A real ergonomic chair allows adjustments to the height, backrest angle, armrest position, as well as seat depth matching your body’s proportions. This personalizing makes of the chair a truly ergonomic one.
Since everyone's body differs in height, leg length, and shoulder width, a chair of one-size-fits-all cannot properly support everyone. Ergonomic chairs have adjustability in key areas because of that. The seat can be lowered or raised so feet sit flat upon it. The tilt of the backrest is adjustable. Therefore, one can avoid leaning forward. For comfort, the armrests are adjustable. Shoulders have a chance to remain relaxed when they are properly set up.
A big impact comes about from these small changes now. With them, your joints and muscles feel less strain, specifically through longer sitting sessions. Your body is helped by, instead of fought by the chair.
The answer is simple, if you ask just what makes any chair ergonomic it is just a chair that’s designed for your body. It is not just only a chair that is designed for the purpose of sitting.