<prompt> Concerning brachial plexus, which of the following facts are trueFormed by spinal nerve C5- C8 and T1Most common site of injury is upper trunkInjury may occur, during breech deliveryRadial nerve is branch of medial cord  <response>: Brachial plexus is formed by the anterior primary rami of spinal nerves C5-C8 and T1, with contribution from the anterior primary rami of C4 and T2. Radial nerve is a branch of posterior cord. Injury to the upper trunk causes Erb;s paralysis. B D Chaurasia 7th edition Page no: 58 