Pressure on the neck calculated for any point along the ligature.
It had been experimentally shown that disfunction of the airways, major arteries and veins occurs in neck compression due to the violence of different strengths. These differences in the vulnerability of the neck anatomical structures determine the sequence and dynamics of the vital function disorders in strangulation, as well as its morphological features. The purpose of this study was to calculate the value of specific pressure P, which affects the neck along the ligature. Mathematical modeling method was used. Cylinder served the model of the human neck. It was found that P-value is directly proportional to the loop tension and inversely proportional to the radius of the curvature and neck-ligature contact area. Thus, in horizontal neck encirclement the strangulation groove forms a circumference, and P-value is invariable along the loop, as in typical cases of homicidal strangulation. In oblique position of the loop it makes an ellipse with changeable curve curvature, as in most hangings. As the formulas and graphs presented show, the increasing deflection of the loop towards the transverse plane results in increase in P-amplitude, mostly at the expense of its minimal indices (up to hundred per cent) rather than maximal ones (within 20% range). At the same time there are narrow zones along the loop, where the P-value remains almost invariable irrespective of loop deflection degree. The results of the study may be useful for investigation of thanatogenesis and pathomorphology of strangulation, including its experimental modeling.
Khokhlov
V D
VD
Bureau for medico-legal expertise of St. Petersburg, 10, Ekaterininsky Ave., 195067 St. Petersburg, Russia. biblmechn@soros.spb.ru
D000402:Airway Obstruction / Q000503:physiopathology; D001696:Biomechanical Phenomena; D005554:Forensic Medicine; D006801:Humans; D008953:Models, Anatomic; D009333:Neck / Q000503:physiopathology*; D019838:Neck Injuries / Q000503:physiopathology*; D011312:Pressure; D013405:Suicide