Abstract:
A question remains as to whether specific criteria can be used to differentiate perimortem and postmortem breakage patterns in deer femora. The purpose of this experiment was to discover if fracture characteristics, such as smooth or rough fracture surfaces, are statistically correlated with bone condition (old, new) or bone end (proximal, distal). Two experimental groups were used (postmortem; n = 46; perimortem; n = 41). Dependent variables (DV) were the presence or absence of (a) right angles, (b) acute angles, (c) jagged edges, (d) curved edges, (e) smooth bone surfaces, (f) rough bone surfaces, (g) transverse fractures, (h) butterfly fractures, (i) number of fracture lines, and (j) number of pieces created from the break. Independent variables (IV) were (a) the condition of the bone (old, new) and (b) end of the bone (proximal, distal). The study hypothesis was that perimortem fractures would contain more acute than right angles and more smooth than rough surfaces and that postmortem fractures would contain more right than acute angles and more rough than smooth surfaces. A significant correlation among variables may help future researchers to categorize unknown bones. Bones were fractured using a Dynatup 8250 Drop Weight Impact Test Machine (DWITM). New bones were tested within 2 days of receipt, and old bones at least 60 days following receipt. Distal ends were secured in a vice, while proximal ends were placed on a foam pad. Descriptive statistics, correlational analyses, and analysis of variance tests were conducted, with an alpha level of p = 0.05 indicating statistical significance (two-tailed). Significant correlations were observed between bone condition (old, new) and right angles (rho = -.463, p < .001, old bones tend to exhibit a right angle); acute angles (rho = .415, p < .001, new bones tend to exhibit an acute angle); smooth bone surface (rho = .379, p < .001, new bones tend to exhibit a smooth fracture surface); and rough bone surface (rho = -.420, p < .001, old bones tend to exhibit a rough fracture surface). Results may be applicable to scientists in the fields of bioarchaeology and forensic science.
