Ch 6-Brachial Plexus

Question 1

order of the Brachial Plexus (C5-T1):

Randy Travis Drinks Cold Beer

Answer 1

Roots, Trunks, Divisions, Cords, Branches

Question 2

Common brachial plexus injuries

Answer 2

Erb’s palsy- involvement of C5/6

Klumpke’s palsy- C8, T1 (sometimes C7)

Question 3

Common areas of compression

Answer 3

Thoracic outlet syndrome- interscalene triangle (b/w anterior/middle scalene) *listen at 38.45 brachial plexus rec
Costoclavicular space- 1st rib & clavicle
Subcoracoid space- underneath pectoralis minor

Question 4

Common areas of Median nerve compression

Answer 4

*Pronator teres (pronator syndrome), *transverse carpal ligament (most important, involved in carpal tunnel syndrome),

“Ape hand”, “sign of benediction”

Ligament of struthers, biceps aponeurosis, flexor digitorum superficialis

Question 5

Carpal tunnel syndrome

Answer 5

compression of median nerve by the transverse carpal ligament

• thenar muscles affected because of the recurrent branch of the median nerve can cause thenar wasting
• biggest functional implication- loss of opposition
• also leads to numbness/tingling of thumb, index, middle, and radial half of ring finger

Question 6

Common areas of compression of Ulnar nerve

Answer 6

cubital tunnel, Guyon’s canal, arcade of struthers, medial inter muscular septum, subluxing medial head of triceps, flexor carpi ulnaris

Question 7

Cubital tunnel syndrome

Guyon canal compression

Answer 7

• compression of ulnar nerve at cubital tunnel, at elbow ulnar side
• compression of ulnar nerve at guyon’s canal, above the wrist ulnar side

ulnar nerve compression leads to clawing of ring and small fingers-> the lower the compression the more clawing present

Question 8

Common areas of compression of radial nerve

Answer 8

Radial groove/spiral groove,

lateral intermuscular septum, fibrous band of brachioradialis, between brachial is and ECRB, Leash of Henry, Arcade of Fohse, Supinator, Distal brachioradialis

Question 9

Radial nerve palsy

Answer 9

compression of the radial nerve leads to wrist drop (inability to extend wrist, fingers, and thumb), referred to as “saturday night palsy”, most common place of compression is at the humerus (radial groove)

Question 10

Thenar muscles

Answer 10

Abductor pollicis brevis, flexor pollicis brevis, opponens pollicis brevis (AFO)

Question 11

Dermatomes

Answer 11

in an area of skin that is mainly supplied by a single spinal nerve (sensation)

Question 12

Myotomes

Answer 12

group of muscles that a single nerve root innervates (motor action)

Question 13

Muscle actions resulted from myotomes
C1/C2:
C3:
C4:
C5:
C6:
C7:
C8:
T1:
L2:
L3:
L4:
L5:
S1:

S2:
S3-4:

Answer 13

testing in clinic, want person to do these specific motions

• neck flexion/extension
• neck lateral flexion
• shoulder elevation
• shoulder abduction
• elbow flexion/wrist extension
• elbow extension/wrist flexion
• finger flexion
• finger abduction
• hip flexion
• knee extension
• ankle dorsiflexion
• great toe extension
• ankle plantar flexion/ankle eversion/hip extension
• knee flexion
• perineal reflex

Question 14

Dermatome actions
C5:
C6:
C7:
C8:
T1:
T3:
T4:

T6:
T10:
T12:
L2:
L3:
L4:
L5:
S1:
S2:
S3:

Answer 14

• anteriolateral shoulder
• thumb
• middle finger
• little finger
• medial arm
• 3rd, 4th interspace
• nipple line, 4th, 5th interspace
• xiphoid process
• navel
• pubis
• medial thigh
• medial knee
• medial ankle, great toe
• dorsum of foot
• lateral foot
• posteromedial thigh
• 4, 5 perineal area