1. Kinematics of Trauma

2. Learning Objectives Define energy in the context of injury production.
Describe relationship of injury and energy exchange.
List phases of assessment and their characteristics
Describe the mechanical principles of trauma
Identify types of injuries and their kinematics

3. Kinematics of Trauma
It can help explain the type of injury, outcomes and injury combinations.
It indicates the need for additional diagnostic workup and reassessment.
It is related to the type of injuring force and subsequent tissue response.
The effect of injury depends on personal and environmental factors.
Crash: is the energy exchange that occurs when an energy force (usually solid object) impacts the human body.

4. Phases of Assessment and Management
Precrash phase: include the events that precede the incident
E.g.: alcohol ingestion, past Hx, drugs,

5. Phases of Assessment and Management
Crash phase: begins at time of impact between one moving object and a second object.
Considerations include:
The direction of energy exchange
The amount of energy exchanged
The effect of force on the patient

6. Phases of Assessment and Management
Postcrash phase: begins as soon as energy from crash is absorbed.
Information gathered about crash and precrash is used to manage patient.

7. General Principles
To understand the effects of force on body it is important to understand two components (Energy and Anatomy)
Laws of Energy and Motion:
Newton’s first law of motion
Conservation of energy
Force = mass x acceleration (deceleration)

8. Factors Affecting Energy Exchange between Solid Object and Human Body
Tissue Density
Air filled organs
Fluid filled organs
Solid organs
Contact area
Cavitation

9. Mechanical Principles
Blunt Trauma
Penetrating Trauma

10. Blunt Trauma
Forces involved are shear (changing speed) and compression (squeezing).
Multiple injuries are common with blunt trauma
They are more life threatening than penetrating injuries
It includes MVCs, falls, assaults and contact sports, blast injuries

11. Types of MVCs Frontal impact Rear impact Lateral impact
Rotational impact
Rollover

13. Phases of pedestrian injuries
The initial impact to the legs and sometimes the hips.
The torso onto the hood of the vehicle.
The victims falls off the vehicle and onto the ground, usually head first, with possible cervical spine trauma.

15. Falls kinematics assessment
An estimation of height of the fall
The surface on which the victim landed (compressibility)
Part of body struck first

16. Sports injuries Mechanisms associated are too numerous
General principles are the same as for MVCs

17. Blast injuries
Primary injuries: caused by the pressure wave of the blast
Secondary injuries (fragmentation)
Tertiary injury: caused by hitting with object or object propelled by explosion.

18. Penetrating Trauma
Injury produced by foreign object penetrating the tissue
Penetrating objects are:
Low Energy Weapons i.e. knife
High Energy Weapons i.e. firearms
Severity of injury is related to the structure damaged
Mostly contaminated

19. Factors Affecting Severity of Penetrating Injury
Profile: initial size of penetrating object.
Tumble: angle or direction of entry
Fragmentation