Erb's Palsy
Upper LimbOverview
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
Test descriptions are written with AI assistance from standard clinical texts. Where a test lists Sources, its description has been checked against them; those sources are independent and do not endorse OsteoKit. Accuracy figures and grades (A–D) appear only when checked against the published study; tests without one are marked “No accuracy study”.
Further reading: full test procedures are described in standard clinical examination texts, e.g. Magee & Manske, Orthopedic Physical Assessment (7th ed.), and Cook & Hegedus, Orthopedic Physical Examination Tests: An Evidence-Based Approach (2nd ed.).
Moro Reflex (Startle Reflex)
Procedure
Infant supine on a firm surface, head supported in your hand. Let the head drop a short distance (a few centimetres) into your hand, keeping it supported, and watch both arms.
Positive Finding
Asymmetrical response: the affected arm does not abduct and extend like the other arm.
Interpretation
An asymmetrical Moro reflex in a newborn supports a brachial plexus birth injury, most often of the upper roots (C5–C6). It can also be asymmetrical with a clavicle or humerus fracture, which causes pain-related loss of movement (pseudoparalysis), so examine and refer for medical assessment.
Sources
Erb's Point Palpation and Percussion (Tinel Sign at Erb's Point)
Procedure
Palpate gently above the clavicle, just behind the sternocleidomastoid (Erb's point), then tap lightly over it. In older children and adults, ask what is felt; in infants, watch the response.
Positive Finding
Tingling spreading into the arm (in patients able to report it), or a tender swelling suggesting a neuroma.
Interpretation
Tingling on tapping suggests irritation or regrowth of the upper trunk at that point, which helps locate the lesion and can be followed over time. It is not a diagnostic test for Erb's palsy.
Waiter's Tip Position Assessment
Procedure
Observe the resting position of the arm and the spontaneous movements, then compare both sides.
Positive Finding
The arm hangs adducted and internally rotated at the shoulder, with the elbow extended, forearm pronated and wrist flexed.
Interpretation
This is the classic posture of an upper plexus (C5–C6) injury, caused by weakness of the shoulder abductors, external rotators and elbow flexors. It describes the pattern; it is not a separate test. Check for fracture and refer for medical and specialist assessment.
Biceps and Deltoid Strength Testing (Manual Muscle Testing)
Procedure
In infants, observe active movement (shoulder abduction and elbow flexion) against gravity and with gravity eliminated, and record it on a recognised scale such as the Active Movement Scale. In older children and adults, grade strength by manual muscle testing and compare both sides.
Positive Finding
Weak or absent shoulder abduction and elbow flexion on the affected side.
Interpretation
Weak deltoid and biceps fit an upper trunk (C5–C6) lesion. Recovery of elbow flexion over the first months is an important sign used by specialists when deciding on nerve surgery, so serial recording is valuable.
Electromyography (EMG) and Nerve Conduction Studies (NCS)
Procedure
Performed by a specialist. Nerve conduction studies and needle EMG of the affected muscles, often repeated over time.
Positive Finding
Signs of denervation in muscles supplied by the injured roots, reduced responses, or evidence of ongoing re-innervation.
Interpretation
Helps show the severity of the nerve injury and whether it is recovering, which guides the timing of surgery. Results can be difficult to interpret in infants and are used with the clinical examination.
Imaging: MRI of Brachial Plexus
Procedure
Arranged by the specialist: MRI (or CT myelography) of the cervical spine and brachial plexus.
Positive Finding
Root avulsion from the spinal cord, a pseudomeningocele, or signal change in the plexus.
Interpretation
Shows the site and type of injury, especially root avulsion, which cannot recover on its own and changes surgical planning.
Sources
⚠ 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
Refer first
This condition needs medical assessment and management first. Do not use neck-directed manual techniques. Any osteopathic care is supportive, away from the injured area, and only once the treating team has cleared it. Most infants are managed with early physiotherapy and occupational therapy, with families taught passive stretching. Incomplete recovery by 1 month needs specialist referral.
- Journal articleRushton et al. · J Orthop Sports Phys Ther 2023
- Reference bookStenersen & Bordoni · StatPearls 2024
- Reference bookBazzi & Sergent · StatPearls 2023
- Reference bookBisht et al. · StatPearls 2026
Rehabilitation Exercises
Passive Shoulder Abduction and External Rotation
Pendulum Exercises for Shoulder Mobility
Gentle Cross-Body Shoulder Stretch
Internal Rotation Stretch (Sleeper's Stretch Modified)
Isometric Shoulder Abduction with Support
Resisted Elbow Flexion (Biceps Activation)
Scapular Stabilization Exercises
Progressive Resistance Shoulder External Rotation
Positioning and Functional Arm Support During Activities
Prone Extension and Retraction Exercises
Proprioceptive Neuromuscular Facilitation (PNF) Patterns
Functional Reaching and Grasping Activities
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