Erb's Palsy
Erb's palsy is a birth injury that affects the nerves controlling arm and hand movement. When these nerves are stretched or damaged during childbirth, it can lead to weakness or even paralysis in the arm. Learn about what causes Erb's palsy and how parents can care for their child with this condition.
What Is Erb's Palsy?
Erb's palsy, also known as Erb-Duchenne palsy, is a type of brachial plexus injury that results in weakness or paralysis of the shoulder and arm. It is typically caused by nerve damage during childbirth and affects 1-2 infants per 1,000 births, making it one of the most common neurological birth injuries.
In most cases, Erb's palsy only affects the arm and shoulder on one side of the body. Depending on the level of nerve damage, many children may recover with help from physical and occupational therapy in milder cases, while others with more severe injuries may require surgery and more intensive therapy.
What Causes Erb's Palsy?
The main cause of Erb's palsy is trauma to the brachial plexus during childbirth, particularly when excessive stretching occurs between the baby's neck and shoulders.
There are a number of different ways Erb's palsy can occur, some of them avoidable, while others are the result of medical mistakes made during delivery. Learn about the common causes of Erb's palsy below.
Shoulder Dystocia
Shoulder dystocia occurs during a difficult vaginal delivery when a baby's shoulder becomes lodged behind the mother's pelvic bone. When the shoulder gets stuck in the birth canal, the delivery team will need to carefully maneuver the baby's limbs to free their shoulder.
In some cases, excessive downward force on the baby's head or neck can stretch or tear the brachial plexus nerves. The most common errors made that cause shoulder dystocia are:
- Applying too much traction to the baby's head or neck
- Failing to follow standard shoulder release maneuvers
- Not calling for extra assistance or help
- Failing to recognize signs the shoulder is stuck before damage is caused
When shoulder dystocia is not managed correctly, medical negligence can also lead to Erb's palsy and other brachial plexus injuries.
Improper Use of Delivery Tools
Assisted delivery tools such as forceps and vacuum extractors are commonly used to deliver babies through the birth canal. If too much force or pressure is applied, this can cause damage to the baby's upper body and cause Erb's palsy.
Common errors made with delivery tools:
- Pulling too forcefully or quickly while the shoulder is stuck
- Improper angle of traction causing the neck to stretch
- Rotating the head during a shoulder dystocia
- Applying pressure that compresses or stretches the neck region
- Delivering the head without ensuring shoulder release
Abnormal Fetal Presentation and Positioning
Certain baby positions create a higher risk for brachial plexus stretching. The most common positions that can increase the risk of Erb's palsy are:
- Breech Position: When the baby is breech, the arms are shoulders may be stuck above their head. Pulling to extract the baby's body or arms can injure the nerves.
- Face, Brow, or Transverse Presentation: Malposition can increase the likelihood of difficult extraction, prolonged pushing, or increased force needed to rotate or deliver the baby.
Prolonged or Obstructed Labor (Labor Dystocia)
When a baby remains in the birth canal too long or cannot descend, physical pressure and forceful interventions by medical providers become more likely.
If labor does not progress normally, risks such as repeated traction attempts, neck compression during tight fits, and pressure from the birth canal can create nerve strain before birth is complete. Medical staff must quickly recognize labor that is not progressing and take steps to prevent emergencies that lead to rushed pulling.
Large Babies (Fetal Macrosomia)
Babies weighing more than 8 lbs 13 oz (4000 g) or with larger-than-expected shoulder width have higher risks of shoulder impaction during delivery. Macrosomia can be linked to medical errors that may lead to Erb's palsy including:
- Not screening for maternal diabetes
- Ignoring ultrasound findings of large fetal size
- Attempting vaginal delivery when C-section is safer
- Applying excessive traction when the shoulders stick
Note: Macrosomia itself does not cause Erb's palsy. The provider's response to difficult delivery is what often results in nerve injury.
Failure to Properly Monitor Maternal Risk Factors
When providers fail to properly monitor maternal risk factors, the likelihood of shoulder dystocia or other complications leading to Erb's palsy increases. Common high-risk maternal factors include:
- Gestational diabetes
- Excessive maternal weight gain
- Short stature or small pelvic anatomy
- Prior shoulder dystocia
- Prolonged second stage of labor
- Induction complications
If doctors and medical staff wait too long before intervention, such as delaying a C-section, preventable nerve damage can occur, leading to Erb's palsy.
How Is Erb's Palsy Diagnosed?
Erb's palsy is diagnosed shortly after birth, often while the baby is still in the hospital. Doctors and nurses may first notice one arm hangs limply or doesn't move as much as the other.
If you notice signs of Erb's palsy in your child later on, your pediatrician will re-examine your child and may refer you to a pediatric neurologist or brachial plexus specialist who can diagnose your child.
Some tests they may use include:
Physical Examination
A thorough physical examination is likely the first test specialists will use to diagnose your child. They will test and analyze:
- Arm posture: Doctors look for the "waiter's tip" position - arm hanging at the side, shoulder turned inward, elbow straight, and forearm pronated.
- Range of motion: They gently move the shoulder, elbow, and wrist to see how much movement is possible and if there is any stiffness or pain.
- Strength testing (as much as the baby allows): They watch for active shoulder lifting, elbow bending, and hand grasping compared with the other side.
- Reflexes: The Moro (startle) reflex is tested to see if it is absent on the affected side.
- Sensation: They may gently touch or stroke different parts of the child's arm to check for responses like withdrawal, facial reactions, or crying.
If the patterns of weakness match the upper brachial plexus (C5-C6, sometimes C7), this is usually a sign of Erb's palsy.
Medical Diagnostic Tests
If your child's arm weakness doesn't improve over the first 6 to 12 weeks, or the injury seems severe from the beginning, specialists may order tests to look directly at the nerve and muscle function, such as:
- Electromyography (EMG): Tiny needles are placed in specific muscles to measure their electrical activity. EMGs can show whether the muscle is getting signals from the nerve and whether there is ongoing denervation (nerve damage).
- Nerve conduction studies (NCS): Small electrical impulses are sent along the nerve to see how quickly and effectively signals travel. Slowed or absent conduction suggests a potentially more serious nerve injury.
- MRI of the brachial plexus and cervical spine: To look for nerve root avulsions (nerve ripped from spinal cord), scar tissue, or pseudomeningoceles (cerebrospinal fluid-filled sacs that suggest root injury).
- CT myelography: A dye study of the spinal canal that can highlight nerve root damage and create visual images of the affected area (used less often in infants due to invasiveness).
Your child's doctor will likely use a combination of these tests to properly diagnose your child's condition. The sooner your child is diagnosed, the sooner they can start treatment and therapy to improve their recovery.
What Are the Symptoms of Erb's Palsy?
Symptoms of Erb's palsy depend on the severity of nerve damage. Unlike cerebral palsy, which can cause muscle stiffness and mobility issues in multiple areas of the body, Erb's palsy mainly affects the arm and shoulder on one side of the body.
Some children may have some weakness in milder cases and total paralysis in more severe cases. Some common symptoms of Erb's palsy include:
Physical Symptoms
- Limited or no movement in the affected arm
- Arm hangs limp with internal rotation ("waiter's tip" position)
- Reduced grip strength
- Absent Moro reflex on affected side
- Muscle weakness in the shoulder, biceps, or forearm
Pain or Sensory Symptoms
Even though infants cannot verbalize pain, nerve injury symptoms may appear as:
- Increased fussiness when their arm is moved
- Sensitivity to touch
- Altered muscle tone (floppy or stiff limb)
As children grow older, they might describe the arm as:
- Sensations described as "tingly", "numb", or "asleep"
- Feeling achy or sore after activity or at the end of the day
- Sensitive when touched, stretching, or certain positions
Long-Term Symptoms
If untreated, long-term complications of Erb's palsy may include:
- Contractures: Muscles and soft tissues around the shoulder, elbow, or arm tighten over time, making the joint hard to move.
- Muscle atrophy: Shrinking or weakening muscles from lack of use.
- Abnormal limb growth: The affected arm may look shorter or smaller. Asymmetry can also affect posture, balance, and how clothing or adaptive equipment fits.
- Reduced range of motion: Limited range of motion makes it harder to participate in sports, playground activities, and daily tasks.
- Shoulder instability: Pain, clicking, or a feeling that the shoulder isn't "secure" during movement.
- Joint deformity: Chronic muscle imbalance and abnormal forces on the joint can gradually change the shape of the shoulder socket or upper arm bone, potentially requiring surgery to correct.
- Chronic pain or discomfort: Aching, fatigue, or sharp pain around the shoulder and neck after activity. Pain can interfere with sleep, school, work, and participation in sports or daily life.
- Paralysis: Possible partial or complete loss of ability to move the shoulder or arm.
- Emotional and social impacts: Visible differences in arm size or movement can affect self-esteem. Children may feel self-conscious of how they look in photos or during activities.
What Are the Types of Erb's Palsy?
Doctors classify Erb's palsy in two main ways:
- The type of nerve damage, and
- Which nerve roots are affected
Neurapraxia
Neurapraxia is the most common type of brachial plexus injury and is usually the mildest type. This happens when the nerve is stretched but not torn. Many babies with neurapraxia gradually regain strength and movement over weeks to months as the nerve recovers.
Neuroma
Neuroma occurs when the nerve tears and then heals, forming scar tissue around it. The scar tissue compresses the nerve, which can limit recovery. Children with neuroma may improve but often have persistent weakness or limited motion that can sometimes be corrected with surgery.
Rupture
Ruptures happen when the nerve is completely torn but not pulled away from the spine. Because the nerve ends are separated, the body cannot repair the connection on its own and often requires surgery to restore nerve signals to the arm.
Avulsions
Avulsions are the most severe type of brachial plexus injury and can even lead to permanent paralysis in the arm. This occurs when the nerve is ripped away from the spinal cord at its root.
Avulsed nerves cannot be reattached directly to the spinal cord and require nerve transfers to restore some function. Children with avulsions are more likely to have significant, lifelong weakness or paralysis in the affected area, even with surgery and therapy.
How Is Erb's Palsy Treated?
Depending on the severity of brachial plexus injury, treatment for Erb's palsy may vary. Most children with mild Erb's palsy recover with light physical and occupational therapy. In more severe cases, surgery may be considered if the child is not showing any signs of improvement after 3-6 months.
Physical Therapy
Physical therapy helps children with Erb's palsy reduce stiffness, increase strength, and improve mobility in their affected shoulder or arm. Some routines physical therapists may incorporate, even within the first few weeks of the baby's life are:
- Stretching the shoulder to prevent contractures
- Strengthening elbow flexion to improve range of motion
- Encouraging symmetrical movement and alignment
- Promoting sensory stimulation with touch response exercises
Occupational Therapy
If a child's condition doesn't improve on its own after a few months, occupational therapy can help them build strength and coordination during daily activities or tasks such as feeding or getting dressed.
Occupational therapists can help children:
- Improve fine motor skills and functions like using a zipper or buttoning a shirt
- Develop grip strength for holding toys or devices
- Use the affected arm in feeding and play
Surgery
In more severe cases of Erb's palsy, surgery may be recommended if there is little to no improvement by 3-6 months. The most common surgery for Erb's palsy includes:
- Nerve Graft: Repairs damaged nerves by replacing the damaged or severed nerves with a healthy sensory nerve from another part of the body (often the sural nerve in the leg). This grafted nerve acts as a bridge to reconnect the damaged brachial plexus and restores function.
- Nerve Transfer: Takes a functioning nerve from a non-critical muscle in the body and reroutes it to activate a more important muscle that lost innervation.
- Muscle Transfer: This procedure moves healthy muscles from a non-affected area of the body to the damaged area to improve strength and function in the shoulder or arm.
- Tendon Transfer: Involves moving healthy tendons from one part of the body to the affected shoulder or arm to restore range of motion and strength.
- Tendon Release: Cutting a tight or shortened tendon that is causing stiffness or limited range of motion to free the shoulder or elbow.
The timing of nerve surgery really matters. According to an NIH study, nerve reconstruction performed within the first 3 to 6 months of life yields better shoulder function and requires fewer operations than surgery done later. This is mostly because regenerating nerves have a favorable "window" for growth when the child is younger.
Quick Fact: Families who are considering surgery for their child should keep in mind that nerve transfers can potentially take months or even years to show progress because nerves regrow slowly. Physical and occupational therapy also promote faster recovery and help children to regain strength and movement, and prevent contractures after their operation.
Can My Child Recover from Erb's Palsy?
Even though Erb's palsy has a wide range of possible outcomes, from almost full recovery to lasting weakness, joint changes, or visible arm differences, 80-90% of children diagnosed with Erb's palsy will make a full recovery.
Prognosis depends on the severity of the nerve damage, how quickly treatment begins, and how consistently therapy and follow-up care are followed. Below is a recovery timeline for most children diagnosed with Erb's palsy.
Typical Prognosis and Recovery Timelines for Erb's Palsy
First 3 Months: Many babies with mild injuries (neurapraxia) start to show returning movement in their shoulder and elbow. Doctors will closely watch for signs like active elbow flexion (bending) and shoulder movement. If improvements aren't seen by around 3 months, surgery will often be considered.
3—6 Months: Children with moderate injuries may continue to gain strength and movement with physical therapy. Prognosis is generally better when they regain elbow flexion and external rotation of their shoulder.
6—12 Months: For more severe injuries (neuroma or avulsions), nerve surgery (like grafting or transfers) may be performed in early infancy. Functional improvements from surgery may become more obvious in this timeframe. Most children will continue to focus therapy efforts on alignment, strength, and preventing secondary problems.
Beyond 1—2 Years: Some children may still gain function past age two. However, if key movements (like lifting their arm overhead or rotating it outward) are limited, long-term weakness or movement restrictions are more likely. At this stage prognosis usually shifts towards managing long-term complications. In some cases, tendon transfers or shoulder reconstruction may be considered.
Explore Related Topics
Erb's Palsy FAQs
Written and Medically Reviewed by:
Cerebral Palsy Hub Team
Cerebral Palsy Hub was founded to help support children and their families with cerebral palsy and to create a safe space for those affected. We strive to provide the most accurate, up-to-date information, and tools to help give your child the life they deserve.
Last Updated: December 10, 2025
