Front- and side-impact airbags, designed to protect the head and spine of vehicle occupants, now prove to have unexpected benefits. A study published in the Journal of the American College of Surgeons shows that front-impact airbags reduced risk of kidney injury by 45.3 percent, while side-impact airbags reduced risk by 52.8 percent. Analysis of 2,864 records (1996-2008) from the U.S. Crash Injury Research and Engineering database gave the surprising findings. Vehicle crashes are the most common cause of blunt force trauma to the kidneys, accounting for about half to two-thirds of such injuries.