Forensic Aspects of Trauma 1

Question 1

Define injury

Answer 1

Physical harm or damage to someone’s body by accident or as an attack

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

Question 2

Kinetic force = ?

What is the clinical application of this?

Answer 2

1/2mass x velocity^2

Means 1kg brick held against scalp causes no damage, but the same brick thrown at the scalp will smash the skull

Question 3

Apart from velocity of force what is the other most important factor in determining the injury caused?

Answer 3

Area over which the force acts

Smaller area = more concentration of force = more damage

Question 4

Excessive mechanical force can cause what 4 things?

Answer 4

Compression (squashing)
Torsion (twisting)
Traction (pulling apart)
Tangenital (shearing)

Question 5

What are the classifications of injury?

Answer 5

Appearance or method of causation
Manner of causation
Nature of injury

Question 6

What are the different appearances or methods of causations?

Answer 6

Abrasion, contusion, laceration, stab wound, incised wound, gunshot, burns

Question 7

What are the different manners of causation?

Answer 7

Suicidal, homicidal, accidental, self-inflicted

Question 8

What are the different natures of injury?

Answer 8

Blunt force, sharp force, explosive

Question 9

What are the different blunt force injuries?

Answer 9

Contusions
Abrasions
Lacerations

Question 10

What are contusions?

Answer 10

Blue/purple areas that result from burst BVs in the skin

They turn yellow with time due to metabolism of the blood - this can help you age them

Question 11

What are examples of patterned contusions?

Answer 11

Finger tip bruising, tyre tracks, shoe marks

Question 12

What are abrasions?

Answer 12

Scratches/grazes - scrapping of the skin surface

Question 13

How can you tell the direct of insult in an abrasion?

Answer 13

Skin tag indicates direction

Question 14

What might be examples of patterned abrasions?

Answer 14

Serrated knife drawn across skin, bite marks

Question 15

What are lacerations?

Answer 15

Tearing/splitting os kin due to crushing force

Raised edges may be seen with surrounding bruising

Question 16

What are the two types of laceration?

Answer 16

Full thickness (affecting underlying fat and muscle) and partial thickness (affecting dermis)

Question 17

What are the factors affecting prominence of contusions?

Answer 17

Skin pigmentation
Depth ad location - occurs more easily over loose skin (scrotum, eyebrow)
Fat –> inc sc fat –> more bruising
Age - children’s skin looser and more delicate, elderly BV less supported
Resilient areas incl. buttock and abdo
Coagulative disorders

Question 18

Give examples of coagulative disorders that would make someone more prone to bruising

Answer 18

Thrombocytopenia, (alcoholic) liver disease, haemophilia, Von Willebrand’s disease, bone marrow disease

Question 19

What are sharp force injuries?

Answer 19

Those caused by any weapon with a sharp cutting edge

Question 20

What are the two types of sharp force injuries?

Answer 20

Incised wounds

Stab wounds

Question 21

What are incised wounds?

Answer 21

Caused by slashing motion
Wound longer than it is deep
Generally caused by knife/broken glass

Question 22

What are stab wounds?

Answer 22

Deeper than they are long

Caused by thrusting motion (generally knife)

Question 23

What are examples of patterned stab wounds?

Answer 23

Screwdrivers, scissors etc.