distal radioulnar joint. It possesses its own independent synovial sheath. **NEET-PG High-Yield Pearls:** * **Compartment 1:** Abductor pollicis longus & Extensor pollicis brevis (Involved in De Quervain’s Tenosynovitis) [1]. * **Compartment 2:** ECRL & ECRB [1]. * **Compartment 3:** Extensor pollicis longus (Loops around Lister’s tubercle). * **Compartment 4:** ED & EI (Shared sheath). * **Compartment 5:** Extensor digiti minimi. * **Compartment 6:** Extensor carpi ulnaris. * **Mnemonic:** "2-2-1-5-1-1" (Number of tendons in compartments 1 through 6).

Q: At the end of 1 year of age, what is the number of carpal bones typically visible on a skiagram of the hand?

Two. **Explanation:** The ossification of carpal bones follows a predictable chronological sequence, making them excellent indicators for assessing skeletal maturity (bone age) in pediatric patients. At birth, the carpal bones are entirely cartilaginous and therefore not visible on a radiograph (skiagram). **Why Option C is correct:** The carpal bones ossify in a clockwise or counter-clockwise direction starting from the **Capitate**, followed by the **Hamate**. * **Capitate:** Typically appears at **1–3 months**. * **Hamate:** Typically appears at **2–4 months**. By the end of the 1st year, these are the only two carpal bones that have usually undergone sufficient ossification to be visible on an X-ray. **Analysis of Incorrect Options:** * **A. None:** Incorrect, as the Capitate and Hamate ossify within the first few months of life. * **B. One:** Incorrect, as both the Capitate and Hamate are visible by 6 months of age. * **D. Three:** Incorrect, as the third bone (**Triquetral**) typically appears at **2–3 years** of age. **NEET-PG High-Yield Facts:** 1. **Sequence of Ossification:** Remember the mnemonic "**C**apitate, **H**amate, **T**riquetral, **L**unate, **S**caphoid, **T**rapezium, **T**rapezoid, **P**isiform" (roughly follows the age in years, except for the last few). 2. **Order of Appearance:** * 1 year: 2 bones (Capitate, Hamate) * 3 years: 3 bones (Triquetral) * 4 years: 4 bones (Lunate) * 5 years: 5-6 bones (Scaphoid, Trapezium, Trapezoid) * 12 years: 8 bones (Pisiform is the last to ossify). 3. **Clinical Pearl:** The **Capitate** is the first carpal bone to ossify, while the **Pisiform** (a sesamoid bone) is the last. Bone age is usually determined by an X-ray of the **left hand and wrist**.

Q: A patient diagnosed with leprosy with ulnar nerve involvement presents with clumsiness of hand. Clumsiness is due to palsy of which of the following muscles?

Interosseous muscle. The ulnar nerve is often referred to as the **"Musician’s Nerve"** because it controls the fine, coordinated movements of the fingers. The "clumsiness" of the hand in ulnar nerve palsy—common in leprosy—is primarily due to the paralysis of the **Interosseous muscles** (both dorsal and palmar). **Why Interossei are the cause:** The interossei are responsible for abduction (DAB) and adduction (PAD) of the fingers [1]. More importantly, they work with the lumbricals to perform the "Z-movement" (flexion at MCP joints and extension at IP joints). Loss of these muscles results in a loss of fine motor control, weakness in grip, and the inability to perform intricate tasks, leading to clinical clumsiness. **Analysis of Incorrect Options:** * **Extensor carpi ulnaris (A):** Supplied by the **Posterior Interosseous Nerve** (a branch of the Radial nerve). Its palsy leads to weak wrist extension and radial deviation, not finger clumsiness. * **Abductor pollicis brevis (B) & Opponens pollicis (C):** These are **Thenar muscles** supplied by the **Median nerve** [1]. Their involvement (e.g., in Carpal Tunnel Syndrome) leads to loss of thumb opposition and abduction ("Ape thumb deformity"), rather than generalized finger clumsiness. **High-Yield Clinical Pearls for NEET-PG:** * **Ulnar Paradox:** The higher the lesion (at the elbow), the less prominent the clawing, because the medial half of the Flexor Digitorum Profundus (FDP) is also paralyzed. * **Froment’s Sign:** Tests for Adductor Pollicis (ulnar nerve) palsy; the patient flexes the thumb IP joint (using the Median nerve's FPL) to grip paper. * **Wartenberg’s Sign:** Inability to adduct the little finger due to palmar interosseous weakness.

Q: The interosseous recurrent artery is a branch of which artery?

Posterior interosseous artery. **Explanation:** The **interosseous recurrent artery** is a key vessel involved in the arterial anastomosis around the elbow joint. It arises from the **posterior interosseous artery** (a branch of the common interosseous artery) near its origin. It ascends posteriorly to the lateral epicondyle of the humerus, where it anastomoses with the middle collateral artery (a branch of the profunda brachii). **Analysis of Options:** * **Posterior Interosseous Artery (Correct):** This artery passes backward between the radius and ulna. Its first major branch is the interosseous recurrent artery, which travels upward to participate in the elbow anastomosis. * **Anterior Interosseous Artery:** This artery travels down the anterior surface of the interosseous membrane. While it pierces the membrane to join the posterior compartment near the wrist, it does not give off the recurrent branch at the elbow. * **Common Interosseous Artery:** This is a short branch of the ulnar artery that divides into the anterior and posterior interosseous arteries. While it is the "parent" vessel, the recurrent branch specifically originates from the posterior division. * **Radial Artery:** The radial artery gives off the **radial recurrent artery**, which anastomoses with the radial collateral artery. It is distinct from the interosseous system. **High-Yield Facts for NEET-PG:** * **Elbow Anastomosis Rule:** Remember that "Recurrent" arteries (from below) meet "Collateral" arteries (from above). * **Middle Collateral Artery:** This is the specific partner for the interosseous recurrent artery. * **Common Interosseous Artery:** It is a branch of the **Ulnar Artery**, not the radial artery. * **Posterior Interosseous Nerve (PIN):** While the artery passes *above* the interosseous membrane, the PIN (deep branch of radial nerve) passes through the supinator muscle to enter the posterior compartment.

Question 1

A 48-year-old female piano player presented with numbness and tingling in her left hand. She was diagnosed with carpal tunnel syndrome and underwent an endoscopic nerve release. Two weeks postoperatively, she developed profound weakness in her thumb with loss of thumb opposition. Sensation to the hand was unaffected. Which of the following nerves was injured during the operation?

Accepted Answer

Recurrent branch of median nerve

Answer

The first common digital branch of the median nerve

Answer

The second common digital branch of the median nerve

Answer

Deep branch of the ulnar nerve

Question 2

All of the following muscles of the shoulder girdle assist in abduction of the upper limb, EXCEPT:

Accepted Answer

Latissimus dorsi

Answer

Deltoid

Answer

Supraspinatus

Answer

Long head of biceps brachii

Question 3

What is the deformity caused by the involvement of the 1st and 2nd lumbrical muscles called?

Accepted Answer

Median claw hand

Answer

Ulnar claw hand

Answer

Total claw hand

Answer

Pointing finger

Question 4

A 13-year-old boy is brought to the emergency department after losing control during a motorbike race in which he was run over by several of the other racers. Physical examination reveals several cuts and bruises. He is unable to extend the left wrist, fingers, and thumb, although he can extend the elbow. Sensation is lost in the lateral half of the dorsum of the left hand. Which of the following nerves has most likely been injured, and in what part of the arm is the injury located?

Accepted Answer

Radial nerve, midhumerus

Answer

Median nerve, anterior wrist

Answer

Median nerve, arm

Answer

Ulnar nerve, midlateral forearm

Question 5

Which of the following is NOT a feature of anterior interosseous nerve (AIN) syndrome?

Accepted Answer

There is sensory loss on the medial 2 fingers.

Answer

Inability to perform OK-sign (approximate thumb and tip of index finger).

Answer

AIN is entrapped under pronator teres, flexor digitorum profundus, and flexor carpi radialis.

Answer

Conservative treatment is generally preferred, with surgery rarely indicated.

Question 6

At what age does the radial head ossify?

Accepted Answer

4 years

Answer

2 years

Answer

6 years

Answer

10 years

Question 7

A teenager is struck on the back of her carpals by a sharp-edged flying wedge while watching her boyfriend split wood. Her extensor digitorum tendons are exposed, though not severed, indicating that the surrounding synovial sheath has been opened. What other muscle has its tendon surrounded by the same synovial sheath?

Accepted Answer

Extensor indicis

Answer

Extensor carpi radialis brevis

Answer

Extensor carpi radialis longus

Answer

Extensor digiti minimi

Question 8

At the end of 1 year of age, what is the number of carpal bones typically visible on a skiagram of the hand?

Accepted Answer

Two

Answer

None

Answer

One

Answer

Three

Question 9

A patient diagnosed with leprosy with ulnar nerve involvement presents with clumsiness of hand. Clumsiness is due to palsy of which of the following muscles?

Accepted Answer

Interosseous muscle

Answer

Extensor carpi ulnaris

Answer

Abductor pollicis brevis

Answer

Opponens pollicis

Question 10

The interosseous recurrent artery is a branch of which artery?

Accepted Answer

Posterior interosseous artery

Answer

Anterior interosseous artery

Answer

Common interosseous artery

Answer

Radial artery

Upper Limb — MCQs

Upper Limb — MCQs

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