PHTLS Kinematics of Trauma 4

Question 1

A motorcyclist traveling at 55 mph strikes a guardrail and is ejected. Which injury pattern should be the highest priority concern based on kinematics?

Accepted Answer

Multisystem trauma including head, thorax, and abdomen

Answer

Ejection from a motorcycle at highway speed subjects the rider to multiple high-energy impacts, making multisystem trauma the expected injury pattern.

Question 2

In a frontal vehicle collision, the 'down-and-under' pathway most commonly results in which injuries?

Accepted Answer

Knee, femur, and hip injuries from dashboard impact

Answer

The down-and-under pathway drives the knees into the dashboard, transmitting force up through the femur and into the hip joint.

Question 3

A 250-lb patient and a 125-lb patient are both involved in identical crashes at 40 mph. Which statement best describes the energy involved?

Accepted Answer

The heavier patient has twice the kinetic energy

Answer

Kinetic energy equals ½mv², so doubling the mass doubles the kinetic energy when velocity is held constant.

Question 4

Which anatomical region is at greatest risk during a lateral (T-bone) vehicle collision on the driver's side?

Accepted Answer

Ipsilateral clavicle, ribs, pelvis, and head

Answer

A lateral impact directly compresses the side of the vehicle into the driver, causing ipsilateral clavicle, rib, pelvic, and head injuries.

Question 5

A patient was struck by a vehicle while walking. The paramedic notes the bumper height corresponds to the patient's mid-thigh. What is the FIRST injury expected in the classic pedestrian-vs-vehicle pattern?

Accepted Answer

Femur/tibia fracture at bumper level

Answer

The initial impact of the bumper against the lower extremity at bumper height is the first of three phases in a pedestrian collision.

PHTLS - Prehospital Trauma Life Support Practice Test

PHTLS - Prehospital Trauma Life Support Practice Test

PHTLS Kinematics of Trauma 4