What's a zero-gravity massage chair?

The Human Touch HT-7450 Zero-Gravity Massage Chair in full recline mode. See more pictures of essential gadgets.
Courtesy Amazon

It's story time! Imagine a weary, aching journalist walking through an enormous showroom at the 2008 Consumer Electronics Showcase in Las Vegas. This poor fellow spent the last several hours looking at countless gadgets and displays. By the end of the day, the writer just wants to get back to a hotel room and collapse. But then something catches his eye. It's the Human Touch HT-7450 Zero-Gravity Massage Chair, a recipient of a 2008 Innovations Design and Engineering award.

Being a dedicated journalist, the writer knew it would be irresponsible to leave the showroom floor without giving this machine a thorough test run. So he set down a bag of press kits, removed his shoes and took a seat on the award-winning chair. His legs snuggled into two concave indentations on the leg rest. His head settled against a cushioned head rest. A helpful booth attendant gave him a smile and pressed a button on a remote control. The chair immediately began to recline.

Users can control the HT-7450 with a remote control. Users can control the HT-7450 with a remote control.
Users can control the HT-7450 with a remote control.
Courtesy Amazon

And it continued to recline until the writer's legs were higher than his torso. He experienced an odd sensation -- it felt almost as if the chair would dump him on his head. Perhaps he had fallen prey to some sort of torture device designed to punish weary convention visitors. But worries soon melted away. And along with them went the tension and stiffness accumulated after walking for miles along aisles of electronics.

The massage chair used rollers, air bags, heat pads and vibrating surfaces to ease his aches and pains. The massage routine lasted for several minutes before returning him to an upright (but very relaxed) position. The journalist put his shoes back on, picked up his bag of press kits and made his way back to his hotel.

While Human Touch says the HT-7450 as the world's first zero-gravity massage chair, other manufacturers offer their own zero-gravity models. But what is it that makes these massage chairs zero-gravity? Do they hover? Do they provide the user with a sense of weightlessness? Is it just a clever marketing gimmick? We'll find out in the next section.

The Zero-gravity Position

Not all zero-gravity chairs are massage chairs.
Not all zero-gravity chairs are massage chairs.
Courtesy Amazon

Let's cut to the chase: The chair doesn't defy gravity. Even with all the massage elements running and in full recline, you're not going to fly off into the atmosphere. Nor does the chair hover, float or even lose weight. In fact, according to the user's manual, the chair weighs 200 pounds (90.7 kilograms) [source: HT-7450 Manual]. So what does it mean if a massage chair is a zero-gravity model?

­It has to do with the recline position the chair can assume. The position mimics the posture astronauts take during liftoff on space missions. Because astronauts endure intense and sudden increases in gravity while escaping the Earth's gravitational pull, it's important that they position themselves so that their bodies can deal with the increase in stress. By assuming a reclined position, astronauts distribute the stresses of takeoff across their bodies in a safe way. To that end, the chairs astronauts sit in during launch use this reclined configuration.

An astronaut sits in a spacecraft simulator in the zero-gravity position. An astronaut sits in a spacecraft simulator in the zero-gravity position.
An astronaut sits in a spacecraft simulator in the zero-gravity position.
Courtesy NASA

Zero-gravity massage chairs can assume the same position to help distribute a user's weight across the chair. The manufacturers claim that this relieves stress on the body and allows for a deeper, more intense massage experience. Some manufacturers claim that the reduction of stress on your body is so effective you'll feel virtually weightless as a result.


­While several massage chair manufacturers offer models that come with the zero-gravity position feature, not all zero-gravity chairs are massage chairs. Some furniture manufacturers offer normal chairs that recline into the zero-gravity position. The chairs distribute your weight and support you, but they won't rub away your tension and stress.

Other manufacturers stop short of making that particular claim. Instead, they say that the chair replicates the launch chairs for astronauts. They call their chairs zero-gravity not because of the effect the user feels, but because of the position the chair assumes when activated.

One benefit of this position is that it promotes circulation in the legs and reduces swelling. Elevating the legs over the level of the heart during rest can help prevent conditions like varicose veins [source: VascularWeb]. Of course, you could achieve the same effect by lying down and putting a couple of pillows under your legs. But that's not quite as impressive.

During the author's massage experience -- yes, the author was the weary journalist mentioned earlier -- there was no sensation of weightlessness, but the reclined position was comfortable and did allow for an intense massage. Because the author's back was in full contact with the chair's backrest, the full force of the chair's massage routine was effective. An upright position might not allow the intensity and thoroughness of a massage in the reclined position.

Are zero-gravity massage chairs worth the expense? That's a decision best left to the consumer. Some people might think the chair's convenience and effectiveness makes the expense completely justifiable. Others might prefer to see a human massage therapist -- $4,000 could buy a lot of visits to the spa.

To learn more about massage chairs and related topics, take a look at the links on the next page.

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More Great Links


  • Human Touch. http://www.humantouch.com
  • Human Touch. "HT-7450 User's Manual." http://lib.store.yahoo.net/lib/humantouch-com/HT-7450-usermanual.pdf
  • Sanyo. http://us.sanyo.com/appliances/massage_chairs/index.cfm?productID=1480
  • Smith, S. E. "What is a Zero Gravity Chair?" WiseGeek. http://www.wisegeek.com/what-is-a-zero-gravity-chair.htm
  • VascularWeb. "Varicose Veins." http://www.vascularweb.org/patients/NorthPoint/Varicose_Veins.html