Upper Limb Practice Questions

Q: A patient came with inability to move his 4th and 5th digit and cannot hold pen or paper between his fingers. Which of the following sites shown below is the probable cause of nerve injury to this patient?

C. **C** - The symptoms described (inability to move the 4th and 5th digits and difficulty with adduction/abduction of fingers, e.g., holding a pen) are characteristic of **ulnar nerve injury**. - The ulnar nerve passes behind the **medial epicondyle** of the humerus, which corresponds to location **C** in the image, making it vulnerable to injury here. *A* - Location **A** represents the surgical neck of the humerus. Injury here primarily affects the **axillary nerve**, leading to weakness in shoulder abduction and loss of sensation over the deltoid. - This does not explain the specific loss of function in the 4th and 5th digits. *B* - Location **B** represents the mid-shaft of the humerus. Fractures here commonly injure the **radial nerve**, leading to "wrist drop" and sensory loss over the posterior forearm and hand. - This injury pattern does not match the patient's symptoms affecting the ulnar side of the hand. *D* - Location **D** represents the lateral epicondyle of the humerus. This area is associated with conditions like **tennis elbow** (lateral epicondylitis), which involves inflammation of the common extensor origin. - Nerve injuries related to this area typically involve the deep branch of the **radial nerve** (posterior interosseous nerve), leading to weakness in finger and thumb extension, not ulnar nerve symptoms.

Q: Which of the following bones is the first one to ossify?

C. ***C*** - The **capitate bone** is the first carpal bone to ossify, typically appearing around **1-3 months** of postnatal life. - As the largest carpal bone, its early ossification serves as an important radiological marker for assessing **skeletal maturity** in pediatric patients. *A* - The **scaphoid bone** ossifies much later, around **5-6 years** of age, making it one of the last carpal bones to develop. - Due to its **retrograde blood supply**, the scaphoid is particularly susceptible to **avascular necrosis** following fractures. *B* - The **trapezoid bone** typically begins ossification between **4-6 years** of age, significantly later than the capitate. - Located between the **trapezium and capitate**, it forms part of the distal carpal row and contributes to **index finger stability**. *D* - The **lunate bone** usually starts ossifying around **2-4 years** of age, making it the second carpal bone to ossify after the capitate. - The lunate is clinically significant as it's commonly affected by **Kienböck's disease** (avascular necrosis) and **perilunate dislocations**.

Q: The image displays a hand with a distinct palmar crease pattern where a transverse crease extends from the radial to the ulnar border, in addition to another proximal transverse crease. What is this specific crease pattern called?

Sydney line. ***Sydney line*** - The image illustrates a hand with a distinct palmar crease pattern where a **transverse crease extends from the radial to the ulnar border**, in addition to another proximal transverse crease. - This specific crease pattern, where the proximal transverse crease reaches the ulnar border of the hand, is known as a **Sydney line** and is often associated with certain chromosomal abnormalities like Down syndrome, though it can also occur in healthy individuals. *Simian crease* - A **simian crease**, also known as a single transverse palmar crease, involves only **one prominent crease spanning across the entire palm**, often replacing the usual two transverse creases. - The image shows a hand with **two distinct transverse creases**, one extending completely across and another shorter one, meaning it is not a simian crease. *Sandal gap* - A **sandal gap** refers to a **wide gap between the first and second toes**, which is a feature of the foot, not the hand. - This term is therefore **irrelevant** to the crease pattern observed on a hand. *Kennedy crease* - The term **Kennedy crease** is **not a recognized medical or anatomical term** for a palmar crease pattern. - This option is a **distractor** and does not describe any known crease variation.

Q: The inability to flex the index finger is a sign of

Median nerve injury. ***Median nerve injury*** - The **median nerve** innervates the **flexor digitorum superficialis** and the **flexor digitorum profundus** (radial half), which are responsible for flexing the index and middle fingers. [1] - Damage to this nerve at a high level (e.g., above the elbow) would impact these muscles, leading to an **inability to flex the index finger**. [1] *Radial nerve injury* - The **radial nerve** primarily innervates the **extensor muscles** of the arm and forearm. - Injury to this nerve would result in difficulty extending the wrist and fingers (e.g., **wrist drop**), not flexing them. *Ulnar nerve injury* - The **ulnar nerve** innervates the **flexor carpi ulnaris** and the **ulnar half of the flexor digitorum profundus** (ring and pinky finger). [1] - Damage would primarily affect the flexion of the ring and little fingers, as well as intrinsic hand muscles, leading to a **claw hand deformity**. *Dupuytren's contracture* - This condition involves **fibrosis and thickening of the palmar fascia**, causing the fingers (most commonly the ring and little fingers) to permanently flex towards the palm. - It is a **fibroproliferative disorder** of the hand, not a nerve injury, and typically affects flexibility in multiple fingers in a characteristic pattern, rather than a specific inability to flex one finger due to paralysis.

Q: A patient presents with loss of sensation on the lateral 3½ fingers and thenar atrophy. Which nerve is most likely involved?

Median. ***Median*** - The **median nerve** provides sensation to the **lateral 3½ fingers** (thumb, index, middle, and radial half of the ring finger) and innervates the **thenar muscles**, making its involvement consistent with the described symptoms [1]. - **Thenar atrophy** points directly to motor innervation loss of the thenar eminence, which is a key function of the median nerve. *Ulnar* - The **ulnar nerve** supplies sensation to the **medial 1½ fingers** (little finger and ulnar half of the ring finger) and innervates most of the **intrinsic hand muscles**, but not the thenar muscles [1]. - Damage typically causes **hypothenar atrophy** and **clawing** of the 4th and 5th digits, which are not described here. *Radial* - The **radial nerve** primarily provides sensation to the **dorsal aspect of the hand** and innervates the **extensor muscles of the forearm and hand**. - Its injury would typically lead to **wrist drop** and sensory loss in the dorsal hand, not thenar atrophy or lateral finger sensory loss. *Anterior interosseous nerve* - The **anterior interosseous nerve** is a **purely motor branch of the median nerve** that innervates muscles involved in **flexion of the thumb IP joint** and **index finger DIP joint**. - It does not have any sensory innervation, so loss of sensation in the lateral 3½ fingers would not be a symptom.

Q: Froment's sign (book test) is used to assess the function of adductor pollicis. Which of the following nerves supplies this muscle?

Ulnar nerve. The adductor pollicis muscle is primarily innervated by the deep branch of the ulnar nerve [1]. This muscle is crucial for thumb adduction, and its function is assessed by the Froment's sign (often referred to as the book test) to detect ulnar nerve palsy. The radial nerve primarily innervates the muscles of the posterior compartment of the arm and forearm, responsible for wrist and finger extension [1]. It does not supply any intrinsic muscles of the hand, including the adductor pollicis [1]. The posterior interosseous nerve is a terminal branch of the deep radial nerve, supplying most of the extensors in the forearm [1]. It does not innervate any of the intrinsic hand muscles. The median nerve innervates most of the flexors of the forearm and the thenar muscles of the hand (abductor pollicis brevis, opponens pollicis, and superficial head of flexor pollicis brevis) [1]. It does not supply the adductor pollicis muscle; median nerve palsy would affect thumb opposition and abduction, not adduction [1].

Q: What is the action of the muscle shown in the image below?

Retracts the scapula. ***Retracts the scapula*** - The image highlights the **rhomboid major** muscle, which originates from the spinous processes of T2-T5 vertebrae and inserts onto the medial border of the scapula. - Its primary action is to **retract** (pull medially) and rotate the scapula inferiorly, and also to help hold the scapula against the thoracic wall. *Medial rotation of the shoulder* - Medial rotation of the shoulder is primarily performed by muscles like the **subscapularis**, **pectoralis major**, **latissimus dorsi**, and **teres major**. - The rhomboids do not directly act on the glenohumeral joint for shoulder rotation. *Adduction of the shoulder* - Adduction of the shoulder (bringing the arm towards the body) is mainly performed by the **latissimus dorsi**, **pectoralis major**, and **teres major**. - The rhomboids' action on the scapula indirectly influences shoulder movement but does not directly adduct the shoulder joint. *Extension of the shoulder* - Shoulder extension is primarily achieved by the **latissimus dorsi**, **teres major**, and the posterior fibers of the **deltoid**. - The rhomboid major muscle's action focuses solely on the scapula, not direct extension of the shoulder joint.

Q: A patient who has taken the first COVID vaccine comes for the second dose. An astute nurse noticed that the shoulder was flabby, flat, and was asymmetrical. There was an associated loss of contour of the shoulder joint. Injury to which of the structures might have resulted and was avoidable?

Deltoid muscle. ***Deltoid muscle*** - The **deltoid muscle** is the principal muscle that gives the shoulder its rounded contour. Damage to or atrophy of the deltoid can lead to a **flat, flabby, and asymmetrical shoulder**. - Improper vaccine administration, such as injecting too high or too deep, can directly injure the deltoid muscle, leading to inflammation (**SIRVA - Shoulder Injury Related to Vaccine Administration**) or even deltoid atrophy, which would cause the observed lack of contour. *Supraspinatus muscle* - The **supraspinatus** is primarily involved in the initial **abduction** of the arm and stabilization of the shoulder joint, but it does not significantly contribute to the visible external contour of the shoulder. - Injury to the supraspinatus mainly causes **pain and weakness** with abduction, rather than a visible change in shoulder shape. *Infraspinatus muscle* - The **infraspinatus** is a rotator cuff muscle primarily responsible for **external rotation** of the arm. - Injury to this muscle would cause weakness in external rotation and potentially posterior shoulder pain, but not the noticeable loss of shoulder contour described. *Teres minor muscle* - The **teres minor** is also a rotator cuff muscle assisting in **external rotation** and stabilization of the humeral head. - Similar to the infraspinatus, its injury would impair external rotation and cause posterior shoulder pain, but it doesn't define the overall shape of the shoulder.

Q: A patient presents with difficulty extending their wrist following trauma to the posterior forearm. Which of the following muscles would be most affected by injury to the posterior interosseous nerve?

Extensor digitorum. ***Extensor digitorum*** - The **posterior interosseous nerve (PIN)** innervates most muscles of the **posterior compartment of the forearm**, including the extensor digitorum. [1] - Loss of function in the **extensor digitorum** would directly impair **extension of the fingers** and contribute significantly to difficulty extending the wrist. [1] *Extensor carpi ulnaris* - This muscle is also innervated by the **posterior interosseous nerve (PIN)** and contributes to **wrist extension** and **ulnar deviation**. - While its innervation by the PIN is correct, injury to the PIN would affect this muscle, but the *extensor digitorum* is more broadly responsible for the stated primary symptom (difficulty extending the wrist), as its primary action is finger and thus wrist extension. *Extensor carpi radialis brevis* - While it is a **wrist extensor**, it is innervated by the **deep branch of the radial nerve** *before* it becomes the posterior interosseous nerve. - Therefore, an isolated injury to the **posterior interosseous nerve** proper would typically spare the extensor carpi radialis brevis. *Extensor pollicis longus* - This muscle is indeed innervated by the **posterior interosseous nerve (PIN)** and acts to extend the **thumb**. [1] - While it would be affected, the primary problem described is difficulty extending the *wrist*, for which the extensor digitorum plays a more significant and general role than the extensor pollicis longus.

Question 1

A patient came with inability to move his 4th and 5th digit and cannot hold pen or paper between his fingers. Which of the following sites shown below is the probable cause of nerve injury to this patient?

Accepted Answer

C

Answer

A

Answer

B

Answer

D

Question 2

Which of the following bones is the first one to ossify?

Accepted Answer

C

Answer

A

Answer

B

Answer

D

Question 3

The image displays a hand with a distinct palmar crease pattern where a transverse crease extends from the radial to the ulnar border, in addition to another proximal transverse crease. What is this specific crease pattern called?

Accepted Answer

Sydney line

Answer

Simian crease

Answer

Sandal gap

Answer

Kennedy crease

Question 4

Lesion at \qquad level leads to deformity shown in neonate born after prolonged labor?

Accepted Answer

C5-C8

Answer

C1-C3

Answer

C3-C5

Answer

C8-T1

Question 5

The inability to flex the index finger is a sign of

Accepted Answer

Median nerve injury

Answer

Radial nerve injury

Answer

Ulnar nerve injury

Answer

Dupuytren's contracture

Question 6

A patient presents with loss of sensation on the lateral 3½ fingers and thenar atrophy. Which nerve is most likely involved?

Accepted Answer

Median

Answer

Ulnar

Answer

Radial

Answer

Anterior interosseous nerve

Question 7

Froment's sign (book test) is used to assess the function of adductor pollicis. Which of the following nerves supplies this muscle?

Accepted Answer

Ulnar nerve

Answer

Radial nerve

Answer

Posterior interosseous nerve

Answer

Median nerve

Question 8

What is the action of the muscle shown in the image below?

Accepted Answer

Retracts the scapula

Answer

Medial rotation of the shoulder

Answer

Adduction of the shoulder

Answer

Extension of the shoulder

Question 9

A patient who has taken the first COVID vaccine comes for the second dose. An astute nurse noticed that the shoulder was flabby, flat, and was asymmetrical. There was an associated loss of contour of the shoulder joint. Injury to which of the structures might have resulted and was avoidable?

Accepted Answer

Deltoid muscle

Answer

Supraspinatus muscle

Answer

Infraspinatus muscle

Answer

Teres minor muscle

Question 10

A patient presents with difficulty extending their wrist following trauma to the posterior forearm. Which of the following muscles would be most affected by injury to the posterior interosseous nerve?

Accepted Answer

Extensor digitorum

Answer

Extensor carpi ulnaris

Answer

Extensor carpi radialis brevis

Answer

Extensor pollicis longus

Upper Limb — MCQs

Upper Limb — MCQs

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