Ultrasound Elastographic Measurement of Rigor Mortis in an Animal Model: A Feasibility Study for Improved Time-of-Death Estimates in Forensic Investigations.

OBJECTIVE. The purpose of our study was to assess the feasibility of 2D shear wave ultrasound elastography to quantitatively measure changes of rigor mortis. SUBJECTS AND METHODS. Muscle stiffness of two live pigs and nine sacrificed pigs was measured in kilopascals using ultrasound elastography. The nine sacrificed pigs were divided into three groups of three pigs each and placed in one of three environments at 90°F (32°C), 70°F (21°C), or 34°F (1°C). Ultrasound elastography of five muscles was performed at 1- to 2-hour intervals for up to 50 hours postmortem. For each pig and muscle location, the time to start, peak intensity, duration of peak, and time to decline of rigor mortis were identified from the graphs of muscle stiffness values over time. These outcome variables were then compared across ambient temperature, body weight, and age groups using the Wilcoxon rank sum test. RESULTS. Postmortem measurements show a rise, peak, and decline of muscle stiffness after death. Rigor mortis was highly significantly affected by ambient temperature (p < .001), was significantly affected by body weight (p = .04), and was not significantly affected by animal age or muscle location (facial vs truncal vs limb) (p > .50). Peak intensity of rigor mortis developed more quickly but attained lower levels of muscle stiffness at 90°F (80-100 kPa) compared with 70°F and 34°F (280-300 kPa) (p < .001). The duration of peak rigor mortis and the time to decline of rigor mortis were significantly longer for the lower temperatures (p < .001). CONCLUSION. Two-dimensional shear wave ultrasound elastography can quantifi-ably measure the trajectory of rigor mortis in an animal model. This new approach may have direct implications for human forensic investigations.

Putrefactive rigor: apparent rigor mortis due to gas distension.

Artifacts due to decomposition may cause confusion for the initial death investigator, leading to an incorrect suspicion of foul play. Putrefaction is a microorganism-driven process that results in foul odor, skin discoloration, purge, and bloating. Various decompositional gases including methane, hydrogen sulfide, carbon dioxide, and hydrogen will cause the body to bloat. We describe 3 instances of putrefactive gas distension (bloating) that produced the appearance of inappropriate rigor, so-called putrefactive rigor. These gases may distend the body to an extent that the extremities extend and lose contact with their underlying support surface. The medicolegal investigator must recognize that this is not true rigor mortis and the body was not necessarily moved after death for this gravity-defying position to occur.

Estudio de la rigidez cadavérica que presenta la Síndone de Turín / Study of the cadaveric rigidity presenting in the Shroud of Turin

En el estudio médico forense de la imagen sindónica llama la atención la intensa rigidez que se aprecia en la imagen corporal del Hombre de la Síndone. En este trabajo se estudia este fenómeno cadavérico y los posibles factores condicionantes que han podido modificar su normal evolución. Por otro lado, aprovechando la circunstancia de que esta rigidez se rompió y recuperó en hombros y brazos, se trata de determinar cronológicamente en que momento de la muerte se pudo producir tan sorprendente imagen (AU)

In the forensic study of the sindonic image it is necessary to pay attention to the intense rigidity that is observed in the corporal image of the Man of the Shroud. In this paper, this cadaveric phenomenon is analyzed and the possible conditioning factors which could have modified its normal evolution. Furthermore, taking into account the circumstance that this rigidity was broken and then recovered in shoulders and arms, we try to determine chronologically in which moment of the death this surprising image could be produced (AU)