Looking Up, Joyner Is Down : Track and field: The prospect of pole vaulting terrifies him and inhibits his plans of trying to compete in the decathlon.

Jackie Joyner-Kersee couldn’t help herself. Standing on the backstretch of the track at Saturday night’s Sunkist Invitational with her brother Al, Joyner-Kersee fired a verbal elbow to the ribs.

Pointing to the pole vault area, where the crossbar was well above the Sports Arena floor, the older sister remarked to her younger brother, “That’s 17-(feet-)8. You’ve got to vault that!”

The frightening reality of flight on a pole might have caused Joyner to pause in his newly launched career as a decathlete. Joyner got into the family business--multi-events--with a foray into the Sunkist’s three-event competition, featuring Olympic decathlon champion Robert Zmelek and world record-holder Dan O’Brien. Thankfully for Joyner, pole vault was not on his program.

Joyner’s career change was dramatic. He was the 1984 Olympic gold medalist in the triple jump and has hurdled. However, in addition to inexperience in the decathlon’s three throwing events, Joyner professes a mighty fear of the the pole vault.

He noted that he is having trouble clearing 11 feet, well below what even modestly talented multi-event performers are expected to clear. “I’ve only got seven feet to go,” he said.

Joyner competed under his sister’s eye. His first event was the 50-meter hurdles. Not long after his third-place finish in that event, he repaired to the backstretch to prepare for the 50-meter dash and long jump, the other events on his program. Joyner-Kersee couldn’t resist some impromptu coaching.

“ ‘Oh yes,’ I said, ‘number one, we’ve got to start training. . . ,’ ” she said, laughing. “Number two, you could tell . . . I don’t know what kind of speed work he’s doing. . . .” The lesson trailed off into laughter.

Joyner-Kersee might be laughing because she knows the rigorous training and devotion that multi-event competition demands. She won the gold medal in the heptathlon in last summer’s Barcelona Olympics, competition in which she holds the world record.

Her gentle kidding may be equal parts sibling rivalry and sibling knowledge, for, as Joyner-Kersee says, “My brother is too lazy for the decathlon.”

“I don’t doubt his ability,” she said. “It’s just that it’s going to be tough. You’ve got the 1,500 . . . pole vault. It would help him if the people around him had experience in the event. It’s really tough. I’ve told him. He’ll have to learn the hard way.”

Joyner said he became inspired after watching the decathlon at the U.S. Olympic trials last summer. He went back to his hotel, went to bed and couldn’t sleep. Joyner got up and went running through the streets of New Orleans at 3 in the morning.

His sister used to be his inspiration. Now Joyner must find his motivation from mastering 10 difficult events. Joyner-Kersee said Saturday night that it took from four to eight years for a heptathlete to master the events.

What of her brother, who is beginning to embark on a path he hopes will lead him to the 1996 Olympics in Atlanta?

“It’s going to be tough,” Joyner-Kersee said. “He’s got a lot to learn in a little time. If nothing else, training for the decathlon may help his triple jumping.”

Never mind the pole vault.