Brachial Plexus Lesions

Question 1

Erb palsy (“waiter’s tip”)

Answer 1

Traction or tear of upper (“Erb-er”) trunk: C5-C6 roots

Infants—lateral traction on neck during delivery
Adults—trauma

Deltoid, supraspinatus
-arm hangs by side

Infraspinatus
-arm medially rotated

Biceps brachii Flexion
-arm extended and pronated

Question 2

Klumpke palsy

Answer 2

Traction or tear of lower trunk: C8-T1 root

Infants—upward force on arm during delivery
Adults—trauma (eg, grabbing a tree branch to break a fall)

Total claw hand

Question 3

Thoracic outlet syndrome

Answer 3

Compression of lower trunk
and subclavian vessels

Cervical rib
Pan coast tumor

Atrophy of intrinsic hand muscles; ischemia, pain, and edema due to vascular compression

Question 4

Winged scapula

Answer 4

Lesion of long thoracic nerve

Axillary node dissection after mastectomy
stab wounds

Serrates anterior

Inability to anchor scapula to thoracic cage–>cannot abduct arm above horizontal position