The shoulder and upper arm contain a group of nerves called the brachial plexus, which is made up of nerves that emerge from the spinal cord. From the brachial plexus, branches of nerves extend down the arm to the hand and fingers. A type of brachial plexus palsy, or weakness, Erb’s palsy is an injury that affects the upper nerves of the brachial plexus. This injury occurs in infants, often as a result of overstretching of the nerves during birth, and can cause weakness or loss of movement in the affected arm.
- Avulsion. The most serious form of Erb’s palsy, avulsion occurs when a nerve ruptures from the spinal cord.
- Neuroma. This type of injury occurs when damaged nerve fibers form scar tissue that presses on nearby healthy nerves.
- Neuropraxia. Most cases of Erb’s palsy occur because of overstretching of the brachial plexus nerves during birth, which is called neuropraxia.
- Rupture. A serious injury, rupture is when a nerve tears.
- Arm rotates inward with wrist bent and fingers extended
- Loss of sensation in the arm
- Partial or total loss of movement in the arm
- Poor grip strength
- Weakness in the affected arm
- Get tested for gestational diabetes. Mothers-to-be with this condition are more likely to have a large baby, which increases the risk of Erb’s palsy.
- Communicate with the obstetrician before and during labor about the safest positions for delivery.
- Mothers-to-be should ensure their labor and delivery team has a plan if baby’s shoulder gets stuck in the birth canal during delivery.
- Shoulder dystocia (baby’s shoulder is squeezed in the birth canal during delivery)
- Feet-first delivery
- Large baby
- Low or mid forceps delivery
- Previous birth that resulted in a brachial plexus injury
- Second stage labor longer than one hour
- Small mother
- Vacuum-assisted delivery
- Physical examination. The baby’s pediatrician or another provider will examine the affected arm for loss of movement, weakness and limpness. The provider may check the Moro reflex, which is baby’s involuntary reaction to a momentary loss of head support. If the Moro reflex is missing on the affected side, Erb’s palsy may be present.
- Imaging tests. These may include X-ray, ultrasound or MRI, to check for bone or tissue damage.
- Nerve tests. A provider may order an electromyogram to check for nerve-related muscle damage. A nerve conduction study may be necessary to assess the functioning of nerve pathways.
- Careful monitoring. Erb’s palsy often goes away on its own. In the meantime, the baby’s provider will monitor her symptoms.
- Physical therapy. With instruction from a physical therapist, parents will need to help their baby improve arm strength, flexibility and range of motion with daily exercises.
- Surgery. If Erb’s palsy doesn’t improve with physical therapy, the baby’s healthcare provider may recommend surgery, typically before the baby’s first birthday. Surgical options include using a nerve or a portion of a nerve from elsewhere in the child’s body to repair or replace an injured nerve in the arm.
- No matter what type of treatment the baby receives, his or her healthcare provider will follow up on a regular basis to be sure the baby is improving. If the baby has surgery, the healthcare provider will provide detailed instructions for post-surgical care.