Ropes haven’t always been used on humans for the happiest purposes. Hanging, kidnapping and trussing to railroad tracks come to mind. So when I enter the recently opened Peak Physical Therapy Sports & Performance Center in Williston, it occurs to me that the so-called “health center” might be a euphemism for something kinkier. Sure, the facility has deadweights and a smoothie station, but pulleys dangle from racks in the ceiling, and through them snake red ropes, bungee cords and slings.

Turns out this is decidedly not a Fifty Shades of Grey-themed bondage dungeon. The suspension lines are part of a Norwegian fitness system called Redcord that’s making its debut in Vermont. And, while they’re not torture contraptions per se, they can make for grueling workouts.

Susan Dodge, a physical therapist and the owner of Peak, used to operate her business in South Burlington under the name Povlin Performance. She bought the Williston space last September and had settled into it by November along with two other businesses: Whole Health Nutrition and Pure Energy. By operating under the same roof, Dodge says, they aim to serve as an emporium of health and wellness services, or a “clinical spa.”

“Most of the services we provide are billable to insurance companies, with the exception of the performance training piece,” Dodge says. “So it’s a little different than if you go to a health club or a traditional spa, because you’re paying out of pocket for most of those services. We’re trying to bring our arms around our clients and really have all their needs met in one setting.”

This Thursday, January 23, Peak will hold an open house to introduce the public to its offerings, which include food, massage and mindset coaching. But Redcord is bound to turn the most heads.

The system was devised in 1991 by Petter Planke, a Norwegian who had experienced severe back pain for two decades. He finally jerry-rigged a rope-and-pulley system to provide traction while he did exercises.

Now Redcord can be used for both physical therapy and personal training. When I go in, personal trainer Betsy Bluto shows me a few of its applications. First we do planks, an exercise in which you lie prone and prop yourself on your elbows, keeping your body straight as a board. For the Redcord version of the exercise, Bluto wedges my feet into a sling hanging a foot off the ground.

“You’re going to come up the same way you would with your feet on the floor, so, contracting your core, come on up,” she instructs me. “Can you feel the difference?”

“It’s more of a workout,” I agree with a groan.

“Absolutely,” Bluto remarks as I collapse to the floor. “You’re in suspension, so your feet are not in a fixed plane. They’re up in the air, so how that translates into your body [is], your core has to work a little bit harder.”

As I flounder through each exercise, Bluto adjusts the difficulty by changing the length and arrangement of the cords. To make planks easier, for example, a sling could be placed under my midriff, supporting me in midair like Tom Cruise in Mission: Impossible. At the end of the session, Bluto shows me how to simulate cross-country skiing by doing lunges with one foot in the sling.

The science behind Redcord is known as Neurac, or neuromuscular activation. It helps users pinpoint and treat their muscle problems in a way that traditional, one-dimensional strength training doesn’t. Bluto, who rides horses, says the system helped her when she was having trouble keeping her right foot under pressure in the stirrup. Her physical therapist at Peak — Neurac-certified Kristina Marcussen — used the suspension system to diagnose and treat her weak gluteus medius.

Marcussen’s certification is no anomaly. She holds dual citizenship in Norway and the U.S., and her father comes from the same town where the technology is produced. After growing up in Essex, Vt., she pursued a doctorate in physical therapy and later trained under Neurac’s vice president of curriculum development.

In 2008, Marcussen and several other Neurac disciples tried to start a clinic of their own in Santa Barbara, Calif., but the economic meltdown thwarted their effort. Redcord has slowly been gaining ground around the world, though; according to Marcussen, it is now used in 38 countries.

Norwegian golfer Suzann Pettersen has endorsed Redcord, and several studies have shown the efficacy of comparable suspension systems. In one notable study, a group of junior golfers working on their swings was divided in two. One group used traditional strength training, while another used a Redcord-like set of slings. The latter half ended up hitting the balls with twice as much velocity as the control group.

Neurac’s real scientific breakthrough took place a dozen years ago, Marcussen explains. In 2002, a thirtysomething Norwegian who had never been able to lift his arm above 90 degrees owing to a birth injury enrolled in a Neurac program.

“Over the course of two days, he kind of contradicted all his beliefs in physical therapists, and he decided to push it harder. By the end, he was able to lift his arm over his head,” Marcussen says. “We went back and really looked at the neuromuscular system, and how pain affects how and what muscles we use. If you have pain, your brain really turns on a different motor pattern.”

By placing people in suspension — what Marcussen describes as a “closed kinetic loop” — the system has made it possible for individuals to stimulate muscles that may have seemed irreversibly damaged. When Peak hosts its open house, individuals will have the chance to try that “weak link testing.” Gung-ho fitness junkies will be able to see how many reps of certain exercises they can do with Redcord, compared with conventional methods.

For Dodge, who says she has adopted a holistic business model, there is clear utility in a rehabilitation program that stimulates the body from every angle. “It’s more functional. You’re not just doing isolation exercises,” she says. “We function in the world in three different planes of motion, and traditional exercise is really only looking at it in one plane.”

Peak Physical Therapy Sports & Performance Center hosts an open house on January 23, 8 to 10 a.m. at 20 Wintersport Lane, suite 155 in Williston. Info, 658-0949.

The original print version of this article was headlined "Learning the Ropes"