While I’m skeptical of chairs in general, I’ve heard several people with back pain or sitting pain say they get relief by sitting in zero-gravity chairs. I didn’t know what these were, but they sounded cool and I was certainly interested in finding a usable chair, so I started poking around.　　I learned to separate the marketing claims from the actual research upon which they were based, and determine which “benefits” were actually worth getting.　　Full Disclosure: I don’t have a zero-gravity chair, nor (knowing what I now know) do I intend to get one. But if you have one or plan to get one, fear not. The worst danger that is likely to befall you is that you’ll overpay for something you end up not liking.　　What is a zero gravity chair manufacturers?　　While there’s a lot of variation among zero-gravity chairs, in general, they’re designed to support your entire body as you lay back. Many zero-gravity chairs function like recliners, in that they allow you to adjust them into several positions.　　They range from inexpensive, folding lawn chairs to deluxe massage chairs that are destined to stay wherever the delivery person put them.　　Manufacturers and retailers often tout their supposed health benefits, which range from muscle relaxation, to enhanced circulation, to back pain relief. Another frequent claim is that these chairs were influenced by NASA, although the details are rarely given.　　The story of the zero-gravity chair begins, as so many American technology stories do, with the space program.　　The earliest space craft (such as the Apollo capsules I recognize from repeated viewings of Apollo 13) were designed with Earthly constraints in mind. But as people spent more time in space, it became obvious to scientists and the astronauts themselves that bodies in microgravity behave differently than bodies on the ground.　　Astronauts’ spines lengthened, and the curves flattened. They sat taller, since (in additional to their spinal changes) there was less pressure on their butts and heels. Fluids were redistributed through the body, which led to thinner legs and puffier faces.　　One thing that scientists noticed was that people assumed a different posture when they were floating around, free from the constraints of gravity. They didn’t really sit or stand. Instead, they sort of hovered in a relaxed curve.　　Naturally, NASA did some experiments on astronauts to measure their exact position, and published a paper on the topic in 1978. They later included these measurements in standards that specified how spacecraft should be designed to accommodate people.　　It should be noted that the original experiment was performed on 12 astronauts, all of whom were young-to-middle aged, reasonably fit, white men. This selection was entirely pragmatic, considering that the resulting measurements were intended to accommodate other astronauts who would presumably have similar demographics.　　We are portable folding table Supplier, Please contact us if you need.