Blunt force trauma refers to injuries caused by impacts over a wide area rather than a puncture or penetration. It can affect many bones and cause fractures. Common weapons that cause blunt force trauma include bats, clubs, and other handheld objects. Analyzing the size, shape, weight of the object and pattern of fractures can provide clues about the nature and severity of the trauma. Blunt force to the skull can result in depressed fractures and LeFort fractures of the face indicate significant impact.

1. Blunt Force Trauma
Matthew Porcelli
An 420-09: Forensic Anthropology

2. What is Blunt Force Trauma?
• Blunt force trauma refers to any injury caused by
a force that has a wide area of impact on bone.
• Can effect many bones in the body and is not
just limited to head injuries.
• This type of trauma is usually accompanied by
fractures.

3. Not Just A Knock On The Head
• Blunt force trauma is not just a head injury.
• Blunt force trauma can be brought about by a
blow to the head, a plunge off of a bridge or cliff,
and as well as a train, plane, or automobile
accident.

4. Weapons of Blunt Force Trauma
• The selection of weapons used in blunt force
trauma injuries are endless.
• Some handheld instruments include:
• Crowbars, baseball bats, 2x4’s, hammers, rocks,
……..it really is an ongoing list.

5. Size, Shape, & Weight
• Size- the size of a blunt trauma weapon mainly
consists of its length and width.
• Shape- the shape of a blunt trauma weapon
refers to its cross-sectional outline and its
longitudinal configuration.
• Weight- the weight of a blunt trauma weapon
can be estimated by the resultant injury into
categories such as heavy or light.

6. SIZE
• The size of the instrument used can be difficult
to determine some of the time.
• The dimension of the object that caused the
trauma cannot really be measured on a general
scale, such as in centimeters or inches.
• Length and Width estimations are determined by
long and short axes.

7. SHAPE
The shape of an instrument used in this type of
injury will refer to its cross-sectional outline and
its longitudinal configuration.
Round and Angular are the two cross-sectional
shapes that are looked at.

8. Shape (Continued)
• Round Outlines:
• Many household tools
• Clubs
• Baseball Bats
• Glass Bottles
• Tree Branches
• Angular Outlines:
• Different types of lumber
(Ex: 2x4)
• Crowbars
• Pieces of Metal

9. WEIGHT
• The heavier the object, the more damage that it
will do.
• In collision injuries, weight of the object is
considered to be irrelevant.
• This also goes for plunges from high levels.

10. Appearance of Fractures
• Comminuted Fractures tend to be the most
frequently visible during cases of blunt force
trauma.
• A comminuted fracture consists of more than
two fragments of bone being broken off.
• The bone, in most cases, may be broken,
splintered, or crushed into many pieces.

12. Blunt Force Trauma To The Skull
• When discussing Blunt force trauma, most
people will envision an injury to the skull or the
face.
• The skull reacts differently to blunt force injuries
than long bones.
• The skull vault passes through many stages
when it is inflicted with a blunt trauma injury.

13. Inbending & Outbending
• Inbending- occurs at the point of impact.
• Outbending – occurs at the surrounding area of the impact site.
• With the aid of force, fractures lines will begin to form at
various points of the outbent surface, and then progress
inward to the impact site, and outward, where fracture
lines will be formed.
• Depending on the amount of force inflicted, may
continue outwardly, and can cause the formation of
wedge-shaped bone.

16. Blunt Force To The Face
• Blunt forces to the face are guided by three
paired areas of buttressing:
1. The Alveolar Ridge
2. The Malar Eminences
3. The Nasofrontal Processes of the Maxillae
- These three buttresses, when blunt force is
applied to the face, can result in LeFort
fractures.

17. LeFort Fractures
• LeFort fractures consists of three different
phases:
1. LeFort I- runs between the maxilliary and orbital floors.
2. LeFort II- results from a downward blow to the nasal area.
3. LeFort III- refers to significant injury to many of the soft tissue
structures along the fracture lines.
- LeFort III is the most severe of the three phases and requires
considerable force to the face.

19. Blunt Force Trauma To Long
Bones
• Blunt instruments applied to long bones will
usually deliver compression and bending without
fracture lines, but will include a complete
fracture.
• Comminuted fractures can be present, but only
with a sufficient amount of force delivered to
shatter the thick cortex of the bone.

20. Blunt Trauma & Other Bones
• These bones are extremely sensitive to blunt
force trauma injuries.
• Due to the frailty of the ribs, they are most likely
to sustain blunt force injuries, or even break, if
force is applied to the side, or to the front.

21. Blunt Trauma & Other Bones
(Continued)
• The pelvis can also sustain injuries of blunt force
trauma.
• Blunt force trauma can lead to the breaking of
the pubis and the iliac crest.
• Blunt force to the scapula can result in the
seperation of the glenoid.

22. Analyzing the Trauma
• The characteristics of blunt trauma on the
skeleton can help forensic anthropologists and
investigators try and determine the cause of the
injury.
• Most blunt force trauma injuries to the skull may
be the result of a homicide committed by an
individual.

23. Analyzing the Trauma II
• Suicides and Collisions may be difficult to
determine.
• The skeleton goes through a lot of changes
during a suicide or a collision.
• Determining the size, shape, and weight is
crucial, but tedious.