Rigor mortis

Rigor mortis is the natural stiffening of muscles that occurs after death. When a person dies, the process of chemical changes causes muscles to lose flexibility and become rigid. This typically begins within a few hours post-mortem, peaks around 12 hours, and then gradually relaxes over time as tissues break down. Rigor mortis helps forensic experts estimate the time of death and is a normal part of the decomposition process. It varies based on factors like temperature, age, and physical condition.