Road traumatology

The road traumatology is the study of the physical traumatisms resulting from the road accidents.

In many cases, in particular the accidents at high speed or the pedestrians or two-wheeled vehicles reversed, the victims suffer from many traumatisms.

Vocabulary

Imprisoned : the victim known as “is imprisoned” in a vehicle if the deformation of the vehicle causes itself a wound (for example: lower extremities compressed by the projection of the instrument panel);
trapped : a victim known as “is trapped” in a vehicle if the deformation of the vehicle prevents it from leaving, without that causing him traumatism (for example: blocked door);
polyblessé : nobody presenting several wounds, of which none endangers the vital prognosis;
polyfracturé : nobody presenting several Fracture S, of which none endangers the vital prognosis;
polytraumatisé : nobody presenting several traumatisms of which at least an endanger the vital prognosis.

Mechanism of the traumatisms

The mechanism of the accident conditions the type of attack.

Pedestrian or reversed two-wheeled vehicle

A pedestrian or a two-wheeled vehicle reversed by a vehicle can present two sources of traumatisms:

primary education traumatisms: they are the traumatisms which had with the shock between the pedestrian (or the passenger of the two-wheeled vehicle) and conveys it;
traumatisms secondary: the pedestrian (or the passenger of the two-wheeled vehicle) is projected, and the shock on the ground causes traumatisms known as “secondary”.

The damage is in general all the more important as the vehicle is fast and massive, in the order: bicycle, motor cycle (scooter), motor cycle, private car, commercial vehicle (van), weight-heavy (truck).

In the case of a pedestrian accident against private car, the mechanism of the accident will depend on the size of the pedestrian and the speed of the vehicle:

pedestrian of small size (child, or adult against 4×4): the initial shock touches the top of the body (chest, head) and the pedestrian is projected forwards;
pedestrian of big size (adult against not raised car): the initial shock touches the bottom of the body (lower extremities),

car rolling to moderate pace: the pedestrian is projected forwards;
car rolling to sharp pace: the pedestrian is mown, it rocks on the cap then is projected.

Two-wheeled vehicle alone

Not being intrinsically stable, a two-wheeled vehicle can only fall (defect of the road, loss of adherence, operates avoidance of an obstacle or a vehicle, faintness). One of course expects the usual traumatisms of the falls low height, amplified by speed, to which come to be added the traumatisms resulting from the percussion from the machine (for example the handlebar which strikes the abdomen or the neck) or from crushing by the machine.

One can also have traumatisms of the feet if those touch the ground when the machine rolls. In the case of a passenger on the luggage stand of a bicycle, the feet can be caught in the aft wheel.

Lastly, the fall of a motorized two-wheeled vehicle can involve a slip which can cause Plaie S and Brûlure S by friction, and end in a shock against an obstacle (pavement, vehicle, rembarde of safety…).

Shock before car or of weight-heavy

When a car or weight-heavy undergoes a front shock, two situations should be considered: the passenger carries or does not carry the girdles.

The traumatisms described hereafter depend of course on many parameters of which speed at the time of the shock, and do not occur all systematically.

The passenger does not carry the belt

At the time of the shock, the occupant is projected violently forwards:

its Genou X meets the instrument panel or the seat of front, causing wounds with the knees like potentially fractures of the Fémur (“bursting” in compression);
the knees being in thrust, the occupant rocks forwards; if it acts of driver, it takes wheel in Thorax (or then the inflatable Coussin with explosive Airbag whose fabric is tightened at a speed of 300 km/h), causing a thoracic traumatism;
its head runs up against the front Pare-brise (conducting or passenger) or the front seat, causing wounds with the face, a cranial Traumatism and a traumatism of the cervical Vertèbre S; if it is about a nonlaminated windshield (old models), the head can cross the windshield, breakings of causing glass of multiple wounds, in particular with the neck;
deceleration at the time of the shock, if it is important, can cause a rupture or a désinsertion of the internal bodies;
in the case of the back passenger, the percussion of the front seat will cause traumatisms on the occupant of this seat, in particular on the level of the Spinal column;
the person can undergo other shocks in the cockpit;
the person can be ejected on the roadway or the low side, and thus undergo secondary traumatisms (the mortality of an ejected victim is multiplied by ten).

The passenger carries a belt

The belt allows the coupling of the occupant with the seat. He is thus exerted a force of the belt against the passenger (it is this force which retains it), and which can cause a typical traumatism called “traumatism of belt”: burn on the way of the belt, in particular across the chest, traumatism of the Clavicle and the coasts. If a hard object is between the belt and the passenger (for example an object in the pocket, the belt passing on this object), this hard point can cause a specific traumatism.

Deceleration, if it is important, can cause a rupture or a désinsertion of the internal bodies, with Hémorragie intern, as well as a traumatism of the cervical vertebrae (inflection of the neck).

If the belt is badly regulated, or if deceleration is sufficiently important to distend the belt or to cause a rupture of the points of fastener of the seat, the front driver or passenger can strike the top of the windshield or the wheel.

In all the cases

If an object is on the back beach of the vehicle, it is projected and can cause traumatisms with the occupants.

See too

Biomechanical Accident of bicycle
Urgency

External bonds

'' geometrical Modélisation and three-dimensional mechanics of the thoracic and lumbar rachis in automobile configuration of shock '', F. Delerba, Mechanical Thesis of , Arts and Trades (ENSAM), 2001
'' Contribution to the study of the behavior of the cervical rachis subjected to a shock '', B. Frechede, Mechanical Thesis of , Arts and Trades (ENSAM), 2003
Dealt with medical and technical of polytraumatized imprisoned, an article of the site Urgence-pratique.com
articles of the General practitioner

Accident of the public highway - While waiting for Samu, the General practitioner n°2058
the medullary casualty is not a victim like the others, the General practitioner n°2115, May 4th 2001
Désincarcérer a victim, an article of the General practitioner or on the site Urgence.com

Rapport on medicine vis-a-vis the road accidents, Maurice Cara, national Académie of medicine, June 17th 2003 (file rtf, 14p)

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