Barcelona ’92 OLYMPICS / DAY 13 : Survival Is Reward Enough to Johnson : Decathlon: He takes bronze after struggling throughout day because of injury. Zmelik wins.

Because the children of America need a hero, Dave Johnson kept going. So that teen-agers will know it isn’t OK to quit, Johnson didn’t. So he might praise God, Johnson ignored a stress fracture in a foot he described as “a bloody stump” and limped to an Olympic bronze medal in the decathlon Thursday night.

Those were the reasons Johnson gave for his determined and ultimately doomed effort to claim the gold medal that he was favored to win.

Some had projected that America’s hope for its first decathlon gold medal since 1976 rested with Dan O’Brien, the world champion. O’Brien was here Thursday, but working as a television commentator. He failed to register a height in the pole vault at the U.S. Olympic trials in June.

After that, Johnson became the favorite, having compiled the highest score in the world this year. But when he discovered a stress fracture in his right foot, merely finishing the two-day, 10-event competition became Johnson’s mission.

He accomplished that in the heavy humidity in Montjuic Stadium. Johnson could not catch two younger, injury-free athletes--Robert Zmelik of Czechoslovakia, who won the gold with 8,611 points, and Antonio Penalver of Spain, who won the silver with 8,412. Johnson was third with 8,309.

Johnson, with his taped and swollen foot aching, stood after the last event, the 1,500-meter run, and surveyed the scene. Seven decathletes lay sprawled on the track, exhausted. Penalver was celebrating with his countrymen and Zmelik was smiling, having won the prize.

It reminded him, Johnson said, that he didn’t compete in the decathlon for gold medals.

“If I would have quit, if I decided not to go for it, there would have been a lot of little kids who would have thought it was OK to quit,” Johnson said. “I wouldn’t want to let them down. I give this all to God.”

Johnson’s injured right foot let him down. It is an injury he has known about for weeks but kept secret, lest it provide a psychological edge to his opponents.

The secret was out after his first day of competition here, though, and Johnson began the second day, Thursday, anxious about the 110-meter hurdles. The pounding in that race might have been enough to cause his foot to give way.

His time of 14.76 seconds was disappointing, but Johnson was encouraged that his foot held up.

“It was a miracle that I got through the hurdles,” he said.

And after passing that test, Johnson knew he would go on.

“My foot’s going to have to fall off to make me stop,” he said.

Even with his strong second day--he holds the world record for second-day decathlon points scored--Johnson was still in a precarious position. He had begun the day in ninth place but lost the potential for many points in the pole vault when his foot caved in under the stress.

“My arch is wasted,” he said.

Johnson had cleared 16 feet 8 3/4, but so had Zmelik. Johnson’s coach, Terry Franson, had calculated that to stay even, Johnson would have to clear three heights higher than the Czech.

But Zmelik was having an incredible day.

“I keep waiting for him to fall apart,” Franson said of the Czech. “But he never does.”

The vault continued for more than 3 1/2 hours. Zmelik failed to clear 17-0 3/4, but Johnson still had one more attempt. With his foot “exploding,” Johnson passed his final vault.

“It hurt so much I could hardly walk on it,” he said.

There were two events remaining, but the medals were determined in the pole vault. Johnson said the injury cost him as many as 500 points--enough to win the gold.

Every time he tried to make up ground, Johnson failed.

He had hoped for a big throw in the javelin, perhaps his best event. But on his third attempt, he tried to signal the officials that he was going to wait until a race was finished before throwing. They misunderstood and would not allow him to throw after the two minutes allotted for his attempt had run out.

Johnson, though, was not downcast, having taken solace in overcoming prohibitive odds in completing the event.

“I’ve climbed a mountain,” he said. “I got as high as I could.”

Track and Field Medalists

* MEN’S DECATHLON

GOLD: Robert Zmelik (Czechoslovakia)

SILVER: Antonio Penalver (Spain)

BRONZE: Dave Johnson (United States)