Types of headrests. How to choose a headrest in a chair?

Main Feature: The 1D (one-dimensional) headrest provides support in one, but the most crucial, plane - vertical. This is a basic element necessary for any chair focused on prolonged sitting.

Functionality and Details:

Height Adjustment: The user can easily raise or lower the headrest, typically within a 3–5 cm range. The goal is to ensure the headrest supports the curve of the neck (cervical lordosis) and the back of the head, rather than simply resting on the shoulders.

What it Adds (Ergonomic Advantage): The 1D model provides basic support for the cervical spine, allowing the muscles to relax when leaning back. This is critically important for reducing muscle tension. Compared to a chair without a headrest, even this simple support prevents excessive backward tilting of the head, helping to avoid "computer neck syndrome" during moments of rest.

Key Feature: The 2D (two-dimensional) headrest adds a second plane of adjustment — the tilt angle (or depth). This allows the user to more precisely customize the contact surface.

Functionality and Details:

Height Adjustment: Remains for accommodating individual user height.

Tilt Angle Adjustment: Allows the headrest pillow itself to be tilted forward (towards the head) or backward. The range is typically $30^\circ$ and more. This mechanism helps ensure firm contact with the neck and head regardless of how far the chair's backrest is reclined.

What It Adds (Ergonomic Advantage): In addition to the basic height, the 2D headrest offers the configuration of the desired contact depth. This allows it to compensate for the backrest's tilt angle and ensure the neck is correctly supported, even if the user is sitting upright. This is a significant step forward for ergonomics, as the head does not have to "search" for support.

Key Feature: The 3D (three-dimensional) headrest introduces a third, often crucial, dimension — the horizontal reach (depth), or the distance from the backrest.

Functionality and Details:

Height Adjustment

Tilt Angle Adjustment

Depth (Reach) Adjustment: This is the ability to mechanically slide the headrest forward or backward. Unlike the tilt (2D), this function changes the overall distance from the backrest to the headrest, typically within a range of 5–6 cm.

What It Adds (Ergonomic Advantage): The third axis allows a user with any neck length, shoulder width, or sitting posture to perfectly set the distance. This is especially important for taller individuals or those using a chair with deep seating. The 3D headrest completely eliminates the "empty space" between the head and the chair, ensuring constant and stable support, which is the standard in high-quality office chairs.

Key Feature: The 4D (four-dimensional) headrest is the most advanced, as it includes all previous functions and adds a fourth dimension, which is dual, independent tilt angle adjustment. This allows for a more precise selection of the neck support angle.

Functionality and Details:

Height Adjustment

Depth (Reach) Adjustment

Tilt Angle Adjustment (2D): This functionality is expanded, dividing into two independent mechanisms:

Tilt 1: Adjusting the tilt angle of the headrest holder/bracket (as in 2D).

Tilt 2 (4th Dimension): Adjusting the tilt angle of the headrest cushion itself, independently of the holder.

What It Adds (Ergonomic Advantage): The dual tilt adjustment is the key to extremely precise support for the cervical lordosis (curve) in any posture.

As you recline, the holder can tilt to follow the chair's movement. And then, you can finely tune the cushion itself to rest comfortably against the back of your head, without pressing or leaving a gap. This ensures the neck is in a neutral position, completely relieving muscle strain and providing full relaxation and recovery during long breaks. 4D systems provide complete ergonomic personalization.