Kinematics Flashcards
What is Kinematics important?
- Force of acceleration/deceleration of car is equal to the speed of person
- Assessment and management of trauma patients MUST consider the kinematics/mechanism of injury as this can inform you as to potential injury patterns
- Need to assess where each person was before the crash
Common Causes of Blunt Trauma
- Low level falls
- RTCs
- Falls from height
- Crushes
- Sporting accidents
Factors Affecting Severity of Blunt Trauma
- Decelerating fast eg car to tree
- Objects projected in car
- Direction of impact
- Parts of body which absorb the energy
- Velocity at impact
- Protective eqipment
Different Vehicle Mechanism’s
- Rollover
- Frontal Impact (Down and Under, Up and Over)
- Lateral Impact
- Motorcycle Mechanism
- Car vs Pedestrian
- Rear Impact
Mechanisms that happen during a Rollover
- Roof intrusion
- Complete ejection
- Partial ejection
- Projection into objects
(5 fold increase of mortality if ejected)
Evidence in Car seen in a Frontal Impact
- Bent steering wheel
- Knee Imprint on dashboard
- Bull’s eye fracture, windscreen
Suspected Injury Pattern from Frontal Impact
- Cervical spine fracture
- Anterior flail chest
- Myocardial contusion
- Pneumothorax
- Traumatic aortic distruption
- Fractured spleen or liver
- Posterior fracture/dislocation of hip, knee
What happens in the Down and Under Mechanism?
- Force is transmitted to lower extremeties
- Upper body rotates forward and hits dash/steering wheel
What happens in an Up and Over Mechanism?
- Happens when person not wearing seatbelt in a frontal impact
- Compression on the C-Spine
- Compression of hollow/solid organs
- Chest/abdominal steering wheel
- Sheering wounds (occur when forces are applied to body tissues or parts that cause these tissues to move in opposite directions)
In a Lateral Impact, where are the 3 point of Impact?
Ribs, clavicle, humerus/arm
Suspected Injury Pattern from a Lateral Impact
- Contralateral neck sprain
- Cervical spine fracture
- Lateral flail chest
- Pneumothorax
- Traumatic aortic disruption
- Diaphragmatic rupture
- Fractured ribs assc w/ spleen/liver depending on side of impact
- Fractured pelvis or acetabulum
What happen in a Motorcycle Mechanism
- During a sudden stop, the person is most likely to go over the bar
- Riders will hit their pelvis on the fuel tank causing trauma
- The centre of gravity is behind and above the front axle
- Riders can get primary and secondary injuries
Common Motorcycle Injuries
- Bilateral wrist fractures common injury, also femur injury
- Can cause decompression of c spine, can cause sheering injuries
- Secondary injuries (head, road rash)
Car Vs Pedestrian; What happens to Adults compared to Children
- Type of vehicle will depend on mechanism of patient eg bounce off, up and over, side across (see image on slide)
- Child - will bounce off vehicle or get dragged underneath the car depending on height compared to car (check)
Car vs Pedestrian Injury Pattern
- Head injury
- Traumatic aortic distruption
- Abdominal visceral injuries
- Fractured lower extremities/pelvis
Rear Impact Injury Pattern
- Cervical spine injury
- Soft tissue injury to neck
Mechanism fo Fall from Height
- Velocity increases with height
- Landing surface affects deceleration Eg sand vs concrete
- Compression of c spine
- If patient lands feet first energy will travel from the ground up causing injuries; ankle fractures, mid shaft femur fracture, pelvic fractures and injuries sustained from secondary impact
- If patient falls flat, injuries will be dissipated and more likely to have massive internal haemorrhage
Primary Blast Injury
Blast Wave - blast lung, perforated ear drum, organ rupture, eye rupture, traumatic brain injury (causes a lot of very quick death)
Secondary Blast Injury
Penetrating - ballistic or fragmentation from bomb carrying secondary objects
Tertiary Blast Injury
Blast Wind - blunt force injuries from being thrown
Quaternary Blast Injury
Heat/Fumes - Flash burns, inhalation injuries
Quinary Blast Injuries
Dirty Bombs - bacteria, radiation, chemicals
Low Velocity Mechanism
- If the there’s a larger frontal area = more tissue dmg
- Think about fragmentation
- Tumble
- Profile of projectile
Bullet - High Velocity Mechanism
- Can create temporary cavities internally then permanent cavaties
- Can fragment, slowing the bullet down
- Severity related to the damage caused by the path of the bullet and the amount of kinetic energy that is transferred from the round to the tissues
- Bullets are designed to cause death by haemorrhage
