Six pages deep and below the fold, the news this week that the Kansas City Chiefs had acquired running back Michael Bennett from the New Orleans Saints likely didn't draw a lot of notice, but it should have, if only for what the Chiefs said the trade did not mean.

It did not mean, they said, that Priest Holmes would retire.

Right. And it did not mean that he would not retire, either.

Holmes' helmet hit the helmet of Chargers' linebacker Shawne Merriman on a sunny San Diego Sunday last October, with the Chiefs' record-setting slasher sustaining neck and spinal cord injuries that were close to catastrophic. Nearly 10 months later, doctors continue to hold him out of contact drills, obviously because another sickening helmet-to-helmet collision might be devastating.

"Given all the contact you see, it's amazing that there are only a very few of those types of injuries," said Dr. Mark Lovell, the UPMC neuropsychologist was saying the other day. "It's a testament to what great athletes they are and, specifically, to how strong their necks are. These kinds of collisions are going to happen; it's the nature of the game, but the NFL has been very vigilant, I think, to the point where it's now illegal to initiate contact with the head.

"Still, when you see [a helmet-to-helmet hit] and hear the 'crack,' it's hard to watch."

The fact that Lovell has been working with the NFL toward a better understanding of the potential head trauma that is endemic to this game represents something of a breakthrough, the more dramatic part of which has come about only in the past five years. Not only has Lovell developed and spurred the proliferation of ImPact (Immediate Post-concussion Assessment and Cognitive Testing) but, as he points out, the league finally has begun to enforce its own rules against unsafe techniques.

That's why a player like John Lynch now gets fined $75,000 for a helmet-to-helmet hit. That's a pretty substantial statement, $75,000. Moreover, the league's officials, who probably still don't call it enough, are not afraid to change the course of a game as the result of an unsafe act. In December, Lynch drilled Kansas City's Eddie Kennison helmet-to-helmet after an incomplete pass deep in Denver territory. The penalty gave the Chiefs a first down at the Broncos' 4, from where they scored on the next play to take a 31-27 lead. Lynch has been fined by the league at least four times for this stuff.

Research at UPMC and by the National Center for Catastrophic Sport Injury Research indicates that younger football players, especially at the high school level, are more at risk of devastating consequences from helmet-to-helmet collisions than the pros, and that they are slower to recover from the effects of concussion.

"We don't know why, but it could be that the proportion of the weight of the heads to the rest of their bodies is larger," Lovell said. "It could be that their necks aren't as strong, but the other part is that their brains are still developing."

It's one thing for an elite athlete of demonstrated strength to endure a helmet-to-helmet incident, but quite another when you're 5 feet 8 and 160 pounds, as was one of the high school players who last year followed a helmet-to-helmet hit with what is sometimes called clinically an "incomplete neurological recovery." He's a quadriplegic.

It's a solemn responsibility for coaches to insist on proper technique on this issue. Players cannot be turning themselves into missiles on the field. They must block and tackle with their heads up, and running backs must resist the urge to lower their heads to absorb contact.

But for the first time since I began writing occasional pieces about this too many years ago, statistical trends are markedly better. According to the NCCSI's Annual Survey of Catastrophic Football Injuries (1977-2005), over the past 29 years, 256 football players have had incomplete neurological recoveries from spinal cord injuries, 211 of whom were high school players, 31 collegiates, five youth players and nine pros. But, in 2005, such injuries totaled only three, a dramatic reduction from the year before, and the incidence of catastrophic injuries is very low on a 100,000-player exposure basis. For 2005, the rate of such injuries was 0.16 per 100,000 participants.

"Things have gotten a lot better over the last five years," Lovell said. "The NFL has done a lot of research on the way helmets are designed and built, even to the extent that they've toughened the standards for the way helmets are tested."

As another season of regularly scheduled mayhem begins, it doesn't matter if you're a newly acquired replacement for Priest Holmes or a 160-pound wideout who's playing essentially because chicks dig it, the best instruction is the same: Heads up.