The Ideal Sitting Posture: Does It Exist And How Can We Sit Properly?

11 min readJan 20, 2017

This post was originally published on airawear.com.

“Sit up straight,” the voice of a stern mistress pierces through the classroom. “And stop slouching!”

You must be familiar with such a character from your schooling years.

This is a teacher whose demeanour reminds you of a Victorian brought out of her own time. You know the one, with a hooked nose, thin lips and a hair bun tighter than her personality.

Victorian teacher or Tiger mom? No difference, really.

But instead of vilifying the strict teacher… I have to question something more important (as I always do).

Why sit up straight? Did it necessarily make me pay attention in class? Was it common but unquestioned wisdom that good posture makes us better students?

Now, you might wonder if sitting straight really is good posture. I mean, come on. Our backs still hurt after trying to sit upright for decades. What does this old hen know that I don’t?

As it turns out, you have to throw all conventional wisdom about sitting out the window.

Sitting straight isn’t the best posture. Furthermore, you shouldn’t even be sitting for a 2 hour lecture or meeting without moving at all.

To be frank, conventional wisdom is merely 50:50. It doesn’t work all the time, and when it does nobody questions how or why.

So what makes the draconian teacher wrong?

Our spines are similar to other mammalian spines. It’s the same with every quadruped furry creature out there.

Sorry, Rufus.

But we’re the only full-time bipeds in the house! The spine structure wasn’t evolved to be perfect on 2 legs, yet our spines take more pressure and weight, so to speak. Should it be that surprising we face some back problems? Probably not.

(Food for thought: anthropologists claim our back problems are byproducts of our imperfect evolution in walking on two legs.)

There’s also plenty of research that don’t follow the 90 degree, upright sitting standard. We’ll get to that in a bit.

As for now, follow through this article and you’ll be given a good fighting chance to:

End the frustrations of back aches while you quit looking like Quasimodo or Jar Jar Binks (simply apply your knowledge of sitting posture at work!)
Double your confidence level (backed by scientific studies): allow your loved ones, colleagues and boss feel different about you after improving your sitting posture
Boost your productivity when back pain and a “sleepy” posture can no longer hinder you from doing your best work
Feel 10 years younger whenever you work or drive, after you learn to bulletproof your healthy sitting habits
Be surprised as your muscle tightness gradually disappears from your shoulders, backs and hips (good news: you don’t have to resort to standing up for long periods to solve this!)
Shrink any risk of long-term injury that you may contract from a bad sitting posture

Instead of resigning to a life of back pain… Let’s dig deep into the ways of sitting, and find out who we should listen to.

Here’s a landscape preview of the sitting posture field.

There are different authorities and theories that support different ways of sitting. And it should be cautioned: just because a theory is more recent, or has more papers supporting it, doesn’t *necessarily* make it “more right” than other competing schools of thought.

So back to the question, “Is there an ideal sitting posture?”

Rather than announcing dismissively, “There’s no definite answer, pack up and go home folks”…

We say this, “There’s no definite answer, let’s go ahead and see what makes most sense to you after hearing everything”.

For instance, if you’ve been trying to sit at 90 degrees for the past 2 years and your back still hurts, you can try adopting a different angle. Or try switching up your sitting duration. The key idea is to test out whether expert and scientific recommendations work out for you.

So let’s dive into each school of thought!

A) Sitting upright at 90 degrees: going old school

This is what we can safely call conventional wisdom, as mentioned at the beginning.

To quote this 2012 paper studying spine curvature by Baumgartner et al.,

“Continuous upright sitting has been shown to be undesirable since the 1960s.”

So yes, this advice has been around before the rise of disco.

As to how it came about… We aren’t sure of the identity of the first person who dispensed this advice. But we can see why parents and teachers (like the Victorian hag at the beginning) repeat this advice to children worldwide.

After all, you can imagine how an upright sitting position gives a feeling of discipline in the room. It’s as if everybody’s gone all military, sitting straight like good soldiers. Furthermore, it feels like all eyes are on the person speaking and everyone is listening — even if they aren’t, heh.

Sitting upright isn’t the most harmful sitting posture either (it beats the stereotypical hunch you’d see in the programming department).

Still, there are reports that suggest sitting upright can strain your lumbar AKA your lower back. For some, it’s the muscles. Others? It’s the spine itself.

And in this 1999 study by Wilke et al.,

“Relaxed sitting on a stool with a normally straight back produced a pressure peak of 0.45 to 0.50 MPa, similar to pressure in standing.”

So even if you sit upright for 6 hours, it’s akin to the pressure put on your spine by standing for 6 hours too. Not too pleasant for your poor spine.

The same amount of pressure on your spine, really.

It’s easier to see why ergonomic chairs have those lumbar curves to support you. But sitting upright doesn’t utilize this back support, even if your butt is pushed back all the way into the seat.

Meanwhile,

B) Reclining between 110 to 130 degrees: the new right angle (geddit?)

This 1999 study conducted by Harrison et al. concluded that reclining at 110 to 130 degrees was optimal for the body.

It was discovered that:

At 110 to 130 degrees… The participants had the least amount of pressure on their spinal discs (those soft flat layers between the bones of your spine).

Meanwhile, the study itself recommended angling your back and backrest at 110 degrees, compared to 130 degrees. This is to avoid “translated forward head postures”. Or simply put, you don’t want a turtle neck while working and reclining sooo much at the same time.

Side note: The paper was wildly popular and mentioned in many current articles. Just try searching “best sitting angle” and you’ll see some still mention the 1999 paper.

More recently,

C) Reclining at 135 degrees: the more the merrier?

In 2006, a team of researchers at the RSNA concluded that 135 degrees of sitting recline would be optimal for sitting comfort on your spine. And it reports that the upright posture leads to spinal disc movement, putting strain on the spine:

“Disk movement was most pronounced with a 90-degree upright sitting posture. It was least pronounced with the 135-degree posture, indicating that less strain is placed on the spinal disks and associated muscles and tendons in a more relaxed sitting position.”

In turn, the disc movement can cause misalignment in your spinal disc material… An unfortunate precursor to gaining a slipped (herniated) disc, and therefore back pain.

You can probably understand why sitting at 90 degrees is physically different compared to these other 2 reclining camps of thought. It’s a matter of strain placed on the lower back.

But what’s the real difference between the two reclining schools of thought? A matter of degree?

(I swear these horrible wordplay jokes just come to me.)

Both sets of reclining angles have less pressure placed on the spinal discs. So what’s the actual difference?

It should be noted that the RSNA press release was rather limited. It did not say why the team chose a 135 degree reclining angle, instead of 110–130 degrees (a more achievable angle range considering most office chairs).

To truly recline at 135 degrees in your office can be inconvenient. Your neck would have to tilt downward significantly to look at your computer monitor. And unless your entire workspace has been modified to suit that 135 degree recline (e.g. table, keyboard and computer angles are adjusted accordingly)…

Following this recommended sitting angle will have its own set of environmental barriers to overcome.

90 degrees, 110 degrees, 135 degrees even… These angles of seated reclination aren’t the only thing to consider when learning what works best.

Furthermore, I want to be realistic with you. Who on earth actually measures their back angle?

I spoke too soon.

Okay, umm. What are the odds you own such a wearable tech device then?

Here’s something that’s 1000x much easier to track ON YOUR OWN:

Time.

Specifically, there are two things you can measure:

Duration of sitting and
Frequency (How often you change your sitting position)

Wait what? What has time got to do with posture?

Check this out, from a 2016 paper that considers the relationship between sitting posture and back pain:

“The optimal occupational sitting position and sitting behaviour has been extensively discussed in the literature in recent years. The long-standing doctrine of an ideal sitting position that is “as upright as possible” has been strongly questioned (Marx and Wirth, 1996) and has been slowly replaced by the concept of “Dynamic Sitting”, where sitting positions are continuously altered (Lueder, 1983 and van Dieen et al., 2001). A literature review conducted by Pynt et al. (2001) suggests that there is no ideal sitting posture. According to these authors, regular movements and a seated posture with preferred lumbar lordosis is essential for preventing LBP.”

Hate the technical jargon? Me too. So simply put:

The topic (ideal sitting posture) has been getting more popular recently
Sitting upright is probably outdated wisdom
There are skeptics who think there’s no ideal posture
Movement at consistent intervals is highly recommended if you want to prevent lower back pain

Let me emphasize the important stuff. Again:

Movement at consistent intervals is highly recommended if you wanna prevent lower back pain.

Thus, in order to counter back pain, it’s time to be mindful of this time dimension even when doing something as mundane as sitting.

Also, consider this.

Bushmen and tribesmen — unlike us cube farmers and desk warriors — have no back problems. They own healthy, strong backs, with J-shaped spines. Our ancestors as hunter-gatherers shared a similar lifestyle as these guys (back when “apple” simply referred to a fruit).

They were moving around all day, much unlike us in developed countries. So they never had to be conscious about how long they sat at one go, and how often they moved around in a non-sitting position.

We on the other hand would be wise to take note of how often we move away from the chair.

So far we’ve only been talking about the reclining angle of your back: which has been a hot matter that’s been debatable for years.

But how about the rest of your body when you sit? Even if you have a proper angle, your neck could still develop a bad habit of thrusting itself forward like a turtle. Or your arms could be in positions that strain your tendons unnecessarily.

We address the issue right here. And you get to learn how to adopt the principles of ergonomics into your sitting posture:

Sit back fully in the chair: There should be a 2 to 3 finger breadth-space between the seat cushion and the back of your knees when sitting. Your thighs should be parallel to the floor.

Feet planted firmly on the floor: Your feet should rest comfortably on the floor or on a footrest if you need to. As a result, your knee angle should be about 90 degrees. Your feet help your spine by taking some of your weight off it. Use a box as a substitute if you don’t have a footrest. Also, avoid crossing your legs as this adds pressure to your lower back.

Your shoulders are relaxed: If you feel that your shoulders are hunching forward or tight, chances are you need to re-adjust your desk or chair. To find out more, check out our post on creating an ergonomic space for yourself to work in.

Your elbows are close to your body: Your forearms should be on the armrests. Your elbows should be near your waist (right where they should be in a neutral position). And thus, you reduce the strain on your shoulders. If you are unable to keep your elbows close to your body, your keyboard and mouse are probably too far away from you.
Your wrists are straight: Keeping them straight reduces strain on the wrists. If you can’t do this, your desk or chair might be at the wrong height, or you keyboard is placed wrongly.

Your neck is straight: We tend to slowly move our head closer to the screen as we work. But your head is heavy (11lbs or 5kg on average!). Ensuring that it is in line with your spine helps reduce strain on your neck. You can consider getting a chair with headrest or even adjusting the size of the items on your screen to prevent moving your head from the neutral position.

Pro-tip: to ensure your neck is straight, make sure your ears are aligned to your shoulders, when you’re viewed from the side (specifically the deltoids).

Your back is supported by the lumbar curve of the chair: The lower back avoids slouching in an outward arc when something is pressing against it.

You get off the chair every 30 to 60 minutes. This is to ensure your muscles, bones and joints are doing their job that they were designed to do (i.e. moving around in the environment).

Here are the main points once again:

Sitting upright isn’t the best posture, despite centuries of insisting that it is
A backward recline (110 to 135 degrees) is more ideal, with your butt and back against the backrest
BUT reclining at 135 degrees may be inconvenient to work with (imagine how much you need to lean back and still look straight ahead at your desk!)
Limit your duration of sitting in one session — time may play a larger factor in your backaches than your posture

And lastly, it’s never too late to start taking care of your own back and health, so start today by learning to adopting a better sitting habit (like your posture) today!

Did you like this article? Then hit the ❤ button below to let us know!

Originally published at airawear.com on January 20, 2017.