BLACKSBURG, Va. (WRIC) — A lab at Virginia Tech has released a report that show some pricey helmets designed to protect whitewater rafters are not as effective as some that are more economical.

They made those discoveries through a battery of tests that simulate the chaotic experience of whitewater rafters who may get banged up on a particularly rough ride. The lab’s findings scientifically judged over two dozen head protections. Studies showed, of the top six models, three were retail for under $150.

The Helmet Lab rated 24 protective head coverings specifically for whitewater rafters, using data from real-world head impacts. To do that, Stefan Duma, the Harry Wyatt professor of engineering at Virginia Tech who founded the Helmet Lab and his team, designed tests to mimic realistic conditions people might experience while whitewater rafting.

In one test, a pendulum impactor struck a headform protected by one of the helmets. Inside the headform, accelerometers let the researchers measure the force of the blow. according to a summary of the research from Virginia Tech. Each helmet model was tested at three impact locations and two impact speeds to mimic the topsy-turvy situations that whitewater rafters might find themselves in.

Of all the whitewater helmet models the researchers tested, four earned five stars, the lab’s top score, and two helmets earned four. Duma and his team recommend choosing a four or five-star helmet. 

Click here to read the whitewater helmet ratings.

The whitewater helmet ratings are the lab’s eighth major release. His group has also evaluated helmets for varsity football, youth football, flag football, hockey, bicycling, soccer and snow sports.

“One of the things that’s unique about our system is we characterize each sport,” Duma said in a statement. “The way that head impacts tend to occur varies from sport to sport, and understanding those interactions is the first step to figuring out how to protect players.” 

The ratings for whitewater helmets and the other sports are all available by visiting this website.