<Table> <Tr> <Td> </Td> <Td> This article needs attention from an expert in Biology . Please add a reason or a talk parameter to this template to explain the issue with the article . WikiProject Biology may be able to help recruit an expert . (August 2012) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs attention from an expert in Biology . Please add a reason or a talk parameter to this template to explain the issue with the article . WikiProject Biology may be able to help recruit an expert . (August 2012) </Td> </Tr> <P> Cadaveric spasm, also known as postmortem spasm, instantaneous rigor, cataleptic rigidity, or instantaneous rigidity, is a rare form of muscular stiffening that occurs at the moment of death and persists into the period of rigor mortis . Cadaveric spasm can be distinguished from rigor mortis being stronger stiffening of the muscles that can't be easily undone like rigor mortis . The cause is unknown, but is usually associated with violent deaths happening under extremely physical circumstances with intense emotion . </P> <P> Cadaveric spasm may affect all muscles in the body, but typically only groups, such as the forearms, or hands . Cadaveric spasm is seen in cases of drowning victims when grass, weeds, roots or other materials are clutched, and provides evidence of life at the time of entry into the water . Cadaveric spasm often crystallizes the last activity one did before death and is therefore significant in forensic investigations, e.g. holding onto a knife tightly . </P>

What is it called when a dead body moves