This is the Final Overview of a research project that used impact experiments on adult human cadaver skulls to produce baseline documentation of the effects of various forensically relevant variables on cranial fracture initiation, propagation, and patterning; and specimen-specific computational models were used to examine a mechanistic basis for the locations of cranial fracture initiation.
The subjects of this study were 39 isolated, fresh human cadaver heads obtained from the University of Maryland Department of Anatomy and the Michigan State University Department of Anatomy. All specimens were de-identified prior to receipt. A total of 72 impact experiments were performed on 24 head specimens (males, age 50 or older at death) to investigate the effects of implement shape, input energy, and impact number on cranial fracture development. A key finding from the 12 low-energy, single-impact experiments was the linear fracture initiating peripheral to the point of impact (POI). A key finding from the low-energy multiple impact experiments was that implement shape influenced the frequency of certain fracture types. A key finding from the high-energy impact experiments was that peripheral initiation was observed in 6/12 impacts. A key finding from the high-energy multiple impact experiments was that impact energy and implement shape both influenced the frequency of fracture types. All three implement types produced circular defects and bone plugs more often in high-energy than low-energy impacts. A key finding of the comparisons between thickness distributions and fracture patterns was that skulls of increased or reduced thickness deviated from the hypothesized fracture pattern for their respective impacting implement. This unique dataset provides a valuable resource for comparing unknown trauma encountered in forensic cases to known trauma produced in scientific experiments. This enables death investigators to improve their effectiveness in interpreting blunt-force cranial and mandibular fracture patterns. Extensive appended tables, figures, and references