The various parts of the human body are probably injured by external traumatic agents in direct proportion to the percentage of body surface area of any given part to the whole. This regional distribution of wounds sustained in battle by United States troops has been studied and compared in our three major wars.
Since the upper and lower extremities comprise 61 per cent of the total body area and thereby offer almost two thirds of the target to the potential traumatizing agent, wounds or injuries of the extremities are sustained in that proportion in war and probably in peace. Since the wound or injury of the extremity is far less apt to terminate fatally than is that involving chest, abdomen or head, there is an even greater number of these casualties of the extremities which reach the hospital for treatment. Of the wounded in action, 73 per cent in the