Forensic anthropology 153
examine any garments associated with the remains for defects that
may correspond to the injuries.
Blunt force injury: Blunt force injuries are the most common form of
mechanical trauma. Caused by relatively slow loading rates, they
allow bone to deform before failure, producing characteristic dam-
age patterns. Because the energy (E) transferred to the bone is half
the product of the mass (m) of the object striking it and the square
of the velocity with which it is delivered (v^2 ), velocity will make the
greatest contribution to the damage observed. Keeping this relation-
ship in mind, one can reduce the number of possible scenarios leading
to a particular injury. A second important consideration is the area
through which the energy is delivered. A blow of 75 ft.lbs.s–1 delivered
by the flat side of a 12 × 2 inch plank will do less damage than the
same amount of energy delivered by the 7 square inch face of a sledge
hammer. The same is true of comparable energies delivered to curved
vs. flat surfaces, e.g., when the hypothetical plank is slammed against
the body wall vs. the curve of the parietal bone. Likewise, equal force
applied to a healthy vs. diseased bone (tumor, osteoporosis, etc.)
will often result in different degrees of damage. When examining
unidentified skeletal remains, it is important to remember that some
mechanical injuries may be incidental. These will usually appear as
perimortem injuries, although they do not contribute to death. For
example, severe skull or cervical fractures may have been caused by
falling down a staircase after a fatal coronary, or from a utility pole
after a lethal electrical shock. The author once had the opportunity
to examine skeletal material recovered from a collapsed area of a long
abandoned historic mine. Though many of the bones were broken,
it was impossible to know whether the two victims had expired from
asphyxia, dehydration, or the crushing effects of the collapsing shaft.It is important to consider that force applied to one part of the skeleton
may be transferred, causing damage elsewhere. Shock from a hard landing
may be transferred through the legs, damaging the bones of the pelvis or
spine, and vertical loading of the spine from below has sometimes resulted
in ring fractures of the skull base. A blow to the left gonial angle may cause
a hinge fracture of the right mandibular ramus when the head is arrested
against an unyielding surface, and the same principle applies in the classic
contrecoup skull fracture. Reconstruction of a shattered skull, though
time-consuming, may provide information about the number and order of
strikes, or reveal a pattern that suggests the nature or class of weapon used.
In a recent case, the decedent’s skull was crushed by the right rear wheel of
the vehicle from which she “fell.” Arrested later, other occupants of the car
alleged that she “opened the door in an intoxicated state and fell beneath the