Why do dead people look stiff?
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.
Do bodies go stiff when they die?
Rigor mortis refers to the state of a body after death, in which the muscles become stiff. It commences after around 3 hours, reaching maximum stiffness after 12 hours, and gradually dissipates until approximately 72 hours after death.
Why does the body tense up after death?
Because the heart no longer pumps blood, gravity begins to pull it to the areas of the body closest to the ground (pooling), a process called livor mortis. Beginning approximately in the third hour after death, chemical changes within the bodys cells cause all of the muscles to begin stiffening, known as rigor mortis.