From a distance it must look like a playground gone wild. There are ribbons, (jump) ropes, clubs, (hula) hoops and sometime balls. There is running, dancing, jumping, catching, somersaults, throwing . . .

Welcome to the esoteric world of rhythmic sportive gymnastics (or RSG, please).RSG made its competitive debut in Utah Friday night with none other than the U.S. Olympic Trials. A smallish crowd of 3,857 turned out in the Salt Palace for the event, but no one was complaining. "That's a good crowd," said one RSG official. "That's about what we usually draw."

When you're a relatively new sport, you take what you can get.

You also do a lot of explaining. When the first night's competition was finished, one dazed reporter asked her colleagues, "Does anyone know what happened out there?" The post-competition press conference turned into a cram course on the sport, with answers provided by the top three competitors.

Indeed, no one knew quite what to make of RSG. Early in the competition, the fans sat on their hands, apparently unsure if clapping was allowed. Then the announcer told them, "Feel free to applaud." That loosened up the mood in the Palace.

"I think if people see the sport, they'll come see it again," said Michelle Berube, one of the sport's top performers in this country.

Warning: this sport has little in common with the other gymnastics - called artistic gymnastics, although the names would seem to be reversed. Where Mary Lou explodes, Diane Simpson swirls and twirls (someone said there is a difference), wrapped in a matching crepe-paper ribbon.

"We get our share of abuse, that's for sure," said Susan Polakoff, the RSG's public relations dirrector. "People compare it to synchronized swimming. It's easy to ridicule, but the stuff they do is incredible."

Even the most cynical observer is forced to agree. "They're acrobats, gymnasts, dancers and jugglers," Polakoff continues.

And here comes a summary explanation of RSG, with assistance from the media guide: Gymnasts perform leaps, rolls, spins, etc., while throwing, catching or even rolling the apparatus (the aforementioned playground equipment). Many of the moves are performed while the apparatus is hanging somewhere in the air, yet caught, just in the nick of time, with one deft stretch of a hand (or even a foot). Judges watch for the details: How high was the toss (the higher the better, and some are as high as 35 feet)? Does she catch it (drops are, of course, a no-no)? How long does the gymnast have to hesitate to make the catch or does she arrive just in time to make the grab?

Their are some variations of the sport. Every four years, the fifth apparatus is slipped back into competition and another apparatus is pulled out. This year, for instance, the ball is excluded from individual competition, but is included in group RSG. Oh, yes, there is group RSG, but not in the Olympics. Group RSG consists of six gymnasts who somehow play a finely choreographed game of catch with six balls or three hoops and three balls. Confused? "It's really wild," says Polakoff.

Ironically, RSG was the original form of gymnastics. It is said to have existed in some form (the apparatus was probably scarves) in the ancient Olympics. But it has long since been surpassed in popularity by artistic gymnastics and the Retton-Korbut-Comaneci, at least in this country. "It is very popular in Europe," said Polakoff. "In Eastern Europe their (RSG athletes) are treated like our movie stars. They're idols and they sell out the arenas."

That notwithstanding, RSG has gone to great lengths to separate itself from its sister sport. Handsprings, aerials and "other flashy moves" are not allowed. Exercises are performed on the same 40x40 carpet, but without the springs.

"Rhythmic gymnastics is more graceful, more dance oriented," says Polakoff. "It attracts the more elegant, dancer-type athletes." They are also several years older and less explosive.

RSG didn't become an Olympic sport until 1984. The top American finished out of the money (11th, even with the boycott), as expected. American RSG is still well behind its Eastern Bloc counterparts, who have been practicing the sport in some form since the turn of the century. It wasn't until the past two decades that the sport took hold in the U.S. Most of the American athletes originally came to RSG from artistic gymnastics because, according to one official, "They were older, or injured or not strong enough for artistic gymnastics." But as the sport has developed in the U.S. the athletes are now starting their gymnastic careers in RSG.

"The level of ability is growing," said Simpson.

Watching Friday's eight competitors dance through their four routines, Polakoff seemed to agree. "I've never seen them look this good."