Seven hours after undergoing left hip arthroplasty for chronic hip pain, a 67-year-old woman reports a prickling sensation in her left anteromedial thigh and lower leg. Neurologic examination shows left leg strength 3/5 on hip flexion and 2/5 on knee extension. Patellar reflex is decreased on the left. Sensation to pinprick and light touch are decreased on the anteromedial left thigh as well as medial lower leg. Which of the following is the most likely underlying cause of this patient's symptoms?
Q82
A 25-year-old man presents to the emergency department after a car accident. He was the front seat restrained driver in a head-on collision. He has no significant past medical history. The patient’s vitals are stabilized and he is ultimately discharged with his injuries appropriately treated. At the patient’s follow up primary care appointment, he complains of being unable to lift his left foot. He otherwise states that he feels well and is not in pain. His vitals are within normal limits. Physical exam is notable for 1/5 strength upon dorsiflexion of the patient’s left foot, and 5/5 plantarflexion of the same foot. Which of the following initial injuries most likely occurred in this patient?
Q83
A 21-year-old man comes to the physician for a follow-up examination. Four days ago, he injured his right knee while playing soccer. Increased laxity of the right knee joint is noted when the knee is flexed to 30° and an abducting force is applied to the lower leg. The examination finding in this patient is most likely caused by damage to which of the following structures?
Q84
A 34-year-old woman comes to the physician because of a 3-month history of pain in her right thumb and wrist that radiates to her elbow. It is worse when she holds her infant son and improves with the use of an ice pack. Six months ago, she slipped on a wet floor and fell on her right outstretched hand. Her mother takes methotrexate for chronic joint pain. The patient takes ibuprofen as needed for her current symptoms. Examination of the right hand shows tenderness over the radial styloid with swelling but no redness. There is no crepitus. Grasping her right thumb and exerting longitudinal traction toward the ulnar side elicits pain. Range of motion of the finger joints is normal. There is no swelling, redness, or tenderness of any other joints. Which of the following is the most likely diagnosis?
Q85
A 37-year-old man presents to his primary care provider complaining of bilateral arm numbness. He was involved in a motor vehicle accident 3 months ago. His past medical history is notable for obesity and psoriatic arthritis. He takes adalimumab. His temperature is 99.3°F (37.4°C), blood pressure is 130/85 mmHg, pulse is 90/min, and respirations are 18/min. On exam, superficial skin ulcerations are found on his fingers bilaterally. His strength is 5/5 bilaterally in shoulder abduction, arm flexion, arm extension, wrist extension, finger abduction, and thumb flexion. He demonstrates loss of light touch and pinprick response in the distal tips of his 2nd and 5th fingertips and over the first dorsal web space. Vibratory sense is intact in the bilateral upper and lower extremities. Which of the following nervous system structures is most likely affected in this patient?
Q86
A 60-year-old woman is rushed to the emergency room after falling on her right elbow while walking down the stairs. She cannot raise her right arm. Her vital signs are stable, and the physical examination reveals loss of sensation over the upper lateral aspect of the right arm and shoulder. A radiologic evaluation shows a fracture of the surgical neck of the right humerus. Which of the following muscles is supplied by the nerve that is most likely damaged?
Q87
A 28-year-old man comes to the physician because of a 1-week history of weakness in the fingers of his right hand. One week ago, he experienced sudden pain in his right forearm during weight training. He has no history of serious illness. Physical examination shows impaired flexion of the proximal interphalangeal joints, while flexion of the distal interphalangeal joints is intact. Which of the following muscles is most likely injured?
Q88
A 17-year-old boy comes to the physician because of a 3-month history of pain in his right shoulder. He reports that he has stopped playing for his high school football team because of persistent difficulty lifting his right arm. Physical examination shows impaired active abduction of the right arm from 0 to 15 degrees. After passive abduction of the right arm to 15 degrees, the patient is able to raise his arm above his head. The dysfunctional muscle in this patient is most likely to be innervated by which of the following nerves?
Q89
A 28-year-old man comes to the physician because of a 3-month history of pain in his left shoulder. He is physically active and plays baseball twice a week. The pain is reproduced when the shoulder is externally rotated against resistance. Injury of which of the following tendons is most likely in this patient?
Q90
A 52-year-old female with a history of poorly-controlled diabetes presents to her primary care physician because of pain and tingling in her hands. These symptoms began several months ago and have been getting worse such that they interfere with her work as a secretary. She says that the pain is worse in the morning and she has been woken up at night by the pain. The tingling sensations have been located primarily in the thumb, index and middle fingers. On physical exam atrophy of the thenar eminence is observed and the pain is reproduced when the wrist is maximally flexed. The most likely cause of this patient's symptoms affects which of the nerves shown in the image provided?
Upper/Lower Limb US Medical PG Practice Questions and MCQs
Question 81: Seven hours after undergoing left hip arthroplasty for chronic hip pain, a 67-year-old woman reports a prickling sensation in her left anteromedial thigh and lower leg. Neurologic examination shows left leg strength 3/5 on hip flexion and 2/5 on knee extension. Patellar reflex is decreased on the left. Sensation to pinprick and light touch are decreased on the anteromedial left thigh as well as medial lower leg. Which of the following is the most likely underlying cause of this patient's symptoms?
A. Femoral nerve injury (Correct Answer)
B. L5 radiculopathy
C. Sural nerve injury
D. S1 radiculopathy
E. Fibular nerve injury
Explanation: ***Femoral nerve injury***
- The patient's symptoms—weakness in **hip flexion** (iliopsoas via femoral nerve) and **knee extension** (quadriceps via femoral nerve), decreased **patellar reflex** (femoral nerve), and sensory loss in the **anteromedial thigh** (femoral nerve) and **medial lower leg** (saphenous nerve, a branch of the femoral nerve)—are all consistent with femoral nerve dysfunction.
- **Hip arthroplasty procedures** can sometimes lead to iatrogenic femoral nerve damage due to retraction, compression, or direct injury during surgery, especially when positioning or using surgical instruments.
*L5 radiculopathy*
- L5 radiculopathy typically causes weakness in **foot dorsiflexion**, **eversion**, and **toe extension**, along with sensory loss over the **dorsum of the foot** and lateral lower leg, which does not match the patient's presentation.
- While it can cause hip abductor weakness, it would not explain the prominent **quadriceps weakness** and **decreased patellar reflex**.
*Sural nerve injury*
- The sural nerve provides sensation to the **posterolateral aspect of the lower leg** and lateral malleolus, and has no motor function to the hip or knee.
- Injury to this nerve would not account for the patient's **proximal weakness** or sensory loss in the anteromedial thigh.
*S1 radiculopathy*
- S1 radiculopathy typically leads to weakness in **plantarflexion**, **hip extension**, and an absent **Achilles reflex**, along with sensory loss over the lateral foot and sole.
- It would not explain the significant **quadriceps weakness**, **decreased patellar reflex**, or sensory changes in the anteromedial thigh.
*Fibular nerve injury*
- Fibular (peroneal) nerve injury primarily results in **foot drop** (weakness in dorsiflexion and eversion of the foot) and sensory loss over the **dorsum of the foot** and anterolateral lower leg.
- It does not affect hip flexion, knee extension, or the patellar reflex, nor does it cause sensory loss in the anteromedial thigh.
Question 82: A 25-year-old man presents to the emergency department after a car accident. He was the front seat restrained driver in a head-on collision. He has no significant past medical history. The patient’s vitals are stabilized and he is ultimately discharged with his injuries appropriately treated. At the patient’s follow up primary care appointment, he complains of being unable to lift his left foot. He otherwise states that he feels well and is not in pain. His vitals are within normal limits. Physical exam is notable for 1/5 strength upon dorsiflexion of the patient’s left foot, and 5/5 plantarflexion of the same foot. Which of the following initial injuries most likely occurred in this patient?
A. Lisfranc fracture
B. Calcaneal fracture
C. Tibial plateau fracture
D. Distal femur fracture
E. Fibular neck fracture (Correct Answer)
Explanation: ***Fibular neck fracture***
- A fracture of the **fibular neck** can damage the **common peroneal nerve**, which wraps around this region.
- Injury to the common peroneal nerve typically causes **foot drop** (inability to dorsiflex the foot) and sensory loss on the dorsum of the foot, matching the patient's symptoms of 1/5 strength upon dorsiflexion.
*Lisfranc fracture*
- This is an injury to the **midfoot tarsometatarsal joints**, often causing severe pain, swelling, and inability to bear weight.
- While it can occur in high-impact trauma, it primarily affects the **structural integrity of the foot** and does not directly cause isolated foot drop through nerve damage.
*Calcaneal fracture*
- A fracture of the **heel bone** typically results from axial loading injuries (e.g., falls from height), causing severe heel pain, swelling, and gait disturbance.
- It does not directly affect the common peroneal nerve or lead to isolated **foot drop**.
*Tibial plateau fracture*
- A fracture of the **proximal tibia** involves the knee joint and often results from significant valgus or varus force, presenting with knee pain, swelling, and instability.
- While it can be associated with soft tissue injuries, isolated **foot drop** via common peroneal nerve injury is less directly linked than with a fibular neck fracture.
*Distal femur fracture*
- A fracture of the **lower part of the thigh bone** typically presents with severe pain, swelling, and deformity of the thigh and knee, often due to significant trauma.
- This type of fracture is not directly associated with damage to the common peroneal nerve or isolated **foot drop**.
Question 83: A 21-year-old man comes to the physician for a follow-up examination. Four days ago, he injured his right knee while playing soccer. Increased laxity of the right knee joint is noted when the knee is flexed to 30° and an abducting force is applied to the lower leg. The examination finding in this patient is most likely caused by damage to which of the following structures?
A. Medial collateral ligament (Correct Answer)
B. Anterior cruciate ligament
C. Posterior cruciate ligament
D. Lateral collateral ligament
E. Lateral meniscus
Explanation: ***Medial collateral ligament***
- An abducting force applied to the lower leg (a **valgus stress**) when the knee is flexed to 30° tests the integrity of the MCL. Increased laxity indicates damage to this ligament.
- The MCL resists **valgus stress** and is commonly injured in contact sports, especially when a force is applied to the outside of the knee.
*Anterior cruciate ligament*
- The **anterior drawer test** and **Lachman test** (anterior translation of the tibia with the knee flexed) are used to assess ACL integrity.
- ACL injuries usually result from hyperextension, sudden stopping, or pivoting movements, leading to **anterior instability**.
*Posterior cruciate ligament*
- The **posterior drawer test** (posterior translation of the tibia with the knee flexed) is used to assess PCL integrity.
- PCL injuries typically occur from a direct blow to the tibia or an anterior force on the tibia, indicating **posterior instability**.
*Lateral collateral ligament*
- The LCL is assessed by applying an **adducting force** to the lower leg (a **varus stress**).
- Increased laxity during **varus stress** would indicate damage to the LCL.
*Lateral meniscus*
- Meniscal injuries are usually associated with clicking, locking, or catching sensations within the joint, and pain during twisting motions.
- Meniscal tears are primarily diagnosed using specific provocative tests like **McMurray's test** or **Apley's grind test**, not by assessing ligamentous laxity with abducting forces.
Question 84: A 34-year-old woman comes to the physician because of a 3-month history of pain in her right thumb and wrist that radiates to her elbow. It is worse when she holds her infant son and improves with the use of an ice pack. Six months ago, she slipped on a wet floor and fell on her right outstretched hand. Her mother takes methotrexate for chronic joint pain. The patient takes ibuprofen as needed for her current symptoms. Examination of the right hand shows tenderness over the radial styloid with swelling but no redness. There is no crepitus. Grasping her right thumb and exerting longitudinal traction toward the ulnar side elicits pain. Range of motion of the finger joints is normal. There is no swelling, redness, or tenderness of any other joints. Which of the following is the most likely diagnosis?
A. De Quervain tenosynovitis (Correct Answer)
B. Carpal tunnel syndrome
C. Swan neck deformity
D. Mallet finger
E. Stenosing tenosynovitis
Explanation: ***De Quervain tenosynovitis***
- The patient's symptoms of **radial-sided wrist pain** radiating to the elbow, worsened by activities involving thumb movement (like holding her infant), and tenderness over the **radial styloid** are classic for De Quervain tenosynovitis.
- The pain elicited by grasping the thumb and exerting traction toward the ulnar side (ulnar deviation of the wrist while the thumb is grasped - **Finkelstein's test**) is a pathognomonic finding for this condition.
*Carpal tunnel syndrome*
- Typically causes **numbness and tingling** in the thumb, index, middle, and radial half of the ring finger, often worse at night.
- Pain is usually in the **volar wrist** and does not primarily involve the radial styloid or produce a positive Finkelstein's test.
*Swan neck deformity*
- Characterized by **hyperextension of the PIP joint** and flexion of the DIP joint of the fingers, resulting in a characteristic S-shaped appearance.
- This is a **deformity** rather than an acute or subacute pain syndrome like the patient's presentation.
*Mallet finger*
- An injury to the **extensor tendon** of the finger, resulting in an inability to fully extend the DIP joint.
- There is no mention of a traumatic injury to the DIP joint or a persistent flexion deformity in this patient.
*Stenosing tenosynovitis*
- Also known as **trigger finger**, it involves **tendon sheath inflammation** that restricts the smooth gliding of tendons, typically causing catching or locking of a finger.
- This condition affects the **flexor tendons** and does not present with pain over the radial styloid or positive Finkelstein's test.
Question 85: A 37-year-old man presents to his primary care provider complaining of bilateral arm numbness. He was involved in a motor vehicle accident 3 months ago. His past medical history is notable for obesity and psoriatic arthritis. He takes adalimumab. His temperature is 99.3°F (37.4°C), blood pressure is 130/85 mmHg, pulse is 90/min, and respirations are 18/min. On exam, superficial skin ulcerations are found on his fingers bilaterally. His strength is 5/5 bilaterally in shoulder abduction, arm flexion, arm extension, wrist extension, finger abduction, and thumb flexion. He demonstrates loss of light touch and pinprick response in the distal tips of his 2nd and 5th fingertips and over the first dorsal web space. Vibratory sense is intact in the bilateral upper and lower extremities. Which of the following nervous system structures is most likely affected in this patient?
A. Cuneate fasciculus
B. Ventral horns
C. Anterior corticospinal tract
D. Spinocerebellar tract
E. Ventral white commissure (Correct Answer)
Explanation: ***Ventral white commissure***
- The patient presents with **bilateral loss of pain (pinprick) and light touch sensation** in the upper extremity fingertips, while **vibratory sense is intact** and **motor strength is fully preserved (5/5)**. This dissociated sensory loss pattern is pathognomonic for a lesion affecting the **ventral white commissure**.
- The ventral white commissure contains **decussating fibers of the spinothalamic tract**, which carry pain and temperature sensation from the contralateral body. A lesion here (classically seen in **syringomyelia** affecting the cervical spinal cord) causes **bilateral loss of pain and temperature sensation** in a characteristic distribution while **sparing the dorsal columns** (vibratory sense and proprioception remain intact) and motor pathways.
- The **superficial skin ulcerations** on his fingers are explained by chronic loss of protective pain sensation, leading to unnoticed repetitive trauma. The motor vehicle accident 3 months ago may have precipitated or worsened an underlying syrinx.
- This is the classic **"cape-like" or suspended sensory loss** pattern, though it can present with focal dermatomal involvement as in this case.
*Cuneate fasciculus*
- The cuneate fasciculus is part of the **dorsal column-medial lemniscal pathway** that carries **vibratory sense, proprioception, and fine discriminative touch** from the upper extremities.
- A lesion here would cause **loss of vibratory sense** and proprioception, which are explicitly **intact** in this patient, making this option incorrect.
*Ventral horns*
- The ventral horns contain **lower motor neuron cell bodies** that innervate skeletal muscles.
- Damage would cause **motor deficits** including weakness (reduced strength), muscle atrophy, and fasciculations, none of which are present in this patient who has normal 5/5 strength throughout.
*Anterior corticospinal tract*
- This tract mediates **voluntary motor control**, primarily of axial and proximal muscles.
- Lesions would result in **motor weakness or spasticity**, not the isolated sensory deficits seen in this patient.
*Spinocerebellar tract*
- The spinocerebellar tracts carry **unconscious proprioceptive information** to the cerebellum for motor coordination.
- Damage would manifest as **ataxia, dysmetria, and incoordination**, which are not described in this patient's presentation.
Question 86: A 60-year-old woman is rushed to the emergency room after falling on her right elbow while walking down the stairs. She cannot raise her right arm. Her vital signs are stable, and the physical examination reveals loss of sensation over the upper lateral aspect of the right arm and shoulder. A radiologic evaluation shows a fracture of the surgical neck of the right humerus. Which of the following muscles is supplied by the nerve that is most likely damaged?
A. Teres minor (Correct Answer)
B. Teres major
C. Subscapularis
D. Infraspinatus
E. Supraspinatus
Explanation: ***Teres minor***
- A fracture of the **surgical neck of the humerus** often damages the **axillary nerve**, which innervates the **teres minor**.
- The axillary nerve also supplies the **deltoid muscle** and provides cutaneous sensation to the **upper lateral arm**, consistent with the patient's sensory loss.
*Teres major*
- This muscle is innervated by the **lower subscapular nerve**, which is less likely to be damaged in a surgical neck fracture.
- Its primary action is **adduction** and **internal rotation** of the arm.
*Subscapularis*
- The **subscapularis** is innervated by the **upper and lower subscapular nerves**.
- While it contributes to internal rotation, its nerve supply is typically protected in this type of fracture.
*Infraspinatus*
- The **infraspinatus** muscle is innervated by the **suprascapular nerve**.
- This nerve is generally not affected by a fracture of the surgical neck of the humerus.
*Supraspinatus*
- Similar to the infraspinatus, the **supraspinatus** is also innervated by the **suprascapular nerve**.
- Damage to this nerve due to a humeral surgical neck fracture is uncommon.
Question 87: A 28-year-old man comes to the physician because of a 1-week history of weakness in the fingers of his right hand. One week ago, he experienced sudden pain in his right forearm during weight training. He has no history of serious illness. Physical examination shows impaired flexion of the proximal interphalangeal joints, while flexion of the distal interphalangeal joints is intact. Which of the following muscles is most likely injured?
A. Flexor carpi radialis
B. Flexor digitorum superficialis (Correct Answer)
C. Palmaris longus
D. Flexor carpi ulnaris
E. Flexor digitorum profundus
Explanation: **Flexor digitorum superficialis**
- Injury to the **flexor digitorum superficialis (FDS)** accounts for the impaired flexion of the **proximal interphalangeal (PIP) joints** as it is the primary flexor of these joints.
- The **intact flexion of the distal interphalangeal (DIP) joints** indicates that the **flexor digitorum profundus (FDP)**, which flexes the DIP joints, is still functional.
*Flexor carpi radialis*
- The **flexor carpi radialis** primarily acts to **flex and abduct the wrist**, not the finger joints.
- An injury would lead to weakness in wrist movements rather than isolated finger joint flexion issues.
*Palmaris longus*
- The **palmaris longus** is a weak flexor of the wrist and tenses the **palmar aponeurosis**.
- It does not contribute to the flexion of the interphalangeal joints of the fingers.
*Flexor carpi ulnaris*
- The **flexor carpi ulnaris** primarily **flexes and adducts the wrist**.
- Injury to this muscle would result in wrist movement deficits, not specific interphalangeal joint flexion dysfunction.
*Flexor digitorum profundus*
- The **flexor digitorum profundus (FDP)** is responsible for **flexion of the distal interphalangeal (DIP) joints** as well as assisting with PIP and metacarpophalangeal (MCP) joint flexion.
- Since flexion of the **DIP joints is intact**, the FDP is likely not injured.
Question 88: A 17-year-old boy comes to the physician because of a 3-month history of pain in his right shoulder. He reports that he has stopped playing for his high school football team because of persistent difficulty lifting his right arm. Physical examination shows impaired active abduction of the right arm from 0 to 15 degrees. After passive abduction of the right arm to 15 degrees, the patient is able to raise his arm above his head. The dysfunctional muscle in this patient is most likely to be innervated by which of the following nerves?
A. Long thoracic nerve
B. Suprascapular nerve (Correct Answer)
C. Upper subscapular nerve
D. Accessory nerve
E. Axillary nerve
Explanation: ***Suprascapular nerve***
- The patient exhibits impaired active abduction from 0 to 15 degrees but normal abduction after passive assistance, indicating dysfunction of the **supraspinatus muscle**.
- The **supraspinatus muscle** is responsible for **initiating shoulder abduction** from 0 to 15 degrees, after which the deltoid muscle takes over for continued abduction.
- The **suprascapular nerve** innervates both the **supraspinatus** and **infraspinatus muscles**, with the supraspinatus being crucial for the initial phase of abduction.
*Long thoracic nerve*
- This nerve innervates the **serratus anterior muscle**, which is responsible for **scapular protraction** and upward rotation.
- Damage to the long thoracic nerve would typically result in **winged scapula**, not difficulty in initiating abduction.
*Upper subscapular nerve*
- The upper subscapular nerve innervates the **subscapularis muscle**, part of the rotator cuff.
- This muscle is primarily involved in **internal rotation** of the shoulder and contributes to adduction, not abduction.
*Accessory nerve*
- The accessory nerve (cranial nerve XI) innervates the **sternocleidomastoid** and **trapezius muscles**.
- Damage to this nerve would most likely present with weakness in **shrugging the shoulders** or turning the head, not difficulty with shoulder abduction.
*Axillary nerve*
- This nerve innervates the **deltoid muscle** and the **teres minor muscle**, and provides sensory input from the shoulder joint and lateral arm.
- The deltoid is responsible for **shoulder abduction** from 15 to 90 degrees; a deficit here would affect a different range of motion than what is described.
Question 89: A 28-year-old man comes to the physician because of a 3-month history of pain in his left shoulder. He is physically active and plays baseball twice a week. The pain is reproduced when the shoulder is externally rotated against resistance. Injury of which of the following tendons is most likely in this patient?
A. Infraspinatus (Correct Answer)
B. Subscapularis
C. Pectoralis major
D. Supraspinatus
E. Teres major
Explanation: ***Infraspinatus***
- Pain during **external rotation against resistance** is a classic sign of infraspinatus tendon injury, as it is a primary muscle for this action.
- The patient's history of playing baseball and experiencing pain, especially with resistive external rotation, points to an injury of this **rotator cuff muscle**.
*Subscapularis*
- The subscapularis primarily causes **internal rotation** of the shoulder; injury would typically present with pain during resisted internal rotation, not external.
- While it is a rotator cuff muscle, its function does not align with the specific maneuver causing pain described in the patient.
*Pectoralis major*
- The pectoralis major is a large chest muscle involved primarily in **adduction**, **internal rotation**, and **flexion of the humerus**, not external rotation.
- Injury to this muscle would present with pain during these specific movements, not resisted external rotation.
*Supraspinatus*
- The supraspinatus is primarily involved in **initiation of abduction** and helps stabilize the shoulder joint, and pain would usually be elicited during these movements.
- While a common site of rotator cuff injury, its function does not directly cause pain with resisted external rotation as described.
*Teres major*
- The teres major acts as an **adductor** and **internal rotator** of the humerus, similar to the latissimus dorsi.
- Pain from a teres major injury would be associated with these actions, not with resisted external rotation.
Question 90: A 52-year-old female with a history of poorly-controlled diabetes presents to her primary care physician because of pain and tingling in her hands. These symptoms began several months ago and have been getting worse such that they interfere with her work as a secretary. She says that the pain is worse in the morning and she has been woken up at night by the pain. The tingling sensations have been located primarily in the thumb, index and middle fingers. On physical exam atrophy of the thenar eminence is observed and the pain is reproduced when the wrist is maximally flexed. The most likely cause of this patient's symptoms affects which of the nerves shown in the image provided?
A. D (Correct Answer)
B. A
C. B
D. C
E. E
Explanation: ***D***
- The patient's symptoms of pain and tingling in the **thumb, index, and middle fingers**, worse in the morning and at night, along with thenar atrophy and positive Phalen's sign (pain with maximal wrist flexion), are classic for **carpal tunnel syndrome**.
- **Carpal tunnel syndrome** is caused by compression of the **median nerve** (represented by D in the provided image).
*A*
- This nerve represents the **radial nerve**, which primarily innervates the extensors of the wrist and fingers and provides sensation to the posterior aspect of the forearm and hand.
- Compression or damage to the radial nerve typically causes "wrist drop" and sensory loss in a different distribution, not consistent with the patient's symptoms.
*B*
- This nerve represents the **ulnar nerve**, which innervates muscles of the hand (excluding those of the thenar eminence) and provides sensation to the little finger and half of the ring finger.
- Ulnar nerve compression (e.g., at the elbow in **cubital tunnel syndrome**) would lead to symptoms in the "pinky" and ring finger, and atrophy of the hypothenar eminence, which are not seen here.
*C*
- This nerve represents the **axillary nerve**, which innervates the deltoid and teres minor muscles and provides sensation over the lateral shoulder.
- Damage to the axillary nerve would result in shoulder weakness and sensory loss over the deltoid, far from the patient's hand symptoms.
*E*
- This nerve represents the **musculocutaneous nerve**, which innervates the biceps and brachialis muscles and provides sensation to the lateral forearm.
- Injury to this nerve would cause weakness in elbow flexion and sensory loss in the forearm, not hand pain and tingling in the specified distribution.