The Knee Airbags In Your Vehicle Only Help Real-World Dummies

It turns out that knee airbags have little benefit – except possibly to dummies who don't wear seatbelts.

A new study conducted by the Insurance Institute for Highway Safety (IIHS) reveals that knee airbags found in more and more vehicles don’t actually have a demonstrated benefit to buckled passengers. That is really no big surprise since they were designed to protect dummies. Not crash test dummies. Rather, dummies that don’t fasten their safety belts. The study includes the basic summary, “…the knee airbag — has a negligible effect on injury risk and, in fact, may even increase it in some cases…”

Automakers install these airbags to help prevent unbelted passengers from injury. It makes sense if you glance at where they are located. They are not intended to simply prevent injuries to the knee, despite their name. Instead, they are designed to pop forward and keep an unbelted occupant from submarining below the dash and thus missing the protection afforded by the dash-mounted airbags. In fact, researches looking at crash test data noticed that the knee airbags actually had a correlation with increased leg injuries, including to the femur.

If you know IIHS, they are not the type to rely just on laboratory crash testing to draw conclusions. They analyze real-world data constantly. In this case, they found that knee airbags reduced the overall risk of injury in real-world crashes by half a percentage point, from 7.9 percent to 7.4 percent, which is not statically significant. So, in both laboratory crash test and real-world crash analysis, the airbags had no proven benefit.

To draw its conclusions, IIHS looked at hundreds of its own crash tests, plus the real-world crash data from 14 states. They compared injury rates between similar vehicles with and without the knee airbags. In its final conclusion, IIHS notes, “One reason some manufacturers have been installing knee airbags is to help vehicles pass federally mandated tests with unbelted dummies. It’s possible that knee airbags would help unbelted occupants in real-world crashes.” In other words, if we may set aside political correctness for a moment, “real-world dummies.”