The parents of two teenage girls from eastern Pennsylvania who have suffered concussions playing soccer say the sport’s governing body hasn’t done enough to protect young female players.

In a suit filed Friday in U.S. District Court in Pittsburgh, the families and their lawyers say the U.S. Soccer Federation and its largest member, the U.S. Youth Soccer Association, have failed to mandate the use of protective headgear despite evidence that it works.

Lawyers for the families say recent studies show modern headgear could reduce concussions.

The suit was brought by attorneys for two girls — Alivia Sherman and Adiah Siler — in the Scranton and Allentown areas; they are seeking class-action status that would cover all current and former female youth soccer players, and more plaintiffs are expected to be added in a future complaint.

One of the lawyers, Joseph Murphy of Pittsburgh, said U.S. Soccer has not kept up with medical research on newer headgear.

He said the federation still maintains its stance from 2005 in which it said the gear doesn’t protect players and may even cause harm by providing a false sense of security for them when they head the ball.

But Mr. Murphy said developments in technology since then clearly show that modern Kevlar headgear is effective.

Although other class actions have been filed over concussions, Mr. Murphy and attorney Matthew Logue, also of Pittsburgh, said this is the first one specific to female youth players. They said young girls are at particular risk in part because their necks are not as strong as boys’ or older players.

“We’re at a point where girls’ soccer is producing more concussion events than boys’ football,” said Mr. Murphy.

Mr. Logue said U.S. Soccer already requires players to wear shin guards and other equipment. He said it’s time the governing body requires headgear, too.

U.S. Soccer did not immediately respond to a request for comment.

There are 1.7 million girls registered nationally with U.S. Soccer. The federation previously outlawed heading the ball for all players 11 and under.

Correction, posted May 29, 2018: In an earlier version of this story, the part of Pennsylvania the girls were from was mischaracterized.

Torsten Ove: tove@post-gazette.com.

First Published: May 29, 2018, 9:12 p.m.