Upper Limb — MCQs

Upper Limb Indian Medical PG Practice Questions and MCQs

Question 411: What is the action of the anterior fibers of the deltoid muscle?

A. Flexion
B. Lateral rotation
C. Flexion and medial rotation (Correct Answer)
D. Extension and lateral rotation

Explanation: The deltoid is a multipennate muscle with three distinct functional sets of fibers. Understanding its action requires looking at the orientation of these fibers relative to the glenohumeral joint axis. **Explanation of the Correct Answer (C):** The **anterior (clavicular) fibers** originate from the lateral third of the clavicle. Because they pass anterior to the center of the humeral head, their contraction pulls the humerus forward and rotates it inward. Therefore, the primary actions of the anterior fibers are **flexion and medial rotation** of the arm at the shoulder. **Analysis of Incorrect Options:** * **A. Flexion:** While correct, it is incomplete. The anterior fibers are also powerful medial rotators. * **B. Lateral rotation:** This is incorrect for the anterior fibers. Lateral rotation is performed by the **posterior fibers** and the infraspinatus/teres minor. * **D. Extension and lateral rotation:** These are the primary actions of the **posterior (spinous) fibers** of the deltoid, which originate from the spine of the scapula and pass behind the joint axis. **NEET-PG High-Yield Pearls:** * **The Multipennate Nature:** The **middle (acromial) fibers** are multipennate, making them the strongest part of the muscle, responsible for **abduction** from 15° to 90°. * **Axillary Nerve (C5, C6):** The deltoid is supplied by the axillary nerve. Damage (e.g., surgical neck fracture or shoulder dislocation) leads to loss of shoulder contour ("square shoulder") and inability to abduct the arm. * **Intramuscular Injections:** Usually given in the middle of the deltoid to avoid the axillary nerve, which winds around the surgical neck of the humerus.

Question 412: Which nerve pierces the coracobrachialis muscle?

A. Axillary nerve
B. Median nerve
C. Musculocutaneous nerve (Correct Answer)
D. Ulnar nerve

Explanation: ### Explanation **Correct Answer: C. Musculocutaneous Nerve** The **musculocutaneous nerve** (C5–C7) is a terminal branch of the **lateral cord** of the brachial plexus. Its hallmark anatomical feature in the arm is that it **pierces the coracobrachialis muscle** to enter the anterior compartment of the arm. After piercing the muscle, it descends between the biceps brachii and the brachialis, supplying all three muscles (Coracobrachialis, Biceps, and Brachialis—mnemonic: **BBC**). It eventually terminates as the lateral cutaneous nerve of the forearm. **Why the other options are incorrect:** * **Axillary nerve (A):** Originates from the posterior cord and exits the axilla through the **quadrangular space** alongside the posterior circumflex humeral artery. It winds around the surgical neck of the humerus. * **Median nerve (B):** Formed by the union of lateral and medial cords. It descends in the arm lateral to the brachial artery, crosses it anteriorly, and enters the cubital fossa without piercing any muscle in the upper arm. * **Ulnar nerve (D):** Originates from the medial cord. It runs medially in the arm and pierces the **medial intermuscular septum** (not a muscle) to enter the posterior compartment before passing behind the medial epicondyle. **High-Yield Clinical Pearls for NEET-PG:** * **Injury Site:** If the musculocutaneous nerve is injured (rare, usually due to heavy trauma or stabs), the patient will have weak forearm flexion and loss of sensation over the lateral aspect of the forearm. * **Reflex:** It is the afferent and efferent limb for the **Biceps Reflex (C5, C6)**. * **Anatomical Variation:** In some individuals, the musculocutaneous nerve may not pierce the coracobrachialis; instead, it may run behind it or communicate with the median nerve.

Question 413: A man presented with a deformity resembling the posture of a waiter waiting to receive a tip. This posture is characteristically seen in which condition?

A. Erb's paralysis (Correct Answer)
B. Klumpke's paralysis
C. Radial nerve paralysis
D. Ulnar nerve paralysis

Explanation: **Explanation:** The "Waiter’s tip" deformity (also known as Policeman’s tip or Porter’s tip hand) is the hallmark clinical presentation of **Erb’s Paralysis**. **1. Why Erb’s Paralysis is correct:** Erb’s paralysis results from an injury to the **Upper Trunk** of the brachial plexus (specifically **C5-C6** roots) at **Erb’s point**. This injury typically occurs due to an increase in the angle between the neck and shoulder (e.g., birth trauma or falling on the shoulder). The paralysis affects the Suprascapular, Axillary, and Musculocutaneous nerves, leading to: * **Arm:** Adducted (loss of abductors) and Medially rotated (loss of lateral rotators). * **Forearm:** Extended (loss of biceps) and Pronated (loss of supinator/biceps). * **Wrist:** Slightly flexed. **2. Why the other options are incorrect:** * **Klumpke’s Paralysis:** Involves the **Lower Trunk (C8-T1)**. It results in a **"Claw Hand"** deformity due to the loss of intrinsic hand muscles, often caused by hyperabduction of the arm. * **Radial Nerve Paralysis:** Characterized by **Wrist Drop** due to the paralysis of the extensors of the wrist and fingers. * **Ulnar Nerve Paralysis:** Leads to a **Partial Claw Hand** (affecting the ring and little fingers) and wasting of the hypothenar eminence. **High-Yield Clinical Pearls for NEET-PG:** * **Erb’s Point:** A junction where 6 nerves meet (C5, C6 roots; Suprascapular, Nerve to Subclavius; Anterior and Posterior divisions of the upper trunk). * **Muscles involved in Erb's:** Primarily Biceps, Brachialis, Deltoid, Supraspinatus, Infraspinatus, and Supinator. * **Moro Reflex:** Characteristically absent on the affected side in neonates with Erb’s palsy.

Question 414: Which of the following is NOT a component of the rotator cuff?

A. Infraspinatus
B. Teres major (Correct Answer)
C. Subscapularis
D. Supraspinatus

Explanation: ### Explanation The **Rotator Cuff** (also known as the musculotendinous cuff) is a functional unit formed by the tendons of four muscles that blend with the fibrous capsule of the shoulder joint. Its primary role is to stabilize the glenohumeral joint by "holding" the head of the humerus in the shallow glenoid cavity. **Why Teres Major is the Correct Answer:** The **Teres major** is often called the "Lat’s little helper" because it shares the same action (adduction and internal rotation) and insertion site (medial lip of the bicipital groove) as the Latissimus dorsi. Crucially, it **does not** attach to the joint capsule or the humeral tubercles (Greater/Lesser), and therefore, it is not part of the rotator cuff. **Analysis of Other Options:** The rotator cuff muscles can be remembered by the mnemonic **SITS**: * **Supraspinatus (D):** Originates from the supraspinous fossa and inserts on the superior impression of the **greater tubercle**. It initiates the first 15° of abduction. * **Infraspinatus (A):** Originates from the infraspinous fossa and inserts on the middle impression of the **greater tubercle**. It acts as a lateral rotator. * **Subscapularis (C):** The only component that inserts on the **lesser tubercle**. It is a powerful medial rotator. * *(Note: Teres minor is the fourth member, inserting on the inferior impression of the greater tubercle).* **High-Yield Clinical Pearls for NEET-PG:** * **Most Common Injury:** The **Supraspinatus** tendon is the most frequently ruptured component of the rotator cuff due to its position under the acromion (subacromial impingement). * **Nerve Supply:** Supraspinatus and Infraspinatus are both supplied by the **Suprascapular nerve** (C5, C6). * **The "Gatekeeper":** The rotator cuff is deficient **inferiorly**, which explains why most shoulder dislocations occur in an antero-inferior direction.

Question 415: A 27-year-old patient presents with an inability to draw the scapula forward and downward because of paralysis of the pectoralis minor. Which of the following would most likely be a cause of his condition?

A. Fracture of the clavicle
B. Injury to the posterior cord of the brachial plexus
C. Fracture of the coracoid process (Correct Answer)
D. Axillary nerve injury

Explanation: Explanation: The **Pectoralis minor** muscle originates from the 3rd, 4th, and 5th ribs and inserts into the **medial border and upper surface of the coracoid process** of the scapula. Its primary actions include pulling the scapula forward (protraction) and downward (depression). A fracture of the coracoid process can lead to an avulsion or functional loss of the pectoralis minor insertion, resulting in the inability to perform these specific movements. **Analysis of Options:** * **Fracture of the coracoid process (Correct):** As the site of insertion for the pectoralis minor, any structural disruption here directly affects the muscle's ability to act on the scapula. * **Fracture of the clavicle:** The pectoralis minor has no attachment to the clavicle. While a clavicular fracture might affect the pectoralis major or subclavius, it would not cause isolated paralysis of the pectoralis minor. * **Injury to the posterior cord:** The pectoralis minor is supplied by the **medial pectoral nerve** (C8, T1), which arises from the **medial cord** of the brachial plexus. The posterior cord gives rise to nerves like the axillary and radial nerves. * **Axillary nerve injury:** This nerve supplies the deltoid and teres minor muscles. Injury would result in loss of shoulder abduction and sensation over the "regimental badge" area, not pectoralis minor dysfunction. **NEET-PG High-Yield Pearls:** * **Coracoid Process Attachments:** Remember the mnemonic **"Short Head of Biceps, Coracobrachialis, and Pectoralis Minor"** (The "Triple C" or "B-C-P" attachments). * **Nerve Supply:** The **Medial Pectoral Nerve** pierces the pectoralis minor to reach the pectoralis major, supplying both. The **Lateral Pectoral Nerve** supplies only the pectoralis major. * **Clinical Significance:** The pectoralis minor serves as a key anatomical landmark, dividing the **axillary artery** into three parts.

Question 416: Which of the following structures do NOT pass deep to the flexor retinaculum?

A. Flexor digitorum superficialis
B. Palmaris longus (Correct Answer)
C. Flexor digitorum profundus
D. Flexor pollicis longus

Explanation: ### Explanation The **flexor retinaculum** (transverse carpal ligament) converts the concave anterior surface of the carpus into the **carpal tunnel** [1]. Understanding which structures pass through this tunnel versus those that remain superficial is a high-yield topic for NEET-PG. **Why Palmaris Longus is the correct answer:** The **Palmaris longus** tendon is a superficial muscle of the forearm. It passes **superficial** (anterior) to the flexor retinaculum and attaches to its distal half and the apex of the palmar aponeurosis. Other structures passing superficial to the retinaculum include the ulnar nerve, ulnar artery, and the palmar cutaneous branches of the median and ulnar nerves [1]. **Analysis of Incorrect Options (Structures passing deep to the retinaculum):** A total of **9 tendons and 1 nerve** pass through the carpal tunnel (deep to the retinaculum): * **Flexor digitorum superficialis (FDS):** Four tendons pass deep to the retinaculum (Option A). * **Flexor digitorum profundus (FDP):** Four tendons pass deep to the retinaculum (Option C). * **Flexor pollicis longus (FPL):** A single tendon passes through its own synovial sheath deep to the retinaculum (Option D). * **Median Nerve:** The most important non-tendinous structure within the tunnel [1]. **Clinical Pearls for NEET-PG:** * **Carpal Tunnel Syndrome:** Compression of the **median nerve** within the tunnel leads to paresthesia in the lateral 3.5 fingers and wasting of thenar muscles [1]. * **Flexor Carpi Radialis (FCR):** This tendon passes through a separate compartment in the lateral attachment of the retinaculum (often considered "within" the retinaculum fibers, but not in the main carpal tunnel). * **Mnemonic for Superficial Structures:** "**P**ulled **U**p **P**almaris" (**P**almar cutaneous nerve, **U**lnar nerve/artery, **P**almaris longus).

Question 417: Which of the following muscles is part of the rotator cuff?

A. Teres major
B. Pectoralis major
C. Pectoralis minor
D. Teres minor (Correct Answer)

Explanation: **Explanation:** The **Rotator Cuff** (also known as the musculotendinous cuff) is a functional unit of four muscles that stabilize the glenohumeral joint by pulling the humeral head into the glenoid cavity. A popular mnemonic to remember these muscles is **SITS**: 1. **S**upraspinatus (Abduction) 2. **I**nfraspinatus (Lateral rotation) 3. **T**eres **minor** (Lateral rotation) 4. **S**ubscapularis (Medial rotation) **Teres minor** is the correct answer as it originates from the lateral border of the scapula and inserts into the greater tubercle of the humerus, forming the posterior-inferior part of the cuff. **Analysis of Incorrect Options:** * **Teres major (A):** Often confused with the minor, it is known as the "Lat's little helper." It inserts into the medial lip of the bicipital groove and does not attach to the joint capsule; hence, it is not part of the rotator cuff. * **Pectoralis major (B) & Pectoralis minor (C):** These are anterior thoracic wall muscles. The Pectoralis major is a powerful adductor and medial rotator, while the Pectoralis minor stabilizes the scapula. Neither contributes to the rotator cuff. **High-Yield Clinical Pearls for NEET-PG:** * **Most commonly injured muscle:** Supraspinatus (especially in impingement syndrome). * **Only muscle inserting on the Lesser Tubercle:** Subscapularis (the other three insert on the Greater Tubercle). * **The "Five" SITS:** Some texts include the long head of the biceps brachii as a functional stabilizer, but anatomically, only the SITS muscles form the cuff. * **Deficient Area:** The rotator cuff is deficient **inferiorly**, making this the most common site for shoulder dislocations.

Question 418: Which of the following statements about the supraspinatus is FALSE?

A. A rotator cuff muscle that does not rotate the humerus.
B. Located deep to the coracoacromial arch.
C. Abducts the arm to the horizontal level. (Correct Answer)
D. The most commonly involved muscle in rotator cuff injuries.

Explanation: **Explanation:** The **supraspinatus** is a critical muscle of the rotator cuff, but its primary role in abduction is limited to the **initial 0–15 degrees**. **Why Option C is FALSE:** While the supraspinatus initiates abduction, the **deltoid** muscle is the primary abductor responsible for taking the arm from 15 degrees up to the horizontal level (90 degrees). Beyond 90 degrees, the serratus anterior and trapezius facilitate upward rotation of the scapula to achieve full overhead abduction. Therefore, stating that the supraspinatus abducts the arm to the horizontal level is anatomically incorrect. **Analysis of Other Options:** * **Option A:** Despite being part of the "rotator" cuff, the supraspinatus is the only member that **does not rotate** the humerus; its vector is purely for initiation of abduction and stabilization of the humeral head. * **Option B:** The muscle belly and tendon lie in the supraspinatus fossa and pass **deep to the coracoacromial arch** (formed by the coracoid process, acromion, and coracoacromial ligament). * **Option D:** Due to its position between the humeral head and the acromion, it is the **most common muscle injured** in rotator cuff tears and impingement syndrome. **High-Yield NEET-PG Pearls:** * **Nerve Supply:** Suprascapular nerve (C5, C6). * **Painful Arc Syndrome:** Pain during abduction between **60°–120°** usually indicates supraspinatus tendinitis or subacromial bursitis. * **Empty Can Test (Jobe’s Test):** Used clinically to assess supraspinatus integrity. * **Blood Supply:** Suprascapular and posterior circumflex humeral arteries.

Question 419: The cords of the brachial plexus are named relative to the axillary artery. Which muscle lies behind the axillary artery in relation to these cords?

A. Deltoid
B. Subclavius
C. Teres major
D. Pectoralis minor (Correct Answer)

Explanation: The **Pectoralis minor** muscle is the key anatomical landmark used to divide the axillary artery into three parts [1]. More importantly, it defines the position and naming of the **cords of the brachial plexus**: 1. **First part** (proximal to muscle): Cords are not yet formed (divisions are present). 2. **Second part** (behind the muscle): The cords are named **Lateral, Medial, and Posterior** based on their specific orientation to the axillary artery at this exact location [1]. 3. **Third part** (distal to muscle): The cords begin to branch into terminal nerves. Therefore, the Pectoralis minor is the muscle that physically overlies the second part of the axillary artery and the surrounding cords [1]. **Analysis of Incorrect Options:** * **Deltoid (A):** A superficial muscle of the shoulder; it does not serve as a landmark for the divisions of the axillary artery or the cords. * **Subclavius (B):** Located superiorly, it protects the neurovascular bundle as it passes under the clavicle but does not define the relationship of the cords to the artery. * **Teres major (C):** Marks the **inferior boundary** where the axillary artery becomes the brachial artery. It lies distal to the cords. **High-Yield NEET-PG Pearls:** * **The "Rule of 3s":** Pectoralis minor divides the axillary artery into **3 parts**; the 1st part has **1 branch**, the 2nd part has **2 branches**, and the 3rd part has **3 branches**. * **Clavipectoral Fascia:** Pierced by four structures: Lateral pectoral nerve, Thoraco-acromial artery, Cephalic vein, and Lymphatics. * **Safe Zone:** For axillary nerve blocks, the relationship of the cords to the artery behind the Pectoralis minor is crucial for successful anesthesia.

Question 420: The anterior interosseous nerve is a branch of which of the following?

A. Superficial branch of the radial nerve
B. Deep branch of the radial nerve
C. Median nerve (Correct Answer)
D. Ulnar nerve

Explanation: ### Explanation **Correct Answer: C. Median nerve** The **Anterior Interosseous Nerve (AIN)** is the largest branch of the **median nerve** in the forearm. It arises in the cubital fossa between the two heads of the pronator teres [1]. It descends on the anterior surface of the interosseous membrane alongside the anterior interosseous artery [1]. **Why it is correct:** The AIN is a purely motor nerve (with sensory fibers only for joint capsules). It supplies the **"Deep Group"** of muscles in the anterior compartment of the forearm: 1. **Flexor pollicis longus (FPL)** 2. **Pronator quadratus (PQ)** 3. **Lateral half of Flexor digitorum profundus (FDP)** (supplying the index and middle fingers). **Why incorrect options are wrong:** * **Options A & B (Radial Nerve):** The radial nerve and its deep branch (Posterior Interosseous Nerve) supply the **posterior (extensor)** compartment of the forearm. * **Option D (Ulnar Nerve):** The ulnar nerve supplies the Flexor Carpi Ulnaris and the medial half of the FDP [1]. It does not give off the AIN. --- ### High-Yield Clinical Pearls for NEET-PG * **AIN Syndrome (Kiloh-Nevin Syndrome):** This is an isolated palsy of the AIN (often due to compression). * **The "OK Sign" Test:** Patients with AIN palsy cannot flex the distal phalanges of the thumb and index finger. When asked to make an "OK" sign, they produce a **"pinch"** (flat finger-to-finger contact) instead of a circle, due to paralysis of the FPL and the lateral half of the FDP. * **Sensory Note:** Unlike the main median nerve, the AIN has **no cutaneous distribution**. It only provides sensory innervation to the wrist and distal radio-ulnar joints.

Practice by Chapter

Pectoral Region and Axilla

Practice Questions

Arm and Cubital Fossa

Practice Questions

Forearm and Hand

Practice Questions

Joints of Upper Limb

Practice Questions

Nerves of Upper Limb

Practice Questions

Arterial Supply and Venous Drainage

Practice Questions

Lymphatic Drainage

Practice Questions

Muscles and Their Actions

Practice Questions

Applied Anatomy and Clinical Correlations

Practice Questions

Surface Anatomy and Landmarks

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free

Upper Limb — MCQs

Upper Limb — MCQs

On this page

Practice by Chapter

Want unlimited practice?