May the Force…Not Be With You!

May 4, 2015 resources

And by this we mean car crash forces. In honor of May the 4th and the Force that may be with you, we want to explore how force affects us in a car crash and the innovative safety solutions that help keep us safe.

If you’ve been in a car crash then you’ve felt the effects of Newton’s Law of Motion applied to your body and you’ve seen what it does to a vehicle. Physics class taught us that an object in motion stays in motion until an outside force causes it to stop. The faster the object moves and the quicker it stops, the more the force is magnified.  Use the basic formula of Weight x Speed = Force to calculate the approximate force felt in a 20 mph crash with a 4,000 lb vehicle. This is also the restraining force needed to keep you in the seat belt. This is just an estimate and a more complex formula is used in crash testing seat belts and child car seats.

To counter force, the best solution is to slow down the body during a collision. This helps reduce the chance of serious injuries because the more energy generated in an event, the higher the chance of injury. Not only do seat belts and air bags keep us from being ejected, they spread the crash forces over larger and stronger areas of our bodies. Doing so keeps the belt from tightening down on a single small area of the body, preventing major internal injuries.

Forces will also affect the way you can and cannot control the vehicle. If you are not wearing a seat belt during a collision, your body mass will keep you from being able to steer properly in the event you need to make a sudden turn. This may cause you to over steer and you maybe flip the vehicle.

People are often surprised that no one died when they see compacted, crashed cars. Vehicles are designed to crumple so they take the brunt of the crash forces and minimize the crash loads on the occupants. In addition to the vehicle design, seat belts and air bags play an integral role in decreasing crash forces.

When an air bag deploys, it can feel like its whacking you in the face but it is actually helping you ride down the crash. It’s also preventing the impact of a passenger with the steering wheel or front dash board. Although air bags have caused minor injuries like burns or even a broken wrist, they have saved thousands of lives since their implementation. Given the prevalence of air bags in today’s vehicles, drivers are recommended to position their hands on the steering wheel anywhere from 9 and 3 to as low as 7 and 4. Traditionally the recommended hand position was at 10 and 2, but in this position a driver’s arms can get injured or thrown back into the driver’s face if the air bag deploys.



Car seats play a key role in reducing the injury and death of children in the event of a crash. Their bodies are more delicate and need more of the crash loads spread across their body. This is why car seats have a 5-point harness and why it is important for kids to stay in the 5-point harness for as long as possible. The collar bone and pelvic bone are the strongest parts of the body so spreading the crash loads across these parts puts less force on internal organs. A 5-point harness helps the child ride down the crash. Forces are also spread throughout the car seat and that is why you see many seats designed with energy absorbing foam. The foam is another component that helps minimize the force on the child and transfers it to the car seat during a collision. A car seat that is properly installed in your vehicle, properly fits your child and used every time you drive is the best protection you can give your child.

In a Galaxy far, far away…..we seldom wore seat belts or used car seats. Today’s parents and caregivers are becoming increasingly aware of the dangers of not wearing a seat belt and the high rate of improperly installed car seats (80%)! We want you to be safe, too!