What is rigor mortis?

Rigor mortis is a well-documented physiological process that occurs after death, characterized by the stiffening of the body's muscles. This process begins several hours post-mortem, typically around 2 to 6 hours after death, as biochemical changes occur in the muscle tissues.

After the cessation of life, ATP (adenosine triphosphate) production stops, which is necessary for muscle relaxation. Without ATP, myosin heads remain bound to actin filaments, leading to a sustained contraction and stiffness in the muscles. This condition can persist for up to 24 to 48 hours before ultimately resolving as the tissues begin to decompose.

Understanding rigor mortis is crucial for forensic science and medicine, as it serves as an important indicator of the time of death and can assist in determining post-mortem intervals in criminal investigations or medical examinations. The other options describe situations that do not accurately represent rigor mortis, which is specifically about the stiffening phenomenon following death.