AS America's most collision-oriented sport, football has long been concerned with head protection, pioneering the use of helmets, face guards, and, to a lesser degree, mouth guards.
Ironically, well-padded heads have sometimes become hazards, a fact that the two surviving helmetmakers know all too well. Reckless players turn themselves into human spears, endangering both themselves and those being tackled or blocked. Since the 1970s, football officials have tried to prevent players from using their heads inappropriately.
This year, for example, the National Football League has expanded the reach of the rule that prohibits using the head to initiate contact, especially against ''defenseless'' players. Now tacklers are barred from battering opponents with their foreheads or face guards, not just with the tops of their helmets.
Greg Aiello, the league's director of communications, says the application of the rule was fine-tuned after numerous concussions were reported last season. Thus far in 1995, 11 players have been fined for illegal tackles, seven for $12,000 each, and the others for lesser amounts.
''We're a little liberal on the tackling [rules] when it's a 250-pound fullback with a head of steam charging at a linebacker,'' says Jan Van Duser, an NFL executive. Under those conditions, ''it can be hard to get your head in an appropriate position. But when a player eyeballs a standing quarterback, when there's no excuse for that way of tackling, then we apply the rule.''
Football turned the corner in considering the head and neck in the 1970s, when a number of lawsuits rocked helmetmakers.
''That was a serious time, with 25 or 30 players being paralyzed each year,'' says Frederick Mueller, director of the National Center for Catastrophic Sports Injuries at the University of North Carolina, Chapel Hill. In 1968, 36 players died from injuries in amateur and pro football games and practices.
Since then, he says, there has been a marked decline in fatalities and catastrophic injuries. In 1990 there were no reported deaths from playing football for the first time since 1931, the first year such records were kept.
Much of the credit for the turnaround, most observers agree, falls to the rulemakers, who have tried to outlaw unsafe blocking and tackling, and to coaches who have taught proper techniques.
The football community also benefits from improved equipment made by two reputable helmet manufacturers with long track records - Riddell, Inc., of Chicago and the Schutt Sports Group of Litchfield, Ill. They are the only survivors in an industry that has seen many competitors fold or stop making helmets since 1970.
Asked how close football is to having no helmet suppliers, Julie Nimmons, Schutt's president, says, ''Pretty close - one product-liability lawsuit away.... That's all it would take for the two remaining manufacturers to be gone.''
Mrs. Nimmons is chairwoman of the Sporting Goods Manufacturers Association and a strong advocate of product-liability reform. Congress continues to look at the subject and has a bill under consideration, but Nimmons says its passage wouldn't necessarily reduce lawsuits.
Football helmets must achieve established minimum performance standards to receive the approval of the National Operating Committee on Standards for Athletic Equipment. Every helmet comes with a ''lengthy instruction manual on proper fitting,'' says a Schutt spokesman. Since 1976, all helmets have carried a warning label stating that those wearing it are not impervious to serious injury and concludes: You use this helmet at your own risk.
But the protective cocoon of the helmet may send the wrong signal to some players with a reckless disregard for their own and others' safety.
THIS raises an interesting question: ''Can you devise something that looks less protective or makes a player feel he is not so indestructible?'' Ken Nimmons, a Schutt executive, asks. ''That's the question that everybody would like to answer.''
Breakaway face masks, which proved unreliable, were tried. Air-bag technology could be on the horizon. A foam-rubber cap that fits over the top of the helmet is seen occasionally. In the foreseeable future, predicts Frank Pupello, equipment manager for the NFL's Tampa Bay Buccaneers, helmets will fit into a housing on the shoulder pads.
Makers of equipment realize they don't control change. ''We have to respond to the needs of the game,'' Julie Nimmons says. ''We cannot be making the rules.''
Neither she nor the NFL's Van Duser foresee any radical change in equipment soon.
''There's a certain conservativeness about the player,'' says Van Duser. ''He knows what's tried and true, and what works for him.'' If anything, the trend among backs and receivers is to strip off pads to enhance speed.
Given this, maybe one-piece body suits, envisioned by some, might have a future after all.