The Chair

Key Points

  • Your workstation needs to be built around your chair

  • Your chair should have adjustments and as many adjustments as possible

  • Your chair needs to be fitted to your body type

  • Research suggests your chair should have a back rest

Choosing the Chair

The chair you choose is your chair and only your chair. It needs to be the focus of your workstation and ideally, everything else is built around it. This includes the desk, monitor, input devices (keyboard, number keyboard, mouse), etc. It should have a back rest, which allows you to sit for as long as possible before fatiguing (this is the purpose of the chair).

Quick Question: Have you ever been in the situation where you have the perfect chair for your workstation and then one day it mysteriously disappears? You notice that your chair was swapped out for another. Frustrated, you want your chair back. So what do you do? You set off to find your chair. After some searching, you find it. You switch it out for the other you had. Restored, you now sit; although something’s wrong. It’s been adjusted. Now you have to readjust it. After a moment of readjusting the various components, you can finally sit. Now you can work comfortably.

How do I choose the best chair

The Checklist to choose the best chair:

  • Back rest?

  • Lumbar support?

  • Adjustable arm rests?

  • Adjustable chair height?

  • Waterfall seat pan design?

  • Adjustable forward/backward seat pan slide?

  • Tilting seat pan function (up/down)?

  • 5 legs with caster wheels?

 Anatomy & Adjustments of your Chair

Other Important Adjustment Considerations

  • Waterfall front design:

    • Decreases sharp abrupt corner behind your thighs

  • Seat pan tilt function:

    • Important for:

      • Opening up the hip angle

        • i.e., Pregnant women

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Chair Fitting

It’s always a good idea to have an experienced professional assess your workstation. Such a person is called an ergonomist. If you need an ergonomist, you can search for a local ergonomist in your area. They typically have a certification of CEAS-I, which stands for a certified ergonomics assessment specialist. When and if you contract the services of an ergonomist, you can expect a few things from them: an interview, an observation of your workstation and a write up of their assessment with recommended changes. These changes are intended to optimize your set-up and minimize most work related musculoskeletal disorders.

If you’re interested, I happen to be certified as a CEAS-I and will be happy to discuss your options and assess your workstation. Click on the image to the right to inquire.

Research on the Backrest

Curran M, O'Sullivan L, O'Sullivan P, Dankaerts W, O'Sullivan K. Does Using a Chair Backrest or Reducing Seated Hip Flexion Influence Trunk Muscle Activity and Discomfort? A Systematic Review. Hum Factors. 2015 Nov;57(7):1115-48. doi: 10.1177/0018720815591905. Epub 2015 Jul 14. PMID: 26175544.

  • Summary: 26 randomized controlled trails were included for analysis in this systematic review. Moderate evidence was found to support that there is less paraspinal muscle activation when using a backrest and there is limited evidence to support the use of a backrest or reducing the seated hip angle in lowering back pain.

De Carvalho D, Grondin D, Callaghan J. The impact of office chair features on lumbar lordosis, intervertebral joint and sacral tilt angles: a radiographic assessment. Ergonomics. 2017 Oct;60(10):1393-1404. doi: 10.1080/00140139.2016.1265670. Epub 2016 Dec 23. PMID: 27915585.

  • Summary: 28 participants were radiographed in 4 chair positions: control, lumbar support, seat pan tilt and backrest with scapular relief. There was no difference found in lumbar flexion but lumbar support produced significant anterior pelvic rotation and the seat pan tilt position significantly improved pelvic posture.

 Take Home Messages

  1. There needs to be better clinical studies to arrive at a definitive conclusion of sitting systems. But, is is clear that backrests offer a rest for your back to allow you to sit for longer periods of time when seated.

  2. Sitting without a back rest only encourages lumbar flexion and we know prolonged lumbar forward bending is bad for your disc and the structures behind your disc. Hint: the lumbar nerves.

  3. Get up, stand-up and move often. A good rule of thumb: every 15-30mins. This is also known as an ergonomic break.

  4. The opposite of sitting is walking.