10 free EMT practice questions: Mechanism of Injury / Nature of Illness

Pelvic fracture: s are more associated with the down-and-under path involving the dashboard and lower steering wheel impact on the abdomen, not specifically a collapsed steering wheel.

Spinal cord injury: clues are more associated with rollovers, ejection, or bicycle helmet damage, not steering wheel deformity.

Burn injury: not a mechanism associated with steering wheel collapse.

An isolated injury to the head only (scalp, skull, and face): An isolated head injury is what you predict when all the energy lands at one point on the skull: a falling object, or a blunt assault. A tumbling stair fall spreads that energy across several surfaces instead. The alert-and-oriented detail is also the part that leads crews to under-triage this mechanism; a normal mental status says nothing about the ribs, pelvis, or spine you have not palpated yet.

Isolated fractures of the lower extremities only (ankles, tibias, and femurs): Isolated lower-extremity fracture is the pattern for a controlled feet-first fall from height, where force travels up the axial skeleton from the heels and produces the calcaneus, tibia, and lumbar spine injuries that go with it. A stair fall is not a controlled landing; the patient rotates and strikes with whatever leads. Lower-extremity injury is genuinely likely here, so what makes the option wrong is the word only.

Soft-tissue injuries only, without bone involvement (bruising and abrasions): Soft-tissue injury with no bone involvement describes a low-energy event, like a slip onto a flat floor from standing in a younger patient. Twelve steps carries more energy than that, and an older adult's skeleton tolerates less of it. Expecting bruising alone is how a hip, rib, or spinal fracture gets missed, because you never perform the palpation that would have found it.

External bleeding is the most reliable indicator of how serious an abdominal stab wound is: External bleeding is a fair severity gauge for a wound whose full depth you can actually see: an abrasion, a shallow laceration. A stab wound never qualifies, because the dangerous bleeding in penetrating abdominal trauma is internal: a patient can lose a large volume into the abdominal cavity while the dressing over the wound stays nearly dry, so the wound that looks quietest on the outside can belong to the sickest patient on scene.

A small entry wound makes injury to deep organs such as the liver or spleen unlikely: This is the same error dressed up as anatomy. Entry size reflects how wide the blade was, not how far it went, and a narrow blade reaches the spleen from the left upper abdomen without difficulty. A small wound is evidence about the weapon, not evidence about the organs, and it makes deep injury no less likely.

Stable vital signs indicate that urgent transport is unnecessary for abdominal stab wounds: Stable vital signs carry real weight in a low-energy, non-penetrating complaint. In penetrating trauma they lag the injury, because compensation holds the numbers steady while bleeding continues, so 'currently stable' is one frame of a movie. Transport priority in penetrating trauma is set by what the mechanism can reach, and the reassessment is what catches the change.

Thoracic spine and rib fractures from impact to the back: Incorrect. The patient landed on his buttocks, not on his back or chest. He denies back pain, and there is no mechanism for thoracic/rib injury in this scenario.

Cervical spine injury from whiplash during the fall: Incorrect. There is no head trauma, and a buttock-first impact does not cause the whiplash motion that leads to cervical spine injury.

Pelvic fracture and femur injury from the mechanism: Incorrect. While pelvic trauma is theoretically possible from any fall, the specific mechanism (landing on buttocks) and patient presentation (localized tailbone pain, no pelvic signs) point to lower spine injury as the primary concern, not pelvic/femur injury.

This is a mechanism of injury from an unwitnessed fall: Incorrect. The fall is a consequence of the underlying medical condition, not the primary injury mechanism.

This is a low-priority call because the patient is alert and speaking: Incorrect. Alert status does not determine priority; the underlying progressive weakness and altered mental status indicate serious medical emergency requiring urgent transport and evaluation.

This requires spinal motion restriction because any fall suggests cervical trauma: Incorrect. While falls do warrant spinal precautions in high-risk mechanisms, this patient fell as a secondary event after becoming ill; the primary assessment focus is the medical emergency.

The patient's complaint of hip pain is what defines this as a significant mechanism of injury: Incorrect. A specific pain complaint like hip pain is a finding worth documenting, but it is not what defines significant MOI: the mechanism itself (the intrusion) is the criterion, independent of any particular complaint.

Normal vital signs at this point rule out a significant mechanism of injury: Incorrect. Normal vital signs early on do not rule out a significant mechanism of injury; the body can compensate for a period of time even with serious underlying injury, which is exactly why significant-MOI criteria exist as a separate red flag from vital signs.

Only unrestrained occupants are classified under significant mechanism of injury criteria: Incorrect. Restraint status does not exempt an occupant from significant-MOI classification; a restrained occupant in a vehicle with this much intrusion is still classified as a significant mechanism.

Facial and cervical spine injury from contact with the windshield: A student picks this because the up-and-over path is the frontal-crash pattern most often pictured, in which the head and face strike the windshield. The question states the windshield is intact and undamaged, so no head contact occurred there.

Abdominal organ injury from contact with the steering wheel: A student picks this because striking the steering wheel is the classic frontal-crash chest and abdominal mechanism. This patient was the front-seat passenger, and there is no steering wheel in front of the passenger seat.

Lateral chest injury from contact with the door and door post: A student picks this because lateral chest injury is the injury pattern for a side impact and for a rollover against the door. The question describes a head-on impact and states that both front doors are intact and undamaged.

Head and cervical spine injury from lateral bending away from the impact: A student picks this because they picture the occupant being flung away from the side that was struck. The vehicle does rock away from the impact, but that is exactly what whips the occupant's shoulders and head toward the intruding vehicle, driving the skull against the door post or the window.

Facial and anterior chest injury from forward deceleration: A student picks this because facial and chest injury from forward deceleration is the frontal-crash pattern they have drilled most. The question describes a square side impact and states the windshield and steering wheel are undamaged, so no forward contact occurred.

Thoracic spine injury from axial loading through the seat: A student picks this because axial loading is a real spinal mechanism, from a fall onto the feet or a dive into shallow water. It requires force along the length of the spine; the question describes a horizontal side impact with the roof undamaged, so there was no vertical load.

The first driver, because doubling the weight quadruples the energy: A student picks this because they remember that the kinetic energy relationship is not even-handed, but attach the squaring to the wrong variable. Weight contributes in direct proportion, so doubling it only doubles the energy; it is speed that is squared.

Neither driver, because the doubled speed and halved weight cancel out: A student picks this because the two vehicles look like an even trade of weight for speed. It would be an even trade only if speed contributed in direct proportion, the way weight does. Doubling the speed multiplies the energy by four while halving the weight only cuts it in half, so the trade is not even.

The first driver, because more weight means more energy to absorb: A student picks this because heavier feels more dangerous, and weight really is part of the relationship. Weight matters, but it contributes in direct proportion while speed is squared, and the occupant's own energy comes from the speed the body was traveling rather than from the weight of the vehicle around it.

Wrist injury, because a falling child extends the arms to break the fall: A student picks this because catching yourself on an outstretched hand is the adult reflex, and wrist fracture is the classic adult low-fall injury. A toddler's head is proportionally much heavier than an adult's, so the head, not the hands, arrives first.

Ankle and knee injury, because the legs absorb the energy of a short fall: A student picks this because a feet-first landing does load the legs, transmitting energy through the calcaneus, the pelvis, and the spine. That applies to a patient who lands on the feet; a top-heavy toddler going over an edge does not.

Clavicle injury, because the shoulder takes the first impact in a low fall: A student picks this because clavicle fracture is a common pediatric injury and is easy to attach to any fall. It follows a fall onto the shoulder or the outstretched arm, not the head-leading fall a toddler's body proportions produce.