Forensic Aspects of Trauma

Question 1

What is an injury?

Answer 1

Damage to any part of the body due to the applicationof mechanical force

Question 2

What are blunt force injuries?

Answer 2

Damage caused by impact with a blunt object e.g ground, fist, foot, weapon

Question 3

What are the types of injuries you get after a blunt force injury?

Answer 3

Contusions (bruises) - burst blood vessels in skin.

Abrasions - scraping of skin surface.

Lacerations- cut or tear of skin due to crushing.

Question 4

How are injuries classified?

Answer 4

Appearance or method of causation.
Manner of causation e.g suicidal, accidental etc.
Nature of injury - blunt force, sharp force, explosive

Question 5

What is the equation for kinetic energy?

Answer 5

Kinetic energy = 1/2 mass x velocity squared.

Question 6

How does area over which the force acts affect the strength of injury?

Answer 6

Damage to a tissue is much greater if a smaller area is used as the same force driven through a small area.

Question 7

What can excessive mechanical force cause?

Answer 7

Compression
Traction
Torsion
Tangential (shearing)

Question 8

What are some factors that affect the prominence of bruises?

Answer 8

Skin pigmentation.
Depth and location - occur more readily over loose skin.
Fat - increased subcutaneous fat means you bruise more easily.
Age- elderly and children.
Resilient areas - bottom, abdomen
Coagulative disorders - thrombocytopenia, Von Willebrand disease, alcoholics, liver disease etc

Question 9

What are some patterns of abrasions?

Answer 9

Serrated blades.
Bite marks.
Manual strangulation

Question 10

What are sharp force injuries?

Answer 10

Injury caused by any weapon with a sharp cutting edge. They can be superficial or penetrating

Question 11

What is an incised wound?

Answer 11

Superficial sharp force injury caused by slashing motion. They are longer on surface than they are deep.

Question 12

What is a stab wound?

Answer 12

Penetrating injury resulting from thrusting motion. They are deeper than they are long on surface

Question 13

What is a passive defensive type injury?

Answer 13

Victim raises arms/legs for protection. Sliced, shelved often with skin flaps over backs of hands and forearms

Question 14

What is an active defensive injury?

Answer 14

Victim tries to grab weapon or attackers hand. Sliced, shelved incised wounds on Palmer aspect of hands and web spaces between fingers- particularly between thumb and index finger

Question 15

How do self inflicted injuries present?

Answer 15

Commonly sharp force.
Usually on wrists, forearms, chest and abdomen.
They are commonly parallel, multiple and tentative incisions

Question 16

What is meant by a tentative incision?

Answer 16

Mixture of superficial abrasions and deeper cuts. Indicates they were either plucking up the courage or testing out what strength is needed.

Question 17

What is diffuse axonal injury?

Answer 17

Clinical term for immediate and prolonged coma with no apparent mass lesion or metabolic abnormality

Question 18

What is Traumatic axonal injury?

Answer 18

Pathological term for damaged axons due to trauma.

They can be focal or diffuse and are graded 1-3 depending on severity

Question 19

What is commotion cordis?

Answer 19

Stunning of the heart due to massive impact against the chest