The entertainment industry has improved its portrayals of walking, cycling and boating in movies aimed at children, but half of scenes still show risky behaviour, U.S. researchers found.

Unintentional injuries are the leading cause of death among children in Canada and the U.S, and children often act out when they see on the silver screen.

Previous studies found movies marketed to children rarely portrayed safety measures such as wearing seat belts, so the researchers set out to test if depictions have improved. Jon Eric Tongren of the U.S. Centers for Disease Control and Prevention and his colleagues reviewed the top-grossing movies rated for general audiences or parental guidance per year from 2003 to 2007.

In Monday's online issue of the journal Pediatrics, the study's authors reported:

22 of 958 scenes depicting children or adults involved crashes or falls, resulting in three injuries and no deaths.
75 per cent of boaters wore personal flotation devices.
56 per cent of motor vehicle passengers were belted.
35 per cent of pedestrians used crosswalks.
25 per cent of bicyclists wore helmets.
During the same time period, seat belt use in the U.S. population was 82 per cent, and bicycle helmet use by children was estimated at 41 per cent in 2003.

"The entertainment industry has improved the depiction of selected safety practices in G- and PG-rated movies. However, approximately one half of scenes still depict unsafe practices, and the consequences of these behaviours are rarely shown," the study said. Unsafe practices included not wearing elbow and knee pads when skateboarding.