Rigor mortis

 Rigor mortis is a postmortem change resulting in the stiffening of the body muscles due to chemical changes in their myofibrils. Rigor mortis helps in estimating the time since death as well to ascertain if the body had been moved after death. Position of the body in which the rigor mortis is established is indicative of the position of the body at the time of death, unless the position is disturbed by external forces or putrefaction.