Erb’s Palsy Causes

While several birth injuries can happen at various times in an infant’s development, birth, or during the perinatal experience out of the womb, Erb’s palsy typically happens during the delivery period and often towards the end of a long, difficult delivery. Since Erb’s palsy involves nerve damage in the shoulder area,  it is widely viewed as a birth injury that is preventable as it’s usually caused by the physician pulling the infant too rough or pulling in an abnormal way.

Cephalo-Pelvic Disproportion

One of the causes for Erb’s palsy is due to cephalo-pelvic disproportion (CPD), a condition that occurs when the infant is proportionately too large for the birth canal. This is something that physicians are generally able to diagnose during the last few weeks of pregnancy.

Many doctors will prefer to deliver the baby via caesarian section (C-section) to avoid possible complications. Erb’s palsy is one of the potential problems related to CPD because as the child enters the birth canal and pushes through, the disproportionate size could cause the child to squeeze through, pushing the head in shoulder forcefully in opposite directions, causing damage to the brachial plexus nerves in the shoulder.

Head-First Delivery

When an infant’s head gets stuck , the head pulls away from the shoulders, causing shoulder dystocia. Another scenario, however, and one that is more likely is that the baby’s head comes out of the cervix and the baby gets stuck. To aid with delivery, the doctor or nurses pull the baby out, thus causing an unnatural pull between the baby’s head and the shoulder.

Breech Delivery

When infants are in the breech position, an observant doctor will typically know weeks before delivery. Most physicians prefer to schedule a C-section so that there are no unnecessary risks and complications with the delivery.

One of the risks includes the baby getting stuck in the birth canal, causing the brain to be compressed for too long, causing a brain injury, or potentially kinking the umbilical cord, causing oxygen deprivation.

Even if the infant doesn’t get stuck during the delivery, there are still inherent risks: Erb’s palsy comes from the child being delivered feet-first, which leads the medical professionals no choice but to pull the baby out from the feet, causing the arms to go over the baby’s head, and for unnatural stress to be put on the brachial plexus nerves.

Forceful Arm Pulling

Another possible cause of Erb’s palsy is when a physician pulls on the baby’s arms. It is rare that a baby would come out arms-first, so the pulling would then be committed after delivery, possibly from picking up a baby by his or her arms, causing unnatural stress.


Although one of the most common reasons Erb’s palsy occurs is when a physician pulls and tugs an infant too hard during a regular delivery, in rare cases, the disorder can happen during a C-section. According to National Institutes of Health (NIH), lateral traction during a C-section may cause Erb’s palsy, yet this is rare and maternal forces may also play a part.

Additional Information For Parents

Brachial plexus palsy or Erb’s palsy is a birth injury that is recognized as generally an injury that could have been prevented with the correct medical care. If the infant is breech position or  has CPD, an observant, knowledgeable physician knows about this weeks before delivery, which provides plenty of time to schedule a C-section.

Around 1 to 2 infants per 1,000 births will develop some sort of brachial nerve injury. Although improved techniques utilized during delivery can help prevent brachial plexus injuries, it hasn’t been completely prevented. If you’re currently pregnant, don’t hesitate to ask your physician about your baby’s weight and position if you haven’t been informed.

Treatment Options

If your infant suffers from Erb’s palsy, treatment will depend how severe the injury is which nerve was damaged. In cases of mild forms of Erb’s palsy, it usually clears up on it’s own within a few months. You can help the process by gently massaging the affected arm and performing range-of-motion exercises. Many parents enroll their infants in physical therapy for the most optimal results.

In severe cases of Erb’s palsy, getting treatment is crucial as failure to do so may result in full paralysis in the affected arm. Treatment for severe cases may consist of surgery and in rare instance, nerve grafts and nerve transfers. Infants with severe Erb’s palsy, even with treatment, may experience problems for several years afterwards, including prolonged weakness in the affected arm and limited range of motion.