Erb’s Palsy vs. Klumpke’s Palsy: Brachial Plexus Injuries Explained

Obstetric Brachial Plexus Injuries (OBPI) occur during difficult childbirth, usually due to traction on the baby's neck or arm. The presentation depends entirely on which nerve roots are damaged. The two most common types—Erb’s Palsy (Upper Plexus) and Klumpke’s Palsy (Lower Plexus)—have distinct postures, sensory deficits, and prognoses. This guide compares them side-by-side for students and clinicians.

1. High-Yield Comparison: Erb's vs. Klumpke's

Feature	Erb’s Palsy (Erb-Duchenne)	Klumpke’s Palsy (Dejerine-Klumpke)
Nerve Roots	C5, C6 (Upper Trunk)	C8, T1 (Lower Trunk)
Mechanism	Lateral traction on neck (shoulder dystocia - head pulled away from shoulder).	Hyper-abduction of arm (arm pulled overhead) during delivery.
Muscles Affected	Deltoid, Biceps, Brachialis, Supraspinatus, Infraspinatus, Supinator.	Intrinsic hand muscles (Interossei, Thenar, Hypothenar), Wrist flexors.
Deformity Name	"Waiter’s Tip" (Policeman’s Tip)	"Claw Hand"
Sensory Loss	Lateral aspect of arm, forearm, thumb.	Medial aspect of forearm, ulnar side of hand (little finger).
Reflexes	Biceps & Supinator jerks absent. Moro reflex absent/asymmetrical.	Grasp reflex absent.
Prevalence	Common (~75-80% of cases).	Rare (< 2% of cases).

2. Erb’s Palsy: The "Waiter's Tip"

This injury occurs at Erb's Point, where the C5 and C6 roots join. It primarily affects the shoulder and elbow.

The Classic Deformity

The arm hangs by the side in a specific posture due to muscle imbalance:

• Shoulder: Adducted & Internally Rotated (Loss of Deltoid/Rotator Cuff).
• Elbow: Extended (Loss of Biceps/Brachialis).
• Forearm: Pronated (Loss of Supinator/Biceps).
• Wrist: Flexed (Often due to gravity or weak extensors).

[Image of Erb's palsy waiter's tip deformity]

3. Klumpke’s Palsy: The "Claw Hand"

This injury affects the C8 and T1 roots, impacting the hand and wrist function while the shoulder often remains intact.

The Classic Deformity

• Claw Hand: Hyperextension of MCP joints and flexion of IP joints due to paralysis of intrinsic hand muscles (Lumbricals/Interossei).
• Forearm: Supinated (due to unopposed supinators, as pronators are weak).

⚠️ Clinical Pearl: Horner's Syndrome
If T1 is avulsed (torn from the spine), it may damage the sympathetic chain. Look for Horner's Syndrome on the affected side: 1. Ptosis (Drooping eyelid) 2. Miosis (Constricted pupil) 3. Anhidrosis (Lack of sweating)

4. Physiotherapy Management

Early intervention is vital to prevent contractures and encourage neural regeneration.

Phase 1: Protection (0-2 Weeks)

• Rest: Allow edema/hemorrhage to resolve.
• Positioning: Pin the sleeve to the shirt to prevent the arm from dangling. AVOID pulling the child by the arm.

Phase 2: Recovery & Stimulation

• PROM: Crucial to prevent contractures (especially shoulder adduction/IR contracture). Stabilize the scapula during movement.
• Sensory Stimulation: Rub different textures (silk, wool, brush) on the affected skin to map the brain.
• Active Movement: Use "tickling" or toys to elicit movement.
  • Erb's: Encourage Hand-to-Mouth (Cookie Test) movement.
  • Klumpke's: Encourage Grasping and finger opening.
• Weight Bearing: Propping on elbows (tummy time) to stimulate co-contraction.

Splinting

• Erb's: "Statue of Liberty" or Airplane splint (keeps shoulder abducted/externally rotated).
• Klumpke's: Cock-up splint or intrinsic-plus splint to prevent clawing.

5. Revision Notes

Erb's (C5-6): "Waiter's Tip". Top of plexus. Shoulder/Elbow affected. Hand is OK (usually). Most recover.
Klumpke's (C8-T1): "Claw Hand". Bottom of plexus. Hand affected. Shoulder is OK. Horner's Syndrome possible.
Total Plexus (C5-T1): Flaccid arm, no movement, sensory loss, poor prognosis.
Key Test: "Cookie Test" (child brings cookie to mouth) tests Biceps (C5-6).

6. FAQs

Q1. What is the "Cookie Test"?

It is a functional test for Biceps recovery in Erb's Palsy. You hand a child a cookie; if they flex the elbow to put it in their mouth without bending the neck down to meet the hand, they pass.

Q2. Do these injuries require surgery?

Most cases (approx 80-90%) recover spontaneously with therapy. However, if there is no bicep function by 3-6 months, nerve grafts or nerve transfers are considered.

Q3. What is the most common secondary complication?

Joint contractures (specifically shoulder internal rotation) and winging of the scapula. This leads to glenoid dysplasia (malformation of the shoulder socket).

7. 10 Practice MCQs

Q1. Erb's Palsy involves injury to which nerve roots?

Answer: B) The upper trunk of the brachial plexus.

Q2. The "Waiter's Tip" deformity consists of:

Answer: A) Caused by paralysis of deltoid, rotator cuff, and biceps.

Q3. Klumpke's Palsy is caused by:

Answer: B) This stretches the lower trunk (C8-T1).

Q4. Which reflex is typically absent in Erb's Palsy?

Answer: B) The Grasp reflex usually remains intact in Erb's because hand innervation (C8-T1) is spared.

Q5. Horner's Syndrome (ptosis, miosis, anhidrosis) is associated with:

Answer: B) Indicates avulsion of T1 root affecting the sympathetic chain.

Q6. In Klumpke's palsy, sensory loss is typically found over the:

Answer: C) Corresponding to the C8 and T1 dermatomes.

Q7. Which splint is commonly used for Erb's Palsy to prevent contracture?

Answer: A) It keeps the shoulder abducted and externally rotated.

Q8. Which muscle is NOT paralyzed in Erb's Palsy?

Answer: D) FCU is innervated by the Ulnar nerve (C8-T1), which is spared in Erb's.

Q9. The "Claw Hand" deformity in Klumpke's is due to weakness of:

Answer: B) Loss of intrinsics causes MCP hyperextension and IP flexion.

Q10. During the first 2 weeks (Acute phase) of a birth injury, the PT should:

Answer: B) Protect the healing nerve and prevent further traction injury.

References

• Tecklin, J. S. (2015). Pediatric Physical Therapy (5th ed.). Lippincott Williams & Wilkins.
• Pondaag, W., et al. (2011). Natural history of obstetric brachial plexus palsy: a systematic review. Dev Med Child Neurol.
• Campbell, S. K., et al. (2016). Physical Therapy for Children. Elsevier.