MSW EXAM 2025 QUESTIONS AND
ANSWERS
A 45-year-old woman is being examined as a candidate for cosmetic breast surgery. The
surgeon notes that both of her breasts sag considerably. Which structure has most likely
become stretched to result in this condition? - ANS Suspensory (Coopers) ligaments
The suspensory ligaments of the breast, also known as Coopers ligaments, are fibrous bands
that run from the dermis of the skin to the deep layer of superficial fascia and are primary
supports for the breasts against gravity. Ptosis of the breast is usually due to the stretching of
these ligaments and can be repaired with plastic surgery. Scarpas fascia is the deep
membranous layer of superficial fascia of the anterior abdominal wall. The pectoralis major and
pectoralis minor are muscles that move the upper limb and lie deep to the breast but do not
provide any direct support structure to the breast. The serratus anterior muscle is involved in
the movements of the scapula.
A 27-year-old man was admitted to the emergency department after an automobile collision in
which he suffered a fracture of the lateral border of the scapula. Six weeks after the accident,
physical examination reveals weakness in medial rotation and adduction of the humerus. Which
nerve was most likely injured? - ANS Lower subscapular
Lower subscapular nerves arise from the cervical spinal nerves 5 and 6. It innervates the
subscapularis and teres major muscles. The subscapularis and teres major are both responsible
for adducting and medially rotating the arm. A lesion of this nerve would result in weakness in
these motions. The axillary nerve also arises from cervical spinal nerves 5 and 6 and innervates
the deltoid and teres minor muscles. The deltoid muscle is large and covers the entire surface
of the shoulder, and contributes to arm movement in any plane. The teres minor is a lateral
rotator and a member of the rotator cuff group of muscles. The radial nerve arises from the
posterior cord of the brachial plexus. It is the largest branch, and it innervates the triceps
brachii and anconeus in the arm. The spinal accessory nerve is cranial nerve XI, and it innervates
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,the trapezius muscle, which elevates and depresses the scapula. The ulnar nerve arises from
the medial cord of the brachial plexus and runs down the medial aspect of the arm. It
innervates muscles of the forearm and hand.
A 48-year-old female court stenographer is admitted to the orthopedic clinic with symptoms of
carpal tunnel syndrome, with which she has suffered for almost a year. Which muscles most
typically become weakened in this condition? - ANS Thenar
The thenar muscles (and lumbricals I and II) are innervated by the median nerve, which runs
through the carpal tunnel. The carpal tunnel is formed anteriorly by the flexor retinaculum and
posteriorly by the carpal bones. Carpal tunnel syndrome is caused by a compression of the
median nerve, due to reduced space in the carpal tunnel. The carpal tunnel contains the
tendons of flexor pollicis longus, flexor digitorum profundus, and flexor digitorum superficialis
muscles. The dorsal interossei, lumbricals III and IV, palmar interossei, and hypothenar muscles
are all innervated by the ulnar nerve.
A 45-year-old male arrived at the emergency department with injuries to his left elbow after he
fell in a bicycle race. Radiographic and MRI examinations show a fracture of the medial
epicondyle and a torn ulnar nerve. Which of the following muscles would be most likely to be
paralyzed? - ANS Flexor carpi ulnaris
Fracture of the medial epicondyle often causes damage to the ulnar nerve due to its position in
the groove behind the epicondyle. The ulnar nerve innervates one and a half muscles in the
forearmthe flexor carpi ulnaris and the medial half of the flexor digitorum profundus. The nerve
continues on to innervate muscles in the hand. The flexor digitorum superficialis is innervated
by the median nerve and the biceps brachii by the musculocutaneous. The radial nerve
innervates both the brachioradialis and supinator muscles.
While walking to his classroom building, a first-year medical student slipped on the wet
pavement and fell against the curb, injuring his right arm. Radiographic images showed a
midshaft fracture of the humerus. Which pair of structures was most likely injured at the
fracture site? - ANS Radial nerve and deep brachial artery
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,A midshaft humeral fracture can result in injury to the radial nerve and deep brachial artery
because they lie in the spiral groove located in the midshaft. Injury to the median nerve and
brachial artery can be caused by a supracondylar fracture that occurs by falling on an
outstretched hand and partially flexed elbow. A fracture of the surgical neck of the humerus
can injure the axillary nerve and posterior humeral circumflex artery. The suprascapular artery
and nerve can be injured in a shoulder dislocation. The long thoracic nerve and lateral thoracic
artery may be damaged during a mastectomy procedure.
An 18-year-old male is brought to the emergency department after an injury while playing
rugby. Imaging reveals a transverse fracture of the humerus about 1 inch proximal to the
epicondyles. Which nerve is most frequently injured by the jagged edges of the broken bone at
this location? - ANS Median
A supracondylar fracture often results in injury to the median nerve. The course of the median
nerve is anterolateral, and at the elbow it lies medial to the brachial artery on the brachialis
muscle. The axillary nerve passes posteriorly through the quadrangular space, accompanied by
the posterior circumflex humeral artery, and winds around the surgical neck of the humerus.
Injury to the surgical neck may damage the axillary nerve. The musculocutaneous nerve pierces
the coracobrachialis muscle and descends between the biceps and brachialis muscle. It
continues into the forearm as the lateral antebrachial cutaneous nerve. The ulnar nerve
descends behind the medial epicondyle in its groove and is easily injured and produces funny
bone symptoms.
A 52-year-old band director suffered problems in her right arm several days after strenuous
field exercises for a major athletic tournament. Examination in the orthopedic clinic reveals
wrist drop and weakness of grasp but normal extension of the elbow joint. There is no loss of
sensation in the affected limb. Which nerve was most likely affected? - ANS Posterior
interosseous
The radial nerve descends posteriorly between the long and lateral heads of the triceps and
passes inferolaterally on the back of the humerus between the medial and lateral heads of the
triceps. It eventually enters the anterior compartment and descends to enter the cubital fossa,
where it divides into superficial and deep branches. The deep branch of the radial nerve winds
laterally around the radius and runs between the two heads of the supinator and continues as
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, the posterior interosseous nerve, innervating extensor muscles of the forearm. Because this
injury does not result in loss of sensation over the skin of the upper limb, it is likely that the
superficial branch of the radial nerve is not injured. If the radial nerve were injured very
proximally, the woman would not have extension of her elbow. The branches of the radial
nerve to the triceps arise proximal to where the nerve runs in the spiral groove. The anterior
interosseous nerve arises from the median nerve and supplies the flexor digitorum profundus,
flexor pollicis longus, and pronator quadratus, none of which seem to be injured in this
example. Injury to the median nerve causes a characteristic flattening (atrophy) of the thenar
eminence.
A 32-year-old woman is admitted to the emergency department after an automobile collision.
Radiographic examination reveals multiple fractures of the humerus. Flexion and supination of
the forearm are severely weakened. She also has loss of sensation on the lateral surface of the
forearm. Which of the following nerves has most likely been injured? -
ANS Musculocutaneous
The musculocutaneous nerve supplies the biceps brachii and brachialis, which are the flexors of
the forearm at the elbow. The musculocutaneous nerve continues as the lateral antebrachial
cutaneous nerve, which supplies sensation to the lateral side of the forearm (with the forearm
in the anatomic position). The biceps brachii is the most powerful supinator muscle. Injury to
this nerve would result in weakness of supination and forearm flexion and lateral forearm
sensory loss. Injury to the radial nerve would result in weakened extension and a characteristic
wrist drop. Injury to the median nerve causes paralysis of flexor digitorum superficialis and
other flexors in the forearm and results in a characteristic flattening of the thenar eminence.
The lateral cord of the brachial plexus gives origin both to the musculocutaneous and lateral
pectoral nerves. There is no indication of pectoral paralysis or weakness. Injury to the lateral
cord can result in weakened flexion and supination in the forearm, and weakened adduction
and medial rotation of the arm. The lateral cutaneous nerve of the forearm is a branch of the
musculocutaneous nerve and does not supply any motor innervation. Injury to the
musculocutaneous nerve alone is unusual but can follow penetrating injuries.
A 24-year-old medical student was bitten at the base of her thumb by her dog. The wound
became infected and the infection spread into the radial bursa. The tendon(s) of which muscle
will most likely be affected? - ANS Flexor pollicis longus
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ANSWERS
A 45-year-old woman is being examined as a candidate for cosmetic breast surgery. The
surgeon notes that both of her breasts sag considerably. Which structure has most likely
become stretched to result in this condition? - ANS Suspensory (Coopers) ligaments
The suspensory ligaments of the breast, also known as Coopers ligaments, are fibrous bands
that run from the dermis of the skin to the deep layer of superficial fascia and are primary
supports for the breasts against gravity. Ptosis of the breast is usually due to the stretching of
these ligaments and can be repaired with plastic surgery. Scarpas fascia is the deep
membranous layer of superficial fascia of the anterior abdominal wall. The pectoralis major and
pectoralis minor are muscles that move the upper limb and lie deep to the breast but do not
provide any direct support structure to the breast. The serratus anterior muscle is involved in
the movements of the scapula.
A 27-year-old man was admitted to the emergency department after an automobile collision in
which he suffered a fracture of the lateral border of the scapula. Six weeks after the accident,
physical examination reveals weakness in medial rotation and adduction of the humerus. Which
nerve was most likely injured? - ANS Lower subscapular
Lower subscapular nerves arise from the cervical spinal nerves 5 and 6. It innervates the
subscapularis and teres major muscles. The subscapularis and teres major are both responsible
for adducting and medially rotating the arm. A lesion of this nerve would result in weakness in
these motions. The axillary nerve also arises from cervical spinal nerves 5 and 6 and innervates
the deltoid and teres minor muscles. The deltoid muscle is large and covers the entire surface
of the shoulder, and contributes to arm movement in any plane. The teres minor is a lateral
rotator and a member of the rotator cuff group of muscles. The radial nerve arises from the
posterior cord of the brachial plexus. It is the largest branch, and it innervates the triceps
brachii and anconeus in the arm. The spinal accessory nerve is cranial nerve XI, and it innervates
COPYRIGHT © 2025 THESTAR ALL RIGHTS RESERVED 1
,the trapezius muscle, which elevates and depresses the scapula. The ulnar nerve arises from
the medial cord of the brachial plexus and runs down the medial aspect of the arm. It
innervates muscles of the forearm and hand.
A 48-year-old female court stenographer is admitted to the orthopedic clinic with symptoms of
carpal tunnel syndrome, with which she has suffered for almost a year. Which muscles most
typically become weakened in this condition? - ANS Thenar
The thenar muscles (and lumbricals I and II) are innervated by the median nerve, which runs
through the carpal tunnel. The carpal tunnel is formed anteriorly by the flexor retinaculum and
posteriorly by the carpal bones. Carpal tunnel syndrome is caused by a compression of the
median nerve, due to reduced space in the carpal tunnel. The carpal tunnel contains the
tendons of flexor pollicis longus, flexor digitorum profundus, and flexor digitorum superficialis
muscles. The dorsal interossei, lumbricals III and IV, palmar interossei, and hypothenar muscles
are all innervated by the ulnar nerve.
A 45-year-old male arrived at the emergency department with injuries to his left elbow after he
fell in a bicycle race. Radiographic and MRI examinations show a fracture of the medial
epicondyle and a torn ulnar nerve. Which of the following muscles would be most likely to be
paralyzed? - ANS Flexor carpi ulnaris
Fracture of the medial epicondyle often causes damage to the ulnar nerve due to its position in
the groove behind the epicondyle. The ulnar nerve innervates one and a half muscles in the
forearmthe flexor carpi ulnaris and the medial half of the flexor digitorum profundus. The nerve
continues on to innervate muscles in the hand. The flexor digitorum superficialis is innervated
by the median nerve and the biceps brachii by the musculocutaneous. The radial nerve
innervates both the brachioradialis and supinator muscles.
While walking to his classroom building, a first-year medical student slipped on the wet
pavement and fell against the curb, injuring his right arm. Radiographic images showed a
midshaft fracture of the humerus. Which pair of structures was most likely injured at the
fracture site? - ANS Radial nerve and deep brachial artery
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,A midshaft humeral fracture can result in injury to the radial nerve and deep brachial artery
because they lie in the spiral groove located in the midshaft. Injury to the median nerve and
brachial artery can be caused by a supracondylar fracture that occurs by falling on an
outstretched hand and partially flexed elbow. A fracture of the surgical neck of the humerus
can injure the axillary nerve and posterior humeral circumflex artery. The suprascapular artery
and nerve can be injured in a shoulder dislocation. The long thoracic nerve and lateral thoracic
artery may be damaged during a mastectomy procedure.
An 18-year-old male is brought to the emergency department after an injury while playing
rugby. Imaging reveals a transverse fracture of the humerus about 1 inch proximal to the
epicondyles. Which nerve is most frequently injured by the jagged edges of the broken bone at
this location? - ANS Median
A supracondylar fracture often results in injury to the median nerve. The course of the median
nerve is anterolateral, and at the elbow it lies medial to the brachial artery on the brachialis
muscle. The axillary nerve passes posteriorly through the quadrangular space, accompanied by
the posterior circumflex humeral artery, and winds around the surgical neck of the humerus.
Injury to the surgical neck may damage the axillary nerve. The musculocutaneous nerve pierces
the coracobrachialis muscle and descends between the biceps and brachialis muscle. It
continues into the forearm as the lateral antebrachial cutaneous nerve. The ulnar nerve
descends behind the medial epicondyle in its groove and is easily injured and produces funny
bone symptoms.
A 52-year-old band director suffered problems in her right arm several days after strenuous
field exercises for a major athletic tournament. Examination in the orthopedic clinic reveals
wrist drop and weakness of grasp but normal extension of the elbow joint. There is no loss of
sensation in the affected limb. Which nerve was most likely affected? - ANS Posterior
interosseous
The radial nerve descends posteriorly between the long and lateral heads of the triceps and
passes inferolaterally on the back of the humerus between the medial and lateral heads of the
triceps. It eventually enters the anterior compartment and descends to enter the cubital fossa,
where it divides into superficial and deep branches. The deep branch of the radial nerve winds
laterally around the radius and runs between the two heads of the supinator and continues as
COPYRIGHT © 2025 THESTAR ALL RIGHTS RESERVED 3
, the posterior interosseous nerve, innervating extensor muscles of the forearm. Because this
injury does not result in loss of sensation over the skin of the upper limb, it is likely that the
superficial branch of the radial nerve is not injured. If the radial nerve were injured very
proximally, the woman would not have extension of her elbow. The branches of the radial
nerve to the triceps arise proximal to where the nerve runs in the spiral groove. The anterior
interosseous nerve arises from the median nerve and supplies the flexor digitorum profundus,
flexor pollicis longus, and pronator quadratus, none of which seem to be injured in this
example. Injury to the median nerve causes a characteristic flattening (atrophy) of the thenar
eminence.
A 32-year-old woman is admitted to the emergency department after an automobile collision.
Radiographic examination reveals multiple fractures of the humerus. Flexion and supination of
the forearm are severely weakened. She also has loss of sensation on the lateral surface of the
forearm. Which of the following nerves has most likely been injured? -
ANS Musculocutaneous
The musculocutaneous nerve supplies the biceps brachii and brachialis, which are the flexors of
the forearm at the elbow. The musculocutaneous nerve continues as the lateral antebrachial
cutaneous nerve, which supplies sensation to the lateral side of the forearm (with the forearm
in the anatomic position). The biceps brachii is the most powerful supinator muscle. Injury to
this nerve would result in weakness of supination and forearm flexion and lateral forearm
sensory loss. Injury to the radial nerve would result in weakened extension and a characteristic
wrist drop. Injury to the median nerve causes paralysis of flexor digitorum superficialis and
other flexors in the forearm and results in a characteristic flattening of the thenar eminence.
The lateral cord of the brachial plexus gives origin both to the musculocutaneous and lateral
pectoral nerves. There is no indication of pectoral paralysis or weakness. Injury to the lateral
cord can result in weakened flexion and supination in the forearm, and weakened adduction
and medial rotation of the arm. The lateral cutaneous nerve of the forearm is a branch of the
musculocutaneous nerve and does not supply any motor innervation. Injury to the
musculocutaneous nerve alone is unusual but can follow penetrating injuries.
A 24-year-old medical student was bitten at the base of her thumb by her dog. The wound
became infected and the infection spread into the radial bursa. The tendon(s) of which muscle
will most likely be affected? - ANS Flexor pollicis longus
COPYRIGHT © 2025 THESTAR ALL RIGHTS RESERVED 4
