Sitting on a chair for long hours has become very common these days. Due to our modern sedentary lifestyle, prolonged sitting has become an hour habit. Sitting for prolonged hours without ergonomic support can increase the risk of injuries.
Are chairs without backs better for you? A chair without backs or back support can increase the internal disc pressure and lead to chronic degenerative back issues. However, sitting without back support on a kneeling chair better maintains the lumbar lordosis relative to the standing posture.
As we spend most of our waking hour by sitting, study shows that sitting with proper back support can reduce sitting stress and improve comfort. They also suggested an optimal sitting posture that will increase comfort and offer better support in the back.
In this article, I will explain why lumbar support is essential for a chair, what it can do to your back if you sit without back or back support to a chair. I will also explain the effect of sitting on a kneeling chair and a flat chair.
Sitting without back or lumbar support
As I have mentioned above, sitting biomechanics found that disc pressure was considerably higher in an unsupported sitting than in standing. Also, without back support extensor muscles of the back.
They have mentioned that increasing backrest inclination and sufficient lumbar support decreases the disc pressure in a supported sitting.
By backrest inclination means, you should recline your chair’s backrest to at least 100 degrees of reclined position, and 1 to 2 cm of lumbar support from the backrest can improve your comfort, reduce intervertebral disc pressure.
If you are working from home and sitting in front of a computer for long hours, then you would understand that sitting without insufficient back support can make your back muscle fatigue, increases the risk of shoulder and neck issues, and you can suffer from a bad posture.
Although sitting causes back, pain is a controversial topic; back pain has increased a lot recently, indicating sedentary sitting. Every person suffers from back pain once in their lifetime. If you sit for long hours in an unsupported sitting, you will likely develop back-related issues.
So, sitting without back support is out of the equation. If you currently don’t have an ergonomic office chair, make sure your current chair has proper cushioning to your lumbar region.
You can check our article How to Make a Wooden Chair More Comfortable?, where I have explained making a wooden chair comfortable, which also makes the chair ergonomic.
If you do have a decent ergonomic office chair, you can recline your backrest to 110 to 130 degrees with proper lumbar support. This particular position has the lowest disc pressure in electromyography readings.
The inclination of the backrest is essential because one part of the bodyweight is shifted to the backrest. So, it decreases the load on the discs and back muscle strain. [source]
You can also further reduce the lumbar disc pressure and increase comfort by using an armrest. As ergonomic office chair comes with armrests so, you are covered.
Sitting on a kneeling chair and a flat chair
Research suggests that you can achieve correct sitting posture when the lumbar curve is similar in both sitting and standing positions. However, no study has demonstrated that such sitting postures prevent disc degeneration or low back pain.
Sitting on a kneeling chair may promote an anterior pelvic tilt and enhance lumbar lordosis as compared with sitting on a flat chair, probably for both slumped (relaxed) and upright (active) sitting.
According to this study, lumber curvature was found nearly 50% greater in standing position than sitting. Their study results show that sitting on a flat chair in an upright position has similar lumbar curvature to standing. However, this lumbar curvature significantly changes when you adopt a slumped posture.
In a kneeling chair, lumbar lordosis(curvature) is similar to standing posture even when you are sitting in a slumped posture.
If you sit relaxed without back or lumbar support, you are more likely to adopt a slumped posture because sitting in a upright position increases muscle activation, loading on the spine and cause muscle fatigue. So, it can lead to back injuries if you are sitting without a back for a long time.
So, sitting in a lordotic lumbar spine is preferable as it maintains a similar posture to standing. It also decreases the risk of degenerative disc disease.
Another study suggested that enhancing lumbar curvature using lumbar support on a chair can reduce back and leg pain.
If you sit with lumbar support on a chair will have great comfort as well as health benefits; on the other hand sitting on a kneeling chair is also a viable option.
Optimal seated posture
We all have our different kinds of sitting postures. However, those sitting postures are not optimal, and we end up developing back issues in the long run.
To achieve an optimal sitting posture, an ergonomic office chair is necessary. I am assuming you already have an ergonomic office chair. You can achieve an optimal sitting posture by following these criteria:
- Make sure you have sufficient lumbar support in a seated posture to rest the back muscles.
- The chair seat height should be less than the distance from knee to feet.
- You can sit against the chair seat back with knees at a 90-degree angle or more.
- Recline the backrest of the chair from 110 to 130 degrees.
- If your office chair has a synchro-tilt or swivel tilt mechanism, your seat will incline a few degrees, which is good because research suggests a 5 degree of seat incline.
- Adjust the height of your armrests, you can relax your arms on the armrests without your shoulders being hunched.
- When you sit in the above reclined position, 1 to 2 cm of lumbar support is essential.
This optimal seated posture with seatback recline, using armrests instead of arms hanging lower the disc pressure.
Proposals for an office chair
When we are seated in a chair for a while, we try to change our sitting posture by leaning forward and reclining in order to relax the back muscles periodically.
An ergonomic office chair can achieve an optimal sitting posture. So, Ergonomics of posture suggested the following proposal for an office chair.
- The chair should have a high backrest.
- Well-designed lumbar support, essential for optimal comfort.
- The chair should be possible to tilt the whole seat shell and the backrest.
- The high backrest should follow the “S-shape” of our posture. This design will provide better support in the lumbar region when sitting and reclining.
All the above features are available on modern ergonomic office chairs to enhance the optimal sitting experience.
Chair without backrest good or bad?
A chair without a backrest is not a good option to consider. Backrest support is essential to sit for an extended period of time and to relax back muscles. Without backrest, you need to sit upright, which requires muscle activation, loading on the spine, and muscle fatigue. So, you won’t be able to sit for a long period in this position.
It would be best if you considered a decent ergonomic office chair for optimal sitting experience. You can also go for a kneeling chair if you like.
If you would like to learn about ergonomic office chair. You can check our article “ What are Ergonomic Office Chairs and When Are They Necessary?”