Chair mechanisms: synchro, tilting and permanent contact

05/11/2025 · FactoryOficina

Home › Blog › Ergonomics

Chair mechanisms guide: synchronous, tilt, permanent contact

Understand how each office chair mechanism works, its pros and cons, when to choose one over another, how to set them up properly, and indicative price ranges. If you’re renewing workstations, also compare refurbished versus new options.

1) What each mechanism is (plain explanation)

Permanent contact (PC)

The backrest tilts and “follows” your back with adjustable resistance; the seat usually stays fixed. It may allow locking the backrest tilt in one or several positions.

Tilt

Seat and backrest tilt together around a pivot, keeping the angle between them. It usually offers tension adjustment, 1–4 lock positions, and an “anti-kickback” function.

Synchronous

Seat and back move together but at different rates (e.g., 2:1). It helps keep the pelvis stable while the backrest supports your spine. It typically offers multiple locks, tension control and, on ergonomic chairs, seat depth slider and lumbar adjustment.

2) Pros and cons compared

Type	Pros	Cons	Best for
Permanent contact	Low price, simple mechanics, easy to use.	Fewer adjustments; seat is usually fixed; not ideal for long shifts.	Occasional desks, waiting areas, light home office.
Tilt	Pleasant rocking, lock, adjustable tension.	Seat-back angle doesn’t change; can “press” thighs for shorter users if tension is stiff.	Standard office 4–6 h/day, meeting rooms.
Synchronous	Better 8-hour ergonomics: maintains lumbar support, reduces thigh pressure; more adjustment points.	Higher price; requires proper tension and seat-depth setup.	Intensive use, daily remote work, users with lumbar discomfort.

3) Which one should I choose for my use?

Occasional (≤3 h/day): PC or simple tilt with lock. Prioritise an affordable chair that’s stable.
Standard (4–6 h/day): tilt with high back and 2D arms; if you can, step up to an ergonomic synchronous.
Intensive (7–8 h/day): synchronous with seat depth slider, adjustable lumbar and 3D/4D arms. Consider certified models.

On a tight budget? Refurbished can be up to 70% cheaper than new, with inspection and cleaning. At FactoryOficina the warranty is 1 year on refurbished and 3 years on new.

4) Adjustments and common mistakes

Tension too stiff (shoulder fatigue) or too loose (you “fall” back). Adjust the knob until you can recline in control, without effort.
Seat height set wrong: aim for 90–100° at the knees and feet flat on the floor. If the front edge touches the crease, raise the chair or use a footrest.
Seat depth slider (if present): leave 2–3 fingers between seat edge and knee crease.
Always locked: working permanently locked removes micro-movement. Alternate between lock and free-float during the day.
Armrests too high: they lift the shoulders and strain the neck. Adjust so elbows rest without pushing the shoulders up.
Lumbar: place it where you feel support on the lumbar curve, not on the ribs.

Complete the workstation with a suitable desk; if you alternate postures, consider height-adjustable desks.

5) Approximate price and what to check on the product page

Indicative in Spain (2025); depends on brand, upholstery, certifications and armrests:

Refurbished:
- Permanent contact: ≈ 70–140 €
- Tilt: ≈ 80–200 €
- Synchronous: ≈ 120–400 €
New:
- Permanent contact: ≈ 80–170 €
- Tilt: ≈ 120–250 €
- Synchronous: ≈ 170–1000 € (premium ranges above)

What to check: mechanism type, number of locks, tension control, seat depth slider, lumbar, arms (1D/2D/3D/4D), back height and stated warranty.

6) Frequently asked questions (FAQ)

What’s the most ergonomic mechanism for 8 hours?: Synchronous, due to the coordinated 2:1 back-to-seat movement and extra adjustments (seat slider, lumbar, multiple locks).
How do I know if my chair is synchronous?: Recline: if the back moves back more than the seat and the hip angle opens, it’s synchronous. On tilt, both move together as one piece.
Are 3D/4D armrests worth it?: Yes for intensive use: they help align elbows and wrists to the keyboard, easing shoulder tension. For occasional use, 2D is usually enough.