What is rigor mortis?

Rigor mortis refers to the postmortem stiffening of the body’s muscles due to biochemical changes that occur after death. This phenomenon is primarily caused by the depletion of adenosine triphosphate (ATP) in muscle tissues, leading to a state where the muscles become tense and rigid. Initially, after death, the body experiences a phase of relaxation, but as rigor mortis sets in, typically starting within two to six hours and reaching its peak around 12 to 24 hours postmortem, the body becomes increasingly stiff.

Understanding rigor mortis is crucial in forensic pathology as it helps professionals determine the time of death. This process eventually subsides as decomposition progresses and the muscles begin to break down.

In contrast, the pooling of blood post-death, known as livor mortis, involves the settling of blood in the body’s lowest points due to gravity. The cooling of the body after death, referred to as algor mortis, involves the temperature drop of the body over time. The process of decomposition encompasses a broader range of changes that occur as the body breaks down biologically, ultimately making rigormortis a specific aspect of the postmortem changes that occur. Therefore, the precise definition of rigor mort