EMS & MedicalAKA: Injury mechanism, Trauma mechanism

Mechanism of Injury

Mechanism of Injury (MOI) is the environmental method and physical force distribution — such as fall height, vehicle rollover, ejection, speed, or blunt impact location — that caused traumatic injury …

Definition & Operational Usage of Mechanism of Injury

What Is Mechanism of Injury?

Mechanism of Injury (MOI) is the environmental method and physical force distribution — such as fall height, vehicle rollover, ejection, speed, or blunt impact location — that caused traumatic injury to a patient.

⚠️ Operational Safety Warning:Never rule out severe internal injuries based solely on a normal initial physical exam if the mechanism of injury was high energy.

Why Mechanism of Injury Matters on the Fireground

MOI serves as an early triage filter under CDC Field Triage Guidelines. Identifying a high-risk MOI (e.g., fall > 20 feet, passenger compartment intrusion > 12 inches) triggers direct transport to a Level 1 Trauma Center even before vital signs drop.

Relevant NFPA Standards

  • NREMT Standards: National Registry of Emergency Medical Technicians Practice Standards
  • NFPA 455: Standard for Emergency Medical Services (EMS)

Field Procedures & Tactical Steps

  1. Observe physical scene cues upon arrival (windshield starring, steering wheel deformation, fall height).
  2. Gather MOI details from patient, bystanders, or law enforcement.
  3. Compare MOI against CDC Field Triage Decision Scheme criteria for trauma center transport.
  4. Correlate MOI with expected anatomical injury patterns (e.g., lap belt mark = small bowel rupture).
  5. Report detailed MOI factors during trauma center pre-notification radio report.

Common Context & Application

Evaluated during initial scene size-up on all trauma, MVC, industrial accident, and fall calls.

Frequently Asked Questions about Mechanism of Injury

What fall height is classified as a severe MOI for adults under CDC guidelines?
A fall greater than 20 feet (6 meters), or two stories, is classified as a high-risk mechanism requiring trauma center transport for adult patients.
Why is passenger compartment intrusion significant in car crashes?
Intrusion > 12 inches at the occupant site (or > 18 inches anywhere in the cabin) correlates strongly with internal organ lacerations and pelvic fractures.

Other Names for Mechanism of Injury

Injury mechanismTrauma mechanism

Mechanism of Injury may also appear in training materials, NFPA standards, or department SOPs as: Injury mechanism, Trauma mechanism.

Relevant Tools

Operational calculators related to Mechanism of Injury:

Category:EMS & Medical — Patient care, assessment, interventions, triage, and EMS system terms commonly used by firefighter/medics.
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