Very often we get inquiries that are looking for a massage chair, which must necessarily have a function of weightlessness or zero gravity. Now most massage chairs are equipped with this option, although there are other interesting options. Usually when customers visit the showroom and start testing our zero gravity chairs, they invariably ask the consultant “so, what is zero gravity?”
Origin of the term
This term is used quite often in the massage chair industry because almost all chairs have this feature. But like the terms 3D / 4D massage or L-track and S-track, it is not always immediately clear what it is and what it means. I hope I can shed some light on this terminology below.
According to the Scientific and Technical Encyclopedic Dictionary, the definition of weightlessness is: “It is the state experienced by an object in which there is no action of weight.
And, of course, when each of us imagines a state of weightlessness, we immediately think of an astronaut hovering in weightlessness, who like no other corresponds to the encyclopedic dictionary definition and is in a state “in which no action of weight is manifested” … because the gravitational force is extremely weak in space. Of course, it is obvious that such a state in no way applies to a user who is sitting in a zero gravity chair and who is fully affected by the gravity of planet Earth.
The definition of weightlessness in a massage chair is quite different and is determined not by the force of gravity but by the position of the body in the chair. In this position, the weight of the body is distributed more evenly with respect to the gravitational pull of the Earth. This position can be understood more clearly by referring to the research of the NASA space agency, which introduced the concept of a “neutral position” of the human body in the chair. The term ZERO GRAVITY (weightlessness) was first introduced in the industry massage chairs by American company Human Touch, when they called their chair PERFECT CHAIR, which translates as “perfect chair. According to their website, “the ergonomics of the ‘perfect chair’ are based on the ‘neutral reclining position’ developed by the space agency to support astronauts as they orbit their spacecraft.” This is how the massage industry coined the term ZERO GRAVITY “weightlessness,” which has expanded to the point where virtually every chair model on the market now has this feature.
So, we’ve defined the term “weightlessness” and have broken down how it originated in the world of zero gravity chairs… but, again, what is it and how is this feature built into a massage chair?
Central to understanding this feature, which is designed to prevent and relieve back and neck pain, is the concept of a “neutral position.” This position of a person in a massage chair is a set set of tilt angles that allows the spine to be as relaxed and resistant to stress as possible. This, in turn, reduces pressure on the intervertebral discs, improves blood circulation and relieves soft tissue tension associated with a static resting position.
More specifically, according to the NASA MSIS (Standards for Human and System Integration) development, the angles relative to the spine are 128° (+/- 7°) between the torso and the hip and 133° (+/- 8°) between the hamstrings and the calves. When we are outside of these general degrees of alignment, the spine suffers and the risk of injury increases.
Neutral body position
Many people believe that the “weightless” position involves placing the calves of the legs and feet above the level of the heart. This is not the case. While no one would argue that elevating the feet above the level of the heart is a useful thing, it does not apply to the concept of a “weightless”/neutral body position.
It is often the tilt angle parameters described above that play a role in the positioning of a weightless massage chair. The neutral body position minimizes the effects of gravity on the spine by distributing the body weight evenly. In other words, body weight is distributed in such a way that there are no one or two points on which the maximum body weight falls, let alone an unbalanced distribution of that weight. If you sit on a normal kitchen chair, all of your body weight is transferred to the seat. In the zero gravity or neutral body position, you are in an optimal position in which your body weight is evenly distributed along the entire length of the chair. This is exactly what the massage chair is trying to reproduce.
The zero gravity position in massage chairs
I can tell you that almost all massage chairs try to align the angle of the seat and back of the chair, but I can’t say that they all fully meet the stated parameters. Most weightless chairs have a higher or lower calf-to-thigh angle, the arm-to-shoulder angles are also higher or lower, and the calf-to-shin angle is lower. They are uneven in all directions, but the parameters of torso tilt relative to thighs are usually within the required measurements (taking into account the margin of error). When the massage chair goes into a weightless position, it leans back with the user.
But what about the massage chair feature with 2 or 3-step levels of weightlessness, which is available on some massage chairs? These massage chair positions usually involve even more deviation from the “true” weightlessness position. Such arrangements are nothing special or noteworthy, other than helping you recline even further with the simple push of a button. Such positions are not weightless positions at all. In other words, these extra “weightlessness” settings do not distribute the user’s body weight in the same way as a true neutral body position setting.
Hopefully, the term now makes some sense to you and doesn’t baffle you anymore!