Erb’s Palsy (Birth Brachial Plexus Injury)

The nerve network supplying the shoulder and arm was stretched during delivery, most often with shoulder dystocia, a prolonged or instrumental delivery, or high birth weight. The affected arm moves less, lies close to the body and the grip may be weak.

It is a consequence of the birth process and not something a parent caused or could have prevented. Families are frequently carrying guilt about this and it is worth saying directly.

Nerves recover slowly. While they do, the shoulder joint stiffens and the muscles waste, and a shoulder allowed to contract will limit function later even if the nerve recovers well.

The first three to six months are therefore the critical period, and treatment begins as soon as the diagnosis is made rather than at a review appointment months later 1 2.

Passive range-of-movement work several times daily, taught to the parents and done at home — this is the main intervention and the therapist's job is largely to teach and check it. Positioning, muscle stimulation, and active movement training as recovery allows.

Play-based activities that encourage use of the affected arm, because an arm that is not used does not develop even when it could move.

Recovery of elbow flexion against gravity by around three months is a useful early marker 1. Where the expected milestones are not met, surgical opinion is sought at the point it is still useful rather than after the window has closed.

Surgery is needed in a minority. Most children recover substantially, and a proportion have some residual weakness or shoulder restriction that is managed long term.

Examination in the first three months — movement at the elbow, wrist and fingers, and whether Horner’s syndrome (a smaller pupil and drooping eyelid on that side) is present — is the main guide to which infants will need nerve surgery 1 2. Infants whose injury is limited to the upper part of the plexus and who bend the elbow normally by about four months have an excellent outlook for full function 2.

Those who do not need specialist surgical assessment rather than continued waiting, because nerve reconstruction has a window and it closes.

Two problems deserve attention. The shoulder joint can develop abnormally, and an early sign is that the arm can no longer be turned outwards fully; when this passive outward rotation becomes limited, an ultrasound can check the joint, ideally so that any problem is found and treated within the first year 2.

At the elbow, a bend that will not fully straighten is the most common lasting problem. It comes from the weakened elbow-bending muscles growing more slowly than the bone, so it tends to worsen during growth spurts; stretching, night splints or serial casting aim to keep it below 30°, a degree of bend that does not interfere with daily activities 2.