Force Related Trauma

Question 1

What is force?

Answer 1

The thing that sets an object in motion

Question 2

Formula for force

Answer 2

F = ma

Question 3

What is kinetic energy?

Answer 3

The energy an object has because it is in motion

Question 4

Formula for kinetic energy

Answer 4

KE = 1/2mv^2

Question 5

What happens when motion is interrupted?

Answer 5

Kinetic energy is transferred

Question 6

Which has a bigger contribution to KE, speed or mass?

Answer 6

Speed

Question 7

What are the types of force in the forensic context?

Answer 7

Blunt force
Sharp force
Ballistic and projectile force
Combinations:
Crush forces (chopping)
Concussive forces (explosive)

Question 8

What is a blunt object?

Answer 8

Any wide, dull object or surface without sharp edges.

Question 9

What is blunt force?

Answer 9

Force resulting in:
a blunt object or surface striking a body
a body striking a blunt object or surface
collision between moving surface/object and a moving body
body trapped between two surfaces

Question 10

What is a sharp object?

Answer 10

An object with a sharp edge or extremity

Question 11

What is a sharp force?

Answer 11

Any force delivered via a sharp object resulting in:
wound with cleanly divided edges
may involve more than one tissue (same contact)

Question 12

Give examples of sharp objects

Answer 12

Knives
Axe
Scalpel
Glass
Metal shards

Question 13

What is a projectile?

Answer 13

Any object propelled by the application of force that then moves freely under only the force of gravity

Question 14

What is projectile trauma?

Answer 14

Any trauma resulting from the contract of a projectile with a body

Question 15

What is ballistic trauma?

Answer 15

Any trauma resulting from the contact of a bullet or missile with a body; AKA gunshot wound

Question 16

What are the three types of projectiles? Describe their velocity.

Answer 16

Bullets/missiles - high
Shrapnel - low through high
Arros/arrow heads - low/medium

Question 17

What is concussive force?

Answer 17

Destructive wave of compressed air propelled outward from an explosion

Question 18

What is an explosion?

Answer 18

Massive, fast release of energy

Question 19

What types of energy are involved in concussive force?

Answer 19

Blunt energy (conventional weapons)
Heat energy
Radiation energy (nuclear weapons)

Question 20

What type of forces combine to make concussive force?

Answer 20

Blunt (waves of compressed air) and sharp (shrapnel)

Question 21

What type of forces combine to form chop forces?

Answer 21

Blunt (weight of object) and sharp (blade)

Question 22

What type of injuries can result from force?

Answer 22

Penetrating and non-penetrating

Question 23

What is a penetrating injury?

Answer 23

Pierce tissue and enter the body or organs

Question 24

Give examples of penetrating injuries

Answer 24

Stab wound
Blunt force trauma causing a rib fracture that punctures the lung

Question 25

What are non-penetrating injuries?

Answer 25

Affect body tissues without piercing them

Question 26

What are the 7 categories of traumatic injuries?

Answer 26

Abrasions (scrapes)
Contusions (bruises)
Lacerations (tears)
Incisions (cuts and stabs)
Crush injuries (can be mixed)
Tissue destruction
Fractures

Question 27

Which of the seven categories of traumatic injuries can be caused by blunt force?

Answer 27

Contusions
Fractures
Lacerations
Abrasions (friction)

Question 28

What is the most common mild traumatic brain injury?

Answer 28

Concussion

Question 29

What causes concussions?

Answer 29

Rapid decelerations

Question 30

What can cause rapid deceleration resulting in a concussion?

Answer 30

Collision and/or coup/countercoup injury (blunt force trauma)
Sudden stop (without blunt force trauma)
Rapid rotation (fall)

Question 31

Describe a coup injury

Answer 31

Caused when head stops suddenly
Brain rushes forward
Injured by:
hitting inside skull
rubbing against inner ridges

Question 32

Describe a contre coup injury.

Answer 32

Brain bounces off primary surface and impacts against opposing side of skull.
Additional injury from brain rubbing against inner ridges

Question 33

What type of causes basilar skull fracture?

Answer 33

High velocity blunt force trauma

Question 34

How prevalent are basilar skull fractures?

Answer 34

~20% of all skull fractures

Question 35

What are basilar skull fractures correlated to?

Answer 35

High-risk behaviour
Example: MVA, assault, ballistic trauma (rarely)

Question 36

What can lead to death as a result of basilar skull fractures?

Answer 36

major vessel damage

Question 37

What are symptoms of anterior cranial fossa fractures?

Answer 37

Periorbital damage
Visual disturbance
Loss of feeling to forehead
Rhinorrhea

Question 38

What are symptoms of middle cranial fossa fractures?

Answer 38

Otorrhea
Loss of sensation to lower face

Question 39

What are symptoms of posterior cranial fossa fractures?

Answer 39

Battle sign, loss of gag reflex

Question 40

What are the 4 types of sharp force injuries

Answer 40

Incisions
Stab
Fractures
PuncturesD

Question 41

Differentiate between incisions and stabs

Answer 41

I: longer than deep
S: deeper than long

Question 42

What are the 4 types of projectile injuries?

Answer 42

Incisions
Contusions
Fractures
Punctures

Question 43

What is a cavitation injury?

Answer 43

Object creates a concentrated spiral of pressure that pushes tissue away from the piercing.

Question 44

Differentiate between primary and secondary ballistic injuries in the brain.

Answer 44

Primary: due to tissue destruction
Secondary: due to sequellae of the primary injury

Question 45

Describe the pathophysiology of primary brain injuries

Answer 45

Tissue deformation, axonal shearing, contusion, necrosis, blood-brain barrier disruption

Question 46

Describe the pathophysiology of secondary brain injuries

Answer 46

Cerebral edema
Increase in inflammatory cytokines
Mitochondrial damage
Excitotoxicity
Ischemia