Erbs Palsy: Symptoms, Types, Causes and Treatment

Erb's palsy, also known as Erb-Duchenne palsy, is a form of brachial plexus injury that most often affects newborns during birth, but can also occur in adults. This condition can have a profound impact on arm and shoulder function, making early recognition and comprehensive management crucial for optimal outcomes. In this article, we'll explore the symptoms, types, causes, and treatment options for Erb's palsy, drawing on the latest research and clinical insights.

Symptoms of Erbs Palsy

When it comes to Erb’s palsy, understanding the early and ongoing symptoms is vital for timely intervention. The condition typically presents soon after birth, but the severity and range of symptoms can vary widely. Recognizing these signs not only helps parents and caregivers but also enables healthcare professionals to initiate prompt evaluation and care.

Main Symptom	Description	Affected Area	Evidence [Sources]
Weakness	Reduced muscle strength, especially upper arm	Shoulder, upper arm	1, 3
Limited Motion	Inability to move shoulder/arm as normal	Shoulder, elbow	1, 3
Waiter's Tip	Characteristic arm position (adduction, internal rotation, extended elbow, pronated forearm)	Arm	13, 3
Decreased Reflexes	Reduced Moro or biceps reflex on affected side	Arm	3

Table 1: Key Symptoms

Common Clinical Features

The hallmark symptoms of Erb's palsy include weakness and partial or complete loss of movement in the affected arm, most often the upper and middle sections. Newborns may hold their arm limply at their side, with the elbow extended and the forearm pronated—a position referred to as the "waiter's tip" 13 3.

• Muscle Weakness: Most prominent in the shoulder and upper arm muscles, especially those innervated by the C5 and C6 nerve roots. Babies may struggle to flex the elbow or lift their arm away from the body 1 3.
• Decreased Reflexes: The Moro reflex (startle response) and the biceps reflex may be diminished or absent in the affected arm 3.
• Limited Range of Motion: Children may have difficulty performing simple actions, such as bringing the hand to the mouth or reaching overhead.
• No Grip Impairment: Unlike more extensive brachial plexus injuries, the hand’s grip strength is usually preserved in isolated Erb’s palsy 1.
• Muscle Atrophy and Growth Disparity: Over time, the affected arm may be smaller or shorter due to disuse and impaired muscle development 13.

Progression and Complications

Without timely intervention, chronic Erb's palsy can lead to secondary complications:

• Joint Contractures: Stiffness in the elbow or shoulder due to imbalanced muscle activity 3.
• Shoulder or Elbow Dislocation: Weak muscles may allow for abnormal joint positioning 3.
• Functional Impairment: Long-term difficulty in performing daily activities if muscle strength and joint mobility are not restored.

Types of Erbs Palsy

Erb's palsy is not a one-size-fits-all diagnosis—there are several subtypes and classifications, each with unique clinical implications. By understanding these categories, clinicians can better tailor treatment and predict outcomes.

Type	Nerves Involved	Severity Level	Evidence [Sources]
Upper Erb’s	C5, C6	Mild to moderate	2, 3
Extended Erb’s	C5, C6, C7	Moderate to severe	2, 3
Total Palsy	C5-T1	Severe (whole arm)	3, 2
With Horner’s	C5-T1 plus sympathetic	Most severe (includes ptosis, miosis)	2

Table 2: Types of Erb’s Palsy

The Narakas Classification

One of the most widely used systems for categorizing Erb's palsy is the Narakas classification 2, which divides cases based on the extent of nerve involvement:

• Group I (Upper Erb’s): Injury to C5 and C6 (sometimes partial C7). Presents with classic “waiter’s tip” and sparing of hand function.
• Group II (Extended Erb’s): Involves C5, C6, and C7. Greater weakness, including wrist and finger extension.
• Group III (Total Palsy): All five roots (C5-T1) are affected. Complete paralysis of the arm and hand.
• Group IV (Total Palsy with Horner’s): Total palsy plus symptoms like ptosis and miosis from sympathetic nerve involvement.

Prognosis and Subtypes

• Extended Erb’s Subclassification: Recent studies show that infants with extended Erb's palsy who regain active wrist extension against gravity within the first two months have a much higher chance of good spontaneous recovery 2. This finding allows for further subclassification and helps guide early intervention.
• Other Variants: While Erb's palsy most often refers to obstetric (birth-related) injury, similar syndromes can occur in adults due to trauma or repetitive motion (e.g., "military brace syndrome") 8.

Distinction from Other Plexus Injuries

• Klumpke’s Palsy: Unlike Erb’s, Klumpke’s palsy affects the lower plexus (C8-T1), resulting in hand weakness and “claw hand” deformity 3.
• Mixed Types: Some cases involve both upper and lower trunks, resulting in mixed symptom patterns and more complex treatment needs 3.

Causes of Erbs Palsy

Understanding the causes of Erb’s palsy helps dispel myths and ensures that parents and caregivers receive accurate information. While birth injury is the most common cause, research reveals a more nuanced picture of how and why this condition develops.

Cause	Key Factors	Typical Scenario	Evidence [Sources]
Maternal Forces	Uterine contractions, pushing	Vaginal delivery	5, 6, 7
Shoulder Dystocia	Baby’s shoulder gets stuck during birth	Difficult labor	4, 5, 6
Instrumental Delivery	Use of forceps or vacuum	Assisted delivery	4
High Birth Weight	Larger babies at greater risk	Macrosomia	4
Non-Obstetric Trauma	Repetitive motion, trauma (e.g., military brace)	Postnatal/adult	8

Table 3: Causes of Erb’s Palsy

Birth-Related Causes

• Uterine and Maternal Forces: Strong contractions and maternal pushing can stretch the baby’s brachial plexus during passage through the birth canal. Contrary to longstanding belief, current evidence suggests these natural forces, rather than clinician-applied traction, are often responsible for most cases 5 6 7.
• Shoulder Dystocia: This occurs when the baby's shoulder becomes lodged behind the mother's pubic bone. While associated with Erb’s palsy, only about half of cases involve documented shoulder dystocia 5 6. Erb’s palsy can occur even when no dystocia is observed.
• Instrumental Delivery: Use of forceps or vacuum extractors increases risk, particularly in larger babies. However, cesarean section offers some protection 4.
• High Birth Weight (Macrosomia): Infants weighing over 4,000g (8.8 lbs) have a significantly higher risk, especially with instrumental or midpelvic vaginal deliveries 4.

Non-Obstetric and Adult Causes

• Repetitive Motion or Trauma: Erb’s palsy can develop in adults due to trauma, sports injuries, or activities causing nerve entrapment. For example, the "military brace" posture in cadets has been linked to similar nerve injuries 8.
• Congenital vs. Acquired: While most cases are congenital (present at birth), some may result from accidents, tumors, or inflammation affecting the brachial plexus.

Debunking Myths

• Not Always Due to Medical Error: Despite historic claims, research shows that birth attendant actions are not the primary cause in most cases. Instead, the combination of maternal, fetal, and mechanical factors plays the dominant role 5 7.
• Occurrence Without Shoulder Dystocia: Studies have confirmed that Erb's palsy can arise without any observable shoulder dystocia, reinforcing the complexity of causation 6.

Treatment of Erbs Palsy

Timely and tailored treatment is crucial for maximizing recovery in children with Erb’s palsy. Management ranges from conservative methods like physiotherapy to complex surgical interventions for persistent or severe cases.

Treatment Modality	Key Features	Typical Outcome	Evidence [Sources]
Physiotherapy	Range-of-motion, strengthening exercises	Improved mobility	13, 3
Nerve Surgery	Grafting, transfers, neurolysis	Functional restoration	10, 12, 9
Conservative Management	Observation, splinting, therapy	Many recover spontaneously	3, 2
Alternative Therapies	Ayurvedic massage, electrical stimulation	Adjunctive improvement	13

Table 4: Treatment Approaches

Conservative Management

• Observation: Many cases, especially mild upper Erb’s palsy, improve without surgery. Spontaneous recovery often begins within 2–3 months if wrist extension returns early 2 3.
• Physiotherapy: Early and regular therapy is essential. Exercises focus on maintaining joint flexibility and preventing contractures 13 3.
• Splinting: Used to support the affected arm and prevent abnormal positioning.

Surgical Interventions

• Nerve Grafting: For infants not showing sufficient recovery by 3–6 months, surgical intervention may be recommended. Resection of damaged nerve segments and interpositional nerve grafting has been shown to significantly improve long-term function 10 12.
• Nerve Transfers: Extraplexal and intraplexal nerve transfers are advanced surgical options when the original nerve root is not available for repair 12.
• Neurolysis: Once a mainstay, neurolysis (freeing nerves from scar tissue) alone does not provide sustained improvement and is no longer favored as a standalone procedure 10 9.

Adjunct and Alternative Therapies

• Ayurvedic and Integrative Approaches: Some centers incorporate Ayurvedic oil massage, nourishing treatments, and electrical stimulation to enhance muscle function and growth. While not widely adopted, these methods have shown anecdotal benefits as adjuncts to standard therapy 13.
• Secondary Reconstruction: In older children with persistent deficits, tendon transfers or osteotomies may be considered to improve specific movements 3.

Prognosis and Long-term Outcomes

• Early Recovery Predicts Success: Children who regain specific movements (like wrist extension) within two months are most likely to have good functional outcomes 2.
• Importance of Early Intervention: Delays in therapy or surgery can result in permanent weakness, joint stiffness, or limb length discrepancies 13 3.
• Holistic Rehabilitation: Multidisciplinary care, including physiatrists, surgeons, therapists, and families, is crucial for optimal recovery.

Conclusion

Erb's palsy is a complex condition that arises primarily from birth-related trauma to the brachial plexus, but can also be seen in non-obstetric settings. Early identification, accurate classification, and a holistic, evidence-based approach to management are the keys to maximizing functional outcomes.

Main Takeaways:

• Symptoms include upper arm weakness, limited motion, and the classic "waiter's tip" position; most cases spare hand grip.
• Types are classified by nerve involvement, ranging from upper Erb’s (C5-C6) to total palsy with Horner’s syndrome.
• Causes are multifactorial, with maternal forces, shoulder dystocia, instrumental delivery, and high birth weight as major risk factors; not always due to clinician error.
• Treatment should start early, with conservative therapy for mild cases and surgical intervention for persistent or severe deficits; a multidisciplinary approach yields the best outcomes.

By empowering families and clinicians with up-to-date knowledge, we can improve the lives of those affected by Erb’s palsy—maximizing every child’s potential for movement, growth, and independence.