Upper Limb Practice Questions

Q: Which of the following is NOT typically seen in carpal tunnel syndrome?

Ulnar nerve involvement. **Explanation:** **Carpal Tunnel Syndrome (CTS)** is the most common entrapment neuropathy, caused by the compression of the **median nerve** as it passes through the carpal tunnel beneath the flexor retinaculum [2]. **1. Why Ulnar Nerve Involvement is the Correct Answer:** The ulnar nerve does **not** pass through the carpal tunnel. Instead, it travels superficial to the flexor retinaculum through **Guyon’s canal** (ulnar canal) [2]. Therefore, compression within the carpal tunnel typically spares the ulnar nerve. Clinical symptoms of CTS are localized to the median nerve distribution (lateral 3.5 fingers) [2]. **2. Analysis of Incorrect Options:** * **Median Nerve Compression (A):** This is the hallmark of CTS. The nerve is squeezed against the rigid walls of the tunnel, leading to paresthesia and thenar atrophy [1]. * **FPL (C) and FDP (D) Tendon Issues:** The carpal tunnel contains **10 structures**: the median nerve, the tendon of Flexor Pollicis Longus (1), the four tendons of Flexor Digitorum Superficialis (4), and the four tendons of Flexor Digitorum Profundus (4) [1]. Inflammation or tenosynovitis of these tendons is a primary cause of increased pressure within the tunnel, leading to nerve compression. **High-Yield Clinical Pearls for NEET-PG:** * **Sensory Sparing:** The **palmar cutaneous branch** of the median nerve arises proximal to the carpal tunnel; thus, sensation over the lateral palm is usually **preserved** in CTS [1], [2]. * **Tests:** Phalen’s test (forced flexion) and Tinel’s sign (percussion over the nerve) are classic diagnostic maneuvers. * **Muscle Involvement:** "LOAF" muscles (Lateral two lumbricals, Opponens pollicis, Abductor pollicis brevis, Flexor pollicis brevis) are affected. * **Most Common Cause:** Idiopathic; however, it is associated with pregnancy, hypothyroidism, diabetes, and rheumatoid arthritis.

Q: Which statement regarding the anatomical spaces of the hand is true?

The thenar space lies lateral to the 3rd metacarpal.. **Explanation:** The deep fascial spaces of the palm are potential spaces filled with loose connective tissue, clinically significant for the localization and spread of infections [1]. **1. Why Option A is Correct:** The **thenar space** is a triangular space located deep to the thenar muscles. Its medial boundary is the **lateral palmar septum**, which is attached to the **3rd metacarpal bone**. Therefore, the thenar space lies lateral to the 3rd metacarpal, between it and the thenar eminence [1]. **2. Analysis of Incorrect Options:** * **Option B:** The **hypothenar space** is contained within the hypothenar compartment, bounded by the medial palmar septum (attached to the 5th metacarpal). It does not lie medial to the bone but rather surrounds the hypothenar muscles anterior/lateral to it. * **Option C:** While the **midpalmar space** is deep to the palmar aponeurosis, this is a vague description. Specifically, it lies deep to the **flexor tendons** and superficial to the interossei/metacarpals [1]. Option A is the more anatomically precise "textbook" definition regarding boundaries. * **Option D:** The **pulp spaces** (Whitman’s spaces) are located on the palmar aspect of the **distal phalanges** only, not the entire length of the fingers and thumb. They are partitioned by fibrous septa extending from the skin to the periosteum. **3. NEET-PG High-Yield Pearls:** * **Kanavel’s Signs:** Used to diagnose infectious tenosynovitis (e.g., symmetric swelling, finger in slight flexion, tenderness over sheath, pain on passive extension). * **Space of Parona:** A potential space in the distal forearm (deep to flexor tendons, superficial to pronator quadratus) where infections from the radial or ulnar bursae can track. * **Communication:** The midpalmar space often communicates with the forearm via the carpal tunnel.

Q: Which structure is referred to as a "dynamic stabilizer" of the shoulder joint?

Rotator cuff. **Explanation:** The shoulder (glenohumeral) joint is characterized by a high degree of mobility at the expense of stability, often compared to a "ball on a saucer." To maintain integrity, it relies on both static and dynamic stabilizers. **1. Why Rotator Cuff is Correct:** The **Rotator Cuff muscles** (Supraspinatus, Infraspinatus, Teres minor, and Subscapularis—mnemonic: **SITS**) are the primary **dynamic stabilizers**. They function by actively contracting to compress the humeral head into the shallow glenoid cavity throughout the range of motion. This mechanism, known as **"concavity-compression,"** prevents the humeral head from sliding out of the socket during movement. **2. Why Other Options are Incorrect:** * **Glenoid Labrum (B):** This is a fibrocartilaginous rim that deepens the glenoid cavity. It is a **static stabilizer**. * **Coracohumeral (C) and Glenohumeral Ligaments (D):** These are thickened parts of the joint capsule that provide stability only at the end-ranges of motion or when the muscles are relaxed. They are classified as **static stabilizers**. **3. NEET-PG High-Yield Pearls:** * **The "Fifth" Dynamic Stabilizer:** The **Long head of the Biceps brachii** is also considered a dynamic stabilizer as it prevents upward displacement of the humeral head. * **Weakest Point:** The rotator cuff is deficient **inferiorly**, which is why most shoulder dislocations occur in an antero-inferior direction. * **Rotator Interval:** A triangular space between the Supraspinatus and Subscapularis tendons; it is a common site for clinical pathology and surgical entry. * **Supraspinatus:** The most commonly injured rotator cuff muscle (often involved in impingement syndrome).

Q: Which of the following is NOT a ligament of the shoulder joint?

Coracoclavicular. The shoulder joint (glenohumeral joint) is a ball-and-socket synovial joint characterized by a wide range of motion but inherent instability. Its stability is maintained by a series of intrinsic and extrinsic ligaments. **Why Coracoclavicular is the Correct Answer:** The **Coracoclavicular ligament** is not a ligament of the shoulder joint; rather, it is the primary stabilizer of the **Acromioclavicular (AC) joint**. It connects the coracoid process of the scapula to the undersurface of the clavicle and consists of two parts: the **conoid** and **trapezoid** ligaments. While it helps suspend the weight of the upper limb from the clavicle, it does not involve the humerus or the glenohumeral articulation. **Analysis of Incorrect Options:** * **Glenohumeral ligaments:** These are three thickenings (superior, middle, and inferior) of the anterior joint capsule that strengthen the shoulder joint. * **Coracohumeral ligament:** A strong band extending from the root of the coracoid process to the greater tubercle of the humerus, strengthening the upper part of the capsule. * **Transverse humeral ligament:** A small band bridging the gap between the greater and lesser tubercles, converting the bicipital groove into a canal for the long head of the biceps tendon. **High-Yield Clinical Pearls for NEET-PG:** * **Stability:** The shoulder joint is the most frequently dislocated joint in the body. * **Rotator Cuff (SITS):** The "dynamic stabilizers" of the shoulder are the Supraspinatus, Infraspinatus, Teres minor, and Subscapularis. * **Glenoid Labrum:** A fibrocartilaginous rim that deepens the glenoid cavity to increase stability. * **AC Joint Dislocation:** Often involves tearing of the coracoclavicular ligament, leading to the "step-off" deformity of the shoulder.

Q: Injury to the median nerve occurs frequently when which artery is used for taking an ABG sample?

Brachial artery. ### Explanation **1. Why the Brachial Artery is Correct:** The **median nerve** and the **brachial artery** share a very close anatomical relationship in the cubital fossa. At the level of the elbow, the median nerve lies immediately **medial** to the brachial artery. Both structures are protected only by the thin bicipital aponeurosis. During an Arterial Blood Gas (ABG) sampling or a brachial artery puncture, a needle that deviates medially or is inserted too deeply can easily transfix or compress the median nerve, leading to sensory loss in the lateral 3.5 fingers and motor deficits in the forearm and hand. **2. Analysis of Incorrect Options:** * **A. Radial Artery:** This is the most common site for ABG sampling. While the superficial branch of the radial nerve is nearby, the median nerve is distant from the radial artery at the wrist. * **C. External Carotid Artery:** This artery is located in the neck. It is not used for routine ABG sampling, and its injury would involve cranial nerves (like the hypoglossal or vagus), not the median nerve. * **D. Femoral Artery:** Located in the femoral triangle in the groin. The nerve in close proximity here is the **femoral nerve** (lateral to the artery), not the median nerve. **3. NEET-PG High-Yield Pearls:** * **Cubital Fossa Contents (Medial to Lateral):** **M**edian Nerve, **B**rachial Artery, **B**iceps Tendon, **R**adial Nerve (Mnemonic: **MBBR**). * **Supracondylar Fracture of Humerus:** This is the most common traumatic cause of concurrent injury to the brachial artery and median nerve. * **Pronator Teres Syndrome:** Another site of median nerve entrapment, occurring as the nerve passes between the two heads of the pronator teres muscle. * **Allen’s Test:** Always performed before radial artery puncture to ensure collateral circulation via the ulnar artery.

Q: Which of the following arteries is most likely at risk during venipuncture at the cubital fossa?

Brachial. **Explanation:** The **cubital fossa** is a common site for venipuncture, specifically targeting the **median cubital vein**. The correct answer is the **brachial artery** because of its critical anatomical relationship to this vein. 1. **Why Brachial Artery is Correct:** The brachial artery lies immediately deep to the median cubital vein. It is separated from the vein only by the **bicipital aponeurosis** (a thin, fibrous sheet). During venipuncture, if the needle passes too deeply or pierces the aponeurosis, it can inadvertently puncture the brachial artery, leading to hematoma or intra-arterial injection. 2. **Why Incorrect Options are Wrong:** * **Common Interosseous Artery:** This is a short branch of the ulnar artery that arises distal to the cubital fossa, deep in the forearm. * **Ulnar Artery:** While it originates in the cubital fossa as a terminal branch of the brachial artery, it quickly passes deep to the pronator teres muscle, moving away from the superficial venous access site. * **Anterior Interosseous Artery:** This is a branch of the common interosseous artery located deep on the interosseous membrane, far from the superficial cubital skin. **Clinical Pearls for NEET-PG:** * **Mnemonic for Cubital Fossa Contents (Medial to Lateral):** **MBBR** — **M**edian nerve, **B**rachial artery, **B**iceps tendon, **R**adial nerve. * **Bicipital Aponeurosis:** Also known as the "grace d'ieu" fascia, it serves as a protective barrier for the brachial artery and median nerve during venipuncture. * **Median Nerve:** Along with the brachial artery, the median nerve is also at risk of injury during deep needle insertion in the medial aspect of the fossa.

Q: In radial nerve injuries, paralysis of the brachioradialis, extensor carpi radialis longus and brevis, extensor digitorum, and extensor pollicis longus, but sparing of the triceps, places the nerve lesion at which level?

The level of the humeral shaft (mid). ### Explanation The radial nerve originates from the posterior cord of the brachial plexus (C5-T1). To determine the level of a radial nerve lesion, one must evaluate the sequence of motor branches. **1. Why the Correct Answer is Right:** The **triceps brachii** is supplied by the radial nerve in the axilla and the upper part of the spiral groove. If the triceps is **spared**, the lesion must be distal to these branches. The branches to the **brachioradialis (BR)** and **extensor carpi radialis longus (ECRL)** arise just above the elbow (lateral supracondylar ridge). Since these muscles are paralyzed along with the finger and thumb extensors, the lesion must be located between the origin of the triceps branches and the elbow—specifically, at the **humeral shaft (mid-shaft)** within the spiral groove. **2. Why the Incorrect Options are Wrong:** * **Level of the elbow (A):** A lesion here (e.g., Posterior Interosseous Nerve palsy) would spare the BR and ECRL, as their innervation occurs proximal to the elbow. * **Avulsion at nerve root (C) / Brachial plexus (D):** Lesions at these proximal levels would involve the triceps, resulting in the loss of elbow extension, and would likely present with additional deficits in other nerves (e.g., axillary or ulnar). **3. Clinical Pearls for NEET-PG:** * **Saturday Night Palsy:** Compression in the axilla; triceps is involved. * **Holstein-Lewis Fracture:** Spiral fracture of the distal third of the humerus; most commonly associated with radial nerve palsy. * **Wrist Drop:** The hallmark of radial nerve injury above the level of the wrist. * **PIN Palsy (Low Radial Nerve Palsy):** Characterized by "Finger Drop" with **no** wrist drop (because ECRL is spared) and no sensory loss.

Question 1

Which of the following is NOT typically seen in carpal tunnel syndrome?

Accepted Answer

Ulnar nerve involvement

Answer

Median nerve compression

Answer

Flexor pollicis longus (FPL) tendon issues

Answer

Flexor digitorum profundus (FDP) tendon issues

Question 2

Which statement regarding the anatomical spaces of the hand is true?

Accepted Answer

The thenar space lies lateral to the 3rd metacarpal.

Answer

The hypothenar space lies medial to the 5th metacarpal.

Answer

The midpalmar space lies deep to the palmar aponeurosis.

Answer

The pulp spaces lie on the palmar aspect of the fingers and thumb.

Question 3

A 22-year-old man presents to the emergency department after sustaining trauma. He reports severe pain radiating across his back and down his left upper limb. He is supporting his left upper limb with his right, holding it close to his body, and any attempt to move the limb exacerbates the pain. A radiograph reveals a sagittal fracture through the spine of the left scapula that extends superiorly toward the suprascapular notch. Which nerve is most likely affected?

Accepted Answer

Suprascapular nerve

Answer

Thoracodorsal nerve

Answer

Axillary nerve

Answer

Subscapular nerve

Question 4

A patient presented with inability to flex the distal interphalangeal joints of the fourth and fifth fingers and is unable to hold a card between his fingers. Fracture at which of the following sites might have damaged the nerve, leading to this set of clinical features?

Accepted Answer

Hamate fracture

Answer

Scaphoid fracture

Answer

Colles' fracture

Answer

Bennett's fracture

Question 5

Which structure is referred to as a "dynamic stabilizer" of the shoulder joint?

Accepted Answer

Rotator cuff

Answer

Glenoid labrum

Answer

Coracohumeral ligament

Answer

Glenohumeral ligament

Question 6

Which of the following statements regarding the brachial plexus is true?

Accepted Answer

The radial nerve arises from the posterior cord.

Answer

A cervical rib typically involves the lateral cord.

Answer

The musculocutaneous nerve originates from the medial cord.

Answer

A post-fixed brachial plexus is formed by C4, C5, C6, C7, C8, and T1.

Question 7

Which of the following is NOT a ligament of the shoulder joint?

Accepted Answer

Coracoclavicular

Answer

Glenohumoral

Answer

Coracohumeral

Answer

Transverse humeral

Question 8

Injury to the median nerve occurs frequently when which artery is used for taking an ABG sample?

Accepted Answer

Brachial artery

Answer

Radial artery

Answer

External carotid artery

Answer

Femoral artery

Question 9

Which of the following arteries is most likely at risk during venipuncture at the cubital fossa?

Accepted Answer

Brachial

Answer

Common interosseous

Answer

Ulnar

Answer

Anterior interosseous

Question 10

In radial nerve injuries, paralysis of the brachioradialis, extensor carpi radialis longus and brevis, extensor digitorum, and extensor pollicis longus, but sparing of the triceps, places the nerve lesion at which level?

Accepted Answer

The level of the humeral shaft (mid)

Answer

The level of the elbow

Answer

Avulsion at the nerve root level

Answer

The level of the brachial plexus

Upper Limb — MCQs

Upper Limb — MCQs

On this page

Practice by Chapter

Want unlimited practice?