Vol.4-Ch.2 "Mechanism of Injury" Flashcards
What are the 2 fundamental causes of trauma?
Impacts and collisions
Kinetics is ?
Branch of physics dealing with objects in motion and energy exchanges that occur as these objects collide
Kinematics is ?
Branch of physics that studies the motion of a body or system of bodies WITHOUT consideration given to its mass or the acting forces
What are the 2 basic principals to kinetics?
Law of Inertia
Law of Energy Conservation
The law of Inertia is Newtons ____ Law?
First
The first part of Newtons Law of Inertia is?
“A body in MOTION will remain in motion unless acted upon by an outside force”
The second part of Newtons Law of Inertia is?
“A body at REST will remain at rest unless acted upon by an outside force”
What is Energy defined as?
What is the Law of Energy? (Energy Conservation)
Energy = the ability to do work
“Energy can be neither created nor destroyed. It can only be changes from one form to another”
What is Newtons second Law of Motion about?
How is it calculated?
Force = (Mass x Acceleration (or Decceleration)) / 2
What is Kinetic Energy?
How is is calculated?
Kinetic Energy = (Mass x Velocity^2) / 2
What is the definition of “kinetics of impact”?
The study of energy exchange with human body and the effects applied to the body (not only the damages on the body like “biomechanics of trauma”)
What is the definition of “biomechanics of trauma”
The manner of which the energy exchange damages the human body tissues.
What are the 3 Laws of physics used in biomechanics of trauma?
- Inertia
- Force
- Energy Conservation
What are the 3 types of forces that can damage the body when applied?
- Compression
- Stretch
- Shear
What is a compression injury?
Injury that occurs from impact that abruptly stops a portion of the body while inertia causes the reaming structures to continue in motion
What is a stretch injury?
Injury that occurs from part of the body being pulled away abruptly, specifically from tissues stretching too far
What is a shear injury?
Injury occurring along the edges of the impacting force or at organ attachments
(bascically the closest two points of partial tissue being stopped, while the other wants to keep moving because of inertia)
What are the 5 events that occur in a vehicle collision and when does each one start?
- Vehicle Collision - when the vehicle hits something
- Body Collision - when the body his the vehicle
- Organ Collision - when organs hit the inside of body
- Secondary Collision - any other loose objects that hit Pt in the vehicle
- Additional Impacts - when the vehicles gets struck again after the first impact
What is the correct way for a child safety seat to be positioned in a vehicle (under and above 2 years)
If under 2 years old (infant/small child):
Put in back seat facing backwards, held securely to seat with lap belt or lower anchors/tethers
If older than 2:
Place in back seat, facing forward, with the lab belt now going over the child at waist with 4 point restraint system holding kid in place
What are the 4 types of restraints in a vehicle?
- Seat belts
- Supplemental Restraint System (SRS)
- Child Safety Seats
- Head rests
What are the 5 types of auto impact?
- Frontal (most common)
- Lateral
- Oblique
- Rear-end
- Rollover
Frontal Impact, the most common, can cause what 4 types of pathways for a Pt?
- Restrained Pathway
- Up and Over Pathway
- Down and Under Pathway
- Ejection
In the frontal impact’s Restrained pathway, what can occur?
This implies that the lap belt and shoulder straps were used properly.
If lap belt not used: intraabdominal injury, lumbar spine injury, or hip dislocation are possible
If shoulder strap not used: contusions and rib fractures are possible
In the frontal impact’s Up and Over pathway, what can occur?
What is Axial Loading? When does it occur here?
W/out use of restraints, the body moves upward and forward (typically when Pt stiffens legs before impact); MOST DEATHS occur in the Up and Over Pathway
The legs usually get impinged on the steering wheel causing possible fractures of both femurs
The abdomen and or low chest strike the steering wheel causing possible hollow organ damage, liver laceration, if diaphragm is torn then organs can enter the wrong cavities, thoracic spine damage.
The head will trike the windshield causing AXIAL LOADING (compression force on the cervical spine) as trying to push through the windshield