One size does not fit all
Chairs, like spines, come in all shapes and sizes so choosing the perfect chair depends very much upon the user.
After the perfect sized chair has been identified there are still a myriad of other issues with which to contend in order to make the most of the features available.
A chair has to provide more functions than just being comfortable. In today’s ever-sedentary population posture is becoming more and more important. If you or your staff sit for long periods your body can suffer through postural issues such as lower back pain, trapped nerves and headaches.
By investing in office furniture that can support your spine, the savings can easily justify the cost. Workplace injury and illness costs the UK economy £14.2 billion per year and in 2013/14 525,000 workers were suffering with a work-related musculoskeletal disorder (WMSD). For a small one-off cost many postural issues can be minimised or avoided altogether.
In offices worldwide standing or sit-stand desks are becoming more and more popular, with the UK being left behind. Although the benefits are clear with regards to enhanced posture, increased productivity and elevated calorie burning, they aren’t for everyone and can be cost-prohibitive. Here at Office Osteopaths we recommend that our clients ensure their staff stand for a minimum of 2 hours a day in keeping with recommendations from the British Heart Foundation, but at the very least keep moving during the working day.
As such, making the right choice of chair can be tricky, so here’s our guide to making the most of your investment.
Central spine / adjustable arm rests
In order to be able to move close enough to the desk to minimise the strain on the upper back and neck, the height of the arm rests often need to be adjusted. On cheaper models of chair the arm rests are locked in place by supporting the back rest. They are unadjustable and by removing them the back falls off leaving you with an expensive stool.
Adjustable seat pan
To disperse the weight of the body across the legs comfortably, the legs must be supported. By having a seat pan that contacts the entire length of the femur (thigh bone), the pressure of the torso is dissipated efficiently and not focused on just the upper femur. Ideally the seat pan must be no more than 2 inches from the back of the knee at the pan’s furthest lockable position.
Mesh back rest
Much like hiking bags, mesh back rests provide support and comfort without allowing sweat build-up. Mesh backs increase the airflow to the area so condensation is evaporated more easily, increasing comfort. They are also easier to clean and are harder wearing, meaning they can last longer and don’t degrade to looking old and worn.
Namchensen (1981) studied lumbar disc loading and found that unsupported sitting increased the pressure on the lumbar discs by up to 40% (using standing straight as the 100% benchmark). This is thought to be because of the lack of support for the lumbar discs from the core muscles.
Recommended sitting guidelines from the HSE state that chairs should tilt from 90 degrees to 110 degrees, depending on the user and any pre-existing conditions.
Last but by no means least is the most crucial function of a good chair that ensures that the lordosis (lumbar curve) is maintained. Without a lumbar support the lordosis can be flattened, placing more pressure on the discs of the lower back. A good support maintains the natural inward curve, reducing the pressure and preventing back pain. As we all have different heights and therefore different lumbar curve lengths it is an advantage to have an adjustable lumbar support. Supports can, however, be bought separately at a reasonable price to enhance existing office chairs so it’s not the end of the world if the recently purchased office-wide chair model came without one.
We’ve left certain things out on purpose, such as adjustable height, because hopefully that would be a given on any chair and no employer would give their staff a locked chair to sit on. In the same way, we have left out head and neck rests because they’re only useful for users who want to sleep at their desk and we doubt that many employers would encourage them (although there’s evidence they should).
Some manufacturers like Herman Miller, Humanscale and Steelcase offer chairs which are composed of a large propeortion of recyclable materials. This is an important feature if your company has an environmentally friendly office culture.
For the perfect chair it is possible to customise chairs for each and every staff member (if the budget allows of course). By taking individual measurements some manufacturers can create bespoke products for all shapes and sizes of employees.
Remember, a chair is only as good as the setup, so it is important to get the experts in to alter each one individually. Many offices use a video that staff have to sign off to say they’ve taken responsibility for their own workstation assessment. However, that doesn’t give them the objective perspective that the ergonomically-qualified can provide. As such if it is ineffective the potential risk of back and neck pain remains very real and the potential saving that the amazing chairs purchased could provide is wasted.
Call us on 0118 380 0385 or email us on contact@localhost/officeosteopaths to discuss how we can help.
HSE Workstation Guidelines (free ebook): http://www.hse.gov.uk/pUbns/priced/hsg57.pdf
Disc Pressure Measurements (Namchensen 1981 ): http://www.ncbi.nlm.nih.gov/pubmed/7209680
British Heart Foundation / Get Britain Standing: https://www.bhf.org.uk/health-at-work/events/on-your-feet-britain
Power napping advantages: http://io9.com/the-science-behind-power-naps-and-why-theyre-so-damne-1401366016