The study by the Centers for Disease Control and Prevention is the first comprehensive national look at the role brain injuries play in fatal elderly falls. It examined 16,000 deaths in 2005 that listed unintentional falls as an underlying cause of death.

CDC researchers found that slightly more than half of the deaths were attributed to brain injuries. The other deaths were due to a variety of causes including heart failure, strokes, infections and existing chronic conditions worsened by a broken hip or other injuries sustained in a fall.

"A lot of people don't think a fall is serious unless they broke a bone, they don't think it's serious unless they break a hip. They don't worry about their head," said Pat Flemming, a senior physical therapist and researcher at Vanderbilt University