Kinematics - you won't even know you are doing it!

04 Jul 2014

Kinematics is the study of how matter moves and interacts with its surroundings during the collision process. It is something I have taught firefighters and rescuers for the last ten years and it has proved an invaluable tool in helping to identify time critical, life threatening injuries thus allowing this information to be an integral part of your extrication plan.

Correlation
When you arrive on scene you are faced with a lot of dynamic information. This has to be processed immediately to ensure a safe working environment. How much of the information you gather is actually Kinematics? Well, believe it or not, it is probably something you have been doing for years. Have you ever arrived on scene and witnessed a car so badly damaged that you screw your face up, suck through your teeth and look at your colleagues in a negative way? Well, that is Kinematics. You are making a direct correlation between what you see and what you imagine has possibly happened to the occupant inside the vehicle, the supposed ‘Mechanism of Injury’. The key is making that correlation part of your extrication plan.

Index of Suspicion
It is all about something I call your ‘Index of Suspicion’. A side impact with a tree at 40mph (64kmph) will result in a high Index of Suspicion as we know there are no crumple zones, limited passive safety systems and the human body doesn’t actually like to move laterally. However, a much lower speed frontal impact will produce a lower Index of Suspicion as we do have crumple zones and generally better performing airbags and we are physiologically happier moving forward! At this point I could quote Newton’s first law, which is the scientific basis for Kinematics, but as you already know that I will not insult your intelligence. 

The damage to this steering wheel was caused by the chest-abdomen of the driver – A high index of suspicion I.jpg
The damage to this steering wheel was caused by the chest/abdomen of the driver – A high index of suspicion I think!

Elements your Index of Suspicion is based on
The most important message here is to look for things that will inform your Index of Suspicion, e.g.:

- Speed of impact
- Rate of deceleration
- Was a seatbelt worn?
- Did the vehicle rollover?
- Are there signs of ‘Bulls Eyes’ (head striking the windshield)?

Medical handover
Also remember that the Kinematics / Mechanism of Injury should always be communicated where there is a need to hand the patient over. A medical handover can be done in many different ways but a simple one is MIST.

Mechanism of Injury
Injuries found or suspected
Signs and symptoms
Treatment given

Conclusion
Kinematics is only ever a guide; a starting point for a patient assessment which allows you to focus your mind. Next time you train, talk about Kinematics and Mechanism of Injury; it really does shed a whole new light on how you view (and handle) your patient. Remember, your assessment has to be proportionate as this MUST WATCH video highlights ;-)

As ever, I welcome your feedback.

Ian

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