Part of the "Myth Busting" series
Everyone knows what good posture is, right? When you're sitting in a chair you have a neutral pelvis, a straight back, shoulders back and chin tucked in. You brace your core. You NEVER cross your legs. You have your arms and elbows at 90 degrees to your chest. Ta da! That's it. Perfect posture. Now you just need monitor at eye height and a yoga ball or a special orthopaedic chair to sit on so you can hold that posture. All day.
After all, bad posture is the main cause of back pain, isn't it? Sitting slouched in a chair with your shoulders slumped forward causes muscle imbalances, and muscle imbalances cause pain - right?
I bet you're quite familiar with those statistics that pop up in Health and Safety at work. Have you seen diagrams like the ones above showing good sitting posture, and suggesting that certain postures cause a build up of pressure which is bad for your spine?
But what exactly does the evidence say about this? Is there such a thing as good posture? How prescriptive should we be? And do certain postures cause pain?
For this blog post, let's deal with static posture - that is, how you hold your body when you're sitting or standing or lying still. Recent research1 has actually completely dispelled the myth of there being a single "good" posture. In fact, the natural variations that we see between one person's posture and another is likely due to normal variations in their spines and joints. Some of us just have naturally curvier or flatter spines. Some of us have naturally wider or deeper hip and shoulder sockets. So we're not all going to feel comfortable sitting the same way. Posture is not "one size fits all" - we'll all feel comfortable sitting or standing or lying slightly differently. And that's fine.
Not only that, but our comfortable postures might change over time or in certain circumstances. Pregnant ladies often have an increased lower back curve to accommodate the extra weight of the baby in their abdomen. That's fine. That's a normal adaptation to a shift in the body's centre of gravity.
There is actually not a single piece of good evidence that suggests having a "good" posture will prevent back pain. There's also no evidence that correcting your posture to this arbitrary "good" is a reliable way to correct your pain.
Now some of you might be thinking "hang on a second, when I improved my posture my pain got much better". Some of you might even be thinking "wait a minute, Julia. YOU have told me to improve my posture at work - and it helped!" But let's not confuse causation with correlation. What I mean is, people who are in pain can have postures which provoke or irritate that pain, but it does not follow that posture causes pain.
Think of it this way: say you twist your ankle and sprain one of the ligaments. While you're waiting for the ligament to heal, you would (temporarily, because of the pain) tend to put more weight on the opposite foot when standing. If you forgot about your ankle and put more weight through it, it would start hurting. That change in posture provoked your pain, but it is not the cause of your pain.
In fact, when people without pain are researched, they have a whole range of postures which might be considered "bad". But in long-term follow-up studies these postures were not predictive of back pain, and correcting them did not tend to prevent back pain either.
One thing the research did suggest was that having a single fixed posture all day was more likely to be linked to pain. Even if that posture was "good" posture, holding your spine stiff in that position all day made it more likely to be sore. Having a range of different comfortable postures and switching between them during the day or getting up off the chair completely and moving around was helpful. But many people without pain do this naturally, without thinking about it.
So instead of thinking about good vs bad posture, we should be thinking about static vs dynamic posture.
If you have read some of my other blog posts, seen my Facebook live sessions or my TedX talk then you will know already that there is very rarely a singular cause of pain. There are lots of different things that your brain takes into account before deciding if you should feel pain, and back pain in particular has been shown to be a complex interaction between the biological (physical), psychological (stress, fear, etc) and social (work, family, support in life) parts of a person. This is known as the biopsychosocial model.
And here's something else to consider. I've already said that a person's posture can change naturally at different times in their life. But our postures also change a lot depending on our mood. Since pain is multi-dimensional, and psychological processes play a part in that, then we are much more likely to be in pain when we have low mood. And we are also much more likely to have stereotypical "bad" posture when we feel depressed - the clue is in the name, we do actually stoop "lower" when we feel "low".
So saying that "bad posture causes back pain" is overly prescriptive, highly simplistic and not backed up by the evidence.
- If you like checking out references then a good summary of this can be found in Slater et al, 2019 "Sit Up Straight: Time to Re-evaluate"↩