Arm weakness

happens with a stretch to the nerves of the brachial plexus.


a word for arm pit.  Axillary nerve is also a word for a terminal branch of the brachial plexus that sends messages to the deltoid muscle to lift the shoulder into the air.


disruption to the axon of the nerve which leaves the nerve partially intact.  Surgical repair may or may not be required.

Brachial plexus

a collection of nerves that supply messages to the arm to move and feel.  The brachial plexus starts with the C5, C6, C7, C8, and T1 nerve roots from the spinal cord and ends with the axillary, radial, musculocutaneous, ulnar, and median nerves.


the distal nerves of the brachial plexus that connect with the muscles, comprising the Axillary, Musculocutaneous, Median, Radial and Ulnar nerves


the muscle that bends the elbow.  Surgery may not be needed if a baby can bend the elbow between 3-9 months of age.

Benediction sign

a posturing of the hand when trying to make a fist that happens when there is injury to the median nerve.


is a Latin term for neck.  Cervical nerves 5, 6, 7, and 8 are part of the brachial plexus along with thoracic nerve 1. 

Constraint therapy

includes the use of casts on the stronger arm to help the weaker arm improve.


stiffness in the joint leading to lack or range of motion caused by bony changes in the joint or shortening of the muscles around that joint.


used to immobilize a joint after a shoulder or elbow surgery.

Diagnostic tests

may be recommended to help evaluate the extent and severity of the stretch to the brachial plexus.  EDX represents Electrodiagnostic tests that are used to assess the continuity and function of a nerve. MRI is Magnetic Resonance Imaging. CTM is Computed Tomography Myelogram.

Erb’s Palsy

a term used to describe the type of brachial plexus palsy that involves the upper 2 or 3 nerves: C5, C6 and sometimes C7.  This is the most common type of brachial plexus palsy.


a word that means to straighten the arm.


describes a movement involving bending of a joint. 


Flaccid is weakness with lack of muscle firmness.

Horner’s syndrome

a droopy eye, a lack of sweating on the same side of the face, and the inability for the pupil to enlarge on the same side of the brachial plexus palsy.


commonly used to express the number of new cases during some time period, but it is better represented as a measure of the risk of developing some new condition within a specified period of time. The incidence of neonatal brachial plexus palsy is 1-4 cases per 1,000 live births in the United States.


means that messages are traveling from the brain through the nerve to the muscle without interruption.


can become tight or contracted if you do not stretch or do exercises.

Klumpke’s Palsy

the rarest form of a brachial plexus palsy in which the lower 2 or 3 nerves of the brachial plexus were stretched, ruptured or avulsed causing the hand to be weak.

Long-term weakness

is a possibility with brachial plexus palsy.

Musculocutaneous nerve

the branch of the brachial plexus that innervates the biceps muscle.  

Median nerve

the branch of the brachial plexus that innervates the muscle that pronates the forearm and bends the fingers especially the thumb, pointer and middle fingers.


combined disorganized mass of regrowing nerves and scar tissue that forms when the nerves of the brachial plexus have been stretched or torn.

Neurotization or nerve transfer

a surgical procedure where a part of a healthy nerve is re-routed to a nerve that is not functioning properly or directly into a muscle that is weak.


release of a nerve sheath by cutting it along the length of the nerve and/or theoperative breaking up of perineural adhesions

Nerve graft repair

a surgical procedure where a nerve from another portion of the body is used to replace the nerve that is not functioning properly to serve only as a conduit through which a regrowing nerve must pass.  Usually, the sural nerve is used as nerve graft.


a blockage of the outer layers or membrane of nerves due to stretch or compression.  Usually recovery occurs in 4-6 weeks.


complete separation of all layers of a nerve.  Surgical repair to the nerve is necessary to recover function.

Occupational / Physical Therapy

often recommended to assist a child with a brachial plexus palsy with strengthening the weak arm to ensure achievement of independence with self-help or development of large and small muscle motor skills.

Pre-ganglionic nerve injury / avulsion

when the nerve is pulled away from the spinal cord and is the most severe form nerve injury.  Spontaneous recovery does not occur.   A Horner’s sign is associated with avulsion of T1.  Poor prognosis results without surgical intervention.

Post-ganglionic / rupture

when the nerve is disrupted outside of the spinal canal.  Surgical intervention may be indicated. Guarded prognosis without surgical intervention.

Phrenic nerve

innervates the diaphragm.  The diaphragm is a muscle that separates the chest from the abdomen that assists with breathing with breathing.


the motion of turning the palm downward as if pouring soup out of the bowl.


means the head is misshapened.  The flattening of the back of the head  commonly results from torticollis.  The treatment for acquired plagiocephaly is helmet therapy to correct the shape of the head.


stretch, rupture or avulsion of the entire brachial plexus.  This is the most extensive form of brachial plexus palsy.

Range of motion exercises

an important part of the care of a baby with brachial plexus palsy.  Exercises are often recommended every diaper change during the day.  Without full passive motion, limitations in active movement and joint contractures results.

Risk factors

with brachial plexus palsy can include: pregnancy related diabetes, babies that weigh more than 4.5 kg, and shoulder dystocia.

Radial nerve

a branch of the brachial plexus that allows the extension of the elbow, wrist, and fingers. 

Shoulder dystocia

when the shoulder of the baby is lodged against the mother’s pelvic bone (sometimes the tail bone) during the delivery of the baby.

Surgery (nerve reconstruction)

is sometimes needed to re-connect, repair, or re-route the nerves to help the arm with acquiring the messages to move and feel.


the motion of turning the palm up as if you are holding a bowl of soup.

Steindler effect

the use of extreme wrist extension to assist with elbow flexion. Note that the Steindler procedure is a moving of muscle along the humerus that facilitates flexion of the elbow.

Sural nerve

located in the back of the leg and supplies sensation to the side of the foot.  It is often removed from the back of the leg and used in the repair of the brachial plexus nerves that were stretched or torn.

Trumpeter’s Sign

describes the position of the weak arm with the elbow elevated and looks as if the child is playing a Trumpet resulting from weakness in the muscles that externally rotate the arm.


the muscle that straightens the elbow.  A good sign of recovery occurs if a baby can straighten his/her elbow at one week of age.


can happen in children with or without brachial plexus palsy.  Torticollis is characterized by tightness in the muscles of the neck that turns the head to the side.  The treatment for this includes neck exercises inclusive of belly time.  Severe or prolonged cases of torticollis can lead to plagiocephaly.


can help the doctors gather information about the diaphragm, shoulder joint, or nerves of the brachial plexus.

Ulnar nerve

the branch of the brachial plexus that serves most of the muscles in the hand.  Ulnar nerve helps with spreading the fingers apart and bringing them together.


also referred to as paralysis or paresis and can result from muscle atrophy with or without denervation. Waiter’s tip

the posture of the arm in children with brachial plexus palsy characterized by shoulder internal rotation, shoulder adduction, elbow extension, forearm pronation and wrist flexion with fingers partially flexed.  It looks as though the child is ready to secretly accept a tip behind his/her back.

Winging of the scapula

can occur when the shoulder blade lifts away from the chest wall due to weak shoulder muscles. Some winging is expected; significant amounts of scapular winging that interfere with a child’s ability to move may require therapeutic or surgical interventions.


is the amount of time that may be needed for the nerves of the brachial plexus to regenerate at a rate of 1 mm per day.