Study of Rigor Mortis and Factors Affecting its Development for Determination of Postmortem Interval

Rigor mortis, a physico-chemical change that occurs within muscles after death, is one of the significant component in determination of post-mortem interval in warm countries like India, though its development is affected by various factors. This prospective study was carried out to evaluate and interpret variations in development of rigor mortis with respect to cause of death and media from which the body was brought and to determine time and sequence of its development in various muscle groups and joints. It was observed that commencement and full development of rigor mortis is earlier in deaths due to infectious conditions, regional injuries, head injury and deaths due to poisoning as compared to that of deaths due to hanging. Rigor commenced late and developed fully late in water media as compared to air media. It appeared first in the eyelid, then in the face, followed by neck, upper limbs, trunk, lower limbs and lastly the fingers and toes. It disappeared in the same order as it appeared.