What is rigor mortis?

Rigor mortis refers specifically to the phenomenon that occurs in the body after death, where the muscles become stiff and rigid. This postmortem stiffening is a result of biochemical changes in the body, particularly the lack of adenosine triphosphate (ATP) that normally allows muscles to relax. After death, the body undergoes this process typically within a few hours, ensuring that the muscles are unable to flex or relax properly, which can last for several hours to a couple of days.

Understanding rigor mortis is essential in the field of forensics and mortuary science as it provides critical information about the time of death and the physiological changes that occur after a person has passed away. This is distinct from other processes like embalming or stages of decomposition, which are related but focus on different aspects of caring for the deceased.