To answer this question, researchers looked at records from almost 400 emergency rooms across the US. In 1998, there were 352 hand and forearm injuries treated in these emergency rooms. Forty-four percent involved the ulna or radius, the bones on the little-finger and thumb sides of the forearm, respectively. Finger injuries came next at 23 percent. Then came injuries to the bones in the top of the hand (18 percent), and the wrist (14 percent). Multiple hand fractures were rare.

Different age groups were more prone to injure certain parts of the hand and forearm. Children ages 5 to 14 were the most likely to hurt their radius or ulna. People over 85 had the highest rate of wrist and finger fractures, possibly because of accidental falls.