DefinitionOpisthotonos is a condition in which the body is held in an abnormal posture. It usually involves rigidity and severe arching of the back, with the head thrown backward. If a person with opisthotonos lays on his or her back, only the back of the head and the heels would touch the supporting surface.See: Abnormal posturingConsiderationsOpisthotonos is much more common in infants and children than in adults. It is also more exaggerated in infants and children because of their less mature nervous systems.Common CausesOpisthotonos may occur in infants with meningitis, where it is a sign of irritation of the membranes surrounding the brain and spinal cord (meninges).It may also occur as a sign of depressed brain function or injury to the nervous system.Other causes may include:Brain t