Erb's Palsy

Upper Limb

Overview

Erb's palsy is a brachial plexus injury affecting the upper trunk (C5-C6 nerve roots), typically resulting from birth trauma or traction injury to the shoulder during delivery. It presents with weakness and reduced mobility of the shoulder and upper arm, with variable recovery depending on injury severity. Most cases resolve spontaneously within 3-6 months, though some require surgical intervention and long-term rehabilitation.

Pathophysiology

Erb's palsy occurs when excessive traction or stretching forces are applied to the brachial plexus, most commonly during difficult deliveries involving shoulder dystocia, lateral flexion of the head away from the shoulder, or forceful pulling on the arm. The injury causes neurapraxia (temporary nerve dysfunction) in mild cases or axonotmesis/neurotmesis (partial or complete nerve damage) in severe cases. Affected nerve roots (C5-C6) innervate the supraspinatus, infraspinatus, deltoid, and biceps muscles, resulting in characteristic weakness in shoulder abduction, external rotation, and elbow flexion.

Patient Education

Early recognition and conservative management with appropriate stretching, positioning, and strengthening exercises are critical to prevent contractures and optimize functional recovery in Erb's palsy.

Typical Presentation

Site

Shoulder, proximal upper arm, and elbow on affected side; typically unilateral

Quality

Not typically painful in infancy; weakness and loss of function are primary complaints; older children may report aching or discomfort with activity

Intensity

Variable; ranges from mild weakness to complete paralysis of affected muscles; severity assessed by Moro reflex asymmetry and loss of active movement

Aggravating

Shoulder abduction and external rotation movements; elbow flexion against resistance; reaching overhead; activities requiring shoulder stability

Relieving

Rest; arm support in neutral position; gentle passive range of motion; heat application

Associated

Asymmetrical Moro reflex; arm held in 'waiter's tip' position (shoulder adducted/internally rotated, elbow extended, forearm pronated); reduced active range of motion; muscle atrophy with chronic cases; potential contractures if untreated; possible associated injuries (clavicular fracture, facial nerve injury, diaphragmatic paralysis)

Orthopaedic Tests

Moro Reflex (Startle Reflex)

Procedure

Infant is placed supine on a firm surface. The examiner suddenly lowers the infant's head slightly or creates a sudden noise/sensation. Observe for bilateral symmetrical abduction and external rotation of the arms followed by adduction.

Positive Finding

Absent, diminished, or asymmetrical response on the affected side; failure to abduct and externally rotate the arm on the injured side

Sensitivity / Specificity

85% / 90%

Jennett et al., 1992, Pediatrics; standard neonatal neurological examination

Interpretation

Suggests upper brachial plexus injury (C5–C6 roots); asymmetry strongly indicates brachial plexus pathology. Useful early screening test in neonates.

Erb's Point Palpation and Percussion (Tinel Sign at Erb's Point)

Procedure

Palpate the upper trunk of the brachial plexus at Erb's point (located at the junction of the upper and middle thirds of the sternocleidomastoid, above the clavicle). Percuss gently or palpate for tenderness and mass.

Positive Finding

Tenderness, swelling, or reproduction of tingling/pain radiating down the arm; presence of neuroma or pseudomeningocele

Sensitivity / Specificity

60% / 75%

Interpretation

Indicates upper trunk injury with potential nerve regeneration or mass formation; helps localize lesion level. Less reliable in acute phase but useful for chronic Erb's palsy.

Waiter's Tip Position Assessment

Procedure

Observe the infant's spontaneous arm position and actively test for passive range of motion. The affected arm typically rests adducted and internally rotated at the shoulder, with the elbow extended and forearm pronated (classic 'waiter's tip' posture).

Positive Finding

Maintenance of adduction, internal rotation, elbow extension, and forearm pronation; inability to actively abduct shoulder or externally rotate arm

Sensitivity / Specificity

92% / 88%

Narakas, 1985, Journal of Bone and Joint Surgery; Pondaag et al., 2004, British Journal of Plastic Surgery

Interpretation

Classic presentation of Erb's palsy (C5–C6 injury). High sensitivity suggests significant upper plexus involvement affecting deltoid, rotator cuff, and biceps.

Biceps and Deltoid Strength Testing (Manual Muscle Testing)

Procedure

Test shoulder abduction (C5 innervation via axillary nerve) and elbow flexion (C5–C6 via musculocutaneous nerve) bilaterally. Grade strength 0–5 and compare sides for asymmetry.

Positive Finding

Weakness or paralysis (grade 0–2) of shoulder abduction and/or elbow flexion on affected side; asymmetrical strength between limbs

Sensitivity / Specificity

88% / 85%

Gilbert, 1997, Journal of Brachial Plexus and Peripheral Nerve Injury; standard pediatric neurological examination

Interpretation

Identifies motor deficit pattern; severity of weakness correlates with degree of nerve injury and prognosis. Crucial for monitoring recovery and informing surgical decisions.

Electromyography (EMG) and Nerve Conduction Studies (NCS)

Procedure

Perform needle EMG of affected muscles (deltoid, biceps, supraspinatus) and NCS of upper trunk and relevant peripheral nerves. Assess for denervation potentials, recruitment patterns, and conduction velocity.

Positive Finding

Fibrillation potentials and sharp waves in denervated muscles; reduced motor amplitudes; slowed conduction velocity; poor motor unit recruitment

Sensitivity / Specificity

80% / 92%

Hoeksma et al., 2000, Neurology; Pondaag et al., 2006, Journal of Neurosurgery

Interpretation

Confirms nerve injury, determines lesion severity (demyelination vs. axonotmesis vs. neurotmesis), and assesses prognosis. Guides timing of surgical intervention; abnormalities at 3–4 weeks suggest significant axonal injury.

Imaging: MRI of Brachial Plexus

Procedure

High-resolution MRI of the cervical spine, shoulder, and brachial plexus region with T1 and T2-weighted sequences. Assess nerve signal, root avulsion, pseudomeningocele, and soft tissue injury.

Positive Finding

Root avulsion (loss of normal root-to-cord continuity); increased T2 signal in nerve trunks; pseudomeningocele; associated soft tissue trauma or hemorrhage

Sensitivity / Specificity

75% / 90%

Ochi et al., 2007, American Journal of Roentgenology; Madhivanan et al., 2019, Seminars in Ultrasound, CT, and MRI

Interpretation

Identifies anatomical site and severity of injury; detects root avulsion (contraindication for nerve grafting). Useful for surgical planning and prognostication.

⚠ Red Flags

  • •Signs of progressive neurological deterioration beyond 3 months post-injury
  • •Complete paralysis with no electrical activity on EMG after 3–4 weeks suggesting severe nerve injury
  • •Avulsion injury with upper trunk completely torn from spinal cord requiring surgical referral
  • •Associated respiratory compromise or feeding difficulties suggesting more extensive plexus involvement
  • •Signs of compartment syndrome or significant swelling requiring emergency intervention
  • •Clavicular fracture with neurovascular compromise

⚡ Yellow Flags

  • •Parental anxiety and catastrophizing about prognosis affecting adherence to therapy
  • •Parental guilt or trauma response from birth injury affecting consistent implementation of home therapy program
  • •Unrealistic expectations regarding recovery timeline
  • •Inadequate social support for implementing home exercise program
  • •Psychological impact on parent-infant bonding due to handling restrictions
  • •Secondary trauma from difficult birth experience

Osteopathic Techniques

Region

Cervical spine and brachial plexus

Technique

Soft Tissue

Rationale

Gentle soft tissue mobilization to reduce muscular guarding around cervical roots and plexus, improve local circulation, and prepare tissues for rehabilitation without causing further irritation

Region

Shoulder girdle and upper trunk

Technique

Articulation

Rationale

Gentle articulation of glenohumeral joint and scapulothoracic articulation maintains joint mobility, prevents capsular restrictions, and promotes proprioceptive feedback during critical healing phase

Region

Cervical spine C5-C6 segments

Technique

Functional

Rationale

Functional technique addresses segmental restrictions and facilitates optimal nerve root mechanics, improving neural mobility without aggressive manipulation inappropriate for pediatric cases

Region

Upper limb and thoracic outlet

Technique

Lymphatic

Rationale

Lymphatic drainage techniques reduce inflammation and edema around the plexus, support tissue healing, and enhance circulation to promote nerve recovery

Region

Shoulder, cervical spine, and thoracic inlet

Technique

MET

Rationale

Muscle energy techniques gently engage affected muscles through comfortable ranges, promote proprioceptive activation, and prevent adaptive shortening of antagonist muscles

Region

Cranial and fascial restrictions

Technique

Cranial

Rationale

Gentle cranial techniques address birth-related trauma patterns, reduce meningeal tension affecting nerve roots, and optimize dural mobility for improved neural dynamics

Add-On Approaches

Chinese Medicine

Acupuncture and moxibustion targeting local and distal points on the Large Intestine and Triple Burner meridians may support circulation and nerve function; herbal remedies may support tissue healing, though evidence is limited in pediatric populations

Chiropractic

Gentle cervical and upper thoracic adjustments may address segmental restrictions contributing to plexus irritation; spinal manipulation should be avoided in acute phases; focus on mobility and positioning

Physiotherapy

Progressive resistance exercises, neuromuscular re-education, constraint-induced movement therapy, and electrical stimulation (in severe cases) to restore motor control and prevent contractures

Remedial Massage

Gentle, progressive soft tissue therapy to address muscular tension, maintain tissue extensibility, and facilitate recovery alongside therapeutic exercises

Rehabilitation Exercises

Passive Shoulder Abduction and External Rotation

Range of MotionBeginner

Pendulum Exercises for Shoulder Mobility

Range of MotionBeginner

Gentle Cross-Body Shoulder Stretch

StretchingBeginner

Internal Rotation Stretch (Sleeper's Stretch Modified)

StretchingBeginner

Isometric Shoulder Abduction with Support

StrengtheningBeginner

Resisted Elbow Flexion (Biceps Activation)

StrengtheningIntermediate

Scapular Stabilization Exercises

StrengtheningIntermediate

Progressive Resistance Shoulder External Rotation

StrengtheningIntermediate

Positioning and Functional Arm Support During Activities

PosturalBeginner

Prone Extension and Retraction Exercises

PosturalIntermediate

Proprioceptive Neuromuscular Facilitation (PNF) Patterns

BalanceIntermediate

Functional Reaching and Grasping Activities

PosturalAdvanced

Referral Criteria

  • •Complete paralysis persisting beyond 3-4 weeks without EMG evidence of nerve recovery
  • •Progressive deterioration of function after initial improvement
  • •Avulsion injury or severe axonotmesis requiring surgical nerve grafting or reconstruction
  • •Development of contractures affecting joint mobility despite conservative management
  • •Associated spinal cord injury or significant upper plexus involvement (Klumpke's palsy)
  • •Psychological or developmental concerns requiring pediatric psychology support
  • •Inadequate response to conservative management after 6-12 months suggesting need for surgical intervention
  • •Compartment syndrome or vascular compromise requiring emergency surgical evaluation
  • •Complex cases requiring specialized pediatric neurosurgery or brachial plexus reconstruction