2D, 3D, 4D and 6D are an example of some nifty jargon that you see in the ergonomic office chair world but it is often not explained which makes the constant reference to it quite unhelpful. It simply refers to the number of dimensions in which the armrest can be adjusted. As a general rule of thumb, provided the build quality is good, the greater the adjustability the better.
So when we are looking at a 6D armrest, the adjustments which will be available are:
height: to raise or lower the armrests depending on your body height, most basic function in an armrest.
pivot or rotation inwards or outwards: great function if you are doing a lot of work on computers and also for gaming as it helps your forearms to be continually supported as you type or use your mouse by finding the most natural and comfortable.
adjustment in or out to increase or decrease the width: excellent function to have for people with broader or narrower shoulders to the norm to help their arms rest comfortably in a vertical line down from your shoulders.
adjustment forward and back: to position the armrests closer to or farther away from the seat permitting a greater range of activities.
depth: to position the armrests closer or farther away from the body to tailor different arm lengths and preferences.
angle: to tilt the armrests inward or outward for additional support and comfort
In our view, most users will get more than enough performance for their needs from a 3D armrest, as the forward and back adjustment in our view is of limited appeal to most, provided that the chair is otherwise set up well. The SIHOO Doro C300 is a great ergonomic office chair available in the UK with 3D armrests. For a full 6D armrest experience, we recommend the ultimate ergonomic office chair SIHO Doro C300 Pro.
When it gets to 2D armrest, it is actually quite important to double check which of the two dimensions of adjustment are being offered so that you in fact get what you think you need
When it comes to modern ergonomic office chairs, it is important to make sure the armrests adjust to all the positions that you need. The SIHOO M102C for instance offers 2D armrests with flip-up armrests that can move back and forth and pivot left and right, offering support to your arms and elbows as you work and letting you lower the armrests to push the chair under the desk once your are finished.