Site of injury: One region of upper trunk of brachial plexus is called Erb’s point. Six nerves meet here. Injury to the upper trunk causes Erb’s paralysis

Causes of Injury: Undue separation of the head from the shoulder, which is commonly encountered in the following

1. Birth injury
2. Fall on the shoulder
3. During anesthesia

Nerve root involved: Mainly C5 and partly C6

Muscles paralyzed: Mainly biceps brachii, deltoid. brachialis and brachioradialis . partly supraspinatus, infraspinatus, and supinator

Deformity and position of the limb

• • Arm: H hangs by the side; it is adducted and medially rotated.
  • Forearm: Extended and pronated

The deformity is known as ” policeman ‘s tip hand ” waiter’s tip hand or porter’s tip hand ‘

Disability

The following movement are lost

• Abduction and lateral rotation of arm at the shoulder joint
• Flexion and supination of the forearm
• Biceps and supinator jerks are lost.
• Sensation is lost over a small area over the lower part of the deltoid