Football equipment managers nationwide will receive yet another reason to reassess their helmet inventory on Tuesday, when a Virginia Tech research report reveals that two models popular among teenagers might be allowing high rates of concussions.

The Riddell VSR-4, a recently discontinued model still worn by about 75,000 high school and college players, and the Adams A2000, a less prevalent helmet now available for purchase, were the lowest-ranked models in a new testing regimen designed to estimate concussion risk. The full results were to appear on a Virginia Tech Web site as the first publicly available objective data on football helmet performance.

Riddell’s Revolution Speed model earned a five-star rating on the Virginia Tech scale, followed by five four-star helmets made by Riddell, Schutt and Xenith. Only helmets designed for players of high school age and older were examined.