Rigor mortis------ (Latin: rigor "stiffness", mortis "of death") is one of the recognizable signs of death, caused by chemical changes in the muscles after death, causing the limbs of the corpse to become stiff and difficult to move or manipulate.[1] In humans, it commences after about three to four hours, reaches maximum stiffness after 12 hours, and gradually dissipates from approximately 24 hours after death