ANN REINKING swayed, spaghetti-like in the center of a tightly bunched, squiggling mass of dancers--the Queen Worm surrounded by devout followers.

Stripped down to a sleek black unitard and black leg-warmers with a black sweater knotted around her hips, Reinking stood out like the perfect, prized licorice drop in the middle of her dance students' jellybean jumble of leotards.

Reinking--the high-kicking, hip-twitching star of "All That Jazz" and "Annie"--brought a little bit of Broadway to Bethesda yesterday when she taught two master classes at the Feet First studio to delighted area dance teachers, performers and students.

"I enjoy teaching classes like this one to fill in the gaps. I learn from teaching. Having to break things down and explain them makes me a better dancer," said Reinking, who is in between filming a TV special and preparing for a one-woman show at Carnegie Hall in October.

"Also, it's interesting to see the cul-de-sacs of culture around the country."

And from their eager response, the 70 dancers who paid $10 each for the privilege of picking up pointers from Reinking were obviously thrilled she came to town.

When Reinking urged the morning class of professional-level dancers to "just be a can of worms," the room became Snake City. The dancers flailed arms, gyrated bodies and wriggled hips in their very best worm-like manner.

The one feature that saved the black-clad Reinking from sophisticated severity was her frequent, vibrant smile. Throughout the "wormy combination," which she adapted from the Broadway show "Pippin," Reinking called out encouragement--"That's it," "Good, good"--to the students trying to mimic her seemingly jointless movements.

After everyone appeared wriggled-out, Reinking clapped her hands and rasped, "That's enough torture," in her trademark rusty-edged voice. She moved to the front of the room, paused momentarily and turned to face the breathless, perspiring dancers--many of whom were playing hooky from their "real life" jobs.

"There's one problem I'd like to talk about," Reinking said quietly. "Some of you weren't paying attention or following. I said don't forget your demi-plie' about five times, and a lot of you still didn't demi-plie'. If this were an audition situation that would count you out.

"Typically, a choreographer has six precious weeks for 17 numbers. So he is going to pick people who are going to pay attention and pick up the combination fast. It's a sorry tale to tell, but there are lots of brilliant dancers who don't get jobs because they don't use their heads.

"You have no control over how tall you are or how long your legs are, but you do have control over how much you concentrate. It's to your advantage to work your brain as well as your body. The rest is up to fate."

Fate has been exceedingly kind to her, the 33-year-old dancer acknowledged over a carry-out Chinese lunch in a back room of the studio before the afternoon class of intermediate dancers.

"I was up for parts in 'Charlie's Angels' and 'Three's Company,' but other people got them," she said, stabbing a plastic fork into a carton of steamed dumplings. "At the time I was very disappointed because I knew the shows would be tremendous hits.

"But if I had done either I would not have done the following: 'Chorus Line,' 'Dancin',' 'Chicago,' 'Movie Movie,' 'All That Jazz' and 'Annie.' Am I happy with the way things turned out? For heaven's sake, yes."

The woman who seems so tall and striking in celluloid is surprisingly short andbroad-shouldered in person. "People always remark on how I'm not as tall as I look in film," said Reinking, who is 5 feet 7. "I tell them about the time I saw Lassie on a studio lot, and she was this tiny scruffy dog. Film makes you larger than life."

Reinking's eyes are the same stormy blue-gray as on firm, but are less startling without the fringe of thick mascara. Her body is tight-muscled, with a powerful torso that looks more like a swimmer's than a dancer's. Until she starts moving her arms energetically to illustrate a point or caps a sentence with a chin-to-shoulder "Fosse-esque" pose.

Today her relationship with choreographer-director Bob Fosse, she said, "is very good." She was Fosse's girlfriend when he suffered a heart attack while rehearsing the Broadway musical "Chicago," starring his ex-wife Gwen Verdon--the imitation-of-life situation in 'All That Jazz,' in which Reinking portrayed the girlfriend of director-choreographer Joe "It's Show Time!" Gideon.

As Fosse's former prote'ge'--"If it weren't for him, I might still be doing one two three, kick"--she appears to retain a friendly affection for him. "We parted very amicably, and we occasionally talk on the phone. I don't see him very much, but when I do see him it's very good. We still have the communication of two people who know one another very well."

Now, however, her affections are directed toward "a very nice civilian person in the business world"--a four-year relationship affirmed by a large blue sapphire on her left hand. "By civilian, I mean he's not one us show people," she said with a husky giggle. Such mixed-career relationships work best, she said, "because the real problem with a career--if you're serious about it--is that you can get so wrapped up in that world you lose your perspective."

Reinking fell into "that trap" about five years ago. "Basically, the musical theater is a blob of about 60 people who do all the shows," she said. "If you make them your entire universe, you can get in trouble. I was at a point where I was overdoing it, trying to please everyone and never miss an opportunity.

"I remember one morning sitting on my bed exhausted, crying, down to about 102 pounds with a severe case of bronchitis. I decided 'This is stupid,' and I changed my attitude. I went back to the things my parents a Seattle hydraulic engineer and a homemaker taught me. The basics of being practical and looking out for myself. I realized it wasn't the end of the world if I didn't get a show. I wasn't going to lose my self-respect or my family or my two best friends."

This realistic attitude--"I think of myself, basically, as a very practical person in black bugle beads"--meant, she said, "using more discretion in what I picked to do."

Now, she is looking toward more acting. "A dancer can only dance so long," said Reinking, who admits, "I never used to have to warm up, but now I have to or I get stiff. But an actress can act forever."

She has just returned from London where she filmed a BBC special, and she recently completed an ABC-TV special, "Parade of Stars," to be televised May 22. "All the stars of today recreate the stars of yesteryear at the Palace. I'm doing the Dollie Sisters with Pam Dawber. 'Oh You Beautiful Doll' and 'Pretty Baby' were their songs. Debbie Allen does Josephine Baker, James Whitmore is Will Rogers. It was great fun."

She has also purchased the rights to TV reporter Betty Rollins' book, "Am I Really Getting Paid For This?," which she is having developed into a movie script in which she hopes to star. What she'd really like to do is "a comedy with a lot of pathos."

The one thing she is ruling out, "at least for now," she said, is a TV series. "I would love to do one, but the only problem is they really mainly film in California, and I'm a New York girl.

"I really don't want to leave my home and my friends for that long, at least at this point in my life. It's hard to keep a family and a life and a relationship and all that stuff together by commuting on the weekends."

Besides, she said, there's plenty to do on the East Coast without that sacrifice.

"Heck, just let me perform. I'll dress up like a chicken with a derby as long as I get to get out there and have fun."