Erb-Duchenne palsy vs Klumpke palsy
How to tell Erb-Duchenne palsy and Klumpke palsy apart when a board question makes them look alike.
Erb-Duchenne (C5 to C6): waiter's tip from upper-trunk injury; Klumpke (C8 to T1): claw hand from lower-trunk injury, sometimes with Horner.
Side by side
Erb-Duchenne palsy injures upper trunk C5-C6 causing waiter tip posture with impaired abduction, external rotation, and elbow flexion.
Klumpke palsy injures lower trunk C8-T1 causing claw hand and may involve Horner syndrome if T1 sympathetic fibers are affected.
Erb-Duchenne palsy injures upper trunk C5-C6 causing waiter tip posture with impaired abduction, external rotation, and elbow flexion.
Klumpke palsy injures lower trunk C8-T1 causing claw hand and may involve Horner syndrome if T1 sympathetic fibers are affected.
Shoulder dystocia or downward traction at birth, absent Moro on that side, preserved grasp reflex, and waiter tip posture support Erb-Duchenne palsy.
Upward traction on an abducted arm, preserved shoulder movement, weak intrinsic hand muscles with claw hand, and ptosis with miosis if T1 is involved support Klumpke palsy.
The trap
Both are obstetric brachial plexus injuries from difficult delivery, but the mechanism and clinical pattern decide. Lateral neck traction (shoulder dystocia, breech delivery) injures the upper roots and produces Erb palsy (proximal arm weakness, waiter's tip). Arm hyperabduction (breech with arm above head) injures the lower roots and produces Klumpke palsy (intrinsic hand muscle weakness, claw hand, possible Horner). Most obstetric brachial plexus injuries recover spontaneously by 6 months; persistent deficits beyond 6 to 12 months may need microsurgical nerve repair.
Watch it explained
Test it nowThe repair move
Before naming the answer, force the stem through the separator: Erb is C5-C6 waiter tip; Klumpke is C8-T1 claw hand with possible Horner.
Try a free question
CoreA newborn delivered with shoulder dystocia has an arm that hangs limp at the side, internally rotated at the shoulder, extended at the elbow, with the forearm pronated and wrist flexed ('waiter's tip posture'). The Moro reflex is absent on that side. Which brachial plexus injury is this?
Show answer and explanation
Answer: A. Erb-Duchenne palsy. Erb-Duchenne palsy is upper brachial plexus injury (C5-C6 nerve roots) from excessive LATERAL traction on the neck during difficult delivery (shoulder dystocia) or fall on the shoulder. Classic 'waiter's tip posture': arm extended at elbow, internally rotated at shoulder, forearm pronated, wrist flexed. Paralysis of deltoid (shoulder abduction), biceps and brachialis (elbow flexion), supraspinatus/infraspinatus (shoulder external rotation). Moro reflex absent on affected side.
Why the other choices are tempting
- B. Klumpke palsy is LOWER trunk (C8-T1) injury with claw hand and possible Horner syndrome.
- C. Total brachial plexus palsy paralyzes the entire arm.
- D. Phrenic nerve injury affects the diaphragm (respiratory), not the arm posture.
- E. Spinal cord injury would affect more body regions.
Flashcards
Tap a card to flip it.
What clue supports Erb-Duchenne palsy?
Choose Erb-Duchenne palsy when the stem gives this pattern: Erb-Duchenne palsy injures upper trunk C5-C6 causing waiter tip posture with impaired abduction, external rotation, and elbow flexion.
What clue supports Klumpke palsy?
Choose Klumpke palsy when the stem gives this contrasting pattern: Klumpke palsy injures lower trunk C8-T1 causing claw hand and may involve Horner syndrome if T1 sympathetic fibers are affected.
Quick answers
What is the fastest way to tell Erb-Duchenne palsy from Klumpke palsy?
Erb-Duchenne (C5 to C6): waiter's tip from upper-trunk injury; Klumpke (C8 to T1): claw hand from lower-trunk injury, sometimes with Horner.
What is the key clue for Erb-Duchenne palsy?
Erb-Duchenne palsy injures upper trunk C5-C6 causing waiter tip posture with impaired abduction, external rotation, and elbow flexion.
What is the key clue for Klumpke palsy?
Klumpke palsy injures lower trunk C8-T1 causing claw hand and may involve Horner syndrome if T1 sympathetic fibers are affected.
What is the common trap with Erb-Duchenne palsy vs Klumpke palsy?
Both are obstetric brachial plexus injuries from difficult delivery, but the mechanism and clinical pattern decide. Lateral neck traction (shoulder dystocia, breech delivery) injures the upper roots and produces Erb palsy (proximal arm weakness, waiter's tip). Arm hyperabduction (breech with arm above head) injures the lower roots and produces Klumpke palsy (intrinsic hand muscle weakness, claw hand, possible Horner). Most obstetric brachial plexus injuries recover spontaneously by 6 months; persistent deficits beyond 6 to 12 months may need microsurgical nerve repair.