Emergency Medical Technician (EMT) Basic Certification Practice Exam

Which areas are most commonly affected by crash injuries when a patient experiences a down and under pattern?

1. Knees, femurs, hips, pelvis, spine

2. Head, shoulders, arms, legs, feet

3. Hands, wrists, elbows, neck, lower back

4. Chest, abdomen, thighs, calves, ankles

The correct answer is: Knees, femurs, hips, pelvis, spine

The down and under pattern in automotive crash dynamics describes the trajectory of a patient's body during a collision, specifically when the person moves downwards and forward as the vehicle decelerates rapidly. During this motion, the lower extremities are often propelled toward the dashboard or the floor of the vehicle, leading to injuries in areas that are in direct path of impact. The areas most commonly affected include the knees, which may strike the dashboard; the femurs and hips, which can be compromised by flexing or bending forces; the pelvis, which can take on significant stress during deceleration; and the spine, which can be affected due to the abrupt motion that can cause compression or strain. This pattern often results in musculoskeletal injuries in these regions due to both the impact and the forces exerted on the body during the crash. In contrast, other options pertain to areas that may sustain injuries under different dynamics or collision patterns. For example, the head and shoulders are more likely to be injuries sustained from an impact when the body moves forward and strikes another object, rather than being positioned down and under. Thus, the specific mechanics of the down and under motion make the first option the most applicable.