Damage to the upper nerves that make up the brachial plexus tends to occur when your shoulder is forced down, and your neck stretches up and away from the injured shoulder. The lower nerves are more likely to be injured when your arm is forced above your head. These injuries can occur in several ways:

  • Contact sports. Many football players experience burners or stingers, which can occur when the nerves in the brachial plexus get stretched beyond their limit during collisions with other players.
  • Difficult births. Newborns can sustain brachial plexus injuries when there are problems during birth, such as a breech presentation or prolonged labor. If an infant's shoulders get wedged within the birth canal, the force used to pull the baby free also can damage the nerves in the brachial plexus. Most often, the upper nerves are injured, a condition called Erb's palsy. Total brachial plexus birth palsy occurs when both the upper and lower nerves are damaged.
  • Trauma. Vehicular accidents, especially motorcycle accidents, and boating accidents can result in brachial plexus injuries. Animal bites and bullet or knife wounds also can damage the brachial plexus.

A rare condition known as Parsonage-Turner syndrome (brachial plexitis) causes brachial plexus inflammation with no apparent shoulder injury.

Feb. 24, 2011