Many of my clients worry about their bad posture. I know this because they often tell me about it before I even get as far as the physical examination. “I know my posture’s terrible,” they confess, in the same guilty way that someone might admit to their doctor that they eat too much fast food, or to their dentist that they haven’t been very good at keeping to their regular check-ups. I can almost see them bracing themselves for yet another lecture about sitting up straight. They’re often surprised when I tell them instead that actually, they’re about the same as most other people in that respect, and that it’s probably not a major cause for concern.

Perhaps you’re in a similar boat. If that’s the case, you’re certainly in good company, so let’s take a look at what the evidence tells us.

What do we mean by “bad posture”?

To a therapist, “poor posture” can mean lots of different things. It could be the way your pelvis tilts forward when you’re standing, the habit you’ve got of shifting most of your weight onto one leg if you have to wait in line for a while, the awkward way you hold your shoulders while playing the guitar, or the way you sit slumped at your desk on a Friday afternoon.

With so many uses of the term, it can become confusing to pin down what good posture looks like, even when we limit ourselves to a single position (like sitting, for example). In fact, to a large extent, good posture is in the eye of the beholder – there’s no gold standard for how a human being “should” stand or sit or move. One medical dictionary has this to say:

“Good posture cannot be defined by a rigid formula; it is usually considered to be the natural and comfortable bearing of the body in normal, healthy persons.”

That definition calls into question the very idea of an “ideal sitting position.” One study showed that when researchers asked subjects to hold a position often regarded as “good posture,” it turned out to be so unnatural that it couldn’t even be achieved without assistance, and required active effort to maintain. The researcher pointed out that “it may be that slumped postures are uncomfortable for the spine and may cause people some problems, but the science to actually test or prove that is really weak."
Another study, which examined spinal disc movement via MRI in a range of different seated positions, suggests that sitting up straight may not be best for your back after all, and recommends reclining your chair instead.

Is there any evidence that posture does (or doesn’t) contribute to pain?

Given the lack of consensus about what “good posture” even looks like, a lot of new-school physical therapists have started to be vocal about their skepticism of a link between posture and pain.
There are some studies which suggest that posture is likely to be less of a factor in various pain conditions than may have been previously thought (if, indeed, it has any effect at all). On the whole, though, there’s a distinct lack of evidence on this topic, so it’s hard to come down firmly on one side or the other.

It’s worth bearing in mind that these studies are mainly based on comparing healthy people with those who develop back pain. If you already have back pain then it may be a different story. Depending on the nature of your condition, you might well find that some positions aggravate it more than others and should be avoided on that basis—this is something to discuss with your physical therapist. And while there’s probably not a strong causal link between posture and pain, the reverse is not necessarily the case. In some cases, back pain may actually cause poor posture, as this small study hints.

Another consideration is that for many people, trying to force themselves to sit with good posture (or what they think good posture is) can cause them to be more tense and uncomfortable, and can sometimes make them more prone to developing pain. It’s entirely possible that worrying about your posture might make your back hurt more.

Is your posture the problem, or the lack of movement?

As most of us have experienced, staying in any one position for too long tends to become uncomfortable, if not painful. Some postures will tend to become painful more quickly than others (you can demonstrate this to yourself by deliberately choosing an awkward position to sit in), but even a comfortable position will start to nag at you if you stay there for hours on end—and perhaps this is a good thing, since it’s your body’s way of reminding yourself to move.

Changing position frequently, or getting up and moving around regularly, are simple and inexpensive ways to reduce the discomfort that goes along with being sedentary. If you’re willing to invest a little more money and effort, then a sit–stand desk allows you to switch between sitting down and standing up to work (although when we talked about these in a previous column, we discovered that most people aren’t motivated enough to make good use of them).

There is still some debate over whether prolonged sitting is itself a causative factor in chronic pain conditions, regardless of which sitting position you choose. What is reasonably certain, though, is that spending a lot of time sitting down is really bad for you in plenty of other ways. It’s been shown to increase the risk of heart disease, cancer, and diabetes, even among people who exercise.
So, perhaps we should worry less about how to sit better, and pay more attention to how we can reduce the time we’re sitting at all.

The verdict: your posture probably matters less than most people think.

It’s possible that there are circumstances where posture may be more of an issue, but there’s not enough evidence to be sure. We can’t even say for certain what the best sitting posture is, but we can be confident that it’s a good idea to avoid staying in any one position for too long at a time. There’s no one right way to sit or stand, but we’re all better off moving regularly.