<prompt> Palmar surface of hand represents:1 of total body surface area2 of total body surface area3 of total body surface area4 of total body surface area  <response>: Ans. A: 1 of total body surface area The use of a patients own hand as a tool to estimate the area of burn injury is well documented. The area of the palmar surface of one hand has been estimated to be 1 percent of the body surface area. 