Usmle Step 1 Fa Musculoskeletal Brachial/lumbosacral Plexus

Front 1

Injured nerve: fracture of surgical neck

Back 1

Axillary n.

Front 2

Injured nerve: dislocation of humerus

Back 2

Axillary n

Front 3

Injured root: cervical disk lesion

Back 3

C7 root

Front 4

Injured nerve: midshaft fracture of humerus

Back 4

Radial n in spiral groove

Front 5

Injured nerve: subluxation of radius

Back 5

Radial n (deep branch)

Front 6

Injured nerve: superficial laceration of palm

Back 6

Recurrent branch of median n

Front 7

Injured nerve: trauma to heel of hand

Back 7

Ulnar n

Front 8

Injured nerve: fracture o fhook of hamate

Back 8

Ulnar n

Front 9

Injured nerve: carpal tunnel syndrome

Back 9

Median n

Front 10

Injured nerve: dislocated lunate

Back 10

Median n

Front 11

Injured nerve: fracture of medial epicondyle of humerus

Back 11

Ulnar n

Front 12

Injured nerve: supracondylar fracture of humerus

Back 12

Median n

Front 13

Injured nerve: incorrect use of a crutch

Back 13

Radial n

Front 14

Injured nerve(s) : Cervical rib

Back 14

Lower trunk of brachial plexus

Front 15

Injured nerve (s): pancoast tumor

Back 15

Lower trunk of brachial plexus

Front 16

Erb Duchenne Palsy

Back 16

Traction or tear of upper trunk of brachial plexus (C5-C6); blow to shoulder or trauma during delivery
-Limb hangs by side (paralysis of abductors), medially rotated (paralysis of lateral rotators), pronated (loss of biceps)

Front 17

Klympke's palsy and thoracic outlet syndrome

Back 17

Embryologic or childbirth defect affecting inferior trunk of brachial plexus (C8, T1)
Cervical rib can compress subclav a and infer trunk resulting in thoracic outlet syndrome.

Front 18

Thoracic outlet syndrome

Back 18

(1) atrophy of thenar and hypothenar eminence
(2) atrophy of interosseous mucles
(3) sensory deficits on medial side of forearm and hand

Front 19

Ulnar claw

Back 19

Distal ulnar lesion "pope's blessing"
Loss of medial lumbrical fct; 4th and 5th digits are clawed

Front 20

Median claw

Back 20

Distal median nerve lesion (after branch w/C5-C6 branch off to feed forearm flexors)
Loss of lateral lumbrical fct; 2nd and 3rd digits clawed

Front 21

Ape hand

Back 21

Proximal median n lesion
Loss of opponens pollicis muscle fct
Unopposabl thumb (inability to abduct thumb)

Front 22

Klumpke's total claw

Back 22

Lesion of lower trunk C8 T1 of brachial plexus
Loss of fct of all lumbricals; forarm finger flexors (fed by part of median n w/C5-C7) and finger extensors (fed by radial n) unopposed; leads to clawing of digits

Front 23

Wrist drop

Back 23

Radial n injury
Provides innervation of brachioradialis, extensors of wrist and fingers, supinator, and triceps

Front 24

Thenar muscles

Back 24

Opponens pollicis, Abductor pollicis brevis, Flexor pollicis brevis

Front 25

Hypothenar muscles

Back 25

Opponens digiti minimi, abductor digiti minimi, flexor digiti minimi

Front 26

Dorsal interosseous muscles fct

Back 26

Abduct fingers

Front 27

Palmar interosseous muscles

Back 27

Adduct fingers

Front 28

Lumbrical muscles

Back 28

Flex at MP joint

Front 29

Repetive elbow trauma

Back 29

Leads to tiny tears in tendons and muscles; may be inflammatory
Lateral epicondylitis (tennis elbow)
Medial epicondylitis (golf elbow)

Front 30

Axillary n (roots)

Back 30

5,6

Front 31

Axillary nerve motor

Back 31

Arm abduction at shoulder

Front 32

Axillary nerve sensory

Back 32

Over deltoid

Front 33

Radial nerve roots

Back 33

5-8

Front 34

Radial nerve motor

Back 34

Wrist extension
Finger extension at mcp
Supination
Thumb extension/abduction

Front 35

Radial nerve sensory deficit

Back 35

Post arm and dorasal hand and thumb

Front 36

Median nerve roots

Back 36

6,8,T1

Front 37

Median nerve motor deficit (proximal injury)

Back 37

opposition of thumb

Front 38

Median nerve sensory (proximal injury)

Back 38

Dorsal palm, later 3/5 fingers and thenar eminence

Front 39

"Ape hand"

Back 39

Median nerve damage (proximal)

Front 40

Median nerve motor deficit (distal injury)

Back 40

lateral finger flexion
Wrist flexion

Front 41

Median nerve sensory deficit (distal injury)

Back 41

Dorsal and palmer aspects of lateral 3.5 fingers

Front 42

"pope's blessing"

Back 42

Distal damage to median n

Front 43

Ulnar n motor deficit (proximal)

Back 43

Medial finger flexion
Wrist flexion

Front 44

Ulnar n sensory deficit (proximal or distal)

Back 44

Medial 1.5 fingers, hypothenar eminence

Front 45

Ulnar n "sign" (proximal vs distal)

Back 45

Proximal: radial deviation upon wrist extension
Distal: ulbar claw hand (when asked to straighten fingers)

Front 46

Musculocutaneous nerve roots

Back 46

C5-7

Front 47

Musculocutaneous n motor deficit

Back 47

Flexion of arm and elbow

Front 48

Musculocutaneous n sensory deficit

Back 48

Lateral arm

Front 49

Obduratory nerve roots

Back 49

L2--4

Front 50

Cause of injury to obduratory nerve

Back 50

Anterior hip dislocation

Front 51

Motor deficit in obduratory nerve injury

Back 51

Thigh adduction

Front 52

Sensory deficit in obduratory nerve injury

Back 52

Medial thigh

Front 53

Femoral nerve roots

Back 53

L2-L4

Front 54

Cause of injury to femoral nerve

Back 54

Pelvic fracture

Front 55

Motor deficit in femoral nerve injury

Back 55

Thigh flexion
Leg extension

Front 56

Common peroneal nerve roots

Back 56

L4,5, S1, S2

Front 57

Cause of injury to common peroneal nerve

Back 57

trauma to lateral aspect of leg or fibula fracture

Front 58

Motor deficit seen in common peroneal nerve damage

Back 58

Foo eversion and dorsiflexion
Toe extension

Front 59

Sensory deficit seen in common peroneal nerve damage

Back 59

Anterolateral leg and dorsal foot

Front 60

Tibial nerve roots

Back 60

L4-S3

Front 61

Cause of injury to tibial nerve

Back 61

Knee trauma

Front 62

Motor deficit seen in tibial nerve damage

Back 62

Foot inversion and plantar flexion
Toe flexion

Front 63

Sensory deficit seen in tibial nerve damage

Back 63

Sole of foot

Front 64

Superior gluteal roots

Back 64

L4,L5, S1

Front 65

Cause of injury to superior gluteal n

Back 65

Post hip dislocation or polio

Front 66

Motor deficit seen in superior gluteal nerve injury

Back 66

Thigh abduction "trendelenberg's sign"

Front 67

Inferior gluteal n roots

Back 67

L5, S1, S2

Front 68

Cause o finjury to superior gluteal nerve roots

Back 68

Posterior hip dislocation

Front 69

Motor deficit seen in superior gluteal nerve injury

Back 69

Can't jump, climb stairs, or stand from sitting

Front 70

Nerve providing sensory to side of foot (dorsal)

Back 70

Sural n

Front 71

Nerve providing sensory to dorsal of foot and anterolateral leg?

Back 71

Superficial peroneal

Front 72

Nerve providing sensory to web b/w big and 2nd toe

Back 72

Deep peroneal

Front 73

Nerve providing sensory to plantar toe and medial ball of foot?

Back 73

Deep peroneal

Front 74

Nerve providing sensory to medial heel

Back 74

Tibial

Front 75

Nerve providing sensory to lateral plant portion of foot?

Back 75

Superficial peroneal

Front 76

Nerve providing sensory to back of lower limb?

Back 76

Saphenous (branch of femoral)