Rigor mortis occurs when the muscles of the body begin to stiffen after death.
Rigor mortis is a condition that begins to develop in the body after death. Essentially, the action of rigor mortis is to initiate a process in which the muscles of the body begin to stiffen. In most situations, the corpse will begin to go through the process of rigor mortis about three hours after death and will continue to experience muscle stiffness for about thirty-six to seventy-two hours.
The state of rigor mortis can help determine the time of death during an autopsy.
Rigor mortis occurs due to the fact that once a living entity dies, there is no longer a constant flow of adenosine triphosphate or ATP to the muscles. ATP is necessary to help the muscles release from the state of contraction caused by the presence of calcium ions that flow into the muscles and act as a bridge or connection between the actin and myosin that is present in the muscle fiber. Without ATP to initiate the release of this connection, the muscles continue to contract, causing the body to become rigid. It is only when the muscle fibers begin to break down that the bond between the actin and myosin fibers breaks and the muscles of the body begin to lose their stiffness.
Rigor mortis sets in when there is no longer a steady flow of ATP.
The reality of rigor mortis often led to situations where the body was watched the first night after death. Commonly known as “sitting with the body,” the purpose of the action was to prevent stiff muscles from working the corpse into positions that were not suitable for funeral traditions. Often multiple people would stay with the corpse overnight and straighten limbs or lower the body’s torso into the prone position when stiff muscles caused a knee or elbow to bend, or the corpse to bend over. by the waist and appears to be sitting. .
The state of rigor mortis can also help coroners and law enforcement professionals determine the approximate time of death when the person did not die in a health care facility or while loved ones were nearby. Along with other factors, the degree of muscle stiffness that occurs during autopsy procedures helps reduce the time interval of death and thus provides valuable clues when foul play is suspected.