Upper Limb Practice Questions

Q: For which of the following nerve palsies is the below test detected?

Ulnar nerve. ***Ulnar nerve*** - **Froment's sign** is positive when there is weakness of the **adductor pollicis muscle**, which is innervated by the deep branch of the ulnar nerve. - Compensatory flexion of the **flexor pollicis longus (FPL)** occurs to maintain grip strength, causing thumb flexion at the interphalangeal joint. *Median nerve* - The median nerve primarily innervates the **thenar muscles** (abductor pollicis brevis, flexor pollicis brevis, opponens pollicis) and does not supply the adductor pollicis. - Median nerve palsy would present with **ape hand deformity** and loss of thumb opposition, not Froment's sign. *Radial nerve* - The radial nerve innervates **extensor muscles** of the wrist and fingers, not the adductor pollicis muscle. - Radial nerve palsy causes **wrist drop** and inability to extend the wrist and fingers, unrelated to thumb adduction testing. *Anterior interosseous nerve* - This nerve is a branch of the median nerve that innervates the **flexor pollicis longus**, **flexor digitorum profundus** (index and middle fingers), and **pronator quadratus**. - Anterior interosseous nerve palsy affects the **pincer grip** but does not cause weakness of thumb adduction tested by Froment's sign.

Q: A patient presents with a deep stab wound in the middle of the forearm, resulting in impaired movement of the thumb. Examination suggests a lesion of the anterior interosseous nerve. Which of the following muscles is paralyzed?

Flexor digitorum profundus and pronator quadratus. ### Explanation The **Anterior Interosseous Nerve (AIN)** is a purely motor branch of the **Median Nerve**. It arises in the proximal forearm, passes between the two heads of the pronator teres, and descends on the anterior surface of the interosseous membrane. **1. Why the Correct Answer is Right:** The AIN supplies exactly **2.5 muscles** in the deep compartment of the forearm: * **Flexor Pollicis Longus (FPL):** Responsible for flexion of the thumb IP joint. * **Pronator Quadratus (PQ):** The chief initiator of forearm pronation. * **Flexor Digitorum Profundus (FDP) - Lateral Half:** Specifically the tendons going to the index and middle fingers. Therefore, a lesion of the AIN leads to paralysis of the FDP (lateral half) and the Pronator Quadratus. **2. Analysis of Incorrect Options:** * **Option A & B:** These include the **Flexor Pollicis Brevis** and **Opponens Pollicis**. These are **intrinsic muscles of the hand** (thenar eminence) supplied by the recurrent branch of the median nerve, not the AIN [1]. * **Option D:** The **Flexor Digitorum Superficialis (FDS)** is supplied by the main trunk of the Median Nerve, not its anterior interosseous branch. **3. Clinical Pearls for NEET-PG:** * **Kiloh-Nevin Syndrome:** This is an isolated AIN palsy. Patients cannot make the **"OK" sign**; instead of a circle, they form a "pinch" (flat-to-flat) because they cannot flex the IP joint of the thumb (FPL) and the DIP joint of the index finger (FDP). * **Sensory Sparing:** Since the AIN is a purely motor nerve, there is **no sensory loss** in the hand, which helps differentiate it from a proximal median nerve injury [1]. * **The "Half" Rule:** Remember that the medial half of the FDP (ring and little fingers) is supplied by the **Ulnar Nerve**.

Q: Which of the following muscles is spared when the radial nerve is injured in the radial groove?

Long head of triceps. **Explanation:** The radial nerve arises from the posterior cord of the brachial plexus ($C5-T1$). To answer this question, one must understand the sequential branching pattern of the radial nerve as it descends the arm. **1. Why the Long Head of Triceps is spared:** The radial nerve gives off branches to the **long head of the triceps** and the **medial head (superior part)** high up in the axilla, *before* the nerve enters the spiral (radial) groove. Therefore, a fracture of the humeral shaft or a compression injury within the radial groove occurs distal to the origin of these fibers, leaving the long head of the triceps functional [1]. **2. Analysis of Incorrect Options:** * **Lateral head of triceps:** The branch to the lateral head arises *within* the radial groove. It is typically paralyzed in this injury. * **Medial head of triceps:** While the medial head receives a "high" branch in the axilla, its main innervation (inferior part) occurs within the radial groove. Thus, it is significantly weakened. * **Anconeus:** The nerve to the anconeus arises from the radial nerve while it is in the radial groove and descends through the medial head of the triceps to reach the muscle. It is consistently affected in spiral groove injuries. **Clinical Pearls for NEET-PG:** * **"Saturday Night Palsy":** Injury in the radial groove leads to **Wrist Drop** (loss of extensors) but **Extension of the Elbow is preserved** (due to the spared long head). * **Axillary Injury (Crutch Palsy):** If the nerve is injured in the axilla, the long head is also lost, resulting in the inability to extend the elbow. * **Sensory Loss:** In a radial groove injury, there is sensory loss over the narrow strip of the posterior forearm and the dorsal surface of the lateral $3\frac{1}{2}$ fingers. [1]

Q: Regarding the axilla, which of the following statements is accurate?

Pectoralis major and minor contribute to the anterior wall.. ### Explanation **1. Why Option A is Correct:** The axilla is a pyramid-shaped space between the upper arm and the thorax. The **anterior wall** is formed by the **Pectoralis major** (superficial layer), the **Pectoralis minor**, and the **Subclavius** muscle (deep layer) [1]. The clavipectoral fascia encloses the subclavius and pectoralis minor, further reinforcing this wall. **2. Why the Other Options are Incorrect:** * **Option B:** The **long thoracic nerve** (Nerve of Bell) runs on the **medial wall** of the axilla, specifically on the superficial surface of the serratus anterior muscle. It does not run on the posterior wall. * **Option C:** The posterior wall is formed by the Subscapularis (upper part), Latissimus dorsi, and **Teres major** (lower part). The **Teres minor** does not contribute to the axillary walls; it is part of the rotator cuff and lies superior to the axillary space. * **Option D:** The axillary artery, axillary vein, and cords of the brachial plexus are all contained **within** the axillary sheath (a derivation of the prevertebral fascia). The artery does not lie anterior to it. **3. Clinical Pearls & High-Yield Facts for NEET-PG:** * **Apex of Axilla (Cervico-axillary canal):** Bound by the clavicle (anterior), superior border of the scapula (posterior), and outer border of the 1st rib (medial). * **Contents:** The axillary artery is divided into three parts by the **Pectoralis minor** muscle, which serves as the key landmark [1]. * **Surgical Importance:** During axillary lymph node dissection (e.g., for breast cancer), the **long thoracic nerve** and the **thoracodorsal nerve** (supplying latissimus dorsi) must be preserved to avoid "winged scapula" and weakness in arm adduction/extension, respectively [1].

Q: Which dermatome corresponds to the middle finger?

C7. **Explanation:** The cutaneous innervation of the upper limb follows a specific segmental pattern derived from the brachial plexus (C5-T1). The **C7 dermatome** is responsible for the sensory supply to the **middle finger** [1]. It typically encompasses the central portion of the posterior forearm and the middle finger (both palmar and dorsal surfaces). **Analysis of Options:** * **C7 (Correct):** This is the "central" dermatome of the hand [1]. In clinical practice, testing sensation on the pad of the middle finger is the standard method to assess the C7 nerve root. * **C5 (Incorrect):** This dermatome supplies the lateral (radial) aspect of the arm, specifically over the deltoid muscle and the lateral side of the upper arm. * **C4 (Incorrect):** This supplies the skin over the "cape" area of the shoulder and the root of the neck (supraclavicular region). * **C2 (Incorrect):** This is a cranial/cervical dermatome supplying the back of the head and the area behind the ear; it does not extend to the limbs. **High-Yield Clinical Pearls for NEET-PG:** * **The "Hand Rule":** To remember hand dermatomes, use the three-finger rule: **C6** (Thumb/Radial side), **C7** (Middle finger), and **C8** (Little finger/Ulnar side). * **T1 & T2:** T1 supplies the medial forearm, while T2 supplies the medial upper arm and axilla. * **Clinical Correlation:** A herniated disc at the **C6-C7 level** typically compresses the **C7 nerve root**, leading to pain or numbness radiating specifically to the middle finger and weakness in elbow extension (Triceps).

Q: Damage to the C7 nerve root causes weakness of which of the following movements?

Wrist flexion. **Explanation:** The **C7 nerve root** is the most commonly involved root in cervical radiculopathy. It provides the primary motor supply to the **triceps** (elbow extension) and the **flexor carpi radialis** (wrist flexion). Therefore, damage to C7 leads to weakness in wrist flexion and elbow extension, along with a diminished triceps reflex. **Analysis of Options:** * **Wrist flexion (Correct):** Primarily mediated by the C7 nerve root (via the flexor carpi radialis). While C6 also contributes, C7 is the dominant segmental innervation for this movement. * **Elbow flexion (Incorrect):** This is primarily mediated by the **C5 and C6** nerve roots (musculocutaneous nerve supplying the biceps and brachialis). * **Supination (Incorrect):** This is primarily a function of the biceps brachii (**C5, C6**) and the supinator muscle (**C6**). * **Finger abduction (Incorrect):** This is a function of the dorsal interossei, which are innervated by the ulnar nerve, specifically the **T1** nerve root (and partly C8). **NEET-PG High-Yield Pearls:** * **C5:** Deltoid (Shoulder abduction), Biceps reflex. * **C6:** Biceps (Elbow flexion), Brachioradialis reflex, "Wrist drop" if radial nerve is affected at this level. * **C7:** Triceps (Elbow extension), Wrist flexors, Triceps reflex. * **C8:** Finger flexors (Grip strength). * **T1:** Interossei (Finger abduction/adduction). * **Clinical Tip:** C7 sensory loss typically presents as numbness in the **middle finger**.

Q: Which of the following movements of the thumb is lost in ulnar nerve injury?

Adduction. The correct answer is **Adduction**. The thumb's adduction is performed by the **Adductor Pollicis** muscle [1]. Unlike most other muscles of the thenar eminence, the Adductor Pollicis is supplied by the **Deep Branch of the Ulnar Nerve (C8, T1)** [1]. Therefore, in an ulnar nerve injury, this specific movement is lost. **Analysis of Options:** * **Opposition (A):** This is primarily performed by the **Opponens Pollicis**, which is supplied by the **Recurrent Branch of the Median Nerve** [1]. * **Extension (B):** Thumb extension is performed by the **Extensor Pollicis Longus and Brevis**, both of which are supplied by the **Posterior Interosseous Nerve (a branch of the Radial Nerve)** [1]. * **Abduction (D):** Abduction is performed by the **Abductor Pollicis Brevis** (Median Nerve) and **Abductor Pollicis Longus** (Radial Nerve) [1]. **Clinical Pearls for NEET-PG:** 1. **Froment’s Sign:** When a patient with ulnar nerve palsy tries to grip a piece of paper between the thumb and index finger, they cannot adduct the thumb. Instead, they flex the thumb at the interphalangeal joint using the **Flexor Pollicis Longus** (Median nerve) to compensate. This is a classic diagnostic sign. 2. **The "1.5" Rule:** The ulnar nerve supplies all intrinsic muscles of the hand *except* the **LOAF** muscles (Lateral two Lumbricals, Opponens pollicis, Abductor pollicis brevis, and Flexor pollicis brevis), which are supplied by the Median nerve [1]. 3. **Ulnar Paradox:** A high ulnar nerve lesion (at the elbow) results in a less prominent claw hand than a low lesion (at the wrist) because the long flexors (FDP) are also paralyzed, reducing the flexion of the fingers.

Q: The musculocutaneous nerve is a branch of which part of the brachial plexus?

Lateral cord. **Explanation:** The **musculocutaneous nerve (C5–C7)** is a terminal branch of the **lateral cord** of the brachial plexus. The lateral cord is formed by the union of the anterior divisions of the upper (C5-C6) and middle (C7) trunks. It typically pierces the coracobrachialis muscle and provides motor innervation to the anterior compartment of the arm (Biceps brachii, Coracobrachialis, and Brachialis) before continuing as the lateral cutaneous nerve of the forearm. **Analysis of Options:** * **Root (Option A):** Roots (C5-T1) give rise to nerves like the Long Thoracic and Dorsal Scapular nerves, but not terminal branches of the arm. * **Medial Cord (Option B):** This cord gives rise to the Ulnar nerve, Medial Cutaneous nerves of the arm/forearm, and the medial head of the Median nerve. * **Posterior Cord (Option D):** This cord gives rise to the Axillary and Radial nerves (mnemonic: **ULTRA** – Upper subscapular, Lower subscapular, Thoracodorsal, Radial, Axillary). **NEET-PG High-Yield Pearls:** 1. **The "M" Shape:** The musculocutaneous nerve forms the lateral limb of the characteristic "M" shape seen over the third part of the axillary artery. 2. **Clinical Deficit:** Injury to this nerve results in the loss of forearm flexion (biceps/brachialis) and loss of sensation along the lateral aspect of the forearm. 3. **The "BBC" Nerve:** A simple mnemonic for the muscles it supplies: **B**iceps brachii, **B**rachialis, and **C**oracobrachialis. 4. **Median Nerve Origin:** Remember that the Median nerve is unique because it receives contributions from *both* the lateral and medial cords.

Q: Which maneuver is used to test for integrity of the long thoracic nerve?

Raising the arm above the head. **Explanation:** The **Long Thoracic Nerve** (C5, C6, C7) supplies the **Serratus Anterior** muscle. The primary functions of this muscle are protraction of the scapula and, crucially, **upward rotation of the glenoid cavity**. This upward rotation is essential for abducting the arm beyond 90 degrees. Therefore, asking a patient to **raise their arm above their head** (overhead abduction) is the definitive clinical test for the integrity of this nerve. **Analysis of Options:** * **Option A (Touching opposite shoulder):** This involves adduction and internal rotation, primarily testing the Pectoralis major and Subscapularis, not the Serratus anterior. * **Option B (Shoulder shrug):** This tests the **Trapezius** muscle, which is supplied by the **Spinal Accessory Nerve (CN XI)**. * **Option D (Lifting an object):** This primarily involves the Biceps brachii, Brachialis, and back extensors; it is not a specific test for the long thoracic nerve. **Clinical Pearls for NEET-PG:** * **Winging of Scapula:** Damage to the long thoracic nerve (often during radical mastectomy or chest tube insertion) causes the medial border of the scapula to protrude posteriorly, especially when the patient pushes against a wall. * **Mnemonic:** "C5, 6, 7 raise your arms to heaven" (refers to the nerve roots and the action of overhead abduction). * **Saltatorial Nerve:** The long thoracic nerve is also known as the "Nerve of Bell." * **Dual Action:** The Serratus anterior is often called the "Boxer’s muscle" because it is the main protractor of the scapula used during punching.

Q: The radial styloid process gives attachment to which of the following muscles?

Brachioradialis. Explanation: The **radial styloid process** is a conical projection on the lateral aspect of the distal radius. It serves as the insertion point for the **Brachioradialis** muscle. **1. Why Brachioradialis is correct:** The Brachioradialis is a unique muscle of the posterior compartment of the forearm. Unlike most extensors, it acts as a flexor of the elbow (especially in the mid-prone position). It originates from the upper two-thirds of the lateral supracondylar ridge of the humerus and inserts into the **base of the styloid process of the radius**. This distal insertion provides a long lever arm, making it a powerful "shunt muscle" that stabilizes the elbow during rapid movements. **2. Analysis of Incorrect Options:** * **Extensor carpi ulnaris (A):** This muscle inserts into the base of the **5th metacarpal bone**, not the radius. * **Supinator (B):** It inserts into the **upper one-third of the lateral surface** of the shaft of the radius, well above the styloid process. * **Anconeus (D):** This small muscle inserts into the lateral aspect of the **olecranon process** and the upper posterior surface of the ulna. **3. NEET-PG High-Yield Pearls:** * **De Quervain’s Tenosynovitis:** The tendons of the Abductor Pollicis Longus (APL) and Extensor Pollicis Brevis (EPB) pass through the first dorsal compartment, located right against the radial styloid. * **Chauffeur’s Fracture:** Also known as a Hutchinson fracture, this is an intra-articular oblique fracture of the **radial styloid process**, often caused by direct compression of the scaphoid against the radius. * **Palpation:** The radial styloid process lies approximately 1 cm more distal than the ulnar styloid process—a key landmark used in the clinical assessment of Colles' fractures.

Question 1

For which of the following nerve palsies is the below test detected?

Accepted Answer

Ulnar nerve

Answer

Median nerve

Answer

Radial nerve

Answer

Anterior interosseous nerve

Question 2

A patient presents with a deep stab wound in the middle of the forearm, resulting in impaired movement of the thumb. Examination suggests a lesion of the anterior interosseous nerve. Which of the following muscles is paralyzed?

Accepted Answer

Flexor digitorum profundus and pronator quadratus

Answer

Flexor pollicis longus and brevis

Answer

Flexor pollicis longus and opponens pollicis

Answer

Flexor digitorum profundus and superficialis

Question 3

Which of the following muscles is spared when the radial nerve is injured in the radial groove?

Accepted Answer

Long head of triceps

Answer

Medial head of triceps

Answer

Lateral head of triceps

Answer

Anconeus

Question 4

Regarding the axilla, which of the following statements is accurate?

Accepted Answer

Pectoralis major and minor contribute to the anterior wall.

Answer

The long thoracic nerve runs on the posterior wall.

Answer

Teres minor forms the lower part of the posterior wall.

Answer

The axillary artery lies anterior to the axillary sheath.

Question 5

Which dermatome corresponds to the middle finger?

Accepted Answer

C7

Answer

C5

Answer

C4

Answer

C2

Question 6

Damage to the C7 nerve root causes weakness of which of the following movements?

Accepted Answer

Wrist flexion

Answer

Elbow flexion

Answer

Supination

Answer

Finger abduction

Question 7

Which of the following movements of the thumb is lost in ulnar nerve injury?

Accepted Answer

Adduction

Answer

Opposition

Answer

Extension

Answer

Abduction

Question 8

The musculocutaneous nerve is a branch of which part of the brachial plexus?

Accepted Answer

Lateral cord

Answer

Root

Answer

Medial cord

Answer

Posterior cord

Question 9

Which maneuver is used to test for integrity of the long thoracic nerve?

Accepted Answer

Raising the arm above the head

Answer

Touching the opposite shoulder

Answer

Shoulder shrug

Answer

Lifting an object from the ground

Question 10

The radial styloid process gives attachment to which of the following muscles?

Accepted Answer

Brachioradialis

Answer

Extensor carpi ulnaris

Answer

Supinator

Answer

Anconeus

Upper Limb — MCQs

Upper Limb — MCQs

On this page

Practice by Chapter

Want unlimited practice?