The effect of a helmet on head injury

Wearing a helmet considerably reduces the risk of head injury in a crash. In the early 1980′s researchers Huijbers and Van Kampen estimated the effect of wearing a helmet: the risk of being killed was 40% lower and that of severe injury went down with 30%.

More recent studies confirm this positive effect. For example, an Italian study among scooter riders from 2003 showed that after helmet use was made compulsory, the risk of head trauma was three to four times smaller. A WHO study from 2006 states that the risk of head injury and its severity is 72% less when wearing a helmet.

This, obviously, requires the helmet to be worn correctly.

Types of helmets

There are mainly three types of helmets today:

1. the integral helmet: this is a helmet that completely encloses the entire head and is equipped with a fixed jaw guard.
2. the jet helmet; this helmet does not have a jaw guard but only a usually hinged visor in front.
3. the system helmet; this is an integral helmet with a hinged jaw guard.

Studies have been carried out of any differences in effectiveness between the various helmet types, particularly the integral helmet and the jet helmet. It is clear that an integral helmet with a fixed jaw guard considerably reduces the risk of chin and facial injury. The jet helmet lacks this protection. This should be considered when choosing a helmet.

Does helmet color matter? According to a study by Wells et al. (2004), the color of the helmet can be important in preventing crashes. Wearers of a white helmet even have a 24% lower crash rate than those wearing a black helmet. The increased visibility makes motorcycle riders easy to spot by other trafficants.

For more information see information from the Dutch Institute for road safety research, SWOV.

The three collisions in a crash

When a crash occurs, a car occupant without a seat-belt will continue to move at the same speed at which the vehicle was travelling before the collision and will be catapulted forward into the structure of the vehicle – most likely into the steering wheel if they are driving, or into the back of the front seats if they are rear seat passengers.

There are three collisions that occur in every crash where a person isn’t wearing a seat-belt. The first collision involves the vehicle and another object, e.g. another vehicle, tree, signpost, ditch or or animal. The second collision occurs between the unbelted person and the vehicle interior, e.g. the driver hits his chest on the steering wheel or his head on the window. Finally, the third collision occurs when the internal organs of the body hit the chest wall or the skeleton. It is the second collision that is most responsible for injuries, and can be reduced significantly by the use of seat-belts and child restraints. The most serious injuries in a car crash are to the head, followed by the chest and the abdomen.

Seat-belts to the rescue

The use of seat-belts and child restraints is one of the most important actions that can be taken to prevent serious injury in a car  crash. While seat-belts and child restraints do not prevent crashes from taking place, they play a major role in reducing the severity of injury to vehicle occupants involved in a collision. An occupant’s chance of survival increases dramatically when appropriately restrained.

Since the 1960s studies  throughout the world have shown that seat-belts save lives.  A review of research on the effectiveness of seat-belts found that their use reduces the probability of being killed by 40–50% for drivers and front seat passengers and by about 25% for passengers in rear seats. The impact on serious injuries is almost as great, while the effect on slight injuries is smaller at 20–30%.

Here is one video that explains the danger and risk of serious injury if you are using a forward-facing child restraint: