Police have difficulty wearing seat-belts “properly” due to the accessories they must wear. But there is less excuse for average citizens who are unaware of the risks.

The above photo was posted by the OPP to remind motorists that they will be on the lookout for none-use of seat-belts over the Easter weekend. The campaign is commendable as seat-belt use is so critical in determining whether someone dies, is permanently injured, or comes home with minor injuries. Unfortunately the photo itself demonstrates the reality that many police are not trained to recognize the word “properly”. There are a number of issues shown in the above photo which should raise a concern about the officer’s safety should a significant collision occur. That being said, officers must carry a number of “accessories” on their body in case they have to response to an emergency where timing of response is critical. We need to review the basics of occupant safety before focusing on what problems are visible in the above photo.

Seat-belts are very effective when they are used properly. And even when they are used improperly they still provide some benefit. The whole idea behind seat-belt effectiveness lies in the timing of an occupant’s deceleration and how that will occur. Seat-belts need to be pressed close against an occupant’s body so that the beneficial “ride down” can occur as quickly as possible. Secondly, seat-belts need to be placed across proper portions of the occupant’s body so that the forces are applied to those areas that can withstand those forces.

Before the advent of pre-tensioners many collisions occurred when seat-belts contained a great deal of slack. For example my studies commencing almost 40 years ago showed that, in a serious collision, the loading of a seat-belt occurred at a delayed time similar to a seat being positioned in the “full forward” position. This needs a little explaining. When we get in our seat we adjust it to fit our comfort and often it is not in the full forward position unless we are extremely short in stature. Without going into detail, I was able to examine the “loading marks” on seat-belts to determine their precise length at the time of a collision. This research showed that many seat-belts were not effective because there was too much “slack”. Occupants were not loading their seat-belts until they were in a position equivalent to sitting with their seat full forward. For this reason occupants were not getting the benefit of being restrained by their the seat-belts. This observation was not unique to myself but many safety researchers recognized the problem. So in modern times “pre-tensioners” were installed that, upon sensing a collision, would explode and pull the webbing of a seat-belt, usually about 4 inches, against the occupant’s body. This nullified the problem of slack in most cases. But that is not the only concern.

Not only must seat-belts work as quickly as possible, they must also be applied to the strong portions of the body that can withstand those impact forces. When seat-belts were originally introduced it was understood that placing the lap belt below the illiac crests of the pelvis was desirable. These bones are located below the abdomen. But if the webbing is placed just above those illiac crests bad stuff happens. What the general public does not understand is that, above the illiac crests there is nothing but vulnerable soft tissue all the way back to the spine. Such soft issue cannot accept typical collision loads. So proper vertical placement of the lap belt becomes crucially important, even though pre-tensioners may exist. This is even more important for children approaching adult stature where such proper placement becomes more difficult. So seat-belt effectiveness depends on where the webbing is pressed onto the occupant’s body.

For torso (shoulder) belts similar concerns apply. The webbing must load the collar bone (clavicle) region. Placing the webbing in any other orientation can be dangerous if not deadly. So placing the webbing underneath an arm, for example, will cause the load to be applied below the arm pit and across the ribs. This application can cause rib fractures as well as injuries to the lungs, heart etc, which should be understood as very dangerous.

So, to summarize, seat-belt effectiveness is not dependent on whether you snap the belt on or not. This is the problem with current propaganda with seat-belt campaigns. Seat-belt effectiveness is dependent on early deceleration and proper positioning. Both of these require the occupant’s attention before starting any vehicle.

Now, returning to the photo posted by the OPP. There are an number of concerns about the placement of the lap shoulder (torso) webbings in this photo. Pretty well all of these concerns relate to the accessories worn by the officer, accessories that the average citizen should not have to deal with. To some degree the lap belt is positioned somewhat low below the pouches worn on the belt buckle. It could be worn in a worse position if the lap belt was above those accessories. But we have to think what would happen in a serious collision when the lap belt is pulled tight by a pre-tensioner and the lap webbing begins to apply a force on the officer’s body. While the belt may be relatively low it will be pressing on the accessories attached to the officer’s belt buckle. The load which would normally pass, unobstructed onto the illiac crests will now be passed through those accessories that are located at a higher position and onto the officer’s abdomen.

A similar concern is visible for the officer’s shoulder belt which is pressing against his radio. Again, the torso webbing must apply a load onto the collar bone area not to the centre of the chest. The narrowed dimensions of the radio will concentrate the force on that accessory and the force will be applied onto the chest behind that radio. This is not a helpful outcome.

So while police are busy telling regular citizens to wear their seat-belts they do not tell those citizens that wearing a seat-belt is insufficient for their safety. Citizens, like police, need to understand that the word “properly” is just as important as the word “wear”. Not only must you wear your seat-belt but you must ensure that it is in a proper position and orientation so that it protect you from harm.