Most hockey helmets on the market weren't adequate to reduce the risk of head injuries when an experimental new measurement was used.

When researchers at Virginia Tech’s biomedical engineering and mechanics department bought and tested 32 helmets under various impacts, one helmet earned three out of five stars, a "good" rating.

There is no concussion-proof helmet, the researchers stressed. The aim is to have helmet manufacturers lower head acceleration and reduce the risk and number of concussions a player suffers over a season, said study author Stefan Duma, head of Virginia Tech's department of biomedical engineering.

A total of 25 out of 33 helmets tested failed to achieve an "adequate" rating of two stars out of a possible five.

The university's findings included:

1 helmet earned three stars, or “good” — the Warrior Krown 360 ($79.98 US).

6 helmets earned two stars or “adequate” ($34.99 to $159.99 US).

16 helmets earned one star ($26.98 to $269.99 US).

9 helmets earned no star ($39.99 to $119.99 US).

The Hockey STAR (summation of tests for the analysis of risks) formula was designed to evaluate helmets based on the rotational acceleration that occurs when the head turns on impact, as well as linear acceleration, or motion in the direction of the impact. Concussion is more related to rotational acceleration, neurosurgeons say.

Currently, helmets and helmet safety standards are designed to protect against injuries such as skull fractures. But better designs are possible, said Duma.

"They are what we took from the football world, where they are a little bigger, they have a larger offset, they have a different style of padding," Duma said. "We're going to be interested to see the consumer acceptance of that, but it is very much possible."

Cost had no correlation with a helmet’s safety rating.

The best way to consider the differences in helmets is by acceleration, Duma said.

The STAR formula considers level of impact, which is not the way helmets are currently certified, Alan Ashare, president of the Hockey Equipment Certification Council, told CBC News. Ashare said the council is interested in the research.

Discussing the report in an interview with CBC News, sports medicine physician Dr. Paul Echlin, of Burlington, Ont., stressed the value of educating young players and enforcing non-contact play to reduce impacts.

Changing player behaviour, such as enforcing elbowing penalties, reduces the number of times a player is hit and the likelihood of sustaining a concussion, said Mike Oliver, executive director of the National Operating Committee on Standards for Athletic Equipment.

The independent U.S. group does research and recommends improvement in sports equipment.

Blaine Hoshizaki, chair of the International Standard Committee for ice hockey equipment in Ottawa, took issue with how the measurements were made in the study, suggesting the lab tests don't replicate the variety of impacts encountered in an actual game.

CSA-approved helmets were developed to prevent major fractures and lethal bleeds, Echlin said. But the relationship between helmet design and concussions is unknown.

Hockey Canada spokesman Francis Dupont said it will continue to monitor new research and rely on the expertise of those involved with helmet quality control and the companies responsible for manufacturing helmets.