Chapter 3, Biomechanics and Mechanisms of Injury

Question 1

When does trauma occur?

Answer 1

When the intensity of the applied energy exceeds the capacity of tissue resistance.

Question 2

What kind of energy is energy at rest?

Answer 2

Potential energy.

Question 3

What kind of energy is energy in motion?

Answer 3

Kinetic energy.

Question 4

What is Newton’s First Law of Motion?

Answer 4

A body at rest will remain at rest and a body in motion will remain in motion unless acted upon by an object.

Question 5

What is Newton’s Second Law of Motion?

Answer 5

An object’s acceleration depends directly on the net force and indirectly on the mass of an object.

Force is increased = acceleration is increased
Mass is increased = acceleration is decreased

Question 6

What is Newton’s Third Law of Motion?

Answer 6

For every action there is an equal and opposite reaction resulting from the transfer of energy.

Question 7

What is the Law of Conservation of Energy?

Answer 7

Energy cannot be created or destroyed, only changed from one form to another or transferred from one object to another.

Question 8

Why is it important for the trauma nurse to understand MOI and energy transfer?

Answer 8

Prepare for evaluation and to anticipate damage.

Question 9

How do you determine the amount of KE an object has?

Answer 9

KE is equal to one-half the mass multiplied by the square of its velocity.
KE = 1/2 mv2

Question 10

In which two ways is external energy exerted?

Answer 10

Acceleration force.
Deceleration force.

Question 11

What are the different types of energy forces?

Answer 11

Tension.
Compression.
Bending.
Shear.
Torsion.
Combined loading.

Question 12

What are the two classifications of trauma related injuries?

Answer 12

Blunt trauma.
Penetrating trauma.

Question 13

Why might the severity of blunt trauma be dismissed initially?

Answer 13

Blunt trauma may often appear less obvious, with minimal to no outward signs of injury as compared with other mechanisms or types of injuries.

Question 14

What are the most common injuries with the following potential injury patterns in an MVC?
- Up and over
- Down and under
- Lateral (T-bone)
- Rotational
- Rollover

Answer 14

Up and over: head, neck, chest, and/or abdomen
Down and under: abdomen, spine, pelvis, and lower extremities
Lateral (T-bone): lateral chest, abdomen, and pelvic acetabulum
Rotational: Any combination
Rollover: Any combination

Question 15

Ejection from a vehicle greatly increases the probability of what?

Answer 15

Fatal injury.

Question 16

With a fall from what height is the mortality of the pediatric patient increased?

Answer 16

10 feet

Question 17

Pediatric falls are more associated with what type of injury?

Answer 17

Head injury (disproportionately larger)

Question 18

What is considered penetrating trauma?

Answer 18

Any foreign object that enters through the skin.

Question 19

Precise damage caused by penetrating mechanisms depends on what variables?

Answer 19

Point of impact
Velocity and speed of impact
Proximity

Question 20

Is velocity and KE positively correlated with destruction?

Answer 20

Yes

Question 21

What is cavitation?

Answer 21

The cavity produced when a projectile passes through tissue. May be temporary or permanent. May be caused by blunt and penetrating trauma.

Question 22

Describe the 5 effects of blast trauma.

Answer 22

Primary: Tissue damage from blast overpressure
Secondary: Wounds from primary and secondary fragments
Tertiary: Results from being thrown by the blast wind
Quaternary: Other explosion related injuries, illness, or diseases
Quinary: Illness associated with hazmat from radioactive, biological, or chemical components of blast

Question 23

Why does an explosion that occurs in an enclosed space potentially increase injury severity?

Answer 23

It has increased pressure.