Kinematics of Trauma & MOI

What are the two body pathways seen in a frontal impact MVC?

Down and Under pathway and Up and Over pathway

What happens in the Down and Under pathway?

The body travels downward into the seat and forward into the dashboard or steering column

What body part becomes the leading point of impact in the Down and Under pathway?

The knees

What injuries are associated with the Down and Under pathway?

Knee dislocation, patellar fracture, femoral fracture, hip dislocation/fracture, acetabular fracture, vascular injury, and hemorrhage

What happens in the Up and Over pathway?

The body strikes the steering wheel and the ribs and underlying structures absorb momentum

What injuries are associated with the Up and Over pathway?

Rib fractures, ruptured diaphragm, hemo/pneumothorax, pulmonary contusion, cardiac contusion, tamponade, myocardial rupture, and aortic aneurysm

What should be suspected if the head strikes the windshield first in a frontal impact?

Cervical fracture from axial loading injury

What type of collision is a lateral impact?

A T-bone collision

What occurs in a lateral impact collision?

The vehicle is struck from the side

What injuries are associated with a lateral impact collision?

Clavicle, rib, and pelvis fractures

What injuries can occur in a rotational impact collision?

The same injuries seen in head-on and lateral collisions

What is the major concern in a rollover collision?

Ejection and multiple injury types

What type of injuries are common in a rear-end collision?

Back and neck injuries from hyperextension

What injuries are associated with a motorcycle head-on impact?

Head and neck trauma and compression injuries to the chest and abdomen

If a motorcyclist’s feet remain on the footrests during a head-on crash, what injuries may occur?

Mid-shaft femur fractures and perineal injuries

What occurs during an angular motorcycle impact?

The rider is caught between the motorcycle and a second object

What injuries are associated with an angular motorcycle impact?

Crush injuries, open femur/tibia/fibula fractures, and malleolus fracture/dislocation

What is road rash?

Massive abrasions from laying a motorcycle down

How should road rash be treated?

As a burn

What injuries are common when a motorcycle is laid down?

Fractures on the affected side and road rash

How do pediatric pedestrians typically face an oncoming vehicle?

They tend to face the vehicle

What is the primary impact in pediatric pedestrian collisions?

Frontal impact above the knees and pelvis

What injuries are associated with the primary impact in pediatric pedestrian collisions?

Femur and pelvic injuries with internal hemorrhage

What is the secondary impact in pediatric pedestrian collisions?

Being thrown backward with head and neck flexing forward

What is the tertiary impact in pediatric pedestrian collisions?

Being thrown downward onto the ground

How do adult pedestrians typically react to an oncoming vehicle?

They turn away from the vehicle

What is the primary impact in adult pedestrian collisions?

The bumper striking the lower legs

What injuries are associated with the primary impact in adult pedestrian collisions?

Lower leg injuries

What is the secondary impact in adult pedestrian collisions?

Impact with the hood or windshield

What injuries are associated with the secondary impact in adult pedestrian collisions?

Femur, pelvis, thorax, and spine fractures

What is the tertiary impact in adult pedestrian collisions?

Being thrown to the ground

What injuries are associated with the tertiary impact in adult pedestrian collisions?

Hip and shoulder injuries, deceleration injuries, fractures, and hemorrhage

What causes primary blast injuries?

The pressure wave from an explosion

What body systems are commonly injured in a primary blast injury?

Ears, lungs, CNS, eyes, and GI tract

What causes secondary blast injuries?

Flying debris

What injuries are associated with secondary blast injuries?

Blunt, penetrating, and lacerating injuries

What causes tertiary blast injuries?

The patient being thrown into the ground or other objects

What is cavitation?

The opening produced when a force pushes body tissues laterally away from a projectile tract

What determines the severity of ballistic injuries?

The energy created and dissipated by the projectile into surrounding tissues

What is the formula for kinetic energy?

KE = 0.5 × mass × velocity²

What happens to kinetic energy if velocity doubles?

Kinetic energy quadruples

Why can a small caliber bullet cause severe injury?

Because high velocity can create more energy than a large caliber bullet moving slowly

What is the most important factor affecting ballistic injury severity?

Velocity

What injuries should be suspected in a rollover crash?

Multiple injury patterns and possible ejection injuries

What organ injury should be suspected in a right-sided lateral impact?

Liver rupture

What organ injury should be suspected in a left-sided lateral impact?

Spleen rupture

What cardiac injuries may occur in an Up and Over frontal impact?

Cardiac contusion, tamponade, myocardial rupture, and aortic aneurysm

What thoracic injuries may occur in an Up and Over frontal impact?

Rib fractures, pulmonary contusion, hemo/pneumothorax, and ruptured diaphragm

What mechanism commonly causes hyperextension injuries?

Rear-end collisions

What mechanism commonly causes axial loading cervical injuries?

Head striking the windshield during a frontal impact MVC

What is the primary impact injury pattern in adult pedestrian strikes?

Lower extremity injuries

What is the primary impact injury pattern in pediatric pedestrian strikes?

Femur and pelvic injuries with internal hemorrhage