Abstract
Post-mortem movement relating to the disarticulation or positional change of entire limbs is relevant to a forensic investigator when examining a deceased person. Understanding that the position a body is found is not necessarily the way it was left changes the approach an examiner must take when investigating any death. This study quantified post-mortem movement of a human donor decomposing in an Australian environment over 16 months: 1) progressive measurement of the angles of joints; and 2) distance of separation between the articulating points of bones. ImageJ software was used to calculate angles and the distances between structures from time-lapse images. Movement was detected at all joints of the upper and lower limbs, occurring at all stages of decomposition across the study. Significant movement of the joints occurred as a result of bloat during the early stages of decomposition, and again during the advanced stages of decomposition as the soft tissue desiccated. Disarticulation was observed in the late stages of decomposition in all limbs and was not exclusive to short or long bones. Disarticulation also generated significant movement between skeletal structures in late decomposition. The results demonstrate that it is essential to consider post-mortem movement when investigating unexplained deaths.
Lamerton, Paul