Two patients from the same village have ulnar nerve injuries. One was cut at the front of the wrist; the other has a lesion behind the medial epicondyle. The resident notes that clawing of the ring and little fingers is more marked in the patient with the wrist injury. What explains this?

Flexor digitorum profundus to these fingers is paralysed in the elbow lesion

The lumbricals are spared in the wrist lesion

Flexor digitorum superficialis is paralysed in the elbow lesion

Extensor digitorum is paralysed in the elbow lesion

Brachial plexus and upper limb nerve injuries

20 NEET-PG practice questions on Brachial plexus and upper limb nerve injuries, part of Anatomy. The first 20 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Easy
A 3.9-kg newborn delivered after shoulder dystocia has an injury of the upper trunk (C5, C6) of the right brachial plexus. The paediatrician examines the right upper limb for four findings: 1. Arm adducted and medially rotated. 2. Absent grasp reflex. 3. Absent biceps reflex. 4. Elbow extended and forearm pronated. Which of these findings are expected?
1. A1, 3 and 4 only
2. B1 and 4 only
3. C1, 2, 3 and 4
4. D1, 2 and 4 only
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Answer: A · 1, 3 and 4 only
Findings 1, 3 and 4 describe Erb palsy, the 'waiter's tip' posture. Loss of the deltoid and supraspinatus (abduction), infraspinatus and teres minor (lateral rotation), and biceps and brachialis (flexion and supination) leaves the arm adducted, medially rotated, extended and pronated, and the biceps reflex (C5, C6) is lost, as is the Moro response on that side. Finding 2 is false: the hand muscles (C8, T1) are spared, so the grasp reflex persists; an absent grasp points to a lower (Klumpke) or total plexus injury. Most infants recover with physiotherapy over months.
- B: Omits the lost biceps reflex, which depends on C5 and C6.
- C: Includes absent grasp; the hand is spared in an upper trunk injury.
- D: Includes absent grasp, which needs C8-T1 injury, and omits the lost biceps reflex.
Question 2 · Medium
A 45-year-old bank clerk has neck pain radiating down the back of the right arm to the middle finger. The right triceps is weak and the triceps jerk is reduced, while the biceps and supinator jerks are normal. MRI shows a disc prolapse. Which nerve root is compressed?
1. AC7
2. BC6
3. CC8
4. DC5
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Answer: A · C7
Weak elbow extension, a reduced triceps jerk and pain or numbness in the middle finger localise to the C7 root, the commonest root involved in cervical radiculopathy. In the cervical spine a root exits above its own vertebra, so a C6-C7 disc usually compresses the C7 root. Biceps and supinator jerks (C5, C6) are normal, which excludes the higher roots. Most patients improve with analgesics and physiotherapy.
- B: C6 compression reduces the biceps and supinator jerks, with numbness of the thumb.
- C: C8 compression weakens the hand muscles, with numbness of the little finger.
- D: C5 compression weakens shoulder abduction and the biceps jerk, with lateral arm numbness.
Question 3 · Medium
Two patients from the same village have ulnar nerve injuries. One was cut at the front of the wrist; the other has a lesion behind the medial epicondyle. The resident notes that clawing of the ring and little fingers is more marked in the patient with the wrist injury. What explains this?
1. AThe lumbricals are spared in the wrist lesion
2. BFlexor digitorum superficialis is paralysed in the elbow lesion
3. CFlexor digitorum profundus to these fingers is paralysed in the elbow lesion
4. DExtensor digitorum is paralysed in the elbow lesion
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Answer: C · Flexor digitorum profundus to these fingers is paralysed in the elbow lesion
Clawing is hyperextension at the metacarpophalangeal joints with flexion at the interphalangeal joints, from loss of the medial lumbricals and interossei while the long flexors and extensors act unopposed. In a lesion at or above the elbow, the ulnar half of flexor digitorum profundus is also paralysed, so the distal phalanges of the ring and little fingers are not pulled into flexion and the claw is milder. This is the 'ulnar paradox': the higher lesion looks less deformed. As the nerve regenerates and FDP recovers first, the claw may paradoxically worsen.
- A: The medial two lumbricals are ulnar-supplied and are lost in both wrist and elbow lesions.
- B: Flexor digitorum superficialis is supplied by the median nerve, not the ulnar nerve.
- D: Extensor digitorum is supplied by the radial (posterior interosseous) nerve, not the ulnar nerve.
Question 4 · Medium
A 22-year-old state-level volleyball player has had a dull ache behind the right shoulder for months. There is visible wasting of the muscles both above and below the spine of the scapula, weakness in starting abduction and in lateral rotation, and no sensory loss. Which nerve is affected?
1. ASuprascapular nerve
2. BDorsal scapular nerve
3. CAxillary nerve
4. DUpper subscapular nerve
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Answer: A · Suprascapular nerve
The suprascapular nerve (C5, C6, from the upper trunk) passes through the suprascapular notch to supply supraspinatus, then round the spinoglenoid notch to supply infraspinatus. Wasting of both fossae, with weakness of the early part of abduction (supraspinatus) and of lateral rotation (infraspinatus), points to it. It has no important skin branch, so there is no sensory loss. Overhead athletes such as volleyball players are prone to this traction or entrapment neuropathy.
- B: The dorsal scapular nerve supplies rhomboids and levator scapulae.
- C: Axillary nerve injury weakens the deltoid and numbs the skin over it.
- D: The upper subscapular nerve supplies subscapularis, a medial rotator.
Question 5 · Medium
A 52-year-old long-distance cyclist from Pune has numbness of the palmar side of the little finger and medial half of the ring finger, with weakness when he tries to spread and close his fingers. Sensation on the dorsum of the medial hand is normal, and flexor digitorum profundus to the little finger is strong. Where is the ulnar nerve most likely compressed?
1. ABehind the medial epicondyle
2. BCubital tunnel at the elbow
3. CProximal third of the forearm
4. DGuyon canal at the wrist
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Answer: D · Guyon canal at the wrist
The dorsal cutaneous branch of the ulnar nerve leaves the trunk several centimetres above the wrist, so a lesion in Guyon canal spares the skin of the dorsal medial hand. Normal profundus power also places the lesion below the forearm branches. Pressure from handlebars on the hypothenar region is a known cause in cyclists. Compression in the elbow region would add numbness of the dorsum and weaken the medial profundus.
- A: Compression behind the medial epicondyle is an elbow lesion with the same added deficits.
- B: A cubital tunnel lesion would also numb the dorsal medial hand and weaken the medial profundus.
- C: A proximal forearm lesion lies above the dorsal cutaneous branch, so the dorsum would be numb.
Question 6 · Hard
A 38-year-old farm worker from Chhattisgarh with borderline leprosy has a thickened, tender nerve palpable behind the left medial epicondyle. The examiner lists four expected findings: 1. Clawing of the ring and little fingers more marked than in a lesion at the wrist. 2. A positive Froment sign. 3. Loss of sensation on the palmar and dorsal surfaces of the medial one and a half fingers. 4. Wasting of the thenar eminence. Which findings are expected?
1. A1, 2 and 3 only
2. B2, 3 and 4 only
3. C2 and 3 only
4. D1 and 2 only
Answer and explanation in LearnFree account
Question 7 · Hard
A 61-year-old bidi smoker from Madhya Pradesh has had left shoulder pain radiating down the inner arm for three months, with weakness and wasting of the small muscles of the left hand. The left eyelid droops, the left pupil is small and the left side of his face does not sweat. Chest X-ray shows an opacity at the left lung apex. Involvement of which structure explains the eye and face findings?
1. ACiliary ganglion
2. BCervicothoracic (stellate) ganglion
3. COculomotor nerve
4. DLower trunk of the brachial plexus
Answer and explanation in LearnFree account
Question 8 · Medium
A 68-year-old woman slips in her bathroom and fractures the surgical neck of the left humerus. Before the fracture is treated, the orthopaedic resident tests sensation over the lower half of the deltoid and finds it reduced. Which other muscle is most likely to be weak?
1. ALatissimus dorsi
2. BTeres minor
3. CTeres major
4. DSupraspinatus
Answer and explanation in LearnFree account
Question 9 · Easy
A 29-year-old woman at 32 weeks of pregnancy complains in the antenatal OPD of tingling and burning in the thumb, index, middle and half of the ring finger of both hands. It wakes her at night and is relieved by shaking her hands. Which nerve is being compressed?
1. ARadial nerve in the forearm
2. BC8 nerve root in the neck
3. CUlnar nerve at the elbow
4. DMedian nerve at the wrist
Answer and explanation in LearnFree account
Question 10 · Hard
A 23-year-old motorcyclist hit the road with his head and right shoulder forced apart. Three weeks later the right arm hangs adducted and medially rotated with the forearm pronated, and the biceps jerk is absent. He also has weakness of the rhomboids and winging of the right scapula on pushing against a wall. Where is the lesion most likely to be?
1. APosterior cord in the axilla
2. BLateral cord in the axilla
3. CUpper trunk at Erb point
4. DC5 and C6 roots
Answer and explanation in LearnFree account
Question 11 · Easy
A 30-year-old construction worker falls from scaffolding and sustains a closed fracture of the middle third of the right humerus. In casualty he cannot extend his wrist or the fingers at the metacarpophalangeal joints, and he has numbness over the dorsum of the first web space. Which nerve is injured?
1. AMedian nerve
2. BUlnar nerve
3. CAxillary nerve
4. DRadial nerve
Answer and explanation in LearnFree account
Question 12 · Medium
A 34-year-old man had a Monteggia fracture-dislocation of the right forearm treated two days ago. He now cannot extend the thumb or the fingers at the metacarpophalangeal joints. He can still extend the wrist, though the hand deviates to the radial side as he does so, and sensation is normal. Which nerve is injured?
1. APosterior interosseous nerve
2. BRadial nerve in the spiral groove
3. CUlnar nerve at the elbow
4. DAnterior interosseous nerve
Answer and explanation in LearnFree account
Question 13 · Medium
A 26-year-old man was stabbed just above the right elbow on the front of the arm. When asked to clasp his hands together, the right index finger stays straight while the other fingers flex; he cannot oppose the thumb and the lateral palm is numb. Where is the nerve lesion?
1. AMedian nerve at the wrist
2. BUlnar nerve above the elbow
3. CMedian nerve above the elbow
4. DAnterior interosseous nerve
Answer and explanation in LearnFree account
Question 14 · Medium
A 47-year-old tailor with carpal tunnel syndrome has numbness of the palmar surface of the lateral three and a half fingers and some wasting of the thenar muscles. Sensation over the skin of the thenar eminence itself is normal. Why is this skin spared?
1. AIts palmar cutaneous branch passes superficial to the flexor retinaculum
2. BThe recurrent branch of the median nerve supplies this skin
3. CIts skin is supplied by the superficial branch of the radial nerve
4. DIts palmar cutaneous branch arises from the ulnar nerve
Answer and explanation in LearnFree account
Question 15 · Medium
A 24-year-old wrestler has a stab wound on the lateral side of the upper arm below the coracoid process. He can still bend his elbow with the forearm in mid-prone position, but elbow flexion with the forearm supinated is weak, the biceps jerk is absent and skin on the lateral forearm is numb. Which nerve is injured?
1. AMusculocutaneous nerve
2. BMedian nerve
3. CRadial nerve
4. DAxillary nerve
Answer and explanation in LearnFree account
Question 16 · Easy
A patient is asked to grip a sheet of paper between the thumb and the side of the index finger while the examiner pulls it away. The thumb flexes strongly at the interphalangeal joint to hold the paper. Weakness of which muscle does this sign reveal?
1. AAbductor pollicis brevis
2. BAdductor pollicis
3. CFlexor pollicis longus
4. DOpponens pollicis
Answer and explanation in LearnFree account
Question 17 · Medium
A 31-year-old software engineer is seen in the orthopaedics OPD with numbness in the hand. The resident wants to confirm carpal tunnel syndrome at the bedside and considers four tests: 1. Tinel sign over the flexor retinaculum. 2. Phalen wrist flexion test. 3. Froment sign. 4. Durkan carpal compression test. Which tests are used for this purpose?
1. ATests 1 and 2 only
2. BTests 1, 2 and 4 only
3. CTests 1, 2, 3 and 4
4. DTests 1, 2 and 3 only
Answer and explanation in LearnFree account
Question 18 · Medium
A newborn delivered by assisted breech in a community health centre had the right arm pulled up above the head to free the after-coming head. On day 2 the paediatrician finds a clawed right hand, an absent grasp reflex on that side and normal movement at the shoulder and elbow. Which roots are most likely injured?
1. AC5 to T1
2. BC7 alone
3. CC5 and C6
4. DC8 and T1
Answer and explanation in LearnFree account
Question 19 · Hard
A 44-year-old man has had numbness of the little finger and ring finger of the right hand for six months. He has weakness of the interossei and of abductor pollicis brevis, and sensory loss over the medial side of the hand and the medial side of the forearm up to the elbow. Nerve conduction studies of the ulnar nerve across the elbow are normal. Where is the lesion most likely to be?
1. AUlnar nerve in the cubital tunnel
2. BLower trunk of the brachial plexus
3. CUlnar nerve in Guyon canal
4. DC6 nerve root
Answer and explanation in LearnFree account
Question 20 · Medium
A 7-year-old boy fell from a mango tree onto his outstretched hand and has a displaced extension-type supracondylar fracture of the humerus. After reduction he cannot make an 'O' with the tip of the thumb and index finger; instead the pulps meet flat. Sensation over the hand is normal. Which nerve is injured?
1. AUlnar nerve
2. BSuperficial branch of radial nerve
3. CAnterior interosseous nerve
4. DPosterior interosseous nerve
Answer and explanation in LearnFree account

Brachial plexus and upper limb nerve injuries

A 45-year-old bank clerk has neck pain radiating down the back of the right arm to the middle finger. The right triceps is weak and the triceps jerk is reduced, while the biceps and supinator jerks are normal. MRI shows a disc prolapse. Which nerve root is compressed?

Two patients from the same village have ulnar nerve injuries. One was cut at the front of the wrist; the other has a lesion behind the medial epicondyle. The resident notes that clawing of the ring and little fingers is more marked in the patient with the wrist injury. What explains this?

A 22-year-old state-level volleyball player has had a dull ache behind the right shoulder for months. There is visible wasting of the muscles both above and below the spine of the scapula, weakness in starting abduction and in lateral rotation, and no sensory loss. Which nerve is affected?

A 68-year-old woman slips in her bathroom and fractures the surgical neck of the left humerus. Before the fracture is treated, the orthopaedic resident tests sensation over the lower half of the deltoid and finds it reduced. Which other muscle is most likely to be weak?

A 29-year-old woman at 32 weeks of pregnancy complains in the antenatal OPD of tingling and burning in the thumb, index, middle and half of the ring finger of both hands. It wakes her at night and is relieved by shaking her hands. Which nerve is being compressed?

A 26-year-old man was stabbed just above the right elbow on the front of the arm. When asked to clasp his hands together, the right index finger stays straight while the other fingers flex; he cannot oppose the thumb and the lateral palm is numb. Where is the nerve lesion?

A 47-year-old tailor with carpal tunnel syndrome has numbness of the palmar surface of the lateral three and a half fingers and some wasting of the thenar muscles. Sensation over the skin of the thenar eminence itself is normal. Why is this skin spared?

A patient is asked to grip a sheet of paper between the thumb and the side of the index finger while the examiner pulls it away. The thumb flexes strongly at the interphalangeal joint to hold the paper. Weakness of which muscle does this sign reveal?