Question of the Day... Erb's Palsy

This question was taken from the Coventry Oct 2012 exam.

Question:
What is the position seen in Erb's Palsy?

Answer:

"Waiter's tip" position

What is Erb's palsy?

Erb's palsy is a lower motor neuron lesion that common occurs when the head and shoulders are forced apart, stretching and tearing the upper roots of the brachial plexus.

Which roots are affected in Erb's Palsy?

C5 and C6

Why does the patient present with the "Waiter's tip"?

Paralysis of the deltoid prevents the arm from being raised.

Paralysis of the biceps brachii and brachialis (flex and supinate elbow) means that the arm is limp and the forearm is pronated.