PORTLAND, Oregon --- A new study from Oregon Health & Science University concluded that deployed air bags pose a serious risk of injury to short and tall people. "This is the first time that there is proof to substantiate the concern about small-stature occupants, and it is the first time that there has been any implication that tall people are also at risk, lead researcher Dr. Craig Newgard, an assistant professor at the university, told HealthDay News. Newgard specializes in emergency medicine and public health. Newgard said researchers studied more than 11 years of data, including results for older air bags and the newer so-called smart airbags that are designed to compensate for a person's weight. Newgard and co-author John McConnell gathered data on 67,284 drivers and front-seat passengers involved in car crashes. They concluded that air bags are effective for people of medium height --- from 5 feet 3 inches to 5 feet 11 inches tall. But they found that airbags pose a threat to people shorter than 4 feet 11 inches tall and people taller than 6 feet 3 inches. Body weight wasn't a factor in injury rates. Some experts, however, have questioned the study because it doesn't separate out data for new "smart" air bags. "There should be enough data to look at revised air bag design to see if that has made a difference," Toben Nelson, an assistant professor of epidemiology at the University of Minnesota School of Public Health, told HealthDay News. Nelson added that the finding on tall people may be "an artifact of not having many people of taller stature to see significant findings." He said there needs to be more evidence to support the conclusion that air bags pose a threat to tall people.