Expressions of grief after the death of Teddy Balkind, a high school hockey player in Connecticut, have spanned the ice hockey world, from pregame moments of silence in New England to tributes on “Hockey Night in Canada” broadcasts to hockey sticks set tenderly on porches from Manitoba to Minnesota to Maine.

Balkind, 16 and a sophomore at St. Luke’s School, in New Canaan, died after a player’s skate blade cut his neck in an on-ice collision during a game last Thursday in Greenwich, Conn. Such fatal accidents are rare, but when they happen they horrify and evoke a powerful “but for the grace of God” feeling, chiefly among hockey parents. Few know the feeling the way Dr. Michael Stuart, the chief medical and safety officer for U.S.A. Hockey, does.

Stuart helped write the organization’s policy on neck protection. He also watched his son sustain a similar injury as a defenseman at Colorado College 24 years ago. Mike Stuart survived after 22 stitches closed what his father described as an “almost ear-to-ear” gash.

“It could have been the same result for our own son,” the doctor said of Balkind’s injury. “I wish this young man had the injury our son had. This brings back very vivid memories, and this is very near and dear to my heart.”

The death of Balkind, a 10th grader, has refocused scrutiny on the use of neck protection in amateur hockey in the United States.

U.S.A. Hockey, the national governing body for the sport, recommends players wear neck guards that cover as much of the neck as possible, but it does not mandate they do so, making the United States somewhat of an outlier on the international hockey scene, despite having done considerable research on the topic.

The governing bodies of hockey in Canada and Sweden mandate neck guards for amateurs, as do many European leagues and the International Ice Hockey Federation.

In the United States, whether players must wear neck protection is left up to individual hockey associations and oversight boards. The result is a patchwork of policies.

Balkind’s school, St. Luke’s, and the team’s opponent in the game, Brunswick School, of Greenwich, play under the rules of the New England Preparatory School Athletic Council, which does not require players to wear neck guards.

By contrast, the Connecticut Interscholastic Athletic Conference, which sets rules for high school hockey in the state, but not for prep schools, mandates that all players wear “commercially manufactured throat guards designed specifically for ice hockey.”

“Every single hockey player in the United States should be wearing one because U.S.A. Hockey recommends it,” Stuart said, adding that instituting a mandate is a regular agenda item at the organization’s annual conference — and will certainly be again — when the conference begins on Thursday.

“It is very well that a mandate could come forward,” Stuart said. “Whether or not that can prevent this from ever happening, whether it will have any effect, I guess will remain to be seen.”

Neck guards may be the most disliked piece of hockey equipment among players. They are typically made of Kevlar or nylon, foam and Velcro, and players, particularly children, complain that they are hot and cumbersome.

It is not clear whether Balkind was wearing neck protection when he was injured. Michael West, the athletic director at St. Luke’s, and a school spokeswoman, Nancy Troeger, declined to comment, saying they were focused on giving their community the privacy to mourn.

Nor is it clear whether a neck guard would have prevented his injury.

Still, more than 63,000 people have signed an online petition started by a friend of Balkind’s to make neck guards a mandatory piece of equipment.

“It feels like there’s no reason not to have neck guards required in the United States, and it feels like we had to lose a young hockey player to bring awareness to the topic,” said the petitioner, Sam Brande of Wayland, Mass., who attended summer camp with Balkind for years.

Brande, 16 and a serious hockey player, said he began wearing a neck guard last week after Balkind died. “An injury like that seemed impossible to me,” Brande said.

Skate lacerations are among the most gruesome injuries in sports. But they are relatively rare, and skate lacerations to the neck are rarer still.

A U.S.A. Hockey survey in 2008 found that just 1.8 percent of players reported ever being the victim of, or the witness to, a cut to the neck from a skate during play. Thirty-three players who reported being cut on the neck sustained wounds that were not life-threatening. About one in four who were cut, 27 percent, were wearing neck protection.

Overall, 45 percent of the 26,342 respondents reported regularly wearing a neck guard, according to the survey, which U.S.A. Hockey has described as the most extensive one conducted.

However, the organization subsequently concluded that the survey did not provide enough information to support mandating neck guards.

“To date there is sparse data to describe the prevalence of such an occurrence, the severity, or whether or not a neck laceration protector (neck guard) reduces risk or severity,” reads U.S.A. Hockey’s “neck laceration protector” policy.

It also says: “U.S.A. Hockey recommends that all players wear a neck laceration protector, choosing a design that covers as much of the neck area as possible. Further research and improved standards testing will better determine the effectiveness of neck laceration protectors.”

Since then, U.S.A. Hockey has documented 13 incidents of neck lacerations caused by skates in the course of play, or about one a year, according to data provided by the organization.

The organization’s philanthropic arm, the U.S.A. Hockey Foundation, has also funded a handful of studies that have been published in the Clinical Journal of Sport Medicine on various aspects of neck guards, including their effectiveness at preventing cuts and their impact on a player’s range of motion.

Almost all the neck guards tested prevented cuts in low-force simulations, but all of them failed in high-force simulations.

“If U.S.A. Hockey is an outlier, it’s in that we’ve done more research and spent more time and effort on trying to make neck lacerations less of an issue than anybody else in the world,” Stuart said. “There’s not much other research going on about this.”

Before Balkind’s injury, the two most prominent cases involved N.H.L. players, both of whom survived.

Buffalo Sabres goalie Clint Malarchuk was slashed in 1989 when an opposing player, Steve Tuttle of the St. Louis Blues, crashed into the goal crease and his skate blade sliced Malarchuk’s carotid artery and nicked his jugular vein.

In 2008, Florida Panthers forward Richard Zednik sustained a similar injury when his teammate Olli Jokinen lost his balance during a battle for a loose puck along the boards and his skate caught Zednik’s neck.

In 1975, another New England school player, the 18-year-old defenseman James Dragone Jr., bled to death when the skate of an opposing player cut his neck during a game in Boston. Nearly 3,000 people attended his funeral.

In 2017, in a girls’ game in Guelph, Ontario, 16-year-old Cassidy Gordon escaped serious injury after another player’s skate hit her in the neck. She was wearing a neck guard.

“It may have value in protecting from a neck laceration or the severity of a neck laceration,” Stuart said. “Although that is unproven, it certainly has enough logistical sense that U.S.A. Hockey recommends it for all players, and if mandating it would even save one potentially catastrophic injury or death, then I think U.S.A. Hockey would be the first to do that.”