If you are buying a massage chair and have done a little research, or if perhaps you already own a massage chair and are looking to upgrade, you’ve likely seen various mentions of the “D’s”. This article will help you understand what they mean when manufacturers refer to 2D, 3D, and 4D massage chairs.
Since the very first massage chair and up until fairly recently all available options were 2D massage 
chairs, and most still are. The massage rollers in the back of the chair travel up/down and left/right, to create the rolling and kneading massage motions. In some massage chairs, you can also adjust the width and speed of the rollers (left/right, wide/narrow, fast/slow), but the massage movements in 2D massage chairs remain on one flat plane in 2 dimensions.
Recently premium massage chairs have added the ability to extend the rollers into your back and retract them back into the chair. These are 3D massage chairs, and they provide the deepest massage since 
they can press into your back, just like a massage therapist would.
So in addition to up/down and left/right, 3D massage chairs go in/out – this is the third plane of motion. This allows more control over the depth of your massage and will feel more like a human touch. 3D massage chairs will allow you to fine-tune the massage from soft to deep tissue depending on the depth the rollers can extend into your back. This depth can range from 2.2 inches on some models to 4.7 inches on others. The body scanning ability of 3D chairs (ability to determine your shape, size, height) is also much more accurate and precise than scanning in a 2D massage chair.
So what the heck is a 4D massage chair?
You may have seen this advertised on some massage chair websites, and it sure sounds pretty awesome. They state that the chair operates with 3D motion and you can adjust speed which is the 4th “D” but all massage chairs can adjust the speed so that doesn’t make any sense. Einstein postulated the 4th dimension as “time”. So these “4D” chairs will go up/down, left/right, in/out….and….forward in time. Unless you are using your massage chair in a science fiction movie, or really close to a black hole, all massage chairs (and everything else in the universe) travels forward in time. So you could say there’s no such thing as a “4D” massage chair, or all 3D massage chairs are also 4D.
True 4D on the other hand is a 3D massage chair that is also an L-Track or a chair that can massage your back and your bottom. So the 4th “D” is pushing up on your gluts and hamstrings. These chairs are pretty rare as the tech is new and some don’t do it very well but the Brio by Positive Posture is the best there is. Technically these should just be called “3D L-Track” but 4D sounds cooler.
If you see a massage chair advertised as “5D”, and will allow you to travel back in time, we’d love to try it out. In the meantime, I’d get a Brio.
