The Ergonomics of a Chair Explained
What does the term ‘Ergonomic’ mean?
Concerning the ergonomics of a chair, ergonomics looks at how your chair can be designed and arranged to best complement easy and safe human interaction. Ergonomic chairs are specifically designed for maximum comfort and efficiency, supporting the human body by correcting posture and introducing long-term health benefits as a result.
What makes a chair ‘Ergonomic’?
The features of an office chair are enhanced in ergonomic office chairs to improve your posture and offer corrective support. A good ergonomic chair is a fully adjustable office chair. Seat height, depth and angle are all vital to enhance the ergonomics of a chair and provide complete comfort.
Additionally, the backrest should have a height and tilt, the lumbar should be inflatable and the arms should be adjustable. These features combined will create the perfect adjustable office chair that multiple people can use.
Choosing an adjustable office chair is vital if the chair is intended for use by multiple people of different body types. The comprehensive ergonomics of a chair meant for many will provide the features of an office chair that you and your employees need to be correctly supported and comfortable while working.
If you’re buying an adjustable office chair for personal use at home, you should consider your bodily dimensions for the best fit possible.
Those who work in offices know all too well that sitting for prolonged periods can cause serious long-term health implications that you may already be feeling the effects of. We should all think about how we sit and how long, as well as the importance of keeping mobile and active to prevent pain.
Sitting causes many stresses in our bodies, particularly in the spine. This fact has recently become more recognised by health professionals, with Public Health England and The Office for National Statistics reporting that “Musculoskeletal (MSK) conditions are the biggest cause of working days lost in the UK aside from coughs and colds.”
‘’In 2020, MSK problems were the second most common cause of sickness absence, which accounted for 20.8 million days lost in work (17.5% of total sickness absence), surpassed only by absence due to minor illnesses such as cough and colds’’
Taking into account the ergonomics of a chair and how beneficial it could be to your health is vital.
The Ergonomics of a Chair Explained
Seat height
The ergonomics of a chair start with seat height. The seat height should allow you to place your feet flat on the floor, which is essential to maintain correct positioning for your feet, legs, and hips. A chair with an adjustable seat height is essential because we’re all different and will require different elevations! As most work desks are at a fixed height, it is important to have an adjustable office chair that can be altered to suit you and your workstation.
Seat width and depth
Seat depth is important to allow you to fully engage with and be supported by the backrest. When sitting upright with your back to the backrest and your bottom to the back of the seat, there should be a two to three-finger gap between the edge of your seat and the back of your knees.
If your seat is too far forward, it may put undue pressure on the back of your knees, preventing the backrest from supporting you. Alternatively, if the seat is too far back, your thighs will not be supported.
Seat tilt
Good ergonomic chairs will have a seat tilt. This will allow for the correct positioning of the pelvis and neutral alignment of the lower back and lumbar region of the spine. Anterior pelvic tilt is a posture issue that affects almost everyone who spends most of their workday sitting. It is vital to keep the pelvis in a neutral position when sitting, with 80-degree angles at the hips, knees and ankles (with your knees slightly lower than your hips).
Backrest Lumbar support
The support given to your lower back is an essential feature of the ergonomics of a chair. Most back issues are found in the lower back, which can be exacerbated by an unsupportive chair. Ergonomic chairs support the natural ‘S’ shape of the spine, which helps to prevent slouching and reduce stress on the spine and pelvis.
An adjustable backrest will allow users to align the curve in the chair with the curve in their spine and provide optimal support. Furthermore, the height adjustment of the backrest allows for correct lumbar support and full back contact. An inflatable lumbar is ideal to allow you to alter the pressure and support your lower back.
Backrest Tilt or Recline
The tilt of your backrest should be easily accessible from your seated position and include ‘free float’ and ‘locking’ lever options or a synchronised movement (the seat and backrest move together at a 2:1 ratio). Using these beneficial features of an office chair will encourage the backrest to fully support your back and maintain correct positioning. It will remove some weight from your upper body and reduce the pressure on your spinal disks and muscles.
Swivel
The swivel enables manoeuvrability, making it easier to reach different points of your desks without having to strain.
Armrests
A good adjustable office chair will have armrests that are adjustable in height as a minimum. They help to reduce tension in the upper body, shoulders and neck and allow the shoulders to relax, relieving strain and tension. If you are larger or slim then width and depth adjustable armrests are a really good option to achieve maximum support.
Headrest.
Headrests support the back of the head and the upper neck, reducing tension in the muscles of the shoulders, neck and upper torso.
Upholstery
The upholstery should be comfortable, FR-treated, hard wearing and stain resistant. The choice of the material you use for your upholstery will be influenced by your budget as a large number of options are available.
Castors (Wheels)
Wheels can be selected to suit the type of flooring you have. If you have any particular mobility requirements such as difficulty moving into or out of a chair then braking loaded or unloaded castors are a good option.
‘Fine tuning’ options….
If you have specific pain then further fine-tuning the ergonomics of a chair can achieve the perfect ‘fit’ of chair for you. Some of these options can include,
- Inflatable thoracic Support
An inflatable cushion in the upper centre of the backrest helps to stop slouching and increases the contact area with the backrest, between the shoulder blades. It also helps to reduce pain and discomfort in the shoulders and neck.
- Airflow Seat
A ‘reactive sit’ is produced by the dual air chambers cell in the seat cushion. Provides cushioning to your ‘sit bones’ and increases core strength and reduces sciatic pain.
- Coccyx Cut-out
This soft pocket at the centre back of the seat cushion is a discrete solution to coccyx pain as it relieves pressure on the tailbone.
Additional Considerations
When choosing your ergonomic office chair, you should also consider how long you will be sitting in it every day, as the longer you are planning on using the chair, the more adjustable options you’ll want to consider.
Sitting Correctly….
And remember, to truly feel the benefit of the ergonomics of a chair, you should ensure to sit correctly. You can do this by keeping an arm’s length away from your computer screen while keeping your arms parallel to the floor. Ideally, the top of the monitor should be at eye level.
Furthermore, you should sit up straight and avoid slouching. Shoulders back, chest ‘open’, your neck should be in a relaxed and neutral position.
Your bottom should be positioned to the back of the seat so your chair backrest fully engages with your back and your legs are supported.
Finally, you should sit with both feet flat on the floor, avoiding crossing your legs to allow correct blood circulation within your legs.