NEW YORK, NY.- Steve Paxton, who helped radically upend ideas about dance as a member of the 1960s collective Judson Dance Theater in New York City, and who developed contact improvisation, a movement form that is now practiced around the world, died Tuesday at his home in East Charleston, Vermont. He was 85.

The death was confirmed by Lisa Nelson, his longtime collaborator and lifetime partner.

“You could say it all comes from walking,” Paxton said of his contributions to dance in a 2012 Artforum interview. At the start of his career, in the early 1960s, he was a virtuosic dancer in the companies of José Limón and Merce Cunningham, but his aesthetic curiosity soon turned to less technical, more pedestrian activities.

Inspired by experimental artists like Cunningham and the members of the Living Theater, Paxton was looking for new territory. “I was trying to find concepts that hadn’t been dealt with by these people, who we thought had already done everything,” he told dance historian Sally Banes for her book “Terpsichore in Sneakers” (1980).

With Yvonne Rainer, Lucinda Childs, Trisha Brown and other members of what would soon become Judson Dance Theater, Paxton took a composition class for dancers at the Cunningham studio taught by musician and composer Robert Dunn, who adapted the assumption-questioning ideas and chance operations of composer John Cage. In response to an assignment to create a one-minute dance, Paxton sat on a bench and ate a sandwich.

“When I wasn’t in the studio my body was just drifting along doing what it did,” he told The New York Times in 2017. “So I started to try to be more aware of what I was doing.”

His first dance, “Proxy” (1961), was made up of poses borrowed from sports photographs and basic tasks like eating a pear, drinking a glass of water — and walking. In his 1967 work “Satisfyin Lover,” he had a large group of people walk across the stage in casual clothes, occasionally stopping to stand or sit. The idea was both avant-garde and populist, breaking down the hierarchies and theatrical heightening of modern dance. It was, he later said, “about looking at what the body does.”

Writing about that work in The Village Voice, dance critic Jill Johnston — who championed the efforts of Judson Dance Theater when most critics dismissed them — celebrated “the incredible assortment of bodies, the any old bodies of our any old lives” — what she called “every postural possibility in the postural spectrum” — and concluded, “That’s you and me in all our ordinary everyday who cares postural splendor.”

Paxton once likened Judson Dance Theater to “a big barbecue, with all the neighbors dropping in.” Members participated in one another’s pieces, investigating what dance was and what it could be. The milieu included visual artists like Robert Rauschenberg, with whom Paxton lived from 1962 to 1967. The two men also took part in each other’s performance works, several of which involved chickens.

Paxton’s dance vocabulary wasn’t always basic. For his 1963 work “Afternoon,” he taught Rainer and other dancers some choreography filled with tricky balances, in the Cunningham vein, but he had them perform it on the uneven terrain of a forest in New Jersey. Rainer later characterized Paxton as her “favorite wily choreographer.”

In 1970, Paxton, Rainer and several other members of Judson Dance Theater started performing together as the leaderless collective Grand Union. The group’s shows were improvisational, anarchic, free-associative.

For Paxton, Grand Union was a laboratory in the possibilities of form and performance. One possibility that he explored further grew into what he called contact improvisation, a duet form in which participants give and take each other’s weight — tumbling, lifting, carrying, falling. The goal, Paxton explained in 1975 in the journal The Drama Review, was to find the “easiest pathways available to their mutually moving masses.”

Contact improvisation can look like gentle wrestling, but it can also be full of surprises, riding the edge of disorientation and risk. (Paxton had been studying aikido.) It was “a form arising from us rather than imposed on us,” Paxton told Dance Magazine. “It’s a game that takes two people to win, so it doesn’t create losers.”

Although contact improv was sometimes practiced in front of an audience, Paxton intended it as both a form of artistic experimentation and a meditative mode of heightening perception and nonverbal communication. For many people, it became a way of life, with a journal (Contact Quarterly) and conferences, classes and jam sessions in many countries. In the mid-1980s, Paxton was not pleased to learn that some people had come to see it as a recreational sport. (“In just 15 years,” he said, “it had gone from an art exploration and a performance thing to a recreation, a dating game.”)

But he moved on to other explorations. From 1986 to 1992, he performed “Goldberg Variations,” a series of intricate improvisations to a Glenn Gould recording of that Bach composition. Beginning in 1986, he developed what he called “material for the spine,” a system focusing on the muscles and sensations of the back, aiming — as he put it in an instructional video — “to bring the light of consciousness to the dark side of the body.”

This was, Paxton explained to Artforum, a return to walking. “What is walking but these bizarre manipulations of the spine?” he asked. “I mean, not odd — they’re normal — but when you look at them there’s more there than you’d expect.”

Steven Douglas Paxton was born Jan. 21, 1939, in Phoenix. His father, Douglas Paxton, was the head of security for a university in Tucson, Arizona. His mother, Katherine (Hamilton) Paxton, was a bookkeeper and an English tutor. He had a brother, David, and a sister, Sherry.

In addition to Nelson, he is survived by his sister.

Before he was a dancer, Paxton was a gymnast. While in high school in Tucson, he accepted a scholarship offered by a dance teacher, thinking that dance classes might be beneficial to his gymnastic skills. Before long, he was performing with local dance troupes.

He enrolled at the University of Arizona but dropped out after one year, having decided, he later told Artforum, that “the most interesting thing to me was dance.” On scholarship at the American Dance Festival in Connecticut in 1958, he came into contact with modern-dance royalty: Martha Graham, Limón, Cunningham.

Limón offered Paxton a scholarship to study with him in New York, and Paxton soon joined his company. But he was more attracted to the experimental work of Cunningham, in whose company he performed from 1961 to 1964.

From 1970 on, Paxton lived at Mad Brook Farm, a commune in Vermont. In older age, he was honored with lifetime achievement awards: a Golden Lion at the 2014 Venice Biennale, a Bessie Award in 2015. Retrospective programs of his work were performed at Dia:Beacon in upstate New York and at the Museum of Modern Art, as part of its 2018 exhibition “Judson Dance Theater: The Work Is Never Done.”

Paxton’s persona was dry, sometimes wry, earning him the nickname Neutral, choreographer Nancy Stark Smith was quoted as saying in a 2014 Times profile of Paxton.

In his later years, Paxton was often treated as a philosopher or a sage. “He is one of the Buddhas of American dance,” Judy Hussie-Taylor, the executive director of Danspace Project, told the Times in 2017.

But Paxton tended to be more humble. In a 2011 video, he equated his attitude toward dance with that of babies just starting to move. It was, he said, “a hunger to find out what movement is or can be.”

This article originally appeared in The New York Times.