Factors Affecting Estimation of Time Since Death by Rigor Mortis

One of the most difficult features of rigor mortis to explain is the great variation in the interval between death and the first signs of stiffening in the muscles. This study was conducted with an objective to determine the order of appearance of rigor mortis in different body parts and its relation to age, built and season. Earliest onset of rigor mortis was seen in 1–2 hours after death with maximal onset interval being 4–5 hours. Most of the cases showed onset of rigor mortis in eyelids in 3–4 hours, jaws in 4–5 hours, neck muscles in 6–7 hours, upper limbs in 8–9 hours, lower limbs in 10–11 hours, finger &toes in 11–12 hours. Children and elderly had early onset, development and passing off of rigor mortis as compared to adults. Thin-built persons also had early onset, development and passing off of rigor mortis as compared to well-built persons. Summers showed early onset, development and passing off of rigor mortis as compared to winters.