As with many medical questions, there is no consensus on what the best sitting position is.
There is more consensus that sitting commonly exacerbates and perpetuates low back pain. Poor sitting posture has also been implicated in the development and perpetuation of neck pain symptoms.
It makes sense that somebody who is 6 foot 5inches tall and somebody that is 5 foot 2 inches tall might not be comfortable sitting at the same desk.
In order to help people achieve the best sitting posture possible, some guidelines have been established in ergonomic circles. Let’s take a look at these.
Guidelines to the best sitting position possible
Get your angles right
The way I describe it to clients is to try and achieve 90 degree angles at your hinge joints successively.
So starting at the bottom…you need a 90 degree angle at your ankles (foot to shin bone). Your feet must be supported, if not on the floor then on a footrest.
You need to sit back in your chair so that there is a finger or two’s space between the back of your knee and the chair. This is in order for your pelvis to achieve a better position and be supported.
Your knees should be at a 90 degree angle… so this is where one needs to look at the height of your seat and adjust it accordingly.
Your hips need to be at a 90 degree angle to your body.
Your elbows should be as close to your side (90 degrees) as possible… the further away your arms are from your body, the more strain there is on your neck muscles.
You may need to raise or lower your desk or chair; or make use of a footrest to achieve all of these angles in succession.
Give the alignment of your spine some thought.
Common practice among physiotherapists is that if your spine is in a neutral position, you will have the least amount of strain on the structures of the spine (the vertebrae, discs, ligaments etc); and the stability muscles of the spine are in a more optimal position to do their job (which is to support the spine).
The specifics of a neutral spine are more difficult to describe and will be better explained by your physiotherapist, specific to your body type and restrictions, but as a general guide try and achieve something like this….
From the top: your head should be over your shoulders i.e. your chin must not poke forward, if it is, move it back as though making a double chin, once your head is ‘on your neck’, tuck your chin in ever so slightly ( without bending your neck, i.e. a slight nod of the head on the neck). The tip of your shoulders should be in line with your body horizontally (not slouched)
From the bottom: the neutral spine has more or less been achieved if you are sitting on your ‘sharp bum bones’. So, roll your pelvis forward so that your low back arches, as far forward as you can, and then slowly roll back until you feel the pressure through your bum bones. Your chair should provide you with support in the low back area to maintain this position. If not, you may need to adjust your back rest or get an external lumbar support.
Take a look at this earlier article for a step by step guide (there is even a video link of 2 minutes to help you get this right).
What about my screen?
Your screen should be directly in front of you. If you are looking to one side, there is unequal strain on your neck. If you work on multiple screens, you should align your whole body to face the screen that you are working on. If this changes regularly, you may benefit from a chair that swivels. In your ‘ideal’ sitting posture, your screen should be at a height that you can view your work by dropping your eyes 15 to 30 degrees (still maintaining your head on neck and chin tuck position).
Don’t forget to move…regularly.
Ideally, one does not want to be in any one position for any length of time, so try and change your position regularly during the day. This doesn’t mean you have to stand up every 30 minutes but try and move every 30 minutes, whether you stretch your arms up, lean back, twist your torso etc
If you need to move forward at your desk, lean forward from your hips (your middle)
Is sitting on a ball a good sitting position?
Little quantitative evidence supports the practice of exercise balls as an alternative to standard office chairs for prolonged sitting at computer workstations. The premise is that by sitting on an unstable surface, you get greater activation of your ‘core’ muscles and even burn a few extra calories. The studies reveal very little difference in muscle activation and a negligible increase in calorie burning (about one carrot extra) and there have been incidents of falls.
Some studies have found that the increase in muscle activation has caused an increase in disc pressure which is contrary to what you are hoping to achieve from your sitting surface. In one study, people were able to maintain a better pelvic position but after prolonged periods this became uncomfortable.
Conclusion: A ball may be a tool to change things up but as a replacement for an office chair, it’s not a good long term solution.
Would a standing desk be a better option?
To reduce sitting time, and in turn, improve health, some individuals have begun to implement standing desks or sit-stand workstations—that is, workstations that can adjust to either a seated or standing position.
Studies have found that prolonged standing has benefits to your cardio-metabolic health, with favourable effects on glucose levels, cholesterol levels and cardio-metabolic risk scores. Other studies are looking into the differences in creativity and reading comprehension between seated and standing workers.
Few studies have been conducted into the differences in strain on the back and neck. One study found that workers became uncomfortable after standing for a period of time (2 hours). This may be due to the fact that it is a change in their ‘normal posture’. This is a relatively new approach and more studies need to be conducted into the benefits and risks of such an intervention to provide an evidence-based approach to decision making.
Conclusion: Standing desks are great for their health benefits but ‘time on feet’ needs to be built up slowly since our office-bound bodies are deconditioned and adjustment time is important.
Movement is the cure
Internationally, experts are developing guidelines for office based workers on sitting times and changing positions as it is recognised that prolonged sitting is bad for your health on a broader scale.
Many guidelines suggest that workers who are predominantly desk based, should aim towards accumulating 2hrs/day of standing or light activity (light walking) time. The aim is to eventually progress toward a total of 4hrs/day. And this should be during work hours, not as an addition after work. Standing-based work, the use of sit-stand desks, or the taking of short active standing breaks are just a few ways to achieve this.
So, in conclusion, sit as best you can but even more important… move as often as you can. Movement is after all, medicine!!!!