When it comes to massage chairs, it's what's on the inside that really counts. And if you've done any research, you've probably come across specific terms to describe the different massage technologies behind the scenes.

Two of the most common questions we're asked about are L-Track vs. S-Track designs and 2D vs. 3D/4D technology.

First, Massaging back nodes are called Rollers

Inside every quality massage chair, you'll find rollers on a track in the back. Some tracks extend further than others – the longer the track, the more massage coverage the user receives. Very inexpensive chairs will have rollers but no track. They are fixed. These types of chairs create gaps in coverage, are ineffective, and sometimes painful. They should be avoided. Always look for a track that allows the massaging robot to travel up and down the back.

Most massage chairs offer a selection of massage techniques — like kneading, Shiatsu, tapping and knocking — that are carried out through the rollers. The length to which the rollers travel down your back is determined by the type of track in the massage chair, while the intensity and movement is determined by the technology.

S-Track vs. L-Track Massage Chairs

The design of the back roller track varies from chair to chair, but will likely be categorized as either an S-Track or an L (or SL) Track massage chair.

S-Track Massage Chairs

The S in S-Track stands for "sinusoidal", which is just a fancy way to say "wave". These roller tracks follow the curve of the spine, moving up and down from the neck to the lower back. S-Track massage chairs will allow you to lay out flatter or even slightly inverted, for superior stretching performance that is sometimes called Thai massage.

L/SL-Track Massage Chairs

L-Track massage chairs work the same way as S -Tracks but extend further down the body. The L-Track can travel down around to your glutes to the top of the hamstrings. L-Tracks cover more muscle groups for a more complete full body massage.

Which Track is Better?

It depends. If you want your massage chair to excel in stretching your back for the best possible spinal decompression, an S-Track is the only way to go. However, an L-Track will provide a more comprehensive full body massage and a superior zero gravity position that also helps with spinal decompression. Most people will choose an L-Track for this reason. If you're looking for a massage chair to help your lower back, hamstrings, and glutes, an L-Track is your best option.

2D vs. 3D/4D Massage Chairs

Back mechanism roller technology is continually evolving so that massage chairs feel more like your own personal masseuse than a machine. Even in the last few years, the technology has grown light-years from basic 2D to 4D. Here's an overview of your options:

2D Massage Chairs

2D massage chair rollers move in two dimensions: up & down and side to side with a fixed depth otherwise known as intensity. You might see this referred to as the rollers working on X and Y axes. 2D technology is less expensive and a great place to start for a 1st chair purchase, if on a budget.

3D/4D Massage Chairs

Where a 2D massage chair works on X and Y axes, 3D chairs run on the X,Y and Z axes. This provides the 3rd dimension of movement so you have up & down, side to side and in & out movements. When you see the term 4D this means the 3D mechanism moves are varying speeds to truly mimic the motions of a human massage. The third dimension of in & out also allows the user to change the level of intensity.

Turn up the 3D and the rollers are able to push out further, deeper into your back. This means a 3D/4D massage chair grows with you over time as your body becomes accustomed to deep tissue massage and craves deeper intensity. You can adjust the intensity level of the rollers from very gentle to deep tissue. 3D/4D massage chairs are great for homes with multiple users, since everyone can easily find the perfect intensity level for their personal preference.

Which Technology is Better?

For a human-like, personalized massage, a 3D/4D massage chair will be your best bet.

Zero Gravity

Zero gravity massage chairs use a reclining position to evenly distribute body weight. Since zero gravity distributes your weight throughout the massage chair, there will be less stress placed on certain parts of your body, such as your spine and neck. As your muscles relax in the zero-gravity position, you may also experience a feeling of weightlessness. Zero gravity chairs, therefore, promote relation and spinal decompression. And with your feet elevated above your heart, you also benefit from improved circulation.


Inversion massage chairs recline back below a horizontal level, to just below 180 degrees on an S-Track. This technique reverses normal gravitational forces on every part of your body, with your head down and your heels up. Inversion therapy helps spinal correction using gravity to gently decompress the spine, bringing additional relief to people with back pain.

Purchasing a massage chair involves a lot of decision-making, and we're here to help you make the right choice.