* Now that the NHL lockout is over and the league has resumed games, concussion protocol has again become a hot topic, according to the New York Times.

The issue has received even more attention after the Colorado Avalanche lost its captain, Gabriel Landeskog, to a concussion.

Colorado’s Gabriel Landeskog, the youngest captain in N.H.L. history and last season’s Calder Trophy winner as the league’s top rookie, did not play last week. But what happened to him in the aftermath of a heavy body check he received raised concerns that the league’s concussion protocols may be out of step with current scientific research.

On Jan. 26 in San Jose, Landeskog was on the wrong end of a crushing first-period hit from Sharks defenseman Brad Stuart, whose shoulder cracked into Landeskog’s head.

The hit was deemed legal by the referees, a call that passed review by Brendan Shanahan and the N.H.L.’s hockey operations department. Although Rule 48 on head checking was strengthened two seasons ago to penalize players who target an opponent’s head, if contact is made in the course of delivering a full body check, the hit is legal.

Landeskog returned to the ice later in the game, reportedly passing the NHL’s concussion test. But two days later he was out with post-concussion symptoms.

The incident comes not long after superstar Sidney Crosby missed nearly an entire season with multiple concussions. The league even changed its concussion protocol in light of Crosby’s injuries. But now there are calls for more changes.

The N.H.L. has made strides on concussions in many areas, but cases like Letang’s and Landeskog’s suggest that even the league’s current protocol for concussion assessment may be too lenient, allowing players to return to the ice too soon after a jarring hit to the head.

Last November in Zurich, scientists and sports administrators gathered for the Fourth International Consensus Conference on Concussion in Sport to review the latest research. According to Ken Dryden, the Hall of Fame goalie and former member of Canada’s Parliament who attended the event, “the Zurich conference agreed to a clear, certain message: ‘When in doubt, sit them out.’”

That is not yet the standard in the NHL, where teams and the players are ever eager to shake off injuries, even from blows to the head, and get back in the game.

– Bill Bradley, contributing editor