Mechanism of Injury

Video 34 of 61
3 min 46 sec
English, Español
English, Español

Physical injuries run the gamut from soft tissue injuries like bruises, cuts, and burns to those involving the musculoskeletal system and/or the head, neck, and back. While injuries can vary greatly, the tools of discovery you'll use to help you assess patients will not.

When you arrive on the scene, you'll apply the mechanism of injury method to help you gain a greater understanding of what possible injuries the patient may have based, in large part, on how he or she may have sustained those injuries.

How to Apply the Mechanism of Injury Method

As always, the first thing you want to do is make sure the scene is safe and that your gloves are on. Make sure you have your rescue mask with a one-way valve handy and begin calling out to the victim.

Are you OK? Can you hear me?

If the patient is conscious and responsive, ask yourself if there are other medical emergencies that would warrant calling 911 and activating EMS? If not, continue with your assessment.

Ask yourself questions like:

  • Is the victim favoring an area or limb?
  • Is there noticeable bleeding, protruding limbs, or other injuries?
  • Is the victim demonstrating any concussion symptoms?
  • Is there an obvious cause of the injury – slippery walkway, etc.?
  • Is the victim demonstrating any airway, breathing, or circulation problems?

Warning: If the patient does begin showing signs of decreasing levels of consciousness or any problems involving breathing, airway, and/or circulation – numbness, tingling, inability to move limbs – call 911 immediately.

Introduce yourself to the victim: "Hi, my name's _____. I'm a paramedic. Do you know what happened today? Are you in any pain?"

Pro Tip #1: Ask the victim open-ended questions when you're assessing them, rather than yes and no questions. So, instead of asking, does your head hurt?, ask, do you have pain anywhere? Asking yes and no questions can often lead them down the wrong road.

During your assessment, involve family members and friends who are nearby and may have witnessed the accident. They'll also be able tell you if the victim is behaving normally or has any medical problems or allergic reactions to medications. This is even more important when dealing with injuries to children.

Pro Tip #2: Don't be too myopic. Even though the injury may seem obvious, that doesn't mean another injury isn't also lurking. Keep this in mind as you perform a full head-to-toe examination of the patient.

A Word About Soft Tissue Injuries

Soft tissues include all the layers of skin, fat, and muscles in the human body. The largest organ is the skin, as it contains three layers of its own – epidermis (outer area that protects against bacteria), dermis (deep layer that protects the nerves), and hypodermis (the deepest layer that protects blood vessels).

Soft tissue injuries are classified as closed wounds or open wounds.

A closed wound is an injury that occurs beneath the surface of the skin, meaning that the outer layer of skin is still intact. There is usually internal bleeding, even if only minimally in the form of a bruise.

An open soft tissue wound involves a break in the skin's outer layer, like a cut, and usually involves external bleeding – arterial, venous, or capillary.

Burns deserve a special distinction as a soft tissue injury and are classified as superficial, partial thickness, and full thickness.

Closed Wounds

Closed wounds occur beneath the surface of the skin and are usually the result of blunt force. The contusion can be minor, like stubbing your toe, to more serious examples of blunt force trauma, like those sustained in motor vehicle accidents.

Swelling and discoloration are normal in closed wounds as these are part of the healing process. Closed wounds become more serous when they affect the deeper layers, those that protect larger blood vessels and vital organs. Heavy internal bleeding can occur from a contusion or hematoma and when it affects those deeper layers, the signs may not be immediately noticeable.

Opened Wounds

Open wounds are those that affect the outer layer of the skin. There are six types of open wounds:

  • Abrasions – scrapes, rug burns, road rashes, etc. – abrasions are more painful due to the presence of nerve endings nearby but don't involve much bleeding as the capillaries are mostly affected.
  • Amputations – the loss of a limb – amputations are serious injuries that rely on controlling blood loss and shock.
  • Avulsions – part of skin peeled away – avulsions can be very painful, and bleeding can be heavy.
  • Crush injuries – extreme weight or force crushes a body part – crush injuries can cause great internal damage to blood vessels and vital organs.
  • Punctures – gun shot wounds, stabbing wounds, etc. – punctures are smaller wounds that typically close around the wound, thereby limiting the amount of external bleeding. However, the puncture can also result in internal bleeding.
  • Lacerations – cut from a sharp object – lacerations vary in severity depending on several factors, including the type of bleeding that the laceration has caused – arterial, venous, or capillary.