A study of the impact of weathering upon the minmal force required to fracture bone

Date
2013
DOI
Authors
LaCroix, Marcelle N.
Version
OA Version
Citation
Abstract
This project examined the effects of weathering processes on the minimal force required to fracture long bones exposed in a coastal microhabitat located in Southeastern Massachusetts, U.S.A. The experimental remains consisted of isolated white-tailed deer (Odocoileus virginianus) long bones as a proxy for human and other large vertebrate remains. The sample contained both raw (unprocessed) and boiled (processed) bones, to mimic forensic and archaeological settings, respectively. This study was conducted over a period of nine months, during which stages of weathering and breaking force of bone were recorded to establish if there is a correlation between weathering processes and the minimal force required to fracture bone. The bones were removed from the microhabitat at monthly intervals and fractured using a bone-breaking apparatus that measures force. It was hypothesized that the weathering processes in this microenvironment will weaken the bone and therefore have an impact on different fracture attributes. Studying certain fracture attributes, such as force required to fracture and fracture morphology, will provide more information regarding the impact of weathering upon bone biomechanics and subsequently may be of assistance in determining the postmortem interval. Examining fracture characteristics of the exposed bones will offer a comparison between perimortem and postmortem breakage patterns in exposed bones. Additionally, the weathering data collected were micro- habitat specific. This study confirmed the hypothesis and concluded that the main effect of exposure time to weathering elements on the minimum force required to fracture long bones was significant and influenced several of the fracture characteristics defined by Wheatley (2008). The length of exposure had an effect on texture of the fracture surface, the fracture angle produced, and the number of fragments produced. Additionally, although the results were not statistically significant, analysis of the shape of broken ends and the presence of fracture lines displayed a trend relative to the length of exposure. The type of fractures produced did not show a statistically significant relationship to the length of exposure time. Although a portion of the animal bone sample was processed and juvenile, neither processing nor age was found to significantly affect the force required to fracture bone nor did these factors impact the type of fracture characteristics produced in this study.
Description
Thesis (M.S.)--Boston University
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