MOI stands for

• A. Mechanism of Injury
• B. Nature of Illness
• C. Scene Size-Up
• D. Additional Resources

Answer: (A)

Understanding Mechanism of Injury helps you connect what happened to the injuries you might find. The mechanism is the event that caused the injuries—like a high-speed car crash, a fall from a height, or a penetrating stab wound. Knowing how the injury occurred guides you in what to look for, what to suspect, and how to treat or protect the patient. For example, a high-energy crash raises concern for spinal injuries or internal damage, so you’ll assess accordingly and use precautions like immobilization when indicated.

Nature of Illness describes medical problems not necessarily linked to an injury event, such as a heart attack or asthma attack, so it doesn’t focus on how the trauma happened. Scene Size-Up is about safety and scene conditions—hazards, number of patients, and resources—and isn’t about what caused the injuries. Additional Resources is about contacting extra help or gear, not the cause of the injuries.