A recent study conducted by the Insurance Institute for Highway Safety (IIHS) has revealed that not only knee airbags have a negligible effect on injury risk, but in some cases, may even increase it.
The Insurance Institute for Highway Safety (IIHS), a US-based non-profit organisation, conducted a study on the effectiveness of a new type of an airbag, which is gaining popularity worldwide - the knee airbag. For those not aware, a knee airbag (as shown in the image) deploys below the lower dashboard and is aimed at reducing leg injuries. In some cases, it also protects the lower abdomen by controlling lower body movement.
To find out if it contributes to higher levels of occupant safety, the researchers at IIHS examined some crash test data along with some recorded facts from real-world crash reports. For the crash test data, researchers examined up to 400 frontal crash test reports from their vehicle safety rating programme to find out if the risk of injury was less in the presence of a knee airbag. For the real-world crash reports, the researchers compiled data from the crash reports of 14 states and compared the injury risk levels in both scenarios - with and without the knee airbag.
As it turns out, in the case of indoor crash tests, the knee airbags had a negligible effect on the injury risk recorded by the test dummies. While they proved to be non-effective in moderate overlap tests, surprisingly, they were associated with increased injury risk (leg and femur) in the case of small overlap tests. As for their real-world results, they only reduced the injury risk by half a percentage point, which, in scientist speak, is considered to statistically insignificant.
Thus, as per the research, other means to reduce leg injuries in car accidents may prove to be more effective than a knee airbag.