Modern Massage Chairs Explained

If you’re in the market for a modern massage chair or are checking out massage chairs for the first time ever, you’re probably confused by some of the descriptive terms which are used as selling points. There’s tons of acronyms and different terms used by different manufacturers which are ultimately used to describe the same thing. Here we will go over not only what the terms mean but also which terms are synonymous and interchangeable so that, the next time you’re looking for a new chair, you can do so with confidence.


Zero gravity is a term which is included in many modern massage chairs and basically refers to the extent and position to which a massage chair can recline. Older massage chairs typically went back to about 150 degrees or as far as an ordinary living room set recliner and, while this was comfortable and great for the time, zero gravity massage chairs take things one step further. Zero gravity massage chairs recline all the way back leaving the body in a neutral, lying position and also allow for knees to be raised above the heart. Having the knees raised above the heart is said to improve circulation and reduce the stress load on the heart. Additionally, having a chair which can recline this far back relieves pressure on the upper and lower back as well as the pelvic region. For these reasons, zero gravity is a highly sought after feature in modern pedicure chairs.


To understand SL track massage chairs, you should first understand the terms S track and L track. S track massage rollers get their name from their shape which is literally like an “S” in order to accommodate for the natural curves of the spine; especially in the neck and lower back. L track massage chairs are like an extended version of the S track massage chairs in that they have the same curvature in the upper part of the massage rollers for the neck and lower back but also extend further down to the buttocks. Finally, an SL track is really just a synonym for L track massage chairs in that SL track chairs have the same curvature in the rollers for the neck and lower back and also extend to the buttocks. Ultimately, the increased use of the “SL track” term as opposed to the “L track” term may be a simple marketing tactic in which people who do not know the difference believe that SL tracks are somehow superior because of the implication that they are a combination of both the “S” and “L” track into one chair.

3D, 4D, 5D

You will likely see the terms “3D,” “4D” and “5D” (and maybe 6D, 7D or 8D) used in the descriptions of modern massage chairs and it is natural to intuit that the higher the number, the better the feature. However, this is not really the case. Ultimately, the only genuine descriptor is “3D” because this feature refers to the rollers of the massage chair having the ability to change their depth in addition to simply moving up and down and from side to side. Therefore, as there are only three geometrical dimensions (height, length and width), it is impossible for a 4D or 5D chair to be better than a 3D chair because this would imply that the chair’s rollers are able to move in more dimensions than actually exist.  


All of these terms, which are sometimes used interchangeably, refer to chairs which have features to gently pull either the upper and lower parts of your legs or your entire body in opposite directions to relieve physical tension. Many chairs use a type of inflatable pillow to achieve this feature wherein the action of the pillow being inflated in certain parts of the chair creates a gentle, kinetic pull on parts of the body.


Many modern massage chairs have smart scanning systems to detect where your body is and how the massage chair can best accommodate your unique body shape. This is useful so that, a shorter person lets say, isn’t getting the top of their head massaged by the neck rollers simply because the chair doesn’t alter its mechanisms based on the persons size. The descriptions of automatic body scanning systems, much like with rollers, are sprinkled with marketing terms like “4D” or “5D” which are ultimately meaningless. Again, the world only exists in three dimensions so any body scanning technology on a massage chair can only scan your body in three dimensions (3D).


Hopefully this article has cleared up some of the confusion you may feel about the more ambiguous terms you see when looking for a new massage chair.  The other terms which you will likely run into such as the number of preset massage functions, voice activation or whether or not the massage chair is heated are more self-explanatory and you shouldn’t have any trouble understanding them.