Blunt%20Force%20Trauma

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Blunt Force Trauma
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DEFINITION OF WOUNDS
Medical definition
Disruption of the continuity of the tissues produced by external mechanical force.
Legal definition
Breach of the full thickness of the skin
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Wounds

• Medico legal divisions of wounds
• 1- accidental
• 2- sucidal
• 3- homicidal
• 4- self inflecting

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Blunt Force Trauma

• There are Four Main Divisions of Blunt Force Type
  Injuries.
• They are
• Abrasions or scrapes scratches and grazes
• Contusions or Bruises (leakage of blood from
  vessels extravation)
• Extra outside vasa vessel
• Lacerations or Tears
• Fractures of Bone(s)

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Types of wounds
Abrasions
Incised Wounds
Lacerations
Bruises
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Types of wounds
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Blunt Trauma

• The severity of blunt trauma depends on
• Amount of force delivered
• Time over which the force is delivered
• Region struck
• Extent of body surface struck
• Nature of the Weapon

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Blunt Trauma Wounds

• If a weapon breaks on impact less energy is
  delivered to the body
• If the body moves with the blow less energy is
  delivered to the body

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Blunt Trauma Wounds

• The larger the area over which the blow is
  delivered the less severe the injury
• An object that projects from the weapon will
  deliver all of the force
• Rounded portions of the body can sustain greater
  injuries

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ABRASIONS
There are three types of Abrasions - Impact -
Patterned - Scrapes
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Abrasions

• It is the most superficial type of injuries that
  does not penetrate the full thickness of the skin
  (usually confined to the epidermis).
• Usually caused by blunt force trauma.

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Characteristics of Abrasions

• They are usually not life threatening although
  they are painful.
• They heel without scarring.
• Bleeding/Exudation is slight and leads to
  crust/scab formation.
• Might be associated with bruising and laceration

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Blunt Trauma Wounds

• Abrasions
• An injury in which there is removal of outer
  layers of tissue by compression or a sliding
  force
• Indicates EXACT site of contact or impact
• In living persons the wound will scab over and
  become dry and darken
• Postmortem the wound is yellow with a
  parchment-like appearance

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What is the Forensic Significance of Abrasions?

• Indicates violence
• Its shape gives an idea about the causal
  instrument
• Bite abrasions take the pattern of the teeth
• Site of abrasion denotes the type of crime
• Age of abrasion can be estimated so the time of
  the incident is known
• Helps in identification of the assailant as in
  bite abrasion

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Types of abrasions

• Direct vertical impact
• The force is usually applied vertically onto the
  skin and causes crushing of the epidermis.
• The causative object may stamp its shape on the
  skin.
• Examples
• Fingernail impression and bite mark, and
  marks of a vehicle radiator on a pedestrian
  victim or the pattern of a floor grid on to which
  a person has fallen.

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Types of abrasions

• Tangential impact( brush abrasions)
• Loss or scraping of the epidermis due to
  friction against a rough surface (graze) or a
  sharp surface (scratch)
• Broader surface

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This example of brush abrasions. It illustrates a
motorcycle fatality, where the victim has come in
contact with the road surface.

• Example of a brush abrasion of the abdomen by
  scraping along a rough sooted and rusty surface
  of a metal tank during a fall.

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Types of Abrasions

• Impact Abrasions
• The blunt force is perpendicular to the surface
  of the body
• Mostly seen over bony process
• Eyebrows
• Cheekbone
• Nose

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Types of Abrasions
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Blunt Trauma Wound

• Patterned Abrasions
• This occurs when the object which impacts the
  body leaves an imprint or stamp on the skin
• Be aware postmortem insect bites may resemble
  patterned abrasions

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Patterned Abrasion
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Types of abrasions

• Fingernail abrasions
• These are important because of their frequency in
  assaults especially child abuse, sexual attacks
  and strangulations
• Often associated with focal bruises.
• Fingernails abrasions are most often seen on the
  neck, face, and the upper arms and the forearm

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Fingernail Abrasions
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Blunt Trauma Wounds

• Scrapes
• A blunt objects takes off the top layers of skin
• May go as deep as the dermis
• Leakage of fluids (serosanguineous fluid)
• The area is reddish brown and forms a scab

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• Bruising and abrasions along the right side and
  on the abdomen could have come from a number of
  causes, including being dragged pushed down to
  the ground.

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Types of abrasions

• Post mortem abrasions
• Unlike post mortem bruises, artifactual abrasions
  are common.
• They may have been inflicted after death from a
  variety of causes, including dragging a corpse or
  buffering in moving water. Some post mortem
  animal injuries resemble abrasions such as insect
  bites.

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Blunt Trauma Wound

• Dating Abrasions is a complicated process
• Scab formation begins in 4-6 hrs and is usually
  complete in 18 hrs
• The skin underneath the scab begins to regenerate
  within 72 hrs
• Once the scab falls off the skin will remodel and
  become thinner after about 12 days

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• Importance of abrasions in
• forensics
• Always reflects the site of impact.
• Often indicates the causative agent.
• Often indicates the direction of impact.
• Helps in determining the time of injury.

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• Importance of abrasions in forensics
• Helps in determining the time of injury
• Fresh hyperemia, oozing serum and usually
  without bleeding.
• Up to 36 hours hyperemia and soft yellow crust
  of dried serum.
• 2-3 days dry brown scab.
• 6-7 days falling of scab leaving a red surface
  which disappears without leaving a scar within
  2-3 weeks.

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