What is rigor mortis?

Rigor mortis refers to the postmortem stiffening of muscles that occurs after death. This process is primarily caused by chemical changes in the muscles as the body starts to break down. After death, ATP production ceases because metabolic processes stop, which leads to the muscles being unable to release the myosin heads from actin filaments in muscle fibers. As a result, muscle contraction occurs and the muscles remain in a contracted state, leading to stiffness. This phenomenon typically begins within a few hours after death and can last for several days, depending on various factors such as ambient temperature and the individual's physical condition prior to death.

Understanding this process is important in the fields of forensics and biology, as it provides insights into the time of death and the physiological processes that continue to occur after the heart stops beating.