The NFL’s glacial movement to address growing concerns about the effects of concussions and other head injuries apparently is having little resonance in the Bay Area.

The 49ers open camp in earnest today, with head coach Mike Singletary vowing to bring back the infamous “nutcracker” drill that last year took out three of his players, including All-Pro linebacker Patrick Willis. The drill, as the Chron’s David White notes, is not exactly nuanced: It requires an offensive and defensive player to ram one another until one pushes the other outside a red line.

"I should've changed the name to the waltz or something," said Singletary, aware of criticism of the drill.

Meanwhile, the Raiders put on pads today for the first time up in Napa. Receiver Louis Murphy is out with a concussion and says he’s having trouble dealing with bright light.

"The headaches have lessened, and I'm just trying to stay out of the sunlight and just get them to calm down,” he tells the Chron. “I feel a little nauseated at times, but I'll be all right."

But Murphy says not to worry, he’ll be back in a couple days.